Blocky hydroxyethylcellulose, derivatives thereof, process of making, and uses thereof

0001This application claims the benefit of <patcit id="pcit0001" dnum="US65386405P" dnum-type="L"><text>U.S. Provisional Application No. 60/653,864, filed February 17, 2005</text></patcit>.

FIELD OF INVENTION

0002The present invention relates to cellulose ether compositions, processes for making the composition and uses thereof in functional systems. More specifically, this invention relates to non-uniformly substituted ("blocky") hydroxyethylcelluloses (HECs). This invention also relates to processes for making blocky HEC and uses thereof in functional systems.

BACKGROUND OF THE INVENTION

0003Hydroxyethylcellulose (HEC) is a cellulose ether usually made by reacting alkali cellulose with ethylene oxide (EO). In general, the molar ratio of EO to the anhydroglucose units of cellulose is higher than 1.5 to provide adequate water-solubility to the cellulose backbone. HEC is a water-soluble/water-swellable polymer that generally is used to viscosity aqueous media of functional systems such as personal care and household products, paints, construction material products, paper coatings, oilfield media, emulsions, latex components, etc. Furthermore, high molecular weight HEC is used in the pharmaceutical industry as an excipient to provide a swellable diffusion barrier in controlled release applications.

0004In commercial HECs that are made by a single-stage ethoxylation of cellulose, the hydroxyethylene substituents are nearly randomly distributed among the anhydroglucose segments of the polymer. Examples of prior art that disclose the preparation of HEC are <patcit id="pcit0002" dnum="US2572039A"><text>US Patents 2,572,039</text></patcit>, <patcit id="pcit0003" dnum="US2682535A"><text>2,682,535</text></patcit>, <patcit id="pcit0004" dnum="US2744894A"><text>2,744,894</text></patcit>, and <patcit id="pcit0005" dnum="US3131177A"><text>3,131,177</text></patcit>. Another commercial HEC product is a more highly substituted HEC in which the ethylene oxide is reacted in two-steps thereby reducing the amount of unsubstituted anhydroglucose units. This results in the formation of a cellulose derivative that is less susceptible to enzymatic degradation, i.e, enhanced resistance to biodegradation. Examples of prior art that disclose the preparation of this type of HEC are <patcit id="pcit0006" dnum="US3131176A"><text>US Patent 3,131,176</text></patcit>, <patcit id="pcit0007" dnum="CA1014289"><text>Canadian Patent 1014289</text></patcit>, and US Patent Application <patcit id="pcit0008" dnum="US200510139130A1"><text>US 200510139130 A1</text></patcit>. The solution viscosities of HECs with these types of EO substitution patterns usually depend on the molecular weight of the cellulose backbone.

0005Furthermore, HECs can be modified with additional substituents to improve functionality. For example, <patcit id="pcit0009" dnum="US4228277A"><text>US Patent No. 4,228,277</text></patcit> discloses the use of long chain alkyl modifiers having 10 to 24 carbon atoms. Another example of a modified HEC is disclosed in <patcit id="pcit0010" dnum="US4826970A"><text>US Patent No. 4,826,970</text></patcit> that describes a carboxymethyl hydrophobically modified hydroxyethyl cellulose ether derivative (CMHMHEC) that is used as thickeners and protective colloids in water based protective coating compositions. <patcit id="pcit0011" dnum="US4904772A"><text>US Patent No 4,904,772</text></patcit> discloses a water-soluble HEC derivative that has a mixed hydrophobe having two or more hydrophobic radicals having 6 to 20 carbons whereby one of the hydrophobic radicals has a carbon chain length that is at least two carbon atoms longer than that of the other hydrophobic radical. <patcit id="pcit0012" dnum="US4663159A"><text>US Patent 4,663,159</text></patcit> discloses a water-soluble, cationic hydroxyethyl cellulose.

0006Commercial HEC products are the thickeners of choice in many industries because they provide the desired rheology and thickening efficiency. Notwithstanding, a need still exists for an HEC-based rheology modifier that would be more efficient in thickening aqueous systems and interact more strongly with components in the system and/or with itself so that additional desired rheological properties can be achieved.

SUMMARY OF THE INVENTION

0007The present invention is related to "blocky" HEC.products that have unique thickening efficiency in neat solutions and functional systems. In other words, the HECs of the instant invention show associative properties that are unknown in commercial HEC products. An advantage of this product is that it provides a much higher solution viscosity than regular commercial HEC at similar concentrations and molecular weight. Consequently, a lesser amount of the HEC used in the present invention can produce comparable or better viscosity relative to analogous commercial HECs of similar molecular weight. The HECs used in the present invention form solutions that have a high elasticity that is characteristic of a strongly associative polymer network as well as unique adsorption characteristics and interaction with media components. The gelling properties and suspending properties of the present invention are better than similar HEC products of the prior art.

0008The present invention is directed to compositions comprising HECs that have hydroxyethyl groups that are non-uniformly distributed on the cellulose backbone, wherein the ratio of unsubstituted anhydroglucose trimers to the most frequently occurring substituted anhydroglucose trimers (U3R) is greater than 0.21 and the hydroxyethyl molar substitution is greater than 1.3 and less than 5.0 and wherein the HEC is a non-modified HEC that does not contain secondary substituents and the unsubstituted trimer ratio is measured as described in the section "Unsubstituted Trimer Ratio (U3R) Determination".

0009The present invention is further directed to a slurry process for making the above mentioned HEC composition comprising <ol id="ol0001" compact="compact" ol-style=""><li>A) mixing and reacting cellulose, water and a base reagent in an organic solvent for a sufficient time and at a sufficient temperature in order to form a first base reagent cellulose mixture, wherein the water to anhydroglucose (AGU) molar ratio is in the range of 5 to 35 and (a) the base reagent to AGU molar ratio is greater than 1.6 or (b) the base reagent to AGU molar ratio is less than 0.4</li><li>B) <ol id="ol0002" compact="compact" ol-style=""><li>(i) when (a) is used from Step A, then sufficient acid is added in order to reduce the base reagent concentration to a base reagent to AGU molar ratio of no less than 0.6 to form a second base reagent cellulose mixture, or</li><li>(ii) when (b) is used from Step A, then sufficient ethylene oxide is added and reacted at a sufficient temperature and for a sufficient time to form a HEC product with a hydroxyethyl molar substitution of less than 1.3, followed by additional base reagent to adjust the base reagent to AGU molar ratio to greater than about 1.0 to form a base reagent HEC mixture, and</li></ol></li><li>C) then adding to the second base reagent cellulose mixture from B(i) or to the base reagent HEC cellulose mixture from B(ii) a sufficient amount of ethylene oxide and reacting at a sufficient temperature and for a sufficient time in order to form the final HEC composition.</li></ol>

0010The present invention is also related to a functional system composition including the non-uniformly substituted HEC composition, wherein the functional system is selected from the group consisting of personal care compositions, household care compositions, pharmaceutical compositions, building and construction compositions, emulsion polymerization compositions, oil field servicing fluid compositions, civil engineering servicing fluid compositions, paper coating compositions, paper making compositions, architectural coating compositions, industrial coating compositions, printing ink compositions, adhesive compositions, and mineral processing and recovery compositions.

BRIEF DESCRIPTION OF THE DRAWING

0011<figref idref="f0001">Figure 1</figref> shows a bar graph of the ethylene oxide distribution profile of a HEC polymer.

DETAILED DESCRIPTION OF THE INVENTION

0012It has been surprisingly found that a HEC thereof having a non-uniformly or blocky substitution pattern can produce unique rheology that has not been noted prior to this invention.

0013The present invention is directed to blocky HECs in which a large fraction of the anhydroglucose units (AGU) in the cellulose backbone are not substituted with ethylene oxide (EO). Upon degradation, these unsubstituted anhydroglucose units exist as monomers and oligomers. The characteristic that makes these blocky HECs unique is an unsubstituted trimer ratio (U3R) that is greater than 0.21, preferably greater than 0.235, and a hydroxyethyl molar substitution that is greater than 1.3 and less than 5.0 preferably less than 4.0. This unique class of HECs shows associative behavior through hydrogen bonding and exhibits significantly higher solution viscosities as compared to other classes of HECs with similar hydroxyethyl molar substitution (HE MS) and cellulose molecular weight. Furthermore, this non-uniformly substituted HEC provides a unique template for reacting hydrophobes that are concentrated in the EO-rich regions in a non-uniform manner to achieve novel rheological properties.

0014In accordance with the present invention, the preferred process for making a non-uniformly substituted HEC product requires a two-step alkalization of the cellulose, while only a single-stage hydroxyethytation is necessary. This differs from the two-step hydroxyethylation that has been described in prior art to improve the enzyme resistance of HECs. The initial alkalization step is performed at an alkali to AGU molar ratio higher than 1.6 and at a water to AGU molar ratio in the range of 5 to 35. Next, the alkali cellulose is neutralized with an acid to an alkali to AGU molar ratio greater than 0.6, preferably between 1.2 and 1.0. The alkali neutralization step may be done as a single addition, multiple additions, or a continuous addition of the neutralizing aid, with or without the presence of ethylene oxide. Upon completion of the hydroxyethylation, the product can be purified, dried, and ground as known to those skilled in the art.

0015Non-uniformly substituted HEC can be produced using a "reverse" two-step alkalization process as herein described. In this case, the cellulose is partly alkalized at a caustic to AGU molar ratio that is insufficient to open up the cellulose fibers. Typical alkali to AGU molar ratios are between 0.2 and 0.4 and water to AGU molar ratios are in the range of about 5 to 35. The cellulose is first hydroxyethylated to less than 1.3 at this stage before more alkali is added in the second stage to reach alkali to AGU molar ratios between 1.0 to 2.0, preferably between 1.0 and 1.4. After sufficient time, the intermediate HEC is further hydroxyethylated to achieve the final HE MS.

0016In the slurry process of the present invention, organic solvent used in this process is selected from ethanol, isopropanol, tert-butanol, acetone, methyl ethyl ketone, dimethoxyethane, and mixtures thereof. This slurry process uses alkalis that are selected from lithium hydroxide, sodium hydroxide, potassium hydroxide, and mixtures thereof. The raw cellulose starting material used in the process for making the blocky HECs can be cotton linters, wood pulps or mixtures thereof.

0017The process and process conditions determine how the EO is distributed along the cellulose backbone. Products used in the invention are characterized and can be differentiated from HECs made by prior art by reducing the polymer down to monomers and oligomers and measuring the degree of unsubstituted oligomers, more specifically unsubstituted trimers. A novel parameter called the unsubstituted trimer ratio (U3R) can be defined as the ratio of the molar fraction of unsubstituted trimers to the molar fraction of the most abundant class of (hydroxyethyl-substituted) trimers, with 0 ≤ U3R ≤ 1.0. U3R is measured by a mass spectrometric technique that is described below. The U3R of the HECs used in present invention are equal to or more than used in 0.21, preferably greater than 0.235.

0018Trimers, oligomers with a degree of polymerization (DP) of 3 anhydroglucose units, and other compounds of structure 1 are made by partial methanolysis of permethylated HEC derivatives. It is assumed that the cleavage of the permethylated HEC-backbone is a random process and that the formed oligomers of structure 1 have an EO-distribution that is representative for the EO-distribution of the whole sample. <chemistry id="chem0001" num="0001"><img file="EP1858970B2_D0001.tif" /></chemistry>

0019In general, permethylated derivatives of HEC polymers can be prepared by the methylation reaction that is applied in the methylation analysis procedure for polysaccharides. (See publications of <nplcit id="ncit0001" npl-type="s"><text>F.-G. Hanisch, Biological Mass Spectrometry, 23 (1994) 309-312</text></nplcit>; <nplcit id="ncit0002" npl-type="s"><text>B. Lindberg, U. Lindquist and O. Stenberg, Carbohydrate Research, 170 (1987) 207-214</text></nplcit>; and<nplcit id="ncit0003" npl-type="s"><text> P.W. Arisz, J.A. Lomax, and J.J. Boon, Carbohydrate Research, 243 (1993) 99-114</text></nplcit>.)

UNSUBSTITUTED TRIMER RATIO (U3R) DETERMINATION

0020More specifically, in the present invention, the investigated HEC polymers are dissolved or swollen in dimethyl sulphoxide (DMSO). The hydroxyl groups in the polymer are deprotonated using a lithium methylsulphinyl carbanion solution in DMSO and they are converted to methoxyl groups by the reaction with methyl iodide.

0021The obtained permethylated HEC polymer is purified. More specifically, the permethylated HEC polymer is extracted in three extraction steps with chloroform from an aqueous DMSO layer that is acidified to pH &lt; 2 with hydrochloric acid. The pooled chloroform extracts are washed four times with water. Some methanol is added after the last wash step and all solvents are evaporated.

0022The permethylated polymer is partially degraded by methanolysis. More specifically, the permethylated polymer is dissolved / swollen in methanol. Sufficient hydrochloric acid in methanol is added to get a hydrochloric acid concentration of about 0.50 molar. The sample is dissolved completely at 50°C for 15 minutes. Partial methanolysis is done at 70°C for 2.5 hours. The reaction is quenched by the addition of 2-methyl-2-propanol and all solvents are evaporated, yielding a residue that is composed of a mixture of oligomers of structure 1.

0023The residue is dissolved in methanol and a fraction of this sample is mixed with 2,5-dihydroxybenzoic acid solution that is spiked with sodium iodide. Mass spectra of the oligomer mixture are recorded with a Bruker Reflex 11 MALDI-TOF-MS (matrix assisted laser desorption ionization - time of flight - mass spectrometer), which instrument is equipped with a microchannel plate detector. The compounds 1 are measured as their sodium ion adducts. The mass numbers of the monoisotopic mass peaks of the trimers are <i>m</i>/<i>z</i> 667.32, 711.34, 755.35, 799.39. It is assumed that all trimers are measured with equal probability, independent of their molar HE-substitution, chain length of the substituents and their positions in the anhydroglucose residues.

0024Trimer fractions are derived by two data processing steps from the measured peak intensities of their monoisotopic mass peaks. First the background signal of the MALDI spectrum is subtracted from the measured peak intensities. Secondly, mainly due to ¹³C-isotopes that are incorporated in structure 1 the monoisotopic mass peaks make up only 70.6, 68.9, 67.2, 65.6%, of all isotopes of trimers having 0, 1, 2, 3, etc attached EO-units, respectively. Unfortunately, the peak intensities of ¹³C-isotopes can not be measured accurately by MALDI-TOF-MS because of the recovery time that is needed for the microchannel plate detector after an intense mass peak has been recorded. In order to compensate the signal for the missing contribution of ¹³C-isotope peaks, the background corrected monoisotopic mass peak intensities are multiplied by a correction factor that is calculated from the theoretical isotope composition of the trimers. This factor increases with increasing number of C-atoms in 1, and values have been used of 1.417, 1.452, 1.488, 1.525, etc for trimers having 0, 1, 2, 3 attached EO-units, respectively.

0025<figref idref="f0001">Figure 1</figref> shows an example of the EO-distribution profile of trimers that are derived from a HEC polymer. The fraction of unsubstituted trimers is indicated in gray. The most abundant class of trimers in this example is that of trimers with 7 attached EO-units. This class is indicated in white. The unsubstituted trimer ratio, i.e. the gray fraction divided by the white fraction, is calculated to be 0.121 for this example. It should be noted that the number of EO-units in the most abundant class of trimers varies, depending on factors as the molar substitution of the HEC and the process type by which the HEC was made, for example.

0026The HEC used in the present invention does not contain secondary substituents such as nonionic, cationic and anionic substituents and mixtures thereof.

APPLICATIONS:

0027Many of these HEC samples exhibit novel and highly desirable rheology and performance properties in end use systems.

0028In accordance with the present invention, the viscosity builds up not only by means conventional to HEC, but also is boosted significantly by molecular association. The association leads to network formation and gel-like rheological properties in water and aqueous based functional systems that are shear reversible. The HECs used in the present invention have been shown to lower the HEC use-level needed and to provide unique rheological attributes as compared to commercial HECs available today.

0029Furthermore, these HECs may be used in applications where there is a need for a specific rheology characteristic, e.g., viscosity, thixotropy, yield stress, elasticity, or solid state characteristics such as thermoplasticity and film flexibility. Examples of functional systems includes aqueous based coatings (e.g., latex paints), building and construction materials. (e.g., cements, plasters), personal care products (e.g., skin care, hair care, oral care, nail care, and personal hygiene products), household care products (e.g., industrial cleaning liquids, pet care products), pharmaceuticals (e.g., excipients for tablets, capsules, and granules), oilfield applications (e.g., drilling fluids, completion fluids, and fracturing fluids), civil engineering, printing inks, adhesives, paper coating formulations, and retention and drainage aids in paper making.

0030In accordance with the present invention, the functional system can either be prepared in a continuous or batch process and either in a stepwise addition of the ingredients or a simple mixing of all of the ingredients at once. The order of addition of the ingredients can also vary over a wide range of additions. For example, the functional ingredients can be individually added one at a time to the formulation or all at once or the blocky HEC products can be added directly to the formulated ingredients in a single step. Hence, the process of thickening an aqueous based functional system (e.g., personal care products, household care products, oil field servicing fluids, civil engineering servicing fluids, paper coating products, paper making compositions, building and construction fluids, mineral processing products, and water based protective coatings such as architectural and industrial coatings), includes adding and mixing a sufficient amount of the blocky HEC polymer used in the present invention that is compatible with the aqueous based functional system to thicken the functional system. The resulting functional system has comparable or better rheology and viscosity properties as compared to when using similar thickening agents including commercial HECs.

<u>PERSONAL CARE</u>

0031In accordance with the present invention, when the composition is a personal care composition, it includes. (a) from 0.1 % to 99.0 % by weight of the vehicle component and (b) at least one active personal care ingredient.

0032In accordance with the present invention, the personal care active ingredient must provide some benefit to the user's body. Personal care products include hair care, skin care, oral care, nail care, and personal hygiene products. Examples of substances that may suitably be included in the personal care products according to the present invention are as follows: <ol id="ol0003" compact="compact" ol-style=""><li>1) Perfumes, which give rise to an olfactory response in the form of a fragrance and deodorant perfumes which in addition to providing a fragrance response can also reduce body malodor;</li><li>2) Skin coolants, such as menthol, methyl acetate, methyl pyrrolidone carboxylate N-ethyl-<i>p</i>-menthane-3-carboxamide and other derivatives of menthol, which give rise to a tactile response in the form of a cooling sensation on the skin;</li><li>3) Emollients, such as isopropyl myristate, silicone oils, mineral oils and vegetable oils which give rise to a tactile response in the form of an increase in skin lubricity;</li><li>4) Deodorants other than perfumes, whose function is to reduce the level of or eliminate micro flora at the skin surface, especially those responsible for the development of body malodor. Precursors of deodorants other than perfume can also be used;</li><li>5) Antiperspirant actives, whose function is to reduce or eliminate the appearance of perspiration at the skin surface;</li><li>6) Moisturizing agents that keep the skin moist by either adding moisture or preventing moisture from evaporating from the skin;</li><li>7) Cleansing agents that remove dirt and oil from the skin;</li><li>8) Sunscreen active ingredients that protect the skin and hair from UV and other harmful light rays from the sun. In accordance with this invention a therapeutically effective amount will normally be from 0.01 to 10% by weight, preferably 0.1 to 5% by weight of the composition;</li><li>9) Hair treatment agents that condition the hair, clean the hair, detangle hair, act as styling agents, volumizing and gloss agents, anti-dandruff agent, hair growth promoters, hair dyes and pigments, hair perfumes, hair relaxer, hair bleaching agent, hair moisturizer, hair oil treatment agent, and anti-frizzing agent;</li><li>10) Shaving products, such as creams, gels and lotions and razor blade lubricating strips;</li><li>11) Tissue paper products, such as moisturizing or cleansing tissues;</li><li>12) Beauty aids, such as foundation powders, lipsticks, and eye care; and</li><li>13) Textile products, such as moisturizing or cleansing wipes.</li></ol>

0033In personal care compositions, the rheology modifiers used in the present invention can be used either alone or may also be used in combination with other known rheology modifiers including, but not limited to, polysaccharides (e.g., carrageenan, pectin, alginate), cellulose ethers, biopolymers (e.g., xanthan gum), synthetic polymers, and abrasive/thickening silicas.

<u>HOUSEHOLD CARE</u>

0034In accordance with the present invention, when the composition is a household care composition, it includes (a) from 0.1 % to 99.0 % by weight of the vehicle component and (b) at least one active household care ingredient

0035In accordance with the present invention, the household care active ingredient must provide some benefit to the user. Household care products include fabric care, laundry detergent, hard surface cleaner, industrial institutional liquid soaps, and dish detergents. Examples of active ingredients or substances that may suitably be included according to the present invention are as follows: <ol id="ol0004" compact="compact" ol-style=""><li>1) Perfumes, that give rise to an olfactory response in the form of a fragrance and deodorant perfumes that in addition to providing a fragrance response can also reduce odor;</li><li>2) Insect repellent agent whose function is to keep insects from a particular area or attacking skin;</li><li>3) Bubble generating agent, such as surfactants which generates foam or lather;</li><li>4) Pet deodorizer such as pyrethrins that reduce pet odor;</li><li>5) Pet shampoo agents and actives, whose function is to remove dirt, foreign material and germs from the skin and hair surfaces;</li><li>6) Industrial grade bar, shower gel, and liquid soap actives that remove germs, dirt, grease and oil from skin, sanitize skin, and condition the skin;</li><li>7) All purpose cleaning agents that remove dirt, oil, grease, and germs from the surfaces in areas such as kitchens, bathroom, and public facilities;</li><li>8) Disinfecting ingredients that kill or prevent growth of germs in a house or public facility;</li><li>9) Rug and Upholstery cleaning actives that lift and remove dirt and foreign particles from the surfaces and also deliver softening and perfumes;</li><li>10) Laundry softener actives that reduce static and makes fabric feel softer;</li><li>11) Laundry detergent ingredients that remove dirt, oil, grease, and stains and kill germs;</li><li>12) Dishwashing detergents that remove stains, food, germs;</li><li>13) Toilet bowl cleaning agents that remove stains, kill germs, and deodorize;</li><li>14) Laundry prespotter actives that help in removing stains from clothes;</li><li>15) Fabric sizing agents that enhance appearance of the fabric;</li><li>16) Vehicle cleaning actives that remove dirt, grease, etc. from vehicles and equipment;</li><li>17) Lubricating agents that reduce friction between parts; and</li><li>18) Textile products, such as dusting or disinfecting wipes.</li></ol>

0036In household care compositions, the rheology modifiers used in the present invention can be used either alone or may also-be used in combination with other known rheology modifiers including, but not limited to, polysaccharides (e.g., carrageenan, pectin, alginate), cellulose, ethers, biopolymers (e.g., xanthan gum), synthetic polymers, and abrasive/thickening silicas.

0037The above are only limited examples of personal care and household active ingredients and are not a complete list of active ingredients that can be used. Other ingredients that are used in these types of products are well known in the industry. In addition to the above ingredients conventionally used, the composition according to the present invention can optionally also include ingredients such as colorants, preservatives, antioxidants, nutritional supplements, activity enhancers, emulsifiers, viscosifying agents (such as salts, e.g., sodium chloride, ammonium chloride and potassium chloride), water-soluble polymers (e.g., HEC, modified HEC, carboxymethylcellulose), and fatty alcohols (e.g., cetyl alcohol), alcohols having 1-6 carbons, and fats and oils.

<u>PROTECTIVE COATINGS</u>

0038Water-based protective coating compositions (commonly referred to as paints) in which cellulose ether derivatives are commonly used include latex paints or dispersion paints, of which the principal ingredient is the film-forming - binders that include latices such as styrene-butadiene copolymers, vinyl acetate homopolymers and copolymers, and acrylic homopolymers and copolymers. Other binders that are typically used in paints include alkyd resins, and epoxy resins. Typically, paints also contain opacifying pigments, dispersing agents and water-soluble protective colloids, the proportions being, by weight of the total composition 10 parts to 50 parts of a latex, 10 parts to 50 parts of an opacifying pigment, 0.1 part to 2 parts of a dispersing agent, and 0.1 part to 2 parts of a water-soluble protective colloid. These protective coatings can be either aqueous based architectural or industrial coating compositions. Architectural coatings are intended for on-site application to interior or exterior surfaces of residential, commercial, institutional or industrial buildings. Industrial coatings are applied to factory-made articles before or after fabrication, usually with the aid of special techniques for application and drying.

0039Water-soluble polymers conventionally used in the manufacture of latex paints include casein, methyl cellulose, hydroxyethylcellulose (HEC), sodium carboxymethyl cellulose (CMC), polyvinyl alcohol, starch, and sodium polyacrylate. The HECs used in the present invention can be used as rheology modifiers for water-based protective coating compositions.

<u>PAPER COATINGS AND PAPER MAKING</u>

0040Paper coating is a process in which the surface structure of paper or board is improved by applying a mineral coating that is subsequently dried. Coating process is the application of a water-borne pigment slurry, which is bound at the surface by one of several binders. Other coating components can be added to obtain a suitable rheology, and to impart properties such as brightness or water resistance.

0041A coating process can generally be divided into three different phases: (1) preparation of the coating formulation (known as called coating color), (2) coating and (3) drying. The general principles of formulating paper coating are mostly well known. Moreover, each paper maker has his own tailor-made recipes for his specific requirements. Therefore, it would not be possible to give a "recipe" for a specific coating process, coating type or printing process. However, a generic coating formulation recipe contains 75 - 90 % pigment (such as clay, satin white, calcium carbonate, titanium dioxide, talc, aluminum hydroxide, calcium sulfate, barium sulfate, synthetics), 0.10 - 0.50 % dispersant, 0.05 - 0.30 % alkali, 5 - 20 % binders (such as styrene-butadiene latices, acrylics, polyvinyl acetate, starch and starch derivatives, proteins such as casein, soya) and 0 - 2 % co-binder (cellulose ethers, polyvinyl alcohol and solution or polyacrylates emulsion). Other functional additives such as lubricants, optical brightening agents and defoamers are often added to the coating formulation. All amounts of ingredients are based on weight of pigment. The HECs used in the present invention can be used as rheology modifiers for water-borne paper coating compositions.

0042In addition to paper coating, the blocky HECs used in the present invention can be used in papermaking process and for surface sizing. In papermaking process, the blocky HEC can be used as an additive in the stock as a refining agent, wet-strength agent, dry strength agent, internal bonding agent, water retention agent and improving the sheet formation. For surface sizing, the blocky HEC can be used as a binding agent and aiding in film formation.

<u>OILFIELD SERVICING FLUIDS</u>

0043Drilling an oil or gas well is a complex operation, involving several steps before and after the well is put into production. Primary oil-recovery operations include drilling the well, cementing the casing to the formation and completing the well prior to oil or gas production. Workover operations may be necessary during remedial work in producing wells, usually as an attempt to enhance or prolong the economic life of the well. When the flow rate of the fluid is diminished, the reservoir may be treated in some manner to increase the flow of fluid into the wellbore. This operation is called secondary recovery, known as fracturing/stimulation operations. They are performed either by acid wash or hydraulic fracturing. When the reservoir is depleted, enhanced oil recovery operations may be needed to increase the production rate. This operation is called tertiary recovery, and involves injection of fluids into the formation surrounding the production well to increase the flow rate of the formation fluid into the wellbore.

0044Drilling fluids are an integral element of the drilling program for primary oil recovery. They are especially designed to perform numerous functions that condition the success of drilling operations. Their principal functions include, but not limited to, are: <ul id="ul0001" list-style="bullet" compact="compact"><li>An effective hole cleaning efficiency (H.C.E.).</li><li>Maintaining the stability of the open hole-formation.</li><li>Formation of a thin and low-permeability filter cake on the formation.</li><li>Minimizing formation damage.</li><li>Friction reduction between the drilling string and the formation.</li><li>Cool and clean the drill bit.</li></ul>

0045To perform these functions, drilling fluids should possess particular properties with regard to rheology, density, and filtration control. Filtration control is a key performance attribute that affects all other properties. In fact, loss of significant amount of water from the drilling fluid into the formation would result in irreversible change of the overall drilling fluid properties (density and rheology) that would seriously affect the stability of the borehole.

0046Among a variety of additives, carboxymethyl cellulose (CMC), HEC and polyanionic cellulose (PAC) are widely used to optimize water-based drilling fluid properties. High-viscosity types are used for rheology and fluid loss control properties while low viscosity types are exclusively used for filtration control properties. In most cases, these types are used together in a drilling fluid composition. During drilling operations, optimum drilling fluid attributes are further achieved by combining different components including clay, CMC/PAC, xanthan gum (primary rheology modifier), starches (improved filtration control) and other synthetics polymers that may be required for dispersing or shale inhibition properties.

0047Completion and workover fluids are specialized fluids used during well completion operations and remedial workover procedures. They are placed across the chosen pay zone after the well has been drilled but prior to putting it on production. These fluids must control not only subsurface pressure with density, but also must minimize formation damage during completion and workover operations to improve oil or gas production rate. Because all wells are susceptible to formation damage to some degree (from a slight reduction in the production rate to complete plugging of specific zones) and the potential for permanent damage is greater during completion and workover operations than it is during drilling, it is imperative to use a fluid that causes the least possible damage to the pay zone formation. The principal functions of completion and workover fluids include, but not limited to, are: <ul id="ul0002" list-style="bullet" compact="compact"><li>Control subsurface pressures.</li><li>Minimize formation damage.</li><li>Maintain well bore stability.</li><li>Control fluid losses to the formation.</li><li>Transport solids.</li><li>Maintain stable fluid properties.</li></ul>

0048The types of completion and workoverfluids can be categorized into clear solids-free brines, polymer viscosified brines with bridging/weighting agents, and other fluids including oil base, water base, converted muds, foam, The primary selection criteria for an appropriate completion or workover fluid are density. Clear, solids free brines are the most commonly used fluids and are viscosified with polymers (CMC/PAC, xanthan gum, guar and guar derivatives, and HEC) and may incorporate solids that can be dissolved later, such as acid soluble calcium carbonate or sized sodium chloride salt, for increased density or bridging purposes. While HEC is the most suitable polymer for brine based systems, CMC/PAC and xanthan gum find their use in low density (up to 12 ppg) monovalent salts based brines.

0049Hydraulic fracturing may be defined as the process in which fluid pressure is applied to the exposed reservoir rock until failure or fracturing occurs. After failure of the rock, a sustained application of fluid pressure extends the fracture outward from the point of failure. This may connect existing natural fractures as well as provide additional drainage area from the reservoir. The fluid used to transmit the hydraulic pressure to the reservoir rock is called the fracturing fluid. To prevent the fracture from closing when pumping is stopped, propping agents, such as sized sand, are added to the fracturing fluid. The propping agent acts as supports to hold the fracture open after the treatment and to provide an improved ability of the fracture to conduct oil or gas through the fracture to the wellbore.

0050The blocky HECs used in the present invention can be used as rheology modifiers for aqueous based oilfield servicing fluids with improved efficiency.

<u>CIVIL ENGINEERING SERVICING FLUIDS</u>

0051Civil engineering applications include tunneling, diaphragm walling, pilling, trenching, horizontal drilling, and water-well drilling. These applications are often characterized by their closeness to agglomerations where strict environmental regulation is in effect to minimize any kind of pollution or contamination. The corresponding working sites are further characterized by the availability of very poor mixing equipment on-site to efficiently disperse and dissolve the water-soluble polymers (WSPs). There is a desire in civil engineering applications for polymer suspensions that are stable, environmentally friendly, and meet all discharge regulations.

0052The blocky HECs used in the present invention are used as rheology modifiers in fluids for civil engineering applications including tunneling, piling, diaphragm walling, drilling, and bentonite doping.

<u>CONSTRUCTION / BUILDING COMPOSITIONS</u>

0053Building compositions, also known as construction materials, include concrete, tile cement and adhesives, projection plasters, stuccos based on cement and synthetic binders, ready mixed mortars, manually applied mortars, underwater concrete, joint cement, joint compounds, gypsum board, crack fillers, floor screeds, and adhesive mortars. These compositions are essentially Portland cements, Plaster of Paris or vinyl copolymers containing functional additives to impart characteristics required for various construction applications. The joint cement can contain clay and mica or can be clay free (i.e., contain less than 0.5 wt % clay). While lime was once the preferred material for controlling the water ratio in the building compositions, cellulose ethers are at present time the most used because of their contribution to improve the water retention characteristics and other physical properties such as workability, consistency, open time, tack, bleeding, adhesion, set time, and air entrainment.

0054The blocky HECs used in the present invention are used as rheology modifiers in the above mentioned construction and building material compositions.

<u>PHARMACEUTICALS</u>

0055Pharmaceutical compositions normally are in the form of tablets, capsules, or granules. The sole purpose of a pharmaceutical composition, regardless of its form, is to deliver a therapeutically active medicament to the desired place of use. The most common form of the medicament delivery system is the tablet form. In the tablet or capsule form, it is common practice to use at least one inert ingredient for production, delivery, and economic considerations. Examples of inert ingredients are excipients, diluents, fillers, and binders. The combination of the medicament with the inert ingredients provides a formulation that can be directly compressed into tablets or made into granules or agglomerations for encapsulation. In order to provide a directly compressible product, these excipients must have certain physical properties, including flow ability, sufficient particle size distribution, binding ability, acceptable bulk and tap densities, and acceptable dissolution properties in order to release the medicament upon oral administration.

0056The blocky HECs used in the present invention can be used in free flowing, directly compressible slow release granule compositions that can be prepared by dry-blending, roller-compaction, or wet-agglomeration for use as a pharmaceutical excipient. This excipient contains from 5 to 80 % by weight of the blocky HEC. This excipient can also contain an inert pharmaceutical filler in the amount of from 0.01 to 95 % by weight. Examples of the pharmaceutical fillers are monosaccharides, disaccharides, polysaccharides, polyhydric alcohols, inorganic compounds, and mixtures thereof. This excipient composition can also contain from 0.01 to 50 % of an additional control release agent such as cellulose ethers, cellulose esters, polyethylene oxides, polyvinyl alcohol and copolymers, methacrylic acid derivatives, waxy-fatty materials, natural hydrocolloids, and Carbopol^® derivatives.

0057In accordance with the present invention, a control release pharmaceutical tablet for oral administration is composed of from 5 to 80 % by weight of the total composition of the blocky HEC, up to 90 % by weight of an inert pharmaceutical filler (as mentioned above), and an effective amount of a therapeutically active medicament to render a therapeutic effect. The ratio of medicament to the blocky HEC (hydrophilic material) is based in part upon the relative solubility of the medicament and the desired rate of release. By varying this ratio and / or the total weight of the tablet, one can achieve different slow release profiles, and may extend the dissolution of some medicaments to about 24 hours.

0058An immediate release tablet composition of the present invention is composed of from 0.5 to 10 % by weight of the blocky HEC, suitable fillers and tableting aids, and an effective amount of a therapeutically active medicament. The amount of the active medicament depends on the desired amount needed to deliver the desired effect.

EXAMPLES

0059The following Examples indicate various possible methods for making, describing, and using the HECs used in the present invention. These Examples are merely illustrative, and are not to be construed as limiting the present invention to composition containing particular compounds, or or particular processes. All parts and percentages are by weight unless otherwise stated.

0060The following processes are used to prepare the Examples and Comparative Examples that are designated in the various Tables. Table 1 shows the description of the individual Examples.

PROCEDURES FOR PREPARING SAMPLES:

<u>Process A</u>

0061Cellulose, water, and solvents were charged to a nitrogen-sparged, high pressure reaction kettle per the ratios described in the various tables. The reactor was inerted with nitrogen and pressure tested. The caustic was added and the alkali cellulose slurry temperature was maintained at 20° C for approximately 1 hour. Ethylene oxide was added and the temperature was raised to 45° C and maintained for 45 minutes. The temperature was then raised to 100° C and held for 60 minutes to complete the reaction. The reaction mixture was cooled down to ambient temperature and neutralized with sufficient acid. The product was then purified and ground to the desired particle size.

<u>Process B</u>

0062Cellulose, water, and solvent were charged to a nitrogen-sparged, high pressure reaction kettle per the ratios described in the various tables. The reactor was inerted and pressure tested. The caustic was added and the alkali cellulose slurry temperature was maintained at 20° C for approximately 1 hour. Ethylene oxide was added to the reaction mixture. The reactor was heated to 30° C. Acid was added continuously during a 30 minute heat-up to and 30 minute hold at 60° C to reach the desired alkali cellulose ratio (AC2). The temperature was then raised to 100° C and held for 60 minutes to complete the reaction. The reaction mixture was cooled down to ambient temperature and neutralized with sufficient amount of acid to neutralize any excess alkali. The product was then purified, dried, and ground to the desired particle size.

<u>Process C</u>

0063Cellulose, water, and solvent were charged to a nitrogen-sparged, high pressure reaction kettle per the ratios described in the various tables. The reactor was inerted with nitrogen and pressure tested. The caustic was added and the alkali cellulose slurry temperature was maintained at 20° C for approximately 1 hour. Acid was added to reach the desired alkali cellulose ratio (AC2). Ethylene oxide was added to the reaction mixture. The reaction mixture was heated to 60° C over 40 minutes and held at that temperature for 30 minutes. The temperature was then raised to 100° C for 60 minutes to complete the reaction. The reaction mixture was cooled down to ambient temperature and neutralized with sufficient acid to neutralize any excess alkali. The product was then purified dried, and ground to the desired particle size.

<u>Process D</u>

(Reference Process)

0064Cellulose, water, and solvent were charged to a nitrogen-sparged, high pressure reaction kettle per the ratios described in the various tables. The reactor was inerted with nitrogen and pressure tested. The caustic was added and the alkali cellulose slurry temperature was maintained at 20° C for approximately 1 hour. Ethylene oxide was added to the reaction mixture. The reactor was heated to 30° C. Acid was added continuously during a 30 minute heat-up to and 30 minute hold at 60° C in order to reach the desired alkali cellulose ratio (AC2). The temperature was raised to 100° C and held for 60 minutes. The reactor was then cooled to 50° C. Acid or caustic was added to achieve the desired caustic/cellulose ratio for the hydrophobe reaction (ACHM). The hydrophobe was charged to the reaction mixture. The reactor was heated to 115° C and maintained for 2.5 hours. The reactor was then cooled to 25° C to charge the anionic and/or cationic reagents. The reactor was reheated to 60° C and the temperature was maintained for 2.5 hours. The reaction mixture was cooled down to ambient temperature and neutralized with sufficient acid to neutralize any excess alkali. The product was then purified, dried, and ground to the desired particle size.

<u>Process E</u>

(Reference Process)

0065Cellulose, water, and solvent were charged to a nitrogen-sparged, high pressure reaction kettle per the ratios described in the various tables. The reactor was inerted with nitrogen and pressure tested. The caustic was added and the alkali cellulose slurry temperature was maintained at 20° C for approximately 1 hour. Acid was added to reach the desired alkali cellulose ratio (AC2). The hydrophobe was added to the reactor and mixed. Ethylene oxide was added to the reaction mixture. The reactor was heated to 60° C over 40 minutes and held at that temperature for 60 minutes. The temperature was then raised to 115° C and maintained for 90 minutes to complete the reaction. The reactor was then cooled to 40° C for charging the anionic and/or cationic reagents and any added EO for improving biostability. The reactor was heated to 60° C and held for 60 minutes. The reaction mixture was cooled down to ambient temperature and neutralized with sufficient acid to neutralize any excess alkali. The product was then purified, dried, and ground to the desired particle size.

<u>Process F</u>

0066Cellulose, water, and solvents are charged to a nitrogen-sparged, high pressure reaction kettle per the ratios described in the various tables. The reactor is inerted and pressure tested. The caustic is added and the alkali cellulose slurry temperature is maintained at 20 C for approximately 1 hour. Ethylene oxide was added and the temperature was raised to 45° C and maintained for 45 minutes. The temperature was then raised to 100° C and held for 60 minutes to complete the reaction. The slurry is cooled down then, a second amount of caustic is added (AC2) and a second alkali cellulose period of 45 minutes at 20°C is maintained. EO and hydrophobe (if specified) are added then and the temperature is raised to 115°C and maintained for 2.5 hours. The reaction mixture is cooled down to ambient temperature and neutralized with sufficient acid. The product is then purified, dried, and ground to the desired particle size. <tables id="tabl0001" num="0001"><table frame="all"><title>Table 1: Sample Preparation Descriptions</title><tgroup cols="13"><colspec colnum="1" colname="col1" colwidth="24mm" /><colspec colnum="2" colname="col2" colwidth="19mm" /><colspec colnum="3" colname="col3" colwidth="13mm" /><colspec colnum="4" colname="col4" colwidth="21mm" /><colspec colnum="5" colname="col5" colwidth="33mm" /><colspec colnum="6" colname="col6" colwidth="14mm" /><colspec colnum="7" colname="col7" colwidth="15mm" /><colspec colnum="8" colname="col8" colwidth="15mm" /><colspec colnum="9" colname="col9" colwidth="16mm" /><colspec colnum="10" colname="col10" colwidth="18mm" /><colspec colnum="11" colname="col11" colwidth="23mm" /><colspec colnum="12" colname="col12" colwidth="18mm" /><colspec colnum="13" colname="col13" colwidth="17mm" /><thead><row><entry align="center" valign="top">Example</entry><entry align="center" valign="top">Cellulose Fumish^A</entry><entry align="center" valign="top">Cell Bone Dry (g)</entry><entry align="center" valign="top">Solvent (g)⁸</entry><entry align="center" valign="top">Acid Type and Concentration</entry><entry align="center" valign="top">H₂O: AGU^c</entry><entry align="center" valign="top">NaOH: AGU^D AC1</entry><entry align="center" valign="top">NaOH: AGU AC2</entry><entry align="center" valign="top">NaOH: AGU ACHM</entry><entry align="center" valign="top">EO(g) .</entry><entry align="center" valign="top">HM^E (g)</entry><entry align="center" valign="top">Cationic or Anionic Agent</entry><entry align="center" valign="top">Process</entry></row></thead><tbody><row><entry align="center">1 Blocky</entry><entry align="center">I</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">20% acetic in IPA</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.22</entry><entry align="center">-</entry><entry align="center">57.0</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">B</entry></row><row><entry align="center">2 Blocky*</entry><entry align="center">I</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">20% acetic in IPA</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.09</entry><entry align="center">-</entry><entry align="center">55.0</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">B</entry></row><row><entry align="center">3'Blocky</entry><entry align="center">Ii</entry><entry align="center">58</entry><entry align="center">TBA 668 IPA 17.3 Acetone 10.4</entry><entry align="center">70% nitric</entry><entry align="center">12.6</entry><entry align="center">1.74</entry><entry align="center">1.01</entry><entry align="center">-</entry><entry align="center">36.1</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">C</entry></row><row><entry align="center">4 Blocky*</entry><entry align="center">I</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">27.5% acetic in IPA</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">0.81</entry><entry align="center">-</entry><entry align="center">42.3</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">B</entry></row><row><entry align="center">Comparative 4C</entry><entry align="center">I</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">35% acetic in IPA</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">0.41</entry><entry align="center">-</entry><entry align="center">42.2</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">B</entry></row><row><entry align="center">5 Blocky</entry><entry align="center">I</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">20% acetic in IPA</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.09</entry><entry align="center">-</entry><entry align="center">55.4</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">B</entry></row><row><entry align="center">Comparative 5C</entry><entry align="center">I</entry><entry align="center">100</entry><entry align="center">TBA 898 IPA 81 Acetone 29</entry><entry align="center">65% nitric</entry><entry align="center">17.6</entry><entry align="center">1.30</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">71.6</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">A</entry></row><row><entry align="center">6 Blocky CMHMHEC (C16)*</entry><entry align="center">Ii</entry><entry align="center">58</entry><entry align="center">IPA 664</entry><entry align="center">20% acetic in IPA (AC2) 50% acetic in IPA (ACHM)</entry><entry align="center">17.1</entry><entry align="center">1.74</entry><entry align="center">1.22</entry><entry align="center">0.73</entry><entry align="center">44.9</entry><entry align="center">Hexadecyl GE^F 23.4</entry><entry align="center">SCA^G. 16</entry><entry align="center">D</entry></row><row><entry align="center">7 Blocky CMHMHEC (C16)*</entry><entry align="center">Ii</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">20% acetic in IPA (AC2) 50% acetic in IPA (ACHM)</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.09</entry><entry align="center">0.49</entry><entry align="center">58.1</entry><entry align="center">Hexadecyl GE 35.1</entry><entry align="center">SCA 20</entry><entry align="center">D</entry></row><row><entry align="center">8 Blocky HMHEC (C4)*</entry><entry align="center">I</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">20% acetic in IPA (AC2) 50% acetic in IPA (ACHM)</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.09</entry><entry align="center">0.24</entry><entry align="center">55.8</entry><entry align="center">Butyl GE 12.2</entry><entry align="center">-</entry><entry align="center">D</entry></row><row><entry align="center">9 Blocky HMHEC (C12)*</entry><entry align="center">iv</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">20% acetic in IPA</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.09</entry><entry align="center">1.09</entry><entry align="center">61.9</entry><entry align="center">Dodecyl Bromide 23.9</entry><entry align="center">-</entry><entry align="center">D</entry></row><row><entry align="center">10 Blocky HMHEC (C10)*</entry><entry align="center">iv</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">20% acetic in IPA</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.09</entry><entry align="center">1.09</entry><entry align="center">61.9</entry><entry align="center">Decyl Bromide 23.7</entry><entry align="center">-</entry><entry align="center">D</entry></row><row><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center" /></row><row><entry align="center">11 Blocky HMHEC (C4/C16)*</entry><entry align="center">iv</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">20% acetic in IPA (AC2) 50% acetic in IPA (ACHM)</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.09</entry><entry align="center">0.24</entry><entry align="center">50.0</entry><entry align="center">Hexadecyl GE 6.7 Butyl GE 24.4</entry><entry align="center" /><entry align="center">D</entry></row><row><entry align="center">12 Blocky catHMHEC (C16)*</entry><entry align="center">iv</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">20% acetic in IPA (AC2) 50% acetic in IPA (ACHM)</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.09</entry><entry align="center">0.24</entry><entry align="center">61.9</entry><entry align="center">Hexadecyl GE 6.7</entry><entry align="center">60 % Quat 188^H 5.94</entry><entry align="center">D</entry></row><row><entry align="center">13 Blocky</entry><entry align="center">ii</entry><entry align="center">100</entry><entry align="center">TBA 859 IPA 77 Acetone 28</entry><entry align="center">65% nitric</entry><entry align="center">15.8</entry><entry align="center">1.74</entry><entry align="center">1.22</entry><entry align="center">-</entry><entry align="center">103.3</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">C</entry></row><row><entry align="center">14 Blocky</entry><entry align="center">I</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">12.5% acetic in IPA</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.34</entry><entry align="center">-</entry><entry align="center">83.7</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">B</entry></row><row><entry align="center">15 Blocky</entry><entry align="center">ii</entry><entry align="center">58</entry><entry align="center">TBA 668 IPA 17.3 Acetone 10.4</entry><entry align="center">70% nitric</entry><entry align="center">12.6</entry><entry align="center">1.74</entry><entry align="center">1.01</entry><entry align="center">-</entry><entry align="center">63.3</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">C</entry></row><row><entry align="center">16 Blocky,</entry><entry align="center">ii</entry><entry align="center">58</entry><entry align="center">TBA 668 IPA 17.3 Acetone 10.4</entry><entry align="center">70% nitric</entry><entry align="center">12.6</entry><entry align="center">1.74</entry><entry align="center">0.81</entry><entry align="center">-</entry><entry align="center">53.0</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">C</entry></row><row><entry align="center">17 Blocky</entry><entry align="center">Ii</entry><entry align="center">58</entry><entry align="center">TBA 668 IPA.17.3 Acetone 10.4</entry><entry align="center">70% nitric</entry><entry align="center">12.6</entry><entry align="center">1.74</entry><entry align="center">0.61</entry><entry align="center">-</entry><entry align="center">53.0</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">C</entry></row><row><entry align="center">Comparative 17C</entry><entry align="center">ii</entry><entry align="center">58</entry><entry align="center">TBA 668 IPA 17.3 Acetone 10.4</entry><entry align="center">70% nitric</entry><entry align="center">12.6</entry><entry align="center">1.74</entry><entry align="center">0.41</entry><entry align="center">-</entry><entry align="center">53.0</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">C</entry></row><row><entry align="center">18 Blocky</entry><entry align="center">v</entry><entry align="center">100</entry><entry align="center">TBA 898 IPA 81 Acetone 29</entry><entry align="center">65% nitric</entry><entry align="center">15.1</entry><entry align="center">0.22</entry><entry align="center">1.30</entry><entry align="center">-</entry><entry align="center"><maths id="math0001" num=""><img file="EP1858970B2_D0002.tif" /></maths></entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">F</entry></row><row><entry align="center">19 Blocky</entry><entry align="center">I</entry><entry align="center">58</entry><entry align="center">IPA 667</entry><entry align="center">100% acetic</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.74</entry><entry align="center">-</entry><entry align="center">120.4</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">B</entry></row><row><entry align="center">Comparative 19C</entry><entry align="center">I</entry><entry align="center">100</entry><entry align="center">TBA 898 IPA 81 Acetone 29</entry><entry align="center">65% nitric</entry><entry align="center">17.6</entry><entry align="center">1.30</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">136.9</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">A</entry></row><row><entry align="center">20 Blocky CMHMHEC (C16)*</entry><entry align="center">iii</entry><entry align="center">58</entry><entry align="center">TBA 659 IPA 17.2 Acetone 10.3</entry><entry align="center">20% acetic in IPA (AC2) 50% acetic in IPA (ACHM)</entry><entry align="center">13.5</entry><entry align="center">1.74</entry><entry align="center">1.22</entry><entry align="center">0.73</entry><entry align="center">56.0</entry><entry align="center">Hexadecyl GE 49</entry><entry align="center">SCA 16</entry><entry align="center">D</entry></row><row><entry align="center">21 Blocky CMHMHEC (C16)*</entry><entry align="center">ii</entry><entry align="center">58</entry><entry align="center">TBA 663 IPA 17.2 Acetone 10.3</entry><entry align="center">20% acetic in IPA (AC2) 50% acetic in IPA (ACHM)</entry><entry align="center">13.5</entry><entry align="center">1.74</entry><entry align="center">1.22</entry><entry align="center">0.73</entry><entry align="center">56.1</entry><entry align="center">Hexadecyl GE 49</entry><entry align="center">SCA 16</entry><entry align="center">D</entry></row><row><entry align="center">22 Blocky CMHMHEC (C16)*</entry><entry align="center">iii</entry><entry align="center">58</entry><entry align="center">TBA 678 IPA 17.6 Acetone 10.5</entry><entry align="center">85% phosphoric</entry><entry align="center">10.8</entry><entry align="center">1.82</entry><entry align="center">1.09</entry><entry align="center">-</entry><entry align="center"><maths id="math0002" num=""><img file="EP1858970B2_D0003.tif" /></maths></entry><entry align="center">Cetyl Bromide 6.5</entry><entry align="center">MCA¹ 20</entry><entry align="center">E</entry></row><row><entry align="center">23 Blocky CMHMHEC C16*</entry><entry align="center">iii</entry><entry align="center">58</entry><entry align="center">TBA 646 IPA 16.7 Acetone 10.0</entry><entry align="center">85% phosphoric</entry><entry align="center">16.2</entry><entry align="center">1.82</entry><entry align="center">1.09</entry><entry align="center">-</entry><entry align="center"><maths id="math0003" num=""><img file="EP1858970B2_D0004.tif" /></maths></entry><entry align="center">Cetyl Bromide 8.7</entry><entry align="center">MCA 20</entry><entry align="center">E</entry></row><row><entry align="center">24 Blocky</entry><entry align="center">I</entry><entry align="center">500</entry><entry align="center">TBA 5119 IPA 460 Acetone 167</entry><entry align="center">20% nitric</entry><entry align="center">16.7</entry><entry align="center">1.74</entry><entry align="center">1.09</entry><entry align="center">-</entry><entry align="center">685</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">C</entry></row><row><entry align="center">Comparative 24C</entry><entry align="center">ii</entry><entry align="center">100</entry><entry align="center">TBA 850 IPA 76 Acetone 28</entry><entry align="center">65% nitric</entry><entry align="center">17.6</entry><entry align="center">1.30</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">144.6</entry><entry align="center">-</entry><entry align="center">-</entry><entry align="center">A</entry></row><row><entry align="center">25 Blocky CMHMHEC (C16)*</entry><entry align="center">iii</entry><entry align="center">58</entry><entry align="center">TBA 662 IPA 16.7 Acetone 10.3</entry><entry align="center">85% phosphoric</entry><entry align="center">13.5</entry><entry align="center">1.82</entry><entry align="center">1.09</entry><entry align="center">-</entry><entry align="center"><maths id="math0004" num=""><img file="EP1858970B2_D0005.tif" /></maths></entry><entry align="center">Cetyl Bromide 8.7</entry><entry align="center">MCA 20</entry><entry align="center">E</entry></row><row><entry align="center">26 Blocky CMHMHEC*</entry><entry align="center">ii</entry><entry align="center">58</entry><entry align="center">TBA 662 IPA 16.7 Acetone 10.3</entry><entry align="center">85% phosphoric</entry><entry align="center">21.6</entry><entry align="center">1.82</entry><entry align="center">1.09</entry><entry align="center">0.49</entry><entry align="center"><maths id="math0005" num=""><img file="EP1858970B2_D0006.tif" /></maths></entry><entry align="center">Cetyl Bromide 6.5</entry><entry align="center">MCA 20</entry><entry align="center">E</entry></row><row><entry align="center">Example</entry><entry align="center">Cellulose Fumish^A</entry><entry align="center">Cell Bone Dry (g)</entry><entry align="center">Solvent (g)⁸</entry><entry align="center">Acid Type and Concentration</entry><entry align="center">H₂O: AGU^c</entry><entry align="center">NaOH: AGU^D AC1</entry><entry align="center">NaOH: AGU AC2</entry><entry align="center">NaOH: AGU ACHM</entry><entry align="center">EO(g).</entry><entry align="center">HM^E (g)</entry><entry align="center">Cationic or Anionic Agent</entry><entry align="center">Process</entry></row><row><entry align="center">25 Blocky CMHMHEC (C16)*</entry><entry align="center">ii</entry><entry align="center">100</entry><entry align="center">TBA 850 IPA 76 Acetone 28</entry><entry align="center">65% nitric</entry><entry align="center">15.1</entry><entry align="center">0.22</entry><entry align="center">1.30</entry><entry align="center">-</entry><entry align="center"><maths id="math0006" num=""><img file="EP1858970B2_D0007.tif" /></maths></entry><entry align="center">Hexadecyl GE 20.7</entry><entry align="center">-</entry><entry align="center">F</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">A_I Cotton Linter, Intrins c Viscosity I.V.(dl/g) > 20</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">ii Wood Pulp, I.V.(dl/g) 4 - 8</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">iii Wood Pulp, I.V.(dl/g) 9 - 12</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">iv Wood Pulp, I.V.(dl/g) > 18</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">^BThe solvent weight includes the solvent delivered to the reactor during the acid quench (total solvent). IPA=isopropanol TBA=Tertiary Butyl alcohol</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">^CMolar ratio of water to anhydroglucose (AGU)</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">^DMolar ratio of sodium hydroxide (NaOH) to anhydroglucose (AGU)</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">^EHydrophobe modification (HM)</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">^FGE=Glycidal Ether</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">^GSCA=Sodium MonoChloroacetate.</entry></row><row rowsep="0"><entry namest="col1" nameend="col13" align="left">^HQuat 188=cationizing agent - N-(3-chloro-2-hydroxypropyl)trimethylammonium chloride</entry></row><row><entry namest="col1" nameend="col13" align="left">^IMCA=Mono Chloroacetic Acid</entry></row></tbody></tgroup><tgroup cols="13" rowsep="0"><colspec colnum="1" colname="col1" colwidth="24mm" /><colspec colnum="2" colname="col2" colwidth="19mm" /><colspec colnum="3" colname="col3" colwidth="13mm" /><colspec colnum="4" colname="col4" colwidth="21mm" /><colspec colnum="5" colname="col5" colwidth="33mm" /><colspec colnum="6" colname="col6" colwidth="14mm" /><colspec colnum="7" colname="col7" colwidth="15mm" /><colspec colnum="8" colname="col8" colwidth="15mm" /><colspec colnum="9" colname="col9" colwidth="16mm" /><colspec colnum="10" colname="col10" colwidth="18mm" /><colspec colnum="11" colname="col11" colwidth="23mm" /><colspec colnum="12" colname="col12" colwidth="18mm" /><colspec colnum="13" colname="col13" colwidth="17mm" /><tbody><row><entry namest="col1" nameend="col13" align="justify">* Reference example</entry></row></tbody></tgroup></table></tables>

Examples 1-5

0067The properties for HECs of Examples 1 - 5 of this invention that have an HE-MS between 1 and 2 are shown in Table 2. Table 1 describes how the non-uniformly substituted HECs are prepared by completely opening up the cellulose fiber with high initial caustic level (AC1) and then "quenching" to an intermediate caustic level (AC2). This process creates regions not accessible to the reactants. Examples 1-5 in Table 2 have an unsubstituted trimer ratio (U3R) greater than 0.21 indicative of a non-uniform structure. Furthermore, the fiber rating for these blocky HECs is low (less than 6) indicating that the reaction is homogeneous on a macroscopic level instead of heterogeneous as for example, a mixture of highly substituted HEC and unsubstituted cellulose fibers would appear. The fiber rating is determined by comparing the 1 wt% HEC solutions to cellulose fiber solution standards that have been prepared with cut cotton linters. The ratings 1, 2, 3, 4, 5, and 6 correspond to 0.4, 1.4, 3.2, 6.9, 11.4, 16 ppm fiber concentration, respectively.

0068HECs that have good solution properties and unsubstituted trimer ratios greater than 0.21 are the basis of this invention. Comparative Examples 4C and 5C as well as several commercial samples with HE-MS between 1 and 2 have a U3R well below 0.21 indicating a more uniform substitution along the polymer backbone.

0069In addition, it has been found that the second caustic to AGU molar ratio (AC2) should be greater than about 0.6 to induce a blocky structure with good solution properties. Example 4 and Comparative Example 4C show a dramatic change in the structure as the second caustic to AGU molar ratio is reduced from 0.8 to 0.4. The unsubstituted trimer ratio drops significantly from 0.30 to 0.16. Furthermore, the viscosity of the solution drops from 21,800 cPs to 10,100 cP indicating a less associative structure consistent with a more uniform distribution as measured by the low unsubstituted trimer ratio.

0070Examples 1, 2, 4, and 5 show that high molecular weight blocky HECs produced from cotton linters have 1 wt %.Brookfield viscosities (spindle 3, 3,rpm, at 25° C) up to 25,000 cps. Commercially available high molecular weight HECs such as those marketed under the trademarks Natrosol 250 HHBR &amp; HHR, Cellosize QP 100 MH, and Tylose H 200000 YP2 products typically have 1 wt% viscosities in the range of 4,500 - 6,000 cP. Furthermore, the HEC solutions used in the present invention have elasticities (G's) an order of magnitude greater than commercially available high molecular weight HEC (see Table 2 and 3).

0071Example 3 is a blocky HEC produced from a low molecular weight wood pulp starting material. The synthesis procedure was performed on a wide range of furnishes from cotton linters to wood pulps in order to generate a family of blocky HEC products. <tables id="tabl0002" num="0002"><table frame="all"><title>Table 2 - HEC with HE-MS 1 - 2</title><tgroup cols="6"><colspec colnum="1" colname="col1" colwidth="46mm" /><colspec colnum="2" colname="col2" colwidth="11mm" /><colspec colnum="3" colname="col3" colwidth="33mm" /><colspec colnum="4" colname="col4" colwidth="16mm" /><colspec colnum="5" colname="col5" colwidth="16mm" /><colspec colnum="6" colname="col6" colwidth="46mm" /><thead><row><entry valign="top">Example</entry><entry valign="top">HE-MS</entry><entry valign="top">1% Aq. Viscosity (cP)</entry><entry valign="top">G' at 0.1 Hz</entry><entry valign="top">Fiber Count</entry><entry valign="top">Unsubstituted Trimer Ratio U3R</entry></row></thead><tbody><row><entry>1 Blocky HEC</entry><entry>1.4</entry><entry>18,600</entry><entry>5.6</entry><entry>3</entry><entry>0.279</entry></row><row><entry>2 Blocky HEC*</entry><entry>1.3</entry><entry>25,000</entry><entry>8.1</entry><entry>2</entry><entry>0.382</entry></row><row><entry>3 Blocky HEC</entry><entry>1.8</entry><entry>191 ^@ 2 wt%</entry><entry /><entry>1</entry><entry>0.464</entry></row><row><entry>4 Blocky HEC*</entry><entry>1.3</entry><entry>21,800</entry><entry /><entry>3</entry><entry>0.301</entry></row><row><entry>Comparative 4C</entry><entry>1.3</entry><entry>10,100</entry><entry /><entry>1</entry><entry>0.157</entry></row><row><entry>5 Blocky HEC</entry><entry>1.7</entry><entry>14,400</entry><entry /><entry>1</entry><entry>0.218</entry></row><row><entry>Comparative 5C</entry><entry>1.6</entry><entry>1,860</entry><entry /><entry>1</entry><entry>0.131</entry></row><row><entry>Comparative Natrosol 150GXR</entry><entry>1.5</entry><entry>200 @ 2 wt%</entry><entry /><entry>1</entry><entry>0.191</entry></row><row><entry>Comparative Natrosol 150GBXR</entry><entry>1.6</entry><entry>185 @ 2 wt%</entry><entry /><entry>1</entry><entry>0.031</entry></row><row><entry>Comparative Natrosol 180GXR</entry><entry>1.8</entry><entry>325 @ 2 wt%</entry><entry /><entry>1</entry><entry>0.167</entry></row><row><entry>Comparative Cellosize QP30000H</entry><entry>1.9</entry><entry>1,800</entry><entry /><entry>1</entry><entry>0.196</entry></row><row><entry>Comparative Cellosize EP 09</entry><entry>2.0</entry><entry>100 @ 5 wt%</entry><entry /><entry>1</entry><entry>0.167</entry></row></tbody></tgroup><tgroup cols="6" rowsep="0"><colspec colnum="1" colname="col1" colwidth="46mm" /><colspec colnum="2" colname="col2" colwidth="11mm" /><colspec colnum="3" colname="col3" colwidth="33mm" /><colspec colnum="4" colname="col4" colwidth="16mm" /><colspec colnum="5" colname="col5" colwidth="16mm" /><colspec colnum="6" colname="col6" colwidth="46mm" /><tbody><row><entry namest="col1" nameend="col6" align="justify">* Reference examples</entry></row></tbody></tgroup></table></tables>

Examples 6-12

(Reference Examples)

0072Blocky HECs provide a unique template for further derivatization with hydrophobe, cationizing reagents, anionizing reagents, cross-linkers, and polyethylene oxide chain extenders. As shown in Table 2a, Examples 6-12 are various derivatives of blocky HECs with HE-MS between 1 and 2. Examples 6 and 7 contain cetyl hydrophobe and carboxymethyl modification. Example 8 and 10 describe hydrophobe-modified blocky HECs with U3Rs of 0.45 and 0.255, respectively. Examples of blocky HECs with C₁₂, C₁₀, and mixed C₄/C₁₆ hydrophobes, and with a cationic charge are shown in Table 2a as examples 9-12. All of these derivatized blocky HEC samples have a low fiber rating. <tables id="tabl0003" num="0003"><table frame="all"><title>Table 2a - Derivatized HEC with HE-MS 1-2</title><tgroup cols="7"><colspec colnum="1" colname="col1" colwidth="36mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="15mm" /><colspec colnum="4" colname="col4" colwidth="19mm" /><colspec colnum="5" colname="col5" colwidth="25mm" /><colspec colnum="6" colname="col6" colwidth="17mm" /><colspec colnum="7" colname="col7" colwidth="40mm" /><thead><row><entry valign="top">Example</entry><entry valign="top">HE-MS</entry><entry valign="top">HM (%)</entry><entry valign="top">Charge (DS)</entry><entry valign="top">1% Aq. Viscosity (cP)</entry><entry valign="top">Fiber Count</entry><entry valign="top">Unsubstituted Trimer Ratio U3R</entry></row></thead><tbody><row><entry>6 Blocky CMHMHEC (C16)</entry><entry>1.3</entry><entry>0.21</entry><entry>0.25</entry><entry>13</entry><entry>1</entry><entry>N/A</entry></row><row><entry>7 Blocky CMHMHEC (C16)</entry><entry>1.7</entry><entry>1.2</entry><entry>0.17</entry><entry>210</entry><entry>1</entry><entry>N/A</entry></row><row><entry>8 Blocky HMHEC (C4)</entry><entry>1.5</entry><entry>2.6</entry><entry>-</entry><entry>13,460</entry><entry>3</entry><entry>0.450</entry></row><row><entry>9 Blocky HMHEC (C12)</entry><entry>1.8</entry><entry>1.4</entry><entry>-</entry><entry>28,400</entry><entry>2</entry><entry>Not measured</entry></row><row><entry>10 Blocky HMHEC (C10)</entry><entry>1.7</entry><entry>1.8</entry><entry>-</entry><entry>15,800</entry><entry>2</entry><entry>0.255</entry></row><row><entry>11 Blocky HMHEC (C4/C16)</entry><entry>1.4</entry><entry>0.8/0.3</entry><entry>-</entry><entry>29,540</entry><entry>1</entry><entry>Not measured</entry></row><row><entry>12 Blocky cat HMHEC (C16)</entry><entry>1.7</entry><entry>0.5</entry><entry>0.01</entry><entry>40,0000</entry><entry>1</entry><entry>0.380</entry></row></tbody></tgroup></table></tables>

Examples 13-19

0073The most common commercial HECs have an HE-MS in the range of 2 to 3. Table 3 shows that blocky HECs can be produced in this HE-MS range. For comparison, all commercial and Comparative Examples have a U3R less than 0.21 indicating a more uniform structure.

0074Example 14 shows that high molecular weight blocky HEC with an HE-MS of 2.3 exhibits a significantly higher viscosity than commercially available HEC in the same HE-MS range.

0075As is the case for HECs in the HE-MS range of 1 - 2, the second caustic to AGU molar ratio (AC2) should be greater than about 0.6 to induce blocky HECs that form good solutions with low fiber rating in the HE-MS range of 2 - 3. Example 17 and Comparative Example 17C demonstrate a dramatic change in the structure as the second caustic level is reduced from 0.6 to 0.4 mole NaOH/mole AGU. The unsubstituted trimer ratio drops significantly from 0.31 to 0.10. Furthermore, the fiber content of Comparative Example 17C increases.

0076Another process that produces the blocky structure is demonstrated in Example 18. In this case, an ethylene oxide reaction at extremely low caustic level (AC1 0.22 mole NaOH/mole AGU) was used to partially open up the cellulose fiber before reacting additional ethylene oxide at an AC2 of 1.3 mole NaOH/mole AGU. The U3R of this Example is 0.40 indicating that it is a HEC with a blocky structure.

0077In Example 19, the reaction takes place at a single, very high caustic to AGU molar ratio. Although this process is disclosed in this Example, it is not preferred because of the poor reaction efficiencies. Notwithstanding, it still produced an extremely blocky HEC with a U3R of 0.71. <tables id="tabl0004" num="0004"><table frame="all"><title><b>Table 3 - HEC with HE-MS 2 - 3</b></title><tgroup cols="6"><colspec colnum="1" colname="col1" colwidth="45mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="31mm" /><colspec colnum="4" colname="col4" colwidth="16mm" /><colspec colnum="5" colname="col5" colwidth="16mm" /><colspec colnum="6" colname="col6" colwidth="43mm" /><thead><row><entry valign="top">Example</entry><entry valign="top">HE-MS</entry><entry valign="top">1% Aq. Viscosity (cP)</entry><entry valign="top">G' at 0.1 Hz</entry><entry valign="top">Fiber Count</entry><entry valign="top">Unsubstituted Trimer Ratio U3R</entry></row></thead><tbody><row><entry>13 Blocky HEC</entry><entry>2.3</entry><entry>18</entry><entry /><entry>4</entry><entry>0.324</entry></row><row><entry>14 Blocky HEC</entry><entry>2.3</entry><entry>18,860</entry><entry>5.3</entry><entry>3</entry><entry>0.233</entry></row><row><entry>15 Blocky HEC</entry><entry>3.0</entry><entry>14</entry><entry /><entry>1</entry><entry>0.456</entry></row><row><entry>16 Blocky HEC</entry><entry>2.6</entry><entry>11</entry><entry /><entry>1</entry><entry>0.364</entry></row><row><entry>17 Blocky HEC</entry><entry>2.6</entry><entry>10</entry><entry /><entry>3</entry><entry>0.313</entry></row><row><entry>Comparative 17C</entry><entry>2.6</entry><entry>14</entry><entry /><entry>>6</entry><entry>0.100</entry></row><row><entry>18 Blocky HEC</entry><entry>2.5</entry><entry>600</entry><entry /><entry>5</entry><entry>0.401</entry></row><row><entry>19 Blocky HEC</entry><entry>2.9</entry><entry>2,640</entry><entry /><entry>1</entry><entry>0.710</entry></row><row><entry>Comparative 19C</entry><entry>3.0</entry><entry>2,980</entry><entry /><entry>4</entry><entry>0.114</entry></row><row><entry>Comparative Tylose H200 X</entry><entry>2.2</entry><entry>200 @ 1.9 wt%</entry><entry /><entry>1</entry><entry>0.134</entry></row><row><entry>Comparative Natrosol 210 HI-VIS</entry><entry>2.5</entry><entry>5,200</entry><entry /><entry>1</entry><entry>0.124</entry></row><row><entry>Comparative Cellosize QP10000H</entry><entry>2.7</entry><entry>4,800</entry><entry>0.65</entry><entry>1</entry><entry>0.147</entry></row><row><entry>Comparative Natrosol 250 HHR-P</entry><entry>2.3</entry><entry>6,100</entry><entry>0.20</entry><entry>1</entry><entry>0.155</entry></row><row><entry>Comparative Natrosol 250 HHR</entry><entry>2.6</entry><entry>4,200</entry><entry>0.20</entry><entry>1</entry><entry>0.113</entry></row><row><entry>Comparative Cellosize HEC-25</entry><entry>2.8</entry><entry>4,500- 6,000</entry><entry /><entry>1</entry><entry>0.072</entry></row><row><entry>Comparative Natrosdl 250 H</entry><entry>2.5</entry><entry>2,300</entry><entry /><entry>1</entry><entry>0.158</entry></row><row><entry>Comparative Tylose H100000 YP</entry><entry>2.6</entry><entry>100,000 @ 1.9 wt%</entry><entry /><entry>1</entry><entry>0.152</entry></row></tbody></tgroup></table></tables>

Examples 20-23

(Reference Examples)

0078Table 3a details blocky HECs with an HE-MS in the range of 2 to 3 that have been further modified with hydrophobic and/or anionic reagents. Examples 20 and 21 have extremely high Brookfield viscosities and elasticities (G') consistent with strong associative network formation. <tables id="tabl0005" num="0005"><table frame="all"><title><b>Table 3a - Derivatized HEC with HE-MS 2 - 3</b></title><tgroup cols="8"><colspec colnum="1" colname="col1" colwidth="33mm" /><colspec colnum="2" colname="col2" colwidth="13mm" /><colspec colnum="3" colname="col3" colwidth="13mm" /><colspec colnum="4" colname="col4" colwidth="18mm" /><colspec colnum="5" colname="col5" colwidth="21mm" /><colspec colnum="6" colname="col6" colwidth="15mm" /><colspec colnum="7" colname="col7" colwidth="17mm" /><colspec colnum="8" colname="col8" colwidth="40mm" /><thead><row><entry valign="top">Example</entry><entry valign="top">HE- MS</entry><entry valign="top">HM (%)</entry><entry valign="top">Charge (DS)</entry><entry valign="top">1% Aq. Viscosity (cP)</entry><entry valign="top">G' at 0.1 Hz</entry><entry valign="top">Fiber Count</entry><entry valign="top">Unsubstituted Trimer Ratio U3R</entry></row></thead><tbody><row><entry>20 Blocky CMHMHEC (C16)</entry><entry>2.1</entry><entry>2.2</entry><entry>0.20</entry><entry>65,100</entry><entry>10</entry><entry>1</entry><entry>N/A</entry></row><row><entry>21 Blocky CMHMHEC (C16)</entry><entry>2.2</entry><entry>2.6</entry><entry>0.22</entry><entry>84,600</entry><entry>32</entry><entry>1</entry><entry>N/A</entry></row><row><entry>22 Blocky CMHMHEC (C16)</entry><entry>2.3</entry><entry>0.7</entry><entry>0.34</entry><entry>100</entry><entry /><entry>1</entry><entry>N/A</entry></row><row><entry>23 Blocky CMHMHEC (C16)</entry><entry>2.8</entry><entry>1.0</entry><entry>0.30</entry><entry>15120</entry><entry /><entry>1</entry><entry>N/A</entry></row></tbody></tgroup></table></tables>

Example 24

0079Example 24 in Table 4 demonstrates that a blocky HEC can be produced having an HE-MS above 3. This sample has an HE-MS of 3.8 yet still exhibits an U3R of 0.35 and has good solution properties with low fiber rating. In comparison, Comparative Example 24C, an HEC made by a regular process (caustic to AGU molar ratio AC1 = 1.30), has an U3R of 0.19 which is characteristic of a more uniform structure. Also shown in this Table are several commercial HECs with high HE-MS that have extremely low unsubstituted trimer ratios. These low U3Rs are consistent with a high degree of biostability as stated in the literature for Cellosize ER (enzyme resistant), Natrosol B (biostable), and Tylose HS type HECs products. <tables id="tabl0006" num="0006"><table frame="all"><title>Table 4 - HEC with HE-MS > 3</title><tgroup cols="5"><colspec colnum="1" colname="col1" colwidth="52mm" /><colspec colnum="2" colname="col2" colwidth="15mm" /><colspec colnum="3" colname="col3" colwidth="33mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><colspec colnum="5" colname="col5" colwidth="48mm" /><thead><row><entry valign="top">Example</entry><entry valign="top">HE- MS</entry><entry valign="top">1% Aq. Viscosity (cP)</entry><entry valign="top">Fiber Count</entry><entry valign="top">Unsubstituted Trimer Ratio U3R</entry></row></thead><tbody><row><entry>24 Blocky HEC</entry><entry>3.8</entry><entry>8</entry><entry>2</entry><entry>0.351</entry></row><row><entry>Comparative 24C</entry><entry>3.6</entry><entry>330 @ 2 wt%</entry><entry>3</entry><entry>0.191</entry></row><row><entry>Comparative Tylose HS 30000 YP2</entry><entry>3.1</entry><entry>Not measured</entry><entry /><entry>0.025</entry></row><row><entry>Comparative Natrosol 250 HBR</entry><entry>3.2</entry><entry>2,200</entry><entry>1</entry><entry>0.057</entry></row><row><entry>Comparative Natrosol 250 HHBR</entry><entry>3.3</entry><entry>5,300</entry><entry>1</entry><entry>0.036</entry></row><row><entry>Comparative Cellosize ER30000</entry><entry>3.7</entry><entry>Not measured</entry><entry /><entry>0.026</entry></row><row><entry>Comparative Cellosize ER52000</entry><entry>3.9</entry><entry>Not measured</entry><entry /><entry>0.028</entry></row><row><entry>Comparative Cellosize ER15000</entry><entry>3.9</entry><entry>Not measured</entry><entry /><entry>0.026</entry></row></tbody></tgroup></table></tables>

Examples 25-27

(Reference Examples)

0080Table 4a shows examples of derivatized blocky HECs that have an HE-MS greater than 3. Examples 22, 25 and 26 demonstrate that a range of water ratios in the process (shown in Table 1) can be used to produce the blocky structure. Example 27 shows that the reverse process can be used to produce a hydrophobe-modified blocky HEC as indicated by a U3R of 0.27. <tables id="tabl0007" num="0007"><table frame="all"><title><b>Table 4a - Derivatized HEC with HE-MS > 3</b></title><tgroup cols="7"><colspec colnum="1" colname="col1" colwidth="43mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="14mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><colspec colnum="5" colname="col5" colwidth="25mm" /><colspec colnum="6" colname="col6" colwidth="18mm" /><colspec colnum="7" colname="col7" colwidth="34mm" /><thead><row><entry valign="top">Example</entry><entry valign="top">HE-MS</entry><entry valign="top">HM (%)</entry><entry valign="top">Charge (DS)</entry><entry valign="top">1% Aq. Viscosity (cP)</entry><entry valign="top">Fiber Count</entry><entry valign="top">Unsubstituted Trimer Ratio U3R</entry></row></thead><tbody><row><entry>25 Blocky CMHMHEC (C16)</entry><entry>3.4</entry><entry>0.8</entry><entry>0.3</entry><entry>12,760</entry><entry>1</entry><entry>N/A</entry></row><row><entry>26 Blocky CMHMHEC (C16)</entry><entry>3.4</entry><entry>0.8</entry><entry>0.2</entry><entry>99</entry><entry>1</entry><entry>N/A</entry></row><row><entry>27 Blocky HMHEC (C16)</entry><entry>4.3</entry><entry>1.8</entry><entry /><entry>3,360</entry><entry>Hazy</entry><entry>0.274</entry></row><row><entry>Comparative Natrosol Plus 330 5 lots</entry><entry>3.8</entry><entry>0.8</entry><entry /><entry>300</entry><entry>1</entry><entry>0.010 ± 0.0060</entry></row></tbody></tgroup></table></tables>

Example 28

(Reference Example)

Architectural Coatings

0081Blocky HECs show enhanced thickening efficiency in architectural coating applications. Blocky HEC Example 2 and Natrosol 250 HHR product were evaluated in the following Ucar Latex 367 60-PVC flat paint formulation. The blocky HEC thickener was 19 % more efficient than the Natrosol 250 HHR product and provided a slight increase in high shear viscosity (HSV). Data is shown in Table 6. <tables id="tabl0008" num="0008"><table frame="all"><tgroup cols="2"><colspec colnum="1" colname="col1" colwidth="60mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><thead><row><entry namest="col1" nameend="col2" align="left" valign="top"><b>Ucar Latex 367 60 PVC Formulation</b></entry></row><row><entry valign="top"><b><u>Pigment Grind</u></b></entry><entry valign="top" /></row><row><entry valign="top" /><entry align="center" valign="top"><b>Grams</b></entry></row></thead><tbody><row><entry>Water</entry><entry align="right">1,696</entry></row><row><entry>Tamol 731 Dispersant</entry><entry align="right">62</entry></row><row><entry>KTPP</entry><entry align="right">13.6</entry></row><row><entry>Igepal CO-660</entry><entry align="right">29.9</entry></row><row><entry>AMP-95</entry><entry align="right">13.6</entry></row><row><entry>Propylene Glycol</entry><entry align="right">234.8</entry></row><row><entry>Rhodoline 640</entry><entry align="right">25.8</entry></row><row><entry>Water, Discretionary (Added as needed)</entry><entry align="right">1,260</entry></row><row><entry>TiPure R-931 Titanium Dioxide</entry><entry align="right">2,035</entry></row><row><entry>Satintone W Calcined Clay</entry><entry align="right">1,696</entry></row><row><entry># 10 White Calcium Carbonate</entry><entry align="right">2,714</entry></row><row><entry /><entry align="right" /></row><row><entry>Dispersed to Hegman 4 to 5 -</entry><entry align="right" /></row><row><entry /><entry align="right" /></row><row><entry>Letdown</entry><entry align="right" /></row><row><entry>Ucar Latex 367</entry><entry align="right">3,071</entry></row><row><entry>Texanol Coalescent</entry><entry align="right">107.2</entry></row><row><entry>Rhodoline 640</entry><entry align="right">25.8</entry></row><row><entry>Proxel GXL Preservative</entry><entry align="right">13.6</entry></row><row><entry /><entry align="right">13,000</entry></row><row><entry><b>Thickened Paints:</b></entry><entry align="right" /></row><row><entry /><entry align="right" /></row><row><entry>Base Paint</entry><entry align="right">230 g</entry></row><row><entry>Thickener + Water to 100 KU</entry><entry align="right">50 g</entry></row><row><entry align="center"><b>Total:</b></entry><entry align="right">280 g</entry></row><row><entry /><entry align="right" /></row><row><entry>Stormer, Initial</entry><entry align="right">95 KU</entry></row><row><entry>pH, Initial</entry><entry align="right">8</entry></row><row><entry /><entry align="right" /></row><row><entry>Solids, Weight %</entry><entry align="right">52</entry></row><row><entry>   Volume %</entry><entry align="right">32</entry></row><row><entry>PVC</entry><entry align="right">60.2</entry></row><row><entry>Lb/Gal</entry><entry align="right">11.66</entry></row></tbody></tgroup></table></tables><tables id="tabl0009" num="0009"><table frame="all"><title><b>Table 6: UCAR Latex 367 60 PVC Flat Paint Properties</b></title><tgroup cols="7"><colspec colnum="1" colname="col1" colwidth="30mm" /><colspec colnum="2" colname="col2" colwidth="29mm" /><colspec colnum="3" colname="col3" colwidth="40mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><colspec colnum="5" colname="col5" colwidth="12mm" /><colspec colnum="6" colname="col6" colwidth="19mm" /><colspec colnum="7" colname="col7" colwidth="16mm" /><thead><row><entry valign="top"><b>Thickener</b></entry><entry valign="top"><b>Thickener Conc. (wt%)</b></entry><entry valign="top"><b>Stormer (KU) Initial/Overnight</b></entry><entry valign="top"><b>HSV (Poise)</b></entry><entry valign="top"><b>Sag</b></entry><entry valign="top"><b>Leveling</b></entry><entry valign="top"><b>Hiding</b></entry></row></thead><tbody><row><entry>Natrosol 250HHR</entry><entry>0.43</entry><entry>95/97</entry><entry>0.6</entry><entry>10</entry><entry>5</entry><entry>0.987</entry></row><row><entry>Example 2</entry><entry>0.36</entry><entry>96/100</entry><entry>0.7</entry><entry>14</entry><entry>4</entry><entry>0.988</entry></row></tbody></tgroup></table></tables>

0082Hydrophobically-modified hydroxyethyl cellulose (HMHEC) is an important product used in the paint industry. There are many characteristics that this rheology modify provides to a paint formulation, such as spatter free paint application, solution stability, and thickening efficiency. It is generally used in conjunction with another thickener that provides improved brush viscosity (high shear viscosity, HSV). It would simplify the formulation to be able to use a HMHEC as the sole thickener to provide all of the important attributes. Hydrophobically modified blocky HECs are an improvement over a typical HMHEC, such as Natrosol Plus 330 product, by providing an improved high shear viscosity as well as other critical attributes.

0083The rheology modifiers were tested as follows either in the Ucar Latex 379G 70-PVC or Ucar Latex 367 60-PVC formulations. The data in Table 7 indicates that the blocky HMHECs provide high shear viscosities 44 - 67% higher with comparable or better paint properties as compared to Natrosol Plus 330 product. <tables id="tabl0010" num="0010"><table frame="none"><tgroup cols="3" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="54mm" /><colspec colnum="3" colname="col3" colwidth="28mm" /><thead><row><entry namest="col1" nameend="col2" align="left" valign="top"><b>Ucar Latex 379G 70-PVC Formulation Base Paint</b></entry><entry align="right" valign="top"><b>Grams/13,000g</b></entry></row></thead><tbody><row><entry><b>Pigment Grind</b></entry><entry /><entry align="right" /></row><row><entry /><entry>Water</entry><entry align="right">2,521 g</entry></row><row><entry /><entry>Nuosept 95</entry><entry align="right">32.4</entry></row><row><entry /><entry>Tamol 731A Dispersant</entry><entry align="right">64.7</entry></row><row><entry /><entry>Igepal CO-660</entry><entry align="right">31.0</entry></row><row><entry /><entry>Igepal CO-897</entry><entry align="right">43.6</entry></row><row><entry /><entry>AMP-95</entry><entry align="right">14.1</entry></row><row><entry /><entry>Propylene Glycol</entry><entry align="right">182.9</entry></row><row><entry /><entry>Rhodine 640</entry><entry align="right">14.1</entry></row><row><entry /><entry>Water, Discretionary,</entry><entry align="right">1,407</entry></row><row><entry /><entry>Ti-Pure R-931 TiO2</entry><entry align="right">1,055</entry></row><row><entry /><entry>ASP NC Clay</entry><entry align="right">2,814</entry></row><row><entry /><entry>ECC #10 White Calcium Carbonate</entry><entry align="right">2,110</entry></row><row><entry /><entry>Celite 281 Silica</entry><entry align="right">352</entry></row><row><entry /><entry>-Disperse to Hègman 4 to 5 -</entry><entry align="right" /></row><row><entry><b>Letdown</b></entry><entry /><entry align="right" /></row><row><entry /><entry>-All Discretionary Water in -</entry><entry align="right" /></row><row><entry /><entry>Ucar Latex 379G</entry><entry align="right">2,079</entry></row><row><entry /><entry>Texanol</entry><entry align="right">11.1</entry></row><row><entry /><entry>PA-454 Antifoam</entry><entry align="right">26.7</entry></row><row rowsep="1"><entry /><entry>Propylene Glycol</entry><entry align="right">140.7</entry></row><row><entry /><entry><b>Total</b></entry><entry align="right">13,000 g</entry></row><row><entry><b>Thickened Paints</b></entry><entry /><entry align="right" /></row><row><entry>Base Paint</entry><entry /><entry align="right">220 g</entry></row><row><entry namest="col1" nameend="col2" align="left">Thickener Solution + Water to 95 KU</entry><entry align="right">50</entry></row><row><entry /><entry>Total</entry><entry align="right">270 g</entry></row><row><entry /><entry>pH, initial (8.5 Target)</entry><entry align="right" /></row><row><entry /><entry>Density, Ib/100 gal</entry><entry align="right">11.3</entry></row><row><entry /><entry>Solids, Weight %</entry><entry align="right">47.8</entry></row><row><entry /><entry>   Volume%</entry><entry align="right">29.3</entry></row><row><entry /><entry>PVC, %</entry><entry align="right">69.9</entry></row></tbody></tgroup></table></tables><tables id="tabl0011" num="0011"><table frame="all"><title><b>Table 7: Paint Properties for Hydrophobically Modified Blocky HEC</b></title><tgroup cols="8"><colspec colnum="1" colname="col1" colwidth="29mm" /><colspec colnum="2" colname="col2" colwidth="32mm" /><colspec colnum="3" colname="col3" colwidth="23mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><colspec colnum="5" colname="col5" colwidth="17mm" /><colspec colnum="6" colname="col6" colwidth="19mm" /><colspec colnum="7" colname="col7" colwidth="12mm" /><colspec colnum="8" colname="col8" colwidth="16mm" /><thead><row><entry valign="top"><b>Thickener</b></entry><entry valign="top"><b>Paint Formulation</b></entry><entry valign="top"><b>Thickener Conc.(wt%)</b></entry><entry align="center" valign="top"><b>HSV (Poise)</b></entry><entry align="center" valign="top"><b>Spatt er</b></entry><entry align="center" valign="top"><b>Leveling</b></entry><entry align="center" valign="top"><b>Sag</b></entry><entry align="center" valign="top"><b>Hiding</b></entry></row></thead><tbody><row><entry>Natrosol Plus 330</entry><entry align="center">UCAR 379G 70 PVC</entry><entry align="center">0.66</entry><entry align="center">0.9</entry><entry align="center">9</entry><entry align="center">2</entry><entry align="center">18</entry><entry align="center">0.98</entry></row><row><entry>Example 7</entry><entry align="center">UCAR 379G 70 PVC</entry><entry align="center">0.67</entry><entry align="center">1.3</entry><entry align="center">9</entry><entry align="center">3</entry><entry align="center">14</entry><entry align="center">0.98</entry></row><row><entry>Natrosol Plus 330</entry><entry align="center">UCAR 367 60 PVC</entry><entry align="center">0.54</entry><entry align="center">0.9</entry><entry align="center">9</entry><entry align="center">2</entry><entry align="center">23</entry><entry align="center">0.98</entry></row><row><entry>Example 26</entry><entry align="center">UCAR 367 60 PVC</entry><entry align="center">0.57</entry><entry align="center">1.5</entry><entry align="center">8</entry><entry align="center">2</entry><entry align="center">23</entry><entry align="center">0.98</entry></row></tbody></tgroup></table></tables>

Example 29

(Reference Example)

Construction

0084Blocky HECs show enhanced viscosity in joint compounds. Blocky HEC Example 2 and Natrosol 250HHR product were evaluated as thickeners at 0.30 wt % in an all-purpose joint compound formulation, as described below. Table 8 shows that the formulation containing blocky HEC was 23% more efficient (joint compound viscosity) while maintaining good adhesion, workability, and cratering properties. <tables id="tabl0012" num="0012"><table frame="all"><title>All-Purpose Joint Compound Formulation</title><tgroup cols="3"><colspec colnum="1" colname="col1" colwidth="29mm" /><colspec colnum="2" colname="col2" colwidth="46mm" /><colspec colnum="3" colname="col3" colwidth="15mm" /><thead><row><entry valign="top"><b>Ingredients</b></entry><entry valign="top"><b>Supplier</b></entry><entry align="center" valign="top"><b>Wt%</b></entry></row></thead><tbody><row><entry>Ground CaCO3</entry><entry>Georgia White #9</entry><entry align="right">61</entry></row><row><entry>Attapulgite Clay</entry><entry>Gel B, Milwhite</entry><entry align="right">2.0</entry></row><row><entry>Mica</entry><entry>4-K, Oglebay Norton</entry><entry align="right">3.00</entry></row><row><entry>Latex dispersion</entry><entry>EVA or PVA latex (see Note 1)</entry><entry align="right">2.5</entry></row><row><entry>Propylene glycol</entry><entry>Aldrich</entry><entry align="right">0.35</entry></row><row><entry>Biocide</entry><entry>Trosan 174, Troy chemical</entry><entry align="right">0.05</entry></row><row><entry>Defoamer</entry><entry>Foamaster PD1WD, Cognis</entry><entry align="right">0.02</entry></row><row><entry>Thickener</entry><entry /><entry align="right">0.30</entry></row><row><entry>Water</entry><entry>Tap water</entry><entry align="right">30.6</entry></row><row><entry>Total</entry><entry /><entry align="right">100</entry></row></tbody></tgroup></table></tables><tables id="tabl0013" num="0013"><table frame="all"><title><b>Table 8: All Purpose Joint Compound Properties</b></title><tgroup cols="5"><colspec colnum="1" colname="col1" colwidth="40mm" /><colspec colnum="2" colname="col2" colwidth="54mm" /><colspec colnum="3" colname="col3" colwidth="20mm" /><colspec colnum="4" colname="col4" colwidth="35mm" /><colspec colnum="5" colname="col5" colwidth="19mm" /><thead><row><entry align="center" valign="top"><b>Thickener</b></entry><entry align="center" valign="top"><b>Joint Compound Viscosity (Brabender Units)</b></entry><entry align="center" valign="top"><b>Adhesion</b></entry><entry align="center" valign="top"><b>Cratering (1-10) 10 best</b></entry><entry align="center" valign="top"><b>5 months aging</b></entry></row></thead><tbody><row><entry>250HHXR Commercial HEC</entry><entry align="center">480</entry><entry align="center">100%</entry><entry align="center">7</entry><entry align="center">failed</entry></row><row><entry>Example 2</entry><entry align="center">590</entry><entry align="center">100%</entry><entry align="center">8</entry><entry align="center">excellent</entry></row></tbody></tgroup></table></tables>

0085Butyl-modified blocky HEC shows superior adhesion in lightweight joint compounds. Derivatized blocky HEC Example 8 and Nexton J20R product were evaluated as thickeners at 0.4 wt % in a lightweight joint compound formulation as shown below. Nexton J20R is a commercial modified HEC and was chosen as a control as it is commonly used in lightweight joint compound applications. Table 9 shows the joint compound with Example 8 had better adhesion and similar properties in thickening efficiency (high BU), cracking, and water retention as compared to the commercial Nexton J20R product. <tables id="tabl0014" num="0014"><table frame="all"><title>Light Weight Joint Compound Formulation</title><tgroup cols="2"><colspec colnum="1" colname="col1" colwidth="44mm" /><colspec colnum="2" colname="col2" colwidth="29mm" /><thead><row><entry align="center" valign="top"><b>Material</b></entry><entry align="center" valign="top"><b>Wt %</b></entry></row></thead><tbody><row><entry>Georgia White #9 CaCO3</entry><entry align="center">49.25</entry></row><row><entry>Attapulgite Clay (Gel B)</entry><entry align="center">3.2</entry></row><row><entry>SilCell 35/34 Treated Perlite</entry><entry align="center">4.75</entry></row><row><entry>Cellulosic Thickener</entry><entry align="center">0.40</entry></row><row><entry>Latex or Dispersible powder</entry><entry align="center">1.3 (active)</entry></row><row><entry>Biocide (Troysan 174)</entry><entry align="center">0.1</entry></row><row><entry>Water</entry><entry align="center">41.0</entry></row><row><entry>Total</entry><entry align="center">100</entry></row></tbody></tgroup></table></tables><tables id="tabl0015" num="0015"><table frame="all"><title><b>Table 9: Lightweight Joint Compound Properties</b></title><tgroup cols="7"><colspec colnum="1" colname="col1" colwidth="21mm" /><colspec colnum="2" colname="col2" colwidth="34mm" /><colspec colnum="3" colname="col3" colwidth="23mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><colspec colnum="5" colname="col5" colwidth="19mm" /><colspec colnum="6" colname="col6" colwidth="21mm" /><colspec colnum="7" colname="col7" colwidth="31mm" /><thead><row><entry align="center" valign="top">Polymer Sample</entry><entry align="center" valign="top">Joint Compound Viscosity (BU)</entry><entry align="center" valign="top">Workability*</entry><entry align="center" valign="top">Water Retention (%)</entry><entry align="center" valign="top">Cratering at RT*</entry><entry align="center" valign="top">Cracks* 110F/20 % RH</entry><entry align="center" valign="top">Adhesion (%) USG/NG Tape</entry></row></thead><tbody><row><entry align="center">Nexton J20R Control</entry><entry align="center">435</entry><entry align="center">4.5</entry><entry align="center">92.7</entry><entry align="center">4</entry><entry align="center">3.5</entry><entry align="center">62/56</entry></row></tbody></tgroup><tgroup cols="7"><colspec colnum="1" colname="col1" colwidth="21mm" /><colspec colnum="2" colname="col2" colwidth="34mm" /><colspec colnum="3" colname="col3" colwidth="23mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><colspec colnum="5" colname="col5" colwidth="19mm" /><colspec colnum="6" colname="col6" colwidth="21mm" /><colspec colnum="7" colname="col7" colwidth="31mm" /><thead><row><entry align="center" valign="top">Polymer Sample</entry><entry align="center" valign="top">Joint Compound Viscosity (BU)</entry><entry align="center" valign="top">Workability*</entry><entry align="center" valign="top">Water Retention (%)</entry><entry align="center" valign="top">Cratering at RT*</entry><entry align="center" valign="top">Cracks* 110F/ 20 % RH</entry><entry align="center" valign="top">Adhesion (%) USG/NG Tape</entry></row></thead><tbody><row><entry align="center">Example 8</entry><entry align="center">465</entry><entry align="center">3.5</entry><entry align="center">92.2</entry><entry align="center">3</entry><entry align="center">4</entry><entry align="center">95/93</entry></row><row><entry namest="col1" nameend="col7" align="left">* Scale 1-5, 5 best</entry></row></tbody></tgroup></table></tables>

0086Blocky HEC and derivatized blocky HEC can be used to replace clay in joint compounds. Blocky HEC and derivatized blocky HEC were evaluated in a clay-free joint compound formulation. Clay is a natural product with inconsistent performance and it generates cracks and craters in joint compounds. However, without the clay, joint compounds have poor sag resistance and less body. Examples 2 and 20 were tested at 0.5 wt % as the sole rheology modifier in the clay-free joint compound system with reduced mica levels as shown. These were compared with Natrosol 250 HHXR product. Table 10 shows the joint compound containing the Natrosol 250 HHXR product had poor sag resistance, open time, and workability, confirming the need for a structure builder like clay. On the other hand, Examples 2 and 20 produced excellent joint compounds with properties that are typically obtained with thickener and a full complement of attapulgite clay. <tables id="tabl0016" num="0016"><table frame="all"><title>Typical All-Purpose Joint Compound Formulation with and without Clay</title><tgroup cols="3"><colspec colnum="1" colname="col1" colwidth="34mm" /><colspec colnum="2" colname="col2" colwidth="51mm" /><colspec colnum="3" colname="col3" colwidth="36mm" /><thead><row><entry align="center" valign="top"><b>Ingredient</b></entry><entry align="center" valign="top"><b>Use Level(s) discussed herein</b></entry><entry align="center" valign="top"><b>"Typical" Use Levels</b></entry></row></thead><tbody><row><entry /><entry>Regular weight</entry><entry>Regular weight</entry></row><row><entry>Water</entry><entry>30-31 %</entry><entry>30-31 %</entry></row><row><entry>Ground CaCO3</entry><entry>64%</entry><entry>62-64%</entry></row><row><entry>Attapulgite clay</entry><entry /><entry>1.7-2.5%</entry></row><row><entry>Mica</entry><entry>1.5 %</entry><entry>5-8%</entry></row><row><entry>Biocide</entry><entry>0.1%</entry><entry>0.1%</entry></row><row><entry>Latex, PVA</entry><entry>2.5 %</entry><entry>25%</entry></row><row><entry>Thickener</entry><entry>0.5 %</entry><entry>0.4 - 0.5%</entry></row></tbody></tgroup></table></tables><tables id="tabl0017" num="0017"><img file="EP1858970B2_D0008.tif" /></tables>

Example 30

Paper

0087Blocky HEC is a highly efficient water retention agent in paper coatings. Blocky HEC Example 3, commercial samples Aqualon 7L1T CMC, and Natrosol 250GR were evaluated as thickeners and water retention aids in the paper coating formulation as shown below. The amount of rheology modifier necessary to maintain the Brookfield viscosity at 1500 +/-50 cps, the water loss, and Hercules high shear viscosity are shown in Table 11. Blocky HEC Example 3 and HEC 250GR are of similar molecular weights and solution viscosities; however, the blocky product has a significantly higher dosage efficiency than HEC 250GR while maintaining its low water loss rate. In addition, blocky HEC Example 3 has much lower water loss and higher dosage efficiency than Aqualon 7L1T CMC yet similar desirable high shear rheology. <tables id="tabl0018" num="0018"><table frame="all"><title>Paper coating formulation</title><tgroup cols="2"><colspec colnum="1" colname="col1" colwidth="53mm" /><colspec colnum="2" colname="col2" colwidth="81mm" /><thead><row><entry valign="top" /><entry align="center" valign="top"><b>Parts</b></entry></row></thead><tbody><row><entry>HC 60* .</entry><entry align="center">60</entry></row><row><entry>HC 90*</entry><entry align="center">40</entry></row><row><entry>Dow 620 SB latex</entry><entry align="center">12</entry></row><row><entry>Calcium stearate</entry><entry align="center">1.00</entry></row><row><entry>Dispex N-40 (dispersing agent)</entry><entry align="center">0.25</entry></row><row><entry>Solids (%)</entry><entry align="center">68+/-0.5</entry></row><row><entry>Viscosity (cps):</entry><entry align="center">1500 cps at ambient</entry></row><row><entry>Rheology modifier</entry><entry align="center">Aqualon CMC7L1T, HEC 250GR, invention Example 3</entry></row><row><entry namest="col1" nameend="col2" align="left">*Ground Calcium Carbonate (HydroCarb) from OMYA Inc.</entry></row></tbody></tgroup></table></tables><tables id="tabl0019" num="0019"><table frame="all"><title><b>Table 11: Paper Coating Properties</b></title><tgroup cols="7"><colspec colnum="1" colname="col1" colwidth="21mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="20mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><colspec colnum="5" colname="col5" colwidth="23mm" /><colspec colnum="6" colname="col6" colwidth="32mm" /><colspec colnum="7" colname="col7" colwidth="34mm" /><thead><row><entry align="center" valign="middle"><b>Thickener</b></entry><entry align="center" valign="middle"><b>HE-MS or DS</b></entry><entry align="center" valign="middle"><b>2% Viscosity (cPs)</b></entry><entry align="center" valign="middle"><b>Parts thickener/ 100 part filler</b></entry><entry align="center" valign="middle"><b>Water Loss (g/sq meter, 0.6 Bar/1min</b></entry><entry align="center" valign="middle"><b>High Shear Rheology 1^st Pass 2400/4400</b> RPM</entry><entry align="center" valign="middle"><b>High Shear Rheology 2^nd Pass 240014400</b> RPM</entry></row></thead><tbody><row><entry>Natrosol HEC 250G</entry><entry>2.5</entry><entry>300</entry><entry>0.75</entry><entry>91</entry><entry>84/56</entry><entry>54/48</entry></row><row><entry>Aqualon 7L1TCMC</entry><entry>0.7</entry><entry>100</entry><entry>0.99</entry><entry>168</entry><entry>42/34</entry><entry>34/30</entry></row><row><entry>Invention Example 3</entry><entry>1.8</entry><entry>191</entry><entry>0.52</entry><entry>98</entry><entry>49/37</entry><entry>41/35</entry></row></tbody></tgroup></table></tables>

Example 31

(Reference Example)

Personal Care

0088Blocky HEC shows enhanced viscosity in personal care formulations. Natrosol^® hydroxyethyl cellulose type 250HHR and blocky HEC Example 2 were compared at 0.7 wt% for thickening efficiency in the hair conditioner formulation shown below.

0089Hair Conditioner <dl id="dl0001" compact="compact"><dt>90.94g</dt><dd>Deionized water</dd><dt>00.70g</dt><dd>Thickening polymer (Natrosol^® 250HHR, blocky HEC example 2)</dd><dt>02.00g</dt><dd>Cetyl alcohol</dd><dt>00.50g</dt><dd>Potassium Chloride</dd><dt>02.00g</dt><dd>Isopropyl Myristate</dd><dt>As required -</dt><dd>citric acid to adjust pH</dd><dt>As required -</dt><dd>Sodium hydroxide to adjust pH</dd><dt>00.50g</dt><dd>Germaben II</dd></dl>

Procedure:

0090The thickening polymer was added to water under agitation. Next, the pH was adjusted to 8.0 to 8.5. The slurry was stirred for at least 30 minutes or until the polymer dissolved. The solution was heated to about 65°C and cetyl alcohol was added and mixed until homogeneous. The mixture was cooled to about 50°C and potassium chloride was added. Isopropyl myristate was added and mixed until the mixture looked homogeneous. The pH of the mixture was adjusted to 5.3 - 5.5 with citric acid and/or NaOH solution. The conditioner was preserved with 0.5 g Germaben II and mixed until the mixture reached room temperature.

0091The viscosity of the conditioning formulation containing blocky HEC Example 2 was 1,550 cP, as compared to the control containing Natrosol^® 250HHR at 910 cPs, a 70% improvement in thickening efficiency.

0092Hydrophobically modified blocky HECs show enhanced viscosity stability in oil-in-water emulsions. They were evaluated as a polymeric emulsifier / stabilizer in a typical emulsion formulation shown. Examples 20 and 21 were compared against commercial polymeric emulsifiers (Natrosol Plus 330, 331, and PolySurf 67). In addition, Pemulen TR-1, Pemulen TR-2 and Carbopol ETD 2020 products, commonly used hydrophobically modified acrylate cross-polymers, were included in the comparison. Table 12 and 13 show the viscosity data for one-month storage at room temperature and 40° C, respectively. Examples 20 and 21 have dramatically improved emulsifying and stabilizing properties over the commercial hydrophobically modified HECs. Furthermore, the emulsifying/stabilizing efficiency is near that of Pemulen TR-1, Pemulen TR-2, and Carbopol ETD 2020, which are extremely efficient emulsifying/stabilizing polymers in the market. The thickening efficiency is even better than that of Pemulen TR-2. <tables id="tabl0020" num="0020"><table frame="all"><title>Composition of Basic Emulsion Formulation</title><tgroup cols="2"><colspec colnum="1" colname="col1" colwidth="47mm" /><colspec colnum="2" colname="col2" colwidth="25mm" /><thead><row><entry align="center" valign="top">Ingredients</entry><entry align="center" valign="top">Wt%</entry></row></thead><tbody><row rowsep="0"><entry align="center">Distilled water</entry><entry align="center">q.s. to 100.0</entry></row><row rowsep="0"><entry align="center">Polymeric emulsifier/stabilizer</entry><entry align="center">0.5-1.00</entry></row><row rowsep="0"><entry align="center">Carnation oil (mineral oil)</entry><entry align="center">10.00</entry></row><row><entry align="center">Germaben II (preservative)</entry><entry align="center">0.20</entry></row></tbody></tgroup></table></tables>

<u>Procedure:</u>

0093<ul id="ul0003" list-style="dash" compact="compact"><li>Prepare stock solution of polymeric emulsifier/stabilizer - Add mineral oil to the aqueous phase and Germaben II</li><li>Mix the formulation with Braun kitchen mixer for 3 minutes at speed 5.</li><li>(All emulsions prepared had a pH 5-7)</li></ul><tables id="tabl0021" num="0021"><table frame="all"><title>Table 12: Viscosity stability of oil-in-water emulsions upon 4 weeks storage at room temperature</title><tgroup cols="8"><colspec colnum="1" colname="col1" colwidth="38mm" /><colspec colnum="2" colname="col2" colwidth="14mm" /><colspec colnum="3" colname="col3" colwidth="19mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><colspec colnum="5" colname="col5" colwidth="20mm" /><colspec colnum="6" colname="col6" colwidth="20mm" /><colspec colnum="7" colname="col7" colwidth="20mm" /><colspec colnum="8" colname="col8" colwidth="20mm" /><thead><row><entry morerows="1" align="center" valign="top">Polymer</entry><entry morerows="1" align="center" valign="top">Wt%</entry><entry namest="col3" nameend="col8" align="center" valign="top">Viscosity 1 wk (mPa.s; spl/rpm 2 wks C/10)</entry></row><row><entry align="center" valign="top">24 hrs</entry><entry align="center" valign="top">3 days</entry><entry align="center" valign="top" /><entry align="center" valign="top" /><entry align="center" valign="top">3wks</entry><entry align="center" valign="top">4 wks</entry></row></thead><tbody><row><entry>Blank (without polymer)</entry><entry align="center">-</entry><entry align="center">10(2/30)</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase</entry></row><row><entry>Carbopol ETD 2020</entry><entry align="center">0.5</entry><entry align="center">23200</entry><entry align="center">25100</entry><entry align="center">25900</entry><entry align="center">26800</entry><entry align="center">25100</entry><entry align="center">24700</entry></row><row><entry /><entry align="center">1.0</entry><entry align="center">58400</entry><entry align="center">63000</entry><entry align="center">59500</entry><entry align="center">62000</entry><entry align="center">62200</entry><entry align="center">63000</entry></row><row><entry>Pemulen TR-1</entry><entry align="center">0.5</entry><entry align="center">13400</entry><entry align="center">13400</entry><entry align="center">13000</entry><entry align="center">13400</entry><entry align="center">11700</entry><entry align="center">11600</entry></row><row><entry>Pemulen TR-2</entry><entry align="center">0.5</entry><entry align="center">2280*</entry><entry align="center">2180*</entry><entry align="center">2140*</entry><entry align="center">2080*</entry><entry align="center">2120*</entry><entry align="center">2100*</entry></row><row><entry>Natrosol <i>Plus</i> 330</entry><entry align="center">1.0</entry><entry align="center">1200*</entry><entry align="center">880*</entry><entry align="center">920*</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry></row><row><entry>Natrosol <i>Plus</i> 331</entry><entry align="center">1.0</entry><entry align="center">2880*</entry><entry align="center">1660*</entry><entry align="center">780*</entry><entry align="center">600*</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry></row><row><entry>Polysurf 67</entry><entry align="center">1.0</entry><entry align="center">17400</entry><entry align="center">15100</entry><entry align="center">14100</entry><entry align="center">13700</entry><entry align="center">13600</entry><entry align="center">13400</entry></row><row><entry morerows="1">Example 20</entry><entry align="center">0.5</entry><entry align="center">9000</entry><entry align="center">8000</entry><entry align="center">7000</entry><entry align="center">8200</entry><entry align="center">8100</entry><entry align="center">8000</entry></row><row><entry align="center">1.0</entry><entry align="center">28300</entry><entry align="center">27000</entry><entry align="center">22500</entry><entry align="center">26600</entry><entry align="center">25000</entry><entry align="center">24600</entry></row><row><entry morerows="1">Example 21</entry><entry align="center">0.5</entry><entry align="center">5700</entry><entry align="center">5500</entry><entry align="center">6000</entry><entry align="center">7000</entry><entry align="center">7000</entry><entry align="center">7000</entry></row><row><entry align="center">1.0</entry><entry align="center">21300</entry><entry align="center">21500</entry><entry align="center">23500</entry><entry align="center">25900</entry><entry align="center">25800</entry><entry align="center">25600</entry></row><row><entry namest="col1" nameend="col8" align="left">*spl/rpm 3/30</entry></row></tbody></tgroup></table></tables><tables id="tabl0022" num="0022"><table frame="all"><title><b>Table 13: Viscosity stability of oil-in-water emulsions upon 4 weeks storage at 40°C</b></title><tgroup cols="8"><colspec colnum="1" colname="col1" colwidth="37mm" /><colspec colnum="2" colname="col2" colwidth="13mm" /><colspec colnum="3" colname="col3" colwidth="18mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><colspec colnum="5" colname="col5" colwidth="20mm" /><colspec colnum="6" colname="col6" colwidth="20mm" /><colspec colnum="7" colname="col7" colwidth="20mm" /><colspec colnum="8" colname="col8" colwidth="20mm" /><thead><row><entry morerows="1" align="center" valign="top">Polymer</entry><entry morerows="1" align="center" valign="top">Wt%</entry><entry namest="col3" nameend="col8" align="center" valign="top">Viscosity (mP.s; spl/rpm 1wk 2wk C/10)</entry></row><row><entry align="center" valign="top">24 hrs</entry><entry align="center" valign="top">3 days</entry><entry align="center" valign="top" /><entry align="center" valign="top" /><entry align="center" valign="top">3wks</entry><entry align="center" valign="top">4 wks</entry></row></thead><tbody><row><entry align="center">Blank (without polymer)</entry><entry align="center">-</entry><entry align="center">10(2/30)</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase</entry></row><row><entry align="center">Carbopol ETD 2020</entry><entry align="center">0.5</entry><entry align="center">23200</entry><entry align="center">28000</entry><entry align="center">28600</entry><entry align="center">26700</entry><entry align="center">26600</entry><entry align="center">25500</entry></row><row><entry align="center">Carbopol ETD 2020</entry><entry align="center">1.0</entry><entry align="center">58400</entry><entry align="center">69500</entry><entry align="center">61100</entry><entry align="center">60800</entry><entry align="center">61200</entry><entry align="center">61300</entry></row><row><entry align="center">Pemulen TR-1</entry><entry align="center">0.5</entry><entry align="center">13400</entry><entry align="center">13000</entry><entry align="center">13400</entry><entry align="center">13400</entry><entry align="center">12100</entry><entry align="center">12050</entry></row><row><entry align="center">Pemulen TR-2</entry><entry align="center">.0.5</entry><entry align="center">2280*</entry><entry align="center">2320*</entry><entry align="center">2200*</entry><entry align="center">2200*</entry><entry align="center">2020*</entry><entry align="center">2000*</entry></row><row><entry align="center">Natrosol <i>Plus</i> 330</entry><entry align="center">1.0</entry><entry align="center">1200*</entry><entry align="center">920*</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry></row><row><entry align="center">Natrosol <i>Plus</i> 331</entry><entry align="center">1.0</entry><entry align="center">2880*</entry><entry align="center">1080*</entry><entry align="center">1000*</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry><entry align="center">Phase sep</entry></row><row><entry align="center">Polysurf 67</entry><entry align="center">1.0</entry><entry align="center">17400</entry><entry align="center">14300</entry><entry align="center">13400</entry><entry align="center">12800</entry><entry align="center">12600</entry><entry align="center">12200</entry></row><row><entry morerows="1" align="center">Example 20</entry><entry align="center">0.5</entry><entry align="center">9000</entry><entry align="center">8000</entry><entry align="center">8000</entry><entry align="center">8500</entry><entry align="center">8300</entry><entry align="center">8300</entry></row><row><entry align="center">1.0</entry><entry align="center">28300</entry><entry align="center">25000</entry><entry align="center">22500</entry><entry align="center">25300</entry><entry align="center">24900</entry><entry align="center">24200</entry></row><row><entry morerows="1" align="center">Example 21</entry><entry align="center">0.5</entry><entry align="center">5700</entry><entry align="center">6000</entry><entry align="center">7000</entry><entry align="center">7700</entry><entry align="center">7800</entry><entry align="center">7700</entry></row><row><entry align="center">1.0</entry><entry align="center">21300</entry><entry align="center">25000</entry><entry align="center">26000</entry><entry align="center">27200</entry><entry align="center">27600</entry><entry align="center">27600</entry></row><row><entry namest="col1" nameend="col8" align="left">*spl/rpm 3/30</entry></row></tbody></tgroup></table></tables>

0094Examples 20 and 21 were evaluated in the surfactant formulation shown to investigate compatibility in general personal care and household applications. Example 20 and 21 were compared against commercial rheology modifiers Natrosol Plus 330, and PolySurf 67 products. In addition, Carbopol ETD 2020 product was included in the comparison. Table 14 shows that the hydrophobically modified blocky HEC Examples 20 and 21 are very efficient cellulosic thickeners. Example 21 resulted in clear solutions unlike any of the others tested. <tables id="tabl0023" num="0023"><table frame="all"><title>Composition of basic surfactant formulation</title><tgroup cols="4"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><colspec colnum="3" colname="col3" colwidth="51mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><thead><row><entry align="center" valign="top"><b>Ingredients</b></entry><entry align="center" valign="top"><b>Wt%</b></entry><entry align="center" valign="top"><b>Ingredients</b></entry><entry align="center" valign="top"><b>Wt%</b></entry></row></thead><tbody><row rowsep="0"><entry align="center">Texapon 28</entry><entry align="center">25.00</entry><entry align="center">Sodiumlauryl ether sulfate (SLES)</entry><entry align="center">7.00</entry></row><row rowsep="0"><entry align="center">Plantacare 2000 UP</entry><entry align="center">5.00</entry><entry align="center">Decyl Glucoside (APG)</entry><entry align="center">2.65</entry></row><row rowsep="0"><entry align="center">Tegobetaine L7</entry><entry align="center">10.00</entry><entry align="center">Cocamidopropylbetaine (CAPO)</entry><entry align="center">3.10</entry></row><row rowsep="0"><entry align="center">Thickener</entry><entry align="center">-.-</entry><entry align="center">Thickener</entry><entry align="center">-.-</entry></row><row><entry align="center">Citric acid</entry><entry align="center">pH 5.5-6.5</entry><entry align="center">Citric acid</entry><entry align="center">pH 5.5-6.5</entry></row><row rowsep="0"><entry align="center">Germaben II</entry><entry align="center">0.20</entry><entry align="center">Germaben II</entry><entry align="center">0.20</entry></row><row><entry align="center">Water</entry><entry align="center">q.s. to 100.00</entry><entry align="center">Water</entry><entry align="center">.q.s. to 100.0</entry></row></tbody></tgroup></table></tables>

Procedure:

0095<ul id="ul0004" list-style="dash" compact="compact"><li>Dissolve thickener in demineralized water. - Add Texapon 28 to thickener solution and mix homogeneously.</li><li>Add Plantacare 2000 UP to thickener solution and mix homogeneously.</li><li>Add Tegobetaine L7 to thickener solution and mix homogeneously.</li><li>Adjust pH with citric acid to 5.5 -6.5.</li><li>Add Germaben II.</li></ul><tables id="tabl0024" num="0024"><table frame="all"><title><b>Table 14: Viscosity and appearance of surfactant formulation with thickener</b></title><tgroup cols="4"><colspec colnum="1" colname="col1" colwidth="34mm" /><colspec colnum="2" colname="col2" colwidth="33mm" /><colspec colnum="3" colname="col3" colwidth="34mm" /><colspec colnum="4" colname="col4" colwidth="36mm" /><thead><row><entry align="center" valign="top"><b>Polymer</b></entry><entry namest="col2" nameend="col3" align="center" valign="top"><b>Brookfield viscosity (mPa.s, spd/rpm 3/30)</b></entry><entry align="center" valign="top"><b>Appearance</b></entry></row></thead><tbody><row><entry morerows="2" align="center">Polysurf 67 CS</entry><entry align="center">0.75 wt%</entry><entry align="center">1260</entry><entry align="center">Very hazy</entry></row><row><entry align="center">1.00 wt%</entry><entry align="center">3400</entry><entry align="center">Very hazy</entry></row><row><entry align="center">1.25 wt%</entry><entry align="center">6200*</entry><entry align="center">Very hazy</entry></row><row><entry morerows="3" align="center">Natrosol Plus 330 CS</entry><entry align="center">1.00 wt%</entry><entry align="center">1040</entry><entry align="center">Slightly hazy</entry></row><row><entry align="center">1.15 wt%</entry><entry align="center">1500</entry><entry align="center">Slightly hazy</entry></row><row><entry align="center">1.30 wt%</entry><entry align="center">2500</entry><entry align="center">Slightly hazy</entry></row><row><entry align="center">1.50 wt%</entry><entry align="center">3400</entry><entry align="center">Hazy</entry></row><row><entry morerows="2" align="center">Carbopol ETD 2020</entry><entry align="center">0.50 wt%</entry><entry align="center">1240</entry><entry align="center">Hazy</entry></row><row><entry align="center">0.60 wt%</entry><entry align="center">2300</entry><entry align="center">Very hazy</entry></row><row><entry align="center">0.65 wt%</entry><entry align="center">3160</entry><entry align="center">Very hazy</entry></row><row><entry morerows="1" align="center">Example 20</entry><entry align="center">0.75 wt%</entry><entry align="center">2160</entry><entry align="center">Very hazy</entry></row><row><entry align="center">0.90 wt%</entry><entry align="center">5000*</entry><entry align="center">Very hazy</entry></row><row><entry morerows="1" align="center">Example 21</entry><entry align="center">0.75 wt%</entry><entry align="center">1360</entry><entry align="center">Clear</entry></row><row><entry align="center">1.00 wt%</entry><entry align="center">5500*</entry><entry align="center">Clear</entry></row><row><entry namest="col1" nameend="col4" align="left">*spl/rpm is 4/30</entry></row></tbody></tgroup></table></tables>

0096Examples 20 and 21 were evaluated as a gelling agent in an aqueous solution for hair styling gels. In addition, Carbopol Ultrez 10 (carbomer) and Carbopol ETD 2020 (C10-C30 modified acrylate), Natrosol 250 HHR, Natrosol 250 HR and Klucel H, commonly used gelling agents were included in the comparison.

0097The thickening efficiency and suspending power of Examples 20 and 21 was better than that of commercial HECs and HPC. Furthermore, example 21 showed a carbopol like texture (stiff and elastic gel), while the others were considered as flowable gels. The electrolyte tolerance of examples 20 and 21 was better compared to Carbopol Ultrez 10 and Carbopol ETD 2020.

Example 32

(Reference Example)

Completion / Workover Fluids

0098Completion fluids are composed of a variety of brines of different salinity characterized by a density ranging from 8.5 ppg (pound per gallon) for seawater up to 19.2 ppg for heavy brines containing zinc and calcium bromide salts. Standard high viscosity HEC is commonly used as a viscosifier for brines ranging from 9-13 ppg. There presently is not an efficient viscosifier for heavy brines with a density ranging from 14 ppg (CaBr₂) to 19.2 ppg (ZnBr₂/CaBr₂). These brines have a very low level of free water content available, and therefore, do not promote optimum hydration of standard HECs. These brines are characterized by a very low pH (pH&lt; 1 for ZnBr₂/CaBr₂).

0099Blocky HEC Example 2 was evaluated in 4 different brine systems (freshwater, salt-saturated water, CaBr₂ and ZnBr₂/CaBr₂) at 0.57 wt %. These were compared to a standard HEC widely used in completion fluids (Natrosol HI-VIS). The viscosity and fluid loss properties were measured after static aging overnight at room temperature (Tables 15a-d).

0100Blocky HEC Example 2 showed exceptional thickening in the high density, heavy brine solutions (characterized by low water activity) as detailed by the high apparent viscosities (A.V.) and yield values (Yv) that developed in these systems (Tables 15 c-d). In contrast, commercial HI-VIS did not go into solution in these low water activity systems. Additionally, the blocky HEC sample developed appreciable low-end rheology as reflected by the 6 and 3- rpm Fann dial readings (DR), and showed appropriate fluid loss (F.L.) values. <tables id="tabl0025" num="0025"><table frame="all"><tgroup cols="11"><colspec colnum="1" colname="col1" colwidth="14mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="13mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><colspec colnum="5" colname="col5" colwidth="15mm" /><colspec colnum="6" colname="col6" colwidth="11mm" /><colspec colnum="7" colname="col7" colwidth="11mm" /><colspec colnum="8" colname="col8" colwidth="14mm" /><colspec colnum="9" colname="col9" colwidth="14mm" /><colspec colnum="10" colname="col10" colwidth="18mm" /><colspec colnum="11" colname="col11" colwidth="19mm" /><thead><row><entry namest="col1" nameend="col11" align="center" valign="top">Table 15-a: Rheology/FL performance of various HEC samples in Demineralized water</entry></row><row><entry namest="col1" nameend="col3" align="center" valign="top">Fluid System</entry><entry align="center" valign="top">Sample</entry><entry align="center" valign="top">Final</entry><entry namest="col6" nameend="col7" align="center" valign="top">Fann DR</entry><entry namest="col8" nameend="col10" align="center" valign="top">Rheology</entry><entry morerows="1" align="center" valign="top">Fluid Loss (ml)</entry></row><row><entry align="center" valign="top">Brine</entry><entry align="center" valign="top">Density ppg</entry><entry align="center" valign="top">Initial pH</entry><entry align="center" valign="top">Ref.</entry><entry align="center" valign="top">Ph Aft. Ag.</entry><entry align="center" valign="top">6 rpm</entry><entry align="center" valign="top">3 rpm</entry><entry align="center" valign="top">A.V. cPs</entry><entry align="center" valign="top">P.V. cPs</entry><entry align="center" valign="top">Yv Lb/ 100ft2</entry></row></thead><tbody><row><entry align="center">Water</entry><entry align="center">8.3</entry><entry align="center">7.3</entry><entry align="center">Example 2</entry><entry align="center">10.9</entry><entry align="center">11</entry><entry align="center">7</entry><entry align="center">48</entry><entry align="center">21</entry><entry align="center">54</entry><entry align="center">34</entry></row><row><entry align="center" /><entry align="center" /><entry align="center" /><entry align="center">Natrosol HI-VIS</entry><entry align="center">10.1</entry><entry align="center">12</entry><entry align="center">8</entry><entry align="center">45</entry><entry align="center">19</entry><entry align="center">52</entry><entry align="center">31</entry></row></tbody></tgroup></table></tables><tables id="tabl0026" num="0026"><table frame="all"><tgroup cols="11"><colspec colnum="1" colname="col1" colwidth="20mm" /><colspec colnum="2" colname="col2" colwidth="19mm" /><colspec colnum="3" colname="col3" colwidth="13mm" /><colspec colnum="4" colname="col4" colwidth="22mm" /><colspec colnum="5" colname="col5" colwidth="14mm" /><colspec colnum="6" colname="col6" colwidth="11mm" /><colspec colnum="7" colname="col7" colwidth="11mm" /><colspec colnum="8" colname="col8" colwidth="14mm" /><colspec colnum="9" colname="col9" colwidth="14mm" /><colspec colnum="10" colname="col10" colwidth="16mm" /><colspec colnum="11" colname="col11" colwidth="15mm" /><thead><row><entry namest="col1" nameend="col11" align="center" valign="top">Table 15-b: Rheology/FL performance of various HEC samples in 36% NaCl Solution</entry></row><row><entry align="center" valign="top" /><entry align="center" valign="top">Fluid System</entry><entry align="center" valign="top" /><entry align="center" valign="top">Sample</entry><entry align="center" valign="top">Final</entry><entry namest="col6" nameend="col7" align="center" valign="top">Fann DR</entry><entry namest="col8" nameend="col10" align="center" valign="top">Rheology</entry><entry morerows="1" align="center" valign="top">Fluid Loss (ml)</entry></row><row><entry align="center" valign="top">Brine</entry><entry align="center" valign="top">Density ppg</entry><entry align="center" valign="top">Initial pH</entry><entry align="center" valign="top">Ref.</entry><entry align="center" valign="top">Ph Aft. Ag.</entry><entry align="center" valign="top">6 rpm</entry><entry align="center" valign="top">3 rpm</entry><entry align="center" valign="top">A.V. cPs</entry><entry align="center" valign="top">P.V. cPs</entry><entry align="center" valign="top">Yv Lb/ 100ft2</entry></row></thead><tbody><row><entry align="center">Saturated Salt</entry><entry align="center">10.0</entry><entry align="center">8.1</entry><entry align="center">Example 2</entry><entry align="center">10.4</entry><entry align="center">2</entry><entry align="center">1</entry><entry align="center">18</entry><entry align="center">15</entry><entry align="center">7</entry><entry align="center">13.2</entry></row><row><entry align="center">(36% NaCl)</entry><entry align="center" /><entry align="center" /><entry align="center">Natrosol HI-VIS</entry><entry align="center">10.2</entry><entry align="center">11</entry><entry align="center">7</entry><entry align="center">55</entry><entry align="center">26</entry><entry align="center">58</entry><entry align="center">3.1.2</entry></row></tbody></tgroup></table></tables><tables id="tabl0027" num="0027"><table frame="all"><tgroup cols="11"><colspec colnum="1" colname="col1" colwidth="15mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="13mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><colspec colnum="5" colname="col5" colwidth="14mm" /><colspec colnum="6" colname="col6" colwidth="11mm" /><colspec colnum="7" colname="col7" colwidth="11mm" /><colspec colnum="8" colname="col8" colwidth="14mm" /><colspec colnum="9" colname="col9" colwidth="17mm" /><colspec colnum="10" colname="col10" colwidth="14mm" /><colspec colnum="11" colname="col11" colwidth="22mm" /><thead><row><entry namest="col1" nameend="col11" align="center" valign="top">Table 15-c: Rheo logy/FL performance of various HEC samples in CaBr2 Brine</entry></row><row><entry namest="col1" nameend="col3" align="center" valign="top">Fluid system</entry><entry align="center" valign="top">Sample</entry><entry align="center" valign="top">Final</entry><entry namest="col6" nameend="col7" align="center" valign="top">Fann DR</entry><entry namest="col8" nameend="col10" align="center" valign="top">Rheology</entry><entry morerows="1" align="center" valign="top">Fluid Loss (ml)</entry></row><row><entry align="center" valign="top">Brine</entry><entry align="center" valign="top">Density ppg</entry><entry align="center" valign="top">Initial pH</entry><entry align="center" valign="top">Ref.</entry><entry align="center" valign="top">PH Aft. 6 Ag.</entry><entry align="center" valign="top">rpm</entry><entry align="center" valign="top">3 rpm</entry><entry align="center" valign="top">A.V. cPs</entry><entry align="center" valign="top">P.v.cPs</entry><entry align="center" valign="top">Yv Lb/ 100ft²</entry></row></thead><tbody><row><entry align="center">CaBr2</entry><entry align="center">14.5</entry><entry align="center">7.43</entry><entry align="center">Example 2</entry><entry align="center">7.5</entry><entry align="center">48</entry><entry align="center">34</entry><entry align="center">132</entry><entry align="center">60</entry><entry align="center">145</entry><entry align="center">29</entry></row><row><entry namest="col1" nameend="col3" align="center">Did not fully go into solution</entry><entry align="center">Natrosol HI-VIS</entry><entry align="center">7.7</entry><entry align="center">7</entry><entry align="center">4.4</entry><entry align="center">49</entry><entry align="center">32</entry><entry align="center">33</entry><entry align="center">Blowout</entry></row></tbody></tgroup></table></tables><tables id="tabl0028" num="0028"><table frame="all"><tgroup cols="11"><colspec colnum="1" colname="col1" colwidth="24mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><colspec colnum="3" colname="col3" colwidth="13mm" /><colspec colnum="4" colname="col4" colwidth="21mm" /><colspec colnum="5" colname="col5" colwidth="18mm" /><colspec colnum="6" colname="col6" colwidth="11mm" /><colspec colnum="7" colname="col7" colwidth="11mm" /><colspec colnum="8" colname="col8" colwidth="13mm" /><colspec colnum="9" colname="col9" colwidth="13mm" /><colspec colnum="10" colname="col10" colwidth="17mm" /><colspec colnum="11" colname="col11" colwidth="13mm" /><thead><row><entry namest="col1" nameend="col11" align="center" valign="top">Table 15-d: Rheology/FL performance of various HEC samples in ZnBr2/CaBr2 brine</entry></row><row><entry namest="col1" nameend="col3" align="center" valign="top">Fluid system</entry><entry align="center" valign="top">Sample</entry><entry align="center" valign="top">Final PH Aft Ag.</entry><entry namest="col6" nameend="col7" align="center" valign="top">Fann DR</entry><entry namest="col8" nameend="col10" align="center" valign="top">Rheology</entry><entry morerows="1" align="center" valign="top">Fluid Loss (ml)</entry></row><row><entry align="center" valign="top">Brine</entry><entry align="center" valign="top">Density Ppg</entry><entry align="center" valign="top">Initial pH</entry><entry align="center" valign="top">Ref.</entry><entry align="center" valign="top" /><entry align="center" valign="top">6 rpm</entry><entry align="center" valign="top">3 rpm</entry><entry align="center" valign="top">A.V. cPs</entry><entry align="center" valign="top">P.V. cPs</entry><entry align="center" valign="top">Yv lb/ 100ft2</entry></row></thead><tbody><row><entry align="center">ZnBr2/CaBr2</entry><entry align="center">19.2</entry><entry align="center">0.79</entry><entry align="center">Example 2</entry><entry align="center">1.4</entry><entry align="center">84</entry><entry align="center">68</entry><entry namest="col8" nameend="col10" align="center">Out of Scale</entry><entry align="center">167</entry></row><row><entry namest="col1" nameend="col3" align="center" /><entry align="center">Natrosol HI-VIS</entry><entry align="center">1.23</entry><entry namest="col6" nameend="col11" align="center">Did not go into solution</entry></row></tbody></tgroup></table></tables>

Example 33

Pharmaceuticals

0101Blocky HEC excipients provide superior tablet hardness. HEC is used in the pharmaceutical industry as an excipient to provide a swellable diffusion barrier in controlled release applications. The gel matrix it forms limits the diffusion of aqueous fluids into a system and dissolved actives out of the system. Currently, HEC produced by Aqualon (Natrosol^® 250 series of pharmaceutical grade polymers) holds the majority share of HEC used in the pharmaceutical industry.

0102HEC has some unique modified release properties not duplicated by hydroxypropylmethyl cellulose (HPMC) and hydroxypropyl cellulose (HPC). However, current knowledge is that current commercial grades of HEC show significantly inferior compression properties when compared to HPMC and HPC. The poor compactibility of this polymer generally makes the polymer suitable for only wet granulation processing, rather than direct compression processing which is frequently the industry preference.

0103In order to improve this limitation, scientists at Astra Zeneca in <patcit id="pcit0013" dnum="WO0219990A1"><text>International Patent Application, WO 02/19990 A1</text></patcit> describe a procedure whereby HEC is purified by dissolution in water before precipitation via addition of organic solvent. The precipitate is washed and then milled in a specific manner. The purified HEC has markedly improved tablet compactibility.

0104In accordance with the present invention is the use of blocky HEC material that is highly compressible for making direct compressible tablets for use in compaction applications such as sustained release tablets for pharmaceutical, household, and agricultural applications.

0105Table 16 shows the strength of pure polymer tablets (with 1 % stearic acid for lubrication) made from regular HEC, blocky HEC and commercial Natrosol 250 HHX Pharm HEC. Blocky hydroxyethylcellulose with HE-MS 1.7 achieves a 7-fold increase in tablet hardness as compared to regular Natrosol 250 HHX Pharm. The highly substituted blocky HEC (HE-MS 3.0) achieves a remarkable 12-fold increase in tablet strength. In the typical modified release formulation, these materials all showed excellent direct compression performance and drug release kinetics as compared to commercial Natrosol 250 HHX Pharm.

0106The data suggest that regions of unsubstituted cellulose backbone appear to be critical for improved HEC compactibility. In the case of the highly substituted, blocky HEC Example 19, the highly substituted ethylene oxide regions may act as a plasticizer resulting in extremely ductile material that is resistant to fracture. <tables id="tabl0029" num="0029"><table frame="all"><title><b>Table 16: Hardness of 99 wt% HEC with 1 wt% Stearic Acid Tablets</b></title><tgroup cols="6"><colspec colnum="1" colname="col1" colwidth="29mm" /><colspec colnum="2" colname="col2" colwidth="23mm" /><colspec colnum="3" colname="col3" colwidth="14mm" /><colspec colnum="4" colname="col4" colwidth="38mm" /><colspec colnum="5" colname="col5" colwidth="37mm" /><colspec colnum="6" colname="col6" colwidth="27mm" /><thead><row><entry align="center" valign="top">Designation</entry><entry align="center" valign="top">Process</entry><entry align="center" valign="top">HE-MS</entry><entry align="center" valign="top">1 wt% Solution Viscosity (cps)</entry><entry align="center" valign="top">Mean Particle Diameter (um)</entry><entry align="center" valign="top">Tablet Hardness (kP)</entry></row></thead><tbody><row><entry align="center">Invention Example 5</entry><entry align="center">C</entry><entry align="center">1.7</entry><entry align="center">14,400</entry><entry align="center">108</entry><entry align="center">23.3</entry></row><row><entry align="center">Counter Example 5C</entry><entry align="center">A</entry><entry align="center">1.6</entry><entry align="center">1,860</entry><entry align="center">105</entry><entry align="center">3.0</entry></row><row><entry align="center">Natrosol 250 HHX</entry><entry align="center">Commercial</entry><entry align="center">2.4</entry><entry align="center">3,950</entry><entry align="center">105</entry><entry align="center">2.7</entry></row><row><entry align="center">Invention Example 19</entry><entry align="center">B</entry><entry align="center">2.9</entry><entry align="center">2,640</entry><entry align="center">108</entry><entry align="center">47.3+</entry></row><row><entry align="center">Counter Example 19C</entry><entry align="center">A</entry><entry align="center">3.0</entry><entry align="center">2,980</entry><entry align="center">86</entry><entry align="center">4.0</entry></row></tbody></tgroup></table></tables>

0107While this invention has been described with respect to specific embodiments, it should be understood that these embodiments are not intended to be limiting and that many variations and modifications are possible without departing from the scope of the appended claims.