Cleaning compositions.

Technical Field

0001The subject matter of this invention relates to cleaning compositions which contain alkyl- or alkenyl-carboxylate materials, especially alkyl- or alkenyl-succinates, in combination with polyester soil-release agents, as performance boosting ingredients.

Background

0002The patent literature describes the use of alkyl- and alkenyl-succinates as surfactants: US 2.283.214; detergency boosters UK 1.293.753; in various liquid cleaners UK 1.528.171, US 4.277.378; builders US 2.462.758 and the like. See also US 3.784.486.

0003A variety of substituted succinates and "sulfur-succinates" are described for various similar uses; US 3.912.663, US 4.152.515 and US 3.725.286.

0004The use of various succinates in combination with certain detergency ingredients is also known; see EPO 79191 and EPO 70190, as well as German 32 05 791 and German 33 17 337.

0005Indeed, the use of carboxylate materials of various types in solid and liquid cleaners is well-known : see UK 1.514.276 for amine soap mixtures; UK 1.429.143 for zeolite/polycarboxylate mixtures: US 2.264.103 for citrate and other carboxylate plus soap mixtures; US 3.634.392 for polysaccharidic carboxylate detergency builders; US 3.898.187 for various sulfur-succinates in dishwashing detergents; and UK 1.400.898 for use with clay softeners.

0006Various polymers have been suggested for use in detergent compositions.

0007There is a continuing search for improved cleaning compositions of all types, and the present invention boosts the performance of such compositions as described more fully hereinafter.

0008It is a major advantage of the present invention that superior product performance is achieved by the proper, and heretofore unrecognized, combination of various known carboxylate ingredients with effective soil-release polymers.

0009All percentages, ratios or proportions of ingredients disclosed hereinafter are by weight, unless otherwise specified.

SUMMARY OF THE INVENTION.

0010The present invention relates to detergent compositions designed especially for laundering fabrics. Said compositions may be formulated in liquid, solid, or granular form; the liquid form is preferred and such liquid-form compositions are hereinafter referred to as "heavy-duty liquids" or "HDL's", since they are designed to remove even the "heaviest" soil loads from fabrics when used in a conventional laundering operation.

0011The fully-formulated laundry compositions herein comprise a conventional alkyl- or alkenyl-dicarboxylate detergency builder (typically 1 % - 35 %; preferably 5 % - 20 %) conventional anionic, nonionic, cationic or zwitterionic detersive surfactants (typically 1 % - 35 %; preferably 5 % - 20 %) and, optionally, conventional detersive adjunct and carrier materials, and are characterized in that they contain at least 0.01 %, preferably 0.075 % to 5 %, most preferably 0.1 % to 1.5 %, of a soil-release polymer which is an alkoxylated ester of phthalic acid, as described more fully, hereinafter.

0012In a method aspect, the invention comprises a method for laundering fabrics by agitating said fabrics in an aqueous laundering liquor, said liquor containing at least 0.05 % by weight of a composition of the foregoing type.

0013Laundry additive-type products which comprise a mixture of the aforesaid builder and soil-release polymer (generally, at a ratio of 100:1 to 1:100, preferably a ratio of builder to soil-release polymer of at least 5:1) are also contemplated by this invention. Such compositions are designed to be used in combination with conventional, commercial laundry detergents.

DETAILED DESCRIPTION OF THE INVENTION

0014The essential components of the present compositions are the di-carboxylate builder and the soil release polymer. The detersive surfactants, optional detersive adjunct ingredients, as well as the carriers, fillers, etc., are all well-known to workers in this field.

0015The detergent compositions herein are preferably formulated as heavy duty liquids, but may also be formulated in solid forms as flakes, chips, powders, bars or spray-dried granules.

0016The detergent additive compositions may be in any of the foregoing forms.

0017Articles which comprise the detergent compositions or the laundry additive compositions releasably-affixed to a sheet substrate or releasably-contained in a sachet or pouch in pre-measured form, suitable for use in an aqueous laundry bath, are also contemplated by this invention.

0018Dicarboxylate Builder : The preferred builders herein are of the general formula R-CH(COOH)CH₂(COCH) i.e. derivatives of succinic acid, wherein R is C₁₀-C₂₀ alkyl or alkenyl, preferably C₁₂-C₁₆, or wherein R may be substituted with hydroxyl, sulfo, sulfoxy or sulfone substituents, all as described in the above-mentioned patents.

0019The succinate builders are preferably used in the form of their water-soluble salts, including the sodium, potassium, ammonium and alkanolammonium salts.

0020Specific examples of succinate builders include: lauryl succinate, myristyl succinate, palmityl succinate, 2-dodecenyl succinate (preferred), 2-pentadecenyl succinate, and the like.

0021Soil-Release Polymer : The soil release polymer used herein is of a very special type, and has the generic formula: <chemistry id="chem0001" num="0001"><img file="EP0201124A2_D0001.tif" /></chemistry>in which X can be any suitable capping group, with each X being selected from the group consisting of H, and alkyl or acyl groups containing from 1 to about4 carbon atoms. n is selected for water solubility and generally is from about 6 to about 120, preferably from about 10 to about 50. u is critical to formulation in a liquid detergent having a relatively high ionic strength. There should be very little material in which u is greater than 5. Furthermore there should be at least 20 %, preferably at least 40 % of material in which u ranges from 3 to 5.

0022The _R¹ moieties are essentially 1,4-phenylene moieties. As used herein, the term "the R¹ moieties are essentially 1,4-phenylene moieties" refers to compounds where the R¹ moieties consist entirely of 1,4-phenylene moieties, or are partially substituted with other arylene or alkarylene moieties, alkylene moieties, alkenylene moieties, or mixtures thereof. Arylene and alkarylene moieties which can be partially substituted for 1,4-phenylene include 1,3-phenylene, 1,2-phenylene, 1,8-naphthylene, 1,4-naphthylene, 2,2-biphenylene, 4,4-biphenylene and mixtures thereof. Alkylene and alkenylene moieties which can be partially substituted include ethylene, 1,2-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexamethylene, 1,7-heptamethylene, 1,8-octamethylene, 1,4-cyclohexylene, and mixtures thereof.

0023For the R¹ moieties, the degree of partial substitution with moieties other than 1,4-phenylene should be such that the soil release properties of the compound are not adversely affected to any great extent. Generally, the degree of partial substitution which can be tolerated will depend upon the backbone length of the compound, i.e., longer backbones can have greater partial substitution for 1,4-phenylene moieties. Usually, compounds where the R comprise from about 50 to 100 % 1,4-phenylene moieties (from 0 to about 50 % moieties other than 1,4-phenylene) have adequate soil release activity. For example, polyesters made according to the present invention with a 40:60 mole ratio of isophthalic (1,3-phenylene) to terephthalic (1,4-phenylene) acid have adequate soil release activity. However, because most polyesters used in fiber making comprise ethylene terephthalate units, it is usually desirable to minimize the degree of partial substitution with moieties other than 1,4-phenylene for best soil release activity. Preferably, the R moieties consist entirely of (i.e., comprise 100 %) 1,4-phenylene moieties, i.e. each R¹ moiety is 1,4-phenylene. (Irrespective of the mechanism of action, it is surprising that the soil release polymers do show excellent benefits on fabrics other than polyester fabrics and the compositions herein are designed to clean all manner of fabrics and textiles.)

0024For the R² moieties, suitable ethylene or substituted ethylene moieties include ethylene, 1,2-propylene, 1,2-butylene, 1,2-hexylene,3-methoxy-1,2-propylene and mixtures thereof. Preferably, the R 2 moieties are essentially ethylene moieties, 1,2-propylene moieties or mixtures thereof. Inclusion of a greater percentage of ethylene moieties tends to improve the soil release activity of the compounds. Surprisingly, inclusion of a greater percentage of 1,2-propylene moieties tends to improve the water solubility of the compounds.

0025For this invention, the use of 1,2-propylene moieties or a similar branched equivalent is essential for incorporation of any substantial part of the soil release component in the heavy duty liquid detergent compositions. Preferably, from about 75 % to about 100 %, more preferably from about 90 % to about 100 % of the R moieties are 1,2-propylene moieties.

0026The value for each n is at least about 6, but is preferably at least about 10. The value for each n usually ranges from about 12 to about 113. Typically, the value for each n is in the range of from about 12 to about 43.

0027A preferred process for making the preferred soil release component comprises the step of extracting a polymer having a normal distribution in which a substantial portion comprises a material in which u is greater than 6 with essentially anhydrous ethanol at low temperatures, e.g. from about 10°C to about 15°C. The ethanol soluble fraction is substantially free of the longer polymers and is much easier to formulate into isotropic heavy duty liquids, especially those with higher ionic strengths, e.g. more than about 10 % of the succinate builder.

0028Although the polymers wherein u is less than about 3 are essentially of no value in providing soil release effects, they seem to importantly affect the overall product performance. In particular, the grease-removal performance of compositions containing succinate builders can be sub-optimal; whereas when soil-release polymers are present, this performance is restored to more acceptable levels.

0029Detersive Surfactants - The detergent compositions of this invention will contain organic surface-active agents ("surfactants") to provide the usual cleaning benefits associated with the use of such materials.

0030Detersive surfactants useful herein include well-known synthetic anionic, nonionic, amphoteric and zwitterionic surfactants. Typical of these are the alkyl benzene sulfonates, alkyl- and alkylether sulfates, paraffin sulfonates, olefin sulfonates, amine oxides, alpha-sulfonates of fatty acids and of fatty acid esters, ethoxylated alcohols and ethoxylated alkyl phenols, and the like, which are well-known from the detergency art. In general, such detersive surfactants contain an alkyl group in the C₉-C₁₈ range; the anionic detersive surfactants can be used in the form of their sodium, potassium or triethanolamnonium salts. Standard texts such as the McCutcheon's Index contain detailed listings of such typical detersive surfactants. C₁₁-C₁₄ alkyl benzene sulfonates, C₁₂-C_1B paraffin-sulfonates and C₁₁-C₁₈ alkyl sulfates are especially preferred in the compositions of the present type.

0031Also useful herein are the water-soluble soaps, e.g. the common sodium and potassium coconut or tallow soaps well-known in the art.

0032The surfactant component can comprise as little as 1 % of the laundry detergent compositions herein, but generally the compositions will contain 5 % to 40 %, preferably 6 % to 30 %, of surfactant. Mixtures of the anionics, such as the alkyl benzene sulfonates, alkyl sulfates and paraffin sulfonates, with C9-C16 ethoxylated alcohol surfactants are preferred for through-the-wash cleansing of a broad spectrum of soils and stains from fabric.

0033Detersive Adjuncts - The compositions herein can contain other ingredients which aid in their cleaning performance. For example, it is highly preferred that the laundry compositions herein also contain enzymes to enhance their through-the-wash cleaning performance on a variety of soils and stains. Amylase and protease enzymes suitable for use in detergents are well-known in the art and in commercially available liquid and granular detergents. Commercial detersive enzymes (preferably a mixture of amylase and protease) are typically used at levels of 0.001 % to 2 %, and higher, in the present compositions.

0034Moreover, the compositions herein can contain, in addition to ingredients already mentioned, various other optional ingredients typically used in commercial products to provide aesthetic or additional product performance benefits. Typical ingredients include pH regulants, perfumes, dyes, bleaches, optical brighteners, soil suspending agents, hydrotropes and gel-control agents, freeze-thaw stabilizers, bactericides, preservatives, suds control agents, bleach activators and the like.

0035In a through-the-wash laundry mode, the compositions are typically used at a concentration of at least 500 ppm, preferably 0.10 % to 2.5 %, in an aqueous laundry bath at pH 7-11 to launder fabrics. The laundering can be carried out by agitating fabrics with the present compositions over the range from 5°C to the boil, with excellent results.

INDUSTRIAL APPLICATION

0036The following examples are typical of the preferred compositions of this invention, but are not intended to limit the scope of the invention.

EXAMPLE I

0037A preferred HDL is as follows: <tables id="tabl0001" num="0001"><img file="EP0201124A2_D0002.tif" /></tables><ul id="ul0001" list-style="none"><li>^* Prepared by esterifying 1,4 phthalic acid (chloride) with 1,2-propane diol and ethoxylating the polymer with ethylene oxide. The resulting polymer mix is fractionated in cold (15°C) ethanol to provide a cold-ethanol soluble fraction having a u value predominately in the 3 to 5 range. Average ethoxylation value (n) ranges from 12-43.</li><li>^** Viscosity may be modified by replacing some of the NaOH with KOH, according to the desires of the formulator. A stable homogeneous isotropic product is secured.</li></ul>

0038It has been discovered that diluting the composition of Example I with water rapidly reduces its viscosity. This is in direct contrast with many HDL's, whose viscosity increases when water is added. The rapid reduction in viscosity upon addition of water helps the HDL compositions of this invention avoid the problem of dispenser clogging in automatic washing machines or other laundry detergent dispensers.

EXAMPLE II

0039A laundry additive product is prepared by admixing 15 grams of lauryl succinate with 1 gram of the soil release polymer of Example I. The composition is placed in a flexible polyethylene bag which is sealed along one edge with water-soluble polyvinyl alcohol adhesive. In use, the pouch is simply dropped into an aqueous laundry liquor, together with any conventional laundry detergent, to provide additional builder and soil-release benefits, including the removal of clay and particulate soils from cotton and polyester fabrics.

EXAMPLE III

0040A granular detergent composition comprises the following ingredients: <tables id="tabl0002" num="0002"><img file="EP0201124A2_D0003.tif" /></tables>

0041An aqueous crutcher mix is prepared and spray-dried.

0042The Enzyme Mix, Soil Release Polymer and TAED bleach activator are dry-mixed with the resulting granules.