Polyurethane dispersion (pud) with improved isopropanol resistance, flexibility and softness

ES 2 335 892 T3

DESCRIPTION

Polyurethane dispersion (PUD) with improved isopropanol resistance, flexibility and softness.

Background of the invention

The invention relates to aqueous dispersions comprising isocyanate functional polyurethane prepolymers and the use thereof in the production of flat materials.

In the early 1990s, global prophylactic measures against HIV, Hepatitis B and Hepatitis C led to a dramatic increase in the use of condoms and latex gloves. Approximately 1% of glove users and approximately 10% of users working in the healthcare field showed hypersensitivity reactions and this has led to a significant increase in the importance of finding alternative materials for the glove sectors in recent years. test kit and condoms.

Natural latex contains type I and type IV allergens. Type I allergens are attributed to proteins naturally present in latex and can even cause anaphylactic shock. Type IV allergens are the necessary accelerators and additives for the production of latex. This often leads to hypersensitivity-mediated contact dermatitis. Polyurethanes are not known to cause the allergic reactions described. Therefore, there is a pressing need for aqueous polyurethane dispersions that can be processed in a manner analogous to rubber latex to obtain the aforementioned sanitary articles.

According to the teachings of WO-A00 / 61651, aqueous polyurethane dispersions obtained from nonionic isocyanate prepolymers after the addition of anionic emulsifiers and their subsequent dispersion with water are suitable for the production of gloves and condoms. However, a disadvantage of these products is the use of anionic emulsifiers, which can migrate into the polymer during use, with the consequent negative effect on the characteristics of use. The same limitations apply to the products obtainable according to the teachings of WO-A00 / 61653.

A big problem when using polyurethane gloves in medicine, and specifically in surgery, is the use in these applications of mixtures containing isopropanol to sterilize gloved hands. The use of isopropanol causes the glove material to swell, which greatly reduces the mechanical resistance of the material, causing the gloves to tear.

US Patent 5,997,969 describes a way to improve the isopropanol resistance of standard commercial polyurethane dispersions by the subsequent addition of crosslinking components. However, the addition of a crosslinking component is a very technically demanding and expensive process for the manufacture of gloves and condoms, because the mixing devices necessary for this purpose are not normally available. Such crosslinking agent and substrate mixtures have only a limited shelf life. This is also a problem for glove and condom manufacturers for which there may not be a simple solution, because the processing is generally post-coagulation, and coagulation batches are generally not used. They are usually filled repeatedly with new material.

European Patent 741,152 discloses NCO-functional polyurethane ("PU") prepolymers based on a polyol component comprising primarily polyoxypropylene diols having a low content of unsaturated units. Dispersions prepared therefrom are suitable for the production of flexible films and coatings. However, it is disadvantageous that PU films have unsatisfactory resistance to solvents.

Canadian Patent 1,089,141 describes mixtures of aromatic and aliphatic or cycloaliphatic polyisocyanates for the preparation of stable, finely divided aqueous dispersions of anionically modified polyurethanes. However, the isopropanol resistance of flat materials that can be produced therefrom is also poor.

US Application Serial Number 10 / 453,755, filed June 3, 2003, describes various additional literature that addresses the use of polyurethane dispersions for medical applications. The inventions described in application 10 / 453,755 are isocyanate functional prepolymers, aqueous dispersions of polyurethanes produced from the prepolymers and various medical uses of such dispersions. The prepolymers described therein have an NCO content of from about 1 to about 6% by weight, and are prepared by reacting:

A) an organic diisocyanate,

B) at least one compound with dihydroxy groups having a number average molecular weight of from about 700 to about 16,000, and

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C) a trihydroxy component of formula:

R- (OH)₃ wherein R is a saturated straight chain or branched chain aliphatic group of 2 to 8 carbon atoms, and wherein the amount of component C) is such that the hydroxy groups of component C) amount from about 2 to about 15% based on the total amount of hydroxy equivalents used to produce the prepolymer.

Description of the invention

The object of the present invention was to provide aqueous polyurethane dispersions comprising prepolymers with functional NCO groups suitable for the production of flat polyurethane materials that combine satisfactory solvent resistance simultaneously with good minimal tear resistance and good minimal elongation to break. and that they do not have the disadvantages described in the prior art.

The present invention provides a polyurethane prepolymer that is prepared from a combination of specific isocyanates and specific hydroxyl group-containing compounds satisfying specified criteria that achieve this goal.

More specifically, the present invention relates to aqueous polyurethane dispersions produced from isocyanate functional prepolymers and to various uses of such dispersions. The polyurethane prepolymer has an NCO content of about 1 to about 6% by weight (and preferably 2 to 4%), and is prepared by reacting:

a) a mixture of isocyanates comprising:

i) from 5 to 50% by weight of an aliphatic and / or cycloaliphatic isocyanate, and ii) from 50 to 95% by weight of an aromatic diisocyanate,

b) a di- or polyhydroxy compound having a number average molecular weight of 700 to 16,000, and

c) optionally, a dihydroxy and / or polyhydroxy compound having a number average molecular weight of less than 700, provided that

1) at least one of the components a), b) or c) has a functionality greater than 2 and

2) if both components a) and b) are difunctional, component c) cannot be a trihydroxy component of the formula:

R- (OH)₃ wherein R is a saturated straight chain or branched chain aliphatic group of 2 to 8 carbon atoms.

Suitable isocyanates include any organic component that has at least two free isocyanate groups per molecule, such as, for example, X-diisocyanates (NCO)₂, with X representing a bivalent aliphatic hydrocarbon radical having 4 to 12 carbon atoms, a bivalent cycloaliphatic hydrocarbon radical having 6 to 15 carbon atoms, a divalent aromatic hydrocarbon radical having 6 to 15 carbon atoms, or a divalent araliphatic hydrocarbon radical having 7 to 15 carbon atoms. Additional examples of compounds that can be used as a diisocyanate component are described, for example, by W. Siefken in Justus Liebig's Annalen der Chemie, 562, p. 75-136.

Specific examples of useful diisocyanates are tetramethylene diisocyanate, methylpentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 1-isocyanate-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane, 4 , 4'-diisocyanatobenzene, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanatodiphenylmethane, 2,2'- and 2,4'-diisocyanatodiphenylmethane, p-xylylene diisocyanate, p-isopropylidene diisocyanate, 1,3- and 1,4-diisocyanatomethylbenzene, as well as mixtures of these compounds.

Particularly preferable are: 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane; 1,6-hexamethylene diisocyanate; 4,4'-diisocyanatodicyclohexylmethane; 2,4- and 2,6-diisocyanatotoluene or any mixture of these isomers; 4,4'-, 2,4'- and 2,2'-diisocyanatodiphenylmethane (MDI monomers) or any mixture of these isomers.

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Also useful are the so-called polymeric MDI products as obtained by aniline-formaldehyde condensation followed by phosgenation (crude MDI), as well as the polymeric MDI products that can be obtained therefrom by partial removal of the MDI monomers. by distillation.

Of course, it is also possible to use (jointly use) small amounts of polyisocyanates of higher functionality which are known in polyurethane chemistry and modified polyisocyanates having, for example, carbodiimide groups, allophanate groups, isocyanurate groups, urethane groups and / or groups. biuret.

In a preferred embodiment, the isocyanate is a mixture comprising 10 to 45% by weight, preferably 20 to 35% by weight, of aliphatic and / or cycloaliphatic isocyanate (s) and 55 to 90 % by weight, preferably 65 to 80% by weight, of aromatic diisocyanate (s).

Suitable components b) are compounds having at least two hydroxyl groups and having a number average molecular weight of 700 to 16,000. Examples of such compounds are polyethers, polyesters, polycarbonates, polylactones, and polyamides. Preferred compounds have 2 to 8, more preferably 2 to 4, hydroxyl groups, as known in the preparation of homogeneous and cellular polyurethanes and as described, for example, in German patent 2,832,253, pages 11 to 18. Mixtures of various such compounds can also be used.

Linear polyester diols or also low-branched polyester polyols are considered suitable as polyester polyol (s), which can be prepared in a known way from aliphatic, cycloaliphatic or aromatic dicarboxylic or polycarboxylic acids or anhydrides thereof ( for example, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, nonanodicarboxylic, decanedicarboxylic, terephthalic, isophthalic, o-phthalic, tetrahydrophthalic, hexahydrophthalic or trimellitic) as well as acid anhydrides (such as o-phthalic, trimellitic or succinic anhydride or a mixture thereof) with polyhydric alcohols such as, for example, ethanediol, diethylene, triethylene, tetraethylene glycol, 1,2 -propanediol, dipropylene, tripropylene, tetrapropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl -1,3-propanediol, 1,4-dihydroxycyclohexane, 1,4-dimethylolcyclohexane, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol or mixtures thereof, optionally with the simultaneous use of higher functional polyols such as trimethylolpropane or glycerol. Of course, cycloaliphatic and / or aromatic dihydroxy and polyhydroxy compounds such as polyhydric alcohol (s) are also suitable for the preparation of polyester polyol (s). Instead of the free polycarboxylic acid, the corresponding polycarboxylic acid anhydrides or the corresponding polycarboxylic acid esters with lower alcohols or mixtures thereof can be used for the preparation of the polyesters.

Polyester polyols can also be homopolymers or copolymers of lactones, which are preferably obtained by addition reactions of lactones or mixtures of lactones, such as butyrolactone, ε-caprolactone and / or methyl-s-caprolactone with difunctional initiator molecules and / or of suitable higher functionality such as, for example, the low molecular weight polyhydric alcohols mentioned above as structural components for polyester polyols. The corresponding polymers of ε-caprolactone are preferable.

Polycarbonates having hydroxyl groups are also considered to be suitable polyhydroxy components. They can be prepared by reacting diol (s) such as 1,4-butanediol and / or 1,6-hexanediol with diaryl carbonate (s), for example diphenyl carbonate, dialkyl carbonates or phosgene.

The polyaddition products of styrene oxides, and ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide and epichlorohydrin, as well as their co-addition and graft products, as well as the polyether polyols obtained by condensation of alcohols Polyhydric or mixtures thereof and polyether polyols obtained by alkoxylation of polyhydric alcohols, amines and amino alcohols, are examples of suitable polyether polyol (s).

Preferred components b) are the homopolymers, copolymers and graft polymers of propylene oxide and ethylene oxide, which are obtained by addition reactions of so-called epoxides with low molecular weight diols or triols, as mentioned above as components. to produce polyether polyols, or with low molecular weight polyols with higher functionality such as, for example, pentaerythritol or sugar, or with water.

Especially preferable components b) are polyether polyols based on one or more polyoxypropylene diols having number average molecular weights of from about 1000 to about 8000 and having an unsaturated end group content less than or equal to 0.02 milliequivalents, preferably from 0.005 to 0.015 milliequivalents, (procedure used for ASTM D2849-69 determination) per gram of polyol, which are obtained by known processes by double metal cyanide complex catalyzed (DMC catalyzed) polymerization of alkylene oxides, preferably polypropylene oxides, as described, for example, in US patent 5,158,922 (for example, Example 30 ) or in European patent 654,302 (from page 5, line 26 to page 6, line 32). Particularly preferable components b) are the compounds listed in Table 1 below.

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TABLE 1

<td>Polyol</td><td>Acclaim® 2200 N</td><td>Acclaim® 4200 N</td><td>Acclaim® 8200</td><td>Acclaim® 6300</td><td>Acclaim® 3201</td>

<td>Physical data</td><td></td><td></td><td></td><td></td><td></td>

<td>Molecular weight</td><td> 2000</td><td> 4000</td><td> 8000</td><td> 6000</td><td> 3000</td>

<td>Functionality</td><td> 2</td><td> 2</td><td> 2</td><td> 3</td><td> 2</td>

<td>Viscosity (20 ° C)</td><td> 465</td><td> 1225</td><td> 4215</td><td> 1900</td><td> 775</td>

<td>Chemical data</td><td></td><td></td><td></td><td></td><td></td>

<td>OH value (mg KOH / g)</td><td> 56</td><td> 28</td><td> 14</td><td> 28</td><td> 37</td>

<td>Content of double bonds (milliequiv./g)</td><td>link &lt;0.0070</td><td> &lt; 0,0070</td><td> &lt; 0,0070</td><td> &lt; 0,0070</td><td> &lt; 0,0070</td>

<td>Acid value (mg KOH / g) KOH / g)</td><td> 0,02</td><td> 0,018</td><td> 0,02</td><td> 0,02</td><td> 0,018</td>

<td colspan="6">All Acclaim® polyol products are commercially available from Bayer AG, Leverkusen, Germany.</td>

In a preferred embodiment of the present invention, component b) comprises at least 60% by weight of at least one polyoxypropylene glycol.

Suitable components c) are di and / or polyhydroxy compounds having number average molecular weights from 62 to less than 700. The polyhydric alcohols, in particular dihydric alcohols, mentioned for the preparation of polyether polyols, as well as polyether diols and triols and polyester diols which have the required molecular weight. Suitable low molecular weight polyesters include, for example, bis- (hydroxyethyl) esters of adipic acid. Also useful are short chain co-addition and homo-addition products of ethylene oxide or propylene oxide, initiated with aromatic diols. Preferred components c) are i) the low molecular weight diols 1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol and 2,2-dimethyl-1,3-propanediol, with 1,4- butanediol and 1,6-hexanediol, and ii) low molecular weight polyether triols.

Also useful are the addition products of alkylene oxides, such as, for example, propylene oxide and ethylene oxide, with aromatic dihydroxy compounds or aromatic dicarboxylic acids such as, for example, hydroquinone, resorcinol, pyrocatechol or 2,2- bis (4-hydroxyphenyl) propane (bisphenol A).

The present invention also provides a process for the preparation of prepolymers according to the invention having isocyanate groups in which components a), b) and c) are reacted in a proportion such that the isocyanate content is 1 to 6% in weight and preferably 2 to 4% by weight.

Generally, the proportion of the components is such that the mathematical number average isocyanate functionality of the resulting prepolymer (s) is between 2.1 and 3.6 and preferably between 2.3 and 2.8. The preparation takes place in the temperature range of 20 to 130 ° C, preferably between 50 and 120 ° C, more preferably between 70 and 105 ° C.

The prepolymer according to the invention is then transformed into an aqueous dispersion. To this end, the prepolymer according to the invention is reacted with:

B) compounds that comprise an anionic or potentially anionic group and two groups that are reactive with isocyanate groups and

C) at least one chain extender having two amine groups that are reactive with isocyanate groups.

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Suitable components B) are compounds that include an anionic group or a group that enables the formation of anionic groups (potentially anionic group) and two groups that are reactive with isocyanate groups, such as, for example, diamine compounds that comprise as the group anionic a carboxylate group or a sulfonate group or, as the potentially anionic group, a carboxylic acid group or a sulfonic acid group. Preferable components B) are diamines or polyamines comprising alkali metal sulfonate groups, such as, for example, the alkali metal salts of N- (2-aminoethyl) -2-aminoethanesulfonic acid. Sodium salt is especially preferable.

Free carboxylic acids or sulfonic acids can, of course, also be incorporated into the isocyanate polyaddition process. These must be neutralized with neutralizing agents such as, for example, alkali metal hydroxides, alkali metal hydrogen carbonates, alkali metal carbonates or tertiary amines such as, for example, triethylamine, diisopropylethylamine, triisopropylamine, N, N-dimethylethanolamine, triethanolamine or triisopropanolamine, prior to conversion of the polyurethane resin (s) to water.

Suitable compounds as chain extenders C) are primary and / or secondary aliphatic and / or alicyclic diamines such as, for example, 1,2-ethanediamine, 1,6-hexamethylenediamine, 1-amino-3,3,5-trimethyl- 5-aminomethylcyclohexane (isophorone diamine), piperazine, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, adipic acid dihydrazide or hydrazine. Polyether diamines, which can be prepared by reacting the corresponding polyether diols with ammonia and / or primary amines, are also useful. However, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (isophorone diamine) and 1,2-ethanediamine are especially preferable as the E chain extenders).

The aqueous preparations of polyurethane resins, on which the dispersions according to the invention are based, can generally be prepared by a process that is described by D. Dieterich in Houben-Weyl: Methoden der Organischen Chemie, Vol. E20, p. 1670-1681 (1987). The so-called "acetone process" is preferable. In this process the aqueous preparations on which the dispersions are based, which comprise the prepolymers according to the invention, are synthesized in a multi-stage process.

In the first stage, the prepolymer according to the invention is dissolved in an organic solvent, at least partially miscible in water, which does not have reactive isocyanate groups. The preferable solvent is acetone. However, other solvents, such as, for example, 2-butanone, tetrahydrofuran, dioxane, N-methylformamide, N-methylacetamide or N-methylpyrrolidone can also be used either as such or included in small amounts. The amounts are generally such that a solids content of 20 to 80% by weight is produced, preferably 30 to 50% by weight.

The prepolymer solution is then reacted with a mixture (s) of the amino functional components B) and component C), preferably dissolved in one of the above-mentioned solvents or in water, with chain extension, to obtain the high molecular weight polyurethane resin. The amounts of the components are such that 0.3 to 0.93, preferably 0.65 to 0.85 moles of NH groups are present₂ of components B) and C) per mole of isocyanate groups of the dissolved prepolymer. Component B) containing an anionic group or a group that enables the formation of anionic groups should, furthermore, be used in such amounts that 19 to 70 meq are present. of ions per 100 g of solids, preferably 20 to 35 meq. of ions per 100 g of solids, in the resulting polyurethane.

When using components B) having a free carboxylic acid group or a sulfonic acid group, the acid groups are neutralized with a neutralizing agent before the addition of the water necessary for the dispersion, in a proportion of 50 to 100 equivalents in%, with respect to the free acid groups.

The high molecular weight polyurethane resin precipitates as a finely divided dispersion by adding water to the solution. The organic solvent can optionally be fully or partially distilled under reduced pressure. The amount of water is such that the resulting aqueous dispersions comprise 30 to 60% by weight, preferably 35 to 50%, by weight of solids.

The aqueous dispersions of the invention have a mean particle diameter (measured by laser correlation spectroscopy) of 50 to 300 nm, preferably 60 to 150 nm, and are stable in storage for at least 6 months.

The dispersions of the invention can be processed by conventional procedures to obtain films, sheets, surface coatings, coatings, finishes and for the impregnation of the most varied substrates. The dispersions are preferably suitable for the production of films, more preferably for the manufacture of gloves and polyurethane condoms by the dipping process or coagulation process.

The invention provides polyurethane films that are resistant to isopropanol. The use of the prepolymers according to the invention is preferable for the manufacture of polyurethane gloves and condoms.

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The polyurethane dispersions of the invention may also, depending on the intended use, contain conventional auxiliary agents and additives, such as, for example, crosslinking agents, plasticizers, pigments, defoaming agents, feel-enhancing additives or fillers.

It is also possible to combine the aqueous dispersions of the invention with other dispersions such as, for example, polyacrylate dispersions, natural and synthetic rubber networks such as, for example, NBR (nitrile-butadiene rubber), chloroprene or other homopolymers and copolymers such as, for example, ethyl vinyl acetate or ethyl vinyl alcohol.

Flat materials produced from the polyurethane dispersions of the present invention have satisfactory solvent resistance while having good minimal tear resistance and good minimal elongation to break.

The invention is further illustrated by, but not intended to be limited by, the following examples, in which all parts and percentages are by weight, unless otherwise indicated.

Examples

Examples 1 to 5

General indications for the production of polyurethane dispersion films or

The aqueous dispersions are applied to a glass plate by means of a 1000 Pm scalpel, and should not have bubbles or foam. Coatings are pre-dried at room temperature for 16 to 24 hours. The clear films are subsequently dried in a circulating air drying cabinet at 80 ° C for 1 hour. The films are left at room temperature for at least 5 hours. After removal of the films from the glass plate, the test samples that are required in each case are cut from the films.

Determination of the resistance to alcohols of polyurethane dispersion films

Dimensions of test specimens, in mm

Overall length: 75.0

Head width: 12.5

Band Length: 25.0

Band width: 4.0

Thickness:

approx. 0.2

The test samples were stored at room temperature for 24 hours. They were then scored to the right and left of the band at a distance of about 50 mm and elongated 100% and clamped in this state. The test sample under tension was moistened in the center of the two marks with 2 drops of isopropanol. If the sample broke, it was not resistant to alcohol.

The particle size was determined by laser correlation spectroscopy (measuring instrument: Malvern Instruments Zetasizer 1000).

Example 1 (Comparative Example) corresponds to Example 1 of Canadian Patent 1,089,141

203 g of a polyester prepared from adipic acid, hexanediol and neopentyl glycol, with an OH value of 55 mg of KOH / g, were dehydrated at 110 to 120 ° C and at 30 mbar for 30 minutes. The polyester was cooled and dissolved in 200 g of acetone and 40.5 g of 1,4-butanediol was added. A mixture of 69.7 g of toluene diisocyanate (ratio of isomers 2.4 / 2.6 = 80/20) and 69.7 g of hexamethylene diisocyanate, as well as 0.02 g of dibutyltin dilaurate were then added. . After stirring at 60 ° C for 3 hours, the batch was diluted in 300 g of acetone and cooled to room temperature. 19.3 g of a 40% aqueous solution of the equimolar addition product of ethylenediamine and sodium acrylate were added and stirred into the solution of the prepolymer thus obtained. After 20 minutes, 500 g of water was added dropwise and the acetone was then distilled off under reduced pressure. A very finely divided stable dispersion was produced.

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The flat PU materials produced from this dispersion tore when treated with isopropanol, thus showing no resistance to alcohol.

Ion content [meq./100 g] = 14.3

Used components

Acclaim® 2200N, 4200N, 6300 and PPG 1000 polyols, as well as Desmophen® V 218 polyol, which are commercially available from Bayer AG, Leverkusen, Germany.

1.

TABLE 2

Polyol components

<td>Polyol</td><td>OH value (mg KOH / g)</td><td>Double bond content [meq./g]</td><td>Initiator</td>

<td>Acclaim® 2200N</td><td> 56</td><td> &lt; 0,0070</td><td>1,2-propylene glycol</td>

<td>Acclaim® 4200N</td><td> 28</td><td> &lt; 0,0070</td><td>1,2-propylene glycol</td>

<td>Acclaim® 6300</td><td> 28</td><td> &lt; 0,0070</td><td>glycerol</td>

<td>Acclaim® PPG 1000</td><td> 112</td><td>approx. 0</td><td>1,2-propylene glycol</td>

<td>Desmophen® V 218</td><td> 245</td><td>approx. 0</td><td>glycerol</td>

2. Isocyanate components:

Toluene diisocyanate, TDI 80: Isomer ratio 2.4 / 2.6 = 80/20, NCO functionality = 2

1-isocyanate-5- (isocyanatomethyl) -1,3,3-trimethylcyclohexane: IPDI, isophorone diisocyanate

Other ingredients AAA salt: sodium salt of N-2-aminoethane-2-aminoethanesulfonic acid, 45% in water of 1,4-butanediolethylenediamine water

Example 2 (According to the invention)

<td>446.4 g</td><td>Acclaim® 2200N polyol</td>

<td>167.0g</td><td>Acclaim® 6300 polyol</td>

<td>26.1 g</td><td>1,4-butanediol</td>

<td>39.4 g</td><td>1 -¡ocyanate-5- (¡soc¡anatome¡l) -1,3,3-trimethylcyclohexane (IPDI)</td>

<td>115.6g</td><td>Toluene diisocyanate (TDI 80)</td>

<td>1770.0 g</td><td>acetone</td>

<td>75.6 g</td><td>AAA salt</td>

<td>0.4 g</td><td>ethylenediamine</td>

<td>1640.0 g</td><td>partially deionized water</td>

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A mixture of 446.4 g of Acclaim® 2200 N polyol and 167.0 g of Acclaim® 6300 polyol was dehydrated at 110 to 120 ° C and 30 to 50 mbar for 1 hour. The mixture was cooled to 90 ° C and stirred with 26.1 g of 1,4-butanediol for 5 minutes, then 39.4 g of IPDI and 115.6 g of TDI 80 were added. After stirring at 95 to 105 ° C for 7 hours, a prepolymer with isocyanate end groups was obtained with an isocyanate (NCO) content of 3.04% (theoretical NCO = 3.04%). The prepolymer was cooled to about 60 ° C and 1770 g of acetone was added with stirring. An amine chain extender solution prepared from 75.6 g of AAA salt and 0.4 g of ethylenediamine was added at about 50 ° C to the clear, homogeneous prepolymer solution. The solution thus became cloudy and the viscosity increased slightly. After 15 minutes, 1640 g of partially deionized water was added over 30 seconds, with rapid stirring. After about 200 ml of water, a low viscosity dispersion was formed. The acetone was then distilled off under vacuum induced by water jet at 50 ° C.

A finely divided stable dispersion with a mean particle size of 84 nm was obtained. The dispersion had a solids content of 33.6% and a Ford cup viscosity value (4mm nozzle) of 18 seconds at 25 ° C.

Films were prepared from the dispersions on a glass plate with a scalpel. These films were dried first at room temperature and then in a circulating air drying cabinet for 1 hour at 80 ° C.

The resulting films were clear and elastic and resistant to isopropanol.

Ion content [meq./100 g] = 21.6

Example 3 (According to the invention)

<td>216.2 g</td><td>Acclaim® 2200N polyol</td>

<td>445.4 g</td><td>PPG 1000</td>

<td>23.5 g</td><td>Desmophen® V 218 polyol</td>

<td>43.5 g</td><td>1-isocyanate-5- (socyanatomethyl) -1,3,3-trimethylcyclohexane (IPDI)</td>

<td>125.4g</td><td>Toluene diisocyanate (TDI 80)</td>

<td>1653.0 g</td><td>acetone</td>

<td>76.1 g</td><td>AAA salt</td>

<td>0.3 g</td><td>ethylenediamine</td>

<td>1826.0 g</td><td>partially deionized water</td>

A mixture of 216.2 g of Acclaim® 2200 N polyol, 445.4 g of PPG 1000 and 23.5 g of Desmophen® V 218 polyol was dehydrated at 110 to 120 ° C and 30 to 50 mbar for 1 hour . The mixture was then cooled to 90 ° C and 43.5 g of IPDI and 125.4 g of TDI 80 were added. After stirring at 95 to 105 ° C for about 7 hours, a prepolymer with isocyanate end groups was obtained with an isocyanate (NCO) content of 2.89% (theoretical NCO = 3.08%). The prepolymer was cooled to about 60 ° C and 1653 g of acetone was added with stirring. An amine chain extender solution prepared from 76.1 g of AAA salt and 0.3 g of ethylenediamine in 114 g of water at about 50 ° C was added to the clear, homogeneous prepolymer solution. The solution thus became cloudy and the viscosity increased slightly. After 15 minutes, 1.826 g of partially deionized water was added over 30 seconds, with rapid stirring. After about 200 ml of water, a low viscosity dispersion was formed. The acetone was then distilled off under vacuum induced by water jet at 50 ° C.

A finely divided stable dispersion was produced with a mean particle size of 65 nm. The dispersion had a solids content of 33.8% and a Ford cup viscosity value (4mm nozzle) of 48 seconds at 25 ° C.

Film products with this dispersion were prepared on a glass plate with a scalpel. These films were dried first at room temperature and then in a circulating air drying cabinet for 1 hour at 80 ° C.

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The films were clear and elastic and resistant to isopropanol.

Ion content [meq./100 g] = 20.3

Example 4 (According to the invention)

544.1 g

176.0g

29.2 g

84.9 g

1619.0 g Acclaim® 2200N polyol Acclaim® 6300 polyol

-isocyanate-5- (¡soc¡anatome¡l) -1,3,3-trimethylcyclohexane (IPDI) toluene diisocyanate (TDI 80) acetone

75.1 g

0.8 g AAA ethylenediamine salt

1787.0 g partially deionized water

A mixture of 544.1 g of Acclaim® 2200 N polyol and 176.0 g of Acclaim® 6300 polyol was dehydrated at 110 to 120 ° C and 30 to 50 mbar for 1 hour. The mixture was then cooled to 90 ° C and 29.2 g of IPDI and 84.9 g of TDI 80 were added. After stirring at 95 to 105 ° C for about 7 hours, a prepolymer with isocyanate end groups was obtained with an isocyanate (NCO) content of 2.90% (theoretical NCO = 3.06%). The prepolymer was cooled to about 60 ° C and 1619 g of acetone was added with stirring. An amino chain extender solution prepared from 75.1 g of AAA salt and 0.8 g of ethylenediamine in 113 g of water at about 50 ° C was added to the clear, homogeneous prepolymer solution. The solution thus became cloudy and the viscosity increased slightly. After 15 minutes, 1.787 g of partially deionized water was added over 30 seconds, with rapid stirring. After about 200 ml of water, a low viscosity dispersion was formed. The acetone was then distilled off under vacuum induced by water jet at 50 ° C.

A finely divided stable dispersion with a mean particle size of 108 nm was obtained. The dispersion had a solids content of 34.0% and a Ford cup viscosity value (4mm nozzle) of 30 seconds at 25 ° C.

Films of the dispersion were prepared on a glass plate with a scalpel. and dried first at room temperature and then in a circulating air drying cabinet for 1 hour at 80 ° C.

The resulting films were clear and elastic and were shown to be resistant to isopropanol.

Ion content [meq./100 g] = 20.5

Example 5

Comparative example corresponding to Example 3 of European patent 741,152

400.0 g

20.3 g

122.5 g

12.3 g

13.2 g

70.0 g

780.0 g Acclaim® 4200N polyol dimethylolpropionic acid

-¡Socyanate-5- (isoanatomethyl) -1,3,3-trimethylcyclohexane triethylamine ethylenediamine fully deionized water fully deionized water

ES 2 335 892 T3

400.0 g of Acclaim® 4200 N polyol were dehydrated at 110 to 120 ° C and 30 to 50 mbar for 1 hour. Then 20.3 g of dimethylolpropionic acid were added and the mixture was stirred at 100 ° C for 30 minutes. Then it was cooled to 90 ° C and 122.5 g of 1-isocyanate-5- (isocyanatomethyl) -1,3,3-trimethylcyclohexane were added. The reaction continued at 100 ° C until a constant isocyanate content was obtained (theoretical value = 4.21% isocyanate). After cooling to 65 ° C, 12.3 g of triethylamine were added and the mixture was stirred for an additional 15 minutes. The prepolymer was poured into 780 g of fully deionized water kept at a constant temperature of 50 ° C, with vigorous stirring. After complete dispersion, the chain length was increased by adding 13.3 g of ethylenediamine in 70 g of fully deionized water. Stirring continued at 50 ° C until the dispersion was isocyanate free. A moderately finely divided stable dispersion was obtained.

TABLE 3

Mechanical properties and resistance to isopropanol

<td>Example</td><td>100% module [MPa]</td><td>Resistance to traction [MPa]</td><td>Elongation to break [%]</td><td>Isopropanol resistance</td><td>to the</td>

<td>1 (Comparison)</td><td> 1,1</td><td> 5,9</td><td> 850</td><td>do not</td><td></td>

<td> 2</td><td> 1,4</td><td> 16,4</td><td> 1310</td><td>resistant</td><td></td>

<td> 3</td><td> 1,7</td><td> 13,1</td><td> 1100</td><td>resistant</td><td></td>

<td> 4</td><td> 1,4</td><td> 11,6</td><td> 1620</td><td>resistant</td><td></td>

<td>5 (Comparison)</td><td> 5,9</td><td> 33,4</td><td> 900</td><td>do not</td><td></td>

Example 6 (Not according to the invention)

The following materials were charged into a reactor equipped with a heating mantle, a stirrer, a nitrogen inlet, a reflux condenser, and a charging hopper: 376.98 grams of a polyesterdiol (OH number 66, prepared from of adipic acid, hexanediol, and neopentylglycol) and 10.07 grams of a polyetherriol (a trimethylol propane / propylene oxide polyether with an OH number of 380 and a number average molecular weight of 440). The stirrer was then turned on and the mixture was heated to 58 ° C. At that temperature, 73.81 grams of hexamethylene diisocyanate were added. The reaction mixture was allowed to exotherm to 75 ° C and then held at 80 ° C until the isocyanate content reached 3.17% by weight (theoretical = 3.36%). The mixture was diluted with 691.28 g of acetone and cooled to 42.5 ° C. Over the next five minutes, a solution of 3.59 g of ethylenediamine and 20.81 grams of the sodium salt of N-2-aminoethane-2-aminoethanesulfonic acid in 107 grams of distilled water was added. Five minutes later, 600 g of distilled water was added with vigorous stirring (650 RPM) and the acetone was subsequently distilled off under reduced pressure. A fine dispersion was obtained with a particle size of approximately 231 nm and a solids content of 44% by weight.

Example 7 (Not according to the invention)

The following materials were charged into a reactor equipped with a heating mantle, a stirrer, a nitrogen inlet, a reflux condenser, and a charging hopper: 252.96 grams of a polyesterdiol (OH number 66, prepared from of adipic acid, hexanediol and neopentyl glycol) and 44.56 grams of polyetherriol based on propylene oxide (Acclaim 3300 - OH number of 57 and a number average molecular weight of 3000). The stirrer was then turned on and the mixture heated to 75 ° C. At that temperature, 49.53 grams of hexamethylene diisocyanate were added. The reaction mixture was allowed to exotherm to 80 ° C and then held at 72 ° C until the isocyanate content reached 2.68% by weight (theoretical = 2.99%). The mixture was diluted with 520.57 g of acetone and cooled to 44.5 ° C. During the following

ES 2 335 892 T3 five minutes, a solution of 2.29 g of ethylenediamine and 15.14 grams of the sodium salt of N-2-aminoethane-2-aminoethanesulfonic acid in 100 grams of distilled water was added. Ten minutes later, 557 g of distilled water was added and the acetone was then distilled off under reduced pressure. A fine dispersion was obtained with a particle size of the dispersed phase of about 185 nm and a solids content of 36% by weight.

Example 8 (Comparative example - non-superior functional material)

The following materials were charged into a reactor equipped with a heating mantle, a stirrer, a nitrogen inlet, a reflux condenser, and a charging hopper: 1133.0 grams of a polyesterdiol (OH number 66, prepared from of adipic acid, hexanediol and neopentyl glycol). The stirrer was then turned on and the mixture heated to 70 ° C. At that temperature, 201 grams of hexamethylene diisocyanate were added. The reaction mixture was allowed to exotherm to 85 ° C and then held at 85 ° C until the isocyanate content reached 2.84% by weight (theoretical = 3.32%). The mixture was diluted with 2405 g of acetone and cooled to 47 ° C. Over the next 30 seconds, a solution of 11.5 g of ethylenediamine and 53.3 grams of the sodium salt of N-2-aminoethane-2-aminoethanesulfonic acid in 300 grams of distilled water was added. Fifteen minutes later, 1800 g of distilled water were added and the acetone was then distilled off under reduced pressure. A fine particle dispersion was obtained with a particle size of the dispersed phase of about 87 nm and a solids content of 40% by weight.

Example 9 (Comparative Example - Triamine Branching)

The following materials were charged into a reactor equipped with a heating mantle, stirrer, nitrogen inlet, reflux condenser, and charging hopper: 380.0 grams of a polyesterdiol (OH number 66, prepared from of adipic acid, hexanediol and neopentyl glycol). The stirrer was then turned on and the mixture was heated to 70 ° C. At that temperature 67.2 grams of hexamethylene diisocyanate were added. The reaction mixture was allowed to exotherm to 70 to 75 ° C and then held at 75 ° C until the isocyanate content reached 2.98% by weight (theoretical = 3.32 %). The mixture was diluted with 795 g of acetone and cooled to 41.5 ° C. Over the next 30 seconds a solution of 3.49 g of ethylenediamine, 0.38 grams of diethylenetriamine and 8.05 grams of the sodium salt of N-2-aminoethane-aminoethanesulfonic acid in 100 grams of distilled water was added. 15 minutes later, 610 g of distilled water was added and the acetone was then distilled off under reduced pressure. A fine particle dispersion with a solids content of 41% was obtained.

Preparation of films from the dispersions of Examples 6 to 9

A coagulating solution consisted of a mixture of calcium carbonate and calcium nitrate. The coagulating solution was heated to 60 ° C and continuously stirred. A porcelain tube was preheated to 65.6 ° C. The tube was immersed in the coagulating solution and slowly removed. The tube was rotated to evenly distribute the coagulant. The tube was allowed to air dry for 60 seconds. The tube was then dipped into the polyurethane dispersion and slowly removed. The tube was rotated to evenly distribute the dispersion. The coating was allowed to air dry for 60 seconds. The coated tube was immersed in a container with water at 48.9 ° C for 2 minutes. The tube was placed in an oven at 148.9 ° C for 8 minutes. The cured film was dusted with cornstarch and removed from the tube by rolling the film. A flat film was obtained by cutting the polyurethane tube on one side. Each film was tested for isopropanol resistance using a Sterillium solution (a commercially available disinfectant / isopropanol solution).

A dumbbell-shaped sample was cut from the polyurethane film prepared as above. The ends of the "weight" were stretched so that the center portion of the film was elongated 100% (ie, a one-inch portion was elongated up to two inches). A drop of Sterillium® solution was deposited in the middle of the stretched section of the film. The amount of swelling or breakage of the film was recorded.

The films of the dispersions of Examples 6 and 7 did not swell, while the films of the dispersions of Examples 8 and 9 broke.