Curable polyurethane polymer

The present invention relates to a curable polyurethane polymer which comprises at least one hydroxyl-containing prepolymer having at least one thermally or photochemically free-radically polymerizable α, β-ethylenically unsaturated double bond in copolymerized form. The invention further relates to an aqueous polymer dispersion containing such a curable polymer in dispersed form and the use of the polymer or the polymer dispersion for coating substrates.

Aqueous polyurethane dispersions containing components having ethylenically unsaturated groups have found wide application. They are mainly used to produce coatings on non-flexible substrates, such. B. Wood, and flexible substrates, such. B. Leather. Due to their ability to crosslink, you get from these dispersions generally films with good performance properties, such. B. Chemical resistance and increased mechanical stability, compared with non-crosslinkable polyurethane dispersions. For the production of coatings on substrates which are not or only slightly thermally stable, polyurethane dispersions are generally used which are radiation-curable. An important feature of these curable by UV irradiation or by electron beam dispersions is that even after evaporation of the water contained films resulting in a possible tack-free and possibly already mechanically claimable surface. On the one hand, this also makes it possible to coat substrates which, due to their external shape, have beam shadow areas and are therefore not completely accessible to radiation curing for technical reasons. On the other hand, the substrates can be processed mechanically before curing. This is particularly important in the production of coatings on wood, since the surfaces are generally ground before curing, z. B. to remove the established wood fibers and to obtain a smooth surface in a second painting step. Another advantage lies in the freedom from tackiness of these coatings, so that the surfaces, for. B. when stacking, do not stick together.

DE-A-34 37 918 describes aqueous Oligourethandispersionen with incorporated, unsaturated groups and their use for the production of high-gloss paints on leather. EP-A-0 554 784 describes aqueous dispersions of a radiation-curable polyurethane which contains, as structural components, isocyanurate- or biuret-group-containing polyisocyanates and polyols. After evaporation of the water obtained from the aforementioned polyurethane dispersions coatings that are not mechanically durable before radiation curing or give sticky surfaces.

EP-A-0 209 684 describes aqueous emulsions based on urethane urea acrylates.

None of the abovementioned publications describes polymer dispersions based on polyurethanes which comprise hydroxyl-containing prepolymers in copolymerized form with α, β-ethylenically unsaturated double bonds.

US Pat. No. 4,357,221 describes a process for coating electrically conductive parts using an anionic polyurethane addition product which has .alpha.,. Beta.-ethylenically unsaturated, radiation-curable double bonds. To prepare this product, a solution of a polyurethane based on an acrylic ester diol, a low or high molecular weight chain extender and a polyisocyanate is reacted with a mercaptocarboxylic acid salt. The introduction of the carboxylate group in the polyurethane is carried out not by addition of the mercapto group to an isocyanate group, but to one of the double bonds present in the polyurethane to form a Mercaptoetherbrücke.

DE-A-40 31 732 describes radiation-curable, aqueous binder dispersions which<ul id="ul0001" list-style="none"><li>a) from 5 to 95% by weight of a self-dispersible polyurethane,</li><li>b) from 5 to 95% by weight of a prepolymer or prepolymer mixture dispersible by means of c),</li><li>c) 0 to 30 wt .-% of a protective colloid</li></ul> respectively.

Component a) is not an acrylate-containing prepolymer. The prepolymers b) may be polyesters, polyethers, polyepoxides or polyurethanes, which are added separately to the aqueous dispersions, which are therefore not bound to the polyurethane component a). The coatings obtained with the dispersions based on a mixture of a) and b) are in need of improvement in terms of their performance properties. Thus, the pendulum hardness of the radiation-cured films of the embodiments is a maximum of 115 s.

EP-A-0 392 352 describes aqueous dispersions of radiation-curable polyurethanes<ul id="ul0002" list-style="none"><li>a) 1. Gram equivalent NCO of a polyisocyanate,</li><li>b) 0.1 to 0.8 gram equivalents OH of a polyol having a molecular weight between 400 and 6000 g / mol,</li><li>c) 0 to 0.8 gram equivalents OH of a polyol having a molecular weight between 62 and 399 g / mol,</li><li>d) 0 to 0.4 gram equivalents NH of a polyamine having at least two isocyanate-reactive amino groups,</li><li>e) 0 to 0.4 gram equivalent of an amino alcohol OH with at least one isocyanate-reactive amino group,</li><li>f) from 0.05 to 0.5 gram equivalent of OH or NH of a compound having ionic groups or groups convertible into ionic groups with at least one isocyanate-reactive hydroxyl or amino group,</li><li>g) 0 to 0.2 gram equivalent of a monofunctional polyetherol OH as well as</li><li>h) a compound having at least one ethylenically unsaturated group and at least one hydroxyl group,</li></ul> with the provisos that (i) the sum of the OH and NH gram equivalents is between 0.9 and 1.2, (ii) the components under a) to h) may be in the form of individual components or mixtures, and (iii ) the ethylenically unsaturated component h) is used in amounts of 0.02 to 0.08 gram equivalent of OH. The content of polymerizable, ethylenically unsaturated groups per 1 000 g of polyurethane is thus very low and amounts to a maximum of 0.166 mol / kg.

DE-A-195 25 489 describes polyester acrylate urethane dispersions based on hydroxyl-containing polyester acrylate prepolymers. The preparation of these dispersions is carried out by polyaddition of<ul id="ul0003" list-style="none"><li>a) 40 to 90 wt .-% of one or more hydroxyl-containing Polyesteracrylatpräpolymeren having an OH content of 40 to 120 mg KOH / g and</li><li>b) 0,1. to 20% by weight of one or more mono- and / or difunctional compounds which are reactive toward isocyanate groups and contain cationic, anionic and / or etheric dispersing groups</li><li>c) 10 to 50 wt .-% of one or more polyisocyanates and subsequent reaction with</li><li>d) 0.1 to 10 wt .-% of one or more di- and / or polyamines.</li></ul>

The coatings obtained with these dispersions are in need of improvement in terms of their performance properties. Thus, the not yet radiation-cured films have too low pendulum hardness, d. H. Under mechanical stress, the coated substrates adhere to each other and other uncoated surfaces, and subsequent substrate separation can cause surface damage. This is particularly disadvantageous if the dispersions, as described above, are used for coating surfaces which have poorly accessible shadow areas during radiation curing. The cured films are also in need of improvement in terms of their mechanical properties, in particular a good surface hardness with simultaneous flexibility of the film.

In none of the aforementioned documents are curable polyurethane polymers described in which the molar ratio of incorporated isocyanate group-containing components to components having isocyanate-reactive groups is selected such that the latter are reacted only to a maximum of 90%.

The object of the present invention is to provide a curable polyurethane polymer which is suitable for the preparation of aqueous polymer dispersions having good performance properties.

Surprisingly, it has now been found that the object is achieved by a curable polyurethane polymer in which the ratio of isocyanate group equivalents of the incorporated isocyanate group-containing components to equivalents of isocyanate-reactive groups of the components with active hydrogen atoms in a range of about 0.4: 1 to 0.9: 1 lies.

The present invention therefore provides a curable polyurethane polymer which<ul id="ul0004" list-style="none"><li>A) from 10 to 60% by weight, based on the total weight of components A) to F), of at least one hydroxyl-containing prepolymer having at least one thermally or photochemically polymerizable α, β-ethylenically unsaturated double bond,</li><li>B) 0.1 to 30 wt .-%, based on the total weight of components A) to F), of at least one compound having at least one isocyanate-reactive hydroxyl and / or primary or secondary amino group and additionally at least one polar functional group per Molecule,</li><li>C) 0.1 to 30% by weight, based on the total weight of components A) to F), of at least one compound selected from diamines, polyamines and mixtures thereof,</li><li>D) 0 to 10 wt .-%, based on the total weight of components A) to F), at least one other of A), B), C) and E) different compound having at least two isocyanate-reactive groups, wherein it is are hydroxyl groups and mixtures of hydroxyl groups with primary and / or secondary amino groups,</li><li>E) 0 to 20% by weight, based on the total weight of components A) to F), of at least one compound having an isocyanate-reactive group,</li><li>F) from 10 to 65% by weight, based on the total weight of components A) to F), of at least one compound having at least two isocyanate groups,</li></ul> in copolymerized form, and the salts thereof, which is characterized in that the ratio of isocyanate group equivalents of component F) to equivalents of isocyanate-reactive groups of components A) to E) in a range of 0.4: 1 to 0, 9: 1 lies.

The ratio of isocyanate group equivalents of component F) to equivalents of isocyanate-reactive groups of components A) to E) is preferably in a range from about 0.45: 1 to 0.8: 1.

The sum of the hydroxyl numbers of components A) and D) is preferably in a range of about 40 to 300 mg KOH / g. The hydroxyl numbers of the components A) and D) of the polymers of the invention z. B. in a range of about 40 to 120 mg KOH / g. The sum of the hydroxyl numbers of components A) and D) is preferably in the range from 121 to 300 mg KOH / g, more preferably from 125 to 220 mg KOH / g, in particular from 130 to 200 mg KOH / g.

If desired, the use of a component D) in the polymers according to the invention can be dispensed with. Preferably, the hydroxyl number of the prepolymer A) is then in a range of about 121 to 300 mg KOH / g, preferably about 123 to 220 mg KOH / g, in particular about 125 to 200 mg KOH / g. According to a possible embodiment, however, the polymers according to the invention may also contain incorporated a prepolymer A) having a hydroxyl number of at least 121 mg KOH / g and additionally a component D).

The content of polymerizable, α, β-ethylenically unsaturated double bonds is generally in a range of about 1.0 to 4.0 mol per 1000 g of polymer, preferably about 1.1 to 3.8 mol, in particular 1.2 to 3 , 5 mol per 1 000 g of polymer.

The content of polar functional groups of the polymers according to the invention is generally in a range of about 0.8 to 3.5 wt .-%, preferably from 0.9 to 3.3 wt .-%. Polymers having a content of polar functional groups in the range of about 1.3 to 3.5 wt .-% are generally self-dispersible and can be formulated, if desired, even without the addition of dispersants to the polymer dispersions of the invention.

The K value of the prepolymer before dispersion and chain extension determined by E. Fikentscher, Cellulose Chemistry 13 (1932), p. 58-64, on a 1% solution in dimethylformamide, is in a range of about 20 to 70, preferably 30 to 60, in particular 45 to 55.

Hydroxyl-containing prepolymers A) having at least one thermally or photochemically free-radically polymerizable α, β-ethylenically unsaturated double bond are preferably selected from polyester acrylates, polyether acrylates, polyurethane acrylates, epoxy acrylates, and mixtures thereof.

Suitable polyester acrylates are z. B. the polycondensation of α, β-ethylenically unsaturated mono- and / or dicarboxylic acids and their anhydrides with polyester polyols. As α, β-ethylenically unsaturated mono- and / or dicarboxylic acids and their anhydrides z. B. Acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, crotonic acid, itaconic acid, etc are used. Preference is given to using acrylic acid and methacrylic acid. Suitable polyesterols are linear and branched polymers with terminal OH groups, eg. B. those with at least two OH end groups. The polyesterols can be prepared in a simple manner by esterification of aliphatic, cycloaliphatic and aromatic di-, tri- and / or polycarboxylic acids with di-, tri- and / or polyols. Suitable carboxylic acids are, for. B. Dicarboxylic acids having 2 to 20 carbon atoms, preferably 4 to 15 carbon atoms, for example, malonic acid, succinic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, sebacic acid, dodecanedioic acid, phthalic acid, terephthalic acid, isophthalic acid, cyclohexane dicarboxylic acid, etc. Also suitable are sulfosuccinic acid and sulfoisophthalic acid. The dicarboxylic acids can be used individually or as mixtures. Suitable diols are z. B. Glycols, preferably glycols having 2 to 25 carbon atoms. Examples of suitable glycols are, for. B. 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, diethylene glycol, 2,2,4-trimethylpentanediol-1,5, 2,2-Dimethylpropanediol-1,3, 1,4-cyclohexanediol, 1,4-dimethylolcyclohexane, 1,6-dimethylolcyclohexane and ethoxylated / propoxylated products of 2,2-bis- (4-hydroxyphenyl) -propane (bisphenol-A ), Etc. Suitable triols and polyols have z. Third 3 to 25, preferably 3 to 18 carbon atoms. These include z. B. Glycerol, trimethylolpropane, erythritol, pentaerythritol, sorbitol and their alkoxilates etc. Suitable polyesterols can also be prepared by polymerization of lactones, eg. B. Lactones having 3 to 20 carbon atoms, produce. As lactones for the preparation of polyesterols are z. B. α, α-dimethyl-β-propiolactone, γ-butyrolactone, ε-caprolactone, etc.

Further suitable polyester acrylates are condensation products based on hydroxyl-containing esters of acrylic acid and / or methacrylic acid with at least dihydric alcohols. These include z. B. 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate, 3-hydroxy-2-ethylhexyl acrylate, 3-hydroxy-2-ethylhexyl methacrylate, di (meth) acrylic ester of 1,1,1-trimethylolpropane or glycerol. These hydroxyl-containing esters can be polycondensed with polyester carboxyl-terminated or polyester-forming dicarboxylic acids and glycols to form polyester acrylates.

Suitable polyether acrylates A) are, for. B. the polycondensation of the aforementioned α, β-ethylenically unsaturated mono- and / or dicarboxylic acids and their anhydrides with polyetherols. In this case, linear or branched terminal hydroxyl-containing substances which contain ether bonds and a molecular weight in the range of z. B. about 300 to 10,000, preferably from 400 to 5000 possess. Suitable polyetherols can be readily prepared by the polymerization of cyclic ethers such as tetrahydrofuran or by reacting one or more alkylene oxides containing from 2 to 4 carbon atoms in the alkyl radical with a starter molecule containing two active hydrogens in the alkylene radical. Examples of alkylene oxides include ethylene oxide, 1,2-propylene oxide, epichlorohydrin, 1,2- and 2,3-butylene oxide. The alkylene oxides can be used individually, alternately in succession or as a mixture. As a starter molecule z. B. Water, the aforementioned glycols, polyesterols, triols and polyols, amines such as ethylenediamine, hexamethylenediamine and 4,4'-diaminodiphenylmethane and amino alcohols such as ethanolamine, into consideration. Like the polyesterols, the polyetherols can also be used alone or in mixtures.

Suitable polyurethane acrylates A) are z. B. the polyaddition products of the polyisocyanates described below as component F) with the above-described hydroxyl-containing esters of acrylic and / or methacrylic acid with at least dihydric alcohols. As polyisocyanates are preferably diisocyanates, such as. B. 2,4- and 2,6-toluene diisocyanate (TDI) and isomer mixtures thereof, tetramethylxylylene diisocyanate (TMXDI), tetramethylene diisocyanate, hexamethylene diisocyanate (HDI) and its trimers, isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate, 1,3-cyclohexane diisocyanate and its trimers, dicyclohexylmethane diisocyanate ( H₁₂MDI), xylene diisocyanate (XDI) and diphenylmethane diisocyanate (MDI). Preferred hydroxyl-containing esters of acrylic acid and / or methacrylic acid are the abovementioned hydroxyalkyl (meth) acrylates, preferably hydroxymethyl acrylate, hydroxypropyl acrylate and hydroxyethyl methacrylate.

Suitable epoxy acrylates A) are, for. B. the reaction products of compounds having at least one epoxide group, with compounds having at least one α, β-ethylenically unsaturated double bond and at least one epoxy group-reactive group per molecule. The latter are preferably selected from α, β-ethylenically unsaturated mono- and dicarboxylic acids and their anhydrides, in particular acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, crotonic acid and itaconic acid. Particular preference is given to using acrylic acid and / or methacrylic acid. The epoxide group-containing compound is preferably selected from glycidyl ethers, glycidyl esters, epoxidized olefins, epoxidized cyclic ureas, epoxidized triazines and mixtures thereof. The preparation of suitable glycidyl ethers z. B. by reacting at least one aliphatic, cycloaliphatic or aromatic, monohydric, dihydric or polyhydric alcohol with at least one epoxide compound which in α-position to the epoxide group is a suitable leaving group, such as, for example, B. Halogen, has. Epichlorohydrin is preferably used as the epoxide compound for the production of glycidyl ether, as well as for the production of glycidyl esters and for the epoxidation of ureas and triazines. At least one of the aforementioned di-, tri- and / or polyols is preferably used as the alcohol component for the production of glycidyl, in particular 1,4-butanediol, 1,4-cyclohexanediol, 1,4-dimethylolcyclohexane, 1,6-dimethylolcyclohexane, bisphenol A, hydrogenated bisphenol A and mixtures thereof.

In the reaction of di- or polyhydric alcohols and epoxide compounds which have a leaving group in the α-position to the epoxide group, depending on the molar ratio of epoxide compound to alcohol component glycidyl ether or, with increasing amount of alcohol, higher molecular weight, hydroxyl-containing di- or polyepoxides. In general, both glycidyl ethers and relatively high molecular weight products are suitable for the preparation of epoxyacrylates A) which can be used according to the invention. Preferred glycidyl esters for the preparation of epoxy acrylates A) are, for. B. the reaction products of aliphatic, cycloaliphatic or aromatic mono-, di- or polybasic carboxylic acids with at least one epoxide compound which have a leaving group in the α-position to the epoxide group. Preferably, as the carboxylic acid component for Glycidesterherstellung dicarboxylic acids such. B. used dimerized fatty acids. A preferred glycidyl ester for the preparation of epoxy acrylates A) which can be used according to the invention is bis-epoxycyclohexylmethylcarboxylate. Preferred epoxide-containing compounds for the preparation of epoxy acrylates A) which can be used according to the invention are furthermore aromatic glycidylamines, in particular the triglycidyl adduct of p-aminophenol and the tetraglycidylamine of methylenedianiline, heterocyclic glycidylimides and glycidylamides, in particular triglycidyl isocyanurate, and hydantoin-based epoxy resins, etc. Suitable epoxy group-containing compounds for preparing the epoxy acrylates A) are known to the person skilled in the art and are commercially available. These include z. B. the Araldit® grades of the company. Ciba.

Suitable epoxy acrylates A) are furthermore epoxy acrylates based on epoxynovolacene, epoxidized oils, such as soya or linseed oil, etc.

Preferred epoxy acrylates A) are selected from the reaction products of 1,4-butanediol diglycidyl ether, 1,4-cyclohexanediol diglycidyl ether, 1,4- and 1,6-dimethylolcyclohexanediglycidyl ether, bisepoxycyclohexylmethylcarboxylate, triglycidyl isocyanurate and bisphenol A diglycidyl ether with acrylic acid and / or methacrylic acid and mixtures thereof reaction products. Particularly preferred epoxy acrylates A) are the reaction products of one mole of a bisphenol A diglycidyl ether (eg. B. Epikote® 828 of the Fa. Shell) with two moles of acrylic acid or methacrylic acid. The hydroxyl number of Epikote® 828-diacrylate is about 215 mg KOH / g. Particular preference is also given to using mixtures of epoxy acrylates A) which contain at least one epoxy acrylate based on a bisphenol A diglycidyl ether.

In a preferred embodiment, the prepolymer A) is a reaction product or a mixture of<ul id="ul0005" list-style="none"><li>a) at least one polyester acrylate and / or polyether acrylate and / or polyurethane acrylate and</li><li>b) at least one epoxy acrylate.</li></ul>

Polyester acrylates, polyether acrylates, polyurethane acrylates and epoxy acrylates and their preparation are described, for. In NS Allen, MA Johnson, P. Old-ring (ed.) And MS Salim, Chemistry &amp; Technology of UV &amp; EB Curing Formulations for Coatings, Inks &amp; Paints, Vol. 2, SITA Technology, London 1991.

The polyurethane polymer according to the invention comprises component B) which has at least one isocyanate-reactive hydroxyl and / or amino group and additionally at least one polar functional group, generally in a proportion of about 0.1 to 30% by weight, preferably 1, 0 to 25 wt .-%, in particular 2.0 to 20 wt .-%, based on the total weight of components A) to F), copolymerized. Component B) is selected from substances which have at least one polar functional group selected from ionogenic and / or ionic groups and also polyether groups.

These groups generally favorably favor the dispersion of the polyurethanes in water. In the ionogenic or ionic groups are preferably carboxylic acid groups, phosphonic acid groups, phosphoric acid groups and / or sulfonic acid groups and / or nitrogen-containing groups (amines) or Carboxylate groups and / or sulfonate groups and / or quaternized or protonated groups. As component B) can therefore z. B. Hydroxycarboxylic acids, such as hydroxyacetic acid (glycolic acid), hydroxypropionic acid (lactic acid), malic acid (malic acid) and salts thereof, preferably dimethylolpropanoic acid and their alkali metal and ammonium salts are used.

Suitable compounds B) which have at least one sulfonic acid group or a sulfonate as a polar functional group are, for. B. the diester or polyester diols of dicarboxylic acids which additionally have at least one sulphonic acid group or metal sulphonate group, with the diols previously mentioned as starting materials of the prepolymers A). As dicarboxylic acids may be z. B. Sulfosuccinic acid, 4-sulfophthalic acid, 5-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5- (4-sulfophenoxy) terephthalic acid or the corresponding metal sulfonates. The alkali metal salts of the abovementioned sulfodicarboxylic acids, in particular the sodium and potassium salts, are preferably used. Particularly preferred are 5-sodiosulfoisophthalic acid, 5-potassium sulfoisophthalic acid, sodium sulfoterephthalic acid and potassium sulfoterephthalic acid. Further suitable compounds B) which have at least one sulfonic acid or sulfonate group are correspondingly substituted straight-chain or branched aliphatic, cycloaliphatic or aromatic diols. These include z. B. 2-sulfo-1,4-butanediol, 2,5-dimethyl-3-sulfo-2,5-hexanediol and their sodium and potassium salts.

Also useful are compounds B) of the formulas<chemistry id="chem0001" num="0001"><img file="EP1069144A2_D0001.tif" /></chemistry> wherein each R is a C₂-C₁₈Alkylene group and Me is Na or K.

Also useful as component B) are compounds of the formulas         H₂N (CH₂ )_n-NH- (CH₂ )_mCOO-M⁺        H₂N (CH₂ )_n-NH- (CH₂ )_m-SO₃M⁺wherein m and n are independently an integer from 1 to 8, especially 1 to 6, and M is hydrogen, Li, Na, K or ammonium. The compounds m and n are preferably 2.

If compounds with nitrogen-containing groups are used as component B), cationic polyurethanes are obtained. Useful components B) are z. B. Compounds of the general formulas<chemistry id="chem0002" num="0002"><img file="EP1069144A2_D0002.tif" /></chemistry> wherein<ul id="ul0006" list-style="none" compact="compact"><li>R¹ and R², which may be the same or different, for C₂-C_8thAlkylene,</li><li>R³, R⁶ and R⁷, which may be the same or different, for C₁-C₆Alkyl, phenyl or phenyl-C₁-C₄alkyl,</li><li>R⁴ and R⁵, which may be the same or different, for H or C.₁-C₆Alkyl,</li><li>X- for an anion, preferably for chloride, bromide, iodide, C₁-C₆Alkyl sulfate or SO₄²-_{/ 2} stands.</li></ul>

According to another suitable embodiment, component (B) is an amine of the formula:         R¹⁰HN-Y-SO₃H wherein<dl id="dl0001"><dt>Y</dt><dd>for o-, m- or p-phenylene or straight-chain or branched C₂-C₆-Alkylene, which is optionally substituted by 1, 2 or 3 hydroxy groups, and</dd><dt>R¹⁰</dt><dd>for a hydrogen atom, a C₁-C₁₂Alkyl group (preferably C₁-C₁₀- and in particular C₁-C₆Alkyl group) or a C₅-C₆-Cycloalkyl group, wherein the alkyl group or the cycloalkyl group may optionally be substituted by 1, 2 or 3 hydroxy groups, carboxyl groups or sulfonic acid groups.</dd></dl>

The amine of the above formula is preferably taurine, N- (1,1-dimethyl-2-hydroxyethyl) -3-amino-2-hydroxypropanesulfonic acid or 2-aminoethylaminoethanesulfonic acid.

According to another suitable embodiment, the amine is a conventional α-, β- or γ-amino acid, for example glycine, alanine, valine, leucine, isoleucine, phenylalanine, tyrosine, proline, hydroxyproline, serine, threonine, methionine, cysteine , Tryptophan, β-alanine, aspartic acid or glutamic acid.

The polyurethanes containing acid groups can be converted by neutralization (partially or completely) into a water-dispersible form. As the base for the neutralization, alkali metal bases such as caustic soda, potassium hydroxide, sodium carbonate, sodium hydrogencarbonate, potassium carbonate or potassium hydrogencarbonate and alkaline earth metal bases such as calcium hydroxide, calcium oxide, magnesium hydroxide or magnesium carbonate and ammonia and amines such as trimethylamine, triethylamine, triisopropylamine, etc. can be used. The neutralization of the polyurethanes containing acid groups can also be carried out with the aid of mixtures of several bases, for. B. Mixtures of an alkali metal hydroxide such as sodium hydroxide and an amine such. B. Triethanolamine, triisopropanolamine, etc. The neutralization may, if desired, partially z. B. 10 up to 99%, such as B. to 20 to 80% or completely, d. H. 100%.

Charged cationic groups can be prepared from the present tertiary amine nitrogen atoms either by protonation, e.g. As with carboxylic acids such as acetic acid, propionic acid, butyric acid and lactic acid, or by quaternization, for. B. with alkylating agents such as C.₁- to C₄Produce alkyl halides or sulfates. Examples of such alkylating agents are ethyl chloride, ethyl bromide, methyl chloride, methyl bromide, dimethyl sulfate and diethyl sulfate.

The compounds suitable as component B), which have only one isocyanate-reactive group, act as stopping agents which interrupt the polyaddition. If desired, they can be added at the end of the polyaddition reaction in the preparation of the polymers according to the invention, in order to react, if desired, at least some of the remaining free isocyanate groups.

Preference is given to using as component B) compounds which have at least two isocyanate-reactive groups, such as. B. amino and / or hydroxyl groups and at least one further polar functional group.

As compounds B) it is also possible to use the polyetherols previously described as component of the prepolymers A) based on cyclic ethers and alkylene oxides. Furthermore, α, ω-Diaminopolyether are suitable, the z. B. are obtainable by reaction of the polyetherols with ammonia. Suitable compounds B) are also z. B. alkoxylated trimethylolpropane alkoxylated on a hydroxyl group, the alkoxylate moiety having a terminal carboxylate or sulfonate group. The Alkoxylatrest can z. B. Ethylene oxide, propylene oxide and mixtures thereof incorporated. The molecular weight of these compounds is in a range of about 500 to 2,000. They are z. B. as Tegomer® grades of the company. Goldschmidt available.

The polyurethanes contain as component C) at least one compound selected from diamines, polyamines and mixtures thereof in a proportion of about 0.1 to 30 wt .-%, preferably 0.5 to 25 wt .-%, in particular 1 to 20 wt .-%, based on the total weight of components A) to F), copolymerized. Component C) contains no polar functional groups.

Suitable amines C) are straight-chain and branched, aliphatic and cycloaliphatic amines having generally from about 2 to 30, preferably about 2 to 20 carbon atoms. These include z. B. Ethylene diamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, diethylenetriamine, triethylenetetraamine, 4-azaheptamethylenediamine, N, N'-bis (3-aminopropyl) -butane-1,4-diamine, and mixtures thereof. Suitable polyamines C) generally have a number average molecular weight of about 400 to 10,000, preferably about 500 to 8,000. These include z. B. Polyamides having terminal, primary or secondary amino groups, polyalkyleneimines, preferably polyethyleneimines and by hydrolysis of poly-N-vinylamides, such as. B. Poly-N-vinylacetamide, vinylamines obtained and the abovementioned α, ω-diamines based on aminated polyalkylene oxides. Copolymers containing α, β-ethylenically unsaturated monomers with appropriate functional groups, eg. B. Aminomethyl acrylate, aminoethyl acrylate, (N-methyl) aminoethyl acrylate, (N-methyl) aminoethyl methacrylate, etc., in copolymerized form, are also suitable for introducing photochemically or radically curable double bonds into the polyurethanes.

The polyurethanes may optionally further comprise, as component D), at least one further compound having at least two isocyanate-reactive groups in an amount of from 0.01 to 10% by weight, preferably from about 0.1 to 5% by weight, to further optimize the polymer properties. based on the total weight of components A) to F), in copolymerized form.

As component D) z. B. Polyols are used whose molecular weight is generally in a range of about 62 to 399 g / mol. These include z. B. Diols having 2 to 18 carbon atoms, preferably 2 to 10 C atoms, such as 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,5-pentanediol, 1,10- Decanediol, 2-methyl-1,3-propanediol, 2-methyl-2-butyl-1,3-propanediol, 2,2-dimethyl-1, 3-propanediol, 2,2-dimethyl-1,4-butanediol, 2-ethyl-2-butyl-1,3-propanediol, hydroxypivalic acid neopentyl glycol ester, diethylene glycol and triethylene glycol. Suitable triols and higher polyols are compounds having 3 to 25, preferably 3 to 18, particularly preferably 3 to 6, carbon atoms. Examples of useful triols are glycerol or trimethylolpropane. As higher polyols, for example, erythritol, pentaerythritol and sorbitol can be used. Also suitable are low molecular weight reaction products of the polyols, for. B. of trimethylolpropane with alkylene oxides, such as ethylene oxide and / or propylene oxide. These low molecular weight polyols may be used singly or as mixtures.

Suitable components D) are also amino alcohols having 2 to 16, preferably 3 to 6 carbon atoms, such as. Monoethanolamine, methylisopropanolamine, ethylisopropanolamine, methylethanolamine, 3-antinopropanol, 1-ethylaminobutan-2-ol, methylenediethanolamine, 4-methyl-4-aminopentan-2-ol and N- (2-hydroxyethyl) -aniline and mixtures thereof.

As component D) it is also possible to use relatively high molecular weight polyols having a number average molecular weight in the range from about 400 to 6,000 g / mol, preferably from 500 to 4,000 g / mol. These include z. B. the polyesterols described above in the case of component A) based on aliphatic, cycloaliphatic and / or aromatic di-, tri- and / or polycarboxylic acids with di-, tri- and / or polyols and the lactone-based polyesterols. These also include the polyetherols also described above in the case of component A), which are obtainable by polymerization of cyclic ethers or by reacting alkylene oxides with a starter molecule. These also include customary, known to the expert polycarbonates with terminal hydroxyl groups, which are obtainable by reacting the diols described above or bisphenols, such as bisphenol A, with phosgene or carbonic acid diesters. Also suitable are α, ω-polyamidoles, α, ω-polymethyl (meth) acrylate diols and / or α, ω-polybutyl (meth) acrylate diols, such as. B. MD-1000 and BD-1000 of the Fa. Goldschmidt.

The aforementioned components D) can be used individually or as mixtures.

The polyurethanes may have, as component E), at least one further compound having only one isocyanate-reactive group. This group may be a hydroxyl or a primary or secondary amino group. The polyurethanes according to the invention may contain component E) in copolymerized form in an amount of from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight, based on the total amount of components A) to F).

As component E) z. B. monofunctional alcohols, such as. As methanol, ethanol, n-propanol, isopropanol, etc., are used. Suitable components E) are also amines having a primary or secondary amino group, such as. Methylamine, ethylamine, n-propylamine, isopropylamine, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, etc.

The component E) may also be monohydric polyether alcohols having a number average molecular weight in the range from about 500 to 10,000 g / mol, preferably from 1000 to 5000 g / mol. Monohydric polyether alcohols are obtainable by alkoxylation of monovalent initiator molecules, such as methanol, ethanol or n-butanol, using as the alkoxylating agent ethylene oxide or mixtures of ethylene oxide with other alkylene oxides, especially propylene oxide.

By virtue of this component E), polyethylene oxide segments present in the polyurethanes, if appropriate in terminally and / or laterally arranged polyether chains, can be incorporated, which influence the hydrophilic character in the polyurethane in addition to the ionic groups.

The compounds of the type mentioned with polyethylene oxide units present within terminally and / or laterally arranged polyether chains are used in amounts such that in the polyurethane dispersions 0 to 10% by weight, preferably 0 to 5% by weight, within end - And / or laterally arranged polyether chains built polyethylene oxide units may be present in the polyurethanes. The total amount of the hydrophilic structural units (ionic groups and ethylene oxide units of the latter type) is generally chosen so that the dispersibility of the polyurethanes is ensured in water.

The polyurethanes comprise as component F) at least one polyisocyanate in a proportion of about 10 to 65 wt. -%, preferably about 15 to 60 wt .-%, based on the total weight of components A) to F), copolymerized. Suitable polyisocyanates F) are selected from compounds having 2 to 5 isocyanate groups, isocyanate prepolymers having an average number of 2 to 5 isocyanate groups, and mixtures thereof. These include z. B. aliphatic, cycloaliphatic and aromatic di-, tri- and polyisocyanates. Suitable diisocyanates F) are z. B. Tetramethylene diisocyanate, hexamethylene diisocyanate, 2,3,3-trimethylhexamethylene diisocyanate, 1,4-cyclohexylene diisocyanate, isophorone diisocyanate, 1,4-phenylene diisocyanate, 2,4- and 2,6-toluene diisocyanate, and isomeric mixtures thereof (e.g. B. 80 % 2,4- and 20% 2,6-isomer), 1,5-naphthylene diisocyanate, 2,4- and 4,4'-diphenylmethane diisocyanate. A suitable triisocyanate is z. B. Triphenylmethane-4,4 ', 4' '- triisocyanate. Also suitable are isocyanate prepolymers and polyisocyanates obtainable by addition of the aforementioned isocyanates to polyfunctional compounds containing hydroxyl or amine groups. Also suitable are polyisocyanates formed by biuret or isocyanurate formation. Hexamethylene diisocyanate, trimerized hexamethylene diisocyanate, isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluylene diisocyanate, and mixtures thereof are preferably used.

Another object of the invention are polymer dispersions containing at least one of the previously described polymers in dispersed form. The polyurethane dispersions according to the invention are prepared by customary methods known to the person skilled in the art. These are z. B. in Ullmann's Encyclopedia of Industrial Chemistry, 5. Edition, vol. A21, VCH Weinheim, (1992), p. 678-680. This includes z. B. the spontaneous dispersion of polyurethane ionomers by the acetone process, prepolymer mixing process, melt emulsion process, etc. This also includes the ketimine and ketazine method and the dispersion of precursors, in which hydrophilic oligomers are dispersed.

For the preparation of the curable polyurethane polymers of the invention can, for. B. the components A), B), F) and optionally D) and / or E) are first reacted in the melt or in the presence of an inert, water-miscible solvent to an isocyanate-containing polyurethane prepolymer. Preferred solvents are, for. B. Acetone, tetrahydrofuran, methyl ethyl ketone and N-methylpyrrolidone. The reaction temperature is generally in a range of about 20 to 160 ° C, preferably about 50 to 100 ° C. You can z. B. Heat the batch under ambient pressure to reflux. To accelerate the addition reaction, conventional catalysts, such as. Third Dibutyltin dilaurate, stannous octoate, 1,4-diazabicyclo [2.2.2] octane or amines such as triethylamine. To avoid unwanted, premature polymerization of the α, β-ethylenically unsaturated groups, polymerization inhibitors may optionally be added during the preparation of the polyurethane. For z. B. Quinones, phenols or phenol derivatives such as p-benzoquinone, hydroquinone, p-methoxyphenol, phenothiazine, 2,2,6,6-tetramethylpiperidin-1-yloxy, 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-yloxy Etc. Suitable polymerization inhibitors are, for. B. in Encyclopedia of Polymer Science &amp; Technology, Vol. 7, 1967, p. 644-664, published by Wiley &amp; Sons, New York-LondonSydney.

After preparation of the polyurethane prepolymer containing isocyanate groups, if desired, the copolymerized ionogenic groups, as described above for component B), can be ionized by neutralization or quaternization. If at least one compound having only one isocyanate-reactive group is used as the sole or additional component B) for the preparation of the polymers according to the invention, they are generally added only towards the end or after the reaction of the other components. If the preparation of the polymers according to the invention is carried out using a component E) which likewise has only one isocyanate-reactive group and thus acts as a stopper, its addition generally takes place only towards the end or after the reaction of the other components, if appropriate also after addition component C).

Finally, the isocyanate-group-containing prepolymer with component C) is converted into the substantially isocyanate-free polyurethane according to the invention, wherein a molecular weight increase takes place. According to a preferred embodiment, component C) is used together with at least part of the dispersing water necessary for the preparation of the polymer dispersions according to the invention. In this case, the polyurethane prepolymers containing isocyanate groups can either be introduced into the dispersing water containing component C), or a mixture of component C) and dispersing water is added to the isocyanate-containing polyurethane prepolymers. The amount of component C) is chosen so that a substantially isocyanate group-free polyurethane is obtained. If desired, the solvent can be distilled off after addition of the dispersing water. The amount of dispersing water is such that the resulting aqueous polyurethane dispersions have a solids content of about 10 to 70 wt .-%, preferably about 20 to 60 wt. -%' respectively.

In the preparation of the polymers according to the invention, the quantitative ratio of components A) to F) is selected so that the ratio of isocyanate group equivalents of component F) to equivalents of isocyanate-reactive groups of components A) to E) in the range of 0.4: 1 to 0.9: 1.

In general, the polyurethane polymers according to the invention having a content of polar functional groups in the range of about 1.3 to 3.5 wt .-% are self-dispersible, so that can be dispensed with the use of a dispersing aid. If desired, however, customary dispersing agents known to the person skilled in the art can be used for their preparation. These include z. As the following emulsifiers and protective colloids.

According to a suitable embodiment, the polymer dispersions according to the invention additionally comprise at least one dispersing assistant. For the preparation of these polymer dispersions are then also polyurethane polymers containing a smaller proportion of compounds of component B) and thus incorporated in dispersing active groups. For the preparation of these polymer dispersions, preference is given to using a polymer which comprises component B) in an amount of about 0.1 to 15% by weight, preferably about 0.1 to 10% by weight, based on the total amount of components A). to F), incorporated.

For the preparation of the polymer dispersions which additionally comprise at least one dispersant, it is preferred to prepare polymers having a content of polar functional groups in a range from about 0.8 to 1.5% by weight, in particular from about 0.9 to 1.3% by weight. -%, used.

Advantageously, by using at least one dispersing aid, it is possible to prepare polymer dispersions according to the invention having a higher solids content and / or a lower viscosity than corresponding dispersions without dispersing aids.

Preferably, the solids content of the polymer dispersions according to the invention with dispersing aid is at least 38% by weight, preferably at least 40% by weight.

The polymer dispersions according to the invention generally have lower viscosities than dispersions based on polyurethanes, in the preparation of which the isocyanate-reactive groups have been reacted to 100%.

Preferably, the viscosity of the polymer dispersions according to the invention with dispersing aid, determined according to DIN 53019 with a Rheomat 30 (23 ° C, shear rate D = 250 s^-1) at most 1 000 mPas, preferably at most 700 mPas.

As dispersing agents it is possible to use generally customary emulsifiers and / or protective colloids. The amount used is generally in a range of about 0.05 to 20 wt .-%, preferably about 0.1 to 15 wt .-%, based on the amount of the curable polyurethane polymer.

Suitable emulsifiers are the emulsifiers known to those skilled in the art, usually used as emulsifying agents in aqueous emulsion polymerization, as described, for example, in US Pat. B. in Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, Macromolecular Materials, Georg-Thieme-Verlag, Stuttgart, 1961, S. 411 - 420 are described. Both anionic, cationic and nonionic emulsifiers are suitable. Preference is given to using emulsifiers whose relative molecular weights, in contrast to protective colloids, are usually below 3500 daltons.

Useful nonionic emulsifiers are araliphatic or aliphatic nonionic emulsifiers, for example ethoxylated mono-, di- and trialkylphenols (EO degree: 3 to 50, alkyl radical: C₄-C₁₀), Ethoxylates of long-chain alcohols (EO degree: 3 to 50, alkyl radical: C_8th-C₃₆) as well as polyethylene oxide / polypropylene oxide block copolymers. Preferred are ethoxylates of long-chain alkanols (alkyl radical C₁₀-C₂₂, average degree of ethoxylation 10 to 50), and more preferably those having a linear C₁₂-C₁₈Alkyl radical and a mean degree of ethoxylation of 10 to 50 and ethoxylated monoalkylphenols.

Suitable anionic emulsifiers are, for example, alkali metal and ammonium salts of alkyl sulfates (alkyl radical: C_8th-C₂₂), of sulfuric monoesters of ethoxylated alkanols (EO degree: 2 to 50, alkyl: C₁₂-C₁₈) and ethoxylated alkylphenols (EO grade: 3 to 50, alkyl: C₄-C₉), of alkylsulfonic acids (alkyl group: C₁₂-C₁₈) and of alkylarylsulfonic acids (alkyl group: C₉-C₁₈). Further suitable emulsifiers can be found in Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, Macromolecular substances, Georg-Thieme-Verlag, Stuttgart, 1961, pp 192- 208. As anionic emulsifiers are also bis (phenoylsulfonsäure) ether or their alkali metal or ammonium salts, which on one or both aromatic rings a C₄-C₂₄-Alkyl group, suitable. These compounds are well known, for. From US-A-4,269,749, and commercially available, for example as Dowfax® 2A1 (Dow Chemical Company).

Suitable cationic emulsifiers are preferably quaternary ammonium halides, e.g. B. trimethylcetylammonium chloride, methyltrioctylammonium chloride, benzyltriethylammonium chloride or quaternary compounds of NC₆-C₂₀-Alkylpyridines, -morpholines or -imidazoles, e.g. B. N-Laurylpyridinium chloride.

Suitable protective colloids are for. B. Polyvinyl alcohols and partially hydrolyzed polyvinyl acetates, polyvinyl propionates, polyacrylates, polyvinylpyrrolidone, copolymers of two or more of the aforementioned polymers forming monomers, cellulose and cellulose derivatives, such as. B. Methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, starch and starch derivatives, such as. B. Cyanalkyletherstärke, hydroxyalkyl ether starch and carboxymethyl starch, proteins and protein degradation products, such as. B. Gelatin and gelatin derivatives etc. A detailed description of protective colloids can be found in Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, Macromolecular Materials, Georg-Thieme-Verlag, Stuttgart, 1961, S. 411-420.

At least one protective colloid is preferably used to prepare the polymer dispersions according to the invention with dispersing aids. These are in particular copolymers of vinylpyrrolidone and vinyl acetate or vinyl propionate, the z. B. as Collacral® brands of BASF Aktiengesellschaft are available.

The curable aqueous polymer dispersions of the invention are preferably suitable for the production of coatings, for. B. of flexible and optionally absorbent substrates such as paper, cardboard, leather or non-flexible substrates made of metal or plastic. Preferably, they are suitable for the production of high-quality, scratch-resistant and chemical-resistant lacquer coatings on wood. In this case, even after evaporation of the water without crosslinking tack-free, dust-dry films with good mechanical resistance, such. B. a high hardness and / or a good flexibility. Thus, the pendulum hardness, measured according to DIN 53157 of a 20 minutes at 60 ° C dried film is at least 20 s, preferably at least 25 s.

If the films which have not yet been radiation-cured are examined for their freedom from tack, substantially no damage to the coating occurs.

The crosslinking of the polyurethanes can be carried out with high-energy radiation such as UV, electron, X-ray or γ radiation. In this case, UV curing is particularly preferred. You can, if desired, in the presence of conventional photoinitiators, such as. B. aromatic ketone compounds such as benzophenone, alkylbenzophenones, Michler's ketone, anthrone, halogenated benzophenones, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phenylglyoxylic acid esters, anthraquinone and its derivatives, benzil ketals, hydroxyalkylphenones, etc. respectively. In this case, mixtures of these compounds can be used. The amount used of the photoinitiators is generally about 0.01 to 20 wt .-%, preferably 0.1 to 10 wt .-%, based on the solids content of the components to be cured.

If desired, the curing of the aqueous polymer dispersions can also be effected by free-radical thermal addition of the customary polymerization initiators. These include all decomposing under the curing conditions into radicals compounds such. B. Peroxides, hydroperoxides, hydrogen peroxide, persulfates, azo compounds and the so-called redox catalysts. Preference is given to the use of water-soluble initiators. In this case, mixtures of different polymerization initiators, for. B. Mixtures of hydrogen peroxide and sodium or potassium peroxodisulfate are used. As initiators suitable organic peroxides z. B. in EP-A-536 597. The amount of polymerization initiators used is generally about 0.01 to 5 wt .-%, based on the amount of polyurethanes to be polymerized. Also suitable as initiators are redox catalysts which are used as oxidizing components, eg. B. at least one of the abovementioned per-compounds and as a reducing component z. B. Ascorbic acid, glucose, sorbose, ammonium or alkali metal bisulfite, thiosulfate, hyposulfite, pyrosulfite or sulfide, metal salts such as ferrous ions or silver ions or sodium hydroxymethylsulfoxylate.

The pendulum hardness of a radiation-cured film is generally at least 160 s 1 hour after radiation curing . The UV-cured films obtained with the polyurethane dispersions according to the invention show substantially no deterioration in the pendulum hardness following the radiation curing. For example, the pendulum hardness is generally at least 160 s even 12 hours after radiation hardening. To determine the flexibility, the Erichsen indentation was determined according to DIN 53156. Surprisingly, even when using an aromatic polyisocyanate, such as tolylene diisocyanate, as component F), films with a good flexibility are obtained. The Erichsentiefung a radiation-cured film of a polymer dispersion based on a polymer according to the invention is then 24 hours after UV curing generally at least 4.0, preferably at least 5.0.

The films obtained from the curable polymer dispersions of the invention are generally scratch resistant. Thus, the pencil hardness of the films after radiation curing is at least 3H, preferably at least 4H.

The polymer dispersions of the invention can be applied by conventional methods such as spraying, rolling, knife coating, pouring, brushing or dipping on a wide variety of substrates. The polymer dispersions of the invention may be used as the sole paint binder or with customary in paint technology additives such. As binders, excipients, pigments, dyes or matting agents are combined.

Another object of the invention are coating compositions comprising at least one inventive polymer or an aqueous polymer dispersion. These coating compositions may optionally comprise a solvent mixture of water and at least one of the aforementioned water-miscible solvents. Preferably, these coating agents are substantially free of organic solvents.

The invention will be explained in more detail with reference to the following, non-limiting examples.

Examples

The hydroxyl number is defined as mg KOH / g product. A suitable method for determining the hydroxyl number is z. By J. Makes and J. Horky in paint and varnish, 94.Jhrg. (1988), s. 898 ff., Described. The determination can also be made titrimetrically according to the following rule:<ul id="ul0007" list-style="none"><li>1. tools and Accessoires<ul id="ul0008" list-style="none" compact="compact"><li>Laboratory balance Measuring accuracy 0,01 g</li><li>Beakers 125 ml</li><li>Titroprocessor 636 (Metrohm)</li><li>Dosimat E 635, Dosimat 665 (Metrohm)</li><li>0.25 N methanolic KOH, acetic anhydride 5% in THF dioxane (ratio 1: 1), 4-dimethylaminopyridine (DMAP) 1% in THF dioxane</li></ul></li><li>Second execution<ul id="ul0009" list-style="none"><li>2.1 blank value 10 ml of DMAP solution are added to the Dosimaten in a clean beaker and then added to 5 ml of acetic anhydride solution. Then allow to react covered for 5 minutes and add 1 ml of deionized water. After a further 10 minutes, 100 ml of a mixture of THF-dioxane (ratio 1: 1) are added and then titrated with a 0.25 N methanolic KOH.</li><li>2.2 sample Approximately 1 g of sample and 10 ml of 4-dimethylaminopyridine solution are added to the Dosimaten 665 in a beaker. Then, 5 ml of acetic anhydride solution are added and the solutions allowed to react for 5 minutes. After adding 100 ml of THF-dioxane (ratio 1: 1), titrate with a 0.25 n methanolic KOH.</li></ul></li><li>Third evaluation<maths id="math0001" num=""><math display="block"><mrow><mtext>OH number [mg KOH / g substance] = </mtext><mfrac><mrow><mtext>(Blank value ml - consumption of sample ml) * 56.1 g / mol * 0.25 n * titer KOH</mtext></mrow><mrow><mtext>Weighed in g (solids)</mtext></mrow></mfrac></mrow></math><img file="EP1069144A2_D0003.tif" /></maths> The content of polar, functional groups, ie the carboxyl, phosphonate, sulfonate content was determined by the weight of component B).</li></ul>

A) Polyurethane production

In a 4-necked flask equipped with stirrer, dropping funnel, thermometer and reflux condenser, hydroxyl-containing unsaturated prepolymer according to Table 1 with the stated in Table 2 amounts of dimethylolpropionic acid, optionally chain extender, acetone and dibutyltin dilaurate were presented and heated to reflux. Then, a diisocyanate was added dropwise in a proportion of Table 2 within one hour. At reflux temperature, the reaction mixture was stirred until the isocyanate group content of the mixture remained virtually constant. It was then cooled to 40 ° C and neutralized with the specified in Table 2 amount of triethylamine. After cooling to ambient temperature, the polyurethane solution was added with vigorous stirring to a mixture of ethylenediamine in water according to Table 2, spontaneously forming a dispersion. The acetone was then distilled off in vacuo at 40 ° C and the dispersion was finally adjusted by dilution with water to the desired solids content. The properties of the dispersions are shown in Table 3. <tables id="tabl0001" num="0001"><table frame="all"><title>Table 1</title><tgroup cols="2" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><thead valign="top"><row><entry namest="col1" nameend="col2" align="center">Hydroxyl-containing prepolymers</entry></row><row><entry namest="col1" nameend="col1" align="center">prepolymer</entry><entry namest="col2" nameend="col2" align="center">Type</entry></row></thead><tbody valign="top"><row rowsep="0"><entry namest="col1" nameend="col1" morerows="1" rowsep="1" align="left">A</entry><entry namest="col2" nameend="col2" align="left">46 Wt .-% polyether acrylate</entry></row><row><entry namest="col2" nameend="col2" align="left">54 Wt .-% bisphenol A diglycidyl ether diacrylate</entry></row><row rowsep="0"><entry namest="col1" nameend="col1" morerows="1" rowsep="1" align="left">B</entry><entry namest="col2" nameend="col2" align="left">56 Wt .-% polyether acrylate</entry></row><row><entry namest="col2" nameend="col2" align="left">44 % By weight of triglycidyl isocyanurate triacrylate</entry></row><row rowsep="0"><entry namest="col1" nameend="col1" morerows="1" rowsep="1" align="left">C</entry><entry namest="col2" nameend="col2" align="left">50 % By weight of polyether acrylate</entry></row><row><entry namest="col2" nameend="col2" align="left">50 % By weight (bis-epoxycyclohexylmethylcarboxylate) diacrylate</entry></row><row rowsep="0"><entry namest="col1" nameend="col1" morerows="1" rowsep="1" align="left">D</entry><entry namest="col2" nameend="col2" align="left">50 % By weight of polyether acrylate</entry></row><row rowsep="1"><entry namest="col2" nameend="col2" align="left">50 % By weight of cyclohexane dimethyl diglycidyl ether diacrylate</entry></row></tbody></tgroup></table></tables>

The prepolymers have OH numbers greater than 120 mg KOH / g.<tables id="tabl0002" num="0002"><img file="EP1069144A2_D0004.tif" /></tables><tables id="tabl0003" num="0003"><img file="EP1069144A2_D0005.tif" /></tables><tables id="tabl0004" num="0004"><img file="EP1069144A2_D0006.tif" /></tables>

B) Properties of the polymer dispersion

The solids content of the aqueous polymer dispersions was determined according to DIN 53216 Part 1 (1 h, 125 ° C).

The viscosity was in a Rheomat 30 according to DIN 53019 at a temperature of 23 ° C and a shear rate D = 250 s^-1 certainly.

The properties of the dispersions are shown in Table 3. <tables id="tabl0005" num="0005"><table frame="all"><title>Table 3</title><tgroup cols="3" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col3" align="center">Properties of the dispersions</entry></row><row><entry namest="col1" nameend="col1" align="center">Example no.</entry><entry namest="col2" nameend="col2" align="center">Solids content [%]</entry><entry namest="col3" nameend="col3" align="center">Viscosity [mPas]</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="center">V1</entry><entry namest="col2" nameend="col2" align="center">36</entry><entry namest="col3" nameend="col3" align="center">1667</entry></row><row><entry namest="col1" nameend="col1" align="center">1^a)</entry><entry namest="col2" nameend="col2" align="center">40</entry><entry namest="col3" nameend="col3" align="center">3359</entry></row><row><entry namest="col1" nameend="col1" align="center">2^a)</entry><entry namest="col2" nameend="col2" align="center">38</entry><entry namest="col3" nameend="col3" align="center">2986</entry></row><row><entry namest="col1" nameend="col1" align="center">V2</entry><entry namest="col2" nameend="col2" align="center">38</entry><entry namest="col3" nameend="col3" align="center">2289</entry></row><row><entry namest="col1" nameend="col1" align="center">3</entry><entry namest="col2" nameend="col2" align="center">40</entry><entry namest="col3" nameend="col3" align="center">55.5</entry></row><row><entry namest="col1" nameend="col1" align="center">V3</entry><entry namest="col2" nameend="col2" align="center">no stable dispersion could be obtained</entry><entry namest="col3" nameend="col3" align="center">not definable</entry></row><row><entry namest="col1" nameend="col1" align="center">4</entry><entry namest="col2" nameend="col2" align="center">40</entry><entry namest="col3" nameend="col3" align="center">2065</entry></row><row><entry namest="col1" nameend="col1" align="center">V4</entry><entry namest="col2" nameend="col2" align="center">no stable dispersion could be obtained</entry><entry namest="col3" nameend="col3" align="center">not definable</entry></row><row><entry namest="col1" nameend="col1" align="center">5</entry><entry namest="col2" nameend="col2" align="center">30</entry><entry namest="col3" nameend="col3" align="center">466.5</entry></row><row><entry namest="col1" nameend="col1" align="center">6</entry><entry namest="col2" nameend="col2" align="center">40</entry><entry namest="col3" nameend="col3" align="center">1,079.8</entry></row><row><entry namest="col1" nameend="col1" align="center">V5</entry><entry namest="col2" nameend="col2" align="center">47</entry><entry namest="col3" nameend="col3" align="center">not definable</entry></row><row><entry namest="col1" nameend="col1" align="center">7</entry><entry namest="col2" nameend="col2" align="center">50</entry><entry namest="col3" nameend="col3" align="center">544.2</entry></row><row><entry namest="col1" nameend="col1" align="center">V6</entry><entry namest="col2" nameend="col2" align="center">40</entry><entry namest="col3" nameend="col3" align="center">845.9</entry></row><row><entry namest="col1" nameend="col1" align="center">8th</entry><entry namest="col2" nameend="col2" align="center">40</entry><entry namest="col3" nameend="col3" align="center">119.5</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="center">9</entry><entry namest="col2" nameend="col2" align="center">40</entry><entry namest="col3" nameend="col3" align="center">91.7</entry></row></tbody></tgroup><tgroup cols="3" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><tbody valign="top"><row><entry namest="col1" nameend="col3" align="justify">^a) When diluted to a solids content of 36%, these dispersions show a viscosity of &lt;1667 mPas.</entry></row></tbody></tgroup></table></tables>

The polyurethane polymers according to the invention can be formulated into polymer dispersions having good performance properties. In particular, these dispersions generally have high solids contents and lower viscosities than corresponding dispersions based on polymers in whose preparation the isocyanate-reactive groups have been reacted to 100%.

Dried and UV-cured films based on the polyurethane polymers of the invention also have good performance properties, eg. High pendulum hardnesses, high pencil hardnesses and low Erichsen depth values.