Latent curing aqueous polyurethane dispersions

The present invention relates to latent crosslinking aqueous polyurethane dispersions containing<ul id="ul0001" list-style="none" compact="compact"><li>1. Containing latent crosslinking aqueous polyurethane dispersions<ul id="ul0002" list-style="none"><li>I) containing a disperse phase (PI)<ul id="ul0003" list-style="none"><li>Ia) a polyurethane (PUR.Ia) which, in addition to groups which bring about the water-dispersibility of the polyurethane, carries groups with a CC double bond in which the double bond is activated by a carbonyl group bonded directly to it</li><li>Ib) a mixture of<ul id="ul0004" list-style="dash"><li>a polyurethane (PUR.Ib) which carries groups which bring about the water-dispersibility of the polyurethane, but not groups with a CC double bond in which the double bond is activated by a carbonyl group directly attached to it, and</li><li>a compound (VI) different from the polyurethanes PUR.Ia and PUR.Ib which carries groups with a CC double bond in which the double bond is activated by a carbonyl group directly attached to it and</li></ul></li></ul></li><li>II) a disperse phase (P.II) containing a compound different from the compounds (PUR.Ia), (PUR.Ib) and (VI), which has several groups selected from the group of thiol groups, primary amino groups or secondary amino groups , wearing.</li></ul></li></ul>

The invention further relates to their use as a coating agent or adhesive.

Aqueous dispersions which contain a polyurethane in dispersed form are generally known. To ensure that coatings made from the polyurethane have particularly good mechanical properties, a crosslinker component is added to these dispersions. It is particularly desirable that the crosslinker does not bring about the molecular weight build-up of the polyurethane until the polyurethane dispersion has already been filmed after application to the workpiece to be coated. Under these circumstances, films are obtained which have a particularly high cohesion, since the polymer molecules of one dispersion particle can then also be linked to the polymer molecules of another neighboring dispersion particle via a covalent bond.

Particularly good cohesion of the films is particularly necessary in the adhesive field, for example, when the adhesive bond is subjected to mechanical stress under the action of heat.

In order to obtain adhesive composites that still have sufficient strength even under these conditions, z. For example, EP-A-206059 recommends adding a water-emulsifiable polyisocyanate to the dispersions shortly before they are processed as an adhesive as a crosslinking agent.

The disadvantage of these two-component systems, however, is that the pot life, ie the period in which these systems can be processed after they have been mixed, is narrowly limited. Since the two-component system cannot be stored over a long period of time and the processor has to produce a certain amount of adhesive that he can process within a working cycle, the workload for the processor of the adhesives in two-component systems is increased compared to one-component systems .

EP-A-442 652 is known for example from EP-A-442 652, which can be stored over a longer period of time, latent curing dispersions, ie those dispersions which contain the hardener, but the hardener only becomes fully effective after the dispersions have been processed. The dispersions contain, for example, a polyurethane with a carbonyl group in aldehyde or keto function and adipic acid dihydrazide as a crosslinking agent. However, these dispersions need improvement in terms of strength at elevated temperatures.

From EP-A-443 537 aqueous dispersions made of polyurethanes are known which carry acryloyl groups. It is recommended to use these dispersions for film lamination. The dispersion is applied to a film, the film is glued to another substrate and the adhesive is cured by irradiation with UV light.

Furthermore, polyurethane dispersions with acryloyl groups are known from EP-A-443 537, 183 119, 181 486, 189 945 and 353 797.

From EP-419 945 the crosslinking of water-dispersed NCO-terminated polyurethane prepolymers with pentaethylene hexamine is known, with the formation of urea groups.

In the unpublished German patent application file number 1960 86 10.8, dispersions are known which carry polyurethane in separate phases, the CC 'double bonds which are activated on carbonyl groups or mixtures of a polyurethane with another polymer which carries such groups (phase I) and contains a water-poorly soluble polyamine (phase II).

The object of the present invention was therefore to provide a further latent curing aqueous polyurethane dispersion which does not have the disadvantages of the prior art and in particular has good storage stability and with which heat-resistant bonds can be produced.

Accordingly, the aqueous dispersions defined at the outset were found.

The disperse phase (P.Ia) usually contains 0.05 to 3, preferably 0.2 to 1 mol / kg groups with a CC double bond, in which the double bond is activated by a carbonyl group bonded directly to it.

The phase (PI) preferably contains or particularly preferably consists of a polyurethane (PUR.Ia) composed of<ul id="ul0005" list-style="none"><li>a1) polyvalent isocyanates with 4 to 30 C atoms,</li><li>a2) Polyols, of which<ul id="ul0006" list-style="none"><li>a2.1) 10 to 100 mol%, based on the total amount of polyols (a2), have a molecular weight of 500 to 5000, and</li><li>a2.2) 0 to 90 mol%, based on the total amount of polyols (a2), have a molecular weight of 60 to 50 g / mol,</li></ul></li><li>a3) monomers different from the monomers (a1) and (a2) with at least one isocyanate group or at least one group which is reactive toward isocyanate groups and which, moreover, carry at least one hydrophilic group or a potentially hydrophilic group, thereby causing the water dispersibility of the polyurethanes,</li><li>a4) Monomers different from the monomers (a1), (a2) and (a3) ​​with at least one isocyanate group or at least one group which is reactive toward isocyanate groups, and which additionally have at least one group with a CC double bond in which the double bond is bonded directly to it Carbonyl group is activated, wear,</li><li>a5) optionally further polyvalent compounds which differ from the monomers (a2) to (a4) and have groups which are reactive toward isocyanate groups and which are alcoholic hydroxyl groups or primary or secondary amino groups.</li></ul>

Suitable monomers (a1) are the polyisocyanates customarily used in polyurethane chemistry.

Particular mention should be made of diisocyanates X (NCO)₂, wherein X stands for an aliphatic hydrocarbon residue with 4 to 12 carbon atoms, a cycloaliphatic or aromatic hydrocarbon residue with 6 to 15 carbon atoms or an araliphatic hydrocarbon residue with 7 to 15 carbon atoms. Examples of such diisocyanates are tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 1-isocyanato-3,5,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), 2,2-bis (4-isocyanatocyclohexyl) propane, trimethylhexane diisocyanate , 1,4-diisocyanatobenzene, 2,4'-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanato-diphenylmethane, 2,4-diisocyanato-diphenylmethane, p-xylylene diisocyanate, the isomers of bis (4-isocyanatocyclohexyl) methane such as the trans / trans, the cis / cis and the cis / trans isomer and mixtures consisting of these compounds.

The mixtures of the respective structural isomers of diisocyanatotoluene and diisocyanatodiphenylmethane are particularly important as mixtures of these isocyanates, in particular the mixture of 80 mol% of 2,4 diisocyanatotoluene and 20 mol% of 2,6-diisocyanatotoluene is suitable. Furthermore, the mixtures of aromatic isocyanates such as 2,4 diisocyanatotoluene and / or 2,6-diisocyanatotoluene with aliphatic or cycloaliphatic isocyanates such as hexamethylene diisocyanate or IPDI are particularly advantageous, the preferred mixing ratio of the aliphatic to aromatic isocyanates being 4: 1 to 1: 4.

As compounds (a1) it is also possible to use isocyanates which, in addition to the free isocyanate groups, carry further blocked isocyanate groups, for example uretdione or carbodiimide groups.

If appropriate, those isocyanates can also be used which carry only one isocyanate group. In general, their proportion is at most 10 mol%, based on the total molar amount of the monomers. The monoisocyanates usually carry further functional groups, such as olefinic groups or carbonyl groups, and are used to introduce functional groups into the polyurethane which enable the polyurethane to be dispersed or crosslinked or to undergo further polymer-analogous conversion. Monomers such as isopropenyl-α, α-dimethylbenzyl isocyanate (TMI) are suitable for this.

To produce polyurethanes with a certain degree of branching or crosslinking, for example, trivalent and tetravalent isocyanates can be used. Such isocyanates are obtained, for example, by reacting divalent isocyanates with one another by derivatizing part of their isocyanate groups to give allophanate or isocyanurate groups. Commercially available compounds are, for example, the isocyanurate or the biuret of hexamethylene diisocyanate.

With regard to good film formation and elasticity, the polyols (a2) used are primarily higher molecular weight polyols (a2.1), preferably diols, which have a molecular weight of approximately 500 to 5000, preferably approximately 100 to 3000 g / mol.

The diols (a2.1) are, in particular, polyester polyols which are known, for example, from Ullmanns Encyklopadie der Technische Chemie, 4th edition, volume 19, pages 62 to 65. Polyester polyols are preferably used, which are obtained by reacting dihydric alcohols with dihydric carboxylic acids. Instead of the free polycarboxylic acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or their mixtures can also be used to prepare the polyester polyols. The polycarboxylic acids can be aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic and optionally, for example by halogen atoms, substituted and / or unsaturated. Examples include: suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylene tetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, fatty acid, maleic acid, maleic acid, fatty acid, maleic acid, in, in Dicarboxylic acids of the general formula HOOC- (CH₂)_y-COOH, where y is a number from 1 to 20, preferably an even number from 2 to 20, for example succinic acid, adipic acid, dodecanedicarboxylic acid and sebacic acid.

Examples of polyhydric alcohols are ethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,3-diol, butene-1,4-diol, butyne-1,4-diol, pentane-1 , 5-diol, neopentyl glycol, bis (hydroxymethyl) cyclohexanes such as 1,4-bis (hydroxymethyl) cyclohexane, 2-methyl-propane-1,3-diol, methylpentanediols, also diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol , Polypropylene glycol, dibutylene glycol and polybutylene glycols. Alcohols of the general formula HO- (CH₂)_x-OH, where x is a number from 1 to 20, preferably an even number from 2 to 20. Examples include ethylene glycol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol and dodecane-1,12-diol.

Also suitable are polycarbonate diols, such as can be obtained, for example, by reacting phosgene with an excess of the low molecular weight alcohols mentioned as structural components for the polyester polyols.

Lactone-based polyester diols are also suitable, these being homopolymers or copolymers of lactones, preferably addition products of lactones with terminal hydroxyl groups onto suitable difunctional starter molecules. Preferred lactones are those which differ from compounds of the general formula HO- (CH₂)_e.g.Derive -COOH, where z is a number from 1 to 20. Examples are ε-caprolactone, β-propiolactone, gamma-butyrolactone and / or methyl-ε-caprolactone and mixtures thereof. Suitable starter components are, for example, the low molecular weight dihydric alcohols mentioned above as the structural component for the polyester polyols. The corresponding polymers of epsilon-caprolactone are particularly preferred. Lower polyester diols or polyether diols can also be used as starters for the preparation of the lactone polymers. Instead of the polymers of lactones, the corresponding, chemically equivalent polycondensates of the hydroxycarboxylic acids corresponding to the lactones can also be used.

In addition, the monomers (a2.1) are polyether diols. They are in particular by polymerization of ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with themselves, for example in the presence of BF₃ or by addition of these compounds, optionally in a mixture or in succession, to starting components with reactive hydrogen atoms, such as alcohols or amines, for example water, ethylene glycol, propane-1,2-diol, propane-1,3-diol, 1,2-bis (4th -hydroxydiphenyl) propane or aniline available. Polytetrahydrofuran with a molecular weight of 240 to 5000, and especially 500 to 4500, is particularly preferred.

Also suitable are polyhydroxyolefins, preferably those with 2 terminal hydroxyl groups, for example α-Ω-dihydroxypolybutadiene, α-Ω-dihydroxypolymethacrylic ester or α-Ω-dihydroxypolyacrylic ester as monomers (a2.1). Such compounds are known, for example, from EP-A-0 622 378. Other suitable polyols are polyacetals, polysiloxanes and alkyd resins.

The polyols can also be used as mixtures in a ratio of 0.1: 1 to 1: 9.

The hardness and the modulus of elasticity of the polyurethanes can be increased if, in addition to the diols (a2.1), low molecular weight diols (a2.2) with a molecular weight of about 62 to 500, preferably from 62 to 200 g / mol, as diols (a2) , are used. The structural components of the short-chain alkanediols mentioned for the production of polyester polyols are primarily used as monomers (a2.2), the unbranched diols having 2 to 12 C atoms and an even number of C atoms being preferred.

The proportion of the diols (a2.1), based on the total amount of the diols (a2), is preferably 10 to 100 mol% and the proportion of the monomers (a2.2), based on the total amount of the diols (a2), is 0 up to 90 mol%. used. The ratio of the diols (a2.1) to the monomers (a2.2) is particularly preferably 0.2: 1 to 5: 1, particularly preferably 0.5: 1 to 2: 1.

In order to achieve the water dispersibility of the polyurethanes, in addition to components (a1) and (a2), the polyurethanes are composed of monomers (a3) ​​which differ from components (a1) and (a2), which have at least one isocyanate group or at least one group which is reactive toward isocyanate groups and furthermore, at least one hydrophilic group or a group which can be converted into hydrophilic groups is built up. In the following text, the term "hydrophilic groups or potentially hydrophilic groups" is abbreviated to "(potentially) hydrophilic groups". The (potentially) hydrophilic groups react with isocyanates much more slowly than the functional groups of the monomers, which serve to build up the main polymer chain.

The proportion of components with (potentially) hydrophilic groups in the total amount of components (a1) to (a5) is generally such that the molar amount of (potentially) hydrophilic groups, based on the amount by weight of all monomers (a1) to (a5 ), 0.03 to 1, preferably 0.05 to 0.5 and particularly preferably 0.08 to 0.3 mol / kg.

The (potentially) hydrophilic groups can be nonionic or preferably (potentially) ionic hydrophilic groups.

Particularly suitable nonionic hydrophilic groups are polyethylene glycol ethers of preferably 5 to 100, preferably 10 to 80, repeating ethylene oxide units. The content of polyethylene oxide units is generally 0 to 10, preferably 0 to 6,% by weight, based on the amount by weight of all monomers (a1) to (a5).

Preferred monomers with nonionic hydrophilic groups are polyethylene glycol and diisocyanates, which carry a terminally etherified polyethylene glycol residue. Such diisocyanates and processes for their preparation are specified in the patents US 3 905 929 and US 3 920 598.

Ionic hydrophilic groups are above all anionic groups such as the sulfonate, carboxylate and phosphate groups in the form of their alkali metal or ammonium salts, and also cationic groups such as ammonium groups, in particular protonated tertiary amino groups or quaternary ammonium groups.

Potentially ionic hydrophilic groups are, above all, those which can be converted into the above-mentioned ionic hydrophilic groups by simple neutralization, hydrolysis or quaternization reactions, that is to say, for example, carboxylic acid groups, anhydride groups or tertiary amino groups.

(Potentially) ionic monomers (a3) ​​are described in detail, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 4th edition, volume 19, pages 311-313 and, for example, in DE-A 1 495 745.

As (potentially) cationic monomers (a3), especially monomers with tertiary amino groups are of particular practical importance, for example: tris (hydroxyalkyl) amines, N, N'-bis (hydroxyalkyl) alkylamines, N-hydroxyalkyl dialkylamines, tris - (Aminoalkyl) amines, N, N'-bis (aminoalkyl) alkylamines, N-aminoalkyl dialkylamines, where the alkyl radicals and alkanediyl units of these tertiary amines independently of one another consist of 2 to 6 carbon atoms. Furthermore, polyethers having tertiary nitrogen atoms and preferably having two terminal hydroxyl groups, such as are obtainable in a conventional manner, for example by alkoxylation of two amines containing hydrogen atoms bonded to amine nitrogen, for example methylamine, aniline, or N, N'-dimethylhydrazine. Such polyethers generally have a molecular weight between 500 and 6000 g / mol.

These tertiary amines are either with acids, preferably strong mineral acids such as phosphoric acid, sulfuric acid or hydrohalic acids or strong organic acids or by reaction with suitable quaternizing agents such as C.₁- to C₆Alkyl halides, for example bromides or chlorides, are converted into the ammonium salts.

Monomers with (potentially) anionic groups are usually aliphatic, cycloaliphatic, araliphatic or aromatic carboxylic acids and sulfonic acids which carry at least one alcoholic hydroxyl group or at least one primary or secondary amino group. Dihydroxyalkylcarboxylic acids are preferred, especially those with 3 to 10 carbon atoms, as are also described in US Pat. No. 3,412,054. In particular, compounds of the general formula<chemistry id="chem0001" num="0001"><img file="EP0807648A2_D0001.tif" /></chemistry> in which R¹ and R² for a C₁- to C₄-Alkanediyl unit and R³ for a C₁- to C₄-Alkyl unit and especially dimethylolpropionic acid (DMPA) is preferred.

Corresponding dihydroxysulfonic acids and dihydroxyphosphonic acids such as 2,3-dihydroxypropanephosphonic acid are also suitable.

Otherwise suitable are dihydroxyl compounds with a molecular weight above 500 to 10,000 g / mol with at least 2 carboxylate groups, which are known from DE-A 3 911 827. They are obtainable by reacting dihydroxyl compounds with tetracarboxylic dianhydrides such as pyromellitic dianhydride or cyclopentantetracarboxylic dianhydride in a molar ratio of 2: 1 to 1.05: 1 in a polyaddition reaction. Particularly suitable dihydroxyl compounds are the monomers (a2.2) listed as chain extenders and the diols (a2.1).

Suitable monomers (a3) ​​with amino groups reactive towards isocyanates are amino carboxylic acids such as lysine, β-alanine, the adducts of aliphatic diprimeric diamines with α, β-unsaturated carboxylic acids such as N- (2-aminoethyl) mentioned in DE-A 2 034 479. -2-aminoethane carboxylic acid and the corresponding N-aminoalkylaminoalkylcarboxylic acids, where the alkanediyl units consist of 2 to 6 carbon atoms.

If monomers with potentially ionic groups are used, they can be converted into the ionic form before, during, but preferably after the isocyanate polyaddition, since the ionic monomers are often difficult to dissolve in the reaction mixture. The carboxylate groups are particularly preferably in the form of their salts with an alkali ion or an ammonium ion as counterion.

The monomers (a4) which differ from the monomers (a2) and (a3) ​​are, in particular, compounds having one, preferably 2 alcoholic hydroxyl groups such as (C₁- to C₆-Hydroxyalkyl) -acrylates, e.g. hydroxyethyl acrylate and hydroxypropyl acrylate, a (C₁- to C₆Hydroxyalkyl) methacrylate, mono- or diester of acrylic acid or methacrylic acid and trimethylolpropane or glycerol or the bis-adduct of acrylic acid and / or methacrylic acid with a bisepoxide such as Bisphenol® A and bisphenol F.

Furthermore, the adduct of acrylic or methacrylic acid and butanediol diglycidyl ether is particularly suitable.

Also suitable as monomers (a4) are conventional polyester polyols which are at least partially composed of maleic acid and fumaric acid. Otherwise, these polyesters are constructed in exactly the same way as the polyesters which are suitable as monomers (a2.2).

The monomers (a5) which may be used as structural components and which differ from the monomers (a2) to (a4) generally serve for crosslinking or chain extension. They are generally more than dihydric non-aromatic alcohols, amines with 2 or more primary and / or secondary amino groups and compounds which carry one or more alcoholic hydroxyl groups and one or more primary and / or secondary amino groups.

Alcohols with a higher valence than 2, which can serve to establish a certain degree of branching or crosslinking, are, for example, trimethylolpropane, glycerol or sugar.

Also suitable are monoalcohols which, in addition to the hydroxyl group, carry a further group which is reactive toward isocyanates, such as monoalcohols having one or more primary and / or secondary amino groups, for example monoethanolamine.

Polyamines with 2 or more primary and / or secondary amino groups are used above all if the chain extension or crosslinking is to take place in the presence of water, since amines generally react faster with isocyanates than alcohols or water. This is often necessary when aqueous dispersions of cross-linked polyurethanes or high molecular weight polyurethanes are desired. In such cases, the procedure is to prepare prepolymers with isocyanate groups, to disperse them rapidly in water and then to extend or crosslink them by adding compounds having several isocyanate-reactive amino groups.

Amines suitable for this purpose are generally polyfunctional amines in the molecular weight range from 32 to 500 g / mol, preferably from 60 to 300 g / mol, which contain at least two primary, two secondary or one primary and one secondary amino group. Examples include diamines such as diaminoethane, diaminopropane, diaminobutane, diaminohexane, piperazine, 2,5-dimethylpiperazine, amino-3-aminomethyl-3,5,5-trimethyl-cyclohexane (isophorone diamine, IPDA), 4,4'-diaminodicyclohexylmethane, 1 , 4-diaminocyclohexane, aminoethylethanolamine, hydrazine, hydrazine hydrate or triamines such as diethylenetriamine or 1,8-diamino-4-aminomethyloctane.

The amines can also be used in blocked form, for example in the form of the corresponding ketimines (see, for example, CA-1 129 128), ketazines (see, for example, US Pat. No. 4,269,748) or amine salts (see US Pat. No. 4,292,226) become. Oxazolidines, as are used, for example, in US Pat. No. 4,192,937, are blocked polyamines which can be used for the chain extension of the prepolymers for the production of the polyurethanes according to the invention. When such capped polyamines are used, they are generally mixed with the prepolymers in the absence of water and this mixture is then mixed with the dispersion water or part of the dispersion water, so that the corresponding polyamines are released hydrolytically.

Mixtures of di- and triamines are preferably used, particularly preferably mixtures of isophoronediamine and diethylenetriamine.

The polyurethanes preferably contain no polyamine or 1 to 10, particularly preferably 4 to 8 mol%, based on the total amount of component (a2) to (a4) of a polyamine with at least 2 amino groups reactive towards isocyanates as monomers (a5).

It is advisable to use compounds with primary or secondary amino groups only in such amounts that the total amount of isocyanate groups present at the time of addition is greater than that of the primary or secondary amino groups. Under these circumstances it can be avoided that a larger proportion of the amino groups does not react with the isocyanate groups to form urea, but rather with the acryloyl or methacryloyl groups.

According to a likewise preferred embodiment, the phase (PI) contains or consists of a mixture<ul id="ul0007" list-style="dash"><li>a polyurethane (PUR.Ib) and</li><li>a polyurethane (PUR.Ic) as compound (VI), the polyurethane (PUR.Ib) is made up of<ul id="ul0008" list-style="none"><li>b1) polyvalent isocyanates with 4 to 30 C atoms,</li><li>b2) polyols, of which<ul id="ul0009" list-style="none"><li>b2.1) 10 to 100 mol%, based on the total amount of diols (b2), have a molecular weight of 500 to 5000, and</li><li>b2.2) 0 to 90 mol%, based on the total amount of diols (b), have a molecular weight of 60 to 500 g / mol,</li></ul></li><li>b3) monomers different from the monomers (b1) and (b2) with at least one isocyanate group or at least one group which is reactive toward isocyanate groups and which furthermore carry at least one hydrophilic group or a potentially hydrophilic group, thereby causing the water-dispersibility of the polyurethanes,</li><li>b4) optionally further polyvalent compounds which are different from the polyols (b2) and monomers (b3) and have groups which are reactive toward isocyanates and which are alcoholic hydroxyl groups or primary or secondary amino groups, and the polyurethane (PUR.Ic) is made up of</li><li>c1) polyvalent isocyanates with 4 to 30 C atoms,</li><li>c2) polyols, of which<ul id="ul0010" list-style="none"><li>c2.1) 10 to 100 mol%, based on the total amount of diols (c2), have a molecular weight of 500 to 5000, and</li><li>c2.2) 0 to 90 mol%, based on the total amount of diols (c2), have a molecular weight of 60 to 500 g / mol,</li></ul></li><li>c3) monomers different from the monomers (c1) and (c2) with at least one isocyanate group or at least one group which is reactive towards isocyanate groups and which additionally carry at least one acryloyl or methacryloyl group.</li></ul></li></ul>

The quantitative ratio of polyurethane (PUR.Ib) to compound (VI) is generally 0.5: 1 to 10: 1.

Particularly suitable monomers (b1), (b2), (b3) and (b4) are the corresponding monomers which are preferred as monomers (a1), (a2), (a3) ​​and (a5).

Particularly suitable monomers (c1), (c2.1), (c2.2) and (c3) are the corresponding monomers, which as monomers (a1), (a2.1), (a2.2) and (a4) are preferred.

The monomers (c3) are preferably used in amounts such that the polyurethane (PUR.Ic) 0.2 to 4 mol groups with a CC double bond, in which the double bond is activated by a directly bonded carbonyl group, per kg of polyurethane (PUR .Ic) contains.

The disperse phase (PI) can also contain, as compounds (VI), esters containing acryloyl or methacryloyl groups, as are known from EP-A-447 845, 279 303 or 127 766.

These are preferably esters, obtainable by reacting<ul id="ul0011" list-style="dash"><li>Polyols such as those described as monomers (a2.1) and (a2.2) as well as higher, low molecular weight alcohols such as glycerol, trimethylolpropane and pentaerythrol, these alcohols optionally being ethoxylated or propoxylated,</li><li>2- to 4-valued C₃- to C₃₆-Carboxylic acids, eg adipic acid and</li><li>Acrylic and / or methacrylic acid, to a carboxylic acid-containing polyester, and subsequent esterification of the carboxylic acid groups of these esters by reaction with equivalent amounts of an epoxy compound.</li></ul>

Particularly suitable are compounds (VI) which are at least 5% by weight soluble at 20 ° C. in a solvent in which the polyurethanes (PUR.Ia) are usually produced and 0.1 to 100 g per 100 g 1 mol groups with a CC double bond in which the double bond is activated by a carbonyl group directly attached to it.

Both the polyurethane (PUR.Ia) and the compound (VI) preferably have a solubility in water of less than 5 g / l, particularly preferably less than 1 g / l (measured at 20 ° C.).

It is generally known in the field of polyurethane chemistry how the molecular weight of the polyurethanes can be adjusted by choosing the proportions of the monomers reactive with one another and the arithmetic mean of the number of reactive functional groups per molecule.

Components (a1) to (a5) or (b1) to (b4) and their respective molar amounts are normally chosen so that the ratio A: B with<ul id="ul0012" list-style="none"><li>A) the molar amount of isocyanate groups and</li><li>B) the sum of the molar amount of the hydroxyl groups and the molar amount of the functional groups which can react with isocyanates in an addition reaction 0.5: 1 to 2: 1, preferably 0.8: 1 to 1.5, particularly preferably 0.9 : 1 to 1.2: 1. The ratio A: B is very particularly preferably as close as possible to 1: 1.</li></ul>

The monomers (a4) 0.05 to 3 are preferably used in amounts such that the polyurethane (PUR.Ia) 50 to 1000, particularly preferably 0.2 to 1 mol, groups with a CC double bond in which the double bond is formed by a directly linked carbonyl group is activated, contains per kg of polyurethane (PUR.Ia).

The dispersions according to the invention can be prepared in a simple manner by using a dispersion (DI) containing, in disperse form, a polyurethane having groups with a CC double bond in which the double bond is activated by a directly bonded carbonyl group (disperse phase PI), However, this dispersion (DI) is essentially free of polyurethanes which still carry isocyanate groups with a compound which<ul id="ul0013" list-style="dash"><li>on average at least 2, preferably 5 to 200, particularly preferably 10 to 100 H atoms, which are then present as an amino function</li><li>a water solubility of more than 1 g / l, preferably more than 10 g / l, particularly preferably more than 100 g / l and</li><li>a number average molecular weight (M_n) from 200 to 1,000,000, preferably from 400 to 10,000.</li></ul>

The number average molecular weight can be calculated, for example, from the measured amine number, the determination of which is generally known (cf. DIN. 53176).

Apart from the amino function, the compounds II generally have no groups which can react with water or the phase I polymers. Particularly suitable compounds (II) are poly- (C2-C4) -alkylene oxides which carry amino groups at the chain ends, those which are predominantly listed as ethylene oxide and / or propylene oxide units being preferred.

Such amines are known under the trade name Jeffamine® and are described, for example, in EP-A-507143.

These are, for example, reaction products of a diprimary polyether diamine and 2 moles of ethylene, propylene and / or butylene oxide per mole of polyether diamine, the conditions for the reaction of the polyether diamine with the alkylene oxide being selected so that the N, N 'is highly selective. -Bis (hydroxyalkylamine) derivative with two secondary amino groups. Examples of the polyether diamines are, for example 4,7-dioxadecane-1,10-diamine, 4,11-dioxatetradecane-1,14-diamine, α- (2-aminomethyl-ethyl) -ω- (2-aminomethyl-ethoxy) -poly [oxy (methyl- 1,2-ethanediyl)] with a MW of 200 to 3000, and α- (3-aminopropyl) -ω- (3-aminopropoxy) poly [oxy (1,4-butanediyl)] with a MW of 300 to 3000 .

Preferred compounds (II) are furthermore branched or unbranched polyethyleneimines and one from 200 to 10,000. Such compounds are commercially available (Polymin® brands from BASF AG) and are described, for example, in US 3200081, US 3885069 and DE-A-19611977.

The polyurethanes (PUR Ia) or the compounds (VI) on the one hand and the compounds (II) on the other hand are preferably present in the aqueous dispersions according to the invention in proportions such that the molar ratio of the double bond activated by a carbonyl group to the hydrogen atoms of the compound (II), which is present as an amino group is 0.1: 1 to 10: 1, preferably 2: 1 to 0.5: 1.

Above all, aqueous dispersions according to the invention are preferred in which the molar ratio of the double bond activated by a carbonyl group to the secondary and primary amino groups is 2: 1 to 0.5: 1.

The mixing of the dispersion (DI) with the compound (II) is not critical and can be carried out, for example, by stirring it into the dispersion.

Dispersions (DI) which carry a polyurethane (PUR.Ia) with a CC double bond in which the double bond is activated by a directly bonded carbonyl group, for example acryloyl or methacryloyl groups, are generally known (cf. EP-A-443 537, 183 119, 181 486, 189 945 and 353 797).

Most of the time, the dispersions (DI) are produced by one of the following processes:

According to the "acetone process", a water-dispersible polyurethane is prepared from components (a1) to (a5) or (b1) to (b4) in a water-miscible solvent which boils at 100 ° C. under normal pressure. Sufficient water is added until a dispersion is formed in which water is the coherent phase.

The "prepolymer mixing process" differs from the acetone process in that it does not produce a fully reacted (potentially) water-dispersible polyurethane, but first a water-dispersible prepolymer that carries isocyanate groups. The components (a1) to (a5) or (b1) to (b4) are chosen so that the ratio A: B according to the definition is greater than 1.0 to 3, preferably 1.05 to 1.5. The prepolymer is first dispersed in water and then, if appropriate, crosslinked by reaction of the isocyanate groups with amines which carry more than 2 amino groups reactive towards isocyanates or chain-extended with amines which carry 2 amino groups reactive toward isocyanates. Chain extension also takes place when no amine is added. In this case, isocyanate groups are hydrolyzed to amine groups, which react with remaining isocyanate groups of the prepolymers with chain extension.

In the case of the prepolymer from the monomers (b1) to (b4), the stoichiometric ratio of the starting materials and the reaction time are preferably chosen so that the prepolymer contains less than 0.1% by weight of NCO groups per kg before it is dispersed Contains prepolymer. The weight of the NCO groups is assumed to be 42 g per mole.

The polyaddition of components (a1) to (a5) or (b1) to (b4) is generally carried out at reaction temperatures of 20 to 180 ° C, preferably 50 to 150 ° C under normal pressure or under autogenous pressure.

The required response times can range from a few minutes to a few hours. It is known in the field of polyurethane chemistry how the reaction time is influenced by a large number of parameters such as temperature, concentration of the monomers and reactivity of the monomers.

To accelerate the reaction of the diisocyanates, the customary catalysts, such as dibutyltin dilaurate, stannous octoate or diazabicyclo (2,2,2) octane, can also be used.

Stirred kettles are suitable as polymerization apparatus, in particular if low viscosity and good heat dissipation are ensured by the use of solvents.

Preferred solvents are infinitely miscible with water, have a boiling point at atmospheric pressure of 40 to 100 ° C and do not react or react only slowly with the monomers.

The dispersions (DI), which contain a mixture of the polyurethane (PUR.Ib) and the compound (VI) as the disperse phase (PI), are expediently prepared by using the not yet dispersed polyurethane (PUR.Ib) and in the prepolymer mixing process, the corresponding prepolymer is mixed with the compound (VI) and these mixtures are dispersed in water. This type of codispersion forms a disperse phase in which the polyurethane (PUR.Ib) and the compound (VI) are present next to one another, ie both together in one particle.

This method of codispersion is described, for example, in DE-A-3 903 538, 4 309 079 and 4 0 24 567 using the example of polymers, for example hydrophobic auxiliaries such as phenol condensation resins made from aldehydes and phenol or phenol derivatives or epoxy resins.

Usually, if a solvent was used in the production of the polyurethane, most of the solvent is removed from the dispersion, for example by distillation under reduced pressure. The dispersions preferably have a solvent content of less than 10% by weight and are particularly preferably free from solvents.

These hydrophobic auxiliaries can also be contained in the disperse phase (PI).

The dispersions (DI) generally have a solids content of 10 to 75, preferably 20 to 65% by weight and a viscosity of 10 to 500 mPas (measured at a temperature of 20 ° C. and a shear rate of 250 s^-1).

The polyurethane dispersions according to the invention can contain further water-emulsifiable or -dispersible resins, such as polymer, polyurethane, polyester, epoxy or alkyd resins, and commercially available auxiliaries and additives such as blowing agents, defoamers, emulsifiers, thickeners and thixotropic agents, colorants such as dyes and pigments.

They are suitable, for example, for gluing or coating different substrates such as wood, metal, plastics, paper, leather or textile, as well as for the production of moldings and printing inks.

The processing of the polyurethane dispersions according to the invention can be carried out by the methods generally used in the adhesive, leather or lacquer industry, that is to say by spraying the rollers onto the substrate or knife coating and then drying them.

In the case of processing as an adhesive, the coated workpieces are preferably joined together with another workpiece either before the drying of the dispersion film or after drying, using pressure.

Particularly strong adhesive composites are obtained if workpieces which are provided with a dried adhesive film are heated to a temperature of approx. 50 to 100 ° C immediately before, during or after assembly.

The adhesive composites produced by these methods are characterized in particular by the fact that they are stable in storage and can be used to produce bonds with a high level of heat resistance.

Used as a leather coating, they give the leather a surface that conveys a pleasant, leather-like feeling when it comes into contact with the skin, high mechanical strength and good processing properties, for example when ironing the coated leather.

Manufacturing examples:

The viscosities of the dispersions were measured at a temperature of 20oC and a shear rate of 250s-1 using a rotary rheometer with concentric cylinders (spindle diameter 38.7 mm, cup diameter: 42.0 mm).

The particle size of the latex particles was determined indirectly via turbidity measurements. For this purpose, the turbidity of a dispersion with a solids content of 0.01% by weight was determined relative to dest. Water determined at a layer thickness of 2.5 cm and at room temperature.<maths id="math0001" num=""><math display="block"><mrow><mtext>LD = </mtext><mfrac numalign="left" denomalign="left"><mrow><msub><mrow><mtext>intensity</mtext></mrow><mrow><mtext>Disp.</mtext></mrow></msub><mtext>x100</mtext></mrow><mrow><msub><mrow><mtext>intensity</mtext></mrow><mrow><mtext>water</mtext></mrow></msub></mrow></mfrac></mrow></math><img file="EP0807648A2_D0002.tif" /></maths>

The K value is a measure of the molecular weight of a polymer and was determined using the method as described in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd Edition, Verlag John Wiley &amp; Sons, Inc., Volume 23, p.967 is described.

The symbols used in the examples below have the meanings given below:<dl id="dl0001" compact="compact"><dt>OHZ =</dt><dd>Hydroxyl number</dd><dt>TDI =</dt><dd>Tolylene diisocyanate</dd><dt>HDI =</dt><dd>Hexamethylene diisocyanate</dd><dt>PUD salt =</dt><dd>Na salt of the Michael adduct from acrylic acid and ethylenediamine</dd><dt>DBTL =</dt><dd>Dibutyltin dilaurate</dd><dt>DMPA =</dt><dd>Dimethylol propionic acid</dd><dt>Demineralized water =</dt><dd>Deionized water</dd><dt>RT =</dt><dd>Room temperature</dd><dt>M =</dt><dd>Molecular weight</dd></dl>

Example 1 (V) (for comparison)

565.5 g of a polyester made from adipic acid and butanediol (OHZ = 45) were reacted with 0.05 g DBTL in 152.2 g acetone at 65 ° C with 29.6 g TDI for 1 h. 28.6 g of HDI are metered in and kept at 65 ° C. for a further 37 min. Then diluted with 609.9 g of acetone and cooled to 50 ° C, the NCO content was 0.65%. 40.95 g of PUD salt were added and after a few minutes 160.0 g of an adduct of 2 mol of acrylic acid and 1 mol of bisphenol A bisglycidyl ether were stirred in homogeneously in 160 g of acetone. It was then dispersed with 1200 g of demineralized water. After adding a defoamer, the acetone was distilled off in vacuo at temperatures up to 40 ° C. The dispersion was adjusted to 40% solids.<dl id="dl0002" compact="compact"><dt>Analysis values:</dt><dd>Solids content: 40% LD: 51.8% Visc .: 26.4 mPas pH: 8.81 Double bond content: 0.83 mol / kg</dd></dl>

example 1

A portion of the dispersion was mixed with a 25% aqueous solution of a polyethyleneimine with Pn = 20, so that the same molar amounts of double bonds and amino groups are present.<ul id="ul0014" list-style="none" compact="compact"><li>LD: 62 Visc .: 34.1 mPas pH: 9.3</li></ul> The dispersion was filmed at 40 ° C: K value: undissolved

Example 2 (V) (for comparison)

595.9 g of a polyester composed of adipic acid and diethylene glycol (OHZ = 42) were reacted with 0.1 g DBTL, 50.2 g 1,4-butanediol and 80.1 g TDI in 172 g acetone at 65 ° C. for 1 h. Then 77.4 g of HDI were metered in and the mixture was stirred at 65 ° C. for a further 1.5 h. It was diluted with 688 g of acetone and cooled to 59 ° C. The NCO content is 0.69%. after the addition of 40.95 g of PUD salt, the mixture is stirred for a few minutes and a solution of 80 g of an adduct of 2 mol of acrylic acid and 1 mol of bisphenol A bisglycidyl ether is homogeneously stirred into 80 g of acetone. Then was dispersed with 1200 g of demineralized water. The acetone was distilled off in vacuo at temperatures up to 40 ° C. and the dispersion was adjusted to a solids content of 40%.<dl id="dl0003" compact="compact"><dt>Analysis values:</dt><dd>Solids content: 40% LD: 87.2% Visc .: 121 mPas pH: 8 K value: 85 Double bond content: 0.41 mol / kg</dd></dl>

Example 2

Part of the dispersion was mixed with equimolar amounts of amine in the form of a polyethyleneimine with Pn = 20 as a 50% solution. LD: 83.5 Visc .: 76.2 mPas pH: 9.4 K value: 77

The dispersion was filmed at 40 ° C. K value: undissolved.

Example 3 (V) (for comparison)

641.7 g of a polyester made from adipic acid and butanediol (OHZ = 45) was reacted with 0.03 g DBTL and 31.5 g TDI in 171.7 g acetone at 65 ° C for 1 h. Then 30.4 g of HDI were metered in and kept at 65 ° C. for a further 105 min. It was diluted with 688.2 g of acetone and cooled to 50 ° C.

The NCO content is 0.59%. The chain was lengthened with 40.95 g of PUD salt and after a few minutes it was diluted with 300 g of demineralized water. 80 g of a reaction product of 2 mol of acrylic acid and 1 mol of butanediol bisglycidyl ether (M = 330 g / mol) were stirred in homogeneously. Then was dispersed with 900 g of demineralized water. The acetone is distilled off in vacuo at temperatures up to 40 ° C. and the solids content is adjusted to 40%.<dl id="dl0004" compact="compact"><dt>Analysis values:</dt><dd>Solids content: 40% LD: 89.7 Visc .: 37.6 mPas pH: 7.5 K value 57 Double bond content: 0.6 mol / kg</dd></dl>

Example 3

An equivalent amount of amine in the form of a polyethyleneimine Pn = 20 was added to part of the dispersion as a 25% solution. K value: 55

The dispersion was filmed at 40 ° C. K value: undissolved.

Example 4 (V) (for comparison)

585.3 g of a polyester of adipic acid and diethylene glycol (OHZ = 42) were mixed with 0.5 g DBTL, 21.45 g DMPA, 72.3 g of an adduct of 2 mol acrylic acid with 1 mol butanediol bisglycidyl ether (M = 330 g / mol) and 0.05 g dimethylhydroquinone in 195.5 g Acetone submitted at 40 ° C. 120.9 g of TDI are metered in and converted at 70 ° C. for 277 min. The mixture is then diluted with 782 g of acetone and cooled to 50 ° C., the NCO content is 0.55%. It is neutralized with 25.6 g of 25% sodium hydroxide solution and dispersed with 1200 g of demineralized water. The acetone is distilled off in vacuo at temperatures up to 40 ° C. and the solids content is adjusted to 40%.<dl id="dl0005" compact="compact"><dt>Analysis values:</dt><dd>Solids content: 40% LD: 73 Visc .: 70 mPas pH: 8.6 K value: 39 Double bond content: 0.55 mol / g</dd></dl>

Example 4

A portion of the dispersion was mixed with a polyethyleneimine Pn = 20 as a 25% solution.<ul id="ul0015" list-style="none"><li>Molar ratio of double bonds: amino groups 2: 1.</li><li>K value: 43</li><li>The dispersion was filmed at 40 ° C. K value: undissolved.</li></ul>

Example 5 (V) (for comparison)

465.2 g of polypropylene oxide diol (OHZ = 56) were reacted with 0.5 g of DBTL, 21.4 g of DMPA, 24.2 g of neopentyl glycol and 129.2 g of TDI for 122 min at 110 ° C. The mixture was then diluted with 782 g of acetone and cooled to 50 ° C. It was neutralized with 4.5 g of NaOH in 20 g of demineralized water and 160 g of an adduct of 2 mol of acrylic acid and 1 mol of bisphenol A bisglycidyl ether (M = 484) were stirred in homogeneously in 160 g of acetone. Then was dispersed with 1200 g of demineralized water. The acetone was distilled off in vacuo at temperatures up to 40 ° C. and the solids content was adjusted to 40%.<dl id="dl0006" compact="compact"><dt>Analysis values:</dt><dd>Solids content: 40% LD: 97 Visc .: 417 mPas pH: 8.1 K value: 43 Double bond content: 0.83 mol / kg</dd></dl>

Example 5

A part of the dispersion was mixed with a 25% solution of a polyethyleneimine Pn = 20. Equimolar amounts of amine and double bonds were present.<ul id="ul0016" list-style="none" compact="compact"><li>K value: 47</li></ul>

Example 6 (V) (for comparison)

400 g (0.2 mol) of a polyesterol composed of adipic acid, neopentyl glycol and hexanediol having an OH number of 56, 21.4 g (0.16 mol) of dimethylolpropionic acid and 14.3 g (0.106 mol) of trimethylolpropane were mixed. To this were added 127.2 g (0.73 mol) of tolylene diisocyanate and reacted at 100 ° C. for 90 minutes. The mixture was then cooled to 80 ° C. and 0.37 g of hydroquinone monomethyl ether and 37.2 g (0.32 mol) of hydroxyethyl acrylate were added. After 120 min at 80 ° C., the mixture was diluted with 500 g of acetone. The NCO content is 0.32% by weight (calc. 0.38%). Then 15.1 g (0.15 mol) of triethylamine were mixed in and dispersed by adding 1200 g of water. The acetone was then distilled off in vacuo. A finely divided dispersion with a solids content of 34.0% and a double bond content (DB) of 177 mmol / kg of dispersion was obtained.

Example 6

200 1.0 g of Polymin G 10 (23.3 mmol NH) are added to g of the PUR dispersion (35.2 mmol of DB) and the mixture is adjusted to a solids content of 30% with 29 g of water.

Example 6a

200 2.0 g of Polymin G 10 (46.5 mmol NH) are added to g of the PU dispersion (35.2 mmol of DB) and the mixture is adjusted to a solids content of 30% with 31.5 g of water.

Example 6b

200 5.0 g of Polymin G 10 (116.3 mmol NH) are added to g of the PUR dispersion (35.2 mmol of DB) and the mixture is adjusted to a solids content of 30% with 38.5 g of water.

A Application test as an adhesive

<ul id="ul0017" list-style="none"><li>The dispersions are thickened with 2% Collacral VL and knife-coated onto 5 hardboard sheets (20 cm x 3 cm) with a thickness of 2 mm and dried for 60 min at RT or 3 min at 60 ° C. Then an ASA film or PVC film with 0.5 N / mm2 is pressed on for 30 s at 80 ° C.</li><li>The heat resistance is determined via the peel strength. The heat resistance (WSF) is tested after 24 hours. For this purpose, the ASA film or PVC film is loaded at a peeling angle of 180 ° C with a weight of 300 g. The temperature is increased by 10 ° C every 30 minutes. The highest temperature at which the drainage distance is just less than 50 mm is given as the heat resistance.</li></ul>

The test results are summarized in Table 1 <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="col1" align="center">example</entry><entry namest="col2" nameend="col2" align="left">WSF [° C]</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">1*</entry><entry namest="col2" nameend="col2" align="left">5 x 90</entry></row><row><entry namest="col1" nameend="col1" align="left">1 (V) *</entry><entry namest="col2" nameend="col2" align="left">5 x 60</entry></row><row><entry namest="col1" nameend="col1" align="left">2**</entry><entry namest="col2" nameend="col2" align="left">5 x&gt; 120</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">2nd (V) **</entry><entry namest="col2" nameend="col2" align="left">5 x 90</entry></row></tbody></tgroup><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><tbody valign="top"><row><entry namest="col1" nameend="col2" align="justify">* with PVC film, dried at RT for 60 min</entry></row><row><entry namest="col1" nameend="col2" align="justify">** with ASA film, dried for 3 min at 60 ° C</entry></row></tbody></tgroup></table></tables>

B. Application test as a leather coating

The dispersions mentioned in Table 2 were applied as a finish to primed cow leather.

The fatigue strength test was carried out in accordance with DIN 53 351 / IuP (method of physical leather testing by the international union of leather chemists, associations) with the Bally flexometer).

The wet abrasion was tested with the rub fastness tester according to WESSLIC according to IUF 450 (International Union Fastness). The test was carried out after the storage times of the coated leathers indicated in the table.

The assessment was based on the extent of the damage O no, g minor, d significant s severe damage <tables id="tabl0002" num="0002"><table frame="all"><title>Table 2</title><tgroup cols="6" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="26.25mm" /><colspec colnum="2" colname="col2" colwidth="26.25mm" /><colspec colnum="3" colname="col3" colwidth="26.25mm" /><colspec colnum="4" colname="col4" colwidth="26.25mm" /><colspec colnum="5" colname="col5" colwidth="26.25mm" /><colspec colnum="6" colname="col6" colwidth="26.25mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" rowsep="0" align="center">Examples</entry><entry namest="col2" nameend="col2" align="center">Flex.</entry><entry namest="col3" nameend="col3" align="center">Flex.</entry><entry namest="col4" nameend="col6" align="center">Wet abrasion</entry></row><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="center">dry¹⁾</entry><entry namest="col3" nameend="col3" align="center">wet²⁾</entry><entry namest="col4" nameend="col4" align="left">1d³⁾</entry><entry namest="col5" nameend="col5" align="left">5d⁴⁾</entry><entry namest="col6" nameend="col6" align="left">5d⁵⁾</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">6 (V)</entry><entry namest="col2" nameend="col2" align="right">-</entry><entry namest="col3" nameend="col3" align="right">-</entry><entry namest="col4" nameend="col4" align="left">-</entry><entry namest="col5" nameend="col5" align="left">-</entry><entry namest="col6" nameend="col6" align="left">-</entry></row><row><entry namest="col1" nameend="col1" align="left">6</entry><entry namest="col2" nameend="col2" align="right">O</entry><entry namest="col3" nameend="col3" align="right">O</entry><entry namest="col4" nameend="col4" align="left">50 xg</entry><entry namest="col5" nameend="col5" align="left">50 x g-1</entry><entry namest="col6" nameend="col6" align="left">50 x gd</entry></row><row><entry namest="col1" nameend="col1" align="left">6a</entry><entry namest="col2" nameend="col2" align="right">O</entry><entry namest="col3" nameend="col3" align="right">O</entry><entry namest="col4" nameend="col4" align="left">100 x gd</entry><entry namest="col5" nameend="col5" align="left">50 x gd</entry><entry namest="col6" nameend="col6" align="left">50 x gd</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">6b</entry><entry namest="col2" nameend="col2" align="right">O</entry><entry namest="col3" nameend="col3" align="right">O</entry><entry namest="col4" nameend="col4" align="left">50 x gs</entry><entry namest="col5" nameend="col5" align="left">50 x gd</entry><entry namest="col6" nameend="col6" align="left">50 x gd</entry></row></tbody></tgroup><tgroup cols="6" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="26.25mm" /><colspec colnum="2" colname="col2" colwidth="26.25mm" /><colspec colnum="3" colname="col3" colwidth="26.25mm" /><colspec colnum="4" colname="col4" colwidth="26.25mm" /><colspec colnum="5" colname="col5" colwidth="26.25mm" /><colspec colnum="6" colname="col6" colwidth="26.25mm" /><tbody valign="top"><row><entry namest="col1" nameend="col6" align="justify">1) after 50,000 kinks</entry></row><row><entry namest="col1" nameend="col6" align="justify">2) after 20,000 kinks</entry></row><row><entry namest="col1" nameend="col6" align="justify">3) after 3 days of storage at RT</entry></row><row><entry namest="col1" nameend="col6" align="justify">4) after 5 days of storage at RT</entry></row><row><entry namest="col1" nameend="col6" align="justify">5) after 5 days' storage at RT and additionally 1 hour's storage at 80 ° C</entry></row></tbody></tgroup></table></tables>

The leather coated with the dispersion according to Example 6 (V) was too sticky to be tested.