Latent curing aqueous polyurethane dispersions

The present invention relates to latently crosslinking aqueous polyurethane dispersions containing<ul id="ul0001" list-style="none"><li>1. Latent crosslinking aqueous polyurethane dispersions containing<ul id="ul0002" list-style="none"><li>I) a disperse phase (PI) containing<ul id="ul0003" list-style="none"><li>Ia) a polyurethane (PUR.Ia), in addition to groups that cause the water-dispersibility of the polyurethane groups with a CC double bond in which the double bond is activated by a carbonyl group directly attached thereto, or</li><li>Ib) a mixture of<ul id="ul0004" list-style="dash"><li>a polyurethane (PUR.Ib), the groups which cause the water-dispersibility of the polyurethane, but does not support groups with a CC double bond in which the double bond is activated by a carbonyl group directly attached thereto, and</li><li>a compound (VI) other than the polyurethanes PUR.Ia and PUR.Ib which carries groups having a CC double bond in which the double bond is activated by a carbonyl group directly bonded thereto;</li></ul></li></ul></li><li>II) a compound that<ul id="ul0005" list-style="dash"><li>on average at least 2 H atoms, which are present as amino function</li><li>a water solubility of more than 1 g / l (25 ° C) and</li><li>number average molecular weight (M_n) from 200 to 1 000 000 (Compound II)</li></ul></li></ul></li></ul>

Furthermore, the invention relates to their use as a coating agent or adhesive.

Aqueous dispersions containing a polyurethane in dispersed form are well known. In order for coatings produced from the polyurethane to have particularly good mechanical properties, these dispersions are given a crosslinker component. It is particularly desirable that the crosslinking agent effects the molecular weight buildup of the polyurethane only when the polyurethane dispersion has already been converted into a film after application to the workpiece to be coated. Under these circumstances, films are obtained which have a particularly high cohesion, since then the polymer molecules of one dispersion particle can also be linked to the polymer molecules of another adjacent dispersion particle via a covalent bond.

A particularly good cohesion of the films is required, for example, in the adhesive area, especially when the adhesive bond is subjected to mechanical stress under the action of heat.

To obtain adhesive bonds that still have sufficient strength under these conditions, z. B. in EP-A-206059 recommended to add a water-emulsifiable polyisocyanate to the dispersions shortly before their processing as an adhesive crosslinker.

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

Storable, latently curing dispersions over a longer period of time, ie Such dispersions, which indeed contain the hardener, but the hardener becomes fully effective only after the processing of the dispersions, are known, for example, from EP-A-442 652. The dispersions contain, for example, a polyurethane having a carbonyl group in the aldehyde or keto function and adipic dihydrazide as the crosslinking agent. However, these dispersions require improvement in terms of strength at elevated temperature.

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

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

EP-419 945 discloses the crosslinking of water-dispersed NCO-terminated polyurethane prepolymers with pentaethylenehexamine to form urea groups.

In the non-prepublished German patent application no. 1960 86 10.8 dispersions are known which in separate phases polyurethane, the C-C 'double bonds, which are activated on carbonyl groups or mixtures of a polyurethane with another polymer carrying such groups (phase I ) and a sparingly water-soluble polyamine (phase II).

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

Accordingly, the aqueous dispersions defined above were found.

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

The phase (PI) contains preferably or consists particularly preferably of a polyurethane (PUR.Ia), composed of<ul id="ul0006" list-style="none"><li>a1) polyfunctional isocyanates having 4 to 30 carbon atoms,</li><li>a2) Polyols, of which<ul id="ul0007" 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><li>a3) monomers other than monomers (a1) and (a2) having at least one isocyanate group or at least one isocyanate group-reactive group which moreover bear at least one hydrophilic group or a potentially hydrophilic group, thereby causing the water-dispersibility of the polyurethanes,</li><li>a4) monomers other than monomers (a1), (a2) and (a3) ​​having at least one isocyanate group or at least one group reactive toward isocyanate groups, further comprising at least one group having a CC double bond in which the double bond is bonded by a directly bonded thereto Carbonyl group is activated,</li><li>a5) optionally other than the monomers (a2) to (a4) different polyvalent compounds with isocyanate-reactive groups, which are alcoholic hydroxyl groups or primary or secondary amino groups.</li></ul></li></ul>

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

Particularly noteworthy are diisocyanates X (NCO)₂where X is an aliphatic hydrocarbon radical having 4 to 12 carbon atoms, a cycloaliphatic or aromatic hydrocarbon radical having 6 to 15 carbon atoms or an araliphatic hydrocarbon radical having 7 to 15 carbon atoms. Examples of such diisocyanates are tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene 1,4-diisocyanatocyclohexane, 1-isocyanato-3,5,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), 2,2-bis- (4-isocyanatocyclohexyl) propane, trimethylhexanediisocyanate, 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 isomers and mixtures of these compounds.

Particularly suitable mixtures of these isocyanates are the mixtures of the respective structural isomers of diisocyanatotoluene and diisocyanatodiphenylmethane, in particular the mixture of 80 mol% of 2,4-diisocyanatotoluene and 20 mol% of 2,6-diisocyanatotoluene. 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 aliphatic to aromatic isocyanates 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.

Optionally, it is also possible to use those isocyanates 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 serve to introduce functional groups into the polyurethane, which are the dispersion or enable crosslinking or further polymer-analogous reaction of the polyurethane. Suitable for this purpose are monomers such as isopropenyl-α, α-dimethylbenzyl isocyanate (TMI).

To produce polyurethanes with a certain degree of branching or crosslinking, it is possible, for example, to use trivalent and tetravalent isocyanates. Such isocyanates are obtained, for example, by reacting dihydric isocyanates with one another by derivatizing part of their isocyanate groups to 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, suitable polyols (a2) are primarily relatively high molecular weight polyols (a2.1), preferably diols having a molecular weight of about 500 to 5000, preferably of about 100 to 3000 g / mol.

The diols (a2.1) are, in particular, polyesterpolyols which, for example, are from Ullmanns E ncyklopadie of industrial chemistry, 4. Edition, Volume 19, p. 62 to 65 are known. Preference is given to using polyesterpolyols which are obtained by reacting dihydric alcohols with dibasic carboxylic acids. Instead of the free polycarboxyl ic acids, it is also possible to use the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof to prepare the polyesterpolyols. The polycarboxylic acids may be aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic and optionally, for example by halogen atoms, substituted and / or unsaturated. Examples of these are: suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylenetetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, dimer fatty acids. Preference is given to 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.

As polyhydric alcohols come, for example 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-methylpropane-1,3-diol, methylpentanediols, furthermore diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol and polybutylene glycols consideration. Preferably, 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 of these are ethylene glycol, butane-1,4-diol, hexane-1,6-diol, octane-1,8-diol and dodecane-1,12-diol.

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

Also suitable are lactone-based polyesterdiols, which are homopolymers or copolymers of lactones, preferably terminal hydroxyl-containing addition products of lactones onto suitable difunctional starter molecules. Suitable lactones are preferably those which are derived from compounds of the general formula HO- (CH₂)_zDerive -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 synthesis component for the polyesterpolyols. 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, it is also possible to use the corresponding, chemically equivalent polycondensates of the hydroxycarboxylic acids corresponding to the lactones.

In addition, suitable 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 itself, for example in the presence of BF₃ or by addition of these compounds optionally in admixture 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 (4 -hydroxydiphenyl) -propane or aniline available. Particularly preferred is polytetrahydrofuran having a molecular weight of 240 to 5000, and especially 500 to 4500.

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

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

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

The proportion of the diols (a2.1), based on the total amount of the diols (a2), is preferably from 10 to 100 mol% and the proportion of the monomers (a2.2), based on the total amount of the diols (a2), is 0 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, the polyurethanes, in addition to the components (a1) and (a2), are monomers (a3) ​​other than components (a1) and (a2) having at least one isocyanate group or at least one isocyanate-reactive group and In addition, at least one hydrophilic group or a group which can be converted into hydrophilic groups carry constructed. In the following text, the term "hydrophilic groups or potentially hydrophilic groups" is abbreviated to "(potentially) hydrophilic groups". The (potentially) hydrophilic groups react much more slowly with isocyanates than the functional groups of the monomers used to build the polymer backbone.

The proportion of components with (potentially) hydrophilic groups 5 in the total amount of components (a1) to (a5) is generally such that the molar amount of the (potentially) hydrophilic groups, based on the 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 may be nonionic or, preferably, (potentially) ionic hydrophilic groups.

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

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

Ionic hydrophilic groups are especially anionic groups such as the sulfonate, the carboxylate and the phosphate group in the form of their alkali metal or ammonium salts and 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 by simple neutralization, hydrolysis or quaternization reactions into the abovementioned ionic hydrophilic groups, ie, for ex ample, carbox ylic acid groups, anhydride groups or tertiary amino groups.

(Potentially) ionic monomers (a3) ​​are described in detail, for example, in Ullmann's Encyklopadie der technischen Chemie, 4th Edition, Volume 19, pp. 311-313and, for example, in DE-A 1 495 745.

As (potentially) cationic monomers (a3), especially monomers having 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, wherein the alkyl radicals and alkanediyl units of these tertiary amines independently of each other consist of 2 to 6 carbon atoms. Furthermore, tertiary nitrogen atoms containing polyether having preferably two terminal hydroxyl groups, such as, for example by alkoxylation of two hydrogen atoms attached to amine nitrogen-bound amines, eg Methylamine, aniline, or N, N'-dimethylhydrazine, in a conventional manner are accessible, into consideration. 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, such as bromides or chlorides are converted into the ammonium salts.

Suitable 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. Preference is given to dihydroxyalkylcarboxylic acids, in particular having 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="EP0807648B1_D0001.tif" /></chemistry> in which R¹ and R² for a C₁- to C₄Alkanediyl moiety and R³ for a C₁- to C₄-Alkyl moiety, and especially dimethylolpropionic acid (DMPA) is preferred.

Also suitable are corresponding dihydroxysulfonic acids and dihydroxyphosphonic acids, such as 2,3-dihydroxypropanephosphonic acid.

Otherwise suitable are dihydroxyl compounds having 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 cyclopentanetetracarboxylic 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 also the diols (a2.1).

Suitable monomers (a3) ​​with isocyanate-reactive amino groups are aminocarboxylic acids such as lysine, β-alanine, the adducts of aliphatic diprimary diamines mentioned in DE-A 2 034 479 to α, β-unsaturated carboxylic acids such as N- (2-aminoethyl) 2-aminoethanecarboxylic acid and the corresponding N-aminoalkyl-aminoalkylcarboxylic acids, wherein the alkanediyl units consist of 2 to 6 carbon atoms, into consideration.

If monomers having potentially ionic groups are used, their conversion into the ionic form may take place 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 the counterion.

As monomers of the monomers (a2) and (a3) ​​different monomers (a4) are especially compounds having one, preferably 2 alcoholic hydroxyl groups such as (C₁- to C₆Hydroxyalkyl) acrylates, for example, hydroxyethyl acrylate and hydroxypropyl acrylate, a (C₁- to C₆Hydroxyalkyl) methacrylate, mono- or diesters of acrylic acid or methacrylic acid and trimethylolpropane or glycerol, or the bis-adduct of acrylic acid and / or methacrylic acid to a bis-epoxide 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 customary polyester polyols which are at least partially composed of maleic acid and fumaric acid. Otherwise, these polyesters have the same structure as the polyesters which are suitable as monomers (a2.2).

The monomers (a5) optionally used as synthesis components, which are different from the monomers (a2) to (a4), generally serve for crosslinking or chain extension. They are generally more than divalent non-aromatic alcohols, amines having 2 or more primary and / or secondary amino groups, and compounds which carry one or more primary and / or secondary amino groups in addition to one or more alcoholic hydroxy.

Alcohols with a value higher than 2, which can serve to set 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 isocyanate-reactive group, such as monoalcohols having one or more primary and / or secondary amino groups, for example monoethanolamine.

Polyamines having 2 or more primary and / or secondary amino groups are used especially when the chain extension or Crosslinking in the presence of water is to take place, since amines react usually faster than alcohols or water with isocyanates. This is often required when aqueous dispersions of high molecular weight crosslinked polyurethanes or polyurethanes are desired. In such cases, the procedure is to prepare prepolymers with isocyanate groups, to rapidly disperse them in water and then chain-extended or crosslinked by addition of compounds containing a plurality of isocyanate-reactive amino groups.

Amines suitable for this purpose are generally polyfunctional amines of 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 of these are diamines such as diaminoethane, diaminopropanes, diaminobutanes, diaminohexanes, piperazine, 2,5-dimethylpiperazine, amino-3-aminomethyl-3,5,5-trimethyl-cyclohexane (isophoronediamine, 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 in blocked form, eg in the form of the corresponding ketimines (see, eg CA-1 129 128), ketazines (cf. eg US-A 4,269,748) or amine salts (s. US Pat. No. 4,292,226). Oxazolidines, as used for example in US Pat. No. 4,192,937, are also blocked polyamines which can be used for the preparation of the polyurethanes according to the invention for chain extension of the prepolymers n. When using such capped polyamines they are generally mixed with the prepolymers in the absence of water and this mixture is then mixed with the dispersion water or a portion of the dispersion water, so that the corresponding polyamines are hydrolytically released.

Preference is given to using mixtures of di- and triamines, more preferably mixtures of isophoronediamine and diethylenetriamine.

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

It is advisable to use compounds having primary or secondary amino groups only in amounts such 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 do not react with the isocyanate groups to give urea but with the acryloyl or methacryloyl groups.

According to a likewise preferred embodiment, the phase (PI) contains or consists of a mixture<ul id="ul0008" list-style="dash"><li>a polyurethane (PUR.Ib) and</li><li>a polyurethane (PUR.Ic) as compound (VI),</li></ul> wherein the polyurethane (PUR.Ib) is composed of<ul id="ul0009" list-style="none"><li>b1) polyfunctional isocyanates having 4 to 30 carbon atoms,</li><li>b2) Polyols, of which<ul id="ul0010" 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 other than monomers (b1) and (b2) having at least one isocyanate group or at least one isocyanate-reactive group, which moreover bear at least one hydrophilic group or a potentially hydrophilic group, thereby causing the water-dispersibility of the polyurethanes,</li><li>b4) optionally other polyvalent compounds other than the polyols (b2) and monomers (b3) with isocyanate-reactive groups which are alcoholic hydroxyl groups or primary or secondary amino groups 5,</li></ul>    and the polyurethane (PUR.Ic) is made up of<ul id="ul0011" list-style="none"><li>c1) polyfunctional isocyanates having 4 to 30 carbon atoms,</li><li>c2) polyols, of which<ul id="ul0012" 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 the diols (c2), have a molecular weight of 60 to 500 g / mol,</li></ul></li><li>c3) monomers other than monomers (c1) and (c2) having at least one isocyanate group or at least one isocyanate-reactive group, which moreover bear at least one acryloyl or methacryloyl group.</li></ul>

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

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

Suitable monomers (c1), (c2.1), (c2.2) and (c3) are in particular the corresponding monomers which are used as monomers (a1), (a2.1), (a2.2) and (a4) are preferred.

Preferably, the monomers (c3) are 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.

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

These are preferably esters, obtainable by reaction of<ul id="ul0013" list-style="dash"><li>Polyols as described as monomers (a2.1) and (a2.2) and higher lower molecular weight alcohols such as glycerol, trimethylolpropane and pentaerythrol, these alcohols being optionally ethoxylated or propoxylated,</li><li>2- to 4-valued C₃- to C₃₆-Carboxylic acids, for example adipic acid and</li><li>Acrylic and / or methacrylic acid,</li></ul> to a carboxylic acid group-containing polyester, and subsequent esterification of the carboxylic acid groups of these esters by reaction with equivalent amounts of an epoxy compound.

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

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

In the field of polyurethane chemistry, it is well known how the molecular weight of the polyurethanes can be adjusted by selecting the proportions of the monomers reactive with one another and the arithmetic mean of the number of reactive functional groups per molecule.

Normally, the components (a1) to (a5) or (bl) to (b4) and their respective molar amounts are chosen so that the ratio A: B with<ul id="ul0014" 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</li></ul> 0.5: 1 to 2: 1, preferably 0.8: 1 to 1.5, more preferably 0.9: 1 to 1.2: 1. Most preferably, the ratio A: B is as close as possible to 1: 1.

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

The dispersions according to the invention can be prepared in a simple manner by reacting a dispersion (DI) containing, in disperse form, a polyurethane having groups with a C-C double bond in which the double bond is activated by a directly bonded carbonyl group (disperse phase PI), however, this dispersion (DI) is substantially free of polyurethanes which still carry isocyanate groups with a compound which<ul id="ul0015" list-style="dash"><li>on average at least 2, preferably 5 to 200, more preferably 10 to 100 H atoms, which are then present as the amino function</li><li>a water solubility of more than 1 g / l preferably of more than 10 g / l, more preferably of more than 100 g / l and</li><li>a number average molecular weight (M_n) of 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 (see DIN 53176).

Apart from the amino function, the compounds II generally do not bear any groups that can react with water or the polymers of phase I. Suitable compounds (II) are, in particular, poly (C 2 -C 4) -alkylene oxides which carry amino groups at the chain ends, preference being given to those which are predominantly an ethylene oxide and / or propylene oxide units.

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

These are, for example, reaction products of a diprimary polyetherdiamine and 2 moles of ethylene, propylene and / or butylene oxide per mole of polyetherdiamine, the conditions for the reaction of the polyetherdiamine with the alkylene oxide to be selected such that the N, N 'is highly selective. -Bis (hydroxyalkylamine) derivative with two secondary amino groups is formed. Examples of the polyetherdiamines are, for example 4,7-dioxadecane-1,10-diamine, 4,11-dioxatetradecane-1,14-diamine, α- (2-aminomethyl-ethyl) -ω- (2-aminomethyl-ethoxy) -polyloxy (methyl-1, 2-ethanediyl)] having a MW of 200 to 3000, and α- (3-aminopropyl) -ω- (3-aminopropoxy) -poly [oxy (1,4-butanediyl)] having a MW of 300 to 3,000.

Preferred compounds (II) are furthermore branched or unbranched polyethyleneimines and one of from 200 to 10,000. Such compounds are commercially available (Polymin® grades from BASF AG) and are described, for example, in US Pat. Nos. 3,2000,881, 3,881,069 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 of the invention in proportions such that the molar ratio of the activated by a carbonyl double bond to the hydrogen atoms of the compound (II), which is present as the amino group is 0.1: 1 to 10: 1, preferably 2: 1 to 0.5: 1.

Above all, those 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) carrying a polyurethane (PUR.Ia) having a CC double bond in which the double bond is activated by a directly attached carbonyl group, eg acryloyl or methacryloyl groups, are well known (see EP-A-443 537, 183 119, 181 486, 189 945 and 353 797).

Most often, the dispersions (DI) are prepared by one of the following methods:

According to the "acetone process", a water-dispersible polyurethane is prepared from the components (a1) to (a5) or (b1) to (b4) in a water-miscible solvent boiling below 100 ° C. under normal pressure. Add enough water to form a dispersion 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 bearing isocyanate groups. The components (a1) to (a5) or (b1) to (b4) are chosen here such that the ratio A: B as defined is greater than 1.0 to 3, preferably 1.05 to 1.5. The prepolymer is first dispersed in water and then chain-extended, optionally by reaction of the isocyanate groups with amines which carry more than 2 isocyanate-reactive amino groups, or carrying the 2 isocyanate-reactive amino groups with amines. Chain extension also occurs 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 of the monomers (b1) to (b4), the stoichiometric ratio of the starting materials and the reaction time is preferably selected so that the prepolymer before its dispersion has a content of less than 0.1 wt .-% NCO groups per kg Contains prepolymer. It is assumed that the weight of the NCO groups is 42 g per mole.

The polyaddition of the 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 atmospheric pressure or under autogenous pressure.

The required reaction 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 affected by a variety of parameters such as temperature, concentration of monomers, reactivity of the monomers.

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

Rührkessel come into consideration as polymerization, especially when provided by the concomitant use of solvents for a low viscosity and good heat dissipation.

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

The dispersions (DI), which contain as disperse phase (PI) a mixture of the polyurethane (PUR.Ib) and the compound (VI), are conveniently prepared by the not yet dispersed polyurethane (PUR.Ib) and in the acetone process 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) coexist, ie both together in one particle.

This method of codispersing 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 aids such as phenol condensation resins of aldehydes and phenol or phenol derivatives or epoxy resins.

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

These hydrophobic adjuvants may also be contained in the disperse phase (PI).

The dispersions (DI) generally have a solids content of 10 to 75, preferably from 20 to 65 wt .-% 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 may contain other water-emulsifiable or dispersible resins, such as polymer, polyurethanes, polyester, epoxy or alkyd resins, as well as commercial 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 bonding or coating of 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 according to the generally customary in the adhesive, leather or paint industry, ie by spraying the dispersions on the substrate sprayed or doctored and then dried.

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

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

The adhesive compounds produced by these methods are characterized in particular by the fact that they are storage stable and can be produced with you bonds with a high heat resistance.

Used as a leather coating, they give the leather a surface that gives a pleasant leather-typical feel on contact with the skin, a high mechanical resistance and good processing properties, eg when ironing the coated leather.

Preparation Examples:

The viscosities of the dispersions were measured at a temperature of 20 ° C. and a shear rate of 250 s -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 by turbidity measurements. For this purpose, the turbidity of a dispersion having a solids content of 0.01 wt .-% was relative to dist. Water at a thickness of 2.5 cm and determined at room temperature.<maths id="math0001" num=""><math display="block"><mrow><mtext>LD = </mtext><mfrac><mrow><msub><mrow><mtext>intensity</mtext></mrow><mrow><mtext>Disp</mtext></mrow></msub><mtext>100</mtext></mrow><mrow><msub><mrow><mtext>intensity</mtext></mrow><mrow><mtext>water</mtext></mrow></msub></mrow></mfrac></mrow></math><img file="EP0807648B1_D0002.tif" /></maths>

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

The symbols used in the following examples have the meanings given below:<dl id="dl0001" compact="compact"><dt>OHZ =</dt><dd>hydroxyl</dd><dt>TDI =</dt><dd>toluene diisocyanate</dd><dt>HDI =</dt><dd>hexamethylene diisocyanate</dd><dt>PUD salt logo CNRS logo INIST</dt><dd>Na salt of the Michael adduct of acrylic acid and ethylenediamine</dd><dt>DBTL =</dt><dd>dibutyltindilaurate</dd><dt>DMPA =</dt><dd>dimethylolpropionic</dd><dt>RE 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 of adipic acid and butanediol (OH number = 45) were reacted with 0.05 g of DBTL in 152.2 g of acetone at 65 ° C. with 29.6 g of TDI for 1 h. 28.6 g of HDI are metered in and kept at 65 ° C. for a further 37 minutes. 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 homogeneously stirred into 160 g of acetone. Thereafter, it was dispersed with 1200 g of deionized water. After addition of 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"><dt>Analysis:</dt><dd>Solids content: 40% LD: 51.8% Viscosity: 26.4 mPas pH: 8.81 Double bond content: 0.83 mol / kg</dd></dl>

example 1

A portion of the dispersion was treated 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. LD: 62 Vis .: 34.1 mPas pH: 9.3 The dispersion was filmed at 40 ° C: K value: undissolved

Example 2 (V) (for comparison)

595.9 g of a polyester of adipic acid and diethylene glycol (OHN = 42) were reacted with 0.1 g of DBTL, 50.2 g of 1,4-butanediol and 80.1 g of TDI at 65 ° C. for 1 h in 172 g of acetone. Then, 77.4 g HDI was metered in and stirred at 65 ° C for 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 PUD salt is stirred for a few minutes and a solution of 80 g of an adduct of 2 moles of acrylic acid to 1 mole of bisphenol A bisglycidylether stirred in 80 g of acetone homogeneously. Then was dispersed with 1200 g of deionized water. The acetone was distilled off in vacuo at temperatures up to 40 ° C and the dispersion adjusted to 40% solids content.<dl id="dl0003"><dt>Analysis:</dt><dd>Solids content: 40% LD: 87.2% Viscous: 121 mPas pH: 8 K value: 85 Double bond content: 0.41 mol / kg</dd></dl>

Example 2

A portion 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 of adipic acid and butanediol (OHN = 45) was reacted with 0.03 g of DBTL and 31.5 g of TDI in 171.7 g of acetone for 1 h at 65 ° C. Then, 30.4 g HDI were added and held 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% It was chain-extended with 40.95 g of PUD salt and diluted after a few minutes with 300 g of deionized 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. It was then dispersed with 900 g of deionized water. The acetone is distilled off in vacuo at temperatures up to 40 ° C and the solids content adjusted to 40%.<dl id="dl0004"><dt>Analysis:</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

A portion of the dispersion was treated with an equivalent amount of amine in the form of a polyethyleneimine Pn = 20 as a 25% solution. K value: 55

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

Example 4 (V) (for comparison)

585.3 g of a polyester of adipic acid and diethylene glycol (OHN = 42) were mixed with 0.5 g of DBTL, 21.45 g of DMPA, 72.3 g of an adduct of 2 mol of acrylic acid to 1 mol of butanediol bisglycidyl ether (M = 330 g / mol) and 0.05 g of dimethylhydroquinone in 195.5 g Acetone submitted at 40 ° C. 120.9 g of TDI are metered in and reacted at 70 ° C. for 277 minutes. Then it is 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 deionized water. The acetone is distilled off in vacuo at temperatures up to 40 ° C and the solids content adjusted to 40%.<dl id="dl0005"><dt>Analysis:</dt><dd>Solids content: 40% LD: 73 Viscosity: 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 treated with a polyethyleneimine Pn = 20 as a 25% solution. Molar ratio double bonds: amino groups 2: 1. K value: 43

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

Example 5 (V) (for comparison)

465.2 g of polypropylene oxide diol (OH number = 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 at 110 ° C. for 122 min. It 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 deionized water and 160 g of an adduct of 2 moles of acrylic acid to 1 mole of bisphenol A bisglycidylether (M = 484) stirred in 160 g of acetone homogeneously. Then was dispersed with 1200 g of deionized water. The acetone was distilled off in vacuo at temperatures up to 40 ° C and the solids content adjusted to 40%.<dl id="dl0006"><dt>Analysis:</dt><dd>Solids content: 40% LD: 97 Viscosity: 417 mPas pH: 8.1 K value: 43 Double bond content: 0.83 mol / kg</dd></dl>

Example 5

A portion of the dispersion was treated with a 25% solution of a polyethyleneimine Pn = 20. There were equimolar amounts of amine and double bonds. K value: 47

Example 6 (V) (for comparison)

400 g (0.2 mol) of a polyesterol of adipic acid, neopentyl glycol and hexane diol of OH number 56, 21.4 g (0.16 mol) of dimethylolpropionic acid and 14.3 g (0.106 mol) of trimethylolpropane were mixed. To this was added 127.2 g (0.73 mol) of tolylene diisocyanate and reacted at 100 ° C for 90 min. It 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 was diluted with 500 g of acetone. The NCO content is 0.32 wt .-% (calc. 0.38%). Then, 15.1 g (0.15 mol) of triethylamine was mixed and dispersed by adding 1200 g of water. Subsequently, the acetone was iV distilled off. A finely divided dispersion having a solids content of 34.0% and a content of double bonds (DB) of 177 mmol / kg of dispersion was obtained.

Example 6

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

Example 6a

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

Example 6b

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

A Application testing as an adhesive

The dispersions are thickened with 2% Collacral VL and knife-coated 2 mm thick on 5 hardboard boards (20 cm × 3 cm) and dried at RT for 60 minutes or 60 ° C. for 3 minutes. Then, an ASA film or PVC film with 0.5 N / mm2 for 30 s at 80 ° C is pressed.

It is determined by the peel strength, the heat resistance. After 24 hours, the heat resistance test (WSF) is tested. For this purpose, the ASA film or PVC film is loaded in a peel angle of 180 ° C with a weight of 300 g. The temperature is raised by 10 ° C every 30 minutes. As heat resistance, the highest temperature is given, at which the drainage distance is just smaller than 50 mm.

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="left">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">2 (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 at 60 ° C for 3 min</entry></row></tbody></tgroup></table></tables>

B. Application testing as leather coating

The dispersions listed in Table 2 were applied as a finish to primed cowhide leather.

The flex fatigue test was carried out in accordance with DIN 53 351 / IuP (method of physical leather testing by the International Union of Leather Chemists, Federations) with the Bally Flexometer).

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

The assessment was made according to the extent of damage O no, g small, 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="left">Examples</entry><entry namest="col2" nameend="col2" align="left">Flex.</entry><entry namest="col3" nameend="col3" align="left">Flex.</entry><entry namest="col4" nameend="col6" align="left">wet abrasion</entry></row><row><entry namest="col1" nameend="col1" /><entry namest="col2" nameend="col2" align="left">dry¹⁾</entry><entry namest="col3" nameend="col3" align="left">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="left">-</entry><entry namest="col3" nameend="col3" align="left">-</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="left">O</entry><entry namest="col3" nameend="col3" align="left">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="left">O</entry><entry namest="col3" nameend="col3" align="left">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="left">O</entry><entry namest="col3" nameend="col3" align="left">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 buckling</entry></row><row><entry namest="col1" nameend="col6" align="justify">2) after 20 000 buckling</entry></row><row><entry namest="col1" nameend="col6" align="justify">3) after 3 days storage at RT</entry></row><row><entry namest="col1" nameend="col6" align="justify">4) after 5 days storage at RT</entry></row><row><entry namest="col1" nameend="col6" align="justify">5) after 5 days storage at RT and additionally 1 hour storage at 80 ° C</entry></row></tbody></tgroup></table></tables>

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