EP2016145A1 - Microporous coating based on polyurethane-polyurea - Google Patents

Abstract

The invention relates to new microporous coatings based on polyurethane-polyurea and also to a process for producing microporous coatings.

Description

Microporous coating based on polyurethane polvurea

The invention relates to novel microporous coatings and to a process for producing microporous coatings.

In the field of textile coating, polyurethanes have traditionally played an important role in their various application forms - solution, high solids, aqueous dispersions.

The trend, especially in the field of coatings, has been moving steadily away from solvent systems to high solids and, in particular, to aqueous systems for years due to the ecological advantages.

The situation is still slightly different with polyurethane artificial leathers. These micro-porous coatings are still produced according to the current state of the art, mostly after the so-called bath coagulation process.

In the process of bath coagulation, which is primarily used today, textiles are coated or impregnated with polyurethanes dissolved in organic solvents (for example dimethylformamide). The coagulation takes place immediately afterwards by immersion in a water bath. The resulting coatings are characterized by their softness and good water vapor permeability. The method is bound to the use of this solvent because of the specific properties of the organic solvent (dissolving power, miscibility with water, etc.).

Disadvantages of this method consist in particular in the necessary and expensive measures for safe handling, for the treatment and recycling of very large amounts of solvent.

In alternative methods such as evaporation coagulation, which is based on the use of a volatile solvent and a less volatile non-solvent for the binder, the solvent escapes initially with gentle heating, so that the binder coagulates by the steadily increasing proportion of non-solvent; In addition to the equally necessary use of large amounts of solvent, the disadvantage is the enormous technical effort required and the optimization possibilities which are very limited by the process parameters.

The salt, acid or electrolyte coagulation also used is carried out by dipping the coated substrate or, as in the case of gloves, the first in the

Dispersion immersed form, in a concentrated salt solution or acid-added

Water o. Ä., The binder coagulated by the high electrolyte content. disadvantage This method consists in the complicated technical implementation and especially in the high amount of polluted wastewater.

The prepolymer method, according to which a substrate coated with isocyanate prepolymer is immersed in water and then a polyurea in a porous structure is obtained with CO ₂ elimination, proves to be disadvantageous, inter alia due to the very high reactivity of the formulations and the associated short processing times.

The heat-sensitive non-postcrosslinkable binder possible coagulation by increasing the temperature often leads to unacceptable coating results.

DE-A 19 856 412 describes a process for aqueous coagulation based on postcrosslinkable aqueous polyurethane dispersions, which has no or only a small amount

Content of organic solvent and without use of salt, acid or the like Elektroyt- baths and overall represents a simple process. The method described is particularly suitable for coating non-microporous Kompaktfihnen in a small layer thickness.

DE-A 10300478 describes a priority post-crosslinkable on aqueous polyurethane dispersions in DE-A 19,856,412 based method by which this foamed be applied to a textile substrate and there by special coagulants thermally at temperatures of 100 ⁰ C to 110 ⁰ C are coagulated and used for the production of compact coatings, which are used for example as printed synthetic suede in the automobile, on furniture or in the clothing sector uses.

The production of microporous coatings with high layer coverage by aqueous coagulation has not yet been satisfactorily solved according to the current state of the art on the basis of the ecologically harmless aqueous polyurethane-polyurea dispersions (PU dispersions) and is therefore an object of the present invention.

It has now surprisingly been found that it is possible to obtain spreadable pastes having advantageous properties using special anionically hydrophilized PU dispersions (I) in combination with cationically hydrophilized polyurethane-polyurea dispersion as cationic coagulants (H).

It has also been found that microporous coatings with high layer coverage can be produced by a novel process comprising the following process steps: A. Preparation of a spreadable coating composition (1) comprising an aqueous anionically hydrophilized polyurethane-polyurea dispersion (I) and a cationically hydrophilicized polyurethane-polyurea dispersion as a cationic coagulant (II)

B. foaming of (1) with simultaneous at least partial coagulation of

Foam at low temperature

C. Application of the foamed and at least partially coagulated composition (1) to a textile support

D. drying and optionally

E. Fixation of the foam matrix by a further drying step at higher

temperature

The present invention also provides a process for the preparation of the spreadable coating composition (1), characterized in that it comprises the components selected from the group of

I.) aqueous anionic hydrophilic polyurethane dispersions whose content of

COCT or -SO ₃ ^" or -PO ₃ ^2" groups is between 0.1 to 15 milliequivalents per 100 g of solid resin,

π.) cationically hydrophilized polyurethane-polyurea dispersions as cationic coagulants,

HI.) Foaming agent,

IV.) Crosslinker

such as

V.) optionally thickener

contains and these are mixed together homogeneously in any order prior to step B.) by known mixing methods.

The aqueous, anionically hydrophilicized polyurethane dispersions (I) present in the compositions essential to the invention can be obtained by:

A) isocyanate-functional prepolymers Al) organic polyisocyanates

A2) polymeric polyols having number average molecular weights of 400 to

8000 g / mol, preferably 400 to 6000 g / mol and more preferably from 600 to 3000 g / mol, and OH functionalities from 1.5 to 6, preferably 1.8 to 3, particularly preferably from 1.9 to 2, 1, and

A3) optionally hydroxy-functional compounds having molecular weights of 32 to 400 g / mol and

A4) optionally isocyanate-reactive, anionic or potentially anionic and / or optionally nonionic hydrophilicizing agents,

getting produced,

B) whose free NCO groups then wholly or partly

Bl) optionally with amino-functional compounds having molecular weights of 32 to 400 g / mol and / or

B2) isocyanate-reactive, preferably amino-functional, anionic or potentially anionic hydrophilicizing agents

are reacted under chain extension and the resulting prepolymers before, during or after step B) are dispersed in water, optionally containing, potentially ionic groups are converted by partial or complete reaction with a neutralization agent in the ionic form.

In order to achieve an anionic hydrophilization, hydrophilicizing agents must be used in A4) and / or B2) which have at least one group which is reactive toward NCO groups, such as amino, hydroxy or thiol groups, and furthermore -COO ^" or -SO ₃ ^" or -PO ₃ ^{2 "} as anionic or their fully or partially protonated acid forms as potentially anionic groups.

Preferred aqueous anionic polyurethane dispersions (I) have a low level of hydrophilic anionic groups, preferably from 0.1 to 15 milliequivalents per 100 g of solid resin. In order to achieve a good sedimentation stability, the number average particle size of the polyurethane dispersions I.) is preferably less than 750 nm, more preferably less than 500 nm and most preferably less than 400 nm, determined by means of laser correlation spectroscopy.

The ratio of NCO groups of the compounds of component A1) to NCO-reactive groups such as amino, hydroxy or thiol groups of the compounds of components A2) to A4) is 1.05 to 3.5 in the preparation of the NCO-functional prepolymer , preferably 1.2 to 3.0, more preferably 1.3 to 2.5.

The amino-functional compounds in stage B) are used in such an amount that the equivalent ratio of isocyanate-reactive amino groups of these compounds to the free isocyanate groups of the prepolymer is 40 to 150%, preferably between 50 and 125%, particularly preferably between 60 and 120%.

Suitable polyisocyanates of component A1) are the aromatic, araliphatic, aliphatic or cycloaliphatic polyisocyanates known per se to one skilled in the art

NCO functionality of 2.

Examples of such suitable polyisocyanates are 1, 4-butylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,2,4 and / or 2,4,4-trimethyl hexamethylene diisocyanate, the isomeric bis (4 , 4'-isocyanatocyclohexyl) methanes or mixtures thereof of any isomer content, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and / or 2,6-toluene diisocyanate, 1,5-naphthylene diisocyanate, 2,2 ' and / or 2,4'- and / or 4,4'-diphenylmethane diisocyanate, 1,3- and / or 1,4-bis (2-isocyanato-prop-2-yl) -benzene (TMXDI), 1 , 3-bis (isocyanatomethyl) benzene (XDI), as well as alkyl-2,6-diiso- cyanatohexanoate (lysine diisocyanates) with Cl-C8-alkyl groups.

In addition to the abovementioned polyisocyanates, it is also possible proportionally to use modified diisocyanates having uretdione, isocyanurate, urethane, allophanate, biuret, iminooxadiazinedione and / or oxadiazinetrione structures and unmodified polyisocyanate having more than 2 NCO groups per molecule, e.g. 4-isocyanatomethyl-l, 8-octane diisocyanate (nonantriisocyanate) or triphenylmethane-4,4 ', 4 "-triisocyanat be used with.

Preference is given to polyisocyanates or polyisocyanate mixtures of the abovementioned type with exclusively aliphatic and / or cycloaliphatic bonded isocyanates. natgruppen and an average NCO functionality of the mixture of 2 to 4, preferably 2 to 2.6 and particularly preferably 2 to 2.4.

Particularly preferred in Al) are 1,6-hexamethylene diisocyanate, isophorone diisocyanate, the isomeric bis (4,4'-isocyanatocyclohexyl) methanes, and mixtures thereof.

In A2) are used polymeric polyols having a number average molecular weight M _n of 400 to 8000 g / mol, preferably from 400 to 6000 g / mol and particularly preferably from 600 to 3000 g / mol. These preferably have an OH functionality of from 1.5 to 6, particularly preferably from 1.8 to 3, very particularly preferably from 1.9 to 2.1.

Such polymeric polyols are the polyester polyols known per se in polyurethane coating technology, polyacrylate polyols, polyurethane polyols, polycarbonate polyols, polyether polyols, polyester polyacrylate polyols, polyurethane polyacrylate polyols, polyurethane polyester polyols, polyurethane polyether polyols, polyurethane polycarbonate polyols and polyester polycarbonate polyols. These can be used in A2) individually or in any mixtures with each other.

Such polyester polyols are the known polycondensates of di- and optionally tri- and tetraols and di- and optionally tri- and tetracarboxylic acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols for the preparation of the polyesters.

Examples of suitable diols are ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyalkylene glycols such as polyethylene glycol, furthermore 1,2-propanediol, 1,3-propanediol, butanediol (1,3), butanediol (1,4), hexanediol ( l, 6) and isomers, neopentyl glycol or hydroxypivalic acid neopentyl glycol esters, with hexanediol (1,6) and isomers, neopentyl glycol and neopentyl glycol hydroxypivalate being preferred. In addition, it is also possible to use polyols, such as trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethyl isocyanurate.

Suitable dicarboxylic acids are phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, tetrachlorophthalic acid, maleic acid, fumaric acid, itaconic acid, malonic acid, suberic acid, 2-methylsuccinic acid, 3,3-diethylglutaric acid and / or 2,2-dimethylsuccinic acid. The acid source used may also be the corresponding anhydrides. If the mean functionality of the polyol to be esterified is greater than 2, monocarboxylic acids, such as benzoic acid and hexanecarboxylic acid may additionally be used.

Preferred acids are aliphatic or aromatic acids of the abovementioned type. Particular preference is given to adipic acid, isophthalic acid and, if appropriate, trimellitic acid.

Hydroxycarboxylic acids which can be used as reactants in the preparation of a hydroxyl-terminated polyester polyol include hydroxycaproic acid, hydroxybutyric acid, hydroxydecanoic acid, hydroxystearic acid and the like. Suitable lactones are caprolactone, butyrolactone and homologs. Preference is given to caprolactone.

It is likewise possible in A2) to use hydroxyl-containing polycarbonates, preferably polycarbonatediols, having number-average molecular weights M _{n of} from 400 to 8000 g / mol, preferably from 600 to 3000 g / mol. These are obtainable by reaction of carbonic acid derivatives, such as diphenyl carbonate, dimethyl carbonate or phosgene, with polyols, preferably diols.

Examples of such diols are ethylene glycol, 1,2- and 1,3-propanediol, 1,3- and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 1,4-bis-hydroxymethylcyclohexane, 2-Methyl-l, 3-propanediol, 2,2,4-Trimethylpentandiol-l, 3, dipropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols, bisphenol A and lactone-modified diols of the type mentioned above.

The polycarbonate diol preferably contains from 40 to 100% by weight of hexanediol, preferably 1,6-hexanediol and / or hexanediol derivatives. Such hexanediol derivatives are based on hexanediol and have ester or ether groups in addition to terminal OH groups. Such derivatives are obtainable by reaction of hexanediol with excess caprolactone or by etherification of hexanediol with itself to give di- or trihexylenglycol.

Instead of or in addition to pure polycarbonate diols, it is also possible to use polyether-polycarbonate diols in A2).

The hydroxyl-containing polycarbonates are preferably built linear.

Likewise, in A2) polyether polyols can be used. Suitable examples are the polytetra methylene glycol polyethers known per se in polyurethane chemistry, such as are obtainable by polymerization of tetrahydrofuran by means of cationic ring opening.

Also suitable polyether polyols are the per se known addition products of styrene oxide, ethylene oxide, propylene oxide, butylene oxides and / or epichlorohydrin to di- or polyfunctional starter molecules. Polyether polyols, based on the at least proportional addition of ethylene oxide to di- or polyfunctional starter molecules, can also be used as component A4) (nonionic hydrophilicizing agents).

As suitable starter molecules, it is possible to use all known compounds according to the prior art, such as, for example, water, butyldiglycol, glycerol, diethylene glycol, trimethylolpropane, propylene glycol, sorbitol, ethylenediamine, triethanolamine, 1,4-butanediol. Preferred starter molecules are water, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol and butyl diglycol.

Particularly preferred embodiments of the polyurethane dispersions (I) comprise, as component A2), a mixture of polycarbonate polyols and polytetramethylene glycol polyols, the proportion of polycarbonate polyols in the mixture being from 20 to 80% by weight and the proportion of polytetramethylene glycol polyols from 80 to 20% by weight in this mixture .-% is. Preference is given to a proportion of 30 to 75 wt .-% of polytetramethylene glycol polyols and a content of 25 to 70 wt .-% of polycarbonate polyols. Particularly preferred is a proportion of 35 to 70 wt .-% of polytetramethylene glycol polyols and a proportion of 30 to

65 wt .-% of polycarbonate polyols, each with the proviso that the sum of the weight percent of polycarbonate and Polytetramethylenglykolpolyole 100% and the proportion of the sum of the polycarbonate and Polytetramethylenglykolpolyetherpolyole to the component A2) at least 50 wt .-%, preferably 60 wt .-% and particularly preferably at least 70 wt .-% is.

The compounds of component A3) have molecular weights of 62 and 400 g / mol.

In A3), polyols of the stated molecular weight range having up to 20 carbon atoms, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butylene glycol, cyclohexanediol, 1,4 Cyclohexanedimethanol, 1,6-hexanediol, neopentyl glycol, hydroquinone dihydroxyethyl ether, bisphenol A (2,2-bis (4-hydroxyphenyl) propane), hydrogenated bisphenol A, (2,2-bis (4-hydroxycyclohexyl) propane), Trimethylolpropane, glycerol, pentaerythritol and any mixtures thereof are used with each other.

Also suitable are ester diols of the stated molecular weight range, such as α-hydroxybutyl-ε-hydroxycaproic acid ester, ω-hydroxyhexyl-γ-hydroxybutyric acid ester, adipic acid (β-hydroxyethyl) ester or terephthalic acid bis (β-hydroxyethyl) ester.

Furthermore, it is also possible to use monofunctional, isocyanate-reactive, hydroxyl-group-containing compounds in A3). Examples of such monofunctional compounds are ethanol, n-butanol, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, ethyl glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, 2-ethylhexanol, 1-octanol, 1 -Dodecanol, 1-hexadecanol.

Preferred compounds of component A3) are 1,6-hexanediol. 1,4-butanediol, neopentyl glycol and trimethylolpropane.

Under anionic or potentially anionic hydrophilic compounds of the component

A4), all compounds are understood which have at least one isocyanate-reactive group such as a hydroxyl group and at least one functionality such as - COO-M ⁺ , -SO ₃ TVT ₅ -PO (OM ⁺ ) _Z with M ^+, for example, metal cation, H ⁺ , NH ₄ ⁺ , NHR ₃ ⁺ , where R may each be a C _r Ci ₂ -alkyl radical, C ₅ -C ₆ -cycloalkyl radical and / or a C ₂ -C ₄ -hydroxyalkyl radical which, upon interaction with aqueous media, has a pH-dependent Dissociation equilibrium is received and can be charged in this way negative or neutral. Suitable anionic or potentially anionic hydrophilizing compounds are mono- and dihydroxycarboxylic acids, mono- and dihydroxysulfonic acids, as well as mono- and dihydroxyphosphonic acids and their salts. Examples of such anionic or potentially anionic hydrophilicizing agents are dimethylolpropionic acid, dimethylolbutyric acid, hydroxypivalic acid, malic acid, citric acid, glycolic acid, lactic acid and the propoxylated adduct of 2-butenediol and NaHSO ₃ , as described in DE-A 2 446 440, page 5-9 , Formula I-III is described. Preferred anionic or potentially anionic hydrophilicizing agents of component A4) are those of the abovementioned type which have carboxylate or carboxylic acid groups and / or sulfonate groups.

Particularly preferred anionic or potentially anionic hydrophilicizing agents A4) are those which contain carboxylate or carboxylic acid groups as ionic or potentially ionic Groups contain, such as dimethylolpropionic acid, Dimethylolbuttersäue and Hydroxypiva- linsäure or their salts.

Suitable nonionically hydrophilicizing compounds of component A4) are e.g. Polyoxyalkylenether containing at least one hydroxy or amino group, preferably at least one hydroxy group.

Examples are the monohydroxy-functional, on average 5 to 70, preferably 7 to 55 ethylene oxide units per molecule having Polyalkylenoxidpolyetheralkohole, as they are accessible in a conventional manner by alkoxylation of suitable starter molecules (eg in Ullmann's Encyclopaedia of Industrial Chemistry, 4th Edition, Volume 19 , Verlag Chemie, Weinheim pp. 31-38).

These are either pure polyethylene oxide ethers or mixed polyalkylene oxide ethers, wherein they contain at least 30 mol%, preferably at least 40 mol% based on all alkylene oxide units contained in ethylene oxide units.

Particularly preferred nonionic compounds are monofunctional mixed polyalkylene oxide polyethers which have 40 to 100 mol% of ethylene oxide and 0 to 60 mol% of propylene oxide units.

Suitable starter molecules for such nonionic hydrophilicizing agents are saturated monoalcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, the isomers pentanols, hexanols, octanols and nonanols, n-decanol, n-dodecanol, n-tetradecanol, n-hexadecanol, n-octadecanol, cyclohexanol, the isomeric methylcyclohexanols or hydroxymethylcyclohexane, 3-ethyl-3-hydroxymethyloxetane or tetrahydrofurfuryl alcohol, diethylene glycol monoalkyl ethers such as diethylene glycol monobutyl ether, unsaturated alcohols such as allyl alcohol, 1,1 Dimethylalcohol or oleic alcohol, aromatic alcohols such as phenol, the isomeric cresols or methoxyphenols, araliphatic alcohols such as benzyl alcohol, anisalcohol or cinnamyl alcohol, secondary

Monoamines such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, bis (2-ethylhexyl) amine, N-methyl and N-ethylcyclohexylamine or dicyclohexylamine and heterocyclic secondary amines such as morpholine, pyrrolidine, piperidine or IH-pyrazole. Preferred starter molecules are saturated monoalcohols of the type mentioned above. Particular preference is given to diethylene glycol monobutyl ether or n-butanol as

Starter molecules used. Alkylene oxides which are suitable for the alkoxylation reaction are, in particular, ethylene oxide and propylene oxide, which can be used in any desired order or even as a mixture in the alkoxylation reaction.

As component Bl) can di- or polyamines such as 1,2-ethylenediamine, 1,2- and 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, isophoronediamine, isomer mixture of 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylenetriamine, triaminononane, 1,3- and 1,4-xylylenediamine, α, α, α ', α'-tetramethyl-1, 3- and -1,4 -xylylenediamine and 4,4-diaminodicyclohexylmethane and / or dimethylethylenediamine be used. Also possible is the use of hydrazine or hydrazides such as adipic dihydrazide. Isophoronediamine, 1,2-ethylenediamine, 1,4-diaminobutane, hydrazine and diethylenetriamine are preferred.

In addition, as component Bl), compounds which, in addition to a primary amino group, also have secondary amino groups or, in addition to an amino group (primary or secondary), also OH groups, can be used. Examples of these are primary / secondary amines, such as diethanolamine, 3-amino-1-methylaminopropane, 3-amino-1-ethylaminopropane, 3-amino-1-cyclohexylaminopropane, 3-amino-1-methylaminobutane, alkanolamines such as N-aminoethylethanolamine, ethanolamine, 3-aminopropanol, neopentanolamine.

Furthermore, as component Bl) it is also possible to use monofunctional isocyanate-reactive amine compounds, for example methylamine, ethylamine, propylamine, butylamine, octylamine, laurylamine, stearylamine, isononyloxypropylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, N-methylaminopropylamine, diethyl (methyl) amino-propylamine, morpholine, piperidine, or suitable substituted derivatives thereof, amide amines from diprimary amines and monocarboxylic acids, monoketime of diprimary amines, primary / tertiary amines, such as N, N-dimethylaminopropylamine.

Preferred compounds of component Bl) are hydrazine, 1,2-ethylenediamine, 1,4-

Diaminobutane and isophoronediamine.

Under anionic or potentially anionic hydrophilic compounds of component B2) are understood to mean all compounds which have at least one isocyanate-reactive group, preferably an amino group, and at least one functionality such as -COO-M ⁺ , -SO ₃ TVT ⁺ , -PO (OTVf) ₂ with M ^+, for example, the same metal cation, H ⁺ ,

NH ₄ ^+, NHR, where R ₅ -C ₆ cycloalkyl radical and / or a C _{2 3} ⁺ C _r each represents a Ci ₂ alkyl group, C - Cj-hydroxyalkyl group may be, which on interaction with aqueous media, a pH Value-dependent dissociation equilibrium is received and can be loaded in this way negative or neutral.

Suitable anionic or potentially anionic hydrophilizing compounds are mono- and diaminocarboxylic acids, mono- and diaminosulfonic acids, and mono- and diaminophosphonic acids and their salts. Examples of such anionic or potentially anionic

Hydrophilicizing agents are N- (2-aminoethyl) -β-alanine, 2- (2-aminoethylamino) ethanesulfonic acid, ethylenediamine-propyl- or -butylsulfonic acid, 1,2- or 1,3-propylenediamine-β-ethylsulfonic acid , Glycine, alanine, taurine, lysine, 3,5-diaminobenzoic acid and the addition product of IPDA and acrylic acid (EP-A 0 916 647, Example 1). Furthermore, the cyclohexylaminopropanesulfonic acid (CAPS) known from WO-A 01/88006 can be used as anionic or potentially anionic hydrophilicizing agent.

Preferred anionic or potentially anionic hydrophilicizing agents of component B2) are those of the abovementioned type which have carboxylate or caroboic acid groups and / or sulfonate groups such as the salts of N- (2-aminoethyl) -β-alanine, the 2- (2-aminoethylamino) ethanesulfonic acid or the addition product of IPDA and

Acrylic acid (EP-A 0 916 647, Example 1).

For hydrophilization it is also possible to use mixtures of anionic or potentially anionic hydrophilicizing agents and nonionic hydrophilicizing agents.

In a preferred embodiment for the preparation of the special polyurethane dispersions, the components Al) to A4) and Bl) to B2) are used in the following amounts, the Einzehnengen always add up to 100 wt .-%:

From 5 to 40% by weight of component Al),

55 to 90% by weight A2),

0.5 to 20% by weight of the sum of components A3) and Bl)

0.1 to 25 wt .-% sum of the components component A4) and B2), wherein based on the total amounts of the components Al) to A4) and Bl) to B2) 0.1 to 5 wt .-% of anionic or potentially anionic hydrophilicizing agents from A4) and / or B2) can be used. In a particularly preferred embodiment for the preparation of the specific polyurethane dispersions, the components A1) to A4) and B1) to B2) are used in the following amounts, the individual amounts always adding up to 100% by weight:

From 5 to 35% by weight of component Al),

60 to 90% by weight A2),

0.5 to 15 wt .-% sum of the components A3) and Bl)

0.1 to 15 wt .-% sum of the components component A4) and B2), wherein based on the total amounts of the components Al) to A4) and Bl) to B2) 0.2 to 4 wt .-% of anionic or potentially anionic hydrophilicizing agents from A4) and / or B2) can be used.

In a very particularly preferred embodiment for the preparation of the specific polyurethane dispersions, the components A1) to A4) and B1) to B2) are used in the following amounts, the individual amounts always adding up to 100% by weight:

From 10 to 30% by weight of component Al),

65 to 85% by weight A2),

0.5 to 14 wt .-% sum of the components A3) and Bl)

0.1 to 13.5 wt .-% sum of the components A4) and B2), wherein based on the total amounts of the components Al) to A4) and Bl) to B2) 0.5 to 3.0 wt .-% of anionic or potentially anionic hydrophilicizing agents from A4) and / or B2) can be used.

The preparation of the anionically hydrophilicized polyurethane dispersions (I) can be carried out in one or more stages An in homogeneous or in multistage reaction, partly in disperse phase. After complete or partial polyaddition from Al) to A4), a dispersing, emulsifying or dissolving step takes place. This is followed, if appropriate, by a further polyaddition or modification in disperse phase.

In this case, all known from the prior art methods such. Example, prepolymer mixing method, acetone method or Schmelzdispergierverfahren can be used. Preferably, the acetone method is used. For the preparation by the acetone process, the constituents A2) to A4) and the polyisocyanate component Al) are usually completely or partially initially charged for preparation of an isocyanate-functional polyurethane prepolymer and optionally diluted with a water-miscible but isocyanate-inert solvent and cooled to temperatures in the Range of 50 to 120 ° C heated. To accelerate the Isocyanatadditionsreaktion known in polyurethane chemistry catalysts can be used.

Suitable solvents are the customary aliphatic, ketofunctional solvents, such as acetone, 2-butanone, which can also be added later, not only at the beginning of the preparation but, if appropriate, in parts. Preference is given to acetone and 2-butanone.

Other solvents such as xylene, toluene, cyclohexane, butyl acetate, methoxypropyl acetate, N-methylpyrrolidone, N-ethylpyrrolidone, solvents with ether or ester units can additionally be used and distilled off completely or partially or completely in the case of, N-methylpyrrolidone, N-ethylpyrrolidone in remain the dispersion. However, apart from the customary aliphatic, ketofunctional solvents, preference is given to no other

Solvent used.

Subsequently, the constituents of Al) to A4), which are optionally not added at the beginning of the reaction, are metered in.

In the preparation of the polyurethane prepolymer from Al) to A4), the quantitative ratio of isocyanate groups to isocyanate-reactive groups is 1.05 to 3.5, preferably 1.2 to 3.0, particularly preferably 1.3 to 2.5 ,

The reaction of the components Al) to A4) to the prepolymer takes place partially or completely, but preferably completely. Thus, polyurethane prepolymers containing free isocyanate groups are obtained in bulk or in solution.

In the neutralization step for the partial or complete conversion of potentially anionic groups to anionic groups, bases such as tertiary amines, e.g. Trialkylamines having 1 to 12, preferably 1 to 6 carbon atoms, particularly preferably 2 to 3 carbon atoms used in each alkyl radical or alkali metal bases such as the corresponding hydroxides.

Examples of these are trimethylamine, triethylamine, methyldiethylamine, tripropylamine, N-methylmorpholine, methyldiisopropylamine, ethyldiisopropylamine and diisopropylethylamine.

The alkyl radicals may, for example, also carry hydroxyl groups, as in the dialkyl monoalkanol, alkyldialkanol and trialkanolamines. If appropriate, inorganic bases such as aqueous ammonia solution or sodium or potassium hydroxide can also be used as neutralizing agents.

Preference is given to ammonia, triethylamine, triethanolamine, dimethylethanolamine or diisopropylethylamine, and sodium hydroxide and potassium hydroxide are particularly preferred

Sodium hydroxide and potassium hydroxide.

The Stoffinenge of the bases is 50 and 125 mol%, preferably between 70 and 100 mol% of the Stoffinenge of the acid groups to be neutralized. The neutralization can also take place simultaneously with the dispersion in which the dispersing water already contains the neutralizing agent.

Subsequently, in a further process step, if not yet done or only partially done, the resulting prepolymer with the aid of aliphatic ketones such as acetone or 2-butanone.

In the chain extension in step B), NH ₂ - and / or NH-functional com- ponents with the remaining isocyanate groups of the prepolymer be partially or fully implemented. Preferably, the chain extension Z-termination is stirred in water prior to dispersion.

For chain termination, amines Bl) are usually used with an isocyanate-reactive group, such as methylamine, ethylamine, propylamine, butylamine, octylamine, laurylamine, stearylamine, isononyloxypropylamine, dimethylamine, diethylamine, dipropylamine,

Dibutylamine, N-methylaminopropylamine, diethyl (methyl) aminopropylamine, morpholine, piperidine, or suitable substituted derivatives thereof, amide amines of diprimary amines and monocarboxylic acids, monoketime of diprimary amines, primary / tertiary amines such as N, N-dimethylaminopropylamine.

If anionic or potentially anionic hydrophilicizing agents corresponding to the definition B2) with NH ₂ or NH groups are used for the partial or complete chain extension, the chain extension of the prepolymers preferably takes place before the dispersion.

The aminic components B1) and B2) can optionally be used individually or in mixtures in water- or solvent-diluted form in the process according to the invention, it being possible in principle for any order of addition to be possible. When water or organic solvents are used as the diluent, the diluent content in the chain-extending component used in B) is preferably 70 to 95% by weight.

The dispersion preferably takes place after the chain extension. To this end, the dissolved and chain extended polyurethane polymer is optionally sheared under high shear, e.g. vigorous stirring, either added to the dispersing water or, conversely, the dispersing water is stirred into the chain-extended polyurethane polymer solutions. Preferably, the water is added to the dissolved chain-extended polyurethane polymer.

The solvent still present in the dispersions after the dispersion step is then usually removed by distillation. A removal already during the dispersion is also possible.

The residual content of organic solvents in the polyurethane dispersions (I) is typically less than 1.0% by weight, based on the total dispersion.

The pH of the polyurethane dispersions (I) essential to the invention is typically less than 9.0, preferably less than 8.5, more preferably less than 8.0 and most preferably 6.0 to 7.5.

The solids content of the polyurethane dispersions (I) is 40 to 70, preferably 50 to 65, particularly preferably 55 to 65 wt .-%.

The polyurethane dispersions (I) can be functionalized or functionalized via hydroxyl or amino groups. In addition, in a non-preferred embodiment, the dispersions (I) may also have reactive groups in the form of blocked isocyanate groups, as described, for example, in DE-A 19 856 412.

As coagulants (H) it is possible to use in the compositions all polyurethane-polyurea dispersions containing at least 2 cationic groups. Preference is given to polyurethane-polyurea dispersion whose particles are substantially crosslinked by urea groups. The corresponding cationically hydrophilicized polyurethane-polyurea dispersion (H) are prepared from

Cl) polyisocyanate components, as described in Al) by reaction with

C2) isocyanate-reactive compounds containing cationic groups or cationic groups überfuhrbare units and optionally with

C3) nonionically hydrophilizing compounds of the components described in A4) and optionally with

C4) the polymeric polyols mentioned in A2) and / or the hydroxy-functional compounds described in A3),

with subsequent dispersing of the prepolymers formed in water, which build up urea bonds from remaining isocyanate groups.

As the hydrophilicizing agent C3) for the polyurethane-polyurea dispersion (DT) for isocyanate-reactive compounds are used which contain cationic groups or units convertible into cationic groups. Examples of isocyanate-reactive

Groups are Hydroxlgruppen, primary or secondary amines are any hydroxy- and / or amino-functional mono- and especially bifunctional compounds having at least one tertiary amine nitrogen atoms, their tertiary nitrogen atoms during or after completion of the isocyanate polyaddition reaction by neutralization or Qua teraisierung at least partially can be converted into quaternary ammonium groups.

These include, for example, compounds such as 2- (N, N-dimethylamino) -ethylamine, N-methyl-diethanolamine, N-methyl-diisopropanolamine, N-ethyl-diethanolamine, N-ethyl-diisopropanolamine, N, N'-bis- (2-hydroxyethyl) -perhydropyrazine, N-methyl-bis (3-aminopropyl) -amine, N-methyl-bis (2-aminoethyl) -amine N, N'-, N "-trimethyl-diethylenetriamine, N ₅ N- Dimethylaminoethanol, N, N-diethylaminoethanol, 1-N, N-diethylamino-2-aminoethane, 1-

N, N-diethylamino-3-aminopropane, 2-dimethylaminomethyl-2-methyl-propanediol-1,3, N-isopropyl-diethanolamine, N-butyl-diethanolamine, N-isobutyl-diethanolamine, N-oleyl-di-ethanolamine, N-stearyldiethanolamine, ethoxylated coconut fatty amine, N-allyl-diethanolamine, N-methyl-diisopropanolamine, N-propyldiisopropanolamine and / or N-butyl-diisopropanolamine. The incorporation of quaternary ammonium groups and tert. amino groups side by side or incorporation of mixtures of said aminofunctional hydrophilicizing agents is possible.

In order to generate the cationic hydrophilization, the incorporation of the ionic groups, i. the ternary or quaternary ammonium groups, preferably with the concomitant use of tert. Amino constituent structural components, followed by transfer of the tert. Amino groups into the corresponding ammonium groups by neutralization with inorganic or organic acids, e.g. Hydrochloric acid, acetic acid, fumaric acid, adipic acid, maleic acid, lactic acid, tartaric acid, oxalic acid, N-methyl-N- (methylaminocarbonyl) -aminomethanesulfonic acid or phosphoric acid or by quaternization with suitable quaternizing agents, such as e.g. Methyl chloride, methyl iodide, dimethyl sulfate, benzyl chloride, ethyl chloroacetate or bromoacetamide. In principle, this neutralization or quaternization of the tert. Nitrogen-containing structural components also take place before or during the isocyanate polyaddition reaction, although this is less preferred. It is also possible ternary or quaternary ammonium groups in the

Polyisocyanate polyaddition products over tert. Having amino groups, as used polyether polyols with subsequent neutralization or quaternization of the tert. Introduce amino groups. The incorporation of quaternary ammonium groups and tert. Amino groups next to each other or mixtures is possible. The neutralization can also be carried out simultaneously with the dispersion in water, for example by dissolving the neutralizing agent in water, parallel addition of the neutralizing agent and the water or by adding the neutralizing agent after the addition of the water.

The degree of neutralization or quaternization is generally set between 20 and 300%, preferably 50 to 200% and more preferably between 70 and 130%.

The production of the cationically hydrophilicized polyurethane-polyurea dispersions (II) is carried out analogously to the principles and methods described for anionically hydrophilicized polyurethane dispersions (I).

In a preferred embodiment for the preparation of the cationically hydrophilicized polyurethane-polyurea dispersions (H), the components Cl) to C4) are used in the following amounts, the individual amounts always adding up to 100% by weight:

From 20 to 95% by weight of component Cl), from 3 to 30% by weight of component C2), 0 to 50 wt .-% sum of the components C3) 0 to 50 wt .-% sum of the components C4).

In a particularly preferred embodiment for the preparation of the cationically hydrophilicized polyurethane-polyurea dispersions (II), the components Cl) to C4) are used in the following amounts, the individual amounts always adding up to 100% by weight:

40 to 90 wt .-% component Cl), 5 to 20 wt .-% component C2), 0 to 30 wt .-% sum of the components C3) 0 to 30 wt .-% sum of the components C4).

Preferred cationically hydrophilized polyurethane-polyurea dispersions (IT) are prepared by using polyisocyanates Al) having an average isocyanate functionality of greater than or equal to 3, wherein crosslinking takes place within the water by reacting the water with the isocyanate groups to form urea bonds dispersed particles is achieved.

The cationically hydrophilicized polyurethane-polyurea dispersions (H) generally have a solids content of from 10 to 65% by weight, preferably from 20 to 55% by weight, particularly preferably from 25 to 40% by weight.

Preferred cationically hydrophilized polyurethane-polyurea dispersions (IT) contain particles having a particle size of from 10 to 800 nm, preferably from 20 to 500 nm.

The amount of cationic or potentially cationic groups on the particle surface, measured by an acid-base titration is generally between 20 to 5000 .mu.mol, preferably from 300 to 4000 .mu.mol per gram of solids.

As foam stabilizers (HI), known commercially available compounds are used, such as, for example, water-soluble fatty acid amides, sulfosuccinamides, hydrocarbon sulfonates or soap-like compounds (fatty acid salts), for example those in which the lipophilic radical contains from 12 to 24 carbon atoms; in particular alkanesulfonates having 12 to 22 carbon atoms in the hydrocarbon radical, alkylbenzenesulfonates having 14 to 24 carbon atoms in the entire hydrocarbon radical, or fatty acid amides or soap-like fatty acid salts of fatty acids having 12 to 24 carbon atoms. The water-soluble fatty acid amides are preferably fatty acid amides of mono- or di- (C ₂ - ₃ alkanol) amines. The soap-like fatty acid salts may be, for example, alkali metal salts, amine salts or unsubstituted ammonium salts. Suitable fatty acids are generally known compounds, for example lauric acid, myristic acid, palmitic acid, oleic acid, stearic acid, ricinoleic acid, behenic acid or arachidic acid, or even technical fatty acids, for example coconut fatty acid, tallow fatty acid, soybean fatty acid or technical oleic acid, and their hydrogenation products.

The foam stabilizers (IH) are expediently those which decompose neither under foaming conditions nor under application conditions.

Preferably, a mixture of sulfosuccinamides and ammonium stearates is used. The mixture of sulfosuccinamides and ammonium stearates preferably contains between

20 and 60 wt .-% ammonium stearates, particularly preferably 30 to 50 wt .-% of ammonium stearates and preferably 80 and 40 wt .-% sulfosuccinamides, particularly preferably 70 to 50 wt .-% sulfosuccinamides, wherein the weight percentages on the refer to non-volatile components of both Schaumstablisatorklassen and add the wt .-% shares both to 100 wt%.

Crosslinking agents (FV) are also present in the coating compositions according to the invention. Depending on the choice of crosslinker (IV) and the aqueous polyurethane dispersion (I), both one-component systems and two-component systems can be prepared. In the context of the present invention, single-component coating systems are to be understood as meaning layering agents in which binder component (I) and crosslinker component (IV) can be stored together without a crosslinking reaction taking place in appreciable extent or harmful to the subsequent application. In the context of the present invention, two-component coating systems are coating compositions in which binder component (I) and crosslinker component (IV), because of their high reactivity, have to be stored in separate vessels. The two components are mixed just before application and then generally react without additional activation. Suitable crosslinkers IV) are, for example, blocked or unblocked polyisocyanate crosslinkers, amide and amine-formaldehyde resins, phenolic resins, aldehyde and ketone resins, for example phenol-formaldehyde resins, resols, furan resins, urea resins, carbamic acid ester resins, triazine resins, melamine resins, benzoguanamine resins, cyanamide resins or aniline resins. Preference is given to melamine-formaldehyde resins, it being possible for up to 20 mol% of the melamine to be replaced by equivalent amounts of urea. Particularly preferred is methylolated melamine, for example bi-tri- and / or tetramethyolmelamine. The melamine-formaldehyde resins are usually used in the form of their concentrated aqueous solutions whose solids content is from 30 to 70% by weight, preferably from 35 to 65% by weight, and particularly preferably from 40 to 60% by weight.

Commercially available thickeners can be used as thickener (V), such as dextrin, starch or cellulose derivatives such as cellulose ethers or hydroxyethylcellulose, organic fully synthetic thickeners based on polyacrylic acids, polyvinylpyrrolidones, poly (meth) acrylic compounds or polyurethanes (associative thickeners). and inorganic thickeners, such as Betonite or silicic acids.

The compositions essential to the invention contain, based on dry matter, typically 80 to 99.5 parts by weight of dispersion (I), 0.5 to 5 parts by weight of cationic coagulant (H), 0.1 to 10 parts by weight of foaming aid (IH), 0 to 10 parts by weight of crosslinking agent ( W) and 0 to 10 wt .-% thickener (V).

Preferably, the compositions essential to the invention contain 85 to 97 parts by weight of the dispersion (I), 0.75 to 4 parts by weight of the cationic coagulant (Q), 0.5 to 6 parts by weight of foaming aid (IH), 0.5 to 5 parts by weight Crosslinker (IV) and 0 to 5 wt .-% thickener (V).

The compositions essential to the invention particularly preferably contain 89 to 97 parts by weight of the dispersion (I), 0.75 to 3 parts by weight of the cationic coagulum (H), 0.5 to 5 parts by weight of foam auxiliaries (III), 0.75 to 4 parts by weight. parts by weight of crosslinker (TV) and 0 to 4 parts by weight of thickener (V).

In addition to the components (I) - (V), it is also possible to use other aqueous binders in the compositions essential to the invention. Such aqueous binders may, for. B. of polyester, polyacrylate, polyepoxide or other polyurethane polymers. The combination with radiation-curable binders, as z. As described in EP-A-O 753 531, is possible. It is also possible to use other anionic or nonionic dispersions, such as polyvinyl acetate, polyethylene, polystyrene, polybutadiene, polyvinyl chloride, polyacrylate and copolymer dispersions.

The foaming in the process according to the invention is done by mechanical stirring of the composition at high speeds, ie under entry of high shear forces or by relaxation of a propellant gas such. B. the injection of compressed air. The mechanical foaming can be carried out with any mechanical stirring, mixing and dispersing techniques. As a rule, this air is entered, but also nitrogen and other gases can be used for this purpose.

The preparation of the coating compositions of the invention from the components I-V.) Is carried out by homogeneous mixing of all components in any order according to the methods known in the art. The component π can also be added during or after the foaming step.

The coating compositions of the invention may additionally contain antioxidants and / or light stabilizers and / or other auxiliaries and additives such as emulsifiers, defoamers, thickeners. Finally, too

Fillers, plasticizers, pigments, silica sols, aluminum, clay, dispersions, leveling agents or thixotropic agents may be included. Depending on the desired property profile and intended use of the PU-based coating compositions of the invention, up to 70% by weight, based on the total dry matter, of such fillers may be present in the end product.

Furthermore, it is possible to modify the coating compositions according to the invention by polyacrylates. For this purpose, in the presence of the polyurethane dispersion, an emulsion polymerization of olefinically unsaturated monomers, for. Esters of (meth) acrylic acid and alcohols having 1 to 18 carbon atoms, styrene, vinyl esters or butadiene, e.g. in DE-A 1 953 348, EP-A 0 167 188, EP-A 0 189 945 and EP-A

A 0 308 115 is described. The monomers contain one or more olefinic double bonds. In addition, the monomers may contain functional groups such as hydroxyl, epoxy, methylol or acetoacetoxy groups.

Another object of the present invention is the use of the novel coating compositions for the production of microporous coatings on a variety of substrates.

Suitable support materials are in particular textile fabrics, sheet substrates of metal, glass, ceramics, concrete, natural stone, leather, natural fibers, and plastics such as PVC, polyolefins, polyurethane or the like.

Under textile fabrics in the sense of the present invention are, for example

Tissues, knitted fabrics, bound and unbonded nonwovens to understand. The textile fabrics can be constructed from synthetic, natural fibers and / or mixtures thereof be. In principle, textiles made of any desired fibers are suitable for the process according to the invention.

The coating compositions according to the invention are stable and, depending on the composition, usually have a processing time of up to a maximum of 24 hours.

Because of their excellent extensibility at high tensile strengths after film formation, the novel coating compositions are particularly suitable for producing microporous coatings on flexible substrates.

The production of the microporous coatings takes place in which the novel coating compositions comprising the components L) -V.) Are first foamed.

The foaming in the process of the invention is accomplished by mechanically stirring the composition at high speeds, i. under the action of high shear forces or by relaxation of a propellant gas, e.g. the injection of compressed air.

The mechanical foaming can be carried out with any mechanical stirring, mixing and dispersing techniques. As a rule, this air is entered, but also nitrogen and other gases can be used for this purpose.

The foam thus obtained is applied to a substrate during foaming or immediately thereafter or placed in a mold and dried.

A multi-layer application with intervening drying steps is also possible in principle.

For a faster drying and fixing of the foams, however, temperatures above 30 ^° C. are preferably used. During the drying, however, temperatures of 200 ^° C., preferably 160 ^° C., should not be exceeded. Also useful is a two- or multi-stage drying, with a correspondingly rising temperature gradient, in order to prevent the coating from being boiled up.

The drying is usually carried out using known heating and drying apparatus, such as (convection) drying cabinets, hot air or IR-Strahlem. Drying by passing the coated substrate over heated surfaces, eg rollers, is also possible. The application and the drying can each be carried out batchwise or continuously, but a completely continuous process is preferred.

Before being dried, the polyurethane foams typically have foam densities of 50 to 800 g / liter, preferably 200 to 700 g / liter, particularly preferably 300 to 600 g / liter (mass of all starting materials [in g] relative to the foam volume of one liter). ,

After being dried and coagulated, the polyurethane foams have a microporous, at least partially open-pore structure with cells which communicate with one another. The density of the dried foams is typically 0.3-0.7 g / cm ³ , preferably 0.3-0.6 g / cm ^3, and very particularly preferably 0.3-0.5 g / cm ³ .

The polyurethane foams have good mechanical strength and high elasticity.

Typically, the values for the maximum tensile strength are greater than 0.2 N / mm ² and the maximum elongation is greater than 250%. Preferably, the maximum tensile strength is greater than 0.4 N / mm ² and the elongation greater than 350% (determined according to DIN 53504).

The polyurethane foams after drying typically have a thickness of 0.1 mm to 50 mm, preferably 0.5 mm to 20 mm, more preferably 1 to 10 mm, most preferably 1 to 5 mm.

The polyurethane foams can also be bonded, laminated or coated with other materials, for example based on hydrogels, (semi-) permeable films, coatings or other foams.

The foamed composition is then coated with conventional coating equipment, such as a squeegee, e.g. As a doctor blade, rollers or other Schaumauftra- supply equipment, applied to the carrier. The application can be done on one or both sides. The application amount is chosen so that the weight increase after the second drying step is 30% to 100%, preferably 40% to 80% and particularly preferably 45% to 75% with respect to the textile carrier. The application quantity per m ² can be influenced by the pressure in the closed doctor blade system or by the measured value of the stencil. The wet application weight preferably corresponds to the weight of the textile carrier. The foam decay rate on the support depends on the type and amount of the foam stabilizer (III), the coagulum (H) and the ionicity of the aqueous polyurethane dispersion (I). The fixation of the resulting open-cell structure by drying at a temperature between 35 and 100 ⁰ C, preferably between 6O ⁰ C and 100 ⁰ C, more preferably at 70 to 100 ⁰ C. The drying can be done in a conventional dryer. Also possible is drying in a microwave (HF) dryer.

Subsequently, foam matrix can be fixed again in a further drying step if required. This optional additional fixing step is preferably carried out at 100 ⁰ C to 175 ° C, particularly preferably at 100 to 150 ⁰ C and most preferably at 100 ⁰ C to 139 ⁰ C, wherein the drying time is so chosen is that it is ensured, that the PUR foam matrix is sufficiently strongly crosslinked.

Alternatively, the drying and fixing in a single step following the

Coagulation by direct heating to preferably 100 to 175 ⁰ C, more preferably carried out at 100 to 150 ⁰ C and most preferably at 100 ⁰ C to 139 ⁰ C, wherein the contact time is selected in a manner sufficient drying and sufficient Fixation of the PUR foam matrix is ensured.

The dried textile supports may be surface treated before, during or after the condensation, e.g. B. by grinding, velorizing, roughening and / or tumbling.

The coating compositions according to the invention can also be applied in several layers to a carrier material, for example to produce particularly high foam deposits.

In addition, the microporous coatings according to the invention can also be used in multi-layer constructions.

The present invention also substrates are coated with the microporous coatings of the invention. Due to the excellent performance properties see the compositions of the invention or the layers produced from them in particular for coating or production of outerwear, artificial leather items, shoes, furniture upholstery fabrics, automotive interior equipment and sports equipment, this list is only exemplary and not limiting understand is. Examples:

Unless otherwise indicated, all percentages are by weight.

The solids contents were determined according to DIN-EN ISO 3251.

NCO contents were determined volumetrically in accordance with DIN EN ISO 11909, unless expressly stated otherwise.

Substances used and abbreviations:

Bayhydur ^® VP LS 2336 Hydrophilic polyisocyanate based on hexamethylene diisocyanate, solvent-free, isocyanate content approx. 16.2%, Bayer MaterialScience AG, Leverkusen, DE.

Desmodur ^® N 3300 polyisocyanate (trimer) nat based on hexamethylene, solvent-free, viscosity about 3000 mPa s, the isocyanate content of about 22%, Bayer MaterialScience AG, Leverkusen, DE

Polyether LB 25 monofunctional ethylene oxide / propylene oxide based polyether number average molecular weight 2250 g / mol, OH number 25 mg KOH / g (Bayer MaterialScience AG, Leverkusen, DE)

Isofoam ^® 16 defoamers, Petrofer chemistry, Hildesheim, DE

Diaminosulphonate: NH ₂ -CH ₂ CH ₂ -NH-CH ₂ CH ₂ -SO ₃ Na (45% in water)

Desmophen ^® C2200: polycarbonate polyol, OH number 56 mg KOH / g, number average molecular weight 2000 g / mol (Bayer MaterialScience AG, Leverkusen, DE)

PolyTHF ^® 2000: Polytetramethylenglykolpolyol, OH number 56 mg KOH / g, number average molecular weight 2000 g / mol (BASF AG, Ludwigshafen, DE)

PolyTHF ^® 1000: Polytetramethylenglykolpolyol, OH number 112 mg KOH / g, number-average number average molecular weight 1000 g / mol (BASF AG, Ludwigshafen, DE) Stokal ^® STA: ammonium stearate-based foam additive, active substance content:

30% (Bozzetto GmbH, Krefeld, DE)

Stokal ^® SR: Succinamate based foaming agent, active ingredient content: approx. 34

% (Bozzetto GmbH, Krefeld, DE)

Praestol ^® 185 K: Cationic flocculants containing the structure A, solids content 25% (Degussa AG, DE)

Euderm red azo pigment preparation, contains C.I. pigment red 170 (Lanxess

AG, Leverkusen, DE)

The determination of the average particle sizes (indicated by the number average) of the polyurethane dispersions (I) was carried out by means of laser correlation spectroscopy (apparatus: Malvern

Zetasizer 1000, Malver Inst. Limited).

charge determination

A portion of the sample is weighed to 0.0001 g (mass typically between 0.2 g and Ig, depending on the amount of charge) with a 5 wt .-% aqueous surfactant solution (Brij-96 V, Fluka, Buchs, Switzerland product no. 16011) and doubly deionized water and, after addition of a defined amount of hydrochloric acid (0.1 n, so that the mixture has a starting pH of about pH 3, KMF Laboratory Chemistry GmbH, Lohmar, Art.No .: KMF.01 -044.1000) are titrated with aqueous sodium hydroxide solution (0.05 n, Bernd Kraft GmbH, Duisburg, item no .: 01056.3000). In addition, a portion (about 30 g) of the dispersion with ion exchanger is used to differentiate the surface charge and the serum charge

Lewatit ^® VP-OC 1293 (use of the 10-fold exchange capacity based on the specific total charge, stirring time 2.0 h, Lanxess AG, Leverkusen, mixed anion / cation exchanger) treated and the resulting dispersion after filtration (ED fast sieve, cotton fabric 240 μm Fa Erich Drehkopf GmbH, Ammersbek). In the titration of the sample after ion exchange treatment, the surface charge is determined. By

Difference formation with the total charge, the serum charge can be determined.

The determination of the surface charge from the equivalence points gives, within the measurement accuracy, a comparable value to the determination of basic groups from the under-consumption of sodium hydroxide, based on the added amount of hydrochloric acid. From this it follows that the specific amounts of charge are basic and not weakly acidic groups (eg carboxyl groups). The term μeq / g stands for microequivalent per gram of solid, one equivalent is one mole of ionic groups. Positive values stand for cationic charges, negative for anionic charges.

Coagulant 1)

Cationic hydrophilic polyurethane-polyurea dispersion cross-linked by urea groups

In a stirring vessel 429.0 g (1.1 Val isocyanate groups) of Desmodur ^® N 3300 at room temperature, admixed with 71.32 g (0.4 VaI alcohol groups) of N, N-dimethylaminoethanol. It is stirred between 20 and 30 ⁰ C until an isocyanate content of 5.04% is reached (titimetric determination). Then, 48.1 g of acetic acid are added dropwise and to the resulting mixture are added with vigorous stirring 1279 g of deionized water (about 25 ° C) and 0.1 g Isofoam 16.

After about 1 hour, the resulting dispersion is evacuated to about 200 mbar pressure while stirring for about 5 hours at 20-30 ⁰ C.

The resulting white dispersion had the following properties:

Solids content: 27%

Particle size (LKS): 84 nm

Viscosity (viscometer, 23 ° C): 100 mPas pH (23 ° C): 7.25

Charge determination: total charge 3078 ± 24 μeq / g, surface charge 1379 ± 23 μeq / g

Coagulant 2)

Cationic and nonionically hydrophilicized polyurethane polyurea crosslinked by urea groups into a stirring vessel to be 215.5 g (1.1 Val isocyanate groups) of Desmodur ^® N 3300 at a

Temperature of about 5O ⁰ C added with 5.91 g (0.1 VaI) of 1,6-hexanediol and stirred for about 2 hours at 80 ⁰ C until a constant isocyanate content is reached (titimetric determination). Subsequently, 225.0 g of the polyether LB 25 are added and stirred for a further 3 hours at 80- 85 ° C until a constant isocyanate content is reached. It is then cooled to 30 ⁰ C and stirred with 26.7 gg (0.3 VaI alcohol groups) N, N-dimethylaminoethanol and about 2 hours. To the prepolymer is added a solution of 18.0 g (0.3 VaI) of acetic acid in 997 g of deionized water and 0.1 g of isofoam 16, and the resulting dispersion is vigorously stirred for about 2 hours.

Thereafter, the resulting dispersion is evacuated to about 200 mbar pressure and stirred for about 5 hours further at 20-30 ° C.

The resulting white dispersion had the following properties:

Solids content: 32%

Particle size (LKS): 784 nm

Viscosity (viscometer, 23 ⁰ C): 160 mPas pH (23 ° C): 6.46

Charge determination: total charge 1476 ± 11 μeq / g, surface charge 510 ± 2 μeq / g

Example 1: PUR Dispersion (Component I)

144.5 g of Desmophen ^® C2200, 188.3 g of PolyTHF ^® 2000, 71.3 g PolyTHF ^® 1000 and 13.5 g of polyether LB 25 were heated to 70 ⁰ C. Subsequently, at 70 ⁰ C within

5 min, a mixture of 45.2g hexamethylene diisocyanate and 59.8 g of isophorone diisocyanate was added and stirred under reflux until the theoretical NCO value was reached.

The finished prepolymer was dissolved with 1040 g of acetone at 50 ⁰ C and then a

Solution of 1.8 g of hydrazine hydrate, 9.18 g Diaminosulfonat and 41.9 g of water added within 10 min. The stirring time was 10 min. After adding a solution of 21.3 g

Isophoronediamine and 106.8 g of water were added within 10 min by addition of 254 g

Water dispersed. This was followed by removal of the solvent by distillation in vacuo.

The resulting white dispersion had the following properties:

Solids content: 60%

Particle size (LKS): 285 nm

Example 2: PUR Dispersion (Component I)

2159.6 g of a difunctional polyester polyol based on adipic acid, neopentyl glycol and hexanediol (average molecular weight 1700 g / mol, OH number = 66), 72.9 g of a monohydric Ethylene oxide / propylene oxide-based functional polyethers (70/30) (average molecular weight 2250 g / mol, OH number 25 mg KOH / g) were heated to 65 ° C. Subsequently, a mixture of 241.8 g of hexamethylene diisocyanate and 320.1 g of isophorone diisocyanate was added at 65 ° C within 5 min and stirred at 100 ° C until the theoretical NCO value of 4.79% was reached. The finished prepolymer was added with 4990 g of acetone

Dissolved 50 ° C and then added a solution of 187.1 g of isophorone diamine and 322.7 g of acetone within 2 min. The stirring time was 5 min. Subsequently, a solution of 63.6 g of diaminosulfonate, 6.5 hydrazine hydrate and 331.7 g of water was added within 5 min. The dispersion was carried out by adding 1640.4 g of water. This was followed by removal of the solvent by distillation in vacuo.

The resulting white dispersion had the following properties:

Solids content: 58.9%

Particle size (LKS): 248 nm

Preparation of foam pastes and microporous coatings from the PU dispersions of Examples 1-9.

The foam pastes produced were normally applied as an adhesive coat or as an intermediate coat on topcoats of one-component Impraperm and Impranil marks in the transfer process.

To prepare the foaming pastes from the PUR dispersions of Examples 1-9, e.g. following devices in question:

e.g. Hansa mixer

Mondo mixer

Oakes Mixer

Stork foam generator

The order of the foam was carried out by means of a doctor blade. When applying the wet foam, the squeegee gap should be between 0.3mm and 0.5mm. The foam density should be 300-600g / l.

When setting the laminating the distance between the two rolls generally corresponded to the total thickness of substrate, foam wet application and the paper thickness. The substrates used for the foam coating are woven and knitted fabrics made of cotton as well as nonwovens made of cellulose fibers and mixtures thereof. The substrates can be roughened as well as roughened. The coating was preferably made on the non-roughened side. For the production of clothing articles are substrates of 140-200 g / m ² , suitable for shoe up to 240 g / m ² .

For dyeing the coating pastes from the PU dispersions of Examples 1-9, the following colored doughs can be used:

e.g. Levanox brands about 10%

Levanyl marks ca.6% Isoversal WL ca.10%

Euderm brands ca.12- 15%

Eukanol brands about 10%

Preferred are opaque colors such as Euderm brands.

When preparing the paste, the PU dispersions of the examples were initially charged with about 1% of a 25% strength ammonia solution in a sufficiently large container.

The pH reached 7.5-8.5 in order to make a final, foam-stabilizing thickening can.

Then 2.0-2.5% of the foam stabilizer Stokal SR and to 1.0-1.5% of the ammonium stearate Stokal STA were added while stirring with one of the above-mentioned devices.

After a first homogenization, a desired pigmentation could then optionally be carried out.

After the distribution of the pigments of Melaminharzvernetzer Acrafix ^® ML was added at about 1.0 to 1.5%.

Subsequently, at a speed of about 1500-2000 rpm, the desired weight per liter could be set.

With further stirring, the obtained foams were finally coagulated by addition of the cationic coagulant ET); Coagulation left the foam volume and the viscosity unchanged. Alternatively, the addition of the cationic coagulant H) could also take place before the foaming step.

Optionally, thickeners were added to adjust a viscosity of, for example, 6000 to 8000 mPas. The thickener amounts used are generally between 0.1 to 5%.

The drying, or crosslinking of the foam was performed in a drying channel 3 zones (Zone 1: 80 ⁰ C, Zone 2: 100 ⁰ C, Zone 3: 160 ⁰ C).

Pure white or red-colored foams with good mechanical properties and a fine microporous pore structure were consistently obtained.

Table 1

The foams 1-6 all have a fine micro-porous structure and a high proportion of corresponding cells. The foam has a very even distribution of the pores.

If the coagulant is dispensed with (formulation foam 9), a closed-cell, non-micro-porous foam is obtained.

Substituting Praestol ^® 185 K as a coagulant (foam 7 and 8) is an increase in viscosity after the mixing, which makes the further processing, and sets the processing time reduced. In particular, by adding thickeners such as Mirox ^® AL (Ex. 8), the processability is ness reduced so much so that no foam can be generated. Further, in use of Praestol ^®, the resulting microstructure of the foam (foam 7) is 185 K coarser.

By using premature coagulation when using Prästol ^® 185 K as coagulant (foam 7) the foam is fuzzy. Therefore, it must be refiltered before coating, this step is not necessary when using the cationic coagulants (II) (foam 1-6).

Claims

claims

1. A process for the preparation of microporous coatings in which a composition containing an aqueous, anionically hydrophilicized polyurethane dispersions (I) and a cationic coagulant (H) comprising a cationically hydrophilicized Poly urethane polyurea dispersion is foamed and dried.

2. The method according to claim 1, characterized in that it is carried out using aqueous, anionic hydrophilic polyurethane dispersions (I), which are obtainable by

A) isocyanate-functional prepolymers

Al) organic polyisocyanates

A2) polymeric polyols having number average molecular weights of 400 to 8000 g / mol and OH functionalities of 1.5 to 6 and

A3) optionally hydroxy-functional compounds having molecular weights of 62 to 400 g / mol and

A4) optionally isocyanate-reactive, anionic or potentially anionic and optionally nonionic hydrophilicizing agents,

getting produced,

B) whose free NCO groups then wholly or partly

Bl) with amino-functional compounds having molecular weights of 32 to 400 g / mol and / or

B2) amino-functional, anionic or potentially anionic hydrophilicizing agents

are reacted with chain extension and the prepolymers are dispersed in water before, during or after step B), possibly containing potentially ionic groups are converted by partial or complete reaction with a neutralizing agent in the ionic form.

3. The method according to claim 2, characterized in that in the preparation of the aqueous, anionic hydrophilic polyurethane dispersions (I) in Al) 1,6- Hexamethylene diisocyanate, isophorone diisocyanate, the isomeric bis (4,4'-isocyanatocyclohexyl) methanes, and mixtures thereof are used and in A2) a mixture of polycarbonate polyols and Polytetramethylenglykolpolyo- len is used, wherein the proportion of the sum of the polycarbonate and poly tetramethylene glycol polyether polyols on component A2) at least 70

Wt .-% is.

4. The method according to any one of claims 1 to 3, characterized in that in addition to the polyurethane dispersion (I) and the cationic coagulant (Η) and auxiliaries and additives (TU) are included.

5. The method according to claim 4, characterized in that as auxiliaries and additives

(UI) water-soluble fatty acid amides, sulfosuccinamides, hydrocarbon sulfonates, hydrocarbon sulfates or fatty acid salts are used as foaming agents and foam stabilizers.

6. The method according to claim 5, characterized in that as foaming agents and foam stabilizers mixtures of sulfosuccinamides and ammonium stearates are used, these containing 70 to 50 wt .-% of sulfosuccinamides.

7. Microporous coatings obtainable by a process according to one of claims 1 to 6.

8. Microporous coatings according to claim 7, characterized in that they have a microporous, open-pored structure and have a density in the dried state of 0.3-0.7 g / cm ³ .

9. Compositions comprising an aqueous, anionically hydrophilicized polyurethane dispersions (I) and a cationic coagulant (H) comprising a cationically hydrophilicized polyurethane-polyurea dispersion.

10. Substrates coated with microporous coatings according to claims 7 and 8.

11. Substrates according to claim 10 selected from the group consisting of outerwear, imitation leather articles, shoes, upholstery fabrics, automotive interior equipment, sports equipment.