ES2458426T3 - Textile Coating Procedure - Google Patents

Abstract

Production process of coated textile materials, comprising at least the steps of a) contacting a textile substrate with an aqueous dispersion A comprising at least one inorganic salt and at least one modified cellulose, b) contacting a textile substrate with an aqueous dispersion B comprising polyurethane and c) precipitating the polyurethane in or on the textile substrate.

Description

Textile Coating Procedure

The present invention relates to a process for producing coated textile materials in which a textile substrate is first contacted with an aqueous dispersion comprising at least one inorganic salt and at least one modified cellulose.

The production of synthetic leather covering textile materials with plastics has been known for some time. Synthetic leathers are used, among other things, as materials for the upper part of footwear, for articles of clothing, as material for manufacturing bags or in the upholstery sector, for example. In addition to other plastics, such as PVC, the main coating material used here is polyurethane. Generally known principles of coating textile materials with polyurethane are described in W. Schröer, "Textilveredlung [Textile Finishing]" 1987, 22 (12), 459-467. A description of the coagulation procedure is also found in "New Materials Permeable to Water Vapor", Harro Träubel, Springer Verlag, Berlin, Heidelberg, New York, 1999, ISBN 3-540-64946-8, pages 42 to 63.

The main procedures used in the production of synthetic leather are the direct coating process, the transfer coating procedure (indirect coating) and the coagulation procedure (wet). In contrast to the direct procedure, the coating in the transfer process is applied to a temporary support with a subsequent lamination step, in which the film is combined with the textile substrate and is detached from the temporary support (removable paper). The transfer process is preferably used with textile substrates that do not allow high tensile stresses during coating.

or with open tissues that are not particularly dense.

In the coagulation process, a textile substrate is usually coated with a solution comprising polyurethane in DMF. In a second stage, the coated substrate is passed through DMF / water baths, in which the proportion of water increases in stages. Precipitation of polyurethane and the formation of a microporous film occur here. Use is made here of the fact that DMF and water have excellent miscibility and DMF and water serve as a solvent / non-solvent pair for polyurethane. Coagulated polyurethane coatings are used, in particular, for high quality synthetic leather, since they have a comparatively good perspiration activity and leather feel. The basic principle of the coagulation process is based on the use of a solvent / non-solvent pair suitable for polyurethane. The great advantage of the coagulation procedure is that a microporous synthetic leather with perspiration activity that has an excellent leather feel can be obtained. Examples are, for example, the synthetic leather of Clarino® and Alcantara® brands. The need to use large quantities of DMF as an organic solvent is a disadvantage of the coagulation process. To minimize the exposure of employees to DMF emissions during production, additional design measures have to be taken that represent a significantly increased outlay compared to simpler procedures. In addition, it is necessary to discard or process large quantities of DMF / water mixtures. This is problematic, since water and DMF form an azeotrope and, therefore, can only be separated by distillation with increased effort.

US2004 / 121113 already describes a solvent-free process for the production of coated textile materials, which comprises the step of contacting a textile substrate with an aqueous polyurethane dispersion, followed by a precipitation step. The polyurethane dispersion contains a modified cellulose as a thickener and its pH is adjusted to approximately 8 to 10 using ammonium hydroxide.

Therefore, it was an object of the present invention to develop a process for coating textile substrates that still makes it possible to obtain coated textile materials that have good properties, such as, for example, good touch, without the need to use toxicologically unacceptable solvents such as , for example, DMF.

The object has been achieved by a process for the production of coated textile materials comprising at least the stages of

a) contacting a textile substrate with an aqueous dispersion A comprising at least one inorganic salt and at least one modified cellulose,

b) contacting a textile substrate with an aqueous dispersion B comprising polyurethane and

c) precipitate the polyurethane in or on the textile substrate.

In step a), a textile substrate is contacted with an aqueous solution comprising at least one inorganic salt and at least one modified cellulose.

The inorganic salt is preferably a salt selected from the group comprising alkali metal salts and alkaline earth metal salts. The inorganic salt is with particular preference a salt selected from the group consisting of alkali metal halides, alkali metal phosphates, alkali metal nitrates, sulfates of

alkali metals, alkali metal carbonates, alkali metal hydrogen carbonates, alkaline earth metal halides, alkaline earth metal nitrates, alkaline earth metal phosphates, alkaline earth metal sulfates, alkaline earth metal carbonates and alkaline earth metal carbonates. Inorganic salt is very particularly preferred sodium chloride, potassium chloride, sodium sulfate, sodium carbonate, potassium sulfate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, magnesium chloride, magnesium sulfate, magnesium nitrate, calcium chloride, calcium nitrate or calcium sulfate The inorganic salt is even more preferably calcium nitrate, magnesium nitrate, calcium chloride or magnesium chloride.

The inorganic salt is preferably present in the dispersion A in an amount of 0.01 to 25% by weight, particularly preferably in an amount of 0.5 to 15% by weight, and very particularly preferably in an amount of 0, 5 to 10% by weight, based on the total amount of dispersion A.

Chemically modified cellulose is preferably a compound selected from the group consisting of alkylated celluloses, hydroxyalkylated celluloses and carboxyalkylated celluloses.

Chemically modified cellulose is, with particular preference, a compound selected from the group consisting of methyl cellulose, ethyl cellulose, propyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, carboxy methyl cellulose and carboxypropyl cellulose.

Chemically modified cellulose is very particularly preferably methyl cellulose or ethyl cellulose.

The modified cellulose is preferably present in the dispersion A in an amount of 10 ppm to 5% by weight, particularly preferably in an amount of 100 ppm to 3% by weight, most particularly preferably in an amount of 400 ppm to 1, 5% by weight, based on the total amount of dispersion A.

The textile substrate is preferably contacted with an aqueous dispersion A at room temperature for a period of 2 to 4 minutes, particularly preferably 1 to 2 minutes, with particular preference of 0.2 to 1 minute. For the purposes of the present invention, contacting means partial or complete immersion, preferably complete immersion, in a dispersion or application of the dispersion by a manual coater, by printing or spraying.

After bringing it into contact with the dispersion A, the textile substrate is preferably passed through a draining device consisting of two rollers to remove excess dispersion A. Here, the draining device should preferably be adjusted such that the dispersion A remained in the textile substrate in an amount of 60 to 180% by weight, with particular preference of 70 to 140% by weight, with very particular preference of 80 to 120%, based on the weight per unit area of the substrate (uptake of liquor) before contacting the substrate with dispersion B containing polyurethane. The textile substrate is preferably partially dried for a period of 2 to 10 minutes, particularly preferably 1 to 5 minutes, using air, infrared or hot cylinders before it can be contacted with the dispersion B containing polyurethane.

The polyurethane present in dispersion B is not particularly limited on condition that it is soluble in water, the term "polyurethane" also comprising polyurethane-polyureas. A recapitulation of the polyurethane dispersions (PUR) and procedures for this can therefore be found in Rosthauser and Nachtkamp, "Waterbome Polyurethanes, Advances in Urethane Science and Technology", vol. 10, pages 121-162 (1987). Suitable dispersions are also described, for example, in "Kunststoffhandbuch [Plastics Handbook]", vol. 7, 2nd edition, Hauser, pages 24 to 26.

The constituent components of the dispersions B used in accordance with the invention may be the following:

1) Organic di-and / or polyisocyanates such as, for example, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 2-methylpentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (THDI), dodecanemethylene diisocyanate 1, 4-diisocyanate-3-isocyanate-3-isocyano-cyclohenyl-3-isocyano-cyclohenyl-3-isocyano-cyclohenyl-3-isocyanathenyl-3-diisocyanoc-3-isocyanathenyl-3-isocyano-cyclohenyl 5-Trimethylcyclohexyl isocyanate (isophorondiisocyanate = IPDI), 4,4'-diisocyanodicyclohexylmethane (Desmodur® W), 4,4'-diisocyanate-3'3'-dimethyldicyclohexylmethane, 4,4'-diisocyanate-2,2-dicyclohexylbenzene-1, 4-4-dihydrobenzene , 2,4-or 2,6-diisocyanatotoluene or mixtures of these isomers, 4,4'-, 2,4

or 2,2'-diisocyanatodiphenylmethane or mixtures of these isomers, 4,4-, 2,4'-or 2,2'-diisocyanate-2,2-diphenylpropane-pxylenediisocyanate and α, α, α ', α'-tetramethyl -mo-p-xylenediisocyanate (TMXDI) and mixtures consisting of these compounds. For modification purposes, small amounts of trimers, urethanes, biurets, allophanates or uretdiones of the diisocyanates mentioned above may be used. Particularly preferred are MDI, Desmodur W, HDI and / or IPDI.

2) Polyhydroxy compounds having 1 to 8, preferably 1.7 to 3.5, hydroxyl groups per molecule and a molecular weight (average) of up to 16,000, preferably up to 4,000. Low molecular weight polyhydroxy compounds defined in each case can be considered as, for example, ethylene glycol, 1,2-, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, glycerol, the product of reaction of 1 hydrazine + 2 propylene glycol and oligomeric or polymeric hydroxy compounds with molecular weights of 350 to 10,000, preferably 840 to 3,000.

Relatively high molecular weight hydroxy compounds include hydroxy polyesters, hydroxypolyethers, hydroxypolythioethers, hydroxypolycetacetes, hydroxypolycarbonates and / or hydroxypolyethermodes that are known per se in polyurethane chemistry, preferably those having average molecular weights of 350 to 4,000, particularly those they have average molecular weights of 840 to 3,000. Particularly preferred are hydroxypolycarbonates and / or hydroxypolyethers. When used, coagulates having a particular stability against hydrolysis can be prepared.

3a) Ionic or potentially ionic hydrophilizing agents containing an acid group and / or an acid group in the form of salt and at least one isocyanate reactive group, for example, an OH or NH2 group. Examples are the sodium salt of ethylenediamine-β-ethyl sulphonic acid (AAS salt solution), dimethylpropionic acid (DMPA), dimethylolbutyric acid, hydroxypropyl acid or adducts of 1 mol of diamine, preferably isophorondiamine, and 1 mol of a carboxylic acid α, β-unsaturated, preferably acrylic acid.

3b) Non-ionic hydrophilizing agents in the form of mono- and / or difunctional poly (ethylene oxide) or poly (ethylene oxide) alcohols having molecular weights of 300 to 5,000. Particularly preferred are monohydroxy-functional ethylene oxide / propylene oxide polyethers based on n-butanol having 35 to 85% by weight of ethylene oxide units and molecular weights of 900 to 2,500. A content of at least 3% by weight, in particular at least 6% by weight, of non-ionic hydrophilizing agents is preferred.

4) Isocyanate group blocking agents such as oximes (acetonoxime, butanonoxime or cyclohexanonoxime), secondary amines (diisopropylamine, dicyclohexylamine), acidic heterocyclic substances in NH (3'5-dimethylpyrazole, imidazole, 1'2,4- triazole), acid esters in CH (C1-4 alkyl malonates, acetic acid esters) or lactams (ε-caprolactam). Particularly preferred are butanoxime, diisopropylamine and 1,2,4-triazole.

5) Polyamines as incorporated chain extenders. These include, for example, the polyamines discussed in 6). The diaminofunctional hydrophilizing agents discussed in 3a) are also suitable as chain extenders to be incorporated.

6) Polyamine crosslinking agents. These are preferably aliphatic or cycloaliphatic diamines, although it is also possible, if necessary, to use trifunctional polyamines or polyfunctional polyamines to achieve specific properties. In general, it is possible to use polyamines containing additional functional groups such as, for example, OH groups. Polyamine crosslinking agents, which are not incorporated into the polymeric skeleton at normal or slightly elevated ambient temperature, for example at 20 to 60 ° C, are added by mixing immediately during the preparation of the reactive dispersions or at a later time. Examples of suitable aliphatic polyamines are ethylenediamine, 1,2- and 1,3-propylenediamine, 1,4-tetramethylenediamine, 1,6-hexamethylenediamine, the isomeric mixture of 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 2- methylpentamethylenediamine and diethylenetriamine.

In a further preferred embodiment, the dispersion B comprises at least one coagulant in addition to the polyurethane. A coagulant is a salt or acid, for example ammonium salts of organic acids, which causes coagulation of the polyurethane under certain conditions such as, for example, a particular temperature. These substances include an acid generating chemical agent, specifically a substance that is not an acid at room temperature, but which becomes acid after heating. Certain examples of such compounds include ethylene glycol diacetate, ethylene glycol formate, diethylene glycol formate, triethyl citrate, monostearyl citrate and an organic acid ester.

The coagulant is preferably present in the composition in an amount of 1 to 10% by weight, based on the solids content of dispersion B.

The polyurethane present in the dispersion B is preferably anionic and / or non-ionic hydrophilized polyurethane which is obtainable by

A) the preparation of isocyanate-functional prepolymers from

A1) organic polyisocyanates

A2) polymer polyols having number average molecular weights of 400 to 8,000 g / mol, preferably 400 to 6,000 g / mol and particularly preferably 600 to 3,000 g / mol, and OH functionalities of 1.5 to 6, preferably from 1.8 to 3, with particular preference 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 non-ionic hydrophilizing agents,

B) the subsequent reaction of all or some of the free NCO groups thereof

B1) optionally with amino functional compounds having molecular weights of 32 to 400 g / mol and / or

B2) isocyanate reactive hydrophilizing agents, preferably aminofunctional, anionic

or potentially anionic

with chain extension and dispersion of the resulting prepolymers before, during or after step B), into which any potentially ionic group present in the ionic form is converted by partial or complete reaction with a neutralizer.

To achieve an anionic hydrophilization, it is necessary to carry out A4) and / or B2) using hydrophilizing agents containing at least one group that is reactive with the NCO groups, such as amino, hydroxyl or thiol groups, and also containing -COO -or -SO3 or -PO32-as anionic groups or the totally or partially protonated acidic forms thereof as potentially anionic groups.

The preferred anionic aqueous dispersions of polyurethane (I) have a low degree of hydrophilic anionic groups, preferably 0.1 to 15 milliequivalents per 100 g of solid resin.

To achieve good sedimentation stability, the number average particle size of the specific polyurethane dispersions is preferably less than 750 nm, with particular preference less than 500 nm and with very particular preference less than 400 nm, determined by laser correlation spectroscopy .

The ratio between the NCO groups in the compounds of component A1) and the reactive groups with NCO, such as amino, hydroxyl or thiol groups, in the compounds of components A1) to A4) during the preparation of the NCO-functional prepolymer is of 1.05 to 3.5, preferably 1.2 to 3.0, particularly preferably 1.3 to 2.5.

The aminofunctional compounds of step B) are employed in an amount such that the ratio of equivalents of amino groups reactive with isocyanate in these compounds to free isocyanate groups in the prepolymer is from 40 to 150%, preferably between 50 and 125% , with particular preference between 60 and 120%.

Suitable aromatic polyisocyanates of component A1) are aromatic, araliphatic, aliphatic or cycloaliphatic polyisocyanates having an NCO functionality of 2, which are known per se by the person skilled in the art.

Examples of suitable polyisocyanates of this type are 1,4-butylenediisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorondiisocyanate (IPDI), 2,2,4-and / or 2,4,4-trimethylhexamethylene diisocyanate, bis (4, Isomeric 4'-isocyanatocyclohexyl) or mixtures thereof with any desired isomeric content, 1, 4-cyclohexylenediisocyanate, 1, 4-phenylenediisocyanate, 2,4-and / or 2,6-toluylene isocyanate, 1, 5-naphthylenediisocyanate, 2.2 '-and / or 2,4'-and / or 4,4'-diphenylmethanediisocyanate, 1,3-y / or 1'4-bis (2-isocyanatoprop-2-yl) benzene (TMXDI), 1,3-bis (isocyanatomethyl) benzene (XDI) and alkyl 2,6-diisocyanatohexanoates (lysine diisocyanates) containing C1-C8 alkyl groups.

In addition to the aforementioned polyisocyanates, it is also possible to use proportionally modified diisocyanates having a structure of uretdione, isocyanurate, urethane, allophanate, biuret, iminooxadiazinedione and / or oxadiazintrione and unmodified polyisocyanates containing more than 2 NCO groups per molecule, for example , 4-isocyanatomethyl octane-1, 8-diisocyanate (nonanotriisocyanate) or triphenylmethane-4,4 ', 4 "triisocyanate.

These are preferably polyisocyanates or mixtures of polyisocyanates of the type mentioned above which contain only aliphatically and / or cycloaliphatically linked isocyanate groups and have an average NCO functionality of the mixture of 2 to 4, preferably 2 to 2.6 and with particular preference of 2 to 2.4.

Particularly preferred in A1) is 1,6-hexamethylene diisocyanate, isophorondiisocyanate, isomeric bis (4,4'isocyanoccyclohexyl) methanes and mixtures thereof.

In A2) polymer polyols having an average molecular weight in Mn number of 400 to 8,000 g / mol, preferably 400 to 6,000 g / mol and particularly preferably 600 to 3,000 g / mol, are used. These preferably have an OH functionality of 1.5 to 6, particularly preferably 1.8 to 3, with very particular preference of 1.9 to 2.1.

Polymer polyols of this type are polyester polyols, polyacrylate polyols, polyurethane polyols, polycarbonate polyols, polyether polyols, polyester polyacrylate polyols, polyurethane polyacrylate polyols, polyurethane polyester polyols polyurethane polyether polyols polyols Polyols and polyester polycarbonate polyols known per se in polyurethane coating technology. They can be used individually or in any desired mixture with each other in A2).

Polyester condensates of this type are polycondensates, known per se, of di- and optionally tri- and tetraols and di- and optionally tri-and tetracarboxylic acids or hydroxycarboxylic acids or lactones. Instead of the free poly (carboxylic acids), it is also possible to use the corresponding polycarboxylic anhydrides or the corresponding lower alcohol polycarboxylates 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, and also 1, 2-propanediol, 1,3-propanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 6-hexanediol isomers, neopentyl glycol or neopentyl glycol hydroxypivalate, in which 1,6-hexanediol and isomers, neopentyl glycol and neopentyl glycol hydroxypivalate are preferred. In addition, it is also possible to employ polyols such as trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethylisocyanurate.

They are dicarboxylic acids that can be used 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, malonic acid, fumaric acid, malonic acid, itonic acid, fumaric acid, malonic acid , suberic acid, 2-methyl succinic acid, 3,3-diethylglutaric acid and / or 2,2-dimethyl succinic acid. The corresponding anhydrides can also be used as a source of acid.

Provided that the average functionality of the polyol is> 2, monocarboxylic acids such as benzoic acid and hexanecarboxylic acid may also be used.

Preferred acids are aliphatic or aromatic acids of the type mentioned above. Particularly preferred are adipic acid, isophthalic acid and optionally trimellitic acid.

They are hydroxycarboxylic acids that can be used simultaneously as participants of the reaction in the preparation of a polyester polyol containing terminal hydroxyl groups, for example, hydroxycaproic acid, hydroxybutyric acid, hydroxidecanoic acid, hydroxystearic acid and the like. Suitable lactones are caprolactone, butyrolactone and homologs. Caprolactone is preferred.

They can also be used in A2) hydroxyl-containing polycarbonates, preferably polycarbonate diols, having average molecular weights in Mn number of 400 to 8,000 g / mol, preferably 600 to 3,000 g / mol. These are obtainable by reacting 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-bishidroxymethylcyclohexane, 2 -methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dipropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols, bisphenol A and lactone modified diols of the type mentioned above.

The polycarbonate diol preferably comprises from 40 to 100% by weight of hexanediol, preferably 1.6hexanediol and / or hexanediol derivatives. Hexanediol derivatives of this type are based on hexanediol and, in addition to terminal OH groups, contain ester or ether groups. Derivatives of this type are obtainable by reacting hexanediol with excess caprolactone or by etherifying hexanediol with itself, giving di- or trihexylene glycol.

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

The hydroxyl-containing polycarbonates preferably have a linear structure.

The polyether polyols can also be used in A2).

Suitable polyether polyols are, for example, polytetramethylene glycol polyethers known per se in polyurethane chemistry, as are obtainable by polymerization of tetrahydrofuran by opening the cationic ring.

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

Suitable initiating molecules that can be employed are all compounds known in the prior art such as, for example, water, butyldiglycol, glycerol, diethylene glycol, trimethylolpropane, propylene glycol, sorbitol, ethylenediamine, triethanolamine and 1,4-butanediol. Preferred starter molecules are water, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol and butyldiglycol.

Particularly preferred embodiments of the polyurethane dispersions (I) comprise, as component A2), a mixture of polycarbonate polyols and polytetramethylene glycol polyols, in which the proportion of polycarbonate polyols in this mixture is from 20 to 80% by weight and the Polytetramethylene glycol polyols ratio is 80 to 20% by weight. A proportion of 30 to 75% by weight of polytetramethylene glycol polyols and a proportion of 25 to 70% by weight of polycarbonate polyols are preferred. Particularly preferred are a proportion of 35 to 70% by weight of polytetramethylene glycol polyols and a proportion of 30 to 65% by weight of polycarbonate polyols, in each case with the condition that the sum of the percentage by weight of polycarbonate polyols and polytetramethylene glycol polyols is 100%, and the proportion of the sum of polycarbonate polyols and polytetramethylene glycol polyether polyols in component A2) is at least 50% by weight, preferably 60% by weight, and particularly preferably at least 70% by weight.

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

In A3) polyols can be used in said 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 desired mixture thereof with each other.

Also suitable are the ester diols in said molecular weight range, such as esters of αhydroxybutyl-ε-hydroxycaproic acid, esters of ω-hydroxyethyl-γ-hydroxybutyric acid, β-hydroxyethyl adipate or β-hydroxyethyl terephthalate.

In addition, monofunctional compounds containing isocyanate reactive hydroxyl can also be used in A3). Examples of monofunctional compounds of this as ethanol, n-butanol, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropilenglicolmonometiléter, dipropilenglicolmonopropiléter, propilenglicolmonobutiléter, dipropilenglicolmonobutiléter, tripropilenglicolmonobutiléter, 2-ethylhexanol, 1-octanol, 1dodecanol and 1-hexadecanol.

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

The anionic or potentially anionic hydrophilizing compounds of component A4) are understood to mean all compounds containing at least one isocyanate reactive group, such as a hydroxyl group, and at

-

M +

less a functionality such as, for example, -COO-M +, -SO3, -PO (O-M +) 2, in which M + is, for example, a metal cation, H, NH4 +, NHR3 +, in which R can be in each case a C1-C12 alkyl, C5-C6 cycloalkyl and / or C2-C4 hydroxyalkyl radical, which enters into a pH-dependent dissociation equilibrium with the interaction with the aqueous medium and can thus be negatively charged or neutral. They are anionic hydrophilizing compounds

or potentially suitable anionic mono- and dihydroxycarboxylic acids, mono- and dihydroxysulfonic acids and mono- and dihydroxyphosphonic acids and salts thereof. Examples of anionic or potentially anionic hydrophilizing agents of this type are dimethylolpropionic acid, dimethylolbutyric acid, hydroxypivalic acid, malic acid, citric acid, glycolic acid, lactic acid and the propoxylated adduct of 2-butenediol and NaHSO3, as described in DE -A 2,446,440, pages 5-9, formulas I-III. Preferred anionic or potentially anionic hydrophilizing agents of component A4) are those of the type mentioned above which contain carboxylate or carboxylic acid groups and / or sulfonate groups.

Particularly preferred anionic or potentially ionic hydrophilizing agents are A4) those which contain carboxylate or carboxylic acid groups such as ionic or potentially ionic groups, such as dimethylolpropionic acid, dimethylolbutyric acid and hydroxyprovinic acid, or salts thereof.

Suitable non-ionic hydrophilic compounds of component A4) are, for example, polyoxyalkylene ethers containing at least one hydroxyl or amino group, preferably at least one hydroxyl group.

Examples are monohydroxy-functional poly (alkylene oxide) -polyether alcohols containing a statistical average of 5 to 70, preferably 7 to 55, units of ethylene oxide per molecule, as they are accessible in a known manner per se by alkoxylation of molecules suitable initiators (for example, in "Ullmanns Encyclopadie der technischen Chemie [Ullmann's Encyclopedia of Industrial Chemistry]", 4th edition, volume 19, Verlag Chemie, Weinheim, p. 31-38).

These are pure poly (ethylene oxide) -ethers or poly (alkylene oxide) -mixed ethers containing at least 30 mol%, preferably at least 40 mol%, based on all alkylene oxide units present , of ethylene oxide units.

Particularly preferred nonionic compounds are poly (alkylene oxides) -mixed monofunctional polyethers containing 40 to 100 mol% of ethylene oxide units and 0 to 60 mol% of propylene oxide units.

Suitable initiating molecules for non-ionic hydrophilizing agents of this type are saturated monoalcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, isomeric pentanoles, hexanols, octanoles and nonanols, n-decanol, n-dodecanol, n-tetradecanol, n-hexadecanol, noctadecanol, cyclohexanol, isomeric methylcyclohexanols or hydroxymethylcyclohexane, 3-ethyl-3-hydroxymethylxetane

or tetrahydrofurfuryl alcohol, diethylene glycol monoalkyl ethers such as, for example, diethylene glycol monobutyl ether, unsaturated alcohols such as allyl alcohol, 1,1-dimethylalkyl alcohol or oleyl alcohol, aromatic alcohols such as phenol, isomeric cresols or methoxyphenols, araliphatic alcohols such as benzyl alcohol 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-1-piperidine . Preferred starter molecules are saturated monoalcohols of the type mentioned above. Particularly preferred is diethylene glycol monobutyl ether or n-butanol as the initiating molecule.

They are suitable alkylene oxides for the alkoxylation reaction, in particular ethylene oxide and propylene oxide, which can be used in any desired sequence or also as a mixture in the alkoxylation reaction.

As component B1) di- or polyamines such as 1'2-ethylenediamine, 1,2- and 1'3-diaminopropane, 1'4-diaminobutane, 1'6-diaminohexane, isophorondiamine, isomeric mixture of 2,2, 4-and 2,4,4-trimethylhexamethylene diamine, 2-methylpentamethylenediamine, diethylenetriamine, triaminononane, 1,3-y 1-4-xylylenediamine, α, α, α ', α'-tetramethyl-1,3-y -1‚4- xylylenediamine and 4,4-diaminodicyclohexylmethane and / or dimethylethylenediamine. It is also possible to use hydrazine or hydrazides, such as adipohydrazide. Isoforondiamine, 1'2-ethylenediamine, 1'4diaminobutane, hydrazine and diethylenetriamine are preferred.

In addition, compounds which, in addition to a primary amino group, also contain secondary amino groups or, in addition to an amino group (primary or secondary) also contain OH groups, can also be used as component B1. Examples of the same primary / secondary amines are such as diethanolamine, 3-amino1-methylaminopropane, 3-amino-1-ethylaminopropane, 3-amino-1-cyclohexylaminopropane, 3-amino-1-methylaminobutane, alkanolamines such as N-aminoethyl ethanolamine, ethanolamine, 3-aminopropanol and neopentanolamine.

In addition, monofunctional isocyanate reactive amino compounds such as, for example, methylamine, ethylamine, propylamine, butylamine, octylamine, laurylamine, stearylamine, isononyloxypropylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, N-methylaminopropylamine ) aminopropylamine, morpholine, piperidine or suitable substituted derivatives thereof, amidoamides formed by diprimary amines and monocarboxylic acids, monocetyles of diprimary amines and primary / tertiary amines such as N, N-dimethylaminopropylamine.

Preferred compounds of component B1) are 1,2-ethylenediamine, 1,4-diaminobutane and isophorondiamine.

The anionic or potentially anionic hydrophilizing compounds of component B2) are understood to mean all compounds containing at least one isocyanate reactive group, preferably an amino group, and

-

M +

at least one functionality such as, for example, -COO-M +, -SO3, -PO (O-M +) 2, in which M + is, for example, a metal cation, H, NH4 +, NHR3 +, in which R can be in each case a C1-C12 alkyl, C5-C6 cycloalkyl and / or C2-C4 hydroxyalkyl radical, which enters into a pH dependent dissociation equilibrium with the interaction with the aqueous medium and can thus be negatively charged or neutral.

Suitable anionic or potentially anionic hydrophilizing compounds are mono- and diaminocarboxylic acids, mono- and diaminosulfonic acids and mono- and diaminophosphonic acids and salts thereof. Examples of such anionic or potentially anionic hydrophilizing agents are N- (2-aminoethyl) -β-alanine, 2- (2-aminoethylamino) ethanesulfonic acid, ethylenediaminopropylsulfonic acid or ethylenediaminobutyl sulfonic acid, 1,2

or 1,3-propylenediamino-β-ethylsulfonic acid, glycine, alanine, taurine, lysine, 3,5-diaminobenzoic acid and the product of the reaction of addition of IPDA and acrylic acid (EP-A 0.916.647, Example 1) . In addition, cyclohexylaminopropanesulfonic acid (CAPA), which is known from WO-A 01/88006, can be used as an anionic or potentially anionic hydrophilizing agent.

Preferred anionic or potentially anionic hydrophilizing agents of component B2) are those of the type mentioned above which contain carboxylate or carboxylic acid groups and / or sulfonate groups, such as N- (2-aminoethyl) -3-alanine salts, of acid 2- (2-Aminoethylamino) ethanesulfonic acid or the product of the reaction of addition of IPDA and acrylic acid (EP-A 0.916.647, Example 1).

Hydrophilization can also be carried out using mixtures of anionic or potentially anionic hydrophilizing agents and non-ionic hydrophilizing agents.

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

5 to 40% by weight of component A1),

55 to 90% by weight of A2),

0.5 to 20% by weight of the sum of components A3) and B1),

0.1 to 25% by weight of the sum of components A4) and B2), in which 0.1 to 5% by weight of anionic or potentially anionic hydrophilizing agents of A4) and / or B2) are used, based on the total quantities of components A1) to A4) and B1) to B2).

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

5 to 35% by weight of component A1),

60 to 90% by weight of A2),

0.5 to 15% by weight of the sum of components A3) and B1),

0.1 to 15% by weight of the sum of components A4) and B2), in which 0.2 to 4% by weight of anionic or potentially anionic hydrophilizing agents of A4) and / or B2) are used, based on the total quantities of components A1) to A4) and B1) to B2).

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

10 to 30% by weight of component A1),

65 to 85% by weight of A2),

0.5 to 14% by weight of the sum of components A3) and B1),

0.1 to 13.5% by weight of the sum of components A4) and B2), in which 0.5 to 3.0% by weight of anionic or potentially anionic hydrophilizing agents of A4) and / or B2 are used ), based on the total quantities of components A1) to A4) and B1) to B2).

The preparation of the dispersions of anionic hydrophilized polyurethane (I) can be carried out in one or more stages in a homogeneous or multistage reaction, some in dispersed phase. After complete or partial polyaddition of A1) to A4), a dispersion, emulsification or dissolution stage is carried out. If desired, further polyaddition or modification of the dispersed phase is carried out.

All processes known in the prior art such as, for example, the prepolymer mixing process, the acetone process or the melt dispersion process, can be used herein. The procedure with acetone is preferably used.

For the preparation by the acetone process, all or some of the constituents A2) to A4) and the polyisocyanate component A1) are usually initially introduced for the preparation of an isocyanatofunctional polyurethane prepolymer and optionally diluted with a solvent that is miscible with water, but inert for isocyanate groups, and heated to temperatures in the range of 50 to 120 ° C. To accelerate the isocyanate addition reaction, catalysts known in polyurethane chemistry can be employed.

Suitable solvents are conventional ketofunctional aliphatic solvents such as acetone and 2butanone, which can be added not only at the beginning of the preparation, but, if desired, can also be partially added later. Acetone and 2-butanone are preferred.

Other solvents such as xylene, toluene, cyclohexane, butyl acetate, methoxypropyl acetate, N-methylpyrrolidone, N-ethylpyrrolidone, solvents containing ether or ester units may be used and separated by total or partial distillation or, in the case of N-methylpyrrolidone or N-ethylpyrrolidone, left completely in the dispersion. However, preferably other solvents are not used apart from conventional ketofunctional aliphatic solvents.

Subsequently, any constituent from A1) to A4) is introduced which has not already been added at the beginning of the reaction.

In the preparation of the polyurethane prepolymer from A1) to A4), the molar ratio of isocyanate groups to isocyanate reactive groups is 1.05 to 3.5, preferably 1.2 to 3.0, particularly preferably from 1.3 to 2.5.

The conversion of components A1) to A4) in the prepolymer is carried out partially or totally, but preferably totally. Thus, polyurethane prepolymers containing free isocyanate groups in solid state or in solution are obtained.

In the neutralization step for the partial or complete conversion of potentially anionic groups into anionic groups, bases such as tertiary amines are used, for example trialkylamines having 1 to 12 C atoms, preferably 1 to 6 C atoms, with Particular preference of 2 to 3 C atoms, in each alkyl radical or alkali metal bases, such as the corresponding hydroxides.

Examples thereof are trimethylamine, triethylamine, methyldiethylamine, tripropylamine, N-methylmorpholine, methyldiisopropylamine, ethyldiisopropylamine and diisopropylethylamine. Alkyl radicals may also carry, for example, hydroxyl groups, such as dialkylmonoalkanolamines, alkyl dialyanolamines and trialkanolamines. The neutralizers that can be employed, if desired, are also inorganic bases such as aqueous ammonia solution or sodium hydroxide or potassium hydroxide.

Ammonia, triethylamine, triethanolamine, dimethylethanolamine or diisopropylethylamine are preferred, as well as hydroxide

sodium and potassium hydroxide, with particular preference sodium hydroxide and potassium hydroxide.

The molar amount of bases is 50 to 125 mol%, preferably between 70 and 100 mol% of the molar amount of the acid groups to be neutralized. The neutralization can also be carried out simultaneously to the dispersion if the dispersion water already comprises the neutralizer.

In a further process step, the resulting prepolymer is subsequently dissolved, if this has not already taken place or has only partly taken place, with the help of aliphatic ketones such as acetone or 2-butanone.

In the chain extension of step B), NH2-and / or NH-functional components are reacted partially or totally with the remaining isocyanate groups of the prepolymer. The chain extension / termination is preferably carried out before dispersion in water.

For chain termination, amines B1) are commonly used which contain 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, amidoamines formed by diprimary amines and monocarboxylic acids, monocetyles of diprimary amines, primary / tertiary amines such as N, N-dimethylaminopropylamine.

If partial or complete chain extension is carried out using anionic or potentially anionic hydrophilizing agents corresponding to the definition of B2) containing NH2 or NH groups, the chain extension of the prepolymers is preferably carried out before dispersion.

The amino components B1) and B2) can optionally be used in dilute form in water or solvent in the process according to the invention, individually or in mixtures, any addition sequence being in principle possible.

If water or organic solvents are used simultaneously as diluents, the diluent content in the component used in B) for chain extension is preferably 70 to 95% by weight.

The dispersion is preferably carried out after the chain extension. To this end, the dissolved and extended chain polyurethane polymer is introduced into the dispersion water, optionally with high shear such as, for example, with vigorous stirring, or conversely, the dispersion water is stirred in the polymer solutions extended chain polyurethane. Preferably, the water is added to the dissolved extended chain polyurethane polymer.

The solvent still present in the dispersions after the dispersion step is usually subsequently removed by distillation. It is also possible to withdraw during dispersion.

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

The pH of the polyurethane dispersions (I) that are essential for the invention is normally less than 9.0, preferably less than 8.5, with particular preference less than 8.0 and with very particular preference of 6.0 to 7.5.

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

In a further preferred embodiment, dispersion B also comprises coagulants (II) in addition to anionically hydrophilized polyurethane.

The coagulants (II) that can be used in the compositions are all organic compounds containing at least two cationic groups, preferably all prior art cationic flocculants and precipitants, such as cationic homopolymers or copolymers of poly [acrylate salts of 2 - (N, N, N-trimethylamino) ethyl], of polyethyleneimine, of poly [N- (dimethylaminomethyl) acrylamide], of substituted acrylamides, of substituted methacrylamides, of N-vinylformamide, of N-vinylacetamide, of N-vinylimidazole, of 2 -vinylpyridine or 4vinylpyridine.

Preferred coagulants (II) are cationic acrylamide copolymers containing structural units of general formula (2), particularly preferably cationic acrylamide copolymers containing structural units of formula (1) and those of general formula (2):

Formula (1) Formula (2)

in which

R is C = O, -COO (CH2) 2-or -COO (CH2) 3-y

X-is a halide ion, preferably chloride.

The cationic coagulant (II) used is in particular a polymer of this type having a number average molecular weight of 500,000 to 50,000,000 g / mol.

Coagulants (II) of this type are marketed, for example, under the trade name Praestol® (Degussa Stockhausen, Krefeld, Germany) as sewage sludge flocculants. Preferred coagulants of the Praestol® type are: Praestol® K111L, K122L, K133L, BC 270L, K 144L, K 166L, BC 55L, 185K, 187K, 190K, K222L, K232L, K233L, K234L, K255L, K332L, K333L, K334L, K334L, K334L E 125, E 150 and mixtures thereof. Praestol® 185K, 187K and 190K, and mixtures thereof are very particularly preferred coagulants.

The dispersion B preferably comprises at least one pigment.

The manner in which precipitation is achieved in or on the textile substrate depends largely on the chemical composition of the dispersion B used in accordance with the invention and, in particular, on the type of coagulant, if present. For example, precipitation can be carried out by evaporation coagulation or by coagulation by salts, acids or electrolytes.

In general, precipitation is achieved by an increase in temperature. For example, the textile substrate can be subjected to a brief heat treatment with steam, for example at 100-110 ° C, for 1 to 10 seconds. This is particularly preferred if ammonium salts are used as a coagulant. If, on the other hand, the acid generating chemicals mentioned above are used as coagulants, precipitation is preferably carried out as described in US 5,916,636, US 5,968,597, US 5,952,413 and US 6,040. 393

Alternatively, coagulation is caused by immersion in a saline solution. Preferably, coagulation is carried out using an inorganic salt selected from the group consisting of alkali metal salts and alkaline earth metal salts. The inorganic salt is, with particular preference, a salt selected from the group consisting of alkali metal halides, alkali metal nitrates, alkali metal phosphates, alkali metal sulfates, alkali metal carbonates, alkali metal hydrogen carbonates, metal halides alkaline earth metals, alkaline earth metal phosphates, alkaline earth metal nitrates, alkaline earth metal sulfates, alkaline earth metal carbonates and alkaline earth metal hydrogen carbonates. Inorganic salt is, with very particular preference, sodium chloride, potassium chloride, sodium sulfate, sodium carbonate, potassium sulfate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, magnesium chloride, magnesium sulfate, calcium chloride or calcium sulfate. The inorganic salt is, even more preferably, calcium chloride

or magnesium chloride.

Preferably, the inorganic salt is present in the saline solution in an amount of 1 to 25% by weight, particularly preferably in an amount of 1 to 15% by weight, with very particular preference in an amount of 1 to 10% by weight. , based on the total amount of the saline solution.

After precipitation in step c), if necessary additional steps are carried out, such as drying or condensation.

The textile substrate used is preferably a woven fabric, a knitted fabric or a nonwoven material based on natural and / or synthetic fibers. The textile substrate is, with particular preference, a nonwoven material (nonwoven material of cut fiber, nonwoven microfiber material or the like).

The textile substrate may preferably consist of polyester fibers, nylon (6 or 6.6), cotton, polyester / cotton combinations, wool, ramie, Spandex, glass, thermoplastic polyurethane (PUT), thermoplastic olefins (OTP) or similar. The textile substrate may have a bonded / mesh type construction, be woven or not woven.

The textile substrate can be treated with dyes, dyes, pigments, UV absorbers, plasticizers, dirt redeposition agents, lubricants, antioxidants, flame inhibitors, rheological agents and the like, before or after coating, but it is preferred that said Additions are made before coating.

If a defined nonwoven fabric is impregnated with an elastomeric polymer and coagulated and a normal tinting process is subsequently carried out, a synthetic suede type leather having good color development properties is obtained.

Therefore, the present invention further relates to a coated textile material, preferably synthetic leather, obtained by the process according to the invention.

Examples

The dispersion A has the following composition: Ca (NO3) 2 80 pep Methylcellulose 0.4 pep Water 920 pep The dispersion B1 for saline coagulation has the following composition: Impranil 1380 1,000 pep Water 5,000 pep The procedure for the preparation of the coated textile material using saline coagulation is described in Figure

one.

The B2 dispersion for thermal coagulation has the following composition:

Impranil DLU 100 pep

WS 20 Pep Coagulant

Emulvin WA 20 pep

5000 pep water

The process for the preparation of the coated textile material using thermal coagulation is described in Figure 2.

The substrates that underwent the procedure without contacting dispersion A as described had a very hard and rigid feel. In contrast, the substrates that were treated according to the invention exhibited a pleasantly smooth and round touch. In the subsequent coating of the resulting substrates, considerable differences were also revealed between the substrates treated with the dispersion A and the untreated substrates, such that the fall of the folds (folding) appeared angular and / or with bubbles in the case of the untreated coagulant. The substrate treated according to the invention exhibited a round, optically perfect folding.

Claims (10)

1. Production process of coated textile materials, comprising at least the steps of a) contacting a textile substrate with an aqueous dispersion A comprising at least one inorganic salt and at least one modified cellulose, 5 b) contacting a textile substrate with an aqueous dispersion B comprising polyurethane and c) precipitating the polyurethane in or on the textile substrate.

2.

Process according to claim 1, wherein the inorganic salt is a salt selected from the group consisting of alkali metal salts and alkaline earth metal salts.

3.

Process according to claim 2, wherein the alkali metal salt is a selected salt.

10 of the group consisting of alkali metal halides, alkali metal nitrates, alkali metal phosphates, alkali metal sulfates, alkali metal carbonates and alkali metal hydrogen carbonates. 4. The method according to claim 2, wherein the alkaline earth metal salt is a salt selected from the group consisting of alkaline earth metal halides, alkaline earth metal nitrates, alkaline earth metal phosphates, alkaline earth metal sulfates, metal carbonates alkaline earth e 15 alkaline earth metal hydrogen carbonates.

5.

Process according to claim 1, wherein the inorganic salt is present in dispersion A in an amount of 0.01 to 25% by weight, based on the total amount of dispersion A.

6.

Process according to claim 1, wherein the modified cellulose is a selected compound

from the group consisting of methyl cellulose, ethyl cellulose, propyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, carboxy methyl cellulose and carboxypropyl cellulose.

7.

 Process according to claim 1, wherein the modified cellulose is present in dispersion A in an amount of 10 ppm at 5% by weight, based on the total amount of dispersion A.

8.

Method according to claim 1, characterized in that the textile substrate used is a woven fabric, a knitted fabric or a nonwoven material based on natural and / or synthetic fibers.

Method according to claim 1, characterized in that the polyurethane is precipitated in step c) in a bath containing water or with the use of a temperature in the range of 80 to 120 ° C.

10.

Coated textile material obtainable by a process according to claims 1 to 9.

eleven.

Coated textile material according to claim 10, characterized in that the coated textile material is synthetic leather.