JP5730988B2 - Textile coating method - Google Patents

Description

  The present invention relates to a process for producing a coated fabric, wherein the fabric 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 by coating a fabric with a resin has been known for some time. In particular, synthetic leather is used as material for shoe uppers, clothing, heel making materials or in the upholstery field, for example. In addition to other resins (eg PVC), the main coating material used in the present invention is polyurethane. The generally known principle of fabric coating with polyurethane is described in W. Schroeer, Textilveredlung “Textile Finishing”, 1987, 22 (12), 459-467. Furthermore, a description of the agglomeration process can be found in “New Materials Permeable to Water Vapor”, Harro Traeubel, Springer Verlag, Berlin, Heidelberg, New York, 1999, ISBN 3-540-64946-8, pages 42-63.

  The main methods used in the production of synthetic leather are the direct coating method, the transfer coating method (indirect coating) and the agglomeration (wetting) method. In contrast to the direct method, in the transfer method the coating is later applied to a temporary support with a laminating step, where the coating is combined with the textile substrate and separated from the temporary support (release paper). Applied. The transfer method is preferably used for textile substrates that do not allow high tensile stresses in the coating, or particularly for rough fabrics that are not dense.

  In the agglomeration method, the textile substrate is usually coated with a DMF solution containing polyurethane. In the second step, the coated substrate is passed through a DMF / water bath with a progressively increasing proportion of water. The deposition of polyurethane and the formation of a porous coating occurs here. Here, the fact that DMF and water have excellent miscibility and DMF and water function as a solvent / non-solvent pair for polyurethane is utilized. Agglomerated polyurethane coatings have a relatively good respiratory activity and leather feel and are therefore used especially for high quality synthetic leather. The basic principle of the agglomeration method is based on the use of a suitable solvent / non-solvent pair for the polyurethane. A great advantage of the agglomeration method is that it is possible to obtain a porous breath-active synthetic leather with an excellent leather feel. For example, the synthetic leather brands Clarino (R) and Alcantara (R). The disadvantage of the agglomeration method is that it requires the use of large amounts of DMF as the organic solvent. During manufacturing, further design measures must be taken to minimize employee exposure to DMF emissions, which means a significant cost increase compared to a simple process. Furthermore, processing or work-up of large amounts of DMF / water mixture is required. This is a problem because water and DMF form an azeotrope and can therefore only be separated by distillation with high effort.

  Accordingly, one object of the present invention is to provide a textile substrate that does not require the use of a toxicologically unacceptable solvent (for example, DMF) and can provide a coated fabric having good characteristics (for example, a good feel). It was to develop a coating method.

This task is at least
(A) contacting the textile substrate with an aqueous dispersion A comprising at least one inorganic salt and at least one modified cellulose;
(B) achieved by a method for producing a coated fabric comprising the step of bringing the fabric substrate into contact with an aqueous dispersion B containing polyurethane, and (c) the step of depositing polyurethane in or on the fabric substrate. be able to.

A method for preparing a coated fabric using a salt coagulant. A method for preparing a coated fabric using a heat coagulant.

  In step (a), the 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 consisting of alkali metal salts and alkaline earth metal salts. The inorganic salt is particularly preferably an alkali metal halide, alkali metal phosphate, alkali metal nitrate, alkali metal sulfate, alkali metal carbonate, alkali metal bicarbonate, alkaline earth metal halide, alkaline earth metal nitrate. A salt selected from the group consisting of alkaline earth metal phosphates, alkaline earth metal sulfates, alkaline earth metal carbonates and alkaline earth metal bicarbonates. The inorganic salt is particularly preferably sodium chloride, potassium chloride, sodium sulfate, sodium carbonate, potassium sulfate, potassium carbonate, sodium hydrogen carbonate, magnesium chloride, magnesium sulfate, magnesium nitrate, calcium chloride, calcium nitrate or calcium sulfate. More preferably, the inorganic salt is calcium nitrate, magnesium nitrate, calcium chloride or magnesium chloride.

  The inorganic salt is preferably 0.01 to 25% by weight, particularly preferably 0.5 to 15% by weight, particularly preferably 0.5 to 10% by weight, based on the total amount of the dispersion A. In dispersion A.

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

  The chemically modified cellulose is particularly preferably a compound selected from the group consisting of methylcellulose, ethylcellulose, propylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxymethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, carboxyethylcellulose and carboxypropylcellulose.

  The chemically modified cellulose is particularly preferably methylcellulose or ethylcellulose.

  The modified cellulose is preferably dispersed A in an amount of 10 ppm to 5% by weight, particularly preferably in an amount of 100 ppm to 3% by weight, particularly preferably in an amount of 400 ppm to 1.5% by weight, based on the total amount of Dispersion A. Present in.

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

  Preferably, after contacting with the dispersion A, in order to remove an excessive amount of the dispersion A, the fabric substrate is passed through a squeezing machine composed of two rollers. In the present invention, the squeezer preferably has an amount of 60 to 180% by weight, particularly preferably, based on the weight per unit area of the (solution absorption) substrate before bringing the dispersion B containing polyurethane into contact with the substrate. Should be set so that the dispersion A remains in the textile substrate in an amount of 70 to 140% by weight, particularly preferably in an amount of 80 to 120% by weight. Prior to contacting the substrate with the dispersion B comprising polyurethane, the woven substrate is preferably dried using air, infrared or a hot cylinder, preferably for 2 to 10 minutes, particularly preferably for 1 to 5 minutes.

  The polyurethane present in dispersion B is not limited as long as it is soluble in water, and the term “polyurethane” also includes polyurethane-polyurea. Regarding the polyurethane (PUR) dispersion and the production method thereof, refer to Rosthauser & Nacht-kamp, “Waterborne Polyurethanes, Advances in Urethane Science and Technology”, Vol. 10, pp. 121-162 (1987). Suitable dispersions are also described, for example, in “Kunststoff-handbuch” [Plastics Handbook], volume 7, second edition, Hauser, pages 24-26.

The constituents of dispersion B used in the present invention may be the following components:
(1) Organic di- and / or polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 2-methylpentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate (THDI), dodecane methylene diisocyanate, 1,4-diisocyanatocyclohexane, 3-isocyanatomethyl-3,3,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate = IPDI), 4,4′-diisocyanatodicyclohexyl methane (Desmodur® W), 4,4′-diisocyanato-3,3′-dimethyldicyclohexylmethane, 4,4′-diisocyanato-2,2-dicyclohexylpropane, 1,4-diisocyanatobenzene, 2, 4- or 2,6-diisocyanatotoluene or an isomer mixture thereof, 4,4′-, 2,4- or 2,2′-diisocyanatodiphenylmethane or an isomer mixture thereof, 4,4-, 2,4′- or 2,2′-diisocyanato-2,2-diphenylpropane-p-xylene diisocyanate and α, α, α ′, α′-tetramethyl-m- or -p-xylene diisocyanate (TMXDI) and A mixture composed of these compounds. A small amount of the diisocyanate trimer, urethane, burette, allophanate or uretdione can be used for modification. MDI, Desmodur W, HDI and / or IPDI are particularly preferred.

  (2) A polyhydroxy compound having 1 to 8, preferably 1.7 to 3.5 hydroxy groups in one molecule and an (average) molecular weight of up to 16,000, preferably up to 4000. Specific low molecular weight polyhydroxy compounds in each case, such as ethylene glycol, 1,2-, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane , Glycerin, 1 hydrazine + 2 propylene glycol reaction product, and oligomeric or polymeric hydroxy compounds having a molecular weight of 350-10,000, preferably 840-3000 may be considered.

  Relatively high molecular weight hydroxy compounds include hydroxy polyesters, hydroxy polyethers, hydroxy polythioethers, hydroxy polyacetates, hydroxy polycarbonates and / or hydroxy polyester amides known per se in polyurethane chemistry, with an average of 350-4000 Those having a molecular weight are preferred, and those having an average molecular weight of 840 to 3000 are particularly preferred. Hydroxy polycarbonate and / or hydroxy polyether are particularly preferred. When these are used, aggregates with specific stability against hydrolysis can be prepared.

(3a) An ionic or potentially ionic hydrophilizing agent comprising an acid group and / or an acid group in salt form and at least one isocyanate-reactive group (eg OH group or NH ₂ group). For example, ethylenediamine-β-ethylsulfonic acid (AAS salt solution), dimethylolpropionic acid (DMPA), dimethylolbutyric acid, sodium salt of hydroxypivalic acid or 1 mol of diamine (preferably isophoronediamine) and 1 mol of α, β -Adducts of unsaturated carboxylic acids (preferably acrylic acid).

  (3b) A nonionic hydrophilizing agent in the form of monofunctional and / or bifunctional polyethylene oxide or polyethylene-propylene oxide alcohol having a molecular weight of 300 to 5000. Particular preference is given to monohydroxy-functional ethylene oxide / propylene oxide polyethers based on n-butanol having 35 to 85% by weight of ethylene oxide units and a molecular weight of 900 to 2500. A content of nonionic hydrophilizing agent of at least 3% by weight, in particular at least 6% by weight, is preferred.

(4) Blocking agents for isocyanate groups, such as oximes (acetone oxime, butanone oxime or cyclohexanone oxime), secondary amines (diisopropylamine, dicyclohexylamine), NH-acidic heterocyclic substances (3,5-dimethylpyrazole, imidazole, 1,2,4-triazole), CH-acidic ester ( _C1-4 alkyl malonate, acetate) or lactam (ε-caprolactam). Butanone oxime, diisopropylamine and 1,2,4-triazole are particularly preferred.

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

  (6) Polyamine crosslinking agent. These are preferably aliphatic or cycloaliphatic diamines, but trifunctional or polyfunctional polyamines can also be used if desired to achieve specific properties. In general, polyamines having additional functional groups (eg OH groups) can also be used. Polyamine crosslinkers that are not incorporated into the polymer backbone at normal or slight elevated ambient temperatures (eg, 20-60 ° C.) are mixed during or immediately after the preparation of the reactive dispersion. Suitable aliphatic polyamines are ethylenediamine, 1,2- and 1,3-propylenediamine, 1,4-tetramethylenediamine, 1,6-hexamethylenediamine, 2,2,4- and 2,4,4- An isomeric mixture of trimethylhexamethylenediamine, 2-methylpentamethylenediamine and diethylenetriamine.

  In another preferred embodiment, dispersion B comprises at least one coagulant in addition to the polyurethane. The coagulant is a salt or acid, for example, an ammonium salt of an organic acid that causes aggregation of the polyurethane under certain conditions (eg, under certain temperatures). These substances include acid producing chemicals (ie, substances that are not acids at room temperature but become acid when heated). Specific examples of such compounds include ethylene glycol diacetate, ethylene glycol formate, diethylene glycol formate, triethyl citrate, monostearyl citrate and organic acid esters.

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

The polyurethane present in dispersion B is an anionic and / or non-ionic hydrophilized polyurethane,
(A) (A1) Organic polyisocyanate (A2) 400-8000 g / mol, preferably 400-6000 g / mol, particularly preferably 600-3000 g / mol, and number average molecular weight of 1.5-6, preferably Is a polymer polyol having an OH number of 1.8 to 3, particularly preferably 1.9 to 2.1 (A3) optionally a hydroxy-functional compound having a molecular weight of 32 to 400 g / mol, and (A4) Preparing an isocyanate-functional prepolymer from an isocyanate-reactive, anionic or potentially anionic hydrophilizing agent, and / or optionally a nonionic hydrophilizing agent,
(B) followed by all or part of them free NCO groups (B1) optionally an amino-functional compound having a molecular weight of 32 to 400 g / mol, and / or (B2) isocyanate-reactive, preferably Reacts the amino-functional, anionic or potential anionic hydrophilizing agent with the chain extender, disperses the resulting prepolymer in water before, during or after step (B) An ionic group can be obtained by converting to an ionic state by partial or complete reaction with a neutralizing agent.

-COO To achieve anionic hydrophilization comprises at least one NCO-reactive group (e.g. amino, hydroxy or thiol group), as further anionic group ^-, -SO ₃ ^- or _-PO ^{3 2 -,} or it is necessary to perform the (A4) and / or (B2) with hydrophilizing agents containing them fully or partially protonated form as potential anionic groups.

  Preferred aqueous anionic polyurethane dispersion (I) has a low hydrophilicity anionic group, preferably in an amount of 0.1 to 15 milliequivalents relative to 100 g of the solid resin.

  In order to obtain good precipitation stability, the number average particle size of certain polyurethane dispersions is preferably less than 750 nm, particularly preferably less than 500 nm, particularly preferably less than 400 nm (by laser correlation spectroscopy). Measurement).

  During the production of the NCO functional prepolymer, the NCO groups in the compound of component (A1) and the NCO reactive groups in the compounds of components (A2) to (A4) (eg amino groups, hydroxy groups or thiol groups) The ratio is 1.05 to 3.5, preferably 1.2 to 3.0, particularly preferably 1.3 to 2.5.

  In step (B), the amino-functional compound has an equivalent ratio of isocyanate-reactive amino groups in these compounds to free isocyanate groups in the prepolymer of 40 to 150%, preferably 50 to 125%, particularly preferably 60. Use in such an amount that it is ˜120%.

  Suitable polyisocyanates of component (A1) are aromatic, aliphatic aromatic, aliphatic or cycloaliphatic polyisocyanates having an NCO functionality of 2 known per se to those skilled in the art.

Examples of suitable polyisocyanates of this type are 1,4-butylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,2,4- and / or 2,4,4- Trimethylhexamethylene diisocyanate, isomeric bis (4,4'-isocyanatocyclohexyl) methane or mixtures thereof with any desired isomeric material, 1,4-cyclohexylene diisocyanate, 1,4-phenylene diisocyanate, 2,4 -And / or 2,6-tolylene diisocyanate, 1,5-naphthylene diisocyanate, 2,2'- and / or 2,4'- and / or 4,4'-diphenylmethane diisocyanate, 1,3- and / or Or 1,4-bis (2-isocyanatopro-2- Yl) -benzene (TMXDI), 1,3-bis (isocyanatomethyl) benzene (XDI), and C ₁ -C ₈ -alkyl group-containing alkyl 2,6-diisocyanatohexanoate (lysine diisocyanate) .

  In addition to the above polyisocyanates, uretdiones, isocyanurates, urethanes, allophanates, burettes, partially modified diisocyanates having an imino-oxazinedione and / or oxadiazinetrione structure and unmodified having more than 2 NCO groups in one molecule Modified polyisocyanates such as 4-isocyanatomethyloctane, 1,8-diisocyanate (nonane triisocyanate) or triphenylmethane 4,4 ′, 4 ″ -triisocyanate can also be used.

  These preferably contain polyisocyanates or exclusively aliphatic and / or cycloaliphatically bound isocyanate groups and are mixtures of 2 to 4, preferably 2 to 2.6, particularly preferably 2 to 2.4. A mixture of the above type having an average NCO functionality of

  1,6-hexamethylene diisocyanate, isophorone diisocyanate, isomeric bis (4,4'-isocyanatocyclohexyl) methane, and mixtures thereof are particularly preferably used in (A1).

  A polymer polyol having a number average molecular weight (Mn) of 400 to 8000 g / mol, preferably 400 to 6000 g / mol and particularly preferably 600 to 3000 g / mol is used in (A2). These preferably have an OH functionality of 1.5 to 6, particularly preferably 1.8 to 3, particularly preferably 1.9 to 2.1.

  This type of polymer polyol is a polyester polyol, polyacrylate polyol, polyurethane polyol, polycarbonate polyol, polyether polyol, polyester polyacrylate polyol, polyurethane polyacrylate polyol, polyurethane polyester polyol, polyurethane polyether polyol known per se in the polyurethane coating art. Polyurethane polycarbonate polyols and polyester polycarbonate polyols. These can be used alone or in any mixture with one another in (A2).

  Polyester polyols of this kind are polycondensates of diols known per se and optionally triols and tetraols and di-, optionally tri- and tetracarboxylic acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids, the corresponding polycarboxylic anhydrides or polycarboxylates of lower alcohols can also be used 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 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1 1,4-butanediol, 1,6-hexanediol and isomers, neopentyl glycol or neopentyl glycol hydroxypivalate, 1,6-hexanediol and isomers, neopentyl glycol and neopentyl glycol hydroxypivalate preferable. In addition, polyols such as trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethyl isocyanurate can also be used.

  Dicarboxylic acids that can be used 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. Acids, itaconic acid, malonic acid, suberic acid, 2-methylsuccinic acid, 3,3-diethylglutaric acid and / or 2,2-dimethylsuccinic acid. Corresponding anhydrides can also be used as the acid source.

  As long as the average functionality of the esterified polyol is greater than 2, monocarboxylic acids such as benzoic acid and hexanecarboxylic acid can also be used.

  Preferred acids are aliphatic or aromatic acids of the type described above. Particular preference is given to adipic acid, isophthalic acid and optionally trimellitic acid.

  Examples of the hydroxycarboxylic acid that can be used as a reaction component in the preparation of the polyester polyol having a terminal hydroxy group include hydroxycaproic acid, hydroxybutyric acid, hydroxydecanoic acid, and hydroxystearic acid. Suitable lactones are caprolactone, butyrolactone and homologues. Caprolactone is preferred.

  Likewise, hydroxy-containing polycarbonates, preferably polycarbonate diols having a number average molecular weight (Mn) of 400 to 8000 g / mol, preferably 600 to 3000 g / mol, can also be used in (A2). These are obtained by reaction of carboxylic acid derivatives such as diphenyl carbonate, dimethyl carbonate or phosgene with polyols, preferably diols.

  This type of diol includes ethylene glycol, 1,2- and 1,3-propanediol, 1,3- and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol 1,4-bishydroxymethylcyclohexane, 2-methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycol Bisphenol A and the above-mentioned lactone-modified diols.

  The polycarbonate diol preferably comprises 40 to 100% by weight of hexanediol, preferably 1,6-hexanediol and / or hexanediol derivatives. This type of hexanediol derivative is based on hexanediol and contains an ester group or an ether group in addition to the terminal OH group. This type of derivative is obtained by forming dihexylene glycol or trihexylene glycol by reaction of hexanediol with an excess of caprolactone or by etherification of hexanediol with itself.

  Instead of or in addition to pure polycarbonate diol, polyether polycarbonate diol can also be used in (A2).

  The hydroxy-containing polycarbonate preferably has a linear structure.

  Polyether polyols can also be used in (A2).

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

  Likewise suitable polyether polyols are adducts of styrene oxide, ethylene oxide, propylene oxide, butylene oxide and / or epichlorohydrin, known per se, to difunctional or polyfunctional starting molecules. Polyether polyols based on at least partial additions of ethylene oxide to difunctional or polyfunctional starting molecules can also be used as component (A4) (nonionic hydrophilizing agent).

  Suitable starting molecules that can be used are all compounds known in the prior art, for example water, butyl diglycol, glycerol, diethylene glycol, trimethylolpropane, propylene glycol, sorbitol, ethylenediamine, triethanolamine, 1,4- Butanediol. Preferred starting molecules are water, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol and butyl diglycol.

  The polyurethane dispersion (I) of a particularly preferred embodiment comprises as component (A2) a mixture of polycarbonate polyol and polytetramethylene glycol polyol, the proportion of polycarbonate polyol in this mixture being 20 to 80% by weight, The proportion of tetramethylene glycol polyol is 80 to 20% by weight. A proportion of 30-75% by weight of polytetramethylene glycol polyol and a proportion of 25-70% by weight of polycarbonate polyol are preferred. A proportion of 35 to 70% by weight of polytetramethylene glycol polyol and a proportion of 30 to 65% by weight of polycarbonate polyol are particularly preferred. However, in each case, the total weight percent of polycarbonate polyol and polytetramethylene glycol polyol is 100%, and the proportion of polycarbonate polyol and polytetramethylene glycol polyether polyol in component (A2) is at least 50% by weight, preferably Is 60% by weight, particularly preferably 70% by weight.

  The compound of component (A3) has a molecular weight of 62 to 400 g / mol.

  Polyols of the above molecular weight 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 mixtures thereof can be used in (A3).

  Also suitable are ester diols of the above molecular weight range, such as α-hydroxybutyl-ε-hydroxycaproate, ω-hydroxyhexyl-γ-hydroxybutyrate, β-hydroxyethyl adipate or β-hydroxyethyl terephthalate.

  In addition, monofunctional isocyanate-reactive hydroxy-containing compounds can also be used in component (A3). Examples of monofunctional compounds of this type are 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, 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.

Anionic or potentially anionic hydrophilicizing compounds of component (A4) at least one isocyanate-reactive groups (e.g. hydroxy groups) and at least one functional group _{^{(e.g., -COO - M +, -SO 3}} - M ⁺ , —PO (O ⁻ M ⁺ ) ₂ [M ⁺ is, for example, a metal cation, H ⁺ , NH ₄ ⁺ , or NHR ₃ ⁺ , and R is C _{1 to} C ₁₂ alkyl or C _{5 to} C ₆ cycloalkyl, respectively. And / or C ₂ -C ₄ hydroxyalkyl groups]) (which are in a pH-dependent dissociation equilibrium upon interaction with an aqueous medium, thereby producing a negative or neutral charge) It is understood to mean a compound. Suitable anionic or potentially anionic hydrophilizing compounds are mono- and dihydroxy carboxylic acids, mono- and dihydroxy sulfonic acids, and mono- and dihydroxy phosphoric acids, and salts thereof. Examples of this kind of anionic or potentially hydrophilizing agents are dimethylolpropionic acid, dimethylolbutyric acid, hydroxypivalic acid, malic acid, citric acid, glycolic acid, lactic acid and German 2446440, 5-9, formulation A propoxylated adduct of 2-butenediol and NaHSO ₃ as described in I-III. Preferred anionic or potentially hydrophilizing agents for component (A4) are of the above type comprising carboxylate groups or carboxylic acid groups and / or sulfonate groups.

  Particularly preferred anionic or latent hydrophilizing agents for component (A4) are those containing carboxylate or carboxylic acid groups as ionic or latent ionic groups, such as dimethylolpropionic acid, dimethylolbutyric acid and hydroxypivalic acid. Or a salt thereof.

  Suitable nonionic hydrophilizing compounds of component (A4) are, for example, polyoxyalkylene ethers containing at least one hydroxy group or amino group, preferably at least one hydroxy group.

  Examples thereof are monohydroxy-functional polyalkylene oxides containing a statistical average of 5 to 70, preferably 7 to 55, ethylene oxide units per molecule, as obtained in a manner known per se by alkoxylation of suitable starting molecules. Polyethers (eg, Ullmanns Encyclopaedie der technischen Chemie [Ullmann's Encyclopedia of Industrial Chemistry], 4th edition, volume 19, Verlag Chemie, Weinheim, pages 31-38).

  These are either pure polyethylene oxide ethers or mixed polyalkylene oxide ethers containing at least 30 mol%, preferably at least 40 mol% ethylene oxide units, based on the total alkylene oxide units present.

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

  Starting molecules of this type of suitable nonionic hydrophilizing agent include saturated monoalcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, isomeric pentanol, hexanol, Octanol and nonanol, n-decanol, n-dodecanol, n-tetradecanol, n-hexadecanol, n-octadecanol, cyclohexanol, isomeric methylcyclohexanol or hydroxymethylcyclohexane, 3-ethyl-3-hydroxy Methyl oxetane or tetrahydrofurfuryl alcohol, diethylene glycol monoalkyl ether such as diethylene glycol monobutyl ether, unsaturated alcohol such as allyl alcohol, 1,1-dimethyl Allyl alcohol or oleyl alcohol, aromatic alcohols such as phenol, isomeric cresol or methoxyphenol, araliphatic alcohols such as benzyl alcohol, anis alcohol or cinnamyl alcohol, secondary monoamines such as dimethylamine, diethylamine, dipropylamine , Diisopropylamine, dibutylamine, bis (2-ethyl-hexyl) amine, N-methyl- and N-ethylcyclohexylamine or dicyclohexylamine, and heterocyclic secondary amines such as morpholine, pyrrolidine, piperidine or 1H-pyrazole It is. Preferred starting molecules are saturated monoalcohols of the kind described above. Diethylene glycol monobutyl ether or n-butanol is particularly preferred as the starting molecule.

  Suitable alkylene oxides for the alkoxylation reaction are in particular ethylene oxide and propylene oxide, which can be used in any desired order or in a mixture in the alkoxylation reaction.

  Di- or polyamines such as 1,2-ethylenediamine, 1,2- and 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, isophoronediamine, 2,2,4- and 2, Isomeric mixture of 4,4-trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylenetriamine, triaminononane, 1,3- and 1,4-xylylenediamine, α, α, α ′, α′-tetra Methyl-1,3- and 1,4-xylylenediamine and 4,4-diaminodicyclohexylmethane and / or dimethylethylenediamine can be used as component (B1). Similarly, hydrazine or hydrazide, such as adipohydrazide, can be used. Isophoronediamine, 1,2-ethylenediamine, 1,4-diaminobutane, hydrazine and diethylenetriamine are preferred.

  Furthermore, a compound containing a secondary amino group in addition to a primary amino group, or containing an OH group in addition to an amino group (primary or secondary) can also be used as the component (B1). 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-amino-ethylethanolamine, ethanolamine, 3-aminopropanol, neopentanolamine.

  In addition, monofunctional isocyanate-reactive amino compounds such as methylamine, ethylamine, propylamine, butylamine, octylamine, laurylamine, stearylamine, isononyloxypropylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, N -Amidoamines made from primary diamines and monocarboxylic acids, such as methylaminopropylamine, diethyl (methyl) aminopropylamine, morpholine, piperidine, or suitable substituted derivatives thereof, primary diamine monoketim, primary / Tertiary amines such as N, N-dimethylaminopropylamine can also be used as component (B1).

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

Anionic or potentially anionic hydrophilicizing compounds of component (B2) is at least one isocyanate-reactive group (preferably an amino group) and at least one functional group _{^{(e.g., -COO - M +, -SO 3}} - M ⁺ , —PO (O ⁻ M ⁺ ) ₂ [M ⁺ is, for example, a metal cation, H ⁺ , NH ₄ ⁺ , or NHR ₃ ⁺ , and R is a C _{1 to} C ₁₂ alkyl group or C _{5 to} C _{6, respectively.} Can be cycloalkyl groups and / or C ₂ -C ₄ hydroxyalkyl groups]) (which are in a pH-dependent dissociation equilibrium upon interaction with an aqueous medium, thereby producing a negative or neutral charge). It is understood to mean all compounds comprising.

  Suitable anionic or potentially anionic hydrophilizing compounds are mono- and diaminocarboxylic acids, mono- and diaminosulfonic acids, and mono- and diaminophosphoric acids, and salts thereof. Examples of this type of anionic or potentially hydrophilizing agent are N- (2-aminoethyl) -β-alanine, 2- (2-aminoethylamino) -ethanesulfonic acid, ethylenediaminepropyl- or -butylsulfone. Acid, 1,2- or 1,3-propylenediamine-β-ethylsulfonic acid, glycine, alanine, taurine, lysine, 3,5-diaminobenzoic acid and addition reaction product of IPDA and acrylic acid (EP-A0916647, Example 1). Furthermore, cyclohexylaminopropanesulfonic acid (CAPA) known from WO 01 / 88006A can also be used as an anionic or potentially anionic hydrophilizing agent.

  Preferred anionic or potentially anionic hydrophilizing agents of component (B2) are of the aforementioned type comprising carboxylate groups or carboxylic acid groups and / or sulfonate groups, for example N- (2-aminoethyl) A salt of -β-alanine, a salt of 2- (2-aminoethylamino) ethanesulfonic acid or an addition reaction product of IPDA and acrylic acid (EP-A0916647, Example 1).

  Hydrophilization can also be performed using a mixture of an anionic or latent anionic hydrophilizing agent and a nonionic hydrophilizing agent.

In a preferred embodiment for the preparation of certain polyurethane dispersions, components (A1) to (A4) and (B1) to (B2) are used in the following amounts (individual amounts are always 100% by weight in total): Based on the sum of components (A1) to (A4) and (B1) to (B2),
5 to 40% by weight of component (A1),
55 to 90% by weight of (A2),
A total of 0.5 to 20% by weight of components (A3) and (B1)
A total of 0.1 to 20% by weight of components (A4) and (B2)
A total of 0.1 to 5% by weight of an anionic or potential anionic hydrophilizing agent derived from (A4) and / or (B2) is used.

In a particularly preferred embodiment for the preparation of certain polyurethane dispersions, components (A1) to (A4) and (B1) to (B2) are used in the following amounts (individual amounts are always 100% by weight in total): : Based on the sum of components (A1) to (A4) and (B1) to (B2)
5 to 35% by weight of component (A1),
60 to 90% by weight of (A2),
A total of 0.5 to 15% by weight of components (A3) and (B1)
A total of 0.1 to 15% by weight of components (A4) and (B2)
And a total of 0.2 to 4% by weight of an anionic or potential anionic hydrophilizing agent derived from (A4) and / or (B2) is used.

In a particularly preferred embodiment for the preparation of certain polyurethane dispersions, components (A1) to (A4) and (B1) to (B2) are used in the following amounts (individual amounts are always 100% by weight in total): : Based on the sum of components (A1) to (A4) and (B1) to (B2)
10 to 30% by weight of component (A1),
65 to 85% by weight of (A2),
A total of 0.5 to 14% by weight of components (A3) and (B1)
A total of 0.1 to 13.5% by weight of components (A4) and (B2)
A total of 0.5 to 3.0% by weight of an anionic or potential anionic hydrophilizing agent derived from (A4) and / or (B2) is used.

  The preparation of the anionic hydrophilized polyurethane dispersion (I) may be carried out in a single one or more steps or multi-stage reactions, and may be carried out in the dispersed phase. After complete or partial polyaddition from (A1) to (A4), a dispersion, emulsification or solubilization step is performed. If necessary, further polyaddition or modification is then carried out in the dispersed phase.

  In the present invention, all methods known in the prior art can be used, for example, a prepolymer mixing method, an acetone method, or a melt dispersion method. The acetone method is preferably used.

  Regarding the preparation by the acetone method, in the preparation of an isocyanate functional polyurethane prepolymer, all or part of the components (A2) to (A4) and the polyisocyanate component (A1) are usually added first, and optionally water miscible. However, it is diluted with an isocyanate group inert solvent and heated to a temperature in the range of 50-120 ° C. Known catalysts can be used in polyurethane chemistry to promote the isocyanate addition reaction.

  Suitable solvents are conventional aliphatic keto functional solvents such as acetone, 2-butanone, and the solvent can be added not only at the beginning of the preparation, but also later if necessary. Acetone and 2-butanone are preferred.

  Furthermore, other solvents such as solvents containing xylene, toluene, cyclohexane, butyl acetate, methoxypropyl acetate, N-methylpyrrolidone, N-ethylpyrrolidone, ether or ester units can additionally be used, or completely Alternatively, it can be partially distilled off, and in the case of N-methylpyrrolidone or N-ethylpyrrolidone, it can remain completely in the dispersion. However, preferably no other solvents are used other than conventional aliphatic keto functional solvents.

  Thereafter, (A1) to (A4) which were not added at the initial stage of the reaction are measured.

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

  The conversion of components (A1) to (A4) into a prepolymer is carried out partially or completely, but is preferably carried out completely. Thereby, the polyurethane prepolymer containing a free isocyanate group can be obtained in solid or liquid form.

  In a neutralization step that results in partial or complete conversion of a potential anionic group to an anionic group, a base such as a tertiary amine such as 1 to 12, preferably 1 to 6 in each alkyl group Particularly preferred are trialkylamines or alkali metal bases having 2 to 3 carbon atoms, such as the corresponding hydroxides.

  Examples thereof are trimethylamine, triethylamine, methyldiethylamine, tripropylamine, N-methylmorpholine, methyldiisopropylamine, ethyldiisopropylamine and diisopropylethylamine. As in the case of dialkylmonoalkanolamines, alkyldialkanolamines and trialkanolamines, the alkyl group may have, for example, a hydroxy group. The neutralizing agent which can be used is optionally an inorganic base such as aqueous ammonia solution or sodium hydroxide or potassium hydroxide.

  Ammonia, triethylamine, triethanolamine, dimethylethanolamine or diisopropylethylamine, and sodium hydroxide and potassium hydroxide are preferred, and sodium hydroxide and potassium hydroxide are particularly preferred.

  The molar amount of the base is 50 to 125 mol%, preferably 70 to 100 mol%, of the molar amount of the acid group to be neutralized. If the dispersion water already contains a neutralizing agent, neutralization can be performed simultaneously with the dispersion.

  In a further processing step, the prepolymer obtained thereafter is dissolved with an aliphatic ketone such as acetone or 2-butanone, if not yet dissolved or only partially dissolved.

In the chain extension step (B), NH 2 _- remaining isocyanate groups and moieties and / or NH- functional component of the prepolymer or in complete reaction. Chain extension / chain termination is preferably performed prior to dispersion in water.

  For chain termination, amines containing isocyanate-reactive groups (B1), 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 from primary diamines and monocarboxylic acids, monoketims of primary diamines, primary Primary / tertiary amines such as N, N-dimethylaminopropylamine are used.

If partial or complete chain extension is carried out with an anionic or potentially anionic hydrophilizing agent according to the definition (B2) containing NH ₂ groups or NH groups, preferably the prepolymer chains before dispersion Perform extension.

  Amine components (B1) and (B2) can optionally be used in the process of the present invention, either alone or as a mixture, diluted with water or solvent and can be added in essentially any order.

  When water or an organic solvent is used as a diluent, the diluent content of the chain extender component used in (B) is preferably in the range of 70 to 95% by weight.

  Preferably, dispersion is performed following chain extension. For dispersion, the dissolved and chain-extended polyurethane polymer is introduced into the water for dispersion, if appropriate, for example by substantial shearing such as vigorous stirring, or vice versa. Place in the extended polyurethane polymer solution with stirring. It is preferred to add water to the dissolved and chain extended polyurethane polymer.

  Then, after the dispersion step, the solvent still present in the dispersion is usually removed by distillation. Removal during the dispersion process is also possible.

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

  The pH of the polyurethane dispersion (I) essential to the present invention is typically less than 9.0, preferably less than 8.5, more preferably less than 8.0, and particularly preferably 6.0-7. .5 range.

  The solid content of the polyurethane dispersion (I) is preferably in the range of 40 to 70% by weight, more preferably in the range of 50 to 65% by weight, and particularly preferably in the range of 55 to 65% by weight.

  In another preferred embodiment, dispersion B also contains a coagulant (II) in addition to the anionic hydrophilizing polyurethane.

  The coagulant (II) used in the composition is any organic compound containing at least two cationic groups, preferably cationic flocculants and precipitants known in the prior art, for example of the following substances: It may be a cationic homopolymer or copolymer of a salt: poly [2- (N, N, N-trimethylamino) ethyl acrylate], polyethyleneimine, poly [N- (dimethylaminomethyl) acrylamide], substituted acrylamide, substituted Methacrylamide, N-vinylformamide, N-vinylacetamide, N-vinylimidazole, 2-vinylpyridine, or 4-vinylpyridine.

〔式中、Ｒは、Ｃ＝Ｏ、−ＣＯＯ（ＣＨ_２）_２−、または−ＣＯＯ（ＣＨ_２）_３−であり、Ｘ−は、ハライドイオン、好ましくは塩化物イオンである〕
で示される構造単位を含有するアクリルアミドのカチオン性コポリマーである。 Preferred coagulants (II) are those of general formula (2), particularly preferably of general formulas (1) and (2):

[Wherein R is C═O, —COO (CH ₂ ) ₂ —, or —COO (CH ₂ ) ₃ —, and X— is a halide ion, preferably a chloride ion]
A cationic copolymer of acrylamide containing the structural unit represented by

  The cationic coagulant (II) used particularly preferably has a number average molecular weight in the range of 500,000 to 50,000,000 g / mol.

  This type of coagulant (II) is commercially available, for example, under the trade name Praestol® (Degussa Stockhausen, Krefeld, Germany) as a flocculant for sewage sludge. 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, E125, E150, and mixtures thereof. Praestol® 185K, 187K, 190K and mixtures thereof are very particularly preferred coagulants.

  Dispersion B preferably contains at least one pigment.

  The method of achieving precipitation in or on the textile substrate is highly dependent on the chemical composition of the dispersion B according to the invention used, in particular, if present, the type of coagulant. For example, precipitation can be carried out by evaporation coagulation or salt, acid or electrolyte coagulation.

  In general, precipitation is achieved by increasing temperatures. For example, the fabric substrate can be subjected to a short heat treatment with steam (for example, at 100 to 110 ° C. for 1 to 10 seconds). This heat treatment is particularly preferred when an ammonium salt or organic acid is used as the coagulant. On the other hand, when using the acid producing chemicals described above as the coagulant, precipitation is preferably performed as described in US 5,916,636, US 5,968,597, US 5,952,413 and US 6,040,393. .

  Alternatively, coagulation is performed by immersion in a salt solution. Solidification is preferably performed using an inorganic salt selected from the group consisting of alkali metal salts and alkaline earth metal salts. The inorganic salt is particularly preferably an alkali metal halide, alkali metal nitrate, alkali metal phosphate, alkali metal sulfate, alkali metal carbonate, alkali metal bicarbonate, alkaline earth metal halide, alkaline earth metal. A salt selected from the group consisting of phosphate, alkaline earth metal nitrate, alkaline earth metal sulfate, alkaline earth metal carbonate and alkaline earth metal bicarbonate. The inorganic salt is particularly preferably 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 more preferably calcium chloride or magnesium chloride.

  In the salt solution, the inorganic salt is preferably present in an amount of 1 to 25% by weight, particularly preferably 1 to 15% by weight, particularly preferably 1 to 10% by weight, based on the total amount of the salt solution.

  After the precipitation in step (C), further steps such as drying or concentration are performed as necessary.

  The textile substrate used is preferably a woven, knitted or non-woven fabric based on natural and / or synthetic fibers. Particularly preferred woven base materials are nonwoven fabrics (such as staple fiber nonwoven fabrics and microfiber nonwoven fabrics).

  The textile substrate is preferably a fiber such as polyester, nylon (6 or 6,6), cotton, polyester / cotton mixed fiber, wool, lamin, spandex, glass, thermoplastic polyurethane (TPU), thermoplastic olefin (TPO), etc. Consists of The textile substrate has a bonded / mesh-like (knitted), woven or non-woven structure.

  Textile substrates can be treated with dyes, colorants, pigments, UV absorbers, plasticizers, antifouling agents, lubricants, antioxidants, flame retardants, rheology agents, etc. before or after coating, but preferably Such additions are made before coating.

  When the specified nonwoven fabric is immersed in an elastomer polymer and a coagulant and then subjected to a normal coloring process, a suede-like synthetic leather having good color development properties is obtained.

  Therefore, the present invention further relates to a coated fabric, preferably a synthetic leather, obtainable by the method of the present invention.

Dispersion A having the following composition:
Ca (NO ₃ ) ₂ : 80 pbw
Methyl cellulose: 0.4 pbw
Water: 920pbw

Dispersion B1:
Impranil 1380: 1000 pbw
Water: 5000pbw

  A method for preparing a coated fabric using salt coagulation is shown in FIG.

Dispersion B2 having the following composition:
Impranil DLU: 100 pbw
Coagulant WS: 20pbw
Emulvin WA: 20pbw
Water: 5000pbw

  A method for preparing a coated fabric using thermal coagulation is shown in FIG.

  The substrate treated in a way that it did not come into contact with the dispersion A had a very hard and stiff feel. On the other hand, the base material processed according to the present invention had favorable flexibility and bending feeling. Similarly, in subsequent coatings of the resulting substrate, a possible difference between the substrate treated with Dispersion A and the untreated substrate becomes apparent, and when the coagulant is untreated, The folds (folds) collapsed significantly and / or swollen. The substrate treated in accordance with the present invention exhibited a rounded optically complete turn.

Claims (11)

at least,
(A) contacting the textile substrate with an aqueous dispersion A comprising at least one inorganic salt and at least one modified cellulose;
(B) A method for producing a coated fabric comprising a step of bringing a fabric substrate into contact with an aqueous dispersion B containing polyurethane, and (c) a step of depositing polyurethane in or on the fabric substrate.   The method 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.   The alkali metal salt is a salt selected from the group consisting of alkali metal halides, alkali metal nitrates, alkali metal phosphates, alkali metal sulfates, alkali metal carbonates and alkali metal bicarbonates. The method described.   Alkaline earth metal salts from alkaline earth metal halides, alkaline earth metal nitrates, alkaline earth metal phosphates, alkaline earth metal sulfates, alkaline earth metal carbonates and alkaline earth metal bicarbonates The method of claim 2, wherein the salt is selected from the group consisting of:   The process according to claim 1, wherein the inorganic salt is present in the dispersion A in an amount of 0.01 to 25% by weight relative to the total amount of the dispersion A.   The modified cellulose is a compound selected from the group consisting of methylcellulose, ethylcellulose, propylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, carboxyethylcellulose and carboxypropylcellulose. the method of.   The process according to claim 1, wherein the modified cellulose is present in dispersion A in an amount of 10 ppm to 5% by weight relative to the total weight of dispersion A.   2. Process according to claim 1, characterized in that the woven substrate used is a woven, knitted or non-woven fabric based on natural and / or synthetic fibers.   The process according to claim 1, characterized in that in step (c) the polyurethane is precipitated in a bath containing water or by using a temperature in the range of 80-120 ° C.   A coated fabric obtained by the method according to claim 1.   The coated fabric according to claim 10, wherein the coated fabric is a synthetic leather.

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