JP2019526714A - Method for coating fabric - Google Patents

Abstract

The present invention relates to a method for coating a fabric and the resulting coated fabric. The method comprises the following steps: a) contacting the fabric with a component A) comprising a water-insoluble salt, a water-soluble thickener, and water; and b) contacting the fabric contacted with component A) with an aqueous polymer dispersion. And contacting with component B) comprising an acid capable of reacting with the water-insoluble salt in component A) to obtain a coated fabric. The method provided in the present invention does not use an organic solvent, but allows the fabric obtained by coating to have a good hand, such as softness.

Description

  The present invention relates to a method for coating a fabric and the resulting coated fabric.

  The coated fabric can be used for the production of synthetic leather. Synthetic leather is often used as an upper material for shoes, for clothing, or in furniture decoration. The method for coating the fabric typically uses a polyurethane solution dissolved in an organic solvent such as DMF. One of the common methods for coating a fabric is to first impregnate the fabric with a polyurethane-containing solution, and then pass the fabric through the DMF / water bath multiple times, each DMF / water bath It is a solidification method including the process in which the ratio of the water in it increases in steps. The coated fabric obtained using coagulation has good breathing activity and soft hand and is suitable for use as high quality synthetic leather. However, the toxicity of organic solvents during the coating process is detrimental to worker health. In order to reduce worker health hazards caused by organic solvents, factories need to use additional protective measures, which increases production costs. Furthermore, the solidification process produces a large amount of DMF and water azeotrope, which requires subsequent processing.

  Methods for coating fabrics without the use of organic solvents have been developed in the industry. US 2004/121113 A1 describes a method for producing synthetic leather: impregnating a nonwoven fabric or woven fabric with a dispersion comprising a nonionic polyurethane and an external stabilizing surfactant; coagulating the dispersion Discloses exposing the impregnated fabric to water containing a coagulant for a coagulation time sufficient to allow. A coagulant is a neutral salt of a polyvalent cation that can dissolve in water and coagulate an aqueous polyurethane dispersion; it also reacts with additives to the water surface of organic acids on the fabric surface Salt can be produced, thereby imparting good water resistance to the fabric.

  Chinese Patent No. 10399867A first impregnates a fabric with an aqueous dispersion containing a water-soluble organic onium salt and modified cellulose; and then impregnates the fabric with an aqueous dispersion containing polyurethane; finally, the fabric Discloses a method for coating a fabric comprising depositing an aqueous dispersion of polyurethane on the surface of the fabric.

  In Chinese Patent No. 10300386A and Chinese Patent No. 103987891A, a fabric is first prepared with an aqueous dispersion containing a water-soluble inorganic salt such as calcium nitrate, magnesium nitrate, calcium chloride, or magnesium chloride and a modified cellulose. Impregnating; and then impregnating the fabric with an aqueous dispersion comprising a polymer of polyurethane, polyacrylate, or polybutadiene; and finally, coating the fabric, including attaching an aqueous dispersion of polyurethane to the fabric. The method is disclosed.

  In the fabric coating method described above, when a water-soluble organic onium salt or inorganic salt comes into contact with an aqueous dispersion of polyurethane, polyacrylate, or polybutadiene, it is released from the water-soluble organic onium salt or inorganic salt. Aqueous dispersions of metal cations and polyurethane, polyacrylate, or polybutadiene are rapidly deposited on the surface of the fabric and in the gaps of the fabric fibers, thereby reducing the coating work time. Furthermore, deposits in the gaps of the fabric fibers cannot be removed by a subsequent washing step, thus making the coated fabric have a hard hand, which is particularly harmful for fabric applications in the synthetic leather industry. is there.

  To address the above problems, a method for coating a fabric that does not use an organic solvent such as DMF but allows for a coated fabric having good properties such as a soft hand is desirable in the industry.

US Patent Application Publication No. 2004 / 121113A1 Chinese Patent No. 10399867A Chinese Patent No. 10300386A Specification Chinese Patent No. 103987891A Specification

  It is an object of the present invention to provide a method and a coated fabric for coating the fabric.

In one embodiment according to the present invention, the method for coating a fabric comprises:
a) contacting the fabric with a component A) comprising a water-insoluble salt, a water-soluble thickener and water; and b) water-insoluble in the aqueous polymer dispersion and component A) the fabric contacted with component A). Contacting with a component B) comprising an acid capable of reacting with a salt to obtain a coated fabric.

  Preferably, the method is performed in the absence of an organic solvent.

  In an embodiment according to the present invention, the coated fabric provided by the present invention is obtained by performing a method for coating the fabric provided by the present invention.

  Preferably, the coated fabric is free of water insoluble salts.

  The coated fabric can be synthetic leather.

  The fabric may be a woven fabric, a knitted fabric, or a non-woven fabric based on natural and / or synthetic fibers, preferably a non-woven fabric such as a short fiber non-woven fabric or a very fine fiber non-woven fabric.

  The fabric may be composed of polyester fiber, nylon fiber, cotton fiber, polyester / cotton blended fiber, wool fiber, ramie fiber, spandex fiber, glass fiber, thermoplastic polyurethane fiber, or thermoplastic olefin fiber.

  The fabric may have a web structure, a woven structure, or a non-woven structure.

  The method for coating fabrics provided by the present invention makes it possible to eliminate the use of organic solvents, which is advantageous for the health of workers and requires an additional step for the separation of organic solvents. The longer the workable period for coating the fabric; and the resulting coated, such as softness, characteristic of coated fabrics obtained by coating processes using organic solvents. Brings a good feel to the fabric.

  The present invention includes: a) contacting the fabric with a component A) comprising a water-insoluble salt, a water-soluble thickener, and water; and b) an aqueous polymer dispersion and component A) contacting the fabric contacted with component A). There is provided a method for coating a fabric comprising the step of contacting with a component B) comprising an acid capable of reacting with a water-insoluble salt therein to obtain a coated fabric. The present invention also provides a coated fabric obtained by carrying out the method for coating this fabric.

  The term “contact” is generally to be understood as dipping or coating. The immersion may be partial immersion or complete immersion, preferably complete immersion. The coating can be performed by means such as hand coater, printing, or spraying.

  The term “aqueous polyurethane dispersion” may further include an aqueous polyurethane-polyurea dispersion.

  The term “water-insoluble salt” is generally to be understood as a salt that is completely insoluble in water or has a very low solubility in water.

Step a)
The fabric may be a woven fabric, a knitted fabric, or a non-woven fabric based on natural and / or synthetic fibers, preferably a non-woven fabric such as a short fiber non-woven fabric or a very fine fiber non-woven fabric.

  The fabric may be composed of polyester fiber, nylon fiber, cotton fiber, polyester / cotton blended fiber, wool fiber, ramie fiber, spandex fiber, glass fiber, thermoplastic polyurethane fiber, or thermoplastic olefin fiber.

  The fabric may have a web structure, a woven structure, or a non-woven structure.

Component A )
The amount of water insoluble salt is 0.5-50% by weight, preferably 0.5-25% by weight, more preferably 0.5-15% by weight, based on the amount of component A as 100% by weight, most preferably Preferably, it is 0.5 to 10% by weight.

  The water-insoluble salt can have a particle size of 2000-6000 mesh, preferably 2000-4000 mesh.

  The water-insoluble salt is preferably a polyvalent water-insoluble inorganic salt.

  The polyvalent water-insoluble inorganic salt is preferably a divalent water-insoluble inorganic salt.

  The divalent water-insoluble inorganic salt is preferably selected from one or more of calcium carbonate, magnesium carbonate, barium carbonate, calcium phosphate, magnesium phosphate, barium phosphate, calcium oxalate, magnesium oxalate, and barium oxalate Most preferred is calcium carbonate.

  The amount of thickener, based on the amount of component A as 100% by weight, is 0.5-20% by weight, preferably 0.5-10% by weight, more preferably 0.5-5% by weight, most Preferably, it is 0.5 to 1.5% by weight.

  The water-soluble thickener is selected from one or more of alkylated cellulose, hydroxyalkylated cellulose, and carboxyalkylated cellulose.

  The alkylated cellulose is selected from one or more of methylcellulose, ethylcellulose, and propylcellulose.

  The hydroxyalkylated cellulose is selected from one or more of hydroxymethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose.

  The carboxyalkylated cellulose is selected from one or more of carboxymethylcellulose, carboxyethylcellulose, and carboxypropylcellulose, most preferably carboxymethylcellulose.

  The fabric is preferably in contact with component A) for 2-4 minutes, more preferably 1-2 minutes, most preferably 0.2-1 minute.

  The water content in component A) is the balance that makes the amount of component A) 100% by weight.

Step b)
In step b), the fabric in contact with component A) is brought into contact with component B). The acid in component B) reacts with the water-insoluble salt in component A) remaining on the fabric, and the aqueous polymer dispersion in component B) precipitates on the surface of the fabric.

  The reaction temperature is preferably 80 to 180 ° C, and most preferably 80 to 120 ° C.

  The reaction time is preferably 0.2 to 30 minutes, and most preferably 1 to 30 minutes.

Component B)
In step b), the fabric in contact with component A) is preferably contacted with component B) for 0.2 to 4 minutes, more preferably 0.2 to 2 minutes, most preferably 0.2 to 1 minute.

  The solids content in the aqueous polymer dispersion is from 10 to 50% by weight, preferably from 25 to 50% by weight, based on the amount of component B) as 100% by weight.

  The aqueous polymer dispersion is a water-soluble polymer, preferably an aqueous polyurethane dispersion, an aqueous polyacrylate dispersion, an aqueous polybutadiene dispersion, a rubber latex (an aqueous dispersion of rubber fine particles), or a styrene-butadiene latex (polymerization of butadiene and styrene). Selected from one or more of: a water dispersion formed by polymerization of butadiene and acrylonitrile, a water dispersion formed by polymerization of butadiene and acrylonitrile, and a neoprene latex formed by homopolymerization of polybutadiene. Most preferred is an aqueous polyurethane dispersion.

Aqueous polyurethane dispersion The aqueous polyurethane dispersion has a residual organic solvent content of less than 1.0% by weight, based on the amount of aqueous polyurethane dispersion as 100% by weight.

  The aqueous polyurethane dispersion preferably has a pH value in the range of less than 9.0, more preferably less than 8.5, more preferably less than 8.0, and most preferably 6.0 to 8.0.

  The aqueous polyurethane dispersion is preferably 10 to 70 wt%, more preferably 50 to 65 wt%, most preferably 55 to 65 wt% solids based on the amount of aqueous polyurethane dispersion as 100 wt%. Have minutes.

  The aqueous polyurethane dispersion is preferably an aqueous anionic and / or nonionic polyurethane dispersion, most preferably an aqueous anionic polyurethane dispersion.

  The aqueous anionic polyurethane dispersion contains a small amount of hydrophilic anionic groups. The hydrophilic anionic group is preferably in an amount of 0.1-15 mg equivalent / 100 g solid polyurethane.

The aqueous anionic and / or nonionic polyurethane dispersion is preferably obtained by the following steps:
Step I):
Ia) organic polyisocyanates,
Ib) Number average molecular weight in the range of 400 to 8000 g / mol, preferably 400 to 6000 g / mol, particularly preferably 600 to 3000 g / mol, and 1.5 to 6, preferably 1.8 to 3, particularly preferably 1. A polymer polyol having a hydroxyl functionality in the range of 9 to 2.1;
Ic) optionally a hydroxyl-functional compound having a molecular weight in the range of 32-400 g / mol, and Id) optionally an isocyanate-functional prepolymer from an isocyanate-reactive, anionic, or potentially anionic hydrophilizing agent. Polymer preparation,
Step II) All or some of the free isocyanate (NCO) groups of the isocyanate functional prepolymer and the following materials for chain extension:
IIa) optionally with an amino-functional compound having a molecular weight in the range of 32-400 g / mol, and / or IIb) an isocyanate-reactive, preferably amino-functional, anionic or potentially anionic hydrophilizing agent reaction,
Here, the resulting isocyanate-functional prepolymer is dispersed in water before, during or after step II), wherein any potentially anionic groups present are partially or neutralized with the neutralizing agent. By complete reaction, it is preferably converted to the ionic form after step II).

  Solvents still present in the aqueous polyurethane dispersion after dispersion can be removed by distillation. The solvent can also be removed during dispersion.

In a preferred embodiment for the preparation of the aqueous polyurethane dispersion, the components Ia) to Id) and IIa) to IIb), in which the individual amounts always result in a total of 100% by weight, are in the following amounts:
5 to 40% by weight of component Ia),
55-90% by weight Ib),
A total of 0.5 to 20% by weight of components Ic) and IIa),
A total of 0.1 to 25% by weight of components Id) and IIb),
Based on the total amount of components Ia) to Id) and IIa) to IIb) as 100% by weight, anionic or potentially from 0.1 to 5% by weight of Id) and / or IIb) An anionic hydrophilizing agent is used.

In another preferred embodiment for the preparation of the aqueous polyurethane dispersion, the components Ia) to Id) and IIa) to IIb), the individual amounts always totaling 100% by weight, are in the following amounts:
5 to 35% by weight of component Ia),
60-90% by weight Ib),
A total of 0.5 to 15% by weight of components Ic) and IIa),
A total of 0.1 to 15% by weight of components Id) and IIb),
Based on the total amount of components Ia) to Id) and IIa) to IIb) as 100% by weight, anionic or potentially from 0.2 to 4% by weight of Id) and / or IIb) An anionic hydrophilizing agent is used.

In yet another preferred embodiment for the preparation of the aqueous polyurethane dispersion, the components Ia) to Id) and IIa) to IIb), the individual amounts always totaling 100% by weight, are in the following amounts:
10-30% by weight of component Ia),
65-85 wt% Ib),
A total of 0.5 to 14% by weight of components Ic) and IIa),
A total of 0.1 to 13.5% by weight of components Id) and IIb),
Anionic or latent from 0.5 to 3.0% by weight of Id) and / or IIb), based on the total amount of components Ia) to Id) and IIa) to IIb) as 100% by weight An anionic hydrophilizing agent is used.

  In step I), the ratio of isocyanate groups in the organic polyisocyanate in component Ia) to isocyanate reactive groups in components Ib) to Id), such as amino groups, hydroxyl groups, or thiol groups, is 1.05 to 3 0.5, preferably 1.2 to 3.0, most preferably 1.3 to 2.5.

In step I), the organic polyisocyanate in component Ia) can be an aromatic, araliphatic, aliphatic or cycloaliphatic organic polyisocyanate having an isocyanate functionality of 2. Examples 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 having any desired isomer content, 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′-diisocyanatodiphenylmethane, 1,3- and / or 1, 4-Bis (2-isocyanatoprop-2-yl) -benzene (TMXDI ), 1,3-bis (isocyanatomethyl) benzene (XDI), and alkyl 2,6-diisocyanato-hexanoates (lysine diisocyanates) containing C ₁ -C ₈ -alkyl groups, preferably 1,6-hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI) or isomeric bis (4,4′-isocyanatocyclohexyl) methane, or mixtures thereof.

  In step I), the organic polyisocyanate in component Ia) can also be a modified diisocyanate having a uretdione, isocyanurate, urethane, allophanate, biuret, imino-oxadiazinedione, and / or oxadiazinetrione structure.

  In step I), the organic polyisocyanate in component Ia) is further a non-modified polyisocyanate containing more than 2 NCO groups per molecule, such as 4-isocyanatomethyloctane, 1,8-diisocyanate (nonane triisocyanate). ), Or triphenylmethane 4,4 ′, 4 ″ -triisocyanate.

  In step I), the polymer polyol in component Ib) is a polyester polyol, polyacrylate polyol, polyurethane polyol, polycarbonate polyol, polyether polyol, polyester polyacrylate polyol, polyurethane polyacrylate polyol, polyurethane polyester polyol, polyurethane polyether polyol, It can be one or more of polyurethane polycarbonate polyols and polyester polycarbonate polyols, which are commonly used in the preparation of aqueous polyurethane dispersions.

  Polyester polyols can be polycondensates of di- and optionally tri- and tetraols with di- and optionally tri- and tetracarboxylic acids or hydroxycarboxylic acids or lactones. As long as the average functionality of di- and optionally tri- and tetraol is greater than 2, monocarboxylic acids can also be used in the condensation to synthesize polyester polyols, the monocarboxylic acid being benzoic acid and / or It can be heptanoic acid.

  Diols include polyalkylene glycols such as ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, and 1,4-butanediol. 1,6-hexanediol and its isomers, neopentyl glycol, and neopentyl glycol hydroxypivalate. One or more of 1,6-hexanediol and its isomer, neopentyl glycol, and neopentyl glycol hydroxypivalate are preferred.

  The tri- and tetraol can be one or more of trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene, and trishydroxyethyl isocyanurate.

  Dicarboxylic acids are phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, tetrachlorophthalic acid, maleic acid, fumaric acid, itacone It may be one or more of acids, malonic acid, suberic acid, 2-methyl succinic acid, 3,3-diethyl glutaric acid, and 2,2-dimethyl succinic acid. Corresponding anhydrides can also be used as the acid source of the dicarboxylic acid.

  The lactone is one or more of caprolactone, caprolactone congeners, butyrolactone, and butyrolactone congeners, preferably caprolactone.

  The polycarbonate polyol preferably has a number average molecular weight ranging from 400 to 8000 g / mol, most preferably from 600 to 3000 g / mol.

  The polycarbonate polyol preferably has a linear structure and most preferably has a polycarbonate diol.

  The polycarbonate diol preferably contains 40 to 100% by weight of hexanediol. The hexanediol is preferably 1,6-hexanediol and / or a hexanediol derivative. Hexanediol derivatives are hexanediol-based and contain ester or ether groups in addition to terminal hydroxyl groups, obtained by reaction of hexanediol with excess caprolactone or by etherification of hexanediol itself, and dihexane This produces diol or trihexanediol.

  The polyether polyol can be a polytetramethylene glycol polyether obtained by cationic ring-opening polymerization of tetrahydrofuran.

  The polyether polyol can also be an addition product of styrene oxide, ethylene oxide, propylene oxide, butylene oxide, and / or epichlorohydrin to a difunctional or polyfunctional starting molecule.

  The starting molecule can be one or more of water, butyl diglycol, glycerol, diethylene glycol, trimethylolpropane, propylene glycol, sorbitol, ethylenediamine, ethylene glycol, triethanolamine, and 1,4-butanediol.

  Ib) The polymer polyol most preferably comprises a polycarbonate polyol and a polybutylene glycol polyol. The polycarbonate polyol and polybutylene glycol polyol are present in an amount of at least 50% by weight, preferably 60% by weight, particularly preferably 70% by weight, based on the amount of polymer polyol as 100% by weight.

  The polycarbonate polyol is present in an amount of 20-80 wt%, preferably 25-70 wt%, most preferably 30-65 wt%, based on the total weight of the polycarbonate polyol and polybutylene glycol polyol as 100 wt% To do. The polybutylene glycol polyol is in an amount of 20-80 wt%, preferably 30-75 wt%, most preferably 35-70 wt%, based on the total weight of the polycarbonate polyol and polybutylene glycol polyol as 100 wt%. Exists.

  Ic) hydroxyl functional compounds are 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, and polyols having up to 20 carbon atoms, such as one or more of pentaerythritol.

  Ic) The hydroxyl functional compound is also one or more of α-hydroxybutyl-ε-hydroxycaproate, ω-hydroxyhexyl-γ-hydroxybutyrate, β-hydroxyethyl adipate, or β-hydroxyethyl terephthalate. Or an ester diol.

  Ic) The hydroxyl-functional compound can further be a monofunctional or isocyanate-reactive hydroxyl-functional compound. Monofunctional or isocyanate-reactive hydroxyl functional group-containing compounds include 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, 1 , 6-Hexanediol 1,4-butyle One or more of glycol, neopentyl glycol, and trimethylol propane, preferably one or more of 1,6-hexanediol, 1,4-butylene glycol, neopentyl glycol, and trimethylol propane. .

Id) Isocyanate-reactive, anionic or potentially anionic hydrophilizing agents include at least one or more isocyanate-reactive groups such as hydroxyl groups, and —COO ⁻ M ⁺ , —SO ^{3 −} M ⁺ , —PO A compound containing at least one or more functional groups such as (O ⁻ M ⁺ ) ₂ , wherein M ⁺ can be a metal cation, H ⁺ , NH ⁴⁺ , NHR ³⁺ , and R is C ₁ -C ₁₂ - _alkyl, C 5 -C ₆ - cycloalkyl, and / or _C 2 -C ₄ - can be an hydroxyalkyl group includes compounds. The functional group may be negatively or neutrally charged because it enters a pH-dependent dissociation equilibrium upon interaction with an aqueous medium.

  Id) Isocyanate-reactive, anionic or potentially anionic hydrophilizing agents are preferably mono- and dihydroxycarboxylic acids, mono- and dihydroxysulfonic acids, and mono- and dihydroxyphosphonic acids and their salts . More preferably, carboxylate or carboxylic acid groups and / or sulfonate groups are contained.

  IIa) The amino functional compound is selected from one or more of 1,2-ethylenediamine, 1,4-diaminobutane, and isophoronediamine.

IIb) Anionic or potentially anionic hydrophilizing agents include at least one or more isocyanate-reactive groups such as amino groups, and —COO ⁻ M ⁺ , —SO ^{3 −} M ⁺ , —PO (O ⁻ M ⁺ ) A compound containing at least one or more functional groups such as ₂ , wherein M ⁺ can be a metal cation, H ⁺ , NH ⁴⁺ , NHR ³⁺ , wherein R is C ₁ -C ₁₂ -alkyl, C ₅ -C ₆ - cycloalkyl, and / or _C 2 -C ₄ - can be an hydroxyalkyl group includes compounds. The functional group may be negatively or neutrally charged because it enters a pH-dependent dissociation equilibrium upon interaction with an aqueous medium.

  The aqueous polyurethane dispersion may be prepared by using a prepolymer mixing method, an acetone method, or a melt dispersion method, and the acetone method is preferably used.

  According to the acetone method, usually all or part of Ia) to Id) is initially introduced for the preparation of the isocyanate-functional prepolymer and is miscible with water but inert to isocyanate groups. It may be diluted with a solvent and heated to a temperature in the range of 50-120 ° C.

  The solvent can be a conventional aliphatic keto functional solvent such as acetone, 2-butanone. The solvent can be added only at the start of the preparation, and can be further partially added during the preparation if desired.

  The solvent can also be xylene, toluene, cyclohexane, butyl acetate, methoxypropyl acetate, N-methylpyrrolidone, N-ethylpyrrolidone, or a solvent containing ether or ester units.

  Components Ia) to Id) that have not yet been added at the start of the reaction are then metered in.

  In the preparation of isocyanate functional prepolymers from components Ia) -Id), the molar ratio of isocyanate groups to isocyanate-reactive groups is 1.05-3.5, preferably 1.2-3.0, most preferably It is in the range of 1.3 to 2.5.

  The conversion of components Ia) to Id) into an isocyanate-functional prepolymer is carried out partly or completely, preferably completely.

  The isocyanate functional prepolymer obtained by step I) can be in the solid state or in the liquid state.

  If the resulting isocyanate functional prepolymer is undissolved or only partially dissolved, the prepolymer is further dissolved using an aliphatic ketone such as acetone or 2-butanone.

In step II), NH ₂ ^- and / or NH ^- functional components, partially or complete reaction with the remaining isocyanate groups of the isocyanate functional prepolymer. Chain extension or chain termination is preferably performed before being dispersed in water.

  For chain termination, IIa) amino-functional compounds 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, diprimary diamines or primarys made from diprimary amines and monocarboxylic acids Secondary / tertiary amines such as N, N-dimethylaminopropylamine are usually used.

  Components IIa) and IIb) can optionally be used individually or in mixtures, diluted with water or solvent, if any order of addition is possible.

The aqueous polyacrylate dispersion, the aqueous polybutadiene dispersion, the aqueous polyacrylate dispersion, and the aqueous polybutadiene dispersion can be prepared according to known free radical polymerization methods such as solution polymerization, emulsion polymerization, and suspension polymerization. The preparation can be continuous or discontinuous, preferably discontinuous.

  The aqueous polyacrylate dispersion and the aqueous polybutadiene dispersion can be selected from commercially available products.

Acid acid capable of reacting with the water-insoluble salt, based on the amount of component B) as 100% by weight, 0.1 to 50 wt%, preferably be in an amount of from 0.5 to 5 wt%.

  The acid may have a concentration of 1-20%, preferably 5-10%.

  The acid is selected from one or more of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, formic acid, and acetic acid.

Step c)
The method for coating a fabric provided by the present invention comprises the steps of c) contacting the fabric contacted with component B) with water to form a water soluble component on the surface of the coated fabric or in the gaps of the fabric fibers. May be further included.

  The water temperature is 0-90 ° C. The fabric in contact with component B) is preferably in contact with water for 2-4 minutes, more preferably 1-2 minutes, most preferably 0.2-1 minute.

  After the fabric comes into contact with water in step c), it generally requires a squeezer device to squeeze the fabric. Step c) and the squeezing step may be repeated, for example, more than three times, followed by post-treatment such as drying. The squeezing process is carried out so that the liquid remains in the fabric in an amount of 30-400% by weight, preferably 30-180% by weight, more preferably 30-140% by weight, most preferably 30-120% by weight. The amount of liquid remaining in the fabric is the ratio of the weight of residual liquid in the fabric to the total weight of the fabric (including residual liquid).

Part or all of the liquid in the fabric from the squeezing and drying step a), step b), or step c) can be removed before subjecting the fabric to the next step.

  The process for removing some or all of the liquid in the fabric can be squeezing and / or drying.

  The squeezing step squeezes the fabric with a squeezer device comprising two rollers and is 30-400% by weight in the fabric, preferably 30-180% by weight, more preferably 30-140% by weight, most preferably 30-120% by weight. It may refer to making it possible to leave a% amount of liquid. The amount of liquid remaining in the fabric is the ratio of the weight of residual liquid in the fabric to the total weight of the fabric (including residual liquid).

  Drying may refer to physical drying or chemical drying. The period for drying is preferably 1 to 10 minutes, most preferably 1 to 5 minutes. The temperature for drying is 70-150 ° C. Part or all of the fabric can be dried during the drying process.

  Physical drying can refer to air drying, infrared cylinder, or hot cylinder drying.

  Chemical drying can refer to drying by contacting the fabric with a crosslinker.

  The crosslinker can be a crosslinker based on isocyanate, melamine, aziridine, or carbodiimide.

  The fabric can be treated with additives before, during or after coating, preferably before coating. The additive is selected from dyes, colorants, pigments, UV absorbers, plasticizers, soil redeposition agents, lubricants, antioxidants, flame retardants, or rheology agents.

  On the other hand, the method for coating a fabric provided by the present invention is beneficial to the health of workers and has an additional step for separating the organic solvent by using an aqueous component instead of the organic solvent. do not need. On the other hand, the water-insoluble salt comes into contact with an acid that can react with the water-insoluble salt and slowly release metal ions that slowly precipitate with the aqueous polymer dispersion on the surface of the fabric. The present invention not only prolongs the workable period for coating the fabric, but also provides a water-soluble thickener that takes enough time to enter the fabric fiber gap, thereby providing a solution within the fabric fiber gap. Reduce precipitation of aqueous polymer dispersions. In the next washing step, the water-soluble thickener in the fabric fiber gaps is washed away to release the fabric fiber gaps and give the coated fabric a good feel. In another aspect, the water-insoluble salt reacts with an acid that can react with the water-insoluble salt to release a gas, such as carbon dioxide, as the aqueous polymer dispersion precipitates to impart elasticity to the precipitate. It can enter the sediment and further optimize the good hand of the coated fabric.

[Example]
All percentages used in the present invention are weight percentages unless otherwise indicated.

Preparation method of component A) Ca (CO ₃ ) ₂ 0.7% by weight
CMC FH6 0.8 wt%
98.5% by weight of water
After charging water into the container according to the above ratio, stirring was started. CMCFH6 was added to the container. After the liquid in the container became transparent from opaque, Ca (CO ₃ ) ₂ was added thereto, and the mixture was stirred for 40 to 60 minutes to obtain a component A) solution.

Preparation method of component B) Impranil DLE 50% by weight
Acetic acid 0.5% by weight
49.5% by weight of water
After charging water into the container according to the above ratio, stirring was started. Impranil DLE and acetic acid were added to the vessel and the mixture was stirred for 5-10 minutes to obtain a component B) solution.

[Example 1]
The ultrafine fiber nonwoven was dipped in component A) for 12 seconds, then removed and squeezed with a squeezer device at a pressure of 4 bar, allowing the liquid to remain in the ultrafine fiber nonwoven in an amount of 120%. Subsequently, it was dried for 5 minutes in a temperature range of 110 to 140 ° C. Thereafter, the ultrafine fiber nonwoven fabric was immersed in component B) for 15 seconds, and then taken out and placed at 80 ° C. for 10 minutes to precipitate Impranil DLE on the surface of the ultrafine fiber nonwoven fabric. Subsequently, the ultrafine fiber nonwoven was squeezed with a squeezer device at a pressure of 4 bar, allowing the liquid to remain in the ultrafine fiber nonwoven in an amount of 150%. After drying at 90 ° C. for 3 minutes, the ultrafine fiber nonwoven is immersed in 80 ° C. water and washed for 1 minute, then squeezed with a squeezer device at a pressure of 4 bar, and the amount of liquid is 30% in the ultrafine fiber nonwoven. Made it possible to remain in. The washing and squeezing process was repeated 4 times. Finally, the ultrafine fiber nonwoven fabric was completely squeezed with a squeezer device and dried at 110 to 150 ° C. for 5 minutes to obtain a coated ultrafine fiber nonwoven fabric.

[Example 2]
The single-sided pile knitted fabric was soaked in component A) for 60 seconds, then removed and squeezed with a squeezer device at a pressure of 4 bar, allowing the liquid to remain in the single-sided pile knitted fabric in an amount of 180%. Subsequently, after impregnating the single-sided pile knitted fabric in Component B) for 120 seconds, the single-sided pile knitted fabric was taken out and allowed to stand at 100 ° C. for 20 minutes to precipitate Impranil DLE on the surface of the single-sided pile knitted fabric. After drying at 90 ° C. for 3 minutes, the single-sided pile knitted fabric is immersed in 50 ° C. water for 2 minutes, then squeezed with a squeezer device at a pressure of 4 bar, and the liquid is 80% in the single-sided pile knitted fabric Made it possible to remain in quantity. The washing and squeezing process was repeated 4 times. Finally, the single-sided pile knitted fabric was completely drawn with a squeezer device and dried at 110 to 150 ° C. for 5 minutes to obtain a coated single-sided pile knitted fabric.

[Comparative Example 1]
The ultrafine fiber nonwoven is immersed in a solution containing 1% by weight CaCl ₂ , 0.8% by weight CMC FH6, 0.2% by weight BYK 349, and 98% by weight water, then removed and taken out at 4 bar. Squeezing with a squeezer device at a pressure of 120% allowed the liquid to remain in the microfiber nonwoven fabric in an amount of 120%. Subsequently, it was dried for 5 minutes in a temperature range of 110 to 140 ° C. Then, after immersing the ultrafine fiber nonwoven fabric in a solution containing 50% by weight of Impranil DLE and 50% by weight of water for 15 seconds, it is taken out and allowed to stand at 80 ° C. for 10 minutes to precipitate Impranil DLE on the surface of the ultrafine fiber nonwoven fabric. It was. Subsequently, the ultrafine fiber nonwoven was squeezed with a squeezer device at a pressure of 4 bar, allowing the liquid to remain in the ultrafine fiber nonwoven in an amount of 150%. After drying at 90 ° C. for 3 minutes, the ultrafine fiber nonwoven is immersed in 80 ° C. water and washed for 1 minute, then squeezed with a squeezer device at a pressure of 4 bar, and the amount of liquid is 30% in the ultrafine fiber nonwoven. Made it possible to remain in. The washing and squeezing process was repeated 4 times. Finally, the ultrafine fiber nonwoven fabric was completely squeezed with a squeezer device and dried at 110 to 150 ° C. for 5 minutes to obtain a coated ultrafine fiber nonwoven fabric.

  Comparison of the examples and comparative examples shows that the coated fabric obtained in the comparative example has a hard hand and is prone to wrinkling and slumping after the fabric is folded and released, as described in the examples. The fabric obtained by coating according to the method prepared has a soft hand and does not wrinkle and slump after the fabric is folded and released.

  It will be readily appreciated by those skilled in the art that the present invention is not limited to the specific details described above, but can be implemented in other specific forms without departing from the spirit or key features of the present invention. Accordingly, from any point of view, the examples should be regarded as illustrative rather than limiting, so the scope of the present invention should be presented according to the claims rather than the foregoing description. is there. Accordingly, any changes should be considered as relevant to the invention as long as they come within the meaning and range of equivalents of the claims.

Claims (18)

A method for coating a fabric comprising:
a) contacting the fabric with a component A) comprising a water-insoluble salt, a water-soluble thickener, and water; and b) the fabric in contact with component A) in an aqueous polymer dispersion and component A). Contacting with component B) comprising an acid capable of reacting with said water-insoluble salt to obtain a coated fabric.   The method according to claim 1, wherein the water-insoluble salt is a polyvalent water-insoluble inorganic salt.   The method according to claim 2, wherein the polyvalent water-insoluble inorganic salt is a divalent water-insoluble inorganic salt.   The divalent water-insoluble inorganic salt is selected from one or more of calcium carbonate, magnesium carbonate, barium carbonate, calcium phosphate, magnesium phosphate, barium phosphate, calcium oxalate, magnesium oxalate, and barium oxalate. The method according to claim 3, wherein:   5. Process according to any of claims 1 to 4, characterized in that the water-insoluble salt is present in an amount of 0.5 to 50% by weight, based on the amount of component A) as 100% by weight. .   The method of claim 1, wherein the water-soluble thickener is selected from one or more of alkylated cellulose, hydroxyalkylated cellulose, and carboxyalkylated cellulose.   The method according to claim 6, wherein the carboxyalkylated cellulose is carboxymethylcellulose.   8. The water-soluble thickener is present in an amount of 0.5 to 20% by weight, based on the amount of component A) as 100% by weight. the method of.   The aqueous polymer dispersion is selected from one or more of an aqueous polyurethane dispersion, an aqueous polyacrylate dispersion, an aqueous polybutadiene dispersion, a rubber latex, a styrene-butadiene latex, a butadiene-acrylonitrile latex, and a neoprene latex. The method of claim 1, wherein:   The method according to claim 9, wherein the aqueous polyurethane dispersion is an aqueous anionic polyurethane dispersion.   11. A process according to claim 1, 9 or 10, characterized in that the solids content in the aqueous polymer dispersion is 10 to 50% by weight, based on the amount of component B) as 100% by weight. .   The method of claim 1, wherein the acid is selected from one or more of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, formic acid, and acetic acid.   13. Process according to claim 1 or 12, characterized in that the acid is present in an amount of 0.1 to 50% by weight, based on the amount of component B) as 100% by weight.   The method of claim 1 further comprising the step c) of contacting the fabric in contact with component B) with water.   The method according to claim 1, wherein the method is performed in the absence of an organic solvent.   Coated fabric obtainable by carrying out the method according to any one of claims 1-15.   The coated fabric of claim 16, wherein the coated fabric is free of water insoluble salts.   A coated fabric according to claim 16 or 17, characterized in that the coated fabric is synthetic leather.