JP2000290879A - Method for producing fiber sheet-like composite and artificial leather - Google Patents

Abstract

(57) [Object] The object of the present invention is to provide a water-based resin composition having sharp thermocoagulability in thermocoagulation by steam and uniformly filled between fibers by thermocoagulation, after drying. The present invention relates to a method for producing a fibrous sheet-like composite which forms a porous layer and gives a feeling similar to that of a solvent system, that is, a feeling of fulfillment and a firm feeling, and its artificial leather. SOLUTION: The present invention relates to (a) an aqueous resin composition comprising (1) an aqueous urethane resin having a heat-sensitive coagulation temperature of 40 to 90 ° C. and (2) an associative thickener; The present invention relates to a method for producing a fibrous sheet-like composite, characterized by impregnating or applying to a substrate and heat-solidifying with (c) steam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fibrous sheet-like composite in which a fibrous material substrate is impregnated or coated with an aqueous urethane resin composition comprising an aqueous urethane resin and a specific thickener, and then thermally coagulated with steam. It is about the method.
More specifically, the water-based resin composition having a sharp heat-sensitive coagulation property in steam coagulation, and evenly filled between fibers by heat coagulation, forms a microporous layer after drying, and has the same texture as a solvent-based one, That is, the present invention relates to a method for producing a fibrous sheet-like composite material that gives a sense of fulfillment and a firm feeling, particularly an artificial leather.

[0002]

2. Description of the Related Art In a conventional method for producing artificial leather, a fiber material substrate is impregnated or applied with an organic solvent solution of a urethane resin,
A method called a wet coagulation method is known in which a coagulation solution (usually water) which is a poor solvent for the urethane resin and is compatible with the organic solvent is coagulated, and then washed with water and dried. However, at this time, industrially used organic solvents such as dimethylformamide (DMF) are highly toxic,
There is a problem that a large amount of cost is required for collection. In order to solve these problems, studies have been made to shift the urethane resin impregnated or applied to the fiber material base from an organic solvent type to an aqueous urethane resin, but an artificial urethane resin having satisfactory texture and physical properties has been studied. Leather has not been obtained.

A major reason for this is that when a water-based urethane resin is impregnated into a fiber material substrate and heated and dried, water evaporates from the surface of the fiber material substrate, and the water-based urethane resin is moved by the movement of the water, causing the water-based urethane resin to flow. Migration on the surface of the substrate. Due to this migration, the urethane resin migrates to the surface of the fibrous material substrate and hardly adheres to the inside, so that only artificial leather having a hard feel and easily wrinkled can be obtained. Therefore, various studies have been made to prevent this migration.

[0004] For example, there is a method of coagulating a synthetic resin emulsion having heat-sensitive coagulability by adding a heat-sensitive gelling agent as disclosed in Japanese Patent Publication No. 55-51076 in hot water. As disclosed in JP-B-59-1823, an urethane resin having a carboxyl group is prepared by emulsification with an anionic surfactant, and then a small amount of a nonionic surfactant is added to the emulsion for storage stability. Is impregnated or coated with a polyurethane emulsion compounded with a heat-sensitive coagulant, and then heat-coagulated by heating with hot air or hot water. Also,
There is also a method disclosed in JP-A-6-316877, in which an aqueous resin composition in which inorganic salts are dissolved is applied to a forcedly emulsified emulsion, followed by heating and drying. Furthermore,
As disclosed in Japanese Patent Publication No. 6-60260, an aqueous urethane resin composition to which microballoons have been added is thermally solidified, and the microballoons are foamed to form a foam.

However, although migration can be prevented, a problem arises in that a part of the impregnating liquid flows out into the coagulation bath and solidifies, and the solidified gel adheres to the surface of the workpiece. Further, there is a problem that as the polyurethane resin concentration decreases, the heat-sensitive coagulability decreases, and the urethane resin more easily flows into hot water. In the above, since the resin composition is mainly anionic, the stability of the resin composition is very poor when an inorganic salt (particularly, a divalent or higher valent metal salt) of a heat-sensitive coagulation accelerator is added, which causes a problem in formulation. is there. When the processing method is hot-air drying, microporous is not formed when the inside of the resin film is viewed, and the texture tends to become harder as the resin adhesion amount increases.
The same problem occurs when the processing method is hot water solidification.
Does not form a microporous material as in hot air drying. Further, since a large amount of the inorganic salt is used, the inorganic salt remains in the fiber after processing, and there is a problem in using it as artificial leather as it is. In, microballoons are added to form a microporous, but due to the added microballoons, coloring due to heat burn occurs, or the texture becomes hard,
Since the diameter of the porous body is large and the pores are basically independent, sufficient performance is not yet obtained in terms of texture and physical properties.

[0006] As described above, the conventional technology does not provide an artificial leather having a satisfactory texture and physical properties. In particular, the object of the present invention is to form a microporous layer of a urethane resin after drying, and to form a solvent-based leather. There was nothing that gave a feeling of fulfillment and a firm texture. In the present invention, "microporous" refers to a state in which a large number of small holes are uniformly present in a dried film of an aqueous urethane resin composition filled in fibers. (See Figure 1)

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a blended liquid (aqueous resin composition) which is stable, has a sharp heat-sensitive coagulation property by steam coagulation, and is uniform in a fiber material substrate by heat coagulation. After the aqueous resin composition filled in is dried, a microporous layer is formed, and a texture equivalent to that of a solvent system, that is, a method for producing a fibrous sheet-like composite that gives a firm feeling and a firm texture, and is obtained by the method. In artificial leather.

[0008]

Means for Solving the Problems The present inventors have made intensive studies on a method for producing a fibrous sheet-like composite, particularly an artificial leather, which solves the above-mentioned problems, and have completed the present invention.

That is, the present invention provides (1) an aqueous resin composition comprising (1) an aqueous urethane resin having a heat-sensitive coagulation temperature of 40 to 90 ° C. and (2) an associative thickener, Impregnated or applied to the fiber material substrate,
(C) A method for producing a fibrous sheet-like composite, wherein the fibrous sheet-like composite is thermally solidified with steam. (2) The aqueous urethane resin is an aqueous urethane resin dispersed with a nonionic emulsifier having an HLB of 10 to 18 (1).
The method for producing a fibrous sheet-like composite according to the above item. (3) The nonionic emulsifier having a skeleton represented by the following structural formula (I)

[0010]

Ra-Ph- (I) R: alkyl group, aryl group or alkylaryl group having 1 to 9 carbon atoms a: integer of 1 to 3 Ph: phenyl ring residue (1) to (2) The method for producing a fibrous sheet-like composite according to the above item. (4) The associative thickener has a hydrophobic group at a terminal and a urethane bond in a molecular chain (1).
The method for producing a fiber sheet composite according to any one of (1) to (3). (5) (A) a polyoxyalkylene glycol containing at least 50% by weight or more of ethylene oxide repeating units and / or (B) a polyoxyalkylene glycol containing at least 50% by weight or more of ethylene oxide repeating units in one end. The method for producing a fiber sheet-like composite according to any one of (1) to (4), which is an aqueous urethane resin containing an alkylene glycol. (6) The temperature of the steam is 70 to 120 ° C. (1)
The method for producing a fiber sheet-like composite according to any one of (1) to (5). (7) The method for producing a fiber sheet composite according to any one of (1) to (6), wherein the treatment time by steam is from 10 seconds to 20 minutes. (8) The method for producing a fibrous sheet-like composite according to (1) to (7), further comprising drying at a temperature of 80 to 150 ° C. after steam coagulation. (9) Artificial leather obtained by the production method according to any one of (1) to (8). Is provided.

The object of the present invention is to form a microporous layer after drying the aqueous resin composition which has a sharp heat-sensitive coagulation property by steam coagulation and is uniformly filled in a fibrous material substrate by heat-sensitive coagulation. In addition, the fiber sheet-like composite having the same feeling as that of the solvent system, that is, fullness and firmness, is composed of 1) an aqueous urethane resin having a heat-sensitive coagulation temperature of 40 to 90 ° C., and 2) an associative thickener. , And 3) can be realized only by a combination of heat-sensitive coagulation with steam, and the object of the present invention will not be achieved if any one of these components is missing.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The aqueous urethane resin of the present invention is required to have a thermosetting temperature of the resin itself (stock solution) of 40 to 90 ° C. The above refers to the temperature at which the entire aqueous urethane resin loses fluidity and solidifies. When the heat-sensitive coagulation temperature is lower than 40 ° C., the stability of the resin itself is poor, and there are problems such as generation of agglomerates in a compounding bath during processing in summer, gelation, and the like. In addition, the coagulability is not sharp, and not only is it difficult to uniformly fill the fiber with the resin, but also steam must be used at a high temperature and a high pressure. A more preferred thermosetting temperature is 4
5 to 80 ° C.

The aqueous urethane resin may be prepared by any known method, for example, a method of emulsifying and dispersing a urethane resin using a nonionic emulsifier having a specific HLB, a method of emulsifying and dispersing a nonionic emulsifier having a specific HLB. A method of emulsifying and dispersing a urethane prepolymer having a terminal isocyanate group and elongating the chain with a polyamine, a method of copolymerizing polyethylene glycol described in JP-A-57-39286, and an aqueous urethane resin containing a heat-sensitive coagulant. No.

The diisocyanate used for producing the aqueous urethane resin of the present invention includes, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4 '. -Diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate,
3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4 '
-Biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate,
1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine Diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate, and the like.

The active hydrogen-containing compound capable of reacting with an isocyanate group used in the production of the aqueous urethane resin of the present invention is preferably an average molecular weight of 300 to 10,000.
It is divided into a high molecular weight active hydrogen-containing compound having a molecular weight of 0, more preferably 500 to 5,000, and a low molecular weight active hydrogen-containing compound having an average molecular weight of 300 or less.

The high molecular weight active hydrogen-containing compounds include, for example, polyester polyols, polyether polyols, polycarbonate polyols, polyacetal polyols, polyacrylate polyols, polyesteramide polyols, polythioether polyols and the like.

As the polyester polyol, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol,
1,6-hexanediol, neopentyl glycol,
Diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (molecular weight 300 to 6,000), dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, glycol components such as hydroquinone and their alkylene oxide adducts, and succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid Acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4
-Naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-p, p'-dicarboxylic acid and the dicarboxylic acids Anhydrides or ester-forming derivatives; other polyesters obtained by a dehydration condensation reaction from acid components such as p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid and ester-forming derivatives of these hydroxycarboxylic acids. And polyester polyols obtained by a ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone, and copolymerized polyester polyols thereof.

Examples of the polyether polyol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5 pentanediol, and 1,6-hexane. Diol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, sorbitol,
Sucrose, aconit sugar, trimellitic acid, hemmellitic acid, phosphoric acid, ethylenediamine, diethylenetriamine,
At least two active hydrogen atoms such as triisopropanolamine, pyrogallol, dihydroxybenzoic acid, hydroxyphthalic acid, 1,2,3-propanetrithiol;
A compound obtained by subjecting one or more monomers such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexylene to addition polymerization by a conventional method using one or more compounds having two or more compounds as initiators. Or those obtained by ring-opening polymerization of the above monomers using a cationic catalyst, a protonic acid, a Lewis acid, or the like as a catalyst.

As the polycarbonate polyol,
1,4-butanediol, 1,5-pentanediol,
Compounds obtained by reacting glycols such as 1,6-hexanediol and diethylene glycol with dimethyl carbonate, diethyl carbonate, ethylene carbonate, diphenyl carbonate and phosgene are exemplified.

The low-molecular-weight active hydrogen-containing compound is a compound having a molecular weight of 300 or less and containing at least two or more active hydrogens, for example, a glycol component used as a raw material of a polyester polyol; glycerin, trimethylolethane , Trimethylolpropane,
Sorbitol, polyhydroxy compounds such as pentaerythritol and the like, in addition to this, further ethylenediamine,
1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2-methylpiperazine, 2,5-
Dimethylpiperazine, isophoronediamine, 4,4'-
Dicyclohexylmethanediamine, 3,3′-dimethyl-4,4′-dicyclohexylmethanediamine, 1,2
-Cyclohexanediamine, 1,4-cyclohexanediamine, aminoethylethanolamine, hydrazines, acid hydrazides, polyamines such as diethylenetriamine and triethylenetetramine.

The aqueous urethane resin of the present invention is not particularly limited in terms of composition and structure except that the heat-sensitive coagulation temperature is 40 to 90 ° C., and a urethane resin having a linear or branched structure can be used. Particularly preferred in the present invention are urethane resins having a branched structure. The concentration of the branch is preferably from 0.01 to 0.8 mol per kg of the urethane resin solid content. Branch concentration is 0.
If less than 01 mol, there is a problem in the durability in the ultra-fine process especially when using a non-woven fabric of ultra-fine fibers for artificial leather, heat resistance of the finally obtained artificial leather, moist heat resistance, light resistance, It is not preferable because various durability such as hydrolysis resistance is inferior. When the branching concentration is more than 0.8 mol, the microporous layer formed by steam coagulation has extremely poor film-forming properties, which causes problems such as insufficient mechanical strength such as flexibility. Not preferred. More preferably, it is 0.02 to 0.3 mol. Raw materials used to obtain such a branched structure include the above-mentioned trifunctional or higher-functional polyols, polyamines, and polyfunctional polyisocyanates obtained by modifying the diisocyanate by a known technique.

As the emulsifier having a specific HLB used in the production of the aqueous urethane resin of the present invention, HLB is 1
Nonionic emulsifiers having 0 to 18 are preferred. The term “HLB” as used herein refers to the HLB of the entire nonionic emulsifier to be finally used. When a plurality of nonionic emulsifiers are used, the HLB is obtained by weighting the HLB of the emulsifiers.

Further, in the method for producing a fibrous sheet-like composite of the present invention, particularly an artificial leather, the aqueous resin composition uniformly filled in the fibrous material substrate by steam coagulation forms a microporous layer after drying, Moreover, to give a texture equivalent to that of the solvent system, that is, a feeling of fulfillment and a firm texture,
In particular, it is preferable to use a nonionic emulsifier having a skeleton represented by the following structural formula (I).

Embedded image Ra-Ph- (I) R: an alkyl group, an aryl group or an alkylaryl group having 1 to 9 carbon atoms a: an integer of 1 to 3 Ph: phenyl ring residue

Specifically, polyoxyethylene alkylphenyl ethers such as polyoxyethylene nonyl phenyl ether, polyoxyethylene dinonyl phenyl ether, polyoxyethylene octyl phenyl ether, and polyoxyethylene dioctyl phenyl ether; Polyoxyethylene styrenated phenyl ethers including styrenated phenyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene tristyrenated phenyl ether and mixtures thereof; polyoxyethylene benzyl such as polyoxyethylene tribenzyl phenol ether Phenol ethers may be used, and these may be used alone or in combination. The amount of the emulsifier is not particularly limited, but is usually 1 to 20% by weight, more preferably 2 to 10% by weight, based on the solid content of the urethane resin.

Further, other emulsifiers may be used in combination as long as the effects of the present invention are not impaired. Examples of such emulsifiers include polyoxyethylene long-chain alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene sorbitol tetraoleate; and polyoxypropylene / polyoxyethylene. Glycol block or random polymer, polyamine polyoxypropylene / polyoxyethylene adducts, etc .; fatty acid salts such as sodium oleate, alkyl sulfate salts, alkyl benzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, alkane sulfones Phonate sodium salt,
Anionic emulsifiers such as sodium alkyldiphenyl ether sulfonate; and nonionic anionic emulsifiers such as polyoxyethylene alkyl sulfate and polyoxyethylene alkylphenyl sulfate.

In order to obtain the aqueous urethane resin of the present invention, a hydrophilic component can be introduced into the urethane resin in addition to the emulsifier, and a nonionic hydrophilic group is particularly preferred as the hydrophilic component. As a raw material used for introducing such a nonionic hydrophilic group, a group having at least one or more active hydrogen atoms in the molecule and comprising an ethylene oxide repeating unit, an ethylene oxide repeating unit and another alkylene A nonionic compound containing a group consisting of an oxide repeating unit is exemplified.

In the aqueous urethane resin of the present invention, particularly preferred nonionic hydrophilic group-containing compounds include (A)
It is a polyoxyalkylene glycol containing at least 50% by weight or more of ethylene oxide repeating units and / or (B) a polyoxyalkylene glycol at one end containing at least 50% by weight or more of ethylene oxide repeating units.

Examples of the polyoxyalkylene glycol (A) and the polyoxyalkylene glycol (B) at one end include polyethylene glycol, block or random type polyoxyethylene-polyoxypropylene copolymer glycol, polyoxyethylene-polyoxyglycol. Examples thereof include butylene copolymer glycol, polyoxyethylene-polyoxyalkylene copolymer glycol, and monoalkyl ethers such as methyl ether, ethyl ether and butyl ether. The content of the polyoxyalkylene glycol (A) and the polyoxyalkylene glycol (B) at one end is preferably 1 to 10% by weight in the solid content of the urethane resin obtained in the present invention.

The water-based urethane resin having a specific heat-sensitive coagulation temperature used in the present invention is basically preferably a nonionic water-based urethane resin, as described above. An aqueous urethane resin containing a heat-sensitive coagulant can also be used for imparting water. Examples of such an aqueous urethane resin include, in addition to the nonionic aqueous urethane resin described above, those further containing a carboxyl group as a hydrophilic component in the urethane resin skeleton.

As a raw material used for introducing such a carboxyl group, for example, at least one
Compounds having at least one active hydrogen atom and containing at least one carboxyl group are exemplified. Such carboxyl group-containing compounds include, for example, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, dioxymaleic acid, 2,6 And carboxylic acid-containing compounds such as -dioxybenzoic acid and 3,4-diaminobenzoic acid, and derivatives thereof, and polyester polyols obtained by copolymerizing them. Bases used to neutralize these carboxyl groups include, for example, non-volatile bases such as sodium hydroxide and potassium hydroxide; tertiary amines such as trimethylamine, triethylamine, dimethylethanolamine, methyldiethanolamine and triethanolamine. And volatile bases such as ammonia.

The content of the carboxyl group is from 0 to 1 as an acid value in the finally obtained urethane resin solid content.
5, preferably 1-10. When the acid value exceeds 15, it is not preferable because sufficient heat-sensitive gelling property cannot be obtained, the blending stability becomes unstable, and the durability such as water resistance decreases.

The heat-sensitive coagulant used in the present invention includes sodium silicofluoride, potassium silicofluoride; hydrochloric acid, nitric acid,
Ammonium salts of sulfuric acid, phosphoric acid, polyvalent metal salts such as sodium, potassium, calcium, magnesium, zinc, barium, nickel, tin, lead, iron and aluminum;
Polymer compounds having a methyl ether group soluble in cold water and insoluble in warm water, such as cellulose methyl ether and polyvinyl methyl ether; polyether thioether glycols, polyether-modified polydimethylsiloxane compounds; alkylphenol-formalin condensate Alkylene oxide adduct or JP-A-51-
No. 127142, JP-A-51-63841, and polyether-urethanes described in JP-A-60-65015 can be used, and these can be used alone or in combination.

The heat-sensitive coagulant may be added during or after the production of the aqueous urethane resin, or may be added and blended together with the associative thickener.

The urethane resin and urethane prepolymer containing an isocyanate group at the terminal according to the present invention are produced by a conventionally known method. For example, the diisocyanate and an active hydrogen-containing compound (including a hydrophilic component) are converted into an isocyanate group and an active hydrogen group. In the case of a urethane resin, the equivalent ratio is preferably 0.8: 1 to 1.2: 1, more preferably 0.9: 1 to 1.1: 1. In the case of a polymer, it is preferably 1.1: 1 to 3: 1, more preferably 1.2: 1 to 1.
The reaction is carried out at a ratio of 2: 1, preferably at 20 to 120C, more preferably at 30 to 100C.

These reactions can be carried out in the absence of a solvent, but an organic solvent can also be used for the purpose of controlling the reaction of the reaction system or reducing the viscosity. Examples of the organic solvent include, but are not limited to, aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; acetates such as ethyl acetate and butyl acetate; dimethylformamide; Examples thereof include amides such as -methylpyrrolidone, and it is preferable to use one having a relatively low boiling point that is easily removed by distillation.

The thus obtained urethane resin or urethane prepolymer having a terminal isocyanate group is dispersed in water by a conventionally known method using the nonionic emulsifier. When a urethane prepolymer having a terminal isocyanate group is used, after being dispersed in water, the chain is extended with the polyamine or water.

When a carboxyl group is introduced as a hydrophilic component into the urethane resin or the urethane prepolymer containing an isocyanate group at the terminal, the neutralizing agent is used before, during, after the urethanization reaction or when dispersing in water. Neutralized and dispersed in water.

When an organic solvent is used for the reaction, the aqueous urethane resin thus obtained is finally removed by distillation under reduced pressure or the like to obtain an aqueous urethane resin containing substantially no organic solvent. Used.

In producing the aqueous urethane resin of the present invention, in addition to water, other aqueous dispersions and aqueous dispersions, for example, vinyl acetate and ethylene acetate, may be used as long as the effects of the present invention are not impaired. Emulsions such as acrylic, acrylic, styrene, etc .; latexes, such as styrene / butadiene, acrylonitrile / butadiene, acrylic / butadiene; ionomers, such as polyethylene, polyolefin, etc .; various types of polyurethane, polyester, polyamide, epoxy resins, etc. An aqueous dispersion and an aqueous dispersion may be used in combination.

The aqueous urethane resin obtained by removing the organic solvent is a substantially solvent-free aqueous dispersion having a solid content of about 10 to 60% by weight, preferably 15 to 50% by weight. However, even when the organic solvent having a boiling point of 100 ° C. or more must be used for the production of the aqueous urethane resin, the use amount of such an organic solvent should be stopped up to 20% by weight based on the total weight of the aqueous dispersion. is there.

The associative thickener used in the present invention imparts sharp heat-sensitive coagulability in steam coagulation and, after the water-based resin composition uniformly filled in the fibrous material substrate by the heat coagulation is dried, has a microscopic coagulability. It is an essential component for forming a porous layer and obtaining a feeling equivalent to that of a solvent system, that is, a feeling of fulfillment and a firm feeling. Such associative thickeners are known and are described, for example, in JP-A-54-80349.
No., JP-A-58-213074, JP-A-60-4
No. 9022, Japanese Patent Publication No. 52-25840,
And urethane-based associative thickeners described in JP-A-67563 and JP-A-9-71766;
No. 2879, an associative thickener obtained by copolymerizing a nonionic urethane monomer described in JP-A-10-12030 with another acrylic monomer as an associative monomer,
Alternatively, an association-type thickener having an aminoplast skeleton described in WO96404015 can be used.

Specific examples of these associative thickeners include, for example, RHEOLATE 216, available from RHEOX.
266, Sc from Bernd Schwegmann
hwego Pur8020, Pur8050, MUN
Tafig made by ZING CHEMIE GMBH
l PUR40, PUR45, PUR60, Collacral PU85 from BASF, B from Hoechst
ORCHIGEL L75N, Primal QR-708, RM-825, RM manufactured by Rohm and Haas
-870, RM-1020, RM-2020 NPR, S
CT-200, SCT-270, RM-8W, RM-
4, TT-935, DK Thickener SCT-275 manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Adekanol UH-42 manufactured by Asahi Denka Co., Ltd.
0, UH540, UH-550, UH-750, SN Thickener 603,612, A-80 manufactured by San Nopco.
3, A-812, A-814, Sanyo Kasei's Eleminol N62, screw riser AP-2, Sud-Chem
IE OPTIFLO L150, M210, H4
00 and the like.

Among these associative thickeners, urethane-based associative thickeners having a hydrophobic group at the terminal and containing a urethane bond in the molecular chain are particularly preferred. And a reaction mixture thereof.

(II) R1-X- (PEG-X-R2-X) m-
PEG-X-R1 '(R1, R1': an alkyl group having 8 to 36 carbon atoms or a hydrocarbon group having an aromatic ring, wherein R1 and R1 'may be the same or different; R2: carbon number excluding NCO group 6 to 36 diisocyanate residues, X: urethane bond, PEG: polyethylene glycol residue having a molecular weight of 1,500 to 33,000, m: an integer of 0 or more)

(III) R1-YR2- (X-PEG-XR
3) m-X-PEG-X-R2-Y-R1 '(R1, R1': an alkyl group having 8 to 36 carbon atoms or a hydrocarbon group having an aromatic ring, even if R1 and R1 'are the same or different Good, R2, R3: 6 to 3 carbon atoms excluding NCO group
R2 and R3 may be the same or different in the diisocyanate residue of No. 6, X: urethane bond, Y: urethane bond or urea bond, PEG: molecular weight of 1,500 to 33,
000 polyethylene glycol residues, m: an integer of 0 or more)

(IV) R1- (OA) p-X-R2- (X-PE
G—X—R 3) m—X— (AO) q—R 1 ′ (R 1, R 1 ′: an alkyl group having 8 to 36 carbon atoms or a hydrocarbon group having an aromatic ring, wherein R 1 and R 1 ′ are the same or different. R2, R3: 6 to 3 carbon atoms excluding NCO group
R 2 and R 3 may be the same or different in a diisocyanate residue of 6, X: urethane bond, A: a hydrocarbon residue having at least ethylene with a hydrocarbon having 2 to 4 carbon atoms,
m: an integer of 0 or more, p and q: p and q are integers of 1 to 200
May be the same or different)

[0047] (R1, R1 ', R1 ": an alkyl group having 8 to 36 carbon atoms or a hydrocarbon group having an aromatic ring, wherein R1, R1' and R1" may be the same or different. R4: Excluding NCO group Functional polyisocyanate residue, A: hydrocarbon residue having at least ethylene with a hydrocarbon having 2 to 4 carbon atoms, X: urethane bond, i, j, k: an integer of 0 or more and (i + j)
+ K) is an integer of 3 or more, p, q, r: an integer of 1 to 200, and p, q and r may be the same or different)

[0048] (R1, R1 ', R1 ": an alkyl group having 8 to 36 carbon atoms or a hydrocarbon group having an aromatic ring, wherein R1, R1' and R1" may be the same or different. R4: Excluding NCO group A functional polyisocyanate residue, A: a hydrocarbon residue having at least ethylene with a hydrocarbon having 2 to 4 carbon atoms, X: a urethane bond, Y: a urethane bond or a urea bond,
i, j, k: an integer of 0 or more and (i + j + k) is an integer of 3 or more, p, q: an integer of 1 to 200, and p and q may be the same or different.

[0049] (R1, R1 ', R1 ": an alkyl group having 8 to 36 carbon atoms or a hydrocarbon group having an aromatic ring, wherein R1, R1' and R1" may be the same or different, and R5 is a group other than active hydrogen. Functional polyol or polyamine residue, A: carbon number 2
To 4 hydrocarbon residues containing at least ethylene, X: urethane bond, i, j, k: integers of 0 or more and (i + j + k) being 3 or more, p, q, r: 1-2
An integer of 00, p, q and r may be the same or different)

The amount of the associative thickener used is 0.1 to 20 parts by weight based on 100 parts of the aqueous urethane resin in terms of solid content.
Parts are required, preferably 0.3 to 10 parts. When the use amount of the associative thickener is less than 0.1 part, sharp heat-sensitive coagulability is not obtained in heat-sensitive coagulation by steam, and after the water-based resin composition filled in the fiber material substrate by heat-sensitive coagulation is dried, A microporous layer is not formed, and a feeling of fulfillment and firmness equivalent to that of a solvent system cannot be obtained. Conversely, when the amount exceeds 20 parts, the feeling of fulfillment is improved, but the texture becomes too hard, and the water resistance is lowered, which is not suitable.

Thus, the aqueous resin composition (a) of the present invention can be obtained by mixing 1) an aqueous urethane resin having a heat-sensitive coagulation temperature of 40 to 90 ° C. and 2) an associative thickener at a temperature higher than that of the aqueous urethane resin. At a low temperature, and by adding and thoroughly mixing. Alternatively, the associative thickener can be added and compounded during the production of the aqueous urethane resin. However, in this case, it goes without saying that the production is carried out at a temperature sufficiently lower than the heat-sensitive coagulation temperature of the aqueous urethane resin containing the associative thickener.

Such an aqueous resin composition is used as it is, or as long as it does not inhibit the formation of the microporous layer, and other aqueous dispersions, for example, emulsions of vinyl acetate, ethylene vinyl acetate, acrylic, acrylic styrene and the like; styrene・
Butadiene-based, acrylonitrile-butadiene-based, acrylic-butadiene-based latex; polyethylene-based,
Polyolefin-based ionomers; polyurethane, polyester, polyamide, and epoxy-based aqueous dispersions can be blended and used in an arbitrary ratio.

In addition to the above aqueous dispersion, a film-forming auxiliary such as an alkylene glycol derivative or a dialkyl ester of an aliphatic dicarboxylic acid or N-methylpyrrolidone for the purpose of improving the film-forming properties, and improving the processability. For the purpose, a fluorine-based leveling agent, an emulsifier such as a dialkylsulfosuccinate-based compound, various leveling agents such as an acetylene glycol derivative, and a penetrant may be blended. Also, for the purpose of suppressing foaming of the blended liquid, mineral oils, amides,
It is also possible to mix various antifoaming agents such as silicones or a small amount of alcohols such as ethanol and isopropyl alcohol.

For the purpose of coloring, various water-soluble or water-dispersible inorganic and organic pigments can be added. Inorganic fillers such as calcium carbonate, talc, aluminum hydroxide and silica, cellulose powder, protein powder, Organic fillers such as silk powder and organic short fibers can also be blended. For the purpose of improving various durability such as light resistance, heat resistance, water resistance and solvent resistance of the above aqueous dispersion, a stabilizer such as an antioxidant, an ultraviolet absorber and a hydrolysis inhibitor is used to produce an aqueous urethane resin. A crosslinking agent such as an epoxy resin, a melamine resin, an isocyanate compound, an aziridine compound, a polycarbodiimide compound, and an oxazoline compound may be added during or after the process, or may be used in combination therewith.

The (a) water-based resin composition used in the present invention finally has a resin solid content of 5 to 50% by weight, preferably 1 to 50% by weight.
After being adjusted to 0 to 40% by weight, the fibrous material substrate is impregnated or applied, and thermally solidified with steam.

As the fiber material substrate (b) that can be used in the present invention, any nonwoven fabric or knitted fabric conventionally used in the production of fiber material substrates can be used without any particular limitation. The nonwoven fabric may be a nonwoven fabric in which a woven fabric or the like is laminated inside or on the surface for the purpose of reinforcement or the like. Constituent fibers may be any of natural fibers and chemical fibers, as natural fibers are cotton, wool, silk, asbestos, etc., as chemical fibers are rayon, regenerated fibers such as Tencel, acetate, semi-synthetic fibers such as triacetate, polyamide, Examples include synthetic fibers such as polyester, polyolefin, and acrylic. It is also possible to appropriately use a fiber obtained by mixing these. In order to obtain a fiber sheet composite having a good texture, it is desirable to use ultrafine fibers. The ultrafine fiber may be any of a sea-island type, a split or peeling type, a straight spinning type, and the like. Examples of the method for ultrafine-sealing the sea-island fiber include dissolution by solvent treatment with toluene or the like, decomposition by an alkali, or the like. There is no particular limitation.

The method of impregnating and applying the aqueous resin composition of the present invention to the fiber material substrate may be any method as long as it is a usual method, for example, impregnation with a mangle, knife coater, roll coater, air knife coater. And a spray coater. In the case of impregnation, the adhesion amount (solid content) of the urethane resin is preferably 3 to 100 parts by weight based on 100 parts by weight of the fiber material base. In the case of coating, the coating thickness is preferably 0.1 to 10 mm. It is also preferable to carry out application after impregnation for the purpose of suppressing fluff on the surface of the fibrous sheet-like composite obtained by the present invention and imparting surface smoothness and cushioning properties.

At the time of this impregnation or coating, a foaming agent such as ammonium stearate, a metal salt of a higher fatty acid, or a dialkyl sulfosuccinate emulsifier is added to the aqueous resin composition (A) of the present invention. It can also be processed. In particular, in the case of the coating process, it is possible to form a foam layer having a good cushioning property, and even in the case of the impregnation process, it is possible to obtain a very soft feeling with a small amount of adhesion.

The heat-sensitive coagulation by steam of the present invention can be processed if the temperature of the steam is equal to or higher than the heat-sensitive gelation temperature of the water-based resin composition. The temperature is preferably set to 10 ° C. or more of the thermal gelation temperature, and the steam temperature is usually 60 to 140 ° C. In view of economy and efficiency, a steam temperature of 70 to 120C is particularly preferable. Further, as the humidity approaches 100%, drying from the surface is suppressed, which is preferable. The steam treatment time is usually several seconds to 30 minutes, and more preferably 10 seconds to 20 minutes. It is also possible to use steam coagulation in combination with other methods. As another method, for example, a coagulation method such as infrared rays, electromagnetic waves, and high frequencies can be used.

The work cloth steam-coagulated by the method of the present invention is then dried by heating. As the method, for example, hot air heating, infrared heating, electromagnetic wave heating, high-frequency heating,
Any drying method such as cylinder heating can be used, but generally, hot air heating with low capital investment and running cost is preferable. The drying temperature is such that the work cloth does not deteriorate or deteriorate due to heat, and it is sufficient that the aqueous resin composition in the fibrous material substrate is sufficiently dried to form a film.
0 ° C.

The fiber sheet composite obtained by the present invention may be subjected to washing extraction (soaping) of the fiber sheet composite obtained by the above method with warm water or hot water as a post-treatment. By this soaping process,
The nonionic emulsifier contained in the aqueous urethane resin of the present invention, the inorganic salts used for the purpose of accelerating the heat-sensitive coagulation, the heat-sensitive coagulant and the like are extracted and removed, and the microporous structure of the fiber sheet-like composite finally obtained is obtained. This is preferable because not only the fineness becomes finer, but also various durability such as light resistance and heat and humidity resistance of the fiber sheet composite is improved. Further, such a soaping step can also be used as a step of dyeing a fiber sheet-like composite or a step of ultra-fineness when using ultra-fine fibers.

When such a soaping step is taken,
In particular, for the purpose of making the microporous structure finer, a water-soluble polymer such as poval or gelatin may be added as long as the heat-sensitive coagulability of the present invention is not impaired.

The fibrous sheet-like composite thus obtained according to the present invention includes various synthetic leathers such as shoes, bags, clothing, furniture such as chairs and sofas, interior materials for automobiles such as vehicle seats and handles, and moisture-permeable and waterproof materials. It is used for artificial leather, abrasives, felt pen cores, etc., and is particularly useful for artificial leather.

The fibrous sheet-like composite of the present invention can be used as it is for the above-mentioned applications. However, if necessary, an intermediate foam layer, a skin / adhesive layer, etc. may be further provided to produce artificial leather with silver. It is an aspect. Alternatively, it is also possible to use only a surface treatment coat. Furthermore, it is also possible to subject these artificial leathers to surface finishing treatment, kneading and the like.

[0065]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples. Parts in Examples are parts by weight.

[Synthesis Example of Aqueous Polyurethane Resin] (Synthesis Example A) 500 parts of polytetramethylene glycol having a molecular weight of 1,300 and 1,4-butanediol 15.3
Parts, 11.1 parts of trimethylolpropane, molecular weight 600
39.4 parts of polyethylene glycol and 223.4 parts of isophorone diisocyanate in methyl ethyl ketone 425
In the presence of 0.2 parts of dibutyltin dilaurate
The reaction was carried out at 70 ° C. until O% reached 1.8% to obtain a urethane prepolymer having terminal isocyanate groups. This urethane prepolymer was mixed with 1239 parts of an aqueous emulsifier solution in which 55.2 parts of polyoxyethylene distyrenated phenyl ether (HLB = 14) was dissolved and emulsified and dispersed by a homomixer. Then, 22 parts of anhydrous piperazine was dissolved. The chain was extended by adding 220 parts of the aqueous solution of the chain extender.
Then, methyl ethyl ketone was distilled off under reduced pressure to obtain a solid matter of 40%.
% Of aqueous urethane resin A was obtained. The heat-sensitive coagulation temperature of this aqueous polyurethane resin was 52 ° C.

(Synthesis Example B) 1,4- having a molecular weight of 1,000
500 parts of a butanediol / adipic acid polyester,
18.5 parts of 1,4-butanediol / adipic acid polyester having a molecular weight of 2,000, 16.5 parts of trimethylolpropane, 34.1 parts of polyethylene glycol monomethyl ether having a molecular weight of 1,000 and 4,4'-diphenylmethane diisocyanate 284.6 parts of toluene 36
In 6 parts, the mixture was reacted at 80 ° C. until the NCO% reached 2.9% to obtain a urethane prepolymer having terminal isocyanate groups. This urethane prepolymer was obtained by mixing 42.7 parts of polyoxyethylene nonyl phenyl ether (HLB = 16) and polyoxyethylene nonyl phenyl ether (HLB).
= 12) After mixing with 939 parts of an emulsifier aqueous solution in which 42.7 parts were dissolved and emulsifying and dispersing with a homomixer, 330 parts of an aqueous solution of a chain extender in which 33 parts of anhydrous piperazine were dissolved was added to perform chain elongation. I let you. Then, toluene was distilled off under reduced pressure to obtain an aqueous urethane resin B having a solid content of 50%. The heat-sensitive coagulation temperature of this aqueous polyurethane resin was 60 ° C.

Example 1 An aqueous solution prepared by diluting 2 parts of eleminol N62 (manufactured by Sanyo Kasei Co., Ltd.) as an associative thickener with 48 parts of water in advance was mixed with 50 parts of an aqueous urethane resin A. An aqueous resin composition having a resin concentration of 20% was prepared. This aqueous resin composition was impregnated into a nonwoven fabric made of polyester fiber and having a basis weight of 300 g / m ² , and squeezed with a mangle so that the wet pickup became 250%. Then, it is left still in saturated steam at 100 ° C. for 2 minutes.
It was dried in a dryer at 0 ° C. for 20 minutes.

Example 2 Processing was performed in the same manner as in Example 1 except that the water-based urethane resin B was used.

Example 3 Processing was carried out in the same manner as in Example 1 except that Primal RM-8W (manufactured by Rohm and Haas) was used as the associative thickener.

Example 4 Processing was performed in the same manner as in Example 1 except that Primal RM-2020NPR (manufactured by Rohm and Haas) was used as the associative thickener.

(Example 5) Processing was performed in the same manner as in Example 1 except that ADECANOL UH-420 (manufactured by Asahi Denka Co., Ltd.) was used as the associative thickener.

Example 6 COLL as an associative thickener
Processing was performed in the same manner as in Example 1 except that ACRAL PU-85 (manufactured by BASF) was used.

Example 7 BORC as an associative thickener
Processing was performed in the same manner as in Example 1 except that HGEL L75N (manufactured by Hoechst) was used.

(Comparative Example 1) Processing was performed in the same manner as in Example 1 except that Bondic 1850NS (manufactured by Dainippon Ink & Chemicals, Inc., heat-sensitive coagulation temperature of 100 ° C or higher) was used as an aqueous urethane resin.

(Comparative Example 2) Processing was carried out in the same manner as in Example 1 except that no associative thickener was added.

Comparative Example 3 Two parts of Boncoat HV (manufactured by Dainippon Ink and Chemicals, Inc.), which is an alkali-soluble acrylic thickener, were added to 50 parts of an aqueous urethane resin A in advance with 4 parts of water.
An aqueous resin composition was prepared by diluting and dissolving with 7 parts and further adding 1 part of 28% aqueous ammonia to increase the viscosity to prepare an aqueous resin composition. Thereafter, the same processing as in Example 1 was performed.

(Comparative Example 4) The aqueous resin composition of Example 1 was impregnated into a nonwoven fabric made of polyester fiber and having a basis weight of 300 g / m ² , and was squeezed with a mangle to a wet pickup of 250%. Then, it was left still in a dryer at 150 ° C. for 2 minutes, and then dried in a dryer at 100 ° C. for 20 minutes. The results of these evaluations are shown in the following table.

[0079]

[Table 1]

[0080]

[Table 2]

[0081]

[Table 3]

<Evaluation method> Presence / absence of miculation: The filled state of the urethane resin was visually observed by an electron micrograph of a cross section of the work cloth. <Judgment> ○: Uniformly filled state without microphone ×: Unevenly filled state with microphone

Presence / absence of microporous: An electron micrograph of a cross section of the work cloth was used to visually observe whether or not the surface of the filled urethane resin was microporous. <Judgment> ○: With microporous ×: Without microporous

Work cloth feeling: Work cloth was evaluated by touch. <Judgment> ：: Both waist feeling and fulfillment feeling are particularly excellent. ○: There is a feeling of waist, there is a sense of fulfillment △: There is a little inferior to the feeling of waist and fulfillment ×: There is no feeling of waist and feeling of fulfillment

From the above Examples and Comparative Examples, the water-based resin composition uniformly filled between the fibers by thermal coagulation forms a microporous layer after drying, and has the same feeling as that of the solvent system, that is, fullness. The fibrous sheet-like composite giving a stiff texture includes (a) an aqueous resin composition comprising 1) an aqueous urethane resin having a specific heat-sensitive coagulation temperature and 2) an associative thickener, and (b) a fiber material. Impregnated or coated on the substrate,
(C) It can be realized only by a combination of coagulation with steam, and it has been confirmed that the object of the present invention will not be achieved if any one of these components is missing.

[0086]

The fibrous sheet-like composite thus obtained according to the present invention has a sharp thermocoagulability in thermocoagulation by steam, and therefore has no migration.
The aqueous resin composition is uniformly filled in the fiber material base material, and after drying, the aqueous resin composition forms a microporous layer, and gives a texture equivalent to that of the solvent system, that is, a fullness and a firm texture. It has an extremely excellent feature.

[0087]

[Brief description of the drawings]

FIG. 1 is a photomicrograph (500 ×) of a cross section of a fiber sheet composite in Example 1, which shows that a water-based urethane resin forms a microporous structure.

Claims (9)

[Claims] 1. (a) 1) The heat-sensitive coagulation temperature is 40 to 90 ° C.
(B) impregnating or applying a water-based resin composition comprising a water-based urethane resin and 2) an associative thickener to a fiber material substrate, and (c) heat-sensitive coagulation with steam. A method for producing a composite. 2. The method according to claim 1, wherein the aqueous urethane resin is HLB 10-1.
The method for producing a fibrous sheet-like composite according to claim 1, wherein the composite is dispersed with the nonionic emulsifier of No. 8. 3. The nonionic emulsifier has the following structural formula (I):
Having a skeleton represented by the formula: Ra-Ph- (I) R: an alkyl group, an aryl group or an alkylaryl group having 1 to 9 carbon atoms a: an integer of 1 to 3 Ph: a phenyl ring residue The method for producing a fibrous sheet-like composite according to any one of claims 1 to 2, wherein: 4. The associative thickener according to claim 1, wherein the associative thickener has a hydrophobic group at a terminal and a urethane bond in a molecular chain. A method for producing a fiber sheet composite. 5. One end containing at least 50% by weight or more of (A) a polyoxyalkylene glycol containing ethylene oxide repeating units and / or (B) at least 50% by weight of ethylene oxide repeating units in a molecular chain. 2. An aqueous urethane resin containing a polyoxyalkylene glycol.
5. The method for producing a fibrous sheet-like composite according to any one of items 4 to 4. 6. The method for producing a fiber sheet composite according to claim 1, wherein the temperature of the steam is 70 to 120 ° C. 7. The processing time by steam is 10 seconds to 2 seconds.
The method for producing a fiber sheet-like composite according to any one of claims 1 to 6, wherein the time is 0 minutes. 8. After heat-sensitive coagulation with steam, the mixture is further cooled to 8
The method for producing a fibrous sheet-like composite according to any one of claims 1 to 7, wherein the method is dried at a temperature of 0 to 150 ° C. 9. An artificial leather obtained by the production method according to claim 1.