JP2003336028A - Aqueous dry laminate adhesive composition for synthetic leather and method for manufacturing synthetic leather using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous dry laminate adhesive composition for a synthetic leather which (1) comprises an aqueous urethane resin comprising only a nonionic hydrophilic group as the essential hydrophilic ingredient, (2) is obtained by using no or little organic solvent but water, and (3) exhibits adhesive performances equal to those of a solvent-based adhesive, and to provide a method for manufacturing the synthetic leather using the adhesive composition, and the synthetic leather. <P>SOLUTION: The adhesive composition comprises the aqueous urethane resin (A), a crosslinking agent (B), a thickening agent (C), and an aqueous pigment (D), where the resin (A) contains as the essential hydrophilic group only a nonionic hydrophilic group and contains 1-30 pts.wt., based on 100 pts.wt. of the solid content of the urethane resin, of a nonionic hydrophilic group- containing compound linked to the molecule of the resin (A), the solid content of the urethane resin has a flow initiation temperature of 80°C or below, and the flow initiation temperature after the urethane resin is cured by a reaction with the crosslinking agent (B) is 120°C or higher. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aqueous adhesive composition suitable for producing synthetic leather, a method for producing synthetic leather using the same, and a synthetic leather obtained by the production method.
The term "synthetic leather" used in the present invention means fiber sheet materials such as woven and knitted fabrics and non-woven fabrics, and these fiber sheet materials are coated with an organic solvent-based or water-based resin, preferably urethane resin (foam coating). ) Or impregnated to form a porous layer, and further made of a natural leather material such as split leather.

[0002]

2. Description of the Related Art Conventional synthetic leather is manufactured by applying an organic solvent solution of a urethane resin on a release paper and drying it to form a skin layer, and then applying an organic solvent solution of the urethane resin on the skin layer. A wet laminating method in which an adhesive layer containing a cross-linking agent is applied to form an adhesive layer and then immediately bonded to a fiber substrate, or a dry laminating method in which the adhesive layer is once dried and then bonded to a fiber substrate Either method. In these production methods, several kinds of organic solvents are usually mixed and used, so it is extremely difficult to recover the organic solvent volatilized in the drying step, and most of them are released into the atmosphere or incinerated. Is the current situation.
There is also an example in which an organic solvent having a high boiling point such as dimethylformamide (DMF) is used, but in such a case, a part of the organic solvent remains on the synthetic leather even after drying, and its toxicity is a problem.

In order to solve these problems, various investigations have been made to change the urethane resin used from an organic solvent solution type to an aqueous type, but a synthetic leather still having satisfactory appearance and physical properties is obtained. Not obtained. The reason is that in a wet laminating method in which a thickening agent is added to an aqueous urethane resin that is usually used and then applied and laminated, the viscosity of the adhesive is thixotropic as compared with a solvent system, When laminated with constant pressure,
The adhesive easily penetrates into the fiber base material, it easily sticks out to the side of the base material, it dries slowly, and the evaporated water vapor migrates between the skin layer and the release paper, causing some skin layer to float. However, there is a problem that the quality, such as appearance, texture, and adhesive strength, of the skin layer of the finally obtained synthetic leather becomes poor. Further, there is a dry laminating method in order to avoid the above problems, but in the conventional water-based urethane resin, the film after drying has almost no tackiness, and it is necessary to laminate at a high temperature and a high pressure. There is a drawback in that a satisfactory performance cannot be obtained, such that the appearance of the layer becomes poor, or the foamed layer has a foamed layer and is crushed under high temperature and high pressure conditions to deteriorate the texture.

Further, as the water-based urethane resin adhesive, an anionic water-based urethane resin adhesive is proposed in Japanese Patent No. 2894449, but the anion-type water-based urethane resin adds an amine compound or an alkali metal to an anion group. Since the water dispersibility is imparted by forming a neutralized salt by this, the aqueous urethane resin dispersion becomes alkaline and the viscosity of the cross-linking agent blended liquid is increased because the reaction with the cross-linking agent used in combination is promoted. Viscosity decreases with time (hereinafter referred to as time-dependent viscosity decrease). Due to this phenomenon, it becomes difficult to control the coating thickness of the adhesive layer to be constant when manufacturing the artificial leather, and there is a problem that the quality such as the appearance, texture, and adhesive strength of the synthetic leather becomes poor. Further, when an acidic substance, a cationic substance, or the like is added as an additive, a shock is caused to cause problems such as increase in viscosity, aggregation / precipitation, and the additive used in combination is also limited.

[0005]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to contain no organic solvent or almost no organic solvent, and the adhesive composition after compounding with a cross-linking agent shows little decrease in viscosity over time, and is used in combination. Regarding the method for producing synthetic leather using an aqueous urethane resin having improved combined stability with an additive,
Anion type, cation type, using an aqueous urethane resin that does not contain any groups of amphoteric type and essentially requires only a nonionic hydrophilic group, uses water as a solvent, and even under a relatively low temperature atmosphere after drying. Has sufficient initial adhesion,
Provided is a water-based dry laminate adhesive composition for synthetic leather that exhibits adhesive performance equivalent to that of a solvent-based adhesive after lamination, and a method for producing synthetic leather using the adhesive composition, and a method for producing the same. The purpose is to provide synthetic leather.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that when a specific aqueous urethane resin, a crosslinking agent, a thickener, and an aqueous pigment are used, The inventors have found that the above problems can be solved and completed the present invention.

That is, the present invention provides an adhesive composition containing an aqueous urethane resin (A), a cross-linking agent (B), a thickener (C), and an aqueous pigment (D). ) Does not contain any of anion type, cation type and amphoteric type groups as hydrophilic groups bound in the molecule, and essentially contains only nonionic type hydrophilic groups, and nonionic type bound in the molecule of (A) The hydrophilic group-containing compound is contained in an amount of 1 to 30 parts by weight per 100 parts by weight of the urethane resin solid content, the outflow start temperature of the urethane resin solid content is 80 ° C. or lower, and the urethane resin reacts with the crosslinking agent (B). The present invention relates to a water-based dry laminate adhesive composition for synthetic leather, which has an outflow starting temperature of 120 ° C. or higher after being cured.

In the present invention, the above-mentioned water-based dry laminate adhesive composition for synthetic leather is applied on a skin layer previously formed on a release paper and dried to form an adhesive layer. The present invention relates to a method for producing synthetic leather, which comprises dry laminating an agent layer and a fiber base material.

The present invention also relates to a synthetic leather obtained by the above manufacturing method.

Further, the present invention relates to a synthetic leather obtained by using the above-mentioned aqueous dry laminate adhesive composition for synthetic leather.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, necessary items for carrying out the present invention will be specifically described below.

The aqueous dry laminate adhesive composition for synthetic leather (hereinafter referred to as the adhesive composition) of the present invention contains at least an aqueous urethane resin (A), a crosslinking agent (B), a thickener (C), and an aqueous solution. A pigment (D) is used.

Aqueous urethane resin (A) used in the present invention
As the polyisocyanate used for the production of, 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 can be mentioned. ,
Of these, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate are preferable in consideration of the raw material cost, and 1,6 to prevent photo-deterioration and thermal deterioration of the resulting aqueous urethane resin. -Hexamethylene diisocyanate, isophorone diisocyanate,
4,4'-dicyclohexylmethane diisocyanate is preferred.

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

Examples of the high molecular weight compound include polyester polyol, polyether polyol, polycarbonate polyol, polyacetal polyol,
Examples thereof include polyacrylate polyols, polyesteramide polyols, polythioether polyols, polybutadiene-based polyolefin polyols and the like. Examples of the polyester polyol include 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 30
0-6,000), dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene,
Glycol components such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, hydroquinone and their alkylene oxide adducts, and succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid Acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic 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 anhydrides or ester-forming derivatives of these dicarboxylic acids; p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid and ester-forming derivatives of these hydroxycarboxylic acids. In addition to the polyester obtained by the dehydration condensation reaction with the acid component of, the polyester obtained by the ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone, and a copolyester thereof. Examples of the polyether polyol include, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol,
1,3-butanediol, 1,4-butanediol,
1,6-hexanediol, neopentyl glycol,
Glycerin, trimethylolethane, trimethylolpropane, sorbitol, sucrose, aconit sugar, trimellitic acid, hemimellitic acid, phosphoric acid, ethylenediamine,
Diethylenetriamine, triisopropanolamine,
One or two of compounds having at least two active hydrogen atoms such as pyrogallol, dihydroxybenzoic acid, hydroxyphthalic acid, and 1,2,3-propanetrithiol.
Addition polymerization of one or more monomers such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, cyclohexylene, etc. using one or more as an initiator by a conventional method, or a cationic catalyst of the above monomer Ring-opening polymerized with a protonic acid, a Lewis acid or the like as a catalyst. Examples of the polycarbonate polyol include 1,4-butanediol and 1,6-
Examples thereof include compounds obtained by reacting glycols such as hexanediol and diethylene glycol with diphenyl carbonate and phosgene.

The low molecular weight compound has a molecular weight of 30.
A compound containing at least two active hydrogens in the molecule of 0 or less, for example, a glycol component used as a raw material of polyester polyol; polyhydroxy such as glycerin, trimethylolethane, trimethylolpropane, sorbitol, pentaerythritol Compound;
Ethylenediamine, 1,6-hexamethylenediamine,
Piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine,
Examples thereof include amine compounds such as 1,2-propanediamine, diethylenetriamine and triethylenetetramine, and hydrazines such as hydrazine and acid hydrazide.

Aqueous urethane resin (A) used in the present invention
Does not contain any of anionic, cationic and amphoteric groups as hydrophilic groups bonded in the molecule, and essentially contains only nonionic hydrophilic groups.

Aqueous urethane resin (A) used in the present invention
Examples of the nonionic hydrophilic group-containing compound used in the production of are a nonionic hydrophilic group-containing compound containing a group composed of ethylene oxide repeating units and other alkylene oxide repeating units. Examples of the nonionic hydrophilic group-containing compound include at least 30% by weight of ethylene oxide repeating units,
Polyoxyethylene glycol or polyoxyethylene-polyoxypropylene copolymer glycol or polyoxyethylene-polyoxy having a weight average molecular weight of at least one active hydrogen in the molecule is preferably in the range of 300 to 20,000. Butylene copolymer glycol,
Nonionic hydrophilic group-containing compounds such as polyoxyethylene-polyoxyalkylene copolymer glycol or its monoalkyl ether, or block polymerization type nonionic hydrophilic group-containing compounds obtained by adding ethylene oxide to the above-mentioned high molecular weight compounds. . As the hydrophilic component, the above compounds may be used alone or in combination of two or more kinds.

Aqueous urethane resin (A) used in the present invention
In order to stably produce the above, the nonionic hydrophilic group-containing compound bonded in the molecule is preferably in the range of 1 to 30 parts by weight, more preferably 2 parts by weight, per 100 parts by weight of the solid content of the urethane resin finally obtained. -20 parts by weight.

When the aqueous urethane resin (A) used in the present invention is produced, an external emulsifier may be used in combination with the hydrophilic component. As such an external emulsifier,
For example, polyoxyethylene nonyl phenyl ether,
Nonionic emulsifiers such as polyoxyethylene lauryl ether, polyoxyethylene styrenated phenyl ether and polyoxyethylene sorbitol tetraoleate;
Anionic emulsifiers such as fatty acid salts such as sodium oleate, alkyl sulfate ester salts, alkylbenzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, alkane sulfonate sodium salts, and alkyl diphenyl ether sulfonate sodium salts;
Nonionic anionic emulsifiers such as polyoxyethylene alkyl sulfates and polyoxyethylene alkylphenyl sulfates; cationic emulsifiers such as alkyl trimethyl ammonium salts; and fluorine-based and silicone-based special emulsifiers.

The method for producing the water-based urethane resin used in the present invention may be any conventionally known method and is not particularly limited, and examples thereof include the following methods. Method: Active hydrogen-containing compound, nonionic hydrophilic group-containing compound, and organic solvent solution or organic solvent dispersion of a nonionic hydrophilic group-containing urethane resin obtained by reacting with a polyisocyanate compound, water is mixed To obtain an aqueous dispersion. Method: An organic solvent solution or organic solvent dispersion of a nonionic hydrophilic group-containing terminal isocyanate group-containing urethane prepolymer obtained by reacting an active hydrogen-containing compound, a nonionic hydrophilic group-containing compound, and a polyisocyanate compound A method in which water is mixed and dispersed in water and then reacted with polyamine to obtain an aqueous dispersion. Method: An organic solvent solution or organic solvent dispersion of a nonionic hydrophilic group-containing terminal isocyanate group-containing urethane prepolymer obtained by reacting an active hydrogen-containing compound, a nonionic hydrophilic group-containing compound, and a polyisocyanate compound , A method of obtaining an aqueous dispersion by mixing with an aqueous solution containing a polyamine. However, in any of the above methods 1 to 3, an emulsifier may be further added in water or to a solution or dispersion of an organic solvent of urethane resin. These reactions can be carried out without using an organic solvent, but an organic solvent can also be used for the purpose of controlling the reaction of the reaction system or reducing the viscosity. The organic solvent is not particularly limited, and examples thereof include aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; acetic acid esters such as ethyl acetate and butyl acetate; N, N- Examples thereof include amides such as dimethylformamide and N-methyl-2-pyrrolidone. When such an organic solvent is distilled off from the finally obtained urethane resin aqueous dispersion, it is preferable to use one having a relatively low boiling point, which is easily removed by distillation. Even when it is unavoidable that an organic solvent having a boiling point of 100 ° C. or higher must be used, it is preferable to keep the amount used to the minimum necessary. The water-based urethane resin thus obtained is used by removing the organic solvent by distillation, if necessary, but may be used as it is. Various types of distillation apparatuses can be used for removing the organic solvent by distillation, but a distillation apparatus that does not release the distilled solvent and the organic solvent that has been distilled off to the atmosphere is preferable, and a thin-film evaporation apparatus is particularly preferable.

The aqueous dry laminating adhesive composition for synthetic leather of the present invention has a sufficient initial adhesiveness even in an atmosphere of relatively low temperature after drying, which is the object of the present invention, and is solvent-based after laminating. Aqueous urethane resin (A) and cross-linking agent (B) in order to develop adhesive performance equivalent to that of adhesive
In particular, the aqueous urethane resin (A) contains a nonionic hydrophilic group as an essential hydrophilic group which does not contain any groups of anionic type, cationic type and amphoteric type as a hydrophilic group bonded in the molecule. The content of the nonionic hydrophilic group-containing compound bound therein is preferably in the range of 1 to 30 parts by weight per 100 parts by weight of the urethane resin solids finally obtained, and the outflow starting temperature of the urethane resin solids is preferred. Is 80 ° C. or lower, and the outflow start temperature after the urethane resin reacts with the crosslinking agent (B) and is cured is preferably 120 ° C. or higher. More preferably, the outflow start temperature of the urethane resin solid content is 60 ° C. or lower, and the melt viscosity at 80 ° C. is 10 ⁵ Pa · s or lower. If the outflow starting temperature of the urethane resin solids and the melt viscosity at 80 ° C. satisfy such conditions, sufficient adhesiveness of the adhesive layer can be obtained when the synthetic leather is manufactured by laminating the skin layer and the fiber base material. As a result, sufficient wettability and initial adhesiveness to the skin layer or the fiber substrate which is the adherend can be obtained. In addition, the outflow starting temperature and the melt viscosity as used in the present invention are obtained by using a high-performance flow tester CFT-500D type manufactured by Shimadzu Corporation.
These are the outflow start temperature and the melt viscosity when measured at a temperature rising rate of 3 ° C./min using an orifice having a load of 30 kgf, an inner diameter of 1 mm and a length of 1 mm.

Aqueous urethane resin (A) used in the present invention
In order to make the outflow starting temperature of the urethane resin solid content of 80 ° C. or lower, a method of reducing the molecular weight of the aqueous urethane resin is effective, and the weight average molecular weight of the aqueous urethane resin is preferably 2,000 to 200. The range is 3,000, and more preferably the range is 3,000 to 100,000.

Further, the aqueous urethane resin (A) used in the present invention has an isocyanate group in the molecule of polyurethane in order to keep the outflow starting temperature after reacting with the crosslinking agent (B) and curing to 120 ° C. or more. It is preferable to contain at least two or more active hydrogen groups capable of reacting with. The weight average molecular weight per equivalent of the active hydrogen group is preferably in the range of 1,000 to 15,000, more preferably in the range of 2,000 to 10,000. If the weight average molecular weight per equivalent of the active hydrogen group is within such a range,
Appropriate wettability to the skin layer and the fiber base material is obtained, and sufficient initial adhesive strength and adhesive durability are obtained.

Examples of the active hydrogen group include a phenolic hydroxyl group, a hydroxyl group, an amino group, a mercapto group, and the like. A hydroxyl group, an amino group or a combination thereof is preferable, and a hydroxyl group is particularly preferable. As a method for introducing such a hydroxyl group or an amino group, any method can be used as long as it is a conventionally known method. For example, an excessive amount of a polyol and / or a glycol and a polyisocyanate are reacted with a molecular terminal. A method of introducing a hydroxyl group, a urethane prepolymer having an isocyanate group terminal to 2-aminoethanol, 2-aminoethylethanolamine, aminoalcohols such as diethanolamine,
Examples thereof include a method of introducing a hydroxyl group by reacting with aminophenol or the like. Examples of the method of introducing an amino group include a method of reacting an isocyanate-terminated urethane prepolymer with an excess amount of the amine compound with respect to the isocyanate group.

As the cross-linking agent (B) constituting the water-based dry laminate adhesive composition for synthetic leather of the present invention, the above polyisocyanate alone or at least a bifunctional or more of these isocyanurate type, allophanate type or burette type is used. Or a substantially hydrophobic polyisocyanate such as a urethane prepolymer having a terminal isocyanate group obtained by a reaction with an active hydrogen-containing compound such as a polyisocyanate compound or a polyol having two or more functional groups; Compounded so that it can be dispersed in water; self-emulsifying hydrophilic polyisocyanates obtained by copolymerizing a carboxyl group-containing compound, a sulfonic acid group-containing compound, or a nonionic group-containing compound with the above polyisocyanates As well as mixtures of these And the like.

The polyisocyanate compound used in the present invention may be either a skin layer, an aqueous system or an organic solvent system, but preferably the skin layer formed of a water-based urethane resin and the initial adhesion and adhesion durability to the fiber substrate. For application, it is usually used in combination with the water-based urethane resin.

Such a polyisocyanate compound is used after the curing by the curing reaction between the water-based urethane resin (A) and the crosslinking agent (B) in order to develop the adhesive durability such as the moist heat resistance of the finally obtained synthetic leather. Outflow start temperature is 12
It is preferable that the compounding amount be 0 ° C or higher, and more preferably 140 ° C or higher. The mixing ratio of the aqueous urethane resin (A) and the cross-linking agent (B) for achieving the outflow starting temperature is preferably 1 to 30 parts by weight (solid content) per 100 parts by weight of the urethane resin solid content, and It is preferably 2 to 20 parts by weight (solid content).

Furthermore, the aqueous dry laminate adhesive composition for synthetic leather of the present invention is preferably adjusted in viscosity according to various coating methods when it is applied to the surface layer formed on the release paper, It is preferable to use a thickener (C) as the viscosity adjusting method. Thickener (C) used in the present invention
As the thickener, a known and commonly used compound can be used as long as it is a thickener compatible with an aqueous urethane resin. For example, cellulose derivatives such as HEC (hydroxyethyl cellulose), MC (methyl cellulose), CMC (carboxymethyl cellulose), poly Examples thereof include acrylic acid salts, PVP (polyvinylpyrrolidone), and urethane-based and polyether-based associative thickeners.

Among these thickeners (C), the associative type which exhibits compatibility with an aqueous urethane resin and a relatively constant viscosity in a wide range under high to low shear forces, that is, Newtonian fluidity The use of a thickening agent is more excellent than the cellulose derivative having thixotropy and the like in terms of handling properties such as leveling property and film thickness adjustment when applying the resin composition to the substrate. preferable. These thickeners (C) may be used alone or in combination of two or more kinds.

Further, the water-based dry laminate adhesive composition for synthetic leather according to the present invention plays a role of adhesion to the outermost surface skin layer and the impregnated layer or the base material, so that the finally completed synthetic leather is Various color tones are adjusted depending on the use, design, design, etc. Therefore, also in the adhesive composition of the present invention, it is essential to unify the color tone with the skin layer, the impregnated layer or the base material for the part where the adhesive layer of the synthetic leather cross section appears as an appearance, and it must be possible to color with an aqueous pigment or the like. I have to. As the water-based pigment (D) used in the present invention, known and commonly-used water-based pigments can be used, and the dispersibility of the water-based pigment, storage stability, polyester fiber, nylon fiber and the like used as a base fabric of synthetic leather can be used. In consideration of physical properties such as adhesiveness, dry laminate physical properties, and hot pigments such as hot water resistance, an aqueous urethane resin obtained by using a dimer diol and / or a dimer acid type polyester polyol as a binder is used. The aqueous pigment used is particularly preferable in that it satisfies all the above physical properties. The aqueous urethane resin obtained by using the dimer diol and / or the dimer acid type polyester polyol in the present invention is, for example, so-called dimer diol or (b) dimer diol obtained by reducing (a) polymerized fatty acid, respectively. A so-called polyester polyol obtained by using a so-called polyester polyol or (c) a so-called polyester polyol obtained by using a so-called hydrogenated dimer acid obtained by hydrogenating a polymerized fatty acid, and (d) each of the above A diol or polyol belonging to (a) or (b) or a polyol other than the above-mentioned polyol belonging to (c),
(E) the above-mentioned organic isocyanate compound, (f) a compound having a hydrophilic group and having two functional groups reactive with an isocyanate group at both ends, and further, if necessary. , (G) a chain extender and / or (h) a terminal terminator, which are obtained by reacting them with each other.

In the adhesive composition of the present invention, in addition to water, other water-based dispersions and water dispersions such as vinyl acetate-based, ethylene vinyl acetate-based, and acrylic-based are added to the extent that the effects of the present invention are not impaired. , Acrylic styrene type emulsion; styrene
Butadiene-based, acrylonitrile-butadiene-based, acrylic-butadiene-based latex; polyethylene-based,
Ionomer of polyolefin type; various aqueous dispersions of polyester, polyurethane, polyethylene, polyamide, epoxy resin and the like, aqueous dispersions and the like may be used together.

Further, the adhesive composition of the present invention includes a urethane-forming catalyst such as dibutyltin laurate; an antioxidant such as hindered phenol-based, hindered amine-based, and natural-based antioxidants;
Various stabilizers such as hindered amine-based light resistance stabilizers, benzophenone-based, benzotriazole-based, cyanoacrylate-based UV absorbers, etc .; Fluorine-based, acetylene glycol-based hydrocarbon-based or silicone-based leveling agents; minerals Oil-based, silicone-based defoaming agents,
Additives such as a plasticizer, a tackifying resin, and a pot life extender may be blended and used.

The synthetic leather manufacturing method of the present invention comprises applying the above-mentioned aqueous dry laminate adhesive composition for synthetic leather of the present invention onto a skin layer previously formed on a release paper and drying the adhesive. A layer is formed, and then the adhesive layer and the fiber base material are dry-laminated. The skin layer used in the present invention is an organic solvent solution of urethane resin,
Alternatively, it is formed by using any one of water-based urethane resin as a main component, and the composition of the urethane resin is not particularly limited. The thickness of such a skin layer is generally preferably in the range of 5 to 100 μm after drying. The release paper used in the present invention is not particularly limited as long as it can be used without problems such as repellency, and a commercially available release paper for exclusive use of organic solvents or water can be used.

The method for applying the adhesive composition of the present invention onto the above-mentioned skin layer may be any conventionally known method and is not particularly limited, and for example, a gravure roll, a reverse roll, a rod, a knife over roll or the like may be used. Examples include coating methods. The coating thickness is preferably 5 to 100 μ after drying.
It may be in the range of m.

The method of drying the adhesive composition according to the present invention is as follows.
Any conventionally known drying method can be widely used. For example, a hot air drier, an infrared irradiation type drier, a microwave irradiation type drier, or a drying device in which at least two or more of them are used in combination can be used. The drying condition is not particularly limited as long as it is a drying condition necessary for the water in the aqueous dry laminate adhesive composition to be sufficiently evaporated, and is generally preferably in the range of 40 to 180 ° C., more preferably 60. Is in the range of 120 ° C. Overdrying not only causes thermal deterioration and deterioration of the skin layer, the fiber base material, or the adhesive layer, but also accelerates the curing reaction between the water-based urethane resin and the polyisocyanate compound, which may cause poor adhesion. Drying at a low temperature for a short time is preferable.

Since the adhesive layer thus obtained has a sufficient initial adhesiveness, it is successively superposed with a fiber base material and pressed by a pressure roll to a pressure of preferably 0.01 to 3 MPa, more preferably 0.05 to 1 MPa. By dry-laminating with, a synthetic leather having a soft texture without penetration or extrusion of the adhesive layer into the fiber base material can be obtained. Then, if necessary, by further aging it in an atmosphere of 20 to 60 ° C., it has stronger adhesiveness, and has hydrolysis resistance, wet heat resistance, cold resistance, heat resistance, water resistant adhesion, and washing resistance. A synthetic leather having excellent durability such as dry cleaning resistance can be obtained.

The fibrous base material used in the present invention can be widely used as long as it is a fibrous base material generally used in the production of synthetic leather. For example, synthetic fibers such as polyamide, polyester, polyacryl and the like. Improved fibers; natural fibers such as wool, silk, cotton and hemp; semi-synthetic fibers such as acetate and rayon; and fiber sheet materials such as woven and knitted fabrics and non-woven fabrics made of a mixture of these fibers. Further, those having a porous layer formed by coating (including foaming coating) or impregnating an organic solvent-based or water-based resin, preferably a urethane resin, on these fibrous sheet-like materials are also mentioned, and particularly preferred in the present invention. . Further, a natural leather material such as split leather can be used.

Further, the synthetic leather obtained by the method of the present invention is subjected to a surface treatment such as a top coat or a rubbing treatment in the final finishing step and put into practical use.

The synthetic leather of the present invention is characterized by being obtained by using the above-mentioned aqueous dry laminate adhesive composition for synthetic leather.

[0041]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following, all parts and% are based on weight unless otherwise specified. The various characteristics were measured by the evaluation methods outlined below. The average molecular weight of the polyol is the hydroxyl value (mgKOH /
It is a value calculated by the following equation from g). The unit is omitted below. Average molecular weight of polyol = (56100 / hydroxyl value) ×
(Number of hydroxyl groups per molecule of polyol)

[Synthesis Example 1] Preparation of Aqueous Urethane Resin 1 1000 parts of polypropylene glycol having a hydroxyl value of 56.1 and an average molecular weight of 2000, 47.2 parts of neopentyl glycol, 9.3 parts of trimethylolpropane, hydroxyl value = After the reaction of 68.6 parts of polyethylene glycol having an average molecular weight of 1000 and having an average molecular weight of 1000 of which one end is methoxy blocked with 247 parts of tolylene diisocyanate in 588 parts of methyl ethyl ketone (MEK) to synthesize an isocyanate-terminated prepolymer, a homomixer is used. While stirring, 2450 parts of water was added to emulsify the mixture, and 12.3 parts of 80% hydrated hydrazine and 20.6 parts of diethanolamine were dissolved in 296 parts of water to extend the chain, and finally the solvent was added. It was distilled off under reduced pressure to obtain an aqueous urethane resin 1 having a solid content of 50%. In addition, using Shimadzu Corporation advanced flow tester CFT-500D type, load 30k
When the outflow starting temperature and the melt viscosity of the resin obtained by using an orifice having a gf, an inner diameter of 1 mm and a length of 1 mm and a temperature rising rate of 3 ° C./min were measured, the outflow starting temperature was 4
It was 0 ° C. or less, and the melt viscosity at 80 ° C. was eluted and could not be measured.

[Synthesis Example 2] Preparation of Aqueous Urethane Resin 2 1000 parts of polypropylene glycol having a hydroxyl value of 56.1 and an average molecular weight of 2000 and 58.1 parts of neopentyl glycol, and an average molecular weight of 1000 having a hydroxyl value of 112.2. After 69.3 parts of polyethylene glycol and 255 parts of tolylene diisocyanate are reacted in 593 parts of MEK to synthesize an isocyanate-terminated prepolymer, 2469 parts of water is added with stirring with a homomixer to emulsify, and further 80% An aqueous solution prepared by dissolving 12.7 parts of hydrazine hydrate and 21.3 parts of diethanolamine in 306 parts of water was added to extend the chain, and finally the solvent was distilled off under reduced pressure to obtain an aqueous urethane resin 2 having a solid content of 50%. It was In addition, Shimadzu Corporation advanced flow tester CFT-500
Using a D type, using an orifice having a load of 30 kgf, an inner diameter of 1 mm and a length of 1 mm, and measuring the outflow start temperature and melt viscosity of the resin obtained under the conditions of a temperature rising rate of 3 ° C./min, the outflow start was found. The temperature was 40 ° C. or lower, and the melt viscosity at 80 ° C. was eluted and could not be measured.

Synthesis Example 3 Preparation of Aqueous Urethane Resin 3 1000 parts of polytetramethylene glycol having a hydroxyl value of 56.1 and an average molecular weight of 2,000, neopentyl glycol 45.9 parts, dimethylolpropionic acid 4
5.1 parts, average molecular weight 2,0 with hydroxyl value = 28.1
00. 75.7 parts of polyoxyethylene / polyoxypropylene glycol at one end and 345.8 parts of isophorone diisocyanate were reacted in 648 parts of MEK to synthesize an isocyanate-terminated prepolymer, and then 34 parts of triethylamine was added to the homopolymer. While stirring with a mixer, 1587 parts of water was added to emulsify, 44 parts of isophoronediamine was further dissolved in 197 parts of water to add an aqueous solution, and chain elongation was performed. Finally, the solvent was distilled off under reduced pressure to obtain a solid content of 40%. Aqueous urethane resin 3 was obtained. Further, a resin obtained by using Shimadzu Corporation high-performance flow tester CFT-500D type, with a load of 30 kgf, an inner diameter of 1 mm and an orifice of 1 mm, and a heating rate of 3 ° C./min. When the outflow starting temperature and the melt viscosity were measured, the outflow starting temperature was 110 ° C, and it was confirmed that the melt viscosity could not be measured at 80 ° C because it did not melt.

[Synthesis Example 4] Preparation of associative thickener a 600 parts of polyethylene glycol having a hydroxyl value of 14.0 and an average molecular weight of 8,000 and 133 parts of a 12 mol ethylene oxide adduct of distyrenated methylphenol were charged. After dehydration at 105 ° C. under reduced pressure, 37 parts of isophorone diisocyanate was added and reacted for 4 hours at 80 to 90 ° C., which was dissolved in water to obtain an associative thickener a having a solid content of 20%.

[Synthesis Example 5] Preparation of associative thickener b 500 parts of polyethylene glycol having a hydroxyl value of 18.7 and an average molecular weight of 6,000 and 234 parts of a 17 mol adduct of nonylphenol with ethylene oxide were charged under reduced pressure. After dehydration at 105 ° C., 35 parts of hexamethylene diisocyanate was added and reacted at 80 to 90 ° C. for 4 hours to be dissolved in water to obtain an associative thickener b having a solid content of 20%.

[Synthesis Example 6] Preparation of Binder for Aqueous Pigment "Pespol PP-200" [Toagosei]
Product name of hydrogenated dimer acid / ethylene glycol polyester polyol manufactured by Co., Ltd .; hydroxyl value = 82] 13
6.8 parts and 44.5 parts of isophorone diisocyanate were charged. It was then heated to 110 ° C. with stirring. After 1 hour, the mixture was cooled to 80 ° C., and 13.4 parts of dimethylolpropionic acid and 0.1% of tin octylate were added.
2 parts and 200 parts of MEK were added, and it was made to react at 80 degreeC for 7.5 hours. The NCO group content at this time was 0.07% in terms of solid content. This is cooled to 30 ° C. or lower, 7.5 parts of 25% ammonia water is added thereto, and then 600 parts of ion-exchanged water is added thereto to make O / W.
A type of emulsion was obtained. Then, distillation was performed under reduced pressure to remove the solvent and a part of water, and ion-exchanged water was added to adjust the concentration, whereby a transparent aqueous polyurethane was obtained.

[Synthesis Example 7] Preparation of Binder for Aqueous Pigment [0048] 294 parts of terephthalic acid, 294 parts of isophthalic acid, 131 parts of ethylene glycol and 223 parts of diethylene glycol were mixed, and the mixture was kept at 180 to 230 ° C for 8 hours. After heating for an esterification reaction at 230 ° C until the acid value becomes less than 1 mgKOH / g.
The condensation reaction was carried out for 6 hours. Then, dehydration treatment was carried out at 120 ° C. under reduced pressure, and after cooling to 90 ° C., 263 parts of MEK was added and well stirred to sufficiently dissolve them. A polyester polyol having a hydroxyl number of 50 and a hydroxyl value of 50 was obtained.
Then, with 226 parts of this polyester polyol,
After sufficiently stirring 44 parts of isophorone diisocyanate at 75 ° C., 2,2 as a chain extender
-Add 13 parts of dimethylolpropionic acid and add 70 ° C.
Then, it reacted for 12 hours. 4 after the reaction
After cooling to 0 ° C., the solution was solubilized by adding 35 parts of 5% aqueous ammonia. Then
After the methyl ethyl ketone was removed from the transparent reaction product thus obtained under reduced pressure at 60 ° C., ion-exchanged water was added to adjust the concentration,
A transparent aqueous polyurethane was obtained.

[Synthesis Example 8] Preparation of Aqueous Pigments 1 to 4 The binders for aqueous pigments obtained in Synthesis Examples 6 and 7 were blended in the proportions shown in Table 1, and kneaded for 30 minutes with a paint conditioner. Aqueous pigment compositions 1 to 4
Got

[0050]

[Table 1]

[Example 1] Water-based urethane resin Hydran WLS-210 (manufactured by Dainippon Ink and Chemicals, Inc.) /
Pigment / additive / thickener (urethane type) = 100/15 /
A release paper (DN-TP-APW DE-7 Dai Nippon Printing / Ajinomoto Co., Ltd.) was prepared by using a 0.3 / 1 (weight ratio) compounding solution for the skin.
Applied with a coating thickness of 80 μm (wet), and immediately pre-dried with Warner Matisse at 70 ° C. for 1 minute, then 120
It was dried at 0 ° C for 2 minutes. Further, aqueous urethane resin 1 (Synthesis example 1) / crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / associative thickener a (synthesis example 4) / aqueous pigment 1 = 100/10 /
A 2/5 (weight ratio) compounding liquid for adhesion was coated on the skin layer at a coating thickness of 80 μm (wet). After the application, it was dried with Warner Mathis at 70 ° C. for 1 minute, and immediately after the drying, the substrates were laminated (dry laminated). Then 12
Curing was performed at 0 ° C. for 2 minutes, and then aging was performed at 40 ° C. for 2 days, and the obtained work cloth was peeled from the release paper.

[Example 2] A water-based urethane resin 2 (Synthesis example 2) / crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / association type additive Sticking agent a (Synthesis example 4) / water-based pigment 1 = 10
Example 1 except that it was blended at 0/10/2/5 (weight ratio)
Processing was performed in the same manner as.

[Example 3] Solvent-based urethane resin Crisbon 7367SL (manufactured by Dainippon Ink and Chemicals, Inc.) /
Pigment / MEK / DMF = 100/15/30/10 (weight ratio) was used as a release paper (DN-TP-A).
PT flat was applied on Dai Nippon Printing Co., Ltd. (Ajinomoto Co., Inc.) with a coating thickness of 80 μm (wet), immediately pre-dried with Warner Mathis at 70 ° C. for 1 minute, and then at 120 ° C. for 2 minutes. Subsequent formulation and processing of the adhesive layer were performed in the same manner as in Example 1.

[Example 4] An aqueous urethane resin 1 (Synthesis example 1) / crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / association type additive Sticking agent a (Synthesis example 4) / water-based pigment 2 = 10
Example 1 except that it was blended at 0/10/2/5 (weight ratio)
Processing was performed in the same manner as.

[Example 5] An aqueous urethane resin 2 (Synthesis example 2) / crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / association type additive Adhesive b (Synthesis example 5) / water-based pigment 1 = 10
Example 1 except that it was blended at 0/10/2/5 (weight ratio)
Processing was performed in the same manner as.

[Example 6] An aqueous urethane resin 1 (Synthesis example 1) / crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / association type additive Adhesive (urethane type) / water-based pigment 2 = 10
Example 1 except that it was blended at 0/10/2/5 (weight ratio)
Processing was performed in the same manner as.

[Example 7] An aqueous urethane resin 1 (Synthesis example 1) / crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / carboxymethyl cellulose (Example 7) was prepared. CMC) / water-based pigment 1 = 100/10/2/5 (weight ratio) was used, and processing was performed in the same manner as in Example 1.

[Example 8] An aqueous urethane resin 1 (Synthesis example 1) / crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / association type additive Adhesive b (Synthesis example 5) / water-based pigment 3 = 10
Example 1 except that it was blended at 0/10/2/5 (weight ratio)
Processing was performed in the same manner as.

[Example 9] Aqueous urethane resin 1 (Synthesis example 1) / Crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / association type addition solution Adhesive b (Synthesis example 5) / water-based pigment 4 = 10
Example 1 except that it was blended at 0/10/2/5 (weight ratio)
Processing was performed in the same manner as.

Comparative Example 1 The skin layer was processed in the same manner as in Example 1. Further, aqueous urethane resin 3 (Synthesis example 3) / crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / associative thickener a
(Synthesis example 4) / Aqueous pigment 1 = 100/10/2/5 (weight ratio), and the adhesive compounding solution was applied on the skin layer to a thickness of 80.
It was applied in μm (wet). Immediately after coating, the substrates were laminated (wet laminating). After pasting,
Dry with Warner Matisse at 120 ° C for 2 minutes, then 40
The work cloth was peeled off from the release paper by aging at 0 ° C. for 2 days.

Comparative Example 2 The skin layer was processed in the same manner as in Example 1. Further, aqueous urethane resin 3 (Synthesis example 3) / crosslinking agent (water-dispersible polyisocyanate, solid content 100% by weight, NCO content 16-18% by weight) / associative thickener a
(Synthesis example 4) / Aqueous pigment 1 = 100/10/2/5 (weight ratio), and the adhesive compounding solution was applied on the skin layer to a thickness of 80.
It was applied in μm (wet). After coating, the same processing as in Example 1 was performed.

Comparative Example 3 Solvent-based urethane resin Crisbon 7367SL (manufactured by Dainippon Ink and Chemicals, Inc.) /
Pigment / MEK / DMF = 100/15/30/10 (weight ratio) was used as a release paper (DN-TP-A).
PT flat was applied on Dai Nippon Printing Co., Ltd., manufactured by Ajinomoto Co., Inc. with a coating thickness of 80 μm (wet). Immediately, it was pre-dried with Warner Mathis at 70 ° C. for 1 minute and then at 120 ° C. for 2 minutes. After that, solvent-based urethane resin Crisbon 4
070 (manufactured by Dainippon Ink and Chemicals, Inc.) / Crosslinking agent Crisbon NX (manufactured by Dainippon Ink and Chemicals, Inc.) / Catalyst Crisbon Axel HM (Dainippon Ink and Chemicals, Inc.)
Manufactured) / toluene / DMF = 100/12/3/20/1
The adhesive compounding solution, which was compounded in an amount of 0 (weight ratio), was applied on the skin layer at a coating thickness of 80 μm (wet). After coating, the same processing as in Example 1 was performed.

The processed cloths obtained in each of the above Examples and Comparative Examples were evaluated with respect to four items: the condition of the skin, the peel strength, the texture of the processed cloth, and the measures against volatile organic compounds (hereinafter referred to as VOC). . The evaluation results are shown in Table 2. (1) Evaluation method of the state of the skin The state of the unevenness of the skin was visually observed by an electron micrograph of the cross section of the processed cloth, and judged according to the following criteria. ○: No unevenness ×: Unevenness (2) Peel strength evaluation method Using Shimadzu Autograph AGS-G type (manufactured by Shimadzu Corporation), full scale 5 kg, head speed 2
The peel strength was measured under the condition of 0 mm / min. (3) Evaluation method of texture of the processed cloth The processed cloth was evaluated by touch according to the following criteria. ◯: Soft Δ: Touch feeling intermediate between soft and hard ×: Hard (4) VOC countermeasure Examples and Comparative Examples Evaluation was made by the content of the organic solvent in all the formulations. ○: 0 to 10% △: 10 to 50% ×: 50% or more

[0064]

[Table 2]

[0065]

[Table 3]

The annotations of Table 2 are as follows. * 1) D: dry laminate, W: wet laminate. * 2) kg / cm * 3) CMC: carboxymethyl cellulose

[0067]

EFFECTS OF THE INVENTION The adhesive composition for water-based dry laminate for synthetic leather obtained by the present invention and the method for producing synthetic leather using the same have no organic solvent or almost no organic solvent, and after the incorporation of the crosslinking agent. It has an excellent feature that the adhesive composition has little decrease in viscosity with time, and that it is possible to manufacture synthetic leather using an aqueous urethane resin having improved combined stability with an additive to be used together.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideyuki Takeuchi             3-17-14 Jobancho, Sakai City, Osaka Prefecture F-term (reference) 4F055 AA01 BA12 FA16 FA37 FA39                       GA03 GA11 GA32                 4J034 CA04 CA05 CA15 CC03 CC23                       CC26 CC45 CC52 CC61 CC65                       DA01 DB05 DC02 DC03 DC07                       DC12 DC34 DC35 DC43 DC50                       DD05 DF01 DF02 DF16 DF21                       DF22 DG03 DG04 DG05 DG06                       DG14 DG22 DG28 GA08 HA01                       HA07 HB11 HC03 HC12 HC13                       HC17 HC22 HC46 HC52 HC61                       HC64 HC67 HC71 HC73 JA44                       QB13 QB15 QC05 RA03                 4J040 EF051 EF111 EF121 EF131                       EF181 EF282 EF291 EF301                       GA05 HA126 KA16 KA25                       KA35 LA08 MA13 MB02

Claims (8)

[Claims] 1. In an adhesive composition comprising an aqueous urethane resin (A), a cross-linking agent (B), a thickener (C), and an aqueous pigment (D), the aqueous urethane resin (A) is intramolecular. As a hydrophilic group bound to, contains no anion type, cation type, and amphoteric type groups and contains only a nonionic hydrophilic group as an essential component, and (A) contains a nonionic hydrophilic group bound to the molecule. Compound is urethane resin solid content 100
1 to 30 parts by weight per part by weight, the outflow start temperature of the urethane resin solid content is 80 ° C. or less, and the outflow start temperature after the urethane resin reacts with the crosslinking agent (B) and is cured is 120. A water-based dry laminate adhesive composition for synthetic leather, characterized by having a temperature of at least ℃. 2. The water-based dry synthetic leather according to claim 1, wherein the water-based urethane resin (A) contains at least two active hydrogen groups capable of reacting with an isocyanate group, and the crosslinking agent (B) is a polyisocyanate compound. Laminating adhesive composition. 3. The water-based dry laminate adhesive composition for synthetic leather according to claim 1, further comprising a thickener (C). 4. The aqueous dry laminate adhesive composition for synthetic leather according to claim 3, wherein the thickener (C) is an associative thickener. 5. The method according to claim 1, further comprising an aqueous pigment (D), wherein the aqueous pigment (D) contains an aqueous urethane resin obtained by using a dimer diol and / or a dimer acid type polyester polyol as a binder. An aqueous dry laminate adhesive composition for synthetic leather according to any one of claims. 6. A water-based dry laminate adhesive composition for synthetic leather according to claim 1, which is applied onto a pre-formed skin layer on release paper and dried to form an adhesive layer. After the formation, a synthetic leather is produced by dry laminating the adhesive layer and the fiber base material. 7. Synthetic leather obtained by the manufacturing method according to claim 6. 8. Synthetic leather obtained by using the water-based dry laminate adhesive composition for synthetic leather according to any one of claims 1 to 5.