JP4149882B2 - Synthetic artificial leather and method for producing the same - Google Patents

Description

  The present invention relates to an ecological synthetic artificial leather using a hydrophilic polyurethane resin that can be dispersed or emulsified in an environmentally-friendly aqueous medium that is effective for measures against volatile organic compounds (VOC). ), Hydrolysis resistance, light resistance, heat resistance, gas discoloration resistance, weather resistance, oleic acid resistance, cold resistance, solvent resistance, chemical resistance, stain resistance, lubricity, migration The present invention relates to a synthetic artificial leather (artificial leather, synthetic leather) excellent in properties, water repellency, oil repellency, mechanical strength, abrasion resistance, flexibility, and the like, and a method for producing the same. The synthetic artificial leather of the present invention is suitable for manufacturing all synthetic artificial leather products such as shoes, bags, clothing, furniture such as chairs and sofas, and vehicle seats.

  Polyurethane resin has excellent physical properties such as wear resistance, adhesion, flexibility, chemical resistance, and suitability for various processing methods, so synthetic artificial leather (generic name for artificial leather and synthetic leather) It is widely used as a binder for materials, various coating agents, inks, paints, etc., or as a material for films, sheets and various molded products, and polyurethane resins suitable for various applications have been proposed. Here, the polyurethane resin is a general term for polyurethane resin, polyurea resin, and polyurethane-polyurea resin. These polyurethane-based resins are basically obtained by reacting a high-molecular-weight polyol component, an organic polyisocyanate component, and further a chain extender component as necessary. A polyurethane-based resin having performance is provided.

  Conventionally, synthetic artificial leather using a polyurethane-based resin has been conventionally produced by, for example, a wet method through the following main steps. First, for example, a solution of an organic solvent mainly composed of N, N-dimethylformamide (DMF), which is a polyurethane resin, is applied on a fibrous base material layer and solidified in water to form a microporous layer. Next, a polyurethane resin solution dissolved in various organic solvents is directly coated on the microporous layer with a coating machine such as a gravure and dried to form a skin layer (silver surface layer), or a polyurethane resin. The solution is applied onto a release paper, dried, and a film formed is subjected to transfer surface formation using an adhesive to form a skin layer (see Non-Patent Document 1, Patent Documents 1 and 2).

  Thus, when manufacturing the synthetic artificial leather skin, most of the raw polyurethane resin is used as a solution dissolved in various organic solvents. Therefore, in the drying process, the organic solvent is released into the atmosphere. From the viewpoint of environmental problems (VOC countermeasures), safety and health, and fire fighting countermeasures, there is an increasing need for polyurethane resin aqueous dispersions that do not use organic solvents. ing. In the conventional polyurethane resin aqueous dispersion, the film formed using it does not fully satisfy the required performance of synthetic artificial leather such as adhesion to the base material, flexibility, water resistance, etc. Is required.

Edited by Keiji Iwata, Polyurethane resin handbook, pages 571-599, 15. Polyurethane leather (published by Nikkan Kogyo Shimbun, September 25, 1987) JP-A-5-5280 JP-A-9-31861

  However, polyurethane-based resins used for synthetic artificial leather (artificial leather, synthetic leather) and various coating agents are usually solvent-based polyurethane resins that are usually used as organic solvent solutions. The current situation is that work environment is not supported. In addition, the physical properties required for polyurethane resins in the above applications include hydrolysis resistance, light resistance, heat resistance, gas discoloration resistance, weather resistance, oleic acid resistance (human sweat component), etc. as durability. In particular, the physical properties required for synthetic artificial leather include natural leather-like appearance, soft texture, high strength, wear resistance, low-temperature flexibility, surface touch, blocking resistance, adhesion to substrates, etc. Are required at the same time.

  The present invention has been made in view of various problems in the conventional synthetic artificial leather using the solvent-based polyurethane resin as described above. The present invention provides an environment-friendly polyurethane resin aqueous dispersion. It is an object of the present invention to provide a synthetic artificial leather having a skin layer satisfying required physical properties and a method for producing the same.

  The above object is achieved by the present invention described below. That is, in the present invention, the skin layer has polyisocyanate, (A) a compound having at least one hydrophilic group other than a hydroxyl group and at least one active hydrogen-containing group, and (B) a side chain having 8 carbon atoms. A long chain alkyl group-containing compound having ~ 64 alkyl groups and at least one active hydrogen-containing group; and (C) a polysiloxane compound having at least one active hydrogen-containing group in the absence of a chain extender. Or a synthetic artificial leather comprising a layer containing a hydrophilic polyurethane resin having a long side chain obtained by reaction in the presence of the synthetic artificial leather and a method for producing the same.

  According to the present invention, hydrolysis resistance, light resistance, heat resistance, texture, adhesion strength to a substrate, water repellency, low temperature flexibility, wear resistance using an aqueous dispersion of polyurethane resin as an ecological material. A highly durable synthetic artificial leather with excellent properties is provided.

Next, the present invention will be described in more detail.
Synthetic artificial leather has various structures such as those in which a skin layer is provided on a nonwoven fabric impregnated with polyurethane resin, and a microporous layer of polyurethane resin is formed on a base fabric and a surface layer is provided thereon. In the present invention, the structure of the synthetic artificial leather may be any structure, and the skin layer is characterized by being formed from a layer containing a long-chain side chain-containing hydrophilic polyurethane resin. .
The long-chain side chain-containing hydrophilic polyurethane resin used in the present invention is a hydrophilic polyurethane resin capable of forming an aqueous dispersion, and in the polyurethane molecular chain, a unit having a hydrophilic group other than a hydroxyl group and a side chain It is a hydrophilic polyurethane resin having a unit having a long-chain alkyl group and a polysiloxane segment (unit), and these units are connected by a urethane bond and / or a urea bond. Further, in addition to each of the above units, it is a hydrophilic polyurethane resin having a unit having a low molecular weight polymer chain in the side chain or main chain and a unit from polyol and / or polyamine. The hydrophilic group in the resin is partially or completely neutralized.
In the present invention, the long-chain side chain-containing hydrophilic polyurethane resin includes polyurethane having a urethane bond and / or urea bond, polyurea, and polyurethane-polyurea.

  These long-chain side chain-containing hydrophilic polyurethane resins are composed of polyisocyanate, preferably diisocyanate, (A) at least one hydrophilic group other than hydroxyl group, preferably one and at least one active hydrogen-containing group, preferably And (B) a linear or branched alkyl group having 8 to 64 carbon atoms as a side chain (hereinafter sometimes referred to as a long-chain alkyl group. Unsaturated in the alkyl group) And a compound having a long-chain alkyl group having at least one active hydrogen-containing group and (C) at least one active hydrogen-containing group, preferably 2 Long-chain side-chain-containing hydrophilic polyurethane resin obtained by reacting a polysiloxane compound having one with a chain extender (short-chain diol, short-chain diamine, etc.) if necessary, and the above components In addition, (D) a long-chain side chain containing (E) a low molecular weight polymer having at least one active hydrogen-containing group at one end, preferably two, and (E) a polyol and / or a polyamine are reacted. It is a hydrophilic polyurethane resin. The active hydrogen-containing group in the present invention refers to a functional group having active hydrogen such as a hydroxyl group, a mercapto group, a carboxyl group, and an amino group reactive with an isocyanate group.

  The long-chain side-chain-containing hydrophilic polyurethane resin used in the present invention is a known synthesis method using a reaction catalyst as required under the absence of a solvent or using an organic solvent (recovered after production of an aqueous dispersion). After the reaction, the obtained long-chain side chain-containing hydrophilic polyurethane resin is used in water or a mixed solvent of water and a hydrophilic solvent (hereinafter referred to as an aqueous medium) using a neutralizing agent. It can be dispersed or emulsified to form a polyurethane aqueous dispersion. This is because the neutralizing agent partially or completely neutralizes the hydrophilic group in the long-chain side chain-containing hydrophilic polyurethane resin so that the resin can be dispersed in an aqueous medium or self-emulsified. As a result, a very stable self-dispersing or self-emulsifying polyurethane-based resin aqueous dispersion is produced, and a synthetic artificial leather characterized by being environmentally friendly is provided using this.

(Function)
The hydrophilic polyurethane resin used in the present invention containing a hydrophilic functional group, a long-chain alkyl group, a polysiloxane segment, and a low molecular weight polymer chain, a polyol chain and / or a polyamine chain is a urethane bond and / or a urea bond. The long chain alkyl group and the low molecular weight polymer chain form a branch portion, and the polysiloxane segment has a single-end reaction on the trunk portion if the raw material component is, for example, a double-end reactive type. If it is a type, it is introduced into the branch part. When a dry coating film is formed on the surface of a pseudo leather substrate such as a cloth or nonwoven fabric from the aqueous dispersion of the long-chain side-chain-containing hydrophilic polyurethane resin, from the difference in surface energy between the above units or segments. The polysiloxane segment having a low surface energy, the long chain alkyl group of the branch part and the low molecular weight polymer chain part are on the surface layer, the part having a urethane bond and / or urea bond and the hydrophilic functional group part are on the substrate side Oriented to

  Therefore, the synthetic artificial leather has a smooth surface touch and natural leather material because the long chain alkyl group part of the side chain, the low molecular weight polymer chain of the branch part and the polysiloxane segment are oriented to the surface layer side of the base material. It becomes the same surface touch. In addition, the polysiloxane segment and the long-chain alkyl group part exhibit a water repellency function, a contamination prevention function, and the like, thereby further enhancing the function. Furthermore, the polysiloxane segment, given its structure, imparts good durability such as heat resistance, light resistance, and hydrolysis resistance to the polyurethane resin, and when this polyurethane resin is processed into synthetic artificial leather, Effects such as soft texture), abrasion resistance, cold resistance, and blocking resistance are exhibited. On the other hand, the part having a trunk urethane bond and / or urea bond and the hydrophilic functional group part improve the strength and flexibility of the polyurethane resin film, and improve the adhesion between the film and the substrate.

The raw material components used for the production of the long-chain side chain-containing hydrophilic polyurethane resin of the present invention will be described below.
(A) Compounds having both a hydrophilic group other than one hydroxyl group and preferably at least one, preferably two active hydrogen-containing groups in the same molecule include sulfonic acid and carboxylic acid , Phosphoric acid and amine compounds can be used. This component has the effect of imparting adhesiveness to the base fabric to the hydrophilic polyurethane resin by the hydrophilic group and the function of stably dispersing and self-emulsifying the resin in the aqueous medium.
For example, examples of the sulfonic acid compound include the following compounds and derivatives thereof.

Examples of the carboxylic acid compounds include dimethylolpropanoic acid, dimethylolbutanoic acid and their alkylene oxide low-mole adducts (number average molecular weight less than 500) and γ-caprolactone low-mole adducts (number average molecular weight less than 500). ), Half esters derived from an acid anhydride and glycerin, and compounds derived from a monomer containing a hydroxyl group and an unsaturated group and a monomer containing a carboxyl group and an unsaturated group by a free radical reaction.
The above are examples of preferred compounds used in the present invention, and the present invention is not limited to these exemplified compounds.
Accordingly, not only the exemplified compounds described above, but also any other compounds that are currently commercially available and can be easily obtained from the market can be used in the present invention.

(B) A side chain for introducing a unit having a long-chain alkyl group as a side chain into a polyurethane resin molecular chain has an alkyl group having 8 to 64 carbon atoms and at least one, preferably two active hydrogen-containing groups. As a compound, a C8-64 linear or branched alkyl group (which may contain an unsaturated group) and adjacent carbon atoms or 1 to 3 carbon atoms are present in the molecule. A typical example is a bifunctional organic compound having an active hydrogen-containing group at each of two carbon atoms. Examples of such compounds include 1,2- or 1,3-alkanediols (HOCH ₂ CH (OH) R, HOCH ₂ CH ₂ CH (OH) R) and dehydrated dimers thereof (HOCH (R ) CH ₂ OCH ₂ (R) CHOH etc.) (wherein R is the above alkyl group); 1,2- or 1,3-alkanediamines; 1- or 2-monoglycerides and monoglycerin ethers, etc. It is mentioned as preferable. Particularly preferred is 1,2-alkanediol.

  Examples of 1,2- or 1,3-alkanediols include octane 1,2 (or 1,3) -diol, decane 1,2 (or 1,3) -diol, dodecane 1,2 (or 1). , 3) -diol, tetradecane 1,2 (or 1,3) -diol, octadecane 1,2 (or 1,3) -diol, tetracosane 1,2 (or 1,3) -diol, and the like. Examples of the 1- or 2-monoglyceride include, for example, 1- (or 2-) monocaprin glyceride, 1- (or 2-) monolauring glyceride, 1- (or 2-) monomyristating glyceride, 1- (or 2-). Examples of monopalmiting glyceride, 1- (or 2-) monoaraking glyceride, and 1- or 2-monoglycerol ether include batyl alcohol, seraalkyl alcohol, and chimyl alcohol.

In addition to the above, hydroxy fatty acids, 1,2- or 1,3-alkanediamines, symmetric α-glycols (RCH (OH) CH (OH) R) (R is the above alkyl group), and alkylenes thereof Oxide low molar adduct (number average molecular weight less than 500), higher alcohols and polyester diols of the above 1,2- or 1,3-alkanediol and dibasic acid (OHCH (R) CH ₂ OC (O) R 'CO (O) CH ₂ CH (R) OH, etc.) (wherein R is the above alkyl group, R' is a divalent organic group that is a residue of a dibasic acid), and the like.
These are examples of preferred compounds used in the present invention. The present invention is not limited to these exemplified compounds, and any other compounds that are readily available from the currently marketed market are Can be used for invention.

(D) The low molecular weight polymer having at least one active hydrogen-containing group at one molecular terminal used in the present invention has at least one, preferably two active hydrogen-containing groups at one molecular chain terminal. Any low molecular weight polymer can be used, and the type of polymer is not particularly limited. Preferred are those having a glass transition temperature of 80 ° C. or lower, and more preferred are those having a glass transition temperature of −100 to 20 ° C. Any of these low molecular weight polymers can be used regardless of the kind of monomers constituting them. The weight average molecular weight in terms of standard polystyrene by the GPC method is usually about 1,000 to 20,000.

The production method of such a low molecular weight polymer is not particularly limited. For example, a (meth) acrylic polymer produced by radical polymerization uses a thioglycol represented by the following formula as a chain transfer agent ( Two active hydrogens are contained at the molecular terminals by polymerizing a meth) acrylic monomer or the like by a known method (for example, a bulk polymerization method using a bulk polymerization catalyst described in JP-A No. 2000-128911). A low molecular weight polymer having a group (with a polymer chain bonded to an S atom of the following formula) can be obtained.

(C) As the polysiloxane compound having at least one, preferably two, active hydrogen-containing groups used in the present invention, for example, the following compounds can be used.
(1) Amino-modified polysiloxane compound

(2) Epoxy-modified polysiloxane compound

(3) Alcohol-modified polysiloxane compound

(4) Mercapto-modified polysiloxane compound

  The polysiloxane compounds having active hydrogen-containing groups listed above are preferred compounds used in the present invention, and the present invention is not limited to these exemplified compounds. Accordingly, not only the above-exemplified compounds but also any other compounds that are currently commercially available and can be easily obtained from the market can be used in the present invention. Particularly preferred compounds in the present invention are polysiloxane compounds having two hydroxyl groups or amino groups.

(E) As the polyol used in the present invention, conventionally known polyols such as short-chain diols and polymer polyols conventionally used in the production of polyurethane, and as polyamines are conventionally used in the production of polyurethane. Although the short chain diamine etc. currently used can be used, these are not specifically limited.

Examples of the short-chain diol include aliphatic glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexamethylene glycol, neopentyl glycol, and the like. Alkylene oxide low molar adduct (number average molecular weight less than 500); 1,4-bishydroxymethylcyclohexane, alicyclic glycols such as 2-methyl-1,1-cyclohexanedimethanol, and alkylene oxide low molar adducts thereof (Number average molecular weight less than 500); Aromatic glycols such as xylylene glycol and their alkylene oxide low molar adducts (number average molecular weight less than 500); Bisphenols such as bisphenol A, thiobisphenol, sulfone bisphenol and their alkylenes Kishido low molar adduct (number average molecular weight of less than 500); Compound alkyl dialkanolamines such as alkyl diethanolamine C ₁ -C ₁₈ and the like. Examples of the polyhydric alcohol compound include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, tris- (2-hydroxyethyl) isocyanurate, 1,1,1-trimethylolethane, 1,1, Examples include 1-trimethylolpropane. These can be used alone or in combination of two or more.

Examples of the polymer polyol include the following.
(1) Polyether polyols such as those obtained by polymerizing or copolymerizing alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) and / or heterocyclic ethers (tetrahydrofuran, etc.), specifically polyethylene glycol , Polypropylene glycol, polyethylene glycol-polytetramethylene glycol (block or random), polytetramethylene ether glycol, polyhexamethylene glycol, etc.

(2) Polyester polyol, for example, aliphatic dicarboxylic acids (for example, succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, etc.) and / or aromatic dicarboxylic acids (for example, isophthalic acid, terephthalic acid, etc.) And low molecular weight glycols (for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexamethylene glycol, neopentyl glycol, 1,4-bishydroxy Methyl polycyclohexane etc.), specifically polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentyl adipate diol, polyethylene / butylene adipate diol, polyneope Chill / hexyl adipate diol, poly-3-methylpentane adipate diol, polybutylene isophthalate diol,

(3) Polylactone polyol, such as polycaprolactone diol or triol, poly-3-methylvalerolactone diol,
(4) Polycarbonate diol, such as polyhexamethylene carbonate,
(5) Polyolefin polyol, such as polybutadiene glycol, polyisoprene glycol or hydride thereof,
(6) Polymethacrylate diols, for example, α, ω-polymethyl methacrylate diol, α, ω-polybutyl methacrylate diol, and the like.
The molecular weight of these polyols is not particularly limited, but the number average molecular weight is usually about 500 to 2,000. Moreover, these polyols can be used individually or in combination of 2 or more types.

  Examples of polyamines include short chain diamines, aliphatic, aromatic diamines and hydrazines. Examples of the short-chain diamine include aliphatic diamine compounds such as methylene diamine, ethylene diamine, trimethylene diamine, hexamethylene diamine, and octamethylene diamine; phenylene diamine, 3,3′-dichloro-4,4′-diaminodiphenyl methane, 4, Aromatic diamine compounds such as 4'-methylenebis (phenylamine), 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone; cyclopentadiamine, cyclohexyldiamine, 4,4-diaminodicyclohexylmethane, 1,4 -Alicyclic diamine compounds, such as diaminocyclohexane and isophorone diamine, etc. are mentioned. Further, hydrazines such as hydrazine, carbodihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide and the like can be mentioned. These can be used alone or in combination of two or more. As a polyol and a polyamine, a diol compound and a diamine compound are preferable.

  As the polyisocyanate compound used in the present invention, any of those conventionally used for producing polyurethane can be used and is not particularly limited. For example, preferred are toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy- 1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 4,4'-methylenebis (phenylene isocyanate) (MDI), jurylene diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), 1,5-naphthalene diisocyanate, benzidine Aromatic diisocyanates such as diisocyanate, o-nitrobenzidine diisocyanate, 4,4'-diisocyanate dibenzyl;

  Aliphatic diisocyanates such as methylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,10-decamethylene diisocyanate; 1,4-cyclohexylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate), Obtained by reacting 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, alicyclic diisocyanates such as hydrogenated MDI, hydrogenated XDI, etc., or these diisocyanate compounds with low molecular weight polyols and polyamines so that the terminal is isocyanate. Naturally, polyurethane prepolymers and the like can also be used.

When producing the polyurethane aqueous dispersion used in the present invention, first, 1 to 30% by weight of the above-mentioned compound, (A) a compound having both a hydrophilic group other than a hydroxyl group and an active hydrogen-containing group, B) 1 to 95% by weight of a compound having a long-chain alkyl group and an active hydrogen-containing group in the side chain, (C) 1 to 90% by weight of a polysiloxane compound having an active hydrogen-containing group, (D) one molecule A low molecular weight polymer having an active hydrogen-containing group at the terminal is used in a proportion of 0 to 80% by weight, and (E) polyol and / or polyamine is used in a proportion of 0 to 80% by weight (however, the sum of A to E is 100% by weight). Thus, a long-chain side-chain-containing hydrophilic polyurethane resin is synthesized. If necessary, an appropriate amount of a chain extender (the desired amount of chain extender) is added so that the equivalent ratio of all active hydrogen-containing groups to isocyanate groups in these reaction components is approximately 1.0. A hydrophilic polyurethane resin is synthesized by reacting in the presence of the molecular weight and the desired physical properties until there is no isocyanate group. The reaction may be a one-shot method or a multistage method, and is usually carried out at 20 to 150 ° C, preferably 60 to 110 ° C. Thereafter, the obtained polyurethane resin is dispersed or emulsified in an aqueous medium using a neutralizing agent to obtain a self-dispersing or emulsifying stable polyurethane aqueous dispersion. In addition, (D) and (E) in the above reaction components are components that are not necessary, and are used to adjust the solution viscosity, adhesive strength, film strength, and film hardness of the resulting hydrophilic polyurethane resin. .
As for the molecular weight of these obtained long-chain side chain-containing hydrophilic polyurethane resins, the weight average molecular weight (measured by GPC, standard polystyrene conversion) is preferably in the range of 2,000 to 500,000.

  In the present invention, a catalyst can be used as needed during urethane synthesis. Examples of the catalyst include dibutyltin laurate, dioctyltin laurate, stannous octoate, lead octylate, salts of organic and inorganic acids such as tetra-n-butyl titanate, and organic metal derivatives such as triethylamine. Examples include amines and diazabicycloundecene catalysts.

In the present invention, the polyurethane synthesis reaction may be performed without a solvent or in an organic solvent. In the case of using an organic solvent, after the polyurethane aqueous dispersion is produced, the organic solvent is removed by an appropriate means such as vacuum distillation.
Preferable examples of the organic solvent include those that are inert to isocyanate groups or that are less active than the reaction components. Examples of such solvents include ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), aromatic hydrocarbon solvents (toluene, xylene, swazol (aromatic hydrocarbon solvent manufactured by Cosmo Oil Co., Ltd.). ), Solvesso (aromatic hydrocarbon solvent manufactured by Exxon Chemical Co., Ltd.), aliphatic hydrocarbon solvents (n-hexane, etc.), alcohol solvents (methanol, ethanol, isopropanol, etc.), ether solvents (dioxane, Tetrahydrofuran, etc.), ester solvents (ethyl acetate, butyl acetate, isobutyl acetate, etc.), glycol ether ester solvents (ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, Til-3-ethoxypropionate), amide solvents (dimethylformamide, dimethylacetamide, etc.), lactam solvents (n-methyl-2-pyrrolidone, etc.) Among these, solvent recovery, urethane synthesis Considering the solubility, reactivity, boiling point, and emulsifying dispersibility in water, methyl ethyl ketone, ethyl acetate, acetone, tetrahydrofuran and the like are particularly preferable.

  In the present invention, when an isocyanate group remains at the polymer terminal during urethane synthesis, a reaction terminator at the isocyanate terminal may be added. As the reaction terminator, for example, not only monofunctional compounds such as monoalcohols and monoamines, but also compounds having two functional groups having different reactivities with respect to isocyanate can be used. For example, monoalcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol; monoethylamine, n-propylamine, diethylamine, di-n-propylamine, Examples include monoamines such as di-n-butylamine; alkanolamines such as monoethanolamine and diethanolamine. Among them, alkanolamines are preferable in that the reaction can be easily controlled.

  As a neutralizing agent used when producing an aqueous dispersion of a long-chain side chain-containing polyurethane resin, for example, for anionic components (sulfonic acid type, carboxylic acid type, etc.), organic amines (ammonia, ethylamine) are used. , Trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N-methylmorpholine, 2-amino-2 -Ethyl-1-propanol etc.), alkali metals (lithium, potassium, sodium etc.), inorganic alkalis (lithium hydroxide, sodium hydroxide, potassium hydroxide etc.). On the other hand, for the cationic component (tertiary amine type), for example, formic acid, lactic acid, acetic acid and the like can be mentioned, and these can be used alone or in combination of two or more.

The long-chain side-chain-containing hydrophilic polyurethane resin that forms the polyurethane aqueous dispersion used in the present invention has a compound (A) when (1) the above-mentioned compounds (A) to (C) are used as structural units. 1) to 30% by weight, preferably 2 to 20% by weight of units introduced from 1) to 95% by weight, preferably 5 to 70% by weight of units introduced from compound (B). Long-chain side chain-containing hydrophilicity containing 1 to 90% by weight of units to be introduced, preferably 1 to 80% by weight (the total of units introduced from compounds (A) to (C) is 100% by weight) A polyurethane resin is preferred.
In addition, when (2) the above-mentioned compounds (A) to (E) are used as the structural unit, the unit introduced from the compound (A) is 1 to 30% by weight, preferably 2 to 20% by weight, 1 to 95% by weight of units introduced from the compound (B), preferably 5 to 70% by weight, 1 to 90% by weight of units introduced from the compound (C), preferably 1 to 80% by weight, 1) to 80% by weight of units introduced from D), preferably 1 to 60% by weight and 1 to 80% by weight of units introduced from compound (E), preferably 1 to 60% by weight (compound (A) The total of units introduced from (E) is 100% by weight.) The long-chain side-chain-containing hydrophilic polyurethane resin contained is preferable.

  The unit introduced from each of the above-mentioned compounds (A) to (E) constituting the long-chain side-chain-containing hydrophilic polyurethane resin used in the present invention is such that each of these compounds has two active hydrogen-containing groups, for example, For example, in the case where the polyisocyanate is a diisocyanate (OCN-R-NCO) having hydroxyl groups at both ends of the molecular chain, the OH group of each compound (HO-X-OH) reacts with the isocyanate group of the diisocyanate. The compound forms a urethane bond as described below and is incorporated into the main chain of the polyurethane molecular chain. If a high molecular weight diamine is used as the compound (E), a unit to be introduced from this unit is linked to another unit by a urea bond. Further, when a chain extender is used, when a low molecular diol or diamine is used as the chain extender, a structure in which molecular chains including units connected by the above bonds are connected by urethane bonds or urea bonds is obtained. Therefore, in the present invention, the hydrophilic polyurethane resin includes a polyurethane resin having a urethane bond in a molecular chain and a polyurethane-polyurea resin having a urethane bond and a urea bond. Further, when a compound having an amino group as an active hydrogen-containing group is used, when a short chain diamine is further used as a chain extender, a polyurea resin in which each unit is connected by a urea bond is produced. Therefore, in the present invention, the hydrophilic polyurethane resin includes a polyurea resin.

  In the synthetic artificial leather of the present invention, a skin layer composed of a layer containing the above-mentioned long-chain side chain-containing hydrophilic polyurethane resin is formed on a base fabric constituting a core part. The base fabric constituting the core can be any base fabric used in the manufacture of conventionally known synthetic artificial leather, and it is only necessary to select an optimal base fabric for the purpose of using the synthetic artificial leather, and is particularly limited. It is not a thing. Examples thereof include woven fabrics and nonwoven fabrics impregnated with a polyurethane resin, and a fibrous base material in which a microporous layer of a polyurethane resin is formed.

  For the formation of the skin layer, a polyurethane aqueous dispersion in which the long-chain side chain-containing hydrophilic polyurethane resin is dispersed or emulsified in an aqueous medium using a neutralizing agent is used. A known method can be used, and the production method itself is not particularly limited. The paint using the above-mentioned polyurethane aqueous dispersion used for forming the skin layer can be used only with the aqueous dispersion, but if necessary, it is conventionally used for the production of synthetic artificial leather using a polyurethane resin. Various additives can be added and used. Various additives include, for example, antioxidants (hindered phenols, phosphites, thioethers, etc.), light stabilizers (hindered amines, etc.), ultraviolet absorbers (benzophenones, benzotriazoles, etc.), gas discoloration, etc. Stabilizers (hydrazine, etc.), hydrolysis inhibitors (carbodiimide, etc.), metal deactivators, colorants such as pigments, thickeners, crosslinking agents, crosslinking accelerators, matting agents such as silica, other binder resins, etc. And additives suitable for the purpose of use of the synthetic artificial leather are used. In that case, the coating material using the polyurethane water-based dispersion is used by adjusting a predetermined viscosity and solid content by adding a necessary amount of a desired additive.

In the case of producing a synthetic artificial leather having a crosslinked skin layer in the present invention, a polyurethane aqueous dispersion to which a crosslinking agent or the like is added is used as a paint. The cross-linking method may be any cross-linking method using the reactivity of hydrophilic groups such as urethane groups and / or carboxyl groups in the long-chain side chain-containing hydrophilic polyurethane resin, and a cross-linking agent suitable for these methods is selected. Is done.
Examples of the crosslinking agent used in the crosslinking method using a urethane group include a polyisocyanate crosslinking agent. As the polyisocyanate crosslinking agent, any known ones conventionally used in such a crosslinking method can be used and are not particularly limited. For example, dimer of 2,4-toluylene diisocyanate, triphenylmethane triisocyanate, tris- (p-isocyanatephenyl) thiophosphite, polyfunctional aromatic isocyanate, polyfunctional aromatic aliphatic isocyanate, polyfunctional aliphatic Examples thereof include blocked polyisocyanates such as isocyanate, fatty acid-modified polyfunctional aliphatic isocyanate, and blocked polyfunctional aliphatic isocyanate, and polyisocyanate prepolymers. These polyisocyanate cross-linking agents are particularly effective in improving various physical properties (hydrolysis resistance, heat resistance, light resistance, adhesion imparting, etc.) if they are in appropriate amounts. In order to remain and cause adverse effects such as deterioration of various physical properties, it is preferable to use 120 parts by weight or less, preferably 1 to 50 parts by weight with respect to 100 parts by weight of the polyurethane resin.

  As a crosslinking agent used in a crosslinking method utilizing a hydrophilic group, for example, a carboxyl group, for example, an epoxy-based crosslinking agent, a carbodiimide-based crosslinking agent, an oxazoline-based crosslinking agent or a metal complex-based crosslinking agent has been conventionally used. Any known one can be used and is not particularly limited. For example, as the epoxy-based crosslinking agent, a conventionally known commercially available epoxy resin such as “Epicoat” (manufactured by Yuka Shell Epoxy Co., Ltd.) can be added and used. As the carbodiimide-based crosslinking agent, a commercial product of “Carbodilite” trade name (manufactured by Nisshinbo Industries, Inc.) can be obtained and used. Moreover, as an oxazoline type crosslinking agent, the commercial item of the brand name (made by Nippon Shokubai Co., Ltd.) of "Epocross" can be obtained and used. As the metal complex-based crosslinking agent, titanium organic compound-based, zirconium organic compound-based commercially available under the trade name of “Orgatyx” (manufactured by Matsumoto Pharmaceutical Co., Ltd.) are available, and aluminum, chromium, cobalt, copper, Iron, nickel, vanadium, zinc, indium, calcium, magnesium, manganese, yttrium, cerium, strontium, palladium, barium, molybdenium, lanthanum, tin sold under the trade name "Narsem" (manufactured by Nippon Kagaku Sangyo Co., Ltd.) An acetylacetone complex can be obtained and used. These crosslinking agents are particularly effective for improving various physical properties if they are in appropriate amounts, but if the amount used is too large, it will cause a significant shortening of the usable life and embrittlement of the film. On the other hand, it is preferable to use 40 parts by weight or less, preferably 0.5 to 20 parts by weight.

  A binder resin other than the long-chain side chain-containing hydrophilic polyurethane resin can be added to the paint using the polyurethane aqueous dispersion used in the production of the synthetic artificial leather in the present invention. As the binder resin, any binder resin conventionally used in the production of synthetic artificial leather using a polyurethane resin can be used, and is not particularly limited. For example, conventionally known silicone resins, polyester resins, polyamide resins, polyimide resins, polystyrene resins, polyurethane resins, polycarbonate resins, norbornene resins, cellulose resins, polyvinyl alcohol resins, polyvinyl formal resins , Polyvinyl butyral resins, polyvinyl pyrrolidone resins, polyvinyl acetate resins, polyvinyl acetal resins, and the like. Although the usage-amount of these resin is not specifically limited, Usually, it is 900 weight part or less with respect to 100 weight part of this polyurethane resin, Preferably it is the range of 5-400 weight part.

  In the skin layer-forming coating material, if necessary, designability imparting agents (organic fine particles, inorganic fine particles), antistatic agents, antifungal agents, flame retardants and other additives can be used as appropriate. Examples of the organic fine particles and inorganic fine particles include silicone resin fine particles, fluororesin fine particles, acrylic resin fine particles, urethane resin fine particles, polyethylene resin fine particles, and reactive siloxane. Examples of the antistatic agent include metal oxides such as carbon black, tin oxide, and titanium oxide, various metal alkoxides, conductive fillers such as ITO powder, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and modified ethylene oxide. And the like.

  In addition, when forming a synthetic artificial leather in the present invention, when a crosslinking agent is not used, the coating is used as one liquid. When a crosslinking agent is used, an aqueous dispersion of the crosslinking agent and a crosslinking agent are used. It is used as two liquids with paint that does not contain. Although the solid content of a coating material is not specifically limited, Usually, it is about 1 to 95 weight%. Solvent-free solid long-chain side chain-containing hydrophilic polyurethane resin can also be used for forming the skin layer. Needless to say, a solution of a long-chain side-chain-containing hydrophilic polyurethane resin can be used as usual. In that case, measures against VOC are necessary.

  When forming the skin layer of the synthetic artificial leather of the present invention, the skin layer-forming coating material containing the polyurethane aqueous dispersion of the present invention prepared as described above is applied to the base fabric or the top thereof by a conventionally known method. It is applied to the microporous layer of the provided polyurethane resin and dried. The coating method is not particularly limited. For example, a surface forming method in which a coating material for forming a skin layer is directly applied onto a base fabric using a gravure coater, comma coater, knife coater, air knife coater, etc., and a skin layer is formed using a release paper. For example, a method of forming a film from a coating material and thermally transferring it onto a base fabric using a hot melt or a two-component water-based polyurethane adhesive may be used. Although the dry thickness of a skin layer is not specifically limited, Usually, it is about 5-30 micrometers. Moreover, in order to improve the surface designability of the finished synthetic artificial leather, a surface treatment agent can be applied or embossed.

  Hereinafter, the present invention will be described more specifically with reference to production examples, examples and comparative examples, but the present invention is not limited thereto. In the following text, “parts” represents parts by weight, and “%” represents weight percent.

[Production Examples 1 to 4 and Comparative Production Examples 1 to 3]
After replacing the reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen blowing tube, and a manhole with nitrogen gas, (A) a hydrophilic group-containing compound component of the type and amount shown in Tables 1 and 2, ( B) a long-chain alkyl group-containing diol component (referred to as “long-chain alkyl group-containing compound”), (C) a polysiloxane component having a hydroxyl group at both ends or one end, and a chain extender (short-chain diol component), Alternatively, (D) a low molecular weight polymer component having a hydroxyl group at one end and (E) a high molecular diol component (referred to as “polyol component”) are further added to these components, and a predetermined amount of tetrahydrofuran is added and uniformly dissolved. The solution concentration was adjusted. Subsequently, a predetermined amount of hexamethylene diisocyanate (HDI) was added and reacted at 80 ° C. After confirming that there was no absorption due to free isocyanate groups of 2,270 cm ^{−1 in} the infrared absorption spectrum, the mixture was cooled to 50 ° C. and predetermined solid content (Production Examples 1-4: 45%; Comparative Production Example 1:30) %) Ion exchange water and a predetermined amount of neutralizing agent were added to uniformly emulsify the system. Finally, the tetrahydrofuran in the system was recovered by vacuum degassing to obtain a polyurethane aqueous dispersion. Tables 1 and 2 show the raw material composition of polyurethane, the properties of the paint (aqueous dispersion) and polyurethane (PU). In Comparative Production Examples 2 and 3, the reaction solution (solid content 30%) remains as it is, and neutralization and emulsification are not performed.
In addition, the molecular weight of polyurethane is a weight average molecular weight in terms of standard polystyrene measured by GPC. For the polysiloxane content, the siloxane content measured by the infrared spectroscopic analysis method of JIS K0117 was displayed as the polysiloxane content.

(note)
(A)
A-1: dimethylolbutanoic acid A-2: dimethylolpropanoic acid (B)
B-1: AOG-X68 (1,2-hydroxyalkane (manufactured by Daicel Chemical Industries))
_{CH 2 (OH) -CH (OH} ) - (CH 2) n CH 3
(N is an integer, average molecular weight 360)
B-2: AOG-Y08 (1,2-hydroxyalkane (manufactured by Daicel Chemical Industries))
_{CH 2 (OH) -CH (OH} ) - (CH 2) n CH 3
(N is an integer, average molecular weight 550)

・Ｃ−２：（Ｘ−２２−１７６ＤＸ、片末端ポリシロキサンジオール（信越化学社製）

(C)
C-1: (KF-6001, both-end polysiloxane diol (manufactured by Shin-Etsu Chemical)

C-2: (X-22-176DX, one terminal polysiloxane diol (manufactured by Shin-Etsu Chemical Co., Ltd.)

（Ｒ₁＝Ｈ又はＣＨ₃、Ｒ₂＝エチル基、平均分子量２，０００、Ｔｇ＝−２４℃）
（Ｅ）
・ＰＣＤ：プラクセルＣＤ２２０（ポリカーボネートジオール（ダイセル化学工業社製、ｎは整数、平均分子量２，０００）

ＴＥＡ：トリエチルアミン
架橋剤：カルボジライトＶ−０２（日清紡績社製、カルボジイミド系架橋剤） (D)
・ D-1:

(R ₁ = H or CH ₃ , R ₂ = ethyl group, average molecular weight 2,000, Tg = −24 ° C.)
(E)
PCD: Plaxel CD220 (polycarbonate diol (manufactured by Daicel Chemical Industries, n is an integer, average molecular weight 2,000)

TEA: Triethylamine crosslinking agent: Carbodilite V-02 (Nisshinbo Co., Ltd., carbodiimide crosslinking agent)

Examples 1-4, Comparative Examples 1-3
(1) Fabrication of base fabric A polyester nonwoven fabric was sufficiently impregnated with an impregnating liquid composition prepared by the following formulation, followed by drying and thermosetting at 120 ° C. to produce a nonwoven fabric with flexibility. .
(Impregnating liquid composition)
・ Rezamin CUT-270W 100 parts (Daiichi Seika Kogyo Co., Ltd. silicone emulsion)
・ 75 parts of Rezamin CUT-275C (catalyst dispersion manufactured by Dainichi Seika Kogyo Co., Ltd.)
・ 600 parts of ion exchange water

Subsequently, a wet composition liquid was prepared with the following formulation, impregnated into the nonwoven fabric obtained above, wet coagulated according to a conventional method, washed and dried. Subsequently, in order to impart surface smoothness to the nonwoven fabric, the surface portion on which the skin was formed was buffed to obtain an impregnated nonwoven fabric (synthetic artificial leather base fabric) having a very soft texture. The above wet coagulation was performed in a system in which DMF of the urethane resin solution and DMF in the coagulation tank were collected.
・ 100 parts of Rezamin CU-8445 (ether-type PU manufactured by Dainichi Seika Kogyo Co., Ltd.)
・ Rezamin CUT-30 2 parts (wet additive manufactured by Dainichi Seika Kogyo Co., Ltd.)
・ Rezamin CUT-107 3 parts (Daiichi Seika Kogyo Co., Ltd. wet additive)
・ Rezamin CUT-250 Kai 1 part (wet additive manufactured by Dainichi Seika Kogyo Co., Ltd.)
・ DMF 250 parts

(2) Production of synthetic artificial leather Using the above-mentioned base fabric, prepared on the surface thereof using the polyurethane aqueous dispersion or polyurethane organic solvent solution of Production Examples 1 to 4 and Comparative Production Examples 1 to 3 in the following formulation Each synthetic artificial leather composition was applied directly with a knife coater so that the thickness after drying was 15 μm, and water or an organic solvent was dried in a dryer to produce a synthetic artificial leather having a skin layer. did.
(I) (Aqueous polyurethane: Production Examples 1 to 4 (solid content 45%), Comparative Production Example 1 (solid content 30%))
・ Polyurethane aqueous dispersion 100 parts ・ Seika Seven DW-794 Black 25 parts ・ Ion exchange water Amount of solid content 20% (ii) (Polyurethane solution: Comparative production examples 2 and 3 (solid content 30%))
・ 100 parts of polyurethane solution ・ Seika Seven DW-780 (s) black
20 parts ・ MEK / DMF = 1/1 (weight ratio)
The amount that the solid content becomes 20%

  Each of the synthetic artificial leather sheets obtained as described above was tested for hydrolysis resistance, light resistance, heat resistance, texture, adhesive strength, water repellency, low temperature flexibility, wear resistance and the like. The evaluation results are shown in Table 3 below.

The display contents of each test method and test result are shown below.
[VOC countermeasures]
When the solvent used is 0, ◯, less than 5% are indicated by Δ, and 5% or more are indicated by ×.
[appearance]
The sensibility for viewing is good.
[Texture]
A volumey and soft one is marked with ◯, a middle with △, and a hardware with x.
[Low temperature flexibility]
In a flexo testing machine, 0 ° C., 20,000 times of bending, no change in performance is indicated by ○, some cracks are indicated by Δ, and severe cracks are indicated by ×.
[Abrasion resistance]
Using a Taber wear machine, the wear wheel H22, load 500g, 100 times when there is no visual change, ◯, when there is slight wear, △, when severe wear is indicated as x.

[Adhesiveness]
The surfaces of the synthetic artificial leather were pasted with an adhesive, and the adhesive strength (peel strength) was measured. Adhesive strength of 2 kg / cm or more was evaluated as ○, 1 kg / cm or more and less than 2 kg / cm as Δ, and less than 1 kg / cm as x.
[Water repellency]
When water drops were dropped on the surface layer of synthetic artificial leather tilted at 45 ° C. with a dropper, those that repel water were indicated as ◯, and those that did not repel were indicated as ×.
[Hydrolysis resistance]
The adhesion strength with the base fabric after the jungle test (temperature: 70 ° C., relative humidity 95%, 3 weeks) was measured and compared with the initial strength before the test. A retention rate of 70% or more was indicated as ◯, 40% or more and less than 70% as Δ, and less than 40% as ×.
[Light resistance]
The adhesive strength with the base fabric after the sunshine weatherometer test (temperature: 63 ° C., no water, 120 hours) was measured and compared with the initial strength before the test.
A retention rate of 70% or more was indicated as ◯, 40% or more and less than 70% as Δ, and less than 40% as ×.
[Heat-resistant]
The test was carried out in a gear oven, and the temperature was measured at 120 ° C. for 150 hours after the adhesive strength with the base fabric and compared with the initial strength.
A retention rate of 70% or more was indicated as ◯, 40% or more and less than 70% as Δ, and less than 40% as ×.

Claims (7)

The skin layer is a polyisocyanate, (A) a compound having at least one hydrophilic group other than a hydroxyl group and at least one active hydrogen-containing group, and (B) an alkyl group having 8 to 64 carbon atoms in the side chain. And a long-chain alkyl group-containing compound having at least one active hydrogen-containing group and (C) a polysiloxane compound having at least one active hydrogen-containing group in the absence or presence of a chain extender A synthetic artificial leather comprising a layer containing a hydrophilic polyurethane resin having a long-chain side chain obtained by the treatment. A hydrophilic polyurethane resin having a long side chain comprises the above component, (D) a low molecular weight polymer having at least one active hydrogen-containing group at one end of the molecular chain, (E) a polyol and / or a polyamine. The synthetic artificial leather according to claim 1, which is obtained by reacting. The synthetic artificial leather according to claim 1 or 2, wherein the compound (A) is a diol having a carboxyl group, a sulfonic acid group or an amino group. The synthetic artificial leather according to any one of claims 1 to 3, wherein the compound (B) is 1,2-alkanediol. The synthetic artificial leather according to claim 2, wherein the compound (D) is a low molecular weight polymer having two hydroxyl groups at one end. In producing a synthetic artificial leather having a skin layer, for the formation of the skin layer, (A) a compound having at least one hydrophilic group other than a hydroxyl group and at least one active hydrogen-containing group (B) A long chain alkyl group-containing compound having an alkyl group having 8 to 64 carbon atoms and at least one active hydrogen-containing group in the side chain; and (C) a polysiloxane compound having at least one active hydrogen-containing group. An aqueous dispersion obtained by dispersing or emulsifying a hydrophilic polyurethane resin having a long chain side chain obtained by reacting in the absence or presence of a chain extender in an aqueous medium using a neutralizing agent was used. A method for producing synthetic artificial leather, characterized by using a paint. A hydrophilic polyurethane resin having a long side chain comprises the above component, (D) a low molecular weight polymer having at least one active hydrogen-containing group at one end of the molecular chain, (E) a polyol and / or a polyamine. The method for producing a synthetic artificial leather according to claim 6 , wherein the synthetic artificial leather is obtained by reacting.