JP2007314919A - Surface finishing agent for leather and leather using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface finishing agent for leather, which is composed of an aqueous resin composition having excellent coating suitability and imparts high abrasion resistance to the leather without substantially containing an organic solvent and to provide the leather using the surface finishing agent. <P>SOLUTION: The surface finishing agent for the leather is composed of the aqueous resin composition. Furthermore, the aqueous resin composition comprises 100 pts.mass of an aqueous polyurethane resin (A), 40-100 pts.mass of a polyisocyanate-based cross-linking agent (B), 5-25 pts.mass of a silicone-based compound (C) and 5-120 pts.mass of a filler (D). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a leather surface finish comprising a water-based resin composition that is substantially free of an organic solvent, is excellent in coating suitability, and can improve the abrasion resistance of leather, and leather using the same.

  Conventional resin compositions used for artificial leather and synthetic leather are mainly solvent-based using an organic solvent in order to improve the film-forming property. However, when this solvent-type resin composition is used, the organic solvent is volatilized in the drying process, and most of it is released into the atmosphere, which deteriorates the environment. In addition, since the organic solvent is volatilized, the working environment is not good, and there is concern about the health of workers. Furthermore, when an organic solvent with a high boiling point such as N, N-dimethylformamide (DMF) is used, a part of it remains in artificial leather or synthetic leather even after drying, and there is concern that the residual solvent may affect the human body. Has been. As a method for solving this problem, development of artificial leather and synthetic leather using an aqueous resin composition substantially free of an organic solvent has been underway.

  In addition, in artificial leather using an aqueous resin composition, in addition to flexibility, high wear strength (Taber) is used for sports shoes, clothing, furniture, and the like, similar to artificial leather using a solvent-type resin composition. Abrasion) is required. However, the artificial leather using the aqueous resin composition has a problem that the artificial leather using the solvent-type resin composition is poor in flexibility and the Taber wear resistance is inferior. This is thought to be because artificial leather using an aqueous resin composition is prone to film formation failure and the resin film is fragile, so that cracks occur when the surface is bent or the resin film falls off when worn. .

  In order to solve the above problem, an aqueous coating composition containing at least one hydroxyl group-containing polyester dispersion, an aqueous urethane substantially free of hydroxyl groups or amino groups, and a polyisocyanate has been proposed. Even in the resin composition, the abrasion resistance was not sufficient (see, for example, Patent Document 1).

  Further, an aqueous surface finish for forming a fiber laminate surface layer, which is a polyurethane resin having an acid value of 5 to 40 and contains an aqueous polyurethane resin dispersion containing no emulsifier and a crosslinking agent, has been proposed. However, this resin composition also has insufficient wear resistance. (For example, refer to Patent Document 2).

  Furthermore, although a two-component aqueous polyurethane coating composition of an aqueous-dispersed hydroxyl group-containing polyurethane and a water-dispersible polyisocyanate has been proposed, the abrasion resistance is not sufficient. Moreover, in order to ensure leveling property or film-forming property, an organic solvent such as N-methylpyrrolidone is used, and there is a concern about the influence of this organic solvent on the human body, which causes environmental problems. For example, see Patent Document 3).

Therefore, there is a need for a leather surface finish comprising an aqueous resin composition that can improve the abrasion resistance of artificial leather and the like produced using the aqueous resin composition and that is substantially free of organic solvents. It was.
JP-A-9-157585 JP 2003-119679 A Japanese Patent Laid-Open No. 4-239883

  A problem to be solved by the present invention is a leather surface finish comprising an aqueous resin composition that is substantially free of organic solvents, has excellent coating suitability, and can impart high wear resistance to leather, and It is to provide the leather used.

  As a result of intensive studies to solve the above problems, the present inventors formulated a large excess of polyisocyanate-based crosslinking agent and silicone-based compound with respect to the aqueous polyurethane resin, and further formulated an organic or inorganic filler. Thus, it was found that a leather surface finish comprising an aqueous resin composition that is excellent in coating suitability and can impart high wear resistance to leather without substantially using an organic solvent. .

  That is, the present invention relates to 100 parts by mass of an aqueous polyurethane resin (A), 40 to 100 parts by mass of a polyisocyanate crosslinking agent (B), 5 to 25 parts by mass of a silicone compound (C), and 5 to 120 fillers (D). It is intended to provide a leather surface finish and a leather using the same, comprising an aqueous resin composition containing parts by mass.

  Since the surface finish for leather of the present invention does not substantially contain an organic solvent, it has excellent characteristics with a low environmental load. In addition, since it is possible to form a coating film with excellent film-forming properties that could not be obtained with conventional water-based resin compositions, it has excellent wear resistance, so it is environmentally friendly vehicle seats, sports shoes, clothing, furniture. It can be optimally used for leather used for such applications.

  The aqueous polyurethane resin (A) used in the present invention has active hydrogen that can be crosslinked with the polyisocyanate-based crosslinking agent (B) described later, and has a hydrophilic group that can be dissolved or dispersed in an aqueous medium. Any material can be used without particular limitation. Examples of such an aqueous polyurethane resin (A) include polycarbonate-based, polyether-based, and polyester-based ones. Also, polycarbonate is preferred for uses such as vehicle seats and furniture that require high wear resistance, and polyether is preferred for uses such as sports shoes where soft texture is important. Furthermore, what modified | denatured with the silicone compound can also be used as water-based polyurethane resin (A).

  The aqueous polyurethane resin (A) reacts with a compound (a-1) having active hydrogen, a compound (a-2) having at least one active hydrogen and a hydrophilic group, and a compound (a-3) having an isocyanate group. Is obtained. The active hydrogen capable of crosslinking with the polyisocyanate-based crosslinking agent (B) is obtained by leaving or introducing a functional group having active hydrogen after the reaction of these compounds, and is dissolved in an aqueous medium. Or the hydrophilic group which can be disperse | distributed is similarly obtained by leaving or introduce | transducing a hydrophilic group after reaction of these compounds.

  Examples of the functional group of the compound (a-1) having active hydrogen include a hydroxyl group, a phenolic hydroxyl group, an amino group, a mercapto group, and the like. Among these, a hydroxyl group, a carboxyl group, and an amino group are preferable. Further, the compound having active hydrogen is preferably one having two or more of these functional groups in one molecule.

  Examples of the active hydrogen-containing compound (a-1) include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5. -Pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1, 4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, hydroquinone and their alkylene oxide adducts, glycerin, trimethylolethane, trimethylolpropane, sol Torr, and a relatively low molecular weight polyols such as pentaerythritol.

  Moreover, as the compound (a-1) having active hydrogen other than the above, for example, polyester polyol, polyether polyol, polycarbonate polyol, polyacetal polyol, polyacrylate polyol, polyesteramide polyol, polythioether polyol, polyolefin polyol, polyamine, etc. Is mentioned. These compounds having active hydrogen can be used alone or in combination of two or more.

  The polyester polyol is obtained by copolymerizing a polyester obtained by a dehydration condensation reaction such as a diol compound, a dicarboxylic acid compound, or a hydroxycarboxylic acid compound, a ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone, and the like. can get. Examples of the diol compound used as a raw material for the polyester polyol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5-pentane. Diol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1 , 4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, hydroquinone, and alkylene oxide adducts thereof.

  Examples of the dicarboxylic acid compound used as a raw material for the polyester polyol include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, 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- And bis (phenoxy) ethane-p, p′-dicarboxylic acid.

  Furthermore, examples of the hydroxycarboxylic acid compound used as a raw material for the polyester polyol include p-hydroxybenzoic acid and p- (2-hydroxyethoxy) benzoic acid.

  Examples of the polyether polyol include 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, aconite sugar, femellitic acid, phosphoric acid, ethylenediamine, diethylenetriamine, triisopropanolamine, pyrogallol, dihydroxybenzoic acid, hydroxyphthalic acid, 1,2,3-propane Compounds with two or more active hydrogens such as trithiol, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin Tetrahydrofuran, obtained by addition polymerization of cyclic ether compounds such as cycloalkyl Fe xylene, or the cyclic ether compound cationic catalyst, protonic acids include those of Lewis acid to ring-opening polymerization as a catalyst.

  The polycarbonate polyol can be obtained by reacting a diol compound such as 1,4-butanediol, 1,6-hexanediol, diethylene glycol and the like with diphenyl carbonate and phosgene.

  Examples of the polyamine include ethylenediamine, 1,6-hexamethylenediamine, piperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 3,3′-dimethyl-4,4′-dicyclohexylmethanediamine. 1,4-cyclohexanediamine, 1,2-propanediamine, diethylenetriamine, triethylenetetramine, hydrazine and the like.

  As the compound (a-2) having at least one active hydrogen and a hydrophilic group, the compound having at least one active hydrogen and a hydrophilic group, for example, a carboxyl group, a sulfonic acid group and a salt thereof, Examples thereof include a compound having a nonionic hydrophilic group having a repeating unit of alkylene oxide. These compounds having at least one active hydrogen and a hydrophilic group can be used alone or in combination of two or more.

  Examples of the compound having a carboxyl group as a hydrophilic group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolvaleric acid, dioxymaleic acid, and 2,6-dioxybenzoic acid. 3,4-diaminobenzoic acid, succinic acid, adipic acid, maleic acid, phthalic acid, alanine, aminobutyric acid, aminocaproic acid, glycine, glutamic acid, aspartic acid, histidine and the like, and a hydroxyl group or amino group A compound or a dicarboxylic acid compound.

  Examples of the compound having a sulfonic acid group as a hydrophilic group include 2-oxyethanesulfonic acid, phenolsulfonic acid, sulfobenzoic acid, sulfosuccinic acid, 5-sulfoisophthalic acid, sulfanilic acid, and 1,3-phenylenediamine. Examples thereof include compounds having a sulfonic acid group such as -4,6-disulfonic acid and 2,4-diaminotoluene-5-sulfonic acid and a hydroxyl group, a carboxyl group or an amino group, or a disulfonic acid compound.

  Furthermore, examples of the compound having a nonionic hydrophilic group as the hydrophilic group include polyethylene glycol, polypropylene glycol, a copolymer of ethylene oxide and propylene oxide, a copolymer of ethylene oxide and polybutylene oxide, and ethylene oxide. Examples include copolymers with other alkylene oxides.

  Examples of the compound (a-3) having an isocyanate group include 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, Camethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4 , 4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate, and other polyisocyanates. These compounds having an isocyanate group can be used alone or in combination of two or more.

  Among these, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate are preferable because they can reduce raw material costs, and 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclophene. Xylmethane diisocyanate is preferable because it can improve light resistance and heat resistance.

  The aqueous polyurethane resin (A) is dissolved or dispersed in an aqueous medium as a functional group such as a hydroxyl group, a carboxyl group, and an amino group as active hydrogen capable of crosslinking with the polyisocyanate-based crosslinking agent (B) described later. Examples of methods for leaving or introducing functional groups such as a carboxyl group, a sulfonic acid group, and a nonionic hydrophilic group after the urethanization reaction of the aqueous polyurethane resin (A) as a hydrophilic group capable of forming the following include the following methods.

(Method to leave or introduce hydroxyl group)
For example, a method in which an excess amount of polyol and polyisocyanate are reacted to leave a hydroxyl group at the end, a urethane prepolymer having an isocyanate group at the end is prepared by reacting polyol and an excess amount of polyisocyanate, and this urethane prepolymer and 2 -A method of introducing a hydroxyl group by reacting amino alcohols such as aminoethanol, 2- (2-aminoethylamino) ethanol and diethanolamine, aminophenol and the like.

(Method of introducing carboxyl group)
For example, in order to obtain the said aqueous polyurethane resin (A), it has carboxyl groups, such as 2, 2- dimethylol propionic acid, 2, 2- dimethylol butyric acid, 2, 2- dimethylol valeric acid, when performing a urethanation reaction. Examples include a method of copolymerizing a compound and introducing a carboxyl group.

(Method of introducing amino group)
For example, after preparing a urethane prepolymer having an isocyanate group at the terminal by reacting a polyol with an excess amount of polyisocyanate, this urethane prepolymer and an excess amount of ethylenediamine, 1,6-hexamethylenediamine, piperazine, isophoronediamine, etc. A method of introducing an amino group by reacting with a polyamine is mentioned.

(Method of introducing sulfonic acid group)
For example, in order to obtain the aqueous polyurethane resin (A), a compound having a sulfonic acid group such as 2-oxyethanesulfonic acid, phenolsulfonic acid, sulfobenzoic acid, and sulfosuccinic acid is copolymerized during the urethanization reaction. And a method of introducing a sulfonic acid group.

(Method of introducing a nonionic hydrophilic group)
For example, in order to obtain the water-based polyurethane resin (A), a compound having a nonionic hydrophilic group such as polyethylene glycol, polypropylene glycol, or a copolymer of ethylene oxide and propylene oxide is copolymerized during the urethanization reaction. And a method of introducing a nonionic hydrophilic group.

  Further, the carboxyl group or sulfonic acid group in the aqueous polyurethane resin (A) can be neutralized to form a salt, and the obtained polyurethane resin can be dissolved or dispersed more satisfactorily in an aqueous medium. Examples of the neutralizing agent include non-volatile bases such as sodium hydroxide and potassium hydroxide; volatile bases such as ammonia; and organic amines such as trimethylamine, triethylamine, dimethylethanolamine, methyldiethanolamine, and triethanolamine. It is done. The neutralization operation can be performed before, during, or after the urethanization reaction.

  Furthermore, when manufacturing the said water-based polyurethane resin (A), you may use an emulsifier as needed. Examples of the emulsifier include nonionic emulsifiers such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrenated phenyl ether, and polyoxyethylene sorbitol tetraoleate; fatty acid salts such as sodium oleate, alkyl Anionic emulsifiers such as sulfate ester salts, alkylbenzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, alkane sulfonate sodium salts, sodium alkyl diphenyl ether sulfonates; polyoxyethylene alkyl sulfates, polyoxyethylene alkylphenyls Nonionic anionic emulsifiers such as sulfates; Cationic emulsifiers such as alkyltrimethylammonium salts; Fluorine and silicone special emulsifiers It is below.

  Examples of the method for producing the aqueous dispersion of the aqueous polyurethane resin (A) include the following methods.

  A nonionic emulsifier is added to an organic solvent solution or an organic solvent dispersion of a urethane resin having a carboxyl group obtained by reacting a compound having active hydrogen, a compound having a carboxyl group, and a polyisocyanate, and further, if necessary. A method of adding a neutralizer and then mixing with water to obtain an aqueous dispersion.

  An aqueous solution containing a compound having active hydrogen, a compound having a carboxyl group and a urethane prepolymer having an isocyanate group at the terminal obtained by reacting a polyisocyanate with a nonionic emulsifier and, if necessary, a neutralizing agent Or an aqueous solution containing a nonionic emulsifier is mixed and dispersed in water and then reacted with a polyamine to obtain an aqueous dispersion.

  A compound having an active hydrogen, a compound having a carboxyl group, a compound having a nonionic hydrophilic group, and an organic solvent solution or an organic solvent dispersion of a urethane resin having a hydrophilic group obtained by reacting a polyisocyanate, if necessary. A method of adding a neutralizer and further mixing water to obtain an aqueous dispersion.

  An aqueous solution containing a neutralizing agent in a compound having active hydrogen, a compound having a carboxyl group, a compound having a nonionic hydrophilic group, and a urethane prepolymer having an isocyanate group at the terminal and a hydrophilic group obtained by reacting with a polyisocyanate; A method of mixing, or previously adding a neutralizing agent to a prepolymer, mixing water and dispersing in water, adding a polyamine and reacting to obtain an aqueous dispersion.

  A compound having active hydrogen, a compound having a carboxyl group, a compound having a nonionic hydrophilic group, and a urethane prepolymer having an isocyanate group at the terminal obtained by reacting a polyisocyanate with a neutralizing agent and a polyamine A method in which an aqueous dispersion is obtained by mixing with an aqueous solution or adding a neutralizing agent in advance to the prepolymer and then mixing with an aqueous solution containing a polyamine.

  The aqueous dispersion of the aqueous polyurethane resin (A) can be produced in the absence of a solvent, but an organic solvent may be used for the purpose of controlling the reaction or reducing the viscosity. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; acetates such as ethyl acetate and butyl acetate; N, N-dimethylformamide And amides such as N-methyl-2-pyrrolidone. When these organic solvents are used, they are removed as much as possible from the aqueous dispersion of the finally obtained aqueous polyurethane resin (A). Moreover, it is preferable to use an organic solvent having a relatively low boiling point that can be easily removed. When it is unavoidable to use an organic solvent having a boiling point of 100 ° C. or higher, the amount used is preferably kept to a minimum.

  The polyisocyanate-based crosslinking agent (B) used in the present invention preferably does not contain an organic solvent, and more preferably has good dispersibility in the aqueous dispersion of the aqueous polyurethane resin (A). In addition, it is preferable to use a liquid at room temperature (25 ° C.) since the film forming property is improved.

  As said polyisocyanate type crosslinking agent (B), the compound (a-3) which has an isocyanate group used as a raw material of the said water-based polyurethane resin (A), these isocyanurate type, burette type, or alphanate type 3 Hydrophobic polyisocyanates such as urethane prepolymers having an isocyanate group at the terminal obtained by reaction of a compound such as a polyisocyanate having a functionality or higher, a polyol having two or more active hydrogens and a compound having an isocyanate group; The above-mentioned emulsifier is mixed with an isocyanate so that it can be dispersed in water; the compound having a carboxyl group, the compound having a sulfonic acid group, or the compound having a nonionic hydrophilic group and the polyisocyanate are used together. Self-emulsifying property obtained by polymerization Water-dispersible polyisocyanates; and mixtures thereof. Among these, a hydrophobic polyisocyanate which is composed of an aliphatic or alicyclic polyisocyanate and can be dispersed in an aqueous dispersion of the aqueous polyurethane resin (A) is preferable because water resistance is improved. In addition, the water-dispersible polyisocyanate obtained by reacting an aliphatic or alicyclic polyisocyanate with a compound having a nonionic hydrophilic group has high dispersibility in the aqueous dispersion of the aqueous polyurethane resin (A). preferable.

  Further, as the polyisocyanate crosslinking agent (B), one type of polyisocyanate can be used alone, or two or more types of polyisocyanate can be used in combination.

  In the leather surface finish of the present invention, high abrasion resistance can be imparted by blending the polyisocyanate-based crosslinking agent (B). Moreover, the range of 40-100 mass parts is preferable with respect to 100 mass parts of water-based polyurethane resin (A), The range of 40-100 mass parts is more preferable, The range of 50-80 mass parts is more preferable, 55-55 mass parts. The range of 60 parts by mass is more preferable. Thus, high film-forming property and abrasion resistance can be imparted to the aqueous polyurethane resin (A) by blending the polyisocyanate-based crosslinking agent (B) in excess of the usual blending amount. When the blending amount of the polyisocyanate-based crosslinking agent (B) is less than 30 parts by mass, sufficient film-forming properties and wear resistance cannot be obtained, and when it exceeds 100 parts by mass, the coating film becomes hard and textured. Is insufficient.

  The silicone-based compound (C) used in the present invention includes polydimethylsilicone, hydrogenated silicone, vinyl modified silicone, hydroxy modified silicone, amino modified silicone, carboxyl modified silicone, halogenated modified silicone, epoxy modified silicone, methacryloxy modified silicone, Mercapto-modified silicones, fluorine-modified silicones, alkyl-modified silicones, phenyl-modified silicones, polyether-modified silicones, etc. Among them, water dispersibility is good and handling is good, and there is little bleeding out from the coating film, and leveling It is preferable to use a polyether-modified silicone having excellent properties. Among these, those not containing an organic solvent are preferable, and those having good dispersibility in the aqueous polyurethane resin (A) are more preferable.

  In the surface finish for leather of the present invention, high abrasion resistance can be imparted by blending the silicone compound (C). Moreover, the range of 5-25 mass parts is preferable with respect to 100 mass parts of aqueous polyurethane resin (A), and the range of 8-15 mass parts is more preferable. Thus, high abrasion resistance can be imparted to the aqueous polyurethane resin (A) by blending the silicone compound (C) in excess of the usual blending amount. In addition, when the compounding amount of the silicone compound (C) is less than 5 parts by mass, sufficient wear resistance cannot be obtained, and when it exceeds 25 parts by mass, the silicone compound (C) bleeds out. .

  The filler (D) used in the present invention may be an organic filler or an inorganic filler. Examples of the inorganic filler include silica, calcium carbonate, calcium silicate, magnesium carbonate, magnesium oxide, talc, kaolin clay, calcined clay, zinc oxide, zinc sulfate, aluminum hydroxide, aluminum oxide, glass, mica, muscovite, Examples thereof include barium sulfate, alumina white, zeolite, silica balloon, and glass balloon.

  On the other hand, as the resin constituting the organic filler, for example, benzoguanamine resin, melamine resin, benzoguanamine-melamine resin, silicone resin, low density polyethylene, high density polyethylene, polyolefin resin, ethylene-acrylic copolymer, polystyrene, crosslinked polystyrene, Examples include polydivinylbenzene, styrene-divinylbenzene copolymer, acrylic copolymer, cross-linked acrylic resin, polymethyl methacrylate, vinylidene chloride resin, fluororesin, nylon, phenol resin, epoxy resin, urethane resin, and polyimide resin. The method for producing the filler comprising these resins is not particularly limited. For example, a method of synthesizing the resin and simultaneously forming particles by emulsion polymerization, suspension polymerization, emulsion dispersion, dispersion polymerization, or W / O microemulsion polymerization. And a method in which the synthesized resin is made into particles by a mechanical pulverization method or a chemical pulverization method. Further, these resins may have a functional group such as a halogen group, an epoxy group, an amino group, a hydroxyl group, a thiol group, an amide group, a carboxyl group, a phosphoric acid group, or a sulfonic acid group.

  Among the organic fillers, fluorine resin powder, urethane resin powder, acrylic resin powder, silicone resin powder, and polyethylene resin powder are preferable, and urethane resin powder and acrylic resin powder are more preferable.

  As said filler (D), said inorganic filler or organic filler can be used individually, or 2 or more types can also be used together. Moreover, you may use together an inorganic filler and an organic filler.

  The average particle size of the filler (D) is preferably in the range of 0.5 to 50 μm, more preferably in the range of 1 to 30 μm, and still more preferably in the range of 5 to 20 μm. If the average particle diameter of a filler (D) exists in this range, a softness | flexibility and abrasion resistance will become favorable. The average particle diameter is a median diameter (d50) obtained by measuring the particle size distribution by a laser diffraction / scattering method. Further, as a device for measuring the particle size distribution by the laser diffraction / scattering method, “Microtrac FRA” manufactured by Nikkiso Co., Ltd. can be used.

  In the leather surface finish of the present invention, the suitability for coating and high wear resistance can be improved by blending the filler (D). In addition, the gloss of the leather surface can be adjusted.

  Moreover, the range of 5-120 mass parts is preferable with respect to 100 mass parts of water-based polyurethane resin (A), and the range of 10-80 mass parts is more preferable. If the blending amount of the filler is within this range, the abrasion resistance of the leather is sufficient, and a soft texture of the leather can be secured.

  In the leather surface finish of the present invention, various additives such as a crosslinking accelerator, a colorant such as an organic pigment and an inorganic pigment, a flame retardant and an antioxidant, and an aqueous polyurethane resin are used within the scope of the present invention. Other resins can be added.

  By applying the leather surface finish of the present invention onto the leather surface layer, the outermost surface layer of the leather is subjected to coloring and gloss adjustment, tactile sensation, wear resistance, and the like. The surface strength can be improved. In particular, it is preferable to use the leather surface layer for leather made of polyurethane resin because the effect is great.

  Further, the leather of the present invention was formed by coating the surface finish for leather of the present invention on the surface of leather such as artificial leather, synthetic leather, natural leather, etc., and formed a surface finish layer on the surface of the leather. Is. The surface finish for leather of the present invention can be used for any of artificial leather, synthetic leather and natural leather, but is particularly suitable for artificial leather. In addition, when the surface finish for leather of the present invention is used for artificial leather, the materials such as the resin composition for the surface layer and the resin composition for the adhesive layer used for the production of the artificial leather are also considered in consideration of the burden on the environment. In particular, the material preferably does not contain an organic solvent, and an aqueous material is particularly preferable.

  Examples of a method for forming a film by applying the surface finish for leather of the present invention on the surface of leather include the following methods.

Examples of the method of coating the leather surface finish of the present invention on the leather surface include, for example, a direct spray method; a direct coating method such as a gravure coater, knife coater, comma coater, air knife coater, etc. The direct coating method using a gravure coater is most preferable. Further, the coating amount of the leather aqueous surface finish is coating amount after drying is preferably in a range to be 3 to 50 g / ^{m 2,} and more preferably range of the 5 to 30 g / ^{m 2.}

  The drying method after the application of the leather surface finish of the present invention is not particularly limited as long as it is necessary for the moisture in the resin composition to evaporate and the crosslinking reaction of the resin to occur. It is preferable to dry at 60 to 150 ° C. for about 10 seconds to 5 minutes. Further, it is more preferable to dry at 80 to 130 ° C. for about 30 seconds to 2 minutes. Further, it is more preferable that the film is aged at 40 ° C. for about one week after drying in order to completely advance the crosslinking reaction and obtain a high strength film.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

  The aqueous resin compositions (leather finishes for leather) used in Examples and Comparative Examples were prepared as follows.

(Synthesis Example 1)
By reacting 500 parts of polycarbonate diol (number average molecular weight 2000 in terms of polystyrene), 32 parts of 2,2-dimethylolpropionic acid, 147 parts of hexamethylene diisocyanate, 9 parts of 80% hydrazine hydrate, 25 parts of triethylamine, An aqueous polyurethane resin dispersion having a nonvolatile content of 35% and an acid value of 20 was obtained.

Example 1
100 parts by weight of aqueous polyurethane resin dispersion obtained in Synthesis Example 1 (35 parts by weight of non-volatile content), water-dispersible polyisocyanate-based cross-linking agent (“Hydran Assist C2” manufactured by Dainippon Ink & Chemicals, Inc., non-volatile content of 100 20 parts by mass), polyether-modified silicone ("Paintad 29" manufactured by Dow Corning Co., Ltd., 100% by mass of nonvolatile content) and urethane resin powder ("Art Pearl C-400 Tomei" manufactured by Negami Kogyo Co., Ltd.), average (Particle size 14 μm) 25 parts by mass was mixed with a homomixer to obtain an aqueous resin composition.

(Example 2)
In place of the urethane resin powder used in Example 1, acrylic resin powder (Matsumoto Yushi Seiyaku Co., Ltd. “Matsumoto Microsphere M-311”, average particle size 15 μm) was used in the same manner as in Example 1, An aqueous resin composition was obtained.

(Example 3)
It replaced with 25 mass parts of urethane resin powder used in Example 1, and carried out similarly to Example 1 except having used 10 mass parts of silica (Tosoh Silica Co., Ltd. "Nipgel AY-451", average particle diameter of 4 micrometers). An aqueous resin composition was obtained.

(Comparative Example 1)
Instead of 20 parts by mass of the water-dispersible polyisocyanate-based crosslinking agent used in Example 1, a polycarbodiimide aqueous dispersion (Dainippon Ink Chemical Co., Ltd. "Hydran Assist CS-7", nonvolatile content 40%) 50 Except having used the mass part, it carried out similarly to Example 1 and obtained the aqueous resin composition.

(Comparative Example 2)
An aqueous resin composition was obtained in the same manner as in Example 1 except that the amount of the water-dispersible polyisocyanate crosslinking agent used in Example 1 was changed from 20 parts by mass to 12 parts by mass.

(Comparative Example 3)
An aqueous resin composition was obtained in the same manner as in Example 1 except that the amount of the water-dispersible polyisocyanate-based crosslinking agent used in Example 1 was changed from 20 parts by mass to 40 parts by mass.

(Comparative Example 4)
An aqueous resin composition was obtained in the same manner as in Example 1 except that the amount of the polyether-modified silicone used in Example 1 was changed from 4 parts by mass to 1 part by mass.

(Comparative Example 5)
An aqueous resin composition was obtained in the same manner as in Example 1 except that the amount of the polyether-modified silicone used in Example 1 was changed from 4 parts by mass to 10 parts by mass.

(Comparative Example 6)
Except having changed the compounding quantity of the silica used in Example 3 from 10 mass parts to 1 mass part, it carried out similarly to Example 3 and obtained the aqueous resin composition.

(Comparative Example 7)
An aqueous resin composition was obtained in the same manner as in Example 1 except that the urethane resin powder blended in Example 1 was not blended.

(Production of fiber laminate)
According to the following procedures, a fiber laminate used for evaluation of the aqueous resin compositions obtained in the above Examples and Comparative Examples was produced.

A polyester non-woven fabric having a basis weight of 100 g / m ² , 62.5 parts by mass of a water dispersible polyurethane resin (“Hydran WLI-602” manufactured by Dainippon Ink & Chemicals, Inc.), a thickener (manufactured by Dainippon Ink & Chemicals, Inc. Hydran Assister T2 ") 0.5 parts by weight, a coloring agent (Dailac Black HP-9451, manufactured by Dainippon Ink & Chemicals, Inc.) 2 parts by weight, and impregnated with a blended liquid containing 35 parts by weight of water, Mungle rolls were squeezed to a wet pickup of 150%. Immediately after squeezing, the polyurethane resin was coagulated by exposure to 95 ° C. steam for 1 minute. Subsequently, it dried for 30 minutes with a 100 degreeC dryer, and obtained the fiber base material.

  100 parts by mass of a water-dispersible polyurethane resin (Dainippon Ink & Chemicals, Ltd. “Hydran WLS-210”), 10 parts by mass of a colorant (Dailac Black HS-9540, manufactured by Dainippon Ink & Chemicals, Inc.), water 4 parts by mass of a dispersible polyisocyanate-based cross-linking agent (Dainippon Ink Chemical Co., Ltd. “Hydran Assister C2”) and associative thickener (Dainippon Ink Chemical Co., Ltd. “Hydran Assister T1”) 0 The coating material for the surface layer of the fiber laminate containing 5 parts by mass was applied on a release paper (“DN-AT-AP-T flat” manufactured by Dai Nippon Printing Co., Ltd.) with a coating thickness of 100 μm (WET). Immediately using a Warner Mathis (dryer), pre-drying at 70 ° C. for 1 minute, followed by drying at 120 ° C. for 2 minutes to completely evaporate the water, and a polyurethane resin film (hereinafter referred to as “surface layer”) is obtained. It was.

  On the surface layer obtained above, 100 parts by mass of a water-dispersible polyurethane resin (“Hydran WLA-311” manufactured by Dainippon Ink & Chemicals, Inc.), a water-dispersible polyisocyanate-based crosslinking agent (Dainippon Ink and Chemicals, Inc.) Coated thickness of polyurethane adhesive compounded with 10 parts by weight of “Hydran Assister C2” manufactured by Co., Ltd. and 1 part by weight of associative thickener (“Hydran Assister T1” manufactured by Dainippon Ink & Chemicals, Inc.) The coating was performed at 120 μm (WET). Next, drying was performed at 70 ° C. for 1 minute using Warner Mathis, and immediately after drying, the fiber base material obtained above was bonded thereon. Thereafter, curing was performed at 120 ° C. for 2 minutes, aging was further performed at 40 ° C. for 2 days, and the release paper was peeled off to obtain a fiber laminate.

(Production of artificial leather for evaluation)
On the surface layer of the fiber laminate obtained above, the aqueous resin composition obtained in Examples and Comparative Examples using an 80 mesh gravure coater was used as a leather surface finish, and the coating amount after drying was It applied so that it might become 5-15 g / m < ² >, and it was made to dry with hot air at 80 degreeC for 2 minutes. Subsequently, the artificial leather for evaluation was obtained by aging at 40 ° C. for 1 week.

  The artificial leather for evaluation obtained above was evaluated by the following method.

(Coating suitability)
The repelling state of the aqueous resin composition when the aqueous resin composition was coated on the surface layer of the fiber laminate with a gravure coater was visually confirmed and evaluated according to the following criteria.
○: No repelling ×: With repelling

(Smooth surface)
The surface of the obtained artificial leather was measured for gloss using a variable angle gloss meter (“MMX-202” manufactured by Murakami Color Research Laboratory Co., Ltd., measurement angle 60 degrees) and evaluated according to the following criteria.
○: Gloss value less than 1.5 ×: Gloss value 1.5 or more

(Abrasion resistance)
The obtained artificial leather was subjected to a Taber abrasion test in accordance with JIS K 7204: 1999 using a Taber abrasion tester (“Taber Ablation Tester” manufactured by Yasuda Seiki Seisakusho Co., Ltd.). , Load: 9.8 N, wear frequency: 1,000 times. From the obtained results, the wear resistance was evaluated according to the following criteria.
○: Almost no change in appearance before and after the wear test.
(Triangle | delta): There is an abrasion trace on the surface of artificial leather after an abrasion test, and there is some whitening.
X: The surface of the artificial leather is worn and whitened after the wear test.

  The evaluation results of the examples are shown in Table 1, and the evaluation results of the comparative examples are shown in Table 2.

  It was found that the leather surface finishes of the present invention obtained in Examples 1 to 3 had good coating suitability. Moreover, it turned out that the artificial leather using the surface finish for leathers of this invention has high surface matteness and abrasion resistance.

  Comparative Example 1 is an example using a polycarbodiimide system instead of a polyisocyanate system as a crosslinking agent. The leather surface finish of Comparative Example 1 had relatively good coating suitability and surface matting properties, but was insufficient in abrasion resistance.

  Comparative Example 2 is an example in which the blending amount of the polyisocyanate crosslinking agent is less than the specified value of the present invention. The leather surface finish of Comparative Example 2 had relatively good coating suitability and surface matting properties, but was insufficient in abrasion resistance.

  Comparative Example 3 is an example in which the blending amount of the polyisocyanate-based crosslinking agent is larger than the specified value of the present invention. The leather surface finish of Comparative Example 3 had relatively good coating suitability and surface matting properties, but was insufficient in abrasion resistance.

  Comparative Example 4 is an example in which the compounding amount of the silicone compound is less than the specified value of the present invention. The surface finish for leather of Comparative Example 4 had relatively good coating suitability and surface matting properties, but was insufficient in wear resistance.

  Comparative Example 5 is an example in which the compounding amount of the silicone compound is larger than the specified value of the present invention. The leather surface finish of Comparative Example 5 had relatively good coating suitability and surface matting properties, but was insufficient in abrasion resistance.

  Comparative Example 6 is an example in which the filler content is less than the specified value of the present invention. The leather surface finish of Comparative Example 6 had relatively good coating suitability, but had insufficient surface matting and wear resistance.

The comparative example 7 is an example which did not mix | blend a filler. The leather surface finish of Comparative Example 7 was insufficient in coating suitability, surface matteness and wear resistance.

Claims (3)

Aqueous polyurethane resin (A) 100 parts by weight, polyisocyanate-based crosslinking agent (B) 40-100 parts by weight, silicone-based compound (C) 5-25 parts by weight, and filler (D) 5-120 parts by weight A surface finish for leather, comprising a resin composition. The surface finish for leather according to claim 1, wherein the silicone compound (C) is a polyether-modified silicone. A leather comprising a coating film comprising the surface finish for leather according to claim 1 or 2 on the surface.