JP4452139B2 - Method for manufacturing leather materials - Google Patents

Description

  The present invention relates to a method for producing a leather material and a leather material, and more particularly, the present invention relates to a method for producing a leather material that can be suitably used as artificial leather or synthetic leather by using an aqueous polyurethane resin. Regarding materials.

  Conventionally, as a substitute for natural leather, many kinds of artificial leather made of fiber base material made of polyurethane resin and nonwoven fabric and synthetic leather made of fiber base material made of polyurethane resin and woven fabric or knitted fabric have been manufactured. It is coming. Such artificial leather and synthetic leather are, for example, those obtained by impregnating or coating a fiber base material with an organic solvent solution of polyurethane resin in order to resemble natural leather. It was produced by a method called a wet coagulation method in which it was coagulated by passing it through a coagulation liquid (usually water) compatible with water, followed by washing with water and drying.

  However, organic solvents such as dimethylformamide, which are often used in such wet coagulation methods, are highly flammable and highly toxic. There were also concerns about environmental pollution such as air quality and water quality. And although the manufacturing method incorporating the process of collect | recovering the organic solvent which generate | occur | produces in order to eliminate such a problem is performed, the problem that a lot of disposal cost and labor are applied remained. In addition, in artificial leather and synthetic leather obtained by using an organic solvent solution of polyurethane resin, since the organic solvent remains in the leather, the influence on the human body such as skin damage has been a problem. Therefore, studies have been made to shift the polyurethane resin fixed to the fiber base material from an organic solvent type to an aqueous polyurethane resin.

  The manufacturing method of artificial leather and the like using such an aqueous polyurethane resin does not use an organic solvent, so that the cost required for recovery can be eliminated, and improvement of the working environment, environmental pollution, water pollution, etc. However, when compared with artificial leather and synthetic leather obtained using an organic solvent solution of polyurethane resin, artificial leather and synthetic leather having satisfactory texture and physical properties were not obtained. A major cause of such a problem is that when the aqueous polyurethane resin is impregnated inside the fiber base material and then dried by hot air with hot air, the aqueous polyurethane resin is caused by the movement of water evaporated from the fiber base surface. There is a so-called migration that shifts to the surface of the fiber base material. In other words, when such migration occurs, in a method for manufacturing artificial leather using an aqueous polyurethane resin, the aqueous polyurethane resin moves to the surface of the fiber base material, and the polyurethane resin is almost fixed inside the fiber base material. It was in a state of not being made, and it was an artificial leather and a synthetic leather with a hard texture and a poor feeling of napping. Therefore, in the manufacturing method of artificial leather or the like using an aqueous polyurethane resin, various studies have been made to solve the migration problem.

  For example, Japanese Patent Publication No. 55-51076 (Patent Document 1) discloses a method of coagulating a synthetic resin emulsion to which a heat-sensitive gelling agent has been added to impart heat-sensitive coagulation properties in hot water.

  However, in such a method, although the migration prevention property is improved, a part of the impregnating liquid flows out into the bath and solidifies, and the solidified gel is reattached to the surface of the work piece to obtain the obtained leather. There was a problem that the texture of the lumber deteriorated. Further, in such a method, as the polyurethane resin concentration decreases, the heat-sensitive coagulation property decreases, and part of the impregnating liquid tends to flow into the hot water, and the texture of the resulting leather material further deteriorates. There was also a problem of end up.

  Japanese Patent Application Laid-Open No. 6-316877 (Patent Document 2) discloses a method of applying a water-based resin composition in which an inorganic salt is dissolved to a forcedly emulsified emulsion and drying by heating.

  However, in such a method, although the migration prevention property is improved, there is a processing problem that the stability of the treatment bath is deteriorated due to the concentration of the inorganic salt to be blended. In addition, since nonionic surfactants and inorganic salts remain in the fiber base material, the resulting leather material has a rough texture, low wear resistance, and insufficient friction fastness. It was.

  Furthermore, in Japanese Patent Application Laid-Open No. 2000-290879 (Patent Document 3), there is a method in which a water-based resin composition comprising a water-based urethane resin having a heat-sensitive coagulation temperature of 40 to 90 ° C. and an associative thickener is heat-coagulated with steam. It is disclosed.

  However, in such a method, although the anti-migration property is improved, since the nonionic surfactant and the associative thickener remain in the fiber base material, the obtained leather material has a rough texture. Therefore, the wear resistance was low and the friction fastness was not sufficient.

  Japanese Patent Application Laid-Open No. 2003-138131 (Patent Document 4) discloses a method in which a carboxylate-type polyurethane resin containing a nonionic surfactant having an HLB of 10 to 18 and an inorganic salt is applied to a fiber material substrate and thermally coagulated. It is disclosed.

  However, even in such a method, problems due to surfactants and inorganic salts occur as in the methods described in Patent Documents 2 and 3, and the obtained leather material has a coarse texture and wear resistance. However, the fastness to friction was not sufficient.

  In the methods described in Patent Documents 2 to 4, residues such as nonionic surfactants, associative thickeners and inorganic salts can be removed by a process such as water washing or hot water washing. If such processes are added, the number of processing steps increases, resulting in economic problems. Therefore, a manufacturing method that can obtain a leather material having sufficient texture and physical properties without adding a process of washing the residue with water or hot water is required. Has been.

In this way, in the manufacturing method of artificial leather and the like using water-based polyurethane resin, it is possible to manufacture leather materials with sufficient texture and quality while sufficiently preventing polyurethane migration and fixing the polyurethane resin uniformly to the fiber substrate. At present, no method has been obtained.
Japanese Patent Publication No. 55-51076 JP-A-6-316877 JP 2000-290879 A JP 2003-138131 A

  The present invention has been made in view of the above-mentioned problems of the prior art, and despite the fact that it is a method for manufacturing a leather material using a water-based polyurethane resin in consideration of environmental load and VOC problems, sufficient migration is achieved. A method for producing a leather material capable of preventing and efficiently and reliably obtaining a leather material having a soft texture and excellent physical properties such as wear resistance and friction fastness, and It aims at providing the leather material obtained by a manufacturing method.

  As a result of intensive studies to achieve the above object, the present inventors have impregnated a mixed liquid containing a specific aqueous polyurethane resin, a specific organic acid salt and water, and then dried the mixture. It was found that the polyurethane resin adheres evenly to the inside of the fiber base material without migration and uneven distribution of the water-based polyurethane resin during drying, and a leather material having a soft texture and sufficient physical properties can be obtained. Based on this, the present invention has been completed.

That is, the method for producing a leather material of the present invention uses (A) a carboxyl group-containing polyurethane resin, (B) a mixed solution containing an ammonium salt of a carboxylic acid having 1 to 18 carbon atoms and (C) water as a fiber base material. After impregnating, it is dried to obtain a leather material.

  As said mixed liquid concerning the said invention, the compounding ratio of (A) carboxyl group-containing polyurethane resin and (B) ammonium salt of carboxylic acid is (A) :( B) = 100: It is preferable that it is 0.1-100: 20.

  The (A) carboxyl group-containing polyurethane resin according to the present invention includes (a) an organic diisocyanate, (b) a polyol, and (c) a carboxyl obtained by reacting a compound having a carboxyl group and two or more active hydrogens. It is obtained by neutralizing the group-containing isocyanate group-terminated prepolymer and emulsifying and dispersing it in water by self-emulsification, and then (d) chain-extending reaction using a polyamine compound having two or more amino groups and / or imino groups. A carboxyl group-containing polyurethane resin is preferred.

  As content of the carboxyl group in the (A) carboxyl group-containing polyurethane resin concerning the said invention, it is preferable that it is 0.5-4.0 mass%.

  The value of 100% modulus of the (A) carboxyl group-containing polyurethane resin according to the present invention is preferably 1 to 9 MPa.

  The carboxylic acid in the ammonium salt of (B) carboxylic acid according to the present invention is preferably a carboxylic acid having 1 to 10 carbon atoms.

  The mixed solution according to the present invention preferably has a pH value of 7.0 to 9.0 and a coagulation temperature of 30 to 70 ° C.

  According to the present invention, it is possible to sufficiently prevent migration in spite of the manufacturing method of leather material using water-based polyurethane resin in consideration of environmental load and VOC problem. It is possible to provide a method for producing a leather material capable of efficiently and reliably obtaining a leather material having excellent physical properties such as wear and friction fastness, and a leather material obtained by the production method. It becomes.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

In the method for producing a leather material of the present invention, a fiber base material is impregnated with (A) a carboxyl group-containing polyurethane resin, (B) an ammonium salt of a carboxylic acid having 1 to 18 carbon atoms and (C) water. And then drying to obtain a leather material.

  The (A) carboxyl group-containing polyurethane resin according to the present invention is a polyurethane resin containing a carboxyl group as a hydrophilic component in the urethane resin skeleton. As such (A) carboxyl group-containing polyurethane resin, (a) an organic diisocyanate, (b) a polyol, and (c) a carboxyl group-containing product obtained by reacting a compound having a carboxyl group and two or more active hydrogens. A carboxyl obtained by neutralizing an isocyanate group-terminated prepolymer and emulsifying and dispersing it in water by self-emulsification, and then (d) chain-extending reaction using a polyamine compound having two or more amino groups and / or imino groups A group-containing polyurethane resin can be suitably used.

  There is no restriction | limiting in particular as such (a) organic diisocyanate, The aliphatic diisocyanate, alicyclic diisocyanate, and aromatic diisocyanate which have two isocyanate groups can be used. Examples of such (a) organic diisocyanate include aliphatic diisocyanate compounds such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, dicyclohexylmethane diisocyanate, norbornane diisocyanate, and 1,3-bis ( Examples thereof include alicyclic diisocyanate compounds such as isocyanatomethyl) cyclohexane, aromatic diisocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, tolidine diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate. These diisocyanate compounds can be used individually by 1 type, or can also be used in combination of 2 or more type. Among these (a) organic diisocyanates, aliphatic diisocyanate compounds and alicyclic diisocyanate compounds can be suitably used because they impart non-yellowing properties to leather materials, and in particular, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate. Norbornane diisocyanate and 1,3-bis (isocyanatomethyl) cyclohexane can be preferably used.

  The (b) polyol is not particularly limited as long as it has two or more hydroxyl groups, and is a polyether ester having an ether bond and an ester bond in addition to a polyester polyol, a polycarbonate polyol, a polyether polyol, and the like. Polyols can also be used.

  Examples of such polyester polyols include polyethylene adipate, polybutylene adipate, polyethylene butylene adipate, polyhexamethylene isophthalate adipate, polyethylene succinate, polybutylene succinate, polyethylene sebacate, polybutylene sebacate, poly-ε- Caprolactone diol, poly (3-methyl-1,5-pentylene) adipate, polycondensate of 1,6-hexanediol and dimer acid, copolycondensate of 1,6-hexanediol, adipic acid and dimer acid, nonane Examples thereof include polycondensates of diol and dimer acid, and copolycondensates of ethylene glycol, adipic acid and dimer acid.

  Examples of the polycarbonate polyol include polytetramethylene carbonate diol, polyhexamethylene carbonate diol, poly-1,4-cyclohexanedimethylene carbonate diol, and 1,6-hexanediol polycarbonate polyol.

  Furthermore, as the polyether polyol, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol homopolymer, block copolymer, random copolymer, ethylene oxide and propylene oxide, ethylene oxide and butylene oxide random copolymer And a block copolymer.

  Moreover, such (b) polyol can be used individually by 1 type, or can also be used in combination of 2 or more type. Furthermore, as an average molecular weight of such (b) polyol, it is preferable that it is 500-5000, and it is more preferable that it is 1000-3000. In addition, from the viewpoint that the obtained carboxyl group-containing polyurethane resin can impart sufficient durability to the leather material, it is preferable to use a polycarbonate polyol or a polyether polyol as the above-mentioned (b) polyol.

  Examples of the compound (c) having a carboxyl group and two or more active hydrogens include 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid. Further, as a compound having such a carboxyl group and two or more active hydrogens, it has a pendant type carboxyl group obtained by reacting a diol having a carboxyl group with an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid or the like. Polyester polyol can also be used. In place of the diol having a carboxyl group, a diol having no carboxyl group may be mixed and reacted as a diol component. Moreover, the compound which has such a carboxyl group and two or more active hydrogens can be used individually by 1 type, or can also be used in combination of 2 or more type.

  In addition, when producing an isocyanate group-terminated prepolymer by reacting (a) an organic diisocyanate, (b) a polyol, and (c) a compound having a carboxyl group and two or more active hydrogens, 2 is added as necessary. Low molecular weight chain extenders having more than one active hydrogen atom can be used.

  As such a low molecular weight chain extender having two or more active hydrogen atoms, the molecular weight is preferably 400 or less, and particularly preferably 300 or less. Such low molecular weight chain extenders include, for example, ethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, pentaerythritol, sorbitol and the like. Molecular weight polyhydric alcohols; low molecular weight polyamines such as ethylenediamine, propylenediamine, hexamethylenediamine, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine, diethylenetriamine, and triethylenetetramine. Further, such low molecular weight chain extenders having two or more active hydrogen atoms can be used alone or in combination of two or more.

  In the present invention, the specific method for producing the carboxyl group-containing isocyanate group-terminated prepolymer is not particularly limited. For example, it is produced by a conventionally known one-stage so-called one-shot method, multi-stage isocyanate polyaddition reaction method or the like. can do. The reaction temperature at this time is preferably 40 to 150 ° C. In addition, a reaction catalyst such as dibutyltin dilaurate, stannous octoate, dibutyltin-2-ethylhexanoate, triethylamine, triethylenediamine, N-methylmorpholine may be added as necessary during such a reaction. Can do. Moreover, the organic solvent which does not react with an isocyanate group can be added during reaction or after completion | finish of reaction. As such an organic solvent, for example, acetone, methyl ethyl ketone, toluene, tetrahydrofuran, dioxane, dimethylformamide, N-methylpyrrolidone and the like can be used.

  Further, in the present invention, neutralization of the carboxyl group-containing isocyanate group-terminated prepolymer can be performed using a known method as appropriate before or after the preparation of the carboxyl group-containing isocyanate group-terminated prepolymer. There is no restriction | limiting in particular in the compound used for neutralization of such carboxyl group-containing isocyanate group terminal prepolymer, For example, trimethylamine, triethylamine, tri-n-propylamine, tributylamine, N-methyl-diethanolamine, N, N- Examples thereof include amines such as dimethylmonoethanolamine, N, N-diethylmonoethanolamine, and triethanolamine, potassium hydroxide, sodium hydroxide, and ammonia. Among such compounds, tertiary amines having no hydroxyl group such as trimethylamine, triethylamine, tri-n-propylamine, and tributylamine are particularly preferable.

  In the present invention, there are no particular limitations on the emulsifying equipment used when the neutralized product of the carboxyl group-containing isocyanate group-terminated prepolymer is emulsified and dispersed in water, and examples thereof include a homomixer, a homogenizer, and a disper. In addition, when the neutralized product of the carboxyl group-containing isocyanate group-terminated prepolymer is emulsified and dispersed in water, the neutralized product of the carboxyl group-containing isocyanate group-terminated prepolymer is used at a temperature of room temperature to 40 ° C. without using an emulsifier. It is preferable that the reaction between the isocyanate group and water is suppressed as much as possible by emulsifying and dispersing in water. Furthermore, when emulsifying and dispersing in this way, reaction inhibitors such as phosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, paratoluenesulfonic acid, adipic acid, benzoyl chloride are added as necessary. be able to.

  Furthermore, in the present invention, a neutralized product of carboxyl group-containing isocyanate group-terminated prepolymer is emulsified and dispersed in water, and then (d) a chain extension reaction using a polyamine compound having two or more amino groups and / or imino groups. By doing so, an emulsified dispersion of the target (A) carboxyl group-containing polyurethane resin can be obtained.

  Examples of such (d) polyamine compounds having two or more amino groups and / or imino groups include ethylenediamine, propylenediamine, tetramethylenediamine, hexamethylenediamine, diaminocyclohexylmethane, piperazine, hydrazine, and 2-methylpiperazine. Diamines such as isophoronediamine, norbornanediamine, diaminodiphenylmethane, tolylenediamine, xylylenediamine; polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, tris (2-aminoethyl) amine; Amidoamines derived from primary amines and monocarboxylic acids; water-soluble amine derivatives such as monoketimines of diprimary amines; oxalic acid dihydrazide, malonic acid dihydrazide Oxalic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, 1,1'-ethylenehydrazine, 1,1'-trimethylenehydrazine, 1,1 ' Examples include hydrazine derivatives such as-(1,4-butylene) dihydrazine. These polyamine compounds having two or more amino groups and / or imino groups can be used singly or in combination of two or more.

  In the present invention, the chain elongation reaction of the neutralized product of the carboxyl group-containing isocyanate group-terminated prepolymer is carried out by adding (d) an amino group and an emulsion dispersion of the neutralized product of the carboxyl group-containing isocyanate group-terminated prepolymer described above. It can be carried out by adding a polyamine compound having two or more imino groups. Further, (d) an emulsified dispersion of a neutralized product of the carboxyl group-containing isocyanate group-terminated prepolymer described above may be added to a polyamine compound having two or more amino groups and / or imino groups. The chain extension reaction is preferably performed at a reaction temperature of 20 to 40 ° C., and is usually completed in 30 to 120 minutes. When an organic solvent is used in producing the carboxyl group-containing isocyanate group-terminated prepolymer, it is preferable to remove the organic solvent by, for example, vacuum distillation after the chain extension reaction is completed.

  In the present invention, the value of 100% modulus of the (A) carboxyl group-containing polyurethane resin is preferably 1 to 9 MPa, and more preferably 2 to 6 MPa. When the value of 100% modulus is less than 1 MPa, a leather material with a soft texture can be obtained, but the wear resistance tends to be weak, and when it exceeds 9 MPa, the texture of the obtained leather material becomes hard. There is a tendency. Here, the value of 100% modulus was measured according to JIS K 6251 (1993), and when the distance between marked lines was increased by 100% using a dumbbell-shaped No. 3 test piece (doubled). A predetermined elongation tensile stress (MPa).

  Moreover, in this invention, it is preferable that it is 0.5-4.0 mass% as content of the carboxyl group in (A) carboxyl group-containing polyurethane resin, and is 1.0-2.0 mass%. It is more preferable. When the carboxyl group content is less than 0.5% by mass, the storage stability of the resulting (A) carboxyl group-containing polyurethane resin tends to deteriorate, while when it exceeds 4.0% by mass, (B ) The heat-sensitive coagulation temperature generated when mixed with the carboxylic acid ammonia salt tends to be high, and the effect of preventing migration tends to be weak during the production of leather materials.

  Furthermore, in the present invention, (A) the carboxyl group-containing polyurethane resin is preferably retained in the form of an emulsion dispersion, and the pH value is preferably 7.0 to 9.0, and 7.5 to 8 .5 is more preferable. If the pH value is less than 7.0, the storage stability of the emulsified dispersion of (A) carboxyl group-containing polyurethane resin tends to be poor, and if the pH value exceeds 9.0, it prevents migration during the production of leather materials. It tends to be less effective.

  Moreover, it does not restrict | limit especially as (B) ammonium salt of carboxylic acid concerning this invention, What is marketed can also be used. Examples of the carboxylic acid in the ammonium salt of (B) carboxylic acid include saturated fatty acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, capric acid and stearic acid; non-oleic acids such as oleic acid and linoleic acid. Saturated fatty acids; aromatic carboxylic acids such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid; saturated dicarboxylic acids such as malic acid, citric acid, succinic acid, malonic acid, succinic acid, adipic acid; fumaric acid, maleic acid, etc. Unsaturated dicarboxylic acid; lactic acid, acrylic acid, polyacrylic acid, polymaleic acid and the like. Among such ammonium salts of (B) carboxylic acid, it can be easily removed by impregnation of the mixed solution, migration prevention of the carboxyl group-containing polyurethane resin during the drying process, and volatilization during drying or washing with water after drying. From the viewpoint that it is less likely to remain in the obtained leather material, a carboxylic acid having 1 to 10 carbon atoms can be suitably used, and a carboxylic acid having 1 to 4 carbon atoms can be more suitably used.

  In the method for producing a leather material of the present invention, when (B) the ammonium salt of carboxylic acid is mixed with the emulsion dispersion of (A) carboxyl group-containing polyurethane resin, (B) the ammonium salt of carboxylic acid is solid (powder). It is also possible to mix with the emulsion dispersion of (A) carboxyl group-containing polyurethane resin in the state of (body), but from the viewpoint of maintaining the stability of the emulsion dispersion of (A) carboxyl group-containing polyurethane resin ( B) It is preferable to mix the ammonium salt of carboxylic acid in the state of aqueous solution.

  In such an aqueous solution of the ammonium salt of (B) carboxylic acid, the concentration of the ammonium salt of carboxylic acid is preferably 1 to 50% by mass, and more preferably 10 to 30% by mass. In the case of an aqueous solution having a concentration of ammonium salt of carboxylic acid in the aqueous solution of less than 1% by mass, it is mixed with an emulsified dispersion of (A) a carboxyl group-containing polyurethane resin in order to exhibit migration prevention properties during drying. In this case, it is necessary to add a large amount of the aqueous solution, and accordingly, the concentration of the (A) carboxyl group-containing polyurethane resin in the mixed solution is lowered. Therefore, in order to fix the required amount of carboxyl group-containing polyurethane resin to the fiber base material, it is necessary to impregnate the fiber base material with a large amount of liquid mixture, and the amount of water volatilized during drying increases, so the drying time is increased. There is a tendency for the economy to become longer and worse. On the other hand, when the concentration of the ammonium salt of the carboxylic acid in the aqueous solution exceeds 50% by mass, the stability of the emulsified dispersion is improved, for example, precipitates are generated upon mixing with the emulsified dispersion of (A) carboxyl group-containing polyurethane resin. There is a tendency to lose.

  Moreover, as pH value of such ammonium salt aqueous solution of carboxylic acid, it is preferable that it is 7.0-9.0, and it is more preferable that it is 7.5-8.5. When the pH value is less than 7.0, precipitates tend to be generated during mixing with the emulsion dispersion of (A) carboxyl group-containing polyurethane resin. On the other hand, when the pH value exceeds 9.0, in the drying step The migration prevention effect tends to be weakened.

  In addition, (C) water according to the present invention has a role as a solvent when mixing (A) a carboxyl group-containing polyurethane resin and (B) an ammonium salt of carboxylic acid. Water can be preferably used.

  In the present invention, the method for preparing a mixed solution containing (A) a carboxyl group-containing polyurethane resin, (B) an ammonium salt of carboxylic acid and (C) water is not particularly limited, and a known method can be used as appropriate. .

  Moreover, in the said liquid mixture, as a compounding ratio of (A) carboxyl group-containing polyurethane resin and (B) ammonium salt of carboxylic acid, it is (A) :( B) = 100: 0.5 in conversion of the mass of solid content. ˜100: 20 is preferable, and 100: 2 to 100: 10 is more preferable. When the blending ratio exceeds 100: 0.5, that is, when the blending ratio of the carboxylic acid ammonium salt is less than 0.5, the effect of preventing migration during the drying process tends to be weakened. Is less than 100: 20, that is, when the mixing ratio of the ammonium salt of carboxylic acid is more than 20, the mixed solution tends to gel in the summer temperature atmosphere.

  Furthermore, the heat-sensitive coagulation temperature of the mixed solution is preferably 30 to 70 ° C, and more preferably 40 to 60 ° C. Here, the thermal coagulation temperature means that 50 g of the above mixture is placed in a 100 mL glass beaker and the contents are fluidized while the contents are stirred and gradually heated in a 95 ° C. hot water bath. It is the temperature at which it loses and solidifies. When the heat-sensitive coagulation temperature is less than 30 ° C, the mixed solution tends to gel in the summer atmosphere, and when it exceeds 80 ° C, the heat-sensitive coagulation does not appear sharply. In this case, the migration prevention property tends to be weak.

  Moreover, as content of (A) carboxyl group-containing polyurethane resin in the said liquid mixture, it is preferable that it is 15-35 mass%, and it is more preferable that it is 20-30 mass%. If the content of the carboxyl group-containing polyurethane resin is less than 15% by mass, the fiber substrate is impregnated with a large amount of the liquid mixture in order to fix the necessary amount of the polyurethane resin. There is a tendency that the amount of water to be increased increases the drying time, resulting in poor economic efficiency. On the other hand, when the content of the carboxyl group-containing polyurethane resin exceeds 35% by mass, the stability of the mixed solution tends to deteriorate.

  Moreover, as a pH value of the said liquid mixture, it is preferable that it is 7.0-9.0, and it is more preferable that it is 7.5-8.5. When the pH value of the mixed solution is less than 7.0, the stability of the mixed solution tends to deteriorate. On the other hand, when the pH value exceeds 9.0, the migration preventing effect tends to be weakened in the drying process. is there.

  Furthermore, the fiber substrate according to the present invention is not particularly limited, and a woven fabric, a knitted fabric, a nonwoven fabric, or the like can be suitably used. As such a fiber base material, a texture and quality close to those of natural leather can be obtained, and those using polyamide fibers or polyester fibers are preferably used.

  Moreover, in the said nonwoven fabric used as the said fiber base material, it is preferable that the thickness of the thread | yarn of a nonwoven fabric is 2.0 dtex or less from a viewpoint that the texture of the leather material obtained improves. When the thickness of the nonwoven fabric thread exceeds 2.0 dtex, the texture of the leather material becomes coarse and hard, and the quality tends to be impaired.

As the density of such a nonwoven fabric is preferably 0.2 to 0.7 g / cm ^3, more preferably 0.30~0.55g / cm ^3. If the density of the non-woven fabric is less than 0.2 g / cm ³ , the resulting leather material tends to have poor wear resistance, and if a large amount of polyurethane resin is fixed to make up for it, the resulting leather material There is a tendency that the texture becomes coarse and hard and the quality is impaired. On the other hand, when the density of the nonwoven fabric exceeds 0.7 g / cm ³ , the texture of the obtained leather material tends to be coarse and hard, and the quality tends to be impaired.

  In the method for producing a leather material of the present invention, the mixed solution containing (A) a carboxyl group-containing polyurethane resin, (B) an ammonium salt of carboxylic acid and (C) water is processed within a range not impairing the object of the present invention. Various additives can be used in combination to impart suitability, such as lower alcohols, glycol solvents, alcohol-based nonionic surfactants, acetylene glycol-based special surfactants, and silicone-based surfactants. , Various penetrants such as fluorine-based surfactants; various stabilizers such as antioxidants, light-resistant stabilizers, UV-preventing agents; various antifoaming agents such as mineral oils and silicones; urethanization catalysts, plastics A colorant such as a colorant and a pigment, a pot life extender and the like can be added. Such an additive can be used individually by 1 type, or can also be used in combination of 2 or more type.

  Of these additives, it is particularly preferable to use a penetrant in combination. This is because the use of a penetrant makes it possible to quickly impregnate the fiber base material with the mixed liquid and to obtain an effect of uniformly fixing the polyurethane resin to the fiber base material. Such a penetrating agent is not particularly limited as long as it is generally used, but it is particularly preferable to use a lower alcohol, a glycol solvent, an alcohol nonionic surfactant, or the like.

  Further, in the method for producing a leather material of the present invention, the range in which the object of the present invention is not impaired in a mixed solution containing (A) a carboxyl group-containing polyurethane resin, (B) an ammonium salt of carboxylic acid and (C) water. In order to impart processability, a crosslinking agent that reacts with a carboxyl group can be used in combination. Examples of such crosslinking agents include oxazoline crosslinking agents, epoxy crosslinking agents, isocyanate crosslinking agents, carbodiimide crosslinking agents, and the like. These crosslinking agents can be used individually by 1 type, or can also be used in combination of 2 or more type.

  In the method for producing a leather material of the present invention, a mixed liquid containing (A) a carboxyl group-containing polyurethane resin, (B) an ammonium salt of carboxylic acid and (C) water is applied to a fiber substrate such as a woven fabric, a knitted fabric or a non-woven fabric. Dry after impregnation.

  The method for impregnating the fibrous base material with the mixed liquid is not particularly limited, and conventionally known methods such as impregnation processing and spraying treatment using a dip-nip method can be preferably employed, and the concentration of the mixed liquid In addition, processing conditions and the like can be appropriately selected. In addition, before impregnating fiber base materials, such as a woven fabric, a knitted fabric, and a nonwoven fabric, into a fiber base material (A) carboxyl group-containing polyurethane resin, (B) ammonium salt of carboxylic acid, and (C) water, Pre-processing can be performed. In such a pretreatment process, in order to adjust the adhesive force between the fiber base material and the polyurethane resin component, a polymer aqueous solution composed of polyvinyl alcohol, carboxymethyl cellulose, etc., a silicone water repellent, a fluorine water repellent, etc. It is preferred to use to treat the fiber substrate.

  Further, in the method for producing a leather material of the present invention, the method of drying after impregnating the mixed solution into the fiber base is not particularly limited, and for example, dry drying using hot air; high tenpulcher steamer ( HTS), wet drying using a high pressure steamer (HPS); microwave irradiation drying, etc. can be used, and dry drying using hot air in terms of continuous processability. It can be used suitably. These drying methods can be used individually by 1 type, or can also be used in combination of 2 or more type. Moreover, when using the dry drying using the said hot air, it is preferable that the processing temperature shall be 60-190 degreeC, and processing time shall be 1 to 20 minutes, especially, processing temperature shall be 100-170 degreeC, and processing time. Is preferably 2 to 5 minutes. By performing such drying, the polyurethane resin can be fixed inside the fiber base material.

  Thus, after impregnating the fiber base material with the mixed solution containing (A) carboxyl group-containing polyurethane resin, (B) ammonium salt of carboxylic acid and (C) water, the leather material of the present invention is dried. Obtainable.

  In such a leather material of the present invention, the amount of solid solids such as polyurethane resin in the leather material is not particularly limited, but the component derived from the (A) carboxyl group-containing polyurethane resin is 10 to 90 in the leather material. It is preferable that the component derived from the mass% and the ammonium salt of (B) carboxylic acid is about 0.5 to 7.0 mass%.

  Moreover, the leather material obtained by the present invention can be dyed. There is no particular limitation on such a dyeing method, and a dyeing method after impregnation after dyeing after fixing the polyurethane resin to the fiber base material, and a dyeing method after impregnation after fixing the polyurethane resin after dyeing the fiber base material Any of the methods can be performed.

  Furthermore, the leather material obtained according to the present invention can also be formed into a leather material with a silver surface by forming a skin layer. The method for forming such a skin layer is not particularly limited and may be any conventionally known method. For example, it is applied to a release paper, and the skin layer is formed by evaporating moisture, and further adhered thereon. A release agent transfer method in which the agent is applied and then directly laminated with the leather material of the present invention to evaporate the moisture, or after the moisture evaporates; the release layer is applied to the release paper and the moisture is evaporated to form a skin layer; Thermal transfer method in which the skin layer is bonded to the leather material of the present invention by heat; spray method of directly spraying on the leather material of the present invention; gravure coater, knife coater, comma coater, air knife coater, etc. on the leather material of the present invention The direct coating method etc. which apply | coat are mentioned. Among such methods for forming the skin layer, the release paper transfer method is most preferable from the viewpoint of improving the physical properties of the obtained skin layer. The skin layer and the adhesive used in such a release paper transfer method may be any as long as they can be bonded to the leather material of the present invention, but a polyurethane resin is preferable in terms of texture and physical properties, From the viewpoint of VOC-free and environmental burden, an aqueous or solventless system is desirable.

  The leather material obtained by the present invention can be used in the fields of vehicles, furniture, clothing, shoes, bags, bags, sandals, miscellaneous goods, and the like.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

  In addition, the leather material obtained by each Example and each comparative example was evaluated by the following method.

(1) Migration prevention For the leather material obtained in each of the examples and comparative examples, the cross section of the leather material was observed at a magnification of 60 times using a scanning electron microscope [Scanning Electron Microscope S-2400 (HITACHI)]. Then, the fixed state of the polyurethane resin present in the central portion of the nonwoven fabric was compared with the fixed state of the polyurethane resin present in the surface portion of the nonwoven fabric, and evaluated according to the following criteria.
Grade 5: In the leather material cross section, there is no difference in the amount of resin fixing between the central portion and the surface portion, and no migration occurs.
Fourth grade: In the leather material cross section, there is almost no difference in the resin fixing amount between the central portion and the surface portion, and no migration occurs.
Third grade: In the leather material cross section, a slight difference is observed in the resin fixing amount between the central portion and the surface portion, and no resin fixing is observed in 10% of the central portion in the entire thickness.
Second grade: In the leather material cross section, a considerable difference is observed in the resin fixing amount between the central portion and the surface portion, and no resin fixing is observed in 30% of the central portion in the total thickness.
First grade: In the leather material cross section, there is a marked difference in the amount of resin fixing between the central portion and the surface portion, and no resin fixing is observed in 50% of the central portion of the total thickness.

(2) Abrasion test The leather material obtained in each example and each comparative example was subjected to a soft wheel CS-10 using a Taber abrasion tester [manufactured by Yasuda Seiki Seisakusho] according to the Taber method of JIS L 1096 (1999). The amount of decrease in the weight of the leather material after applying a load of 500 g and being worn 1000 times and 3000 times is shown as the amount of wear. The smaller the amount of wear, the better the wear resistance of the leather material.

(3) Friction fastness For the leather material obtained in each example and each comparative example, a load of 200 g was applied by a Gakushin type friction tester [manufactured by Daiei Chemical Seiki Seisakusho] according to JIS L 0849 (1996). The wet friction fastness was measured by rubbing 100 times. The measurement of the fastness to friction was evaluated according to the following criteria by comparing the degree of contamination of the cotton lacquer using a gray scale for contamination.
5th grade: No contamination was observed.
Grade 4: Slight contamination is observed.
Grade 3: Contamination is clearly recognized.
Second grade: Slightly significant contamination is observed.
First grade: Significant contamination is observed.

(4) Presence / absence of residues Methanol is extracted for the content of components (residues such as surfactants) other than the nonwoven fabric and polyurethane resin in the leather material for the leather material obtained in each Example and each Comparative Example. Measure the extraction amount when extracted at 70 ° C for 3 hours with a Soxhlet extractor as a solvent. If the extraction amount is 1.0 mass% or more, the residue is present. Evaluated as no residue.

(5) Texture According to the following criteria, the texture of the leather material obtained in each Example and each Comparative Example was evaluated in five grades from grade 5 (flexible) to grade 1 (crude).
Grade 5: A texture that is flexible and extremely rich in impact resilience.
Grade 4: A texture that is flexible and rich in impact resilience.
Grade 3: A texture that is flexible but slightly lacks resilience.
Second grade: Slightly hard and paper-like (paper-like) texture.
First grade: Rough and paper-like (paper-like) texture.

[Synthesis Examples and Comparative Synthesis Examples]
Below, the synthesis example of the carboxyl group-containing polyurethane resin used for this invention and the comparative synthesis example of the water-based polyurethane resin used for a comparative example are shown.

(Synthesis Example 1)
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen inlet tube, 157.0 g of 1,6-hexanediol polycarbonate polyol (average molecular weight 2000), 7.5 g of neopentyl glycol, trimethylolpropane 1 .3 g, dimethylolpropionic acid 9.5 g, dibutyltin dilaurate 0.001 part and methyl ethyl ketone 105 g were mixed and mixed uniformly. A methyl ethyl ketone solution of a carboxyl group-containing isocyanate group-terminated prepolymer having an isocyanate group content of 1.9% by mass was obtained.

  After cooling the solution to 50 ° C. or lower, 6.8 g of triethylamine was added, and a neutralization reaction was performed at 40 ° C. for 30 minutes. Next, the neutralized solution is cooled to 30 ° C. or lower, and 421.9 g of water is gradually added using a disperse blade to emulsify and disperse the neutralized product of the carboxyl group-containing isocyanate group-terminated prepolymer. Got. Then, an aqueous polyamine solution in which 5.2 g of 60% by mass of hydrazine hydrate and 1.1 g of diethylenetriamine were dissolved in 20 g of water was added to the dispersion and subjected to chain extension reaction for 60 minutes, and then at 35 ° C. under reduced pressure. Solvent removal, aqueous dispersion of a stable carboxyl group-containing polyurethane resin having a non-volatile content of 35.0% by mass, a viscosity of 120 mPa · s (BM viscometer, No. 2 rotor, 60 rpm), a pH value of 7.8, and an average particle size of 90 nm I got a thing.

  The carboxyl group content in this carboxyl group-containing polyurethane resin was 1.3% by mass, and the value of 100% modulus was 2 MPa. Further, the aqueous dispersion of the carboxyl group-containing polyurethane resin did not gel when heated at 90 ° C., and had no heat-sensitive coagulation property.

(Synthesis Example 2)
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen inlet tube, 178.0 g of 1,6-hexanediol polycarbonate polyol (average molecular weight 2000), 0.9 g of trimethylolpropane, dimethylolpropionic acid 9.3 g, 0.001 part of dibutyltin dilaurate and 105 g of methyl ethyl ketone were added and mixed uniformly. Then, 56.9 g of dicyclohexylmethane diisocyanate was added, reacted at 80 ° C. for 420 minutes, and the content of free isocyanate groups relative to the nonvolatile content A methyl ethyl ketone solution of 1.2% by mass of a carboxyl group-containing isocyanate group-terminated prepolymer was obtained.

  After cooling the solution to 50 ° C. or lower, 6.7 g of triethylamine was added, and a neutralization reaction was performed at 40 ° C. for 30 minutes. Next, the neutralized solution was cooled to 30 ° C. or lower, and 424.4 g of water was gradually added using a disper blade to emulsify and disperse the carboxyl group-containing isocyanate group-terminated prepolymer, thereby obtaining a dispersion. Then, an aqueous polyamine solution in which 3.3 g of 60% by mass of hydrazine hydrate and 0.7 g of diethylenetriamine were dissolved in 20 g of water was added to the dispersion, and a chain extension reaction was performed for 60 minutes, and then at 35 ° C. under reduced pressure. Solvent removal, water dispersion of a stable carboxyl group-containing polyurethane resin having a non-volatile content of 35.0% by mass, a viscosity of 70 mPa · s (BM viscometer, No. 1 rotor, 60 rpm), a pH value of 7.6, and an average particle size of 120 nm I got a thing.

  The carboxyl group content in this carboxyl group-containing polyurethane resin was 1.3% by mass, and the 100% modulus was 5 MPa. Further, the aqueous dispersion of the carboxyl group-containing polyurethane resin did not gel when heated at 90 ° C., and had no heat-sensitive coagulation property.

(Synthesis Example 3)
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen inlet tube, 141.9 g of polytetramethylene glycol (average molecular weight 2000), 30.8 g of dimethylolpropionic acid, 0.001 part of dibutyltin dilaurate And 105 g of methyl ethyl ketone were added and mixed uniformly. Then, 72.3 g of hexamethylene diisocyanate was added and allowed to react at 80 ° C. for 180 minutes. A methyl ethyl ketone solution of the terminal prepolymer was obtained.

  After cooling the solution to 50 ° C. or lower, 22.1 g of triethylamine was added, and a neutralization reaction was performed at 40 ° C. for 30 minutes. Next, the neutralized solution was cooled to 30 ° C. or lower, and 402.6 g of water was gradually added using a disper blade to emulsify and disperse the carboxyl group-containing isocyanate group-terminated prepolymer, thereby obtaining a dispersion. Then, an aqueous polyamine solution prepared by dissolving 8.6 g of 60% by mass of hydrazine hydrate and 1.8 g of diethylenetriamine in 20 g of water was added to the dispersion and subjected to a chain extension reaction for 60 minutes, and then at 35 ° C. under reduced pressure. Solvent removal, aqueous dispersion of a stable carboxyl group-containing polyurethane resin having a non-volatile content of 35.0% by mass, a viscosity of 50 mPa · s (BM viscometer, No. 1 rotor, 60 rpm), a pH value of 7.9 and an average particle size of 150 nm I got a thing.

  The carboxyl group content in this carboxyl group-containing polyurethane resin was 4.2% by mass, and the 100% modulus was 8 MPa. Further, the aqueous dispersion of the carboxyl group-containing polyurethane resin did not gel when heated at 90 ° C., and had no heat-sensitive coagulation property.

(Synthesis Example 4)
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen inlet tube, 157.0 g of 1,6-hexanediol polycarbonate polyol (average molecular weight 2000), 7.5 g of neopentyl glycol, trimethylolpropane 1 .3 g, dimethylolpropionic acid 9.5 g, dibutyltin dilaurate 0.001 part and methyl ethyl ketone 105 g were mixed and mixed uniformly. Then, 69.7 g of isophorone diisocyanate was added, reacted at 80 ° C. for 300 minutes, and released to non-volatile content A methyl ethyl ketone solution of a carboxyl group-containing isocyanate group-terminated prepolymer having an isocyanate group content of 1.9% by mass was obtained.

  After cooling the solution to 50 ° C. or lower, 8.6 g of triethylamine was added, and a neutralization reaction was performed at 40 ° C. for 30 minutes. Next, the neutralized solution was cooled to 30 ° C. or lower, and 420.1 g of water was gradually added using a disper blade to emulsify and disperse the carboxyl group-containing isocyanate group-terminated prepolymer to obtain a dispersion. Then, an aqueous polyamine solution prepared by dissolving 5.2 g of 60% by mass hydrated hydrazine and 1.1 g of diethylenetriamine in 20 g of water was added to the dispersion and subjected to chain extension reaction for 60 minutes, and then degassed at 35 ° C. under reduced pressure. An aqueous dispersion of a stable carboxyl group-containing polyurethane resin having a non-volatile content of 35.0% by mass, a viscosity of 180 mPa · s (BM viscometer, No. 2 rotor, 60 rpm), a pH value of 9.5 and an average particle size of 70 nm. Got.

  The carboxyl group content in this carboxyl group-containing polyurethane resin was 1.3% by mass, and the 100% modulus was 2 MPa. Further, the aqueous dispersion of the carboxyl group-containing polyurethane resin did not gel when heated at 90 ° C., and had no heat-sensitive coagulation property.

(Comparative Synthesis Example 1)
In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen inlet tube, 76.1 g of polytetramethylene glycol (average molecular weight 1000), polyoxyethylene polypropylene glycol random copolymer glycol (average molecular weight 1000, Oxyethylene group-containing 70% by mass) 16.9 g, 1.5 g of 1,4-butanediol, 1.9 g of trimethylolpropane, 0.001 g of dibutyltin dilaurate and 60 g of methyl ethyl ketone were mixed and mixed uniformly, and then dicyclohexylmethane diisocyanate. 40.4 g was added and reacted at 80 ° C. for 300 minutes to obtain a methyl ethyl ketone solution of an isocyanate group-terminated prepolymer having a free isocyanate group content of 2.1% by mass relative to the nonvolatile content.

  After cooling the solution to 30 ° C. or lower, 0.1 g of decyl phosphate ester and 6.0 g of polyoxyethylene tristyryl phenyl ether (HLB = 15) were added and mixed uniformly, and then water 254 was added using a disper blade. 0.0 g was gradually added to perform phase inversion emulsification and dispersion to obtain a dispersion. Then, an aqueous polyamine solution in which 2.0 g of piperazine hexahydrate and 0.8 g of diethylenetriamine are dissolved in 11.3 g of water is added to the dispersion and subjected to a chain extension reaction for 90 minutes, and then at 35 ° C. under reduced pressure. Solvent removal, water dispersion of stable aqueous polyurethane resin having non-volatile content of 35.0 mass%, viscosity of 50.0 mPa · s (BM viscometer No. 1 rotor, 60 rpm), pH value of 8.0 and average particle size of 550 nm Got.

  The content of carboxyl groups in this aqueous polyurethane resin was 0.0% by mass, and the 100% modulus was 2 MPa. The aqueous dispersion of the aqueous polyurethane resin was gelled at 45 ° C. and had heat-sensitive coagulation properties.

  Hereinafter, Table 1 summarizes the properties of Synthesis Examples 1 to 4 and Comparative Synthesis Example 1.

[Examples 1-6 and Comparative Examples 1-5]
Example 1
100 g of an aqueous dispersion of a carboxyl group-containing polyurethane resin obtained in Synthesis Example 1, 17.5 g of a 10% by weight aqueous solution of ammonia formate (pH value 7.3), Textport BG [alcohol penetrant, trade name, Nika Chemical A mixed solution was prepared by uniformly mixing 6.0 g of a 50% by mass aqueous solution and 16.5 g of water. The mixture ratio of the carboxyl group-containing polyurethane resin and ammonia formate in the mixed solution was 100: 5, the pH value was 7.9, the thermal coagulation temperature was 45 ° C., and the carboxyl group-containing polyurethane resin amount was 25% by mass.

This mixed solution was impregnated into a non-woven fabric (0.5 dtex, density 0.3 g / cm ³ ) made of polyester fiber using a slit mangle so as to be 250% by mass of a pickup, and then a hot air dryer [TABAI SAFETYOVEN SPH-200] was dried at 100 ° C. for 3 minutes and then at 150 ° C. for 3 minutes to obtain artificial leather. Furthermore, the obtained artificial leather (leather material) was dyed under the following conditions and subjected to RC soaping to obtain an artificial leather dyed cloth (dyed leather material).

Dyeing conditions <br/> Dyeing machine: Mini color dyeing machine [Texam Giken Co., Ltd.]
Dye: Kayalon Microester Blue DX-LS conc [Nippon Kayaku Co., Ltd.] 0.10% owf
Kayalon Maicroester Yellow DX-LS [Nippon Kayaku Co., Ltd.] 2.00% owf
Kayalon Maicroester Red DX-LS [Nippon Kayaku Co., Ltd.] 0.80% owf
Dyeing assistant: Nikka Sun Salt RM-340 [Nikka Chemical Co., Ltd.] 0.5 g / L
pH adjuster: 90% mass acetic acid 0.3cc / L
Bath ratio: (1:20)
Dyeing conditions: 130 ° C. × 60 minutes (heating rate 2 ° C./min).

RC condition RC bath: Sodium hydroxide 2g / L
Hydrosulfite 2g / L
Bath ratio: (1:20)
RC condition: 80 ° C. × 20 minutes (temperature increase rate 2 ° C./min).

(Example 2)
100 g of an aqueous dispersion of the carboxyl group-containing polyurethane resin obtained in Synthesis Example 1, 26.3 g of a 20% by weight aqueous solution of ammonia formate (pH value 7.3), Textport BG [alcohol penetrant, trade name, Nikka Chemical A mixed solution was prepared by uniformly mixing 6.0 g of a 50% by mass aqueous solution and 7.7 g of water. The mixture ratio of the carboxyl group-containing polyurethane resin and ammonia formate in the mixed solution was 100: 15, the pH value was 7.6, the thermal coagulation temperature was 45 ° C., and the carboxyl group-containing polyurethane resin amount was 25% by mass.

  An artificial leather dyed cloth (dyed leather material) was obtained in the same manner as in Example 1 except that such a mixed solution was used.

(Example 3)
100 g of an aqueous dispersion of the carboxyl group-containing polyurethane resin obtained in Synthesis Example 2, 17.5 g of a 10% by weight aqueous solution of ammonia formate (pH value 7.3), Textport BG [alcohol penetrant, trade name, Nikka Chemical A mixed solution was prepared by uniformly mixing 6.0 g of a 50% by mass aqueous solution and 16.5 g of water. The mixture ratio of the carboxyl group-containing polyurethane resin and ammonia formate in this mixed solution was 100: 5, the pH value was 7.7, the thermal coagulation temperature was 46 ° C., and the amount of the carboxyl group-containing polyurethane resin was 25% by mass.

  An artificial leather dyed cloth (dyed leather material) was obtained in the same manner as in Example 1 except that such a mixed solution was used.

Example 4
100 g of an aqueous dispersion of a carboxyl group-containing polyurethane resin obtained in Synthesis Example 3, 17.5 g of a 10% by weight aqueous solution of ammonia formate (pH value 7.3), Textport BG [alcohol penetrant, trade name, Nikka Chemical A mixed solution was prepared by uniformly mixing 6.0 g of a 50% by mass aqueous solution and 16.5 g of water. The mixture ratio of the carboxyl group-containing polyurethane resin and ammonia formate in the mixed solution was 100: 5, the pH value was 7.7, the thermal coagulation temperature was 51 ° C., and the carboxyl group-containing polyurethane resin amount was 25% by mass.

  An artificial leather dyed cloth (dyed leather material) was obtained in the same manner as in Example 1 except that such a mixed solution was used.

(Example 5)
100 g of an aqueous dispersion of a carboxyl group-containing polyurethane resin obtained in Synthesis Example 4, 17.5 g of a 10% by weight aqueous solution of ammonia formate (pH value 7.3), Textport BG [alcohol penetrant, trade name, Nikka Chemical A mixed solution was prepared by uniformly mixing 6.0 g of a 50% by mass aqueous solution and 16.5 g of water. The mixture ratio of the carboxyl group-containing polyurethane resin and ammonia formate in the mixed solution was 100: 5, the pH value was 9.3, the thermal coagulation temperature was 70 ° C., and the carboxyl group-containing polyurethane resin amount was 25% by mass.

  An artificial leather dyed cloth (dyed leather material) was obtained in the same manner as in Example 1 except that such a mixed solution was used.

(Example 6)
100 g of an aqueous dispersion of the carboxyl group-containing polyurethane resin obtained in Synthesis Example 1, 17.5 g of a 10% by weight aqueous solution of ammonia stearate (pH value 8.1), Carbodilite E-02 [carbodiimide-based crosslinking agent, trade name, Nisshinbo Co., Ltd.] 1.0 g, Textport BG [alcohol penetrant, trade name, manufactured by Nikka Chemical Co., Ltd.] 50% by weight aqueous solution 6.0 g and water 16.5 g were mixed evenly and mixed. Was prepared. The mixture ratio of the carboxyl group-containing polyurethane resin and ammonia stearate in the mixed solution was 100: 5, the pH value was 7.7, the thermal coagulation temperature was 46 ° C., and the carboxyl group-containing polyurethane resin amount was 25% by mass. .

  An artificial leather dyed cloth (dyed leather material) was obtained in the same manner as in Example 1 except that such a mixed solution was used.

(Comparative Example 1)
100 g of an aqueous dispersion of the carboxyl group-containing polyurethane resin obtained in Synthesis Example 1, 6.0 g of 50% by weight aqueous solution of Textport BG [alcohol penetrant, trade name, manufactured by Nikka Chemical Co., Ltd.] and 34.0 g of water. Were mixed uniformly to prepare a mixed solution. The mixture ratio of the carboxyl group-containing polyurethane resin and ammonia formate in the mixed solution is 100: 0, the pH value is 7.8, the thermal coagulation temperature is 90 ° C. or more, and the carboxyl group-containing polyurethane resin amount is 25% by mass. there were.

  An artificial leather dyed cloth (dyed leather material) was obtained in the same manner as in Example 1 except that such a mixed solution was used.

(Comparative Example 2)
100 g of an aqueous dispersion of a carboxyl group-containing polyurethane resin obtained in Synthesis Example 1, 17.5 g of a 10% by weight aqueous solution of formic acid (pH 3.0), Textport BG [alcohol penetrant, trade name, Nikka Chemical Co., Ltd. A mixed solution was prepared by uniformly mixing 6.0 g of a 50% by mass aqueous solution and 16.5 g of water. The mixture ratio of the carboxyl group-containing polyurethane resin and formic acid in the mixed solution was 100: 5, the pH value was 6.0, the thermal coagulation temperature was 10 ° C. or less, and the carboxyl group-containing polyurethane resin amount was 25% by mass.

  In addition, since the said liquid mixture added the 10 mass% aqueous solution of formic acid, the deposit was instantaneously seen from the liquid mixture, production of the artificial leather dyed cloth was abandoned.

(Comparative Example 3)
100 g of an aqueous dispersion of the aqueous polyurethane resin obtained in Comparative Synthesis Example 1, 6.0 g of 50 mass% aqueous solution of Textport BG [alcohol penetrant, trade name, manufactured by Nikka Chemical Co., Ltd.] and 34.0 g of water A mixed solution was prepared by mixing uniformly. The mixture ratio of the polyurethane resin and ammonia formate in the mixed solution was 100: 0, the pH value was 8.2, the thermal coagulation temperature was 45 ° C., and the amount of polyurethane resin was 25% by mass.

  An artificial leather dyed cloth (dyed leather material) was obtained in the same manner as in Example 1 except that such a mixed solution was used.

(Comparative Example 4)
100 g of aqueous dispersion of aqueous polyurethane resin obtained in Comparative Synthesis Example 1, 17.5 g of 10% by weight aqueous solution of ammonium formate (pH 7.0), Texport BG [alcohol penetrant, trade name, Nikka Chemical Co., Ltd. A mixed solution was prepared by uniformly mixing 6.0 g of a 50% by mass aqueous solution and 16.5 g of water. The mixture ratio of the polyurethane resin and ammonium formate in the mixed solution was 100: 5, the pH value was 8.1, the thermal coagulation temperature was 45 ° C., and the amount of polyurethane resin was 25% by mass.

  An artificial leather dyed cloth (dyed leather material) was obtained in the same manner as in Example 1 except that such a mixed solution was used.

(Comparative Example 5)
100 g of aqueous dispersion of aqueous polyurethane resin obtained in Comparative Synthesis Example 1, 17.5 g of 10% by weight aqueous solution of calcium chloride (pH 7.0), Textport BG [alcohol penetrant, trade name, Nikka Chemical Co., Ltd. The mixed solution was prepared by uniformly mixing 6.0 g of a 50% by mass aqueous solution and 16.5 g of water. The mixing ratio of the polyurethane resin and calcium chloride in this mixed solution was 100: 5, the pH value was 8.1, the thermal coagulation temperature was 35 ° C., and the amount of polyurethane resin was 25% by mass.

  An artificial leather dyed cloth (dyed leather material) was obtained in the same manner as in Example 1 except that such a mixed solution was used.

  The evaluation results of the artificial leather dyed fabrics (dyed leather materials) obtained in Examples 1 to 6 and Comparative Examples 1 to 5 are shown in Table 2 below.

  In the leather materials obtained in Examples 1 to 6, no migration was observed, and the resin was uniformly fixed to the inside of the nonwoven fabric. By preventing migration in this way, it is confirmed that the texture is very flexible, and it is possible to obtain a leather material exhibiting excellent wear resistance with almost no change in wear amount at 1000 times and 3000 times in the wear resistance test. It was done. Moreover, in the leather materials obtained in Examples 1 to 6, it was confirmed that the residue remaining in the leather material was extremely small, and it was found that the residue has little influence on the friction fastness.

  On the other hand, in the leather material obtained in Comparative Example 1 using only the carboxyl group-containing polyurethane resin and not containing an ammonium salt of carboxylic acid, significant migration was observed during drying and the texture was rough. Furthermore, in the abrasion resistance test of the leather material obtained in Comparative Example 1, the abrasion resistance was good when it was worn 1000 times, but a significant amount of wear was seen when it was worn 3000 times. It was confirmed that the wearability was insufficient.

  In Comparative Example 2, a formic acid aqueous solution was used in place of the carboxylic acid ammonium salt, but the mixed solution was gelled, so that it was not possible to produce a leather material, and it was confirmed that the processability was insufficient. It was done.

  Further, in the leather material obtained in Comparative Example 3 using only the heat-sensitive coagulable aqueous polyurethane resin obtained by emulsification with a surfactant without using an ammonium salt of carboxylic acid, Although it had, significant migration was observed during drying. Further, the leather material obtained in Comparative Example 3 has a rough texture, and in the abrasion resistance test, the abrasion resistance is good when worn 1000 times, but when worn 3000 times. A significant amount of wear was observed, and it was confirmed that the wear resistance was insufficient.

  Furthermore, in the leather material obtained in Comparative Example 4 using an aqueous polyurethane resin having heat-sensitive coagulation property obtained by emulsification with a surfactant and an ammonium salt of carboxylic acid, the leather obtained in Comparative Example 3 was used. Results similar to those for materials were confirmed, and it was confirmed that effects such as migration prevention by ammonium salts of carboxylic acids could not be obtained for aqueous polyurethane resins with heat-sensitive coagulation properties obtained by emulsification with surfactants. It was done.

  The leather obtained in Comparative Example 5 using a mixed solution mixed with an aqueous polyurethane resin obtained by emulsifying with a surfactant using an inorganic salt aqueous solution made of calcium chloride instead of the ammonium salt of carboxylic acid. In the material, the thermal coagulation temperature was lowered by the inorganic salt aqueous solution, and the migration prevention property was slightly improved, but the migration prevention property was insufficient when compared with the leather material obtained in Examples 1-6. . Further, the leather material obtained in Comparative Example 5 has a rough texture, and in the abrasion resistance test, when it is worn 1000 times, the wear resistance is good, but when it is worn 3000 times. A remarkable amount of wear was observed, and it was confirmed that the wear resistance was insufficient. In addition, it was confirmed that the surfactant and inorganic salt remained in the leather material, and it was confirmed that the residue had a great influence on the fastness to friction.

  As described above, according to the present invention, it is possible to sufficiently prevent migration in spite of the manufacturing method of the leather material using the water-based polyurethane resin in consideration of the environmental load and VOC problem, A method for producing a leather material that is capable of efficiently and reliably obtaining a leather material having a soft texture and excellent physical properties such as wear resistance and friction fastness, and a leather material obtained by the production method Can be provided.

  Therefore, the production method of the present invention is particularly useful as an industrial production method for leather materials, and the leather material obtained by the production method of the present invention has no organic solvent remaining in the leather materials. Since the adverse effects on the human body such as skin disorders have been eliminated, it can be used as it is in the industrial fields such as vehicles, furniture, clothing, bags, shoes, bags, sundries, etc. It can also be used as a leather material with excellent quality.

Claims (7)

(A) Carboxyl group-containing polyurethane resin, (B) C1-C18 ammonium salt of carboxylic acid and (C) A liquid mixture containing water is impregnated and dried to obtain a leather material. A method for producing a leather material characterized by the above.   In the mixed solution, the blending ratio of (A) carboxyl group-containing polyurethane resin and (B) ammonium salt of carboxylic acid is (A) :( B) = 100: 0.1-100: The method for producing a leather material according to claim 1, wherein the leather material is 20.   (A) Carboxyl group-containing polyurethane resin obtained by reacting a carboxyl group-containing polyurethane resin with (a) an organic diisocyanate, (b) a polyol, and (c) a compound having a carboxyl group and two or more active hydrogens. A carboxyl group-containing polyurethane resin obtained by neutralizing a polymer and emulsifying and dispersing in water by self-emulsification, and then (d) chain-extending reaction using a polyamine compound having two or more amino groups and / or imino groups. The method for producing a leather material according to claim 1 or 2, wherein   (A) Content of the carboxyl group in a carboxyl group-containing polyurethane resin is 0.5-4.0 mass%, The leather material as described in any one of Claims 1-3 characterized by the above-mentioned. Manufacturing method.   (A) The method for producing a leather material according to any one of claims 1 to 4, wherein a value of 100% modulus of the carboxyl group-containing polyurethane resin is 1 to 9 MPa.   (B) Carboxylic acid in the ammonium salt of carboxylic acid is C1-C10 carboxylic acid, The manufacturing method of the leather material as described in any one of Claims 1-5 characterized by the above-mentioned. The pH value of the said liquid mixture is 7.0-9.0, and solidification temperature is 30-70 degreeC, The manufacturing method of the leather material as described in any one of Claims 1-6 characterized by the above-mentioned. .