TW201925280A - Method for producing coagulated article - Google Patents

Abstract

The present invention provides a method for producing a coagulated article, the method being characterized in that a urethane resin composition containing water is coagulated using the salt of an acid having two or more carboxyl groups. The coagulation preferably is carried out at a temperature of less than 40 DEG C. The salt of the acid having two or more carboxyl groups preferably is a citrate and/or a tartrate. The urethane resin composition preferably contains a urethane resin having an anionic group. The method for producing the coagulated article preferably has a step for impregnating an aqueous urethane resin composition with a fibrous base material and then immersing the same in the salt of an acid having two or more carboxyl groups. According to this production method, it is possible to obtain exceptional coagulation properties such that contamination of a coagulation bath by the urethane resin does not occur and debris of the urethane resin is not produced when the coagulated article is squeezed.

Description

 Method for producing coagulum  

The present invention relates to a method of producing a coagulum which can be used, for example, in the production of leather swatches and the like.

Compared with the conventional organic solvent-based urethane resin composition, the urethane resin composition in which the urethane resin is dispersed in water can reduce the burden on the environment, and thus it is used as a leather sample such as artificial leather or synthetic leather. In recent years, it has been suitably used as a manufacturing material such as a leather piece such as artificial leather or synthetic leather, a coating agent, or an adhesive.

The leather sample sheet is generally composed of a fibrous base material such as a non-woven fabric, an intermediate layer including a porous layer or the like, and a skin layer as required, and the fiber base material is improved in bending resistance and texture of the leather sample sheet. For the purpose, a fibrous base material such as a nonwoven fabric is impregnated with a water-based urethane resin composition and a thermosensitive coagulant (impregnated layer) is used.

The aqueous urethane resin composition for impregnation of the fibrous base material includes, for example, a urethane resin containing a carboxyl group and/or a sulfonic acid group, and a polyfunctional quaternary ammonium salt as a heat-sensitive coagulant. And a water-based urethane resin composition (see, for example, Patent Document 1).

However, it has been pointed out that the urethane resin composition solidified by heat-sensitization is solidified because the urethane resin blending liquid is once low-viscosity by heating, and the resin is easily pulverized by capillary action. Adhered to the fiber interlacing point, and the resin converges on the fiber, the formed film is poor in flexibility, and the residue of the urethane resin is generated when the solidified fiber substrate is twisted.

Prior technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open No. 2015-7172

An object of the present invention is to provide a production method which does not cause contamination by a urethane resin in a coagulation bath and which is excellent in coagulability.

The present invention provides a method for producing a coagulum, which is characterized in that a hydrous urethane resin composition is solidified by a salt of an acid having two or more carboxyl groups.

According to the production method of the present invention, contamination by the urethane resin does not occur in the coagulation bath, and excellent coagulability of the residue of the urethane resin which does not occur when the coagulum is squeezed can be obtained. Further, when the urethane resin is solidified in the fiber base material, since excellent texture, flexibility, and abrasion resistance can be obtained, it can be suitably used for the production of gloves, paints, leather samples, and the like.

Best embodiment of the invention

The method for producing a coagulum of the present invention is characterized in that a water-containing urethane resin composition is solidified by a salt of an acid of two or more valences.

In the present invention, it is necessary to use a salt of an acid having two or more carboxyl groups as a coagulant to carry out salt solidification. This specific coagulant does not contaminate solidification because it has a high salting ability compared to a coagulant such as sodium chloride or calcium nitrate which has been widely used in the solidification of a salt of an aqueous urethane resin composition. The bath has excellent coagulability which does not require high temperature such as heat-sensitization (preferably at a temperature lower than 40 ° C, more preferably at 20 to 35 ° C).

For the above acid having two or more carboxyl groups, for example, succinic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, pimelic acid, octyl can be used. Diacid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tartaric acid, citric acid, aconitic acid, glutamic acid, aspartic acid, and the like. These acids may be used singly or in combination of two or more. Among these, citric acid and/or tartaric acid is preferably used because of its superior salting ability.

As the salt forming the above acid, for example, sodium, potassium, rubidium, calcium, magnesium, zinc, aluminum or the like can be used. These may be used alone or in combination of two or more.

Specific examples of the method for producing a coagulum of the present invention include, for example, impregnating a fibrous substrate with an aqueous urethane resin composition, and then immersing the impregnated substrate in an acid having two or more carboxyl groups. a method of producing a coagulum of an urethane resin in a coagulation bath of a salt; immersing the fiber substrate in a coagulation bath of a salt having an acid of two or more carboxyl groups, and then further immersing the substrate in water In the urethane resin composition, a method of producing a coagulum of an urethane resin or the like is used. Among these, when the former method is used, since the coagulum of the urethane resin is filled into the inside of the fiber base material, the coagulum is wound around the fiber base material, so that it can be suitably used as the leather. The impregnation layer of the sample. Further, in the case of using the latter method, since the urethane coagulum layer is formed on the surface of the fiber substrate and in the vicinity of the surface, it can be suitably used in the production of gloves. Further, after the impregnation layer of the leather piece is manufactured by the above method, a skin layer or a top coat layer may be further provided thereon by a conventional method to obtain a leather sample piece.

The concentration of the salt having the acid of the above two or more carboxyl groups in the coagulation bath is preferably in the range of 10 to 80% by mass, more preferably 15 to 5, from the viewpoint of obtaining more excellent coagulability. 50% by mass range.

As the fiber base material, for example, a nonwoven fabric, a woven fabric, a woven fabric, or the like can be used. For the fiber substrate, for example, polyester fiber, nylon fiber, acrylic fiber, polyurethane fiber, acetate fiber, snail fiber, polylactic acid fiber, cotton, hemp, silk, Wool, blended fibers, etc.

In the method of impregnating the above fibrous substrate with the aqueous urethane resin composition, for example, the fibrous substrate is placed in a tank in which the aqueous urethane resin composition is stored, and then A method of screwing the excess with a rolling press or the like. The above impregnation time is, for example, in the range of 1 to 30 minutes.

Then, the substrate is taken out and further immersed in a coagulation bath in which the salt of the acid having two or more carboxyl groups is stored, whereby the urethane resin in the urethane resin composition is solidified, and the obtained product can be obtained. A fibrous base material in which the coagulum adheres to the surface and inside of the fibrous base material. In the case of the immersion and solidification time at this time, for example, it is in the range of 1 to 30 minutes. Further, the coagulation bath at the time of immersion is preferably less than 40 ° C, more preferably 20 to 35 ° C from the viewpoint of balance between coagulability and texture and abrasion resistance.

The fibrous base material having the coagulum of the urethane resin may be immersed in running water for, for example, 10 minutes to 2 hours after the immersion and solidification as necessary, and the unnecessary coagulant may be removed by washing.

Further, in the method of immersing the fiber base material in a coagulation bath in which the acid having two or more carboxyl groups is stored, for example, the fiber base material is directly immersed in a coagulation bath in which the alcohol solvent is stored. The method in . The above immersion time is, for example, in the range of 5 seconds to 10 minutes.

Next, the substrate is taken out and further immersed in the aqueous urethane resin composition, whereby the urethane resin in the urethane resin composition is solidified to obtain a fibrous substrate. A fibrous base material having an ethyl carbamate coagulum layer formed on the surface layer and the vicinity of the surface layer. In the case of the immersion and solidification time at this time, for example, it is in the range of 1 to 30 minutes. Further, the coagulation bath at the time of immersion may be normal temperature, but may be heated to, for example, 30 to 70 °C.

The fibrous base material having the coagulum of the urethane resin may be immersed in running water after the above-mentioned immersion and solidification, for example, for 10 minutes to 2 hours, and washed to remove unnecessary coagulant.

For the aqueous urethane resin composition which can be used in the present invention, for example, those containing the urethane resin (A) and the aqueous medium (B) can be used.

The urethane resin (A) may be dispersed in the aqueous medium (B) described below, and for example, an urethane resin having a hydrophilic group such as an anionic group, a cationic group or a nonionic group may be used; The urethane resin or the like which is forcibly dispersed in the aqueous medium (B) with an emulsifier. These urethane resins (A) may be used singly or in combination of two or more. Among these, from the viewpoint of production stability, it is preferred to use an aqueous urethane resin having a hydrophilic group, from the viewpoint that the coagulating agent used in the present invention is easily solidified, and a polyurethane resin. From the viewpoint of being easily filled and wound inside the fibrous substrate and having a higher texture, it is more preferable to use an urethane resin having an anionic group.

In the method of obtaining the urethane resin having an anionic group, for example, one or more compounds selected from the group consisting of a compound having a carboxyl group and a compound having a sulfonyl group are used as a raw material. Methods.

For the above compound having a carboxyl group, for example, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylol-butyric acid, 2,2-di can be used. Hydroxymethyl valeric acid and the like. These compounds may be used singly or in combination of two or more.

For the above compound having a sulfonyl group, for example, 3,4-diaminobutanesulfonic acid, 3,6-diamino-2-toluenesulfonic acid, 2,6-diaminobenzenesulfonate can be used. Acid, N-(2-aminoethyl)-2-aminoethylsulfonic acid, and the like. These compounds may be used singly or in combination of two or more.

The carboxyl group and the sulfonyl group may be partially or completely neutralized with a basic compound in the urethane resin composition. As the above basic compound, for example, a group amine such as ammonia, triethylamine, pyridine or ifolin; an alkanolamine such as monoethanolamine or dimethylethanolamine; and sodium, potassium, lithium, calcium, etc. may be used. a metal base compound or the like.

In the method of obtaining the urethane resin having a cationic group, for example, one or two or more kinds of compounds having an amine group are used as a raw material.

As the compound having an amine group, for example, a compound having a primary or secondary amine group such as triethylenetetramine or diethylenetriamine; N-methyldiethanolamine, N-ethyldiethanolamine or the like can be used. - an alkyl dialkanolamine; a compound having a tertiary amino group such as N-alkyldiaminoalkylamine such as N-methyldiaminoethylamine or N-ethyldiaminoethylamine; and the like. These compounds may be used singly or in combination of two or more.

In the method of obtaining the above-mentioned urethane resin having a nonionic group, for example, one or two or more kinds of compounds having an oxyethyl group structure are used as a raw material.

With respect to the above compound having an oxyethylidene structure, for example, polyoxyethylene ethylene glycol, polyoxyethylene methyl polyoxypropyl propylene glycol, polyoxyethylene ethylene polyoxytetramethylene glycol, or the like can be used. A polyether polyol having an oxygen-extended ethyl structure. These compounds may be used singly or in combination of two or more.

For the emulsifier used in the above-mentioned urethane resin which is forcibly dispersed in the aqueous medium (B), for example, polyoxyethylidene phenyl ether, polyoxyethylene ethyl laurel can be used. Nonionic emulsifier such as ether, polyoxyethylidene phenyl ether, polyoxyethylene ethyl sorbitol tetraoleate, polyoxyethylene ethyl/polyoxypropyl propylene copolymer; sodium oleate Equal fatty acid salt, alkyl sulfate salt, alkyl benzene sulfonate, alkyl sulfosuccinate, naphthalene sulfonate, polyoxyethylidene sulfate, sodium sulfonate, alkyl An anionic emulsifier such as a sodium salt of phenyl ether sulfonate; a cationic emulsifier such as an alkylamine salt, an alkyltrimethylammonium salt or an alkyldimethylbenzylammonium salt. These emulsifiers may be used singly or in combination of two or more.

In the above urethane resin (A), specifically, a polyisocyanate (a1), a polyhydric alcohol (a2), a raw material for producing the above-described hydrophilic group-containing urethane resin, and The chain extender (a3) is obtained as a raw material in response to the need. These reactions can be carried out using a conventional urethane reaction.

As the above polyisocyanate (a1), for example, phenylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, benzoyl diisocyanate, naphthalene diisocyanate, polymethylene polyphenyl poly can be used. Aromatic polyisocyanates such as isocyanate or carbodiimidized diphenylmethane polyisocyanate; hexamethylene diisocyanate, diazonium diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate An aliphatic or alicyclic polyisocyanate such as benzoyl diisocyanate, tetramethyl benzoyl diisocyanate, dimer acid diisocyanate or decene diisocyanate. These polyisocyanates may be used singly or in combination of two or more.

As the above polyol (a2), for example, a polyether polyol, a polyester polyol, a polyacryl polyol, a polycarbonate polyol, a polybutadiene polyol, or the like can be used. These polyols may be used singly or in combination of two or more.

The number average molecular weight of the above polyol (a2) is preferably in the range of 500 to 10,000, more preferably in the range of 800 to 5,000, from the viewpoint of mechanical strength of the obtained film. Further, the number average molecular weight of the above polyol (a2) is a value measured by a gel permeation chromatography (GPC) method.

As the chain extender (a3), for example, ethylenediamine, 1,2-propylenediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, Isophorone diamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4'-dicyclohexylmethanediamine, 3,3'- a chain extender having an amine group such as dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine or hydrazine; ethylene glycol, diethylene glycol, triethylene glycol, Propylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, sucrose, methylene glycol, glycerin, sorbitol, bisphenol A, A chain extender having a hydroxyl group such as 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether or trimethylolpropane. These chain extenders may be used singly or in combination of two or more.

The polyisocyanate (a1), the above polyol (a2), and the chain extender (a3) are preferably used from the viewpoint of further improving the durability of the film in terms of the amount of the chain extender (a3). The range of 0.5 to 20% by mass, more preferably 1 to 10% by mass, is more preferably in the total mass.

In addition, when the urethane resin having an aromatic ring obtained by using an aromatic polyisocyanate as a raw material is used as the urethane resin (A), from the viewpoint of obtaining more excellent coagulability and texture, Preferably, the content of the aromatic ring is in the range of 0.8 to 8 mol/kg, more preferably 1 to 6 mol/kg, in the urethane resin.

The method for producing the urethane resin (A) may, for example, produce a urethane prepolymer having an isocyanate group by reacting the polyisocyanate (a1) with the polyol (a2). And then, if necessary, a method of reacting the above-mentioned urethane prepolymer with the chain extender (a3); and the above polyisocyanate (a1), the above polyol (a2), and the like The chain extender (a3) is a method of feeding and reacting at a time. These reactions can be, for example, carried out at 50 to 100 ° C for 3 to 10 hours.

When the urethane resin (A) is produced, it is preferred to inactivate the isocyanate group remaining in the urethane resin (A), and when the isocyanate group is deactivated, it is preferred to use methanol or the like. An alcohol having one hydroxyl group. The amount of the alcohol to be used is preferably in the range of 0.001 to 10 parts by mass based on 100 parts by mass of the urethane resin (A).

Further, in the production of the above urethane resin (A), an organic solvent may also be used. For the above organic solvent, for example, a ketone compound such as acetone or methyl ethyl ketone; an ether compound such as tetrahydrofuran or dioxane; an acetate compound such as ethyl acetate or butyl acetate; or a nitrile compound such as acetonitrile; A guanamine compound such as methylformamide or N-methylpyrrolidone. These organic solvents may be used singly or in combination of two or more. Further, when the organic solvent is obtained from the urethane resin composition, it is preferably removed by distillation or the like.

As the aqueous medium (B), for example, water, an organic solvent which is mixed with water, a mixture of these, or the like can be used. As the organic solvent to be mixed with water, for example, an alcohol solvent such as methanol, ethanol, or isopropanol; a ketone solvent such as acetone or methyl ethyl ketone; ethylene glycol, diethylene glycol or propylene glycol can be used. A polyalkylene glycol solvent; an alkyl ether solvent of a polyalkylene glycol; an indoleamine solvent such as N-methyl-2-pyrrolidone; These aqueous media may be used singly or in combination of two or more. Among these, it is more preferable to use only water from the viewpoint of safety and environmental load reduction.

The mass ratio [(A)/(B)] of the above urethane resin (A) to the above aqueous medium (B) is preferably in the range of 10/80 to 70/30 from the viewpoint of workability. More preferably, it is in the range of 20/80~60/40.

The urethane resin composition used in the present invention may contain other additives as needed in addition to the urethane resin (A) and the aqueous medium (B).

For the above other additives, for example, an emulsifier, a neutralizing agent, a thickener, a crosslinking agent, an urethane conversion catalyst, a decane coupling agent, a filler, a thixotropic agent, a tackifier, and a wax can be used. , heat stabilizer, light stabilizer, fluorescent whitening agent, foaming agent, pigment, dye, conductive imparting agent, antistatic agent, moisture permeability promoter, water repellent, oil-repellent agent, hollow foam, Flame retardant, water absorbing agent, moisture absorbent, deodorant, foam stabilizer, anti-caking agent, hydrolysis inhibitor, and the like. These additives may be used singly or in combination of two or more.

When the anionic aqueous urethane resin is used as the aqueous urethane resin (A), the neutralizing agent neutralizes the carboxyl group, and for example, sodium hydroxide or potassium hydroxide can be used. A non-volatile base; a tertiary amine compound such as trimethylamine, triethylamine, dimethylethanolamine, methyldiethanolamine or triethanolamine. These neutralizing agents may be used singly or in combination of two or more.

The amount of the carboxyl group contained in the urethane resin (A) is preferably in the range of 0.8 to 1.2 times the amount of the carboxyl group contained in the urethane resin (A).

As described above, according to the production method of the present invention, contamination by the urethane resin does not occur in the coagulation bath, and excellent solidification of the residue of the urethane resin which does not occur when the coagulum is squeezed can be obtained. Sex. Further, when the urethane resin is solidified in the fiber base material, since excellent texture, flexibility, and abrasion resistance can be obtained, it can be suitably used for production of gloves, paints, and leather plaques.

Example

Hereinafter, the present invention will be described in further detail using examples.

 [Synthesis Example 1] Modification of urethane resin composition (X-1)  

In the presence of 3,281 parts by mass of methyl ethyl ketone and 0.1 parts by mass of stannous octoate, a polycarbonate polyol (Nipporane 980R, manufactured by Japan Polyurethanes Co., Ltd., number average molecular weight: 2,000) was 1,000 at 1,000 ° C. The mass fraction, 17 parts by mass of 2,2-dimethylolpropionic acid, 47 parts by mass of ethylene glycol and 344 parts by mass of diphenylmethane diisocyanate are reacted until the solution viscosity reaches 20,000 mPa. After s, 3 parts by mass of methanol was added to stop the reaction, and a methyl ethyl ketone solution of the urethane resin (A-1) was obtained. In this urethane resin solution, polyoxyl-Lipophile Balance (hereinafter referred to as "HLB"); 14) 70 parts by mass, 13 parts by mass of triethylamine After the mixing, 800 parts by mass of ion-exchanged water was added to carry out phase inversion emulsification, whereby an emulsion in which the urethane resin (A-1) was dispersed in water was obtained.

Then, methyl ethyl ketone was distilled off from the emulsion, whereby an urethane resin composition (X-1) having a nonvolatile content of 40% by mass was obtained. Further, the content of the aromatic ring in the above urethane resin (A-1) was 1.93 mol/kg.

 [Synthesis Example 2] Preparation of urethane resin composition (X-2)  

Polyether polyol ("PTMG2000" manufactured by Mitsubishi Chemical Co., Ltd., number average molecular weight: 2,000) 1,000 mass at 70 ° C in the presence of 3,281 parts by mass of methyl ethyl ketone and 0.1 parts by mass of stannous octoate Part, 2,2-dimethylolpropionic acid 17 parts by mass, ethylene glycol 47 parts by mass and diphenylmethane diisocyanate 344 parts by mass to a solution viscosity of 20,000 mPa. After s, 3 parts by mass of methanol was added to stop the reaction, and a methyl ethyl ketone solution of the urethane resin (A-2) was obtained. In this urethane resin solution, polyoxyl-Lipophile Balance (hereinafter referred to as "HLB"); 14) 70 parts by mass, 13 parts by mass of triethylamine After the mixing, 800 parts by mass of ion-exchanged water was added to carry out phase inversion emulsification, whereby an emulsion in which the urethane resin (A-2) was dispersed in water was obtained.

Then, methyl ethyl ketone was distilled off from the emulsion, whereby an urethane resin composition (X-2) having a nonvolatile content of 40% by mass was obtained. Further, the content of the aromatic ring in the above urethane resin (A-2) was 1.93 mol/kg.

 [Synthesis Example 3] Preparation of aqueous urethane resin composition (X-3)  

Polyester polyol ("Placcel 220" manufactured by Daicel Co., Ltd.; number average molecular weight: 2,000) 1,000 parts by mass at 70 ° C in the presence of 3,281 parts by mass of methyl ethyl ketone and 0.1 parts by mass of stannous octoate 17 parts by mass of 2,2-dimethylolpropionic acid, 47 parts by mass of ethylene glycol and 344 parts by mass of diphenylmethane diisocyanate are reacted until the solution viscosity reaches 20,000 mPa. After s, 3 parts by mass of methanol was added to stop the reaction, and a methyl ethyl ketone solution of the urethane resin (A-3) was obtained. In this urethane resin solution, 70 parts by mass of polyoxyethylene ethyl distyryl phenyl ether (HLB; 14) and 13 parts by mass of triethylamine are mixed, and then 800 parts by mass of ion-exchanged water is added thereto. The phase inversion emulsification was carried out, whereby an emulsion in which the above urethane resin (A-3) was dispersed in water was obtained.

Then, methyl ethyl ketone was distilled off from the emulsion, whereby an urethane resin composition (X-3) having a nonvolatile content of 40% by mass was obtained. Further, the content of the aromatic ring in the above urethane resin (A-3) was 1.93 mol/kg.

 [Example 1]  

100 parts by mass of the urethane resin composition (X-1) obtained in Synthesis Example 1, a thickener ("Borch Gel L75N" manufactured by Borcher Co., Ltd.), 5 parts by mass, and a carbodiimide crosslinking agent (Nissin Chemicals) 4 parts by mass of "Carbodilite SV-02" manufactured by the company, 200 parts by mass of ion-exchanged water, stirred at 2,000 rpm for 2 minutes in a mechanical kneader, and then defoamed by a vacuum defoamer, thereby preparing The blending solution.

Next, after the above-mentioned blending liquid was impregnated into a nonwoven fabric (basis weight: 250 g/m ² ), an unnecessary blending liquid was screwed out using a rubber roll mill to have an impregnation amount of 250%. Then, the nonwoven fabric containing the blending liquid was immersed in a coagulation bath of potassium sodium tartrate at 30 ° C for 10 minutes to solidify the blend liquid. Finally, it was dried by a hot air dryer at 120 ° C for 30 minutes to obtain a fibrous substrate having a coagulum.

 [Examples 2 to 6 and Comparative Examples 1 to 2]  

A fiber substrate having a coagulum was obtained in the same manner as in Example 1 except that the type of the urethane resin composition to be used and the type of the coagulant were changed as shown in Tables 1 and 2. .

 [Method for determining the number average molecular weight]  

The number average molecular weight of the polyol or the like used in the synthesis example is a value measured by a gel permeation chromatography (GPC) method under the following conditions.

Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)

Pipe column: The following columns manufactured by Tosoh Corporation are used in series.

"TSK gel G5000" (7.8mm I.D.×30cm) × 1

"TSK gel G4000" (7.8mm I.D.×30cm) × 1

"TSK gel G3000" (7.8mm I.D.×30cm) × 1

"TSK gel G2000" (7.8mm I.D.×30cm) × 1

Detector: RI (differential refractometer)

Column temperature: 40 ° C

Lysate: tetrahydrofuran (THF)

Flow rate: 1.0 mL/min

Injection amount: 100 μL (sample concentration 0.4% by mass in tetrahydrofuran solution)

Standard sample: A calibration curve was prepared using the following standard polystyrene.

 (standard polystyrene)  

"TSK gel standard polystyrene A-500" manufactured by Tosoh Corporation

"TSK gel standard polystyrene A-1000" manufactured by Tosoh Corporation

"TSK gel standard polystyrene A-2500" manufactured by Tosoh Corporation

"TSK gel Standard Polystyrene A-5000" manufactured by Tosoh Corporation

"TSK gel Standard Polystyrene F-1" manufactured by Tosoh Corporation

"TSK gel Standard Polystyrene F-2" manufactured by Tosoh Corporation

"TSK gel Standard Polystyrene F-4" manufactured by Tosoh Corporation

"TSK gel Standard Polystyrene F-10" manufactured by Tosoh Corporation

"TSK gel standard polystyrene F-20" manufactured by Tosoh Corporation

"TSK gel standard polystyrene F-40" manufactured by Tosoh Corporation

"TSK gel standard polystyrene F-80" manufactured by Tosoh Corporation

"TSK gel standard polystyrene F-128" manufactured by Tosoh Corporation

"TSK gel standard polystyrene F-288" manufactured by Tosoh Corporation

"TSK gel standard polystyrene F-550" manufactured by Tosoh Corporation

 [Method for Measuring Adhesion Amount of Ethyl Carbamate Resin on Fiber Substrate]  

The fibrous substrate having the coagulum obtained in the examples and the comparative examples was cut into 5 cm squares, and the mass was measured with a precision balance. The leather substrate was cut into 5 cm squares before the impregnation step, and the mass was measured with a precision balance. The difference between the masses of the two was measured, and the adhesion amount (g/cm ² ) of the urethane resin was determined.

 [Method for assessing the contamination of coagulation bath]  

The coagulation bath after the fiber substrate having the coagulation bath was produced by the naked eye in the examples and comparative examples, and was evaluated as follows.

"○": No agglomeration of the urethane resin was produced.

"△": Agglomeration of a urethane resin was slightly generated.

"X": Mass production of agglomerates of urethane resin.

 [Method for assessing coagulation]  

The fiber base material having the coagulation bath obtained in the examples and the comparative examples was twisted by both hands, and the surface of the fiber base material at this time was visually observed, and the following evaluation was performed.

"○": The screwing residue of the urethane resin was not produced.

"△": A crucible residue of the urethane resin was slightly produced.

"X": A large amount of the crushing residue of the urethane resin was produced.

In the examples 1 to 6 of the present invention, it is known that the urethane resin is not contaminated in the coagulation bath, and it has excellent coagulability to the extent that the urethane resin is not crushed when the coagulum is squeezed. .

On the other hand, in Comparative Examples 1 and 2, the salt of the acid having two or more carboxyl groups was replaced by another coagulant, and the urethane resin was contaminated in the coagulation bath, and it was produced when the coagulum was squeezed. The screwing residue of the urethane resin.

Claims (5)

 A method for producing a coagulum, characterized in that a hydrous urethane resin composition is solidified by a salt of an acid having two or more carboxyl groups.    The method for producing a coagulum of claim 1, wherein the solidification is carried out at a temperature lower than 40 °C.    A method of producing a coagulum according to claim 1 or 2, wherein the acid salt is a citrate salt and/or a tartrate salt.    The method for producing a coagulum according to any one of claims 1 to 3, wherein the urethane resin composition contains an anionic group-containing urethane resin.    The method for producing a coagulum according to any one of claims 1 to 4, which comprises impregnating a fibrous substrate with an aqueous urethane resin composition, and then immersing it in an acid salt having two or more carboxyl groups. A step of.