TW201842257A - Methods for producing porous body, glove and synthetic leather - Google Patents

Abstract

The present invention provides a method for producing a porous body, the method being characterized by coagulating an aqueous urethane resin composition using an aqueous solution of a metal-free coagulating agent. The present invention also provides a method for producing a glove having a coagulated film of the aqueous urethane resin composition, the method being characterized in that the coagulated film is obtained by immersing the aqueous urethane resin composition in an aqueous solution of a metal-free coagulating agent. The present invention also provides a method for producing a synthetic leather, the method being characterized by coating an aqueous urethane resin composition on a base fabric and then immersing the same in an aqueous solution of a metal-free coagulating agent. It is preferable to use an ammonium salt of an inorganic acid as the metal-free coagulating agent in order to achieve far better texture. The problem to be solved by the present invention is to provide a method for producing a glove having an excellent texture.

Description

 Porous body, glove, and method for producing synthetic leather  

The present invention relates to a method for producing a porous body, a glove, and a synthetic leather.

The aqueous urethane resin composition in which the urethane resin is dispersed in an aqueous medium can reduce the environmental load as compared with the conventional organic solvent urethane resin composition. It is used as a material for manufacturing synthetic leather, a coating agent, an adhesive, a glove, and the like.

The synthetic leather is generally composed of a fibrous base material such as a non-woven fabric, an intermediate layer, and a skin layer, and is used as a fibrous base material for improving the bending resistance and the hand feeling of the synthetic leather. The composition is impregnated with an aqueous urethane resin and subjected to a thermosetting coagulation (impregnation layer).

As the aqueous urethane resin composition for the impregnated layer, for example, an aqueous urethane resin composition containing a urethane resin having a carboxyl group and/or a sulfonic acid group and thermosensitive coagulation is disclosed. The agent and the aqueous medium (for example, refer to Patent Document 1).

However, in the solidification of the aqueous urethane resin composition by thermo-coagulation, the blending solution of the urethane resin is temporarily low-viscosity by heating, and the coating liquid is absorbed in the fibrous substrate. Further, the resin tends to adhere to the fiber entanglement point due to the capillary phenomenon, and the resin-constrained fiber indicates that the obtained synthetic leather is inferior in hand, and is inferior in flexibility and flexibility, and is easily broken.

Further, in the use of the glove, the film formed by the composition in which the aqueous polyurethane is blended is examined for the purpose of modifying the natural rubber or the synthetic rubber latex, and is formed on the surface of the fiber-based glove (for example, Refer to Patent Document 2).

However, in such a case, when the composition in which the aqueous polyurethane is blended is processed into a fiber base material or the like, since the urethane resin component is biased to exist on the surface of the fiber substrate, there is a feeling Hardening problem.

Prior technical literature Patent literature

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

Patent Document 2 Japanese Patent Laid-Open No. Hei 8-209415

An object of the present invention is to provide a production method in which a porous body having excellent hand feeling is obtained without using an organic solvent.

The present invention provides a method for producing a porous body characterized in that an aqueous urethane resin composition is solidified by an aqueous solution of a non-metallic coagulant. Moreover, the present invention provides a method for producing a glove, which is a method for producing a glove having a solidified film of an aqueous urethane resin composition, characterized in that the coagulating film is an aqueous urethane resin composition. Immersion in an aqueous solution of a non-metallic coagulant. Furthermore, the present invention provides a method for producing synthetic leather characterized in that an aqueous urethane resin composition is applied to a substrate and immersed in an aqueous solution of a non-metallic coagulant.

According to the production method of the present invention, a porous body excellent in hand can be obtained without using an organic solvent. Further, since metal ions are not contained as a coagulant, rust or deterioration of the manufacturing apparatus at the time of producing a coagulum is not caused. Therefore, the porous system obtained by the production method of the present invention can be applied to the manufacture of gloves and synthetic leather.

Fig. 1 is an electron micrograph (magnification: 200 times) showing a cross-sectional view of the porous body obtained in Example 4.

Form of implementing the invention

The method for producing a porous body of the present invention is to solidify an aqueous urethane resin composition by a non-metallic coagulant aqueous solution.

In the present invention, as the coagulant, it is necessary to use an aqueous solution of a non-metallic coagulant. In the present invention, by using a non-metallic coagulant, the aqueous urethane resin composition can be viscous, and a porous body excellent in hand feeling can be obtained. Further, by increasing the concentration of the coagulant, the solidification rate is increased, and a porous body having a more excellent hand feeling can be obtained.

The temperature of the aqueous solution of the non-metallic coagulant is preferably in the range of 10 to 100 ° C, more preferably in the range of 20 to 80 ° C, from the viewpoint of more easily obtaining the porous body. Further, in the present invention, the term "porous body" means a person having a large number of pores.

As the non-metallic coagulant, for example, ammonium chloride, tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride, tetrabutylammonium chloride, tetrahexylammonium chloride, chlorination can be used. Tetraoctyl ammonium, tetraphenylammonium chloride, triethylmethylammonium chloride, triethylhexylammonium chloride, trioctylmethylammonium chloride, trioctylbutylammonium chloride, trichloride Octylbenzylammonium, trimethylbenzylammonium chloride, tributylbenzylammonium chloride, triphenylisobutylammonium chloride, triphenylbenzylammonium chloride, ammonium bromide, bromide Methylammonium, tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetrahexylammonium bromide, tetraoctyl ammonium bromide, tetraphenylammonium bromide, triethyl bromide Methylammonium, triethylhexylammonium bromide, trioctylmethylammonium bromide, trioctylbutylammonium bromide, trioctylbenzylammonium bromide, trimethylbenzylammonium bromide, bromination Tributylbenzylammonium, triphenylisobutylammonium bromide, triphenylbenzylammonium bromide, ammonium iodide, tetramethylammonium iodide, tetraethylammonium iodide, tetrapropylammonium iodide , tetrabutylammonium iodide, tetrahexylammonium iodide, tetraoctyl ammonium iodide, iodine Tetraphenylammonium, triethylmethylammonium iodide, triethylhexylammonium iodide, trioctylmethylammonium iodide, trioctylbutylammonium iodide, trioctylbenzylammonium iodide, iodine Ammonium halide such as trimethylbenzylammonium, tributylbenzylammonium iodide, triphenylisobutylammonium iodide or triphenylbenzylammonium iodide; ammonium hydroxide, ammonium phosphate, ammonium borate, hydrogen Ammonium mineral acid such as ammonium fluorate, ammonium sulfate, ammonium nitrate, ammonium citrate or ammonium phosphate; ammonium organic acid such as ammonium formate, ammonium acetate, ammonium propionate, ammonium malate or ammonium sulfonate; Base acid, tetraphenylphosphonium iodide, tetramethylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium iodide, etc.; Organic acid bismuth and the like. These non-metallic coagulants may be used singly or in combination of two or more.

In the above-mentioned non-metallic coagulant, the viscosity of the aqueous urethane resin composition and the solidification rate are fast, and the adhesion of the resin to the fiber due to the capillary phenomenon can be suppressed and restrained. From the viewpoint of the hand, it is preferred to use an inorganic ammonium acid, more preferably ammonium sulfate.

As the water used in the aqueous solution of the non-metallic coagulant, for example, ion-exchanged water, distilled water, tap water or the like can be used. These water systems may be used singly or in combination of two or more.

The content of the non-metallic coagulant is preferably in the range of from 1 to 60% by mass, more preferably from 2 to 55% by mass, even more preferably from 25 to 50% by mass in the aqueous solution of the non-metallic coagulant.

As the aqueous urethane resin composition usable in the present invention, for example, an aqueous urethane resin (A) and an aqueous medium (B) can be used.

The aqueous urethane resin (A) can be dispersed in an aqueous medium (B) to be described later, and for example, an amine group having a hydrophilic group such as an anionic group, a cationic group or a nonionic group can be used. An acid ester resin; a urethane resin or the like which is forcibly dispersed in an aqueous medium (B) with an emulsifier. These aqueous 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, and further improve the aforementioned non-metallic coagulant by the electric double layer compression effect. A urethane resin having an anionic group is preferably used from the viewpoint of cohesiveness, easy porosity, and a more excellent hand.

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

As the compound having a carboxyl group, for example, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylol can be used. Propionic acid, 2,2-pentanoic acid, and the like. These compounds may be used singly or in combination of two or more.

As the compound having a sulfonyl group, for example, 3,4-diaminobutanesulfonic acid, 3,6-diamino-2-toluenesulfonic acid, 2,6-diaminobenzenesulfonic acid, N can be used. -(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 in the aqueous urethane resin composition may be partially or completely neutralized with a basic compound. As the basic compound, for example, ammonia, triethylamine, pyridine, or the like can be used. An organic amine such as a phenyl group, an alkanolamine such as monoethanolamine or dimethylethanolamine, or a metal base compound such as sodium, potassium, lithium or calcium.

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

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

The method of obtaining the urethane resin having a nonionic group is, for example, a method of using one or two or more kinds of compounds having an oxyethylene structure as a raw material.

As the compound having an oxyethylene structure, for example, a polyether polyol having an oxyethylene structure such as polyoxyethylene diol, polyoxyethylene polyoxypropylene diol or polyoxyethylene polyoxytetramethylene glycol can be used. These compounds may be used singly or in combination of two or more.

As the emulsifier which can be used for obtaining the urethane resin which is forcibly dispersed in the aqueous medium (B), for example, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, poly Nonionic emulsifier such as oxyethylene octadecyl phenyl ether, polyoxyethylene sorbitol tetraoleate, polyoxyethylene ‧ polyoxypropylene copolymer; fatty acid salts such as sodium oleate, alkyl sulfate salts Anionicity of alkylbenzenesulfonate, alkylsulfosuccinate, naphthalenesulfonate, polyoxyethylene alkyl sulfate, alkanesulfonate sodium salt, alkyl diphenyl ether sulfonate sodium salt, etc. An emulsifier; 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.

Specific examples of the aqueous urethane resin (A) include a polyisocyanate (a1), a polyol (a2), and a raw material for producing the aqueous urethane resin having a hydrophilic group. The desired chain extender (a3) is obtained as a raw material. Such reactions can be carried out using well known urethanation reactions.

The aqueous urethane resin (A) has low solubility in the coagulant used in the present invention, is easy to maintain a good solidified state, is easy to be porous, and further improves the hand feeling. It is preferred to use a urethane resin having an aromatic ring.

The content of the aromatic ring of the aqueous urethane resin (A) is preferably in the range of 0.8 to 8 mol/kg, more preferably in the range of 1 to 6 mol/kg.

The aromatic ring is supplied from any of the polyisocyanate (a1) and the polyol (a2) as a raw material, but from the viewpoint of easiness of production and stability of production, it is preferably from polyisocyanate (a1). To supply, it is preferred to use an aromatic polyisocyanate.

As the aromatic polyisocyanate, for example, phenyl diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, benzodimethyl diisocyanate, naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, carbon two can be used. Imidized diphenylmethane polyisocyanate and the like. These polyisocyanates may be used singly or in combination of two or more. Among these, diphenylmethane diisocyanate is preferably used from the viewpoint of easiness in obtaining raw materials and texture.

As the other polyisocyanate which can be used for the above polyisocyanate (a1), for example, hexamethylene diisocyanate, diazonic acid diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, or the like can be used. Benzyl diisocyanate, tetramethyl dimethyl diisocyanate, dimer acid diisocyanate, lower An aliphatic or alicyclic polyisocyanate such as an ene diisocyanate. These polyisocyanates may be used singly or in combination of two or more.

As the 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 polyol (a2) is preferably in the range of 500 to 8,000, more preferably in the range of 800 to 4,000, from the viewpoint of mechanical strength of the obtained film. Further, the number average molecular weight of the above polyol (a2) represents a value measured by a gel permeation chromatography (GPC) method.

As the chain extender (a3), for example, ethylenediamine, 1,2-propylenediamine, 1,6-hexamethylenediamine, and piperazine can be used. 2,5-Dimethyl pipe , isophorone diamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4'-dicyclohexylmethanediamine, a chain extender having an amine group such as 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, hydrazine or the like; ethylene glycol, diethylene glycol Alcohol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, sucrose, methyl glycol, glycerin, sorbus A chain extender having a hydroxyl group such as sugar alcohol, bisphenol A, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether or trimethylolpropane. These chain extenders may be used singly or in combination of two or more. Among these, a chain extender having a hydroxyl group is preferably used from the viewpoint of further improving oil grip and chemical resistance.

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

As the aqueous urethane resin (A), the content of the urea bond is preferably 1.2 mol/kg or less from the viewpoint of further controlling the discoloration over time without impairing the texture.

Since the aforementioned urea bond is formed when the above-mentioned chain extender having an amine group or an amine formed by reacting an isocyanate with water is reacted with the above polyisocyanate, by adjusting the amount of the chain extender having an amine group, further Before the emulsification operation, all of the isocyanate is urethane-modified, and the content of the urea bond of the aqueous urethane resin (A) can be adjusted. Further, the content of the aforementioned urea bond means a value calculated by the following formula (1).

As a method for producing the aqueous urethane resin (A), for example, a urethane prepolymer having an isocyanate group can be produced by reacting the polyisocyanate (a1) with the polyol (a2). And then, if necessary, a method of reacting the aforementioned urethane prepolymer with the chain extender (a3); adding the polyisocyanate (a1), the aforementioned polyol (a2) in batches, and optionally The chain extender (a3), the method of reacting it, and the like. These reactions are, for example, carried out at 50 to 100 ° C for 3 to 10 hours.

The hydroxyl group of the polyol (a2) and the hydroxyl group and the amine group of the chain extender (a3) and the molar ratio of the isocyanate group of the aromatic polyisocyanate (a1) [isocyanate group) /(hydroxyl and amine group)], preferably in the range of 0.8 to 1.2, more preferably in the range of 0.9 to 1.1.

When the aqueous urethane resin (A) is produced, it is preferred to inactivate the isocyanate group remaining in the aqueous urethane resin (A). When the isocyanate group is deactivated, it is preferred to use an alcohol having one hydroxyl group such as methanol. 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 aqueous urethane resin (A).

Further, in the production of the urethane resin (A), an organic solvent may also be used. As the organic solvent, for example, a ketone compound such as acetone or methyl ethyl ketone; tetrahydrofuran or two can be used. An ether compound such as an alkane; an acetate compound such as ethyl acetate or butyl acetate; a nitrile compound such as acetonitrile; a guanamine compound such as dimethylformamide or N-methylpyrrolidone. These organic solvents may be used singly or in combination of two or more. Further, in the case where the aqueous urethane resin composition is obtained, the organic solvent is preferably removed by distillation or the like.

Examples of the aqueous medium (B) include water, an organic solvent which can be mixed with water, a mixture thereof, and the like. 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; or ethylene glycol, diethylene glycol or propylene glycol; A polyalkylene glycol solvent; an alkyl ether solvent of a polyalkylene glycol; an internal guanamine 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 preferable to use only water, or a mixture of water and an organic solvent which can be mixed with water, from the viewpoint of safety and environmental load reduction, and it is more preferable to use only water.

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

The aqueous 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) described above.

As the other additives, for example, an emulsifier, a neutralizing agent, a tackifier, a crosslinking agent, a urethane catalyst, a decane coupling agent, a filler, a shake imparting agent, an adhesion-imparting agent, and a wax can be used. , heat stabilizer, light stabilizer, fluorescent brightener, foaming agent, pigment, dye, conductivity imparting agent, antistatic agent, moisture permeability improver, water repellent, oil remover, hollow foam , flame retardant, water absorbing agent, moisture absorbent, deodorant, foam stabilizer, anti-blocking agent, water-repellent agent, etc. These additives may be used singly or in combination of two or more.

The emulsifier may be the same as the emulsifier used in obtaining the aqueous urethane resin which is forcibly dispersed in the aqueous medium (B). These emulsifiers may be used singly or in combination of two or more. Among these, from the viewpoint of improving the water dispersion stability of the aqueous urethane resin (A) and further improving the hand feeling, it is preferred to use a nonionic emulsifier, HLB (hydrophilic parent). The oil balance is preferably 15 or less, more preferably 2 to 15.

As the above-mentioned nonionic emulsifier which can be preferably used, for example, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene distyrenated phenyl ether, polyoxyethylene lauryl can be used. Ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene sorbitol tetraoleate, and the like. These emulsifiers may be used singly or in combination of two or more.

The amount of use of the emulsifier is preferably in the range of 0.1 to 30 parts by mass based on 100 parts by mass of the aqueous urethane resin (A) from the viewpoint of water dispersion stability and texture. More preferably, it is in the range of 1 to 10 parts by mass.

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, potassium hydroxide or the like can be used. A volatile base; a tertiary amine compound such as trimethylamine, triethylamine, dimethylethanolamine, methyldiethanolamine or triethanol. These neutralizing agents may be used singly or in combination of two or more.

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

As described above, the aqueous urethane resin composition used in the present invention is preferably from the viewpoint of further solidification of the coagulant, further improvement of hand feeling, and improvement of water dispersion stability. An aqueous amine group containing an aqueous urethane resin (A) having an anionic group obtained by reacting an aromatic polyisocyanate, a polyol, and a chain extender, an aqueous medium (B), and a nonionic emulsifier An acid ester resin composition.

In the present invention, the aqueous urethane resin composition is solidified by a non-metallic coagulant aqueous solution, whereby a porous body can be easily obtained. The method for producing the porous body may, for example, be a method in which the aqueous urethane resin composition is applied to a substrate and immersed in the non-metallic coagulant aqueous solution.

As the substrate, for example, a base fabric, a polyester such as polyethylene terephthalate, polyethylene naphthalate or polybutylene terephthalate, polyolefin, polyacrylate, or poly can be used. a sheet or film obtained from vinyl chloride, polyethylene, polypropylene ethylene vinyl alcohol, polyurethane, polyamide, polyimide, etc.

As the base fabric, for example, a nonwoven fabric, a woven fabric, a knitted fabric, or the like can be used. As the fiber substrate, for example, polyester fiber, nylon fiber, acrylic fiber, polyurethane fiber, acetate fiber, ray fiber, polylactic acid fiber, cotton, hemp, silk, wool, or the like can be used. These blended fibers, etc.

The method of applying the aqueous urethane resin composition to the substrate is, for example, a roll coater, a knife coater, a spray coater, a gravure coater, a slant coater, or a T-die coating. Machine, applicator, etc.

Next, the coated product is further immersed in the coagulation bath of the aqueous solution of the non-metallic coagulant to solidify the urethane resin in the aqueous urethane resin composition to obtain a porous body. The immersion and solidification time at this time is, for example, in the range of 1 to 30 minutes.

After the porous body is obtained, it may be immersed in running water, for example, for 10 minutes to 2 hours after solidification, and the unnecessary coagulant may be washed and removed.

As described above, according to the production method of the present invention, a porous body excellent in hand feeling can be obtained without using an organic solvent. Further, since the coagulant does not contain metal ions, it does not cause rust or deterioration of the manufacturing apparatus at the time of producing a coagulum. Therefore, the porous system obtained by the production method of the present invention can be applied to the manufacture of gloves and synthetic leather.

As a method of producing the glove when the porous body is used in the production of a glove, for example, a hand die, a tube die, or the like is first immersed in the aqueous urethane resin composition, and then the hand die or the like is impregnated. After the aqueous solution of the non-metallic coagulant is washed with water, the surface is washed and dried to form a solidified film on the surface of the hand mold or the like. Further, the order of impregnation of the aqueous urethane resin composition and the aqueous solution of the non-metal coagulant may be exchanged.

The hand mold or the tube mold may be at room temperature when immersed in the aqueous urethane resin composition, or may be heated to, for example, 30 to 70 °C.

Further, a glove or a tubular member made of a knitted fabric such as nylon fiber may be attached to the hand mold or the tubular mold in advance.

The knitted fabric is not limited to the above-mentioned nylon fibers, and those composed of polyester fibers, aromatic polyamide fibers, cotton, or the like can be used. Further, in place of the knitted fabric, a woven fabric composed of the above fibers may be used. Further, instead of the knitted fabric, a glove or a tube made of a resin material such as vinyl chloride, natural rubber or synthetic rubber may be used.

Further, when the porous body is used in the production of synthetic leather, a synthetic fabric having an intermediate layer of a base fabric and a porous body can be obtained by using a base fabric as the base material. Further, on the intermediate layer, a skin layer may be provided as needed. As a method of producing a skin layer on the intermediate layer, for example, a method of applying a material capable of forming a skin layer to the intermediate layer and drying it can be mentioned.

As a material for forming the above-mentioned skin layer, for example, a well-known aqueous urethane resin, a solvent urethane resin, a solventless urethane resin, an aqueous acrylic resin, a polyoxyl resin, or a polypropylene can be used. Resin, polyester resin, etc. These resins may be used singly or in combination of two or more.

After the synthetic leather is produced, it may be cooked at 30 to 100 ° C for 1 to 10 days as needed.

The synthetic leather obtained by such a method can be easily produced into a smooth porous body without being affected by the unevenness of the base fabric, for example, in comparison with the case where the base material is impregnated with the aqueous urethane resin composition. . Further, even when the porous body is a thick film, it is extremely soft, and further, a buffer layer made of a porous body is formed on the surface, and the flexibility is also excellent.

Example

Hereinafter, the present invention will be described in more detail by way of examples.

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

1,000 parts by mass of a polycarbonate polyol ("Nippollan 980R" Japan Polyurethane Co., Ltd., in the presence of 3,281 parts by mass of methyl ethyl ketone and 0.1 parts by mass of stannous octoate Average molecular weight; 2,000), 17 parts by mass of 2,2-dimethylolpropionic acid, 47 parts by mass of ethylene glycol and 344 parts by mass of diphenylmethane diisocyanate were reacted at 70 ° C until the solution viscosity reached 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 aqueous urethane resin (A-1) was obtained. In this urethane resin solution, 70 parts by mass of polyoxyethylene distyrenated phenyl ether (hydrophilic-lipophilic balance (hereinafter referred to as "HLB"): 14) and 13 parts by mass of triethylamine are mixed. Then, 800 parts by mass of ion-exchanged water was added to cause phase inversion emulsification, and an emulsion in which the aqueous urethane resin (A-1) was dispersed in water was obtained.

Then, methyl ethyl ketone was distilled off from the emulsion to obtain an aqueous urethane resin composition (X-1) having a nonvolatile content of 40% by mass.

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

1,000 parts by mass of a polyether polyol ("PTMG2000" Mitsubishi Chemical Co., Ltd., number average molecular weight; 2,000), 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 were reacted at 70 ° C until the solution viscosity reached 20,000 mPa ‧ s, and 3 was added. The reaction was stopped with a mass of methanol to obtain a methyl ethyl ketone solution of the aqueous urethane resin (A-2). In this urethane resin solution, after 70 parts by mass of polyoxyethylene distyrenated phenyl ether (HLB: 14) and 13 parts by mass of triethylamine were mixed, 800 parts by mass of ion-exchanged water was added thereto. The phase inversion was emulsified to obtain an emulsion in which the aqueous urethane resin (A-2) was dispersed in water.

Then, methyl ethyl ketone was distilled off from the emulsion to obtain an aqueous urethane resin composition (X-2) having a nonvolatile content of 40% by mass.

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

1,000 parts by mass of polyester polyol ("Placcel 220" DAICEL Co., Ltd., number average molecular weight; 2,000), 17 in the presence of 3,281 parts by mass of methyl ethyl ketone and 0.1 part by mass of stannous octoate A mass part of 2,2-dimethylolpropionic acid, 47 parts by mass of ethylene glycol and 344 parts by mass of diphenylmethane diisocyanate are reacted at 70 ° C until the solution viscosity reaches 20,000 mPa ‧ s, and 3 mass is added The reaction was stopped with a portion of methanol to obtain a methyl ethyl ketone solution of the aqueous urethane resin (A-3). In this urethane resin solution, after 70 parts by mass of polyoxyethylene distyrenated phenyl ether (HLB: 14) and 13 parts by mass of triethylamine were mixed, 800 parts by mass of ion-exchanged water was added thereto. The phase inversion was emulsified to obtain an emulsion in which the aqueous urethane resin (A-3) was dispersed in water.

Then, methyl ethyl ketone was distilled off from the emulsion to obtain an aqueous urethane resin composition (X-3) having a nonvolatile content of 40% by mass.

 [Example 1]  

100 parts by mass of the aqueous urethane resin composition (X-1) obtained in Synthesis Example 1, 5 parts by mass of a tackifier (Borch Gel L75N manufactured by Borcher Co., Ltd.), and 4 parts by mass of carbon dioxide An amine crosslinking agent ("Carbodilite SV-02" manufactured by Nisshin Chemical Co., Ltd.) and 100 parts by mass of ion-exchanged water were stirred in a mechanical mixer at 2,000 rpm for 2 minutes, followed by defoaming with a vacuum deaerator. , modulate the blending solution.

Next, a glove knitted with nylon fibers was attached to the hand mold, and immersed in the above-mentioned blending liquid for 15 seconds, and then hanged. Subsequently, the hand mold was immersed in a coagulation bath heated to 60 ° C in an ammonium sulfate 40% by mass aqueous solution for 3 minutes, and then hanged. Continuing, the hand mold was immersed in water for 60 minutes, the excess coagulant was washed, and dried at 120 ° C for 30 minutes. Then, the woven glove was taken out from the hand mold to obtain a glove having a solidified film of the aqueous urethane resin composition.

 [Examples 2 to 3]  

A glove was obtained in the same manner as in Example 1 except that the type of the aqueous urethane resin composition used was changed as shown in the table.

 [Comparative Example 1]  

100 parts by mass of the aqueous urethane resin composition (X-1) obtained in Synthesis Example 1 and 100 parts by mass of a sodium chloride 2% by mass aqueous solution were stirred at 2,000 rpm for 2 minutes using a mechanical mixer. , and the blending solution is prepared.

Next, a glove knitted with nylon fibers was attached to the hand mold, and immersed in the above-mentioned blending liquid for 15 seconds, and then hanged. Subsequently, it was dried at 120 ° C for 30 minutes. Then, the woven glove was taken out from the hand mold to obtain a glove having a thermosensitive coagulation film of the aqueous urethane resin composition.

 [Comparative Example 2]  

In the same manner as in Example 1, except that in the first embodiment, a coagulation bath of a 40% by mass aqueous solution of ammonium sulfate heated to 60 ° C was used, and a coagulation bath of a 20% by mass aqueous solution of sodium chloride at 60 ° C was used. A glove having a coagulated film of an aqueous urethane resin composition.

 [Method for determining the number average molecular weight]  

The number average molecular weight of the polyol or the like used in the synthesis example means 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 string: It is used by connecting the following pipe columns manufactured by Tosoh Corporation in series.

"TSKgel G5000" (7.8mmI.D.×30cm) × 1

"TSKgel G4000" (7.8mmI.D.×30cm) × 1

"TSKgel G3000" (7.8mmI.D.×30cm) × 1

"TSKgel G2000" (7.8mmI.D.×30cm) × 1

Detector: RI (differential refractometer)

Column temperature: 40 ° C

Eluent: 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 standard polystyrene described below.

 (standard polystyrene)  

"TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation

"TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

 [Evaluation method of odor during processing]  

The odor was smelled 1 m above the coagulation bath layer during processing, and was evaluated as follows.

"T"; feels stinky.

"F"; no smell.

 [Method for Evaluating Adhesion State of Aqueous Urethane Resin to Fiber Substrate]  

Using the scanning electron microscope "SU3500" manufactured by Hitachi High-Technologies Corporation (200 times magnification), the gloves obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were observed and evaluated as follows.

"T"; the aqueous urethane resin layer formed on the nylon fiber was observed to have a porous structure.

"F"; the porous urethane resin layer formed on the nylon fiber did not have a porous structure.

 [Method of evaluation of hand feeling]  

The gloves obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated by the following feelings by hand contact.

"A"; both stiff and full.

"B"; you can feel a sense of stiffness and fullness.

"C"; a stiff feeling and a feeling of fullness.

"D"; no feeling of stiffness or fullness at all.

 [Example 4]  

100 parts by mass of the aqueous urethane resin composition (X-1) obtained in Synthesis Example 1, 5 parts by mass of a tackifier (Borch Gel L75N manufactured by Borcher Co., Ltd.), and 4 parts by mass of carbon dioxide An amine crosslinking agent ("Carbodilite SV-02" manufactured by Nisshin Chemical Co., Ltd.) and 100 parts by mass of ion-exchanged water were stirred in a mechanical mixer at 2,000 rpm for 2 minutes, followed by defoaming with a vacuum deaerator. , modulate the blending solution.

Next, the above-mentioned blending liquid was applied onto the surface of the nonwoven fabric substrate by knife coating (gap 100 μm). Subsequently, the coated substrate was immersed in an aqueous solution of 40% by mass ammonium sulfate heated to 60 ° C for 3 minutes to solidify the coating film. After the immersion, the excess coagulant was washed by immersing in water for 60 minutes, and dried at 120 ° C for 30 minutes to obtain an intermediate layer for synthetic leather.

 [Examples 5 to 6]  

An intermediate layer for synthetic leather was obtained in the same manner as in Example 1 except that the type of the aqueous urethane resin composition used was changed as shown in the Table.

 [Evaluation method of odor during processing]  

The odor was smelled 1 m above the coagulation bath layer during processing, and was evaluated as follows.

"T"; feels stinky.

"F"; no smell.

 [Method for Evaluating Adhesion State of Aqueous Urethane Resin to Fiber Substrate]  

The intermediate layer for synthetic leather obtained in Examples 4 to 6 was observed using a scanning electron microscope "SU3500" (magnification: 200 times) manufactured by Hitachi High-Technologies Corporation, and evaluated as follows.

"T"; an aqueous urethane resin layer formed on the surface of the base fabric, a porous structure was observed.

"F"; the porous urethane resin layer formed on the surface of the base fabric did not have a porous structure.

 [Method of evaluation of hand feeling]  

The intermediate layers for synthetic leather obtained in Examples 4 to 6 were evaluated by the following feelings by hand contact.

"A"; both stiff and full.

"B"; you can feel a sense of stiffness and fullness.

"C"; a stiff feeling and a feeling of fullness.

"D"; no feeling of stiffness or fullness at all.

Explain the abbreviations in Tables 1~2.

"MDI"; diphenylmethane diisocyanate

It is understood that the gloves obtained in Examples 1 to 3 of the present invention and the synthetic leathers obtained in Examples 4 to 6 are excellent in hand. Moreover, since no organic solvent was used, no problem of odor occurred.

On the other hand, in Comparative Example 1, the solidification was caused by thermocoagulation, but the hand feeling was poor.

In Comparative Example 2, a non-metallic coagulant was used instead of the coagulation bath of the metal salt, but the handle was poor.

Claims (8)

 A method for producing a porous body, characterized in that the aqueous urethane resin composition is solidified by a non-metallic coagulant aqueous solution.    The method for producing a porous body according to claim 1, wherein the non-metallic coagulant is ammonium mineral acid.    The method for producing a porous body according to claim 1 or 2, wherein the aqueous urethane resin composition contains an aqueous urethane resin (A) having an aromatic ring.    The method for producing a porous body according to claim 3, wherein the content of the aromatic ring of the aqueous urethane resin (A) is in the range of 0.8 to 8 mol/kg.    The method for producing a porous body according to claim 3 or 4, wherein the aqueous urethane resin (A) is an aromatic polyisocyanate as a raw material.    The method for producing a porous body according to claim 5, wherein the aromatic polyisocyanate is diphenylmethane diisocyanate.    A method for producing a glove, which is a method for producing a glove having a solidified coating of an aqueous urethane resin composition, characterized in that an aqueous urethane resin composition is immersed in an aqueous solution of a non-metallic coagulant to form Coagulation of the membrane.    A method for producing synthetic leather, which comprises applying an aqueous urethane resin composition to a substrate and immersing it in an aqueous solution of a non-metallic coagulant.