JP2001233987A - Method of manufacturing urethane porous product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing urethane porous products which can effect extrusion molding into the form of a shaped article such as a thick product and can form uniform and dense porous products in the wet coagulation method using a polyurethane based resin. SOLUTION: The method of manufacturing urethane porous products by the wet coagulation method comprises dissolving a polyurethane based resin in dimethylformamide, adding a water-soluble polymer, a surface active agent and, if necessary, an auxiliary, a pigment or the like thereto and kneading them therewith to form a mixture, cooling the discharge temperature of the mixture at the molding die portion of an extruder to a temperature capable of forming the mixture into a shaped article, forming the mixture into a shaped article while extruding it through the molding die, dipping the mixture of the shaped article in an aqueous solution to coagulate it and simultaneously dissolving the water-soluble polymer to remove it. By this method, shaped articles can be obtained in a cubic form by the wet coagulation method, and the molding of porous products having uniform and dense cells without surface roughness, and cushioning materials of urethane porous products, cosmetic sponges, rolls of office automation equipment, electrically conductive rolls, electrically conductive cushions and the like can also be rendered possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a urethane porous body, and a method for producing a porous body having a thickness of about 5 to 15 mm by extrusion molding by a wet coagulation method using a urethane resin. It is made possible.

[0002]

2. Description of the Related Art A urethane porous material using a urethane resin such as polyurethane is used as a cushion material, a sponge for cosmetics, a roll for OA equipment, a conductive roll, a conductive cushion, and the like.

[0003] As a method for producing such a urethane porous body, there is a foaming method as a general method. For example, a polyurethane resin which is a raw material of a thermoplastic resin is mixed with a chemical blowing agent such as azodicarbonamide. A method of generating a gas by thermally decomposing a chemical foaming agent by the heat of melting the thermoplastic resin raw material or injecting a gaseous gas such as water vapor, nitrogen or carbon dioxide gas as a physical foaming agent into the molten thermoplastic resin There is a method to do.

[0004] A wet coagulation method is known as a method for producing a thin urethane porous body such as synthetic leather having a thickness of at most about 1 mm. For example, a polyurethane resin solution is applied on a fiber base material, and the resulting solution is immersed in a dimethylformamide aqueous solution. There is a method in which a sheet-like material having a porous polyurethane-based resin layer on the surface is obtained by immersing the resin to solidify the polyurethane-based resin, removing the solvent, washing, and drying.

[0005]

In such a production method by foam molding, foaming is carried out with a pyrolysis gas or a separately injected gas in a state where the resin raw material is melted and the viscosity is extremely reduced. The bubble state changes greatly due to slight pressure fluctuations of the pyrolysis gas or injected gas,
It is difficult to obtain a uniform and dense molded product, and the gas easily escapes to the outside, and it is difficult to obtain a stable foamed molded product.

Particularly, in the case of extrusion molding, when the resin in the foamed state passes through the die, the gas further expands due to a sudden drop in pressure, whereby fine irregularities are formed on the surface of the molded product, resulting in a shark skin shape. There is a problem that a rough surface easily occurs and a clean surface cannot be obtained.

On the other hand, in the wet coagulation method, a porous material is immersed in an aqueous solution of dimethylformamide to coagulate the polyurethane resin, and then the solvent is removed, washed, and dried to obtain a porous material. However, it cannot be formed into a die shape such as extrusion molding, and there is a problem that it can only be applied to a fiber substrate to form a sheet having a thickness of about 1 mm.

The present invention has been made in view of the above-mentioned problems in the prior art, and can be formed into a product such as a thick product by a wet coagulation method using a polyurethane resin, and can be extruded into a uniform product. An object of the present invention is to provide a method for producing a urethane porous body that can be made into a porous body.

[0009]

The inventors of the present invention have conducted intensive studies on the wet coagulation method that has been carried out so far. As a result, the mixture of the polyurethane resin is cooled to suppress the heat of reaction between the constituent materials. The temperature at the portion discharged from the die was close to room temperature, and the viscosity of the mixture increased very little, so that the mixture could not be formed into a three-dimensional shape even when it could be applied in a sheet form.

Therefore, it was found that it would be sufficient if the state of the mixture at the die discharge portion could be three-dimensionally shaped, and molding conditions for realizing this were found, and the present invention was completed. Cool the mixture to a state where the mixture can be shaped, and improve the composition of the mixture so that it can be cooled down to about room temperature since cooling alone requires a lot of cooling energy. This is because the conditions of immersion water for removing the polymer to make it porous are appropriately selected.

[0011] In order to solve the above-mentioned problems of the prior art, a method for producing a urethane porous body according to claim 1 of the present invention is characterized in that when a urethane porous body is produced by a wet coagulation method, a polyurethane resin is converted into dimethylformamide. While dissolving in water, a water-soluble polymer and a surfactant are added and kneaded to form a mixture, and the mixture discharge temperature of the molding die portion of the extruder is cooled to a temperature at which the mixture can be shaped, and the mixture is extruded from the molding die. It is characterized by shaping, shaping the shaped mixture into an aqueous solution, coagulating, and dissolving and removing the water-soluble polymer.

According to this method for producing a urethane porous body, when the urethane porous body is produced by a wet solidification method,
A polyurethane resin is dissolved in dimethylformamide, and a water-soluble polymer, a surfactant, and, if necessary, an auxiliary agent and a pigment are added and kneaded to form a mixture. The mixture is extruded from a molding die of an extruder to obtain a desired shape. In order to shape the mixture, it is necessary to adjust the temperature of the mixture at the forming die discharge section.

In the production of ordinary urethane porous material, this temperature is preferably -5 to 5 ° C. -5
When the temperature is lower than 0 ° C., the fluidity at the time of discharge decreases, and the surface of the urethane porous body is undesirably roughened. On the other hand, if this temperature exceeds 5 ° C., it is not preferable because the moldability deteriorates.

Next, the mixture extruded and shaped from the molding die is immersed and solidified in an aqueous solution, and the water-soluble polymer in the shaped mixture is dissolved and eluted and removed from the mixture. The portion where the water-soluble polymer eluted in the shaped mixture becomes a void portion, which is taken out of the aqueous solution and dried to obtain the porous body of the present invention.

Thus, a product shaped into a three-dimensional shape by the wet coagulation method can be formed, and a porous body having dense cells without surface roughness can be obtained.

The voids are formed, taken out of the aqueous solution, and dried to obtain the porous body of the present invention.

According to a second aspect of the present invention, there is provided a method for producing a urethane porous body, wherein in addition to the first aspect, a thickener is added to and mixed with the mixture to form a mixture of the molding die of an extruder. The mixture discharge temperature is set to 0 to 15 ° C.

According to this method for producing a urethane porous body, a thickener is added to and mixed with the mixture to increase the viscosity of the mixture, so that the mixture is extruded from a molding die of an extruder and formed into a desired shape. The temperature of the mixture at the forming die discharge section for forming the mold is reduced from the normal -5 to 5 ° C.
It is possible to reach 5 ° C. Since the temperature is close to room temperature, the temperature can be easily adjusted, and the quality of the product can be stabilized.

Furthermore, the method for producing a urethane porous body according to claim 3 of the present invention is characterized in that, in addition to the constitution of claim 1 or 2, the aqueous solution in which the shaped mixture is immersed has a water temperature of 20 to 60 ° C. It is characterized by having.

According to this method for producing a urethane porous body, the aqueous solution in which the shaped mixture is immersed has a water temperature of 20 to 6
When the temperature is 0 ° C., the water-soluble polymer in the shaped mixture can be efficiently dissolved and eluted, and a porous body having uniform and dense cells can be obtained. When the water temperature is lower than 20 ° C., the dissolution and elution of the water-soluble polymer becomes insufficient, which may result in a porous body with reduced cell denseness. When the water temperature exceeds 60 ° C., the water-soluble polymer is completely dissolved and eluted, but the shaped mixture is insufficiently solidified, which may cause a shape problem.

According to a fourth aspect of the present invention, there is provided a method for producing a urethane porous material according to any one of the first to third aspects, wherein the aqueous solution is a 10 to 50% aqueous dimethylformamide solution. It is characterized by having.

According to this method for producing a urethane porous body, by dissolving and eluting a water-soluble polymer by using an aqueous solution of dimethylformamide having a concentration of 10 to 50%, an excellent porous body can be obtained. This makes it easy to obtain a porous body having uniform and dense cells even when the temperature of the aqueous solution is lower than 20 ° C. If the concentration is less than 10%, a remarkable effect may not be obtained.
If it exceeds 0%, the case where the water-soluble polymer is difficult to dissolve and elute is likely to occur, which is not preferable.

Here, the polyurethane-based resin includes a polyurethane resin, a polyurethane-based elastomer, and the like, to which a necessary additive such as a lubricant, a plasticizer, and an antioxidant is added. .

In addition to the polyurethane resin, PS
In some cases, a polymer material such as (polystyrene), PE (polyethylene), PP (polypropylene), an acrylic resin, or polyamide is used, and a composite of those polymer materials is also used.

The water-soluble polymer material is a polymer which is hardly soluble in DMF (dimethylformamide) which dissolves a polyurethane resin and is soluble in water, such as PVA (polyvinyl alcohol), polyethylene oxide, and water-soluble polymer. Vinylon, HEC (hydroxyethyl cellulose), MC (methyl cellulose), CM as various celluloses
Α- as various starches such as C (carboxymethylcellulose) and HPC (hydroxypropylcellulose)
Glucose and sugar as high-molecular polysaccharides such as starch, dextrin, rice starch, corn starch, etc. can be raised. Things.

Examples of the surfactant include sodium dioctyl sulfosuccinate, castor oil, glycerin / tripalmitate, and silicone oil.
When these are used alone or in combination, they are effective in adjusting the solidification rate, good planar smoothness, forming fine cells, and the like. The amount of addition is appropriately determined depending on the use of the resin or the porous body.

Examples of the thickener include highly crystalline urethane, polyamide, polyurethane, AS resin (acrylic
Resin blends such as styrene copolymers), silica, mica and the like. By adding these thickeners to the mixture, the viscosity of the mixture is increased, and by increasing the moldable temperature, the room temperature is increased. Molding at a temperature close to
The temperature control becomes easy, and it becomes possible to easily and stably produce a porous body of uniform and dense cells. The amount of addition is appropriately determined depending on the use of the resin or the porous body.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be specifically described below.

In the method for producing a urethane porous body according to the present invention, dimethylformamide (D) using a polyurethane resin as a solvent is used, as in the wet coagulation method using a polyurethane resin.
MF), is difficult to dissolve in this solvent, dimethylformamide (DMF), and is mixed with a water-soluble polymer that dissolves in water, and a surfactant and necessary auxiliaries are added and mixed. Obtain a mixture.

The mixture is extruded with a screw of an extruder, shaped by a die, and discharged. However, while extruding with a screw, a cooling medium such as cooling water is supplied to remove the reaction heat of the mixture. Instead, the mixture is cooled so that the discharge temperature of the mixture from the die becomes a temperature at which the mixture can be shaped.

The temperature at which the mixture can be cooled differs depending on the type of the polyurethane resin or the water-soluble polymer, but the molding conditions of the polyurethane resin in the wet coagulation method are from -5 ° C to 5 ° C. Cool to about ° C.

By cooling to such a temperature range,
In the case of cooling for removing the reaction heat of the mixture in the conventional wet coagulation method, the discharge temperature from the die is set to normal temperature, for example, 1
The viscosity of the mixture can be increased as compared with the case where the temperature is 5 to 20 ° C. It can be shaped into a three-dimensional shape such as a cylindrical shape or a flat shape having a thickness of about 5 to 15 mm.

The mixture thus shaped into a die by extrusion molding is immersed in an aqueous solution and solidified.
The aqueous solution here means either water or an aqueous solution of another substance, for example, water or dimethylformamide (DM
The aqueous solution of F) is used, and the shaped mixture is immersed in an aqueous solution tank and solidified.

The aqueous solution tank is usually set at room temperature, for example, at about 15 to 20 ° C.

The shaped article immersed in the aqueous solution tank and solidified in this way is replaced with water in the solvent (DMF) contained in the shaped article and gelled. At the same time, a part of the water-soluble polymer in the shaped product is extracted into water.

Thereafter, by maintaining the state of being immersed in water, the water-soluble polymer in the molded article is dissolved and eluted, and fine pores corresponding to the water-soluble polymer are formed in the molded article. It becomes a product of a porous body by drying.

Through these steps, a product obtained by the wet coagulation method of the polyurethane resin can be formed as a porous body, and a porous product can be obtained in a cylindrical or flat shape formed by a die. .

Examples of the urethane-based resin that can be used in the method for producing such a urethane porous body include a polyurethane resin and a polyurethane-based elastomer, and other necessary auxiliaries such as a lubricant,
A plasticizer, an antioxidant and the like are added and used.

This polyurethane resin is previously dissolved in dimethylformamide (DMF), and then mixed with other components.

The water-soluble polymer for forming a porous material is a polymer which is hardly soluble in DMF (dimethylformamide) which dissolves a polyurethane resin and is soluble in water. For example, PVA (polyvinyl) Alcohol), polyethylene oxide, water-soluble vinylon, HEC (hydroxyethyl cellulose) as various celluloses, MC
(Methylcellulose), CMC (carboxymethylcellulose), HPC (hydroxypropylcellulose)
Α-starch as various starches, dextrin,
Examples of high-molecular-weight polysaccharides such as rice starch and corn starch include glucose and sugar.

This mixture is composed of polyurethane resins 20 to 4
0% by weight, dimethylformamide (DMF) 10 to 30
%, 30 to 60% by weight of a water-soluble polymer, and 1 to 5% by weight of a surfactant.

In such a method for producing a urethane porous body, a mixture of a polyurethane resin is kneaded, and then the mixture is −5 ° C. to 5 ° C.
A cooling chiller is installed as a cooling facility to circulate the antifreeze brine because it is necessary to cool and shape the mold to a certain degree.However, such a cooling facility is required, which increases equipment costs and product costs. Will be invited.

Therefore, as a molding condition that can be cooled by circulation of tap water or the like and does not require special cooling equipment, a thickener is added to improve the composition of the polyurethane resin mixture.

As the thickener, a high-viscosity resin or a substance having a so-called thickening effect is used. For example, high-viscosity resins such as highly crystalline urethane, polyamide, polyurethane, and AS resin (acryl / styrene copolymer) are used. And silica and mica as substances having a thickening effect.

These thickeners are based on the mixture
The mixture is mixed at a ratio of 1 to 5% by weight. By adding this thickener, the temperature at which the mixture is cooled to a state where the mixture can be shaped can be increased.
C., the shaped porous body can be formed, the cooling equipment does not require a low-temperature chiller, and it can be dealt with by cooling by circulating tap water.

On the other hand, the mixture that has been cooled and shaped into a die is immersed in an aqueous solution, solidified, and then maintained in a state of being immersed in water. Is dissolved and eluted to form fine pores corresponding to the water-soluble polymer in the shaped article. In this case, the dissolution of the water-soluble polymer greatly changes depending on the conditions of the aqueous solution tank.

By using water as the condition of the aqueous solution tank and setting the temperature to 20 to 60 ° C., the dissolution and removal of the water-soluble polymer can be promoted.

As the condition of the aqueous solution tank, dimethylformamide (DM
By making the concentration of F) an aqueous solution of 10 to 50% by weight,
Dissolution and removal of the water-soluble polymer can be promoted.

Therefore, the mixture which has been cooled and shaped into the shape of a die can be placed in an aqueous solution tank containing water at a temperature of 20 to 60 ° C., or dimethylformamide (D
By immersing in a water bath having a concentration of MF) of 10 to 50% by weight, dissolution and removal of the water-soluble polymer can be promoted, and a uniform and dense porous body can be obtained. It is possible to obtain a shaped product having excellent cushioning properties and feeling.

Thus, a cushion material of a urethane porous body using a urethane resin, a sponge for cosmetics, an OA
It can be used as a roll for equipment, a conductive roll, a conductive cushion and the like.

[0051]

EXAMPLES Examples of the present invention and comparative examples will be described below, but the present invention is not limited to these examples.

(1) Regarding the Temperature of the Die Discharge Portion (Example 1) 20% by weight of dimethylformamide (DMF), 30% by weight of a polyurethane resin (polyester urethane elastomer (manufactured by Dainichi Seika)), and a water-soluble polymer 30% by weight of polyvinyl alcohol (PVA),
18% by weight of carboxymethyl cellulose (CMC),
2% by weight of sodium dioctyl sulfosuccinate was added as a surfactant and kneaded to obtain a mixture.

The mixture was kneaded with a rotary kneader for 20 minutes, the temperature of the die discharge portion was set to -3 ° C. by using a cooling type single screw extruder, and the mixture was formed into a plate having a thickness of 15 mm from the die at 30 ° C. Was discharged into an aqueous solution tank containing water, soaked and solidified.

Then, it was placed in an aqueous solution tank (extraction tank) containing water at a temperature of 40 ° C., left for 3 hours, and dried in an oven at 60 ° C. for 4 hours to obtain a shaped product.

The surface smoothness, shrinkage state, curling state (warpage), shape-retaining property (plate shape), and porous state of the thus obtained shaped article were observed.

As a result, as shown in Table 1, the obtained shaped article had a good surface smoothness, a small shrinkage phenomenon, no curling phenomenon (warpage), and a flat shape (good shape preservability). ), The porous state was also uniform.

(Embodiment 2) The temperature of the die discharge portion was 5 ° C.
A 15 mm flat plate-shaped molded product was molded under the same conditions as in Example 1 except that the above conditions were changed.

As shown in Table 1, the obtained shaped product had a good surface smoothness, a small shrinkage phenomenon, no curling phenomenon (warpage), and a flat shape (shape preservation), as shown in Table 1. (The moldability was good) and the porous state was uniform.

(Comparative Example 1) The temperature of the die discharge portion was set to -1
15 mm under the same conditions as in Example 1 except that the temperature was changed to 0 ° C.
Was molded.

As shown in Table 1, the obtained shaped article had irregularities on the surface, exhibited a large shrinkage phenomenon,
A curling phenomenon (warpage) was also observed, the shape retention of the flat plate was poor, and the plate was in an incomplete porous state.

(Comparative Example 2) The temperature of the die discharge portion was set to 20
Except that the temperature was changed to ° C., a 15 mm flat plate-shaped molded product was molded under the same conditions as in Example 1.

As shown in Table 1, the obtained shaped article had irregularities on its surface, a shrinkage phenomenon was observed, and a curling phenomenon (warpage) was also observed. It was of good quality.

[0063]

[Table 1]

(2) About the immersion temperature or components of the shaped article in the aqueous solution tank (Example 3) A mixture having the same composition as in Example 1 was used.
While shaping into a plate shape of m, the immersion temperature was set to 40 ° C., and the mixture was discharged into an aqueous solution tank containing water, immersed and solidified.

Then, it was placed in an aqueous solution tank (extraction tank) containing water at a temperature of 40 ° C., left for 3 hours, and dried in an oven at 60 ° C. for 4 hours to obtain a shaped product.

The surface smoothness, shrinkage state, curling state (warpage), shape-retaining property (plate shape), and porous state of the thus obtained shaped article were observed.

As a result, as shown in Table 2, the obtained shaped product had a good surface smoothness, a small shrinkage phenomenon, no curling phenomenon (warpage), and a flat shape (good shape retention). ), The porous state was also uniform.

Example 4 The same conditions as in Example 3 were adopted except that the temperature for immersing the shaped article in the aqueous solution tank was changed to 60 ° C.
A 5 mm flat shaped article was molded.

As shown in Table 2, the obtained shaped product had a good surface smoothness, a small shrinkage phenomenon, no curling phenomenon (warpage), and a flat shape (shape preservation), as shown in Table 2. (The moldability was good) and the porous state was uniform.

(Example 5) Except that the shaped article was immersed in an aqueous solution tank at an immersion temperature of 10 ° C and the concentration of dimethylformamide (DMF) was 20% by weight, discharged into an aqueous solution tank, immersed and coagulated. Is 15 mm under the same conditions as in Example 3.
Was molded.

As shown in Table 2, the obtained shaped product had a good surface smoothness, a small shrinkage phenomenon, no curling phenomenon (warpage), and a flat shape (shape preservation), as shown in Table 2. (The moldability was good) and the porous state was uniform.

(Example 6) Except that the shaped article was immersed in an aqueous solution tank at a temperature of 10 ° C and the concentration of dimethylformamide (DMF) was discharged to an aqueous solution tank having a concentration of 40% by weight, immersed and coagulated. Is 15 mm under the same conditions as in Example 3.
Was molded.

As shown in Table 2, the obtained shaped product had a good surface smoothness, a small shrinkage phenomenon, no curling phenomenon (warpage), and a flat shape (shape preservation), as shown in Table 2. (The moldability was good) and the porous state was uniform.

(Comparative Example 3) The same procedure as in Example 3 was repeated except that the immersion temperature of the shaped article in the aqueous solution tank was changed to 10 ° C.
A 5 mm flat shaped article was molded.

As shown in Table 2, the obtained shaped article had irregularities on the surface, a shrinkage phenomenon was observed, a curling phenomenon (warpage) was observed, and the flat shape retention was poor. It was in an incompletely porous state.

[0076]

[Table 2]

(3) About Addition and Mixing of Thickener (Example 7) Dimethylformamide (DMF) 20% by weight, polyurethane resin (polyester urethane elastomer (manufactured by Dainichi Seika)) 30% by weight, water-soluble polymer 30% by weight of polyvinyl alcohol (PVA)
15% by weight of carboxymethyl cellulose (CMC),
3% by weight of silica as a thickener was added, and 2% by weight of sodium dioctyl sulfosuccinate as a surfactant was added and kneaded to form a mixture.

This mixture was kneaded with a rotary kneader for 20 minutes, and the temperature of the die discharge portion was set to 10 ° C. by using a cooling type single screw extruder. It was discharged into an aqueous solution tank containing water, immersed and solidified.

Then, it was placed in an aqueous solution tank (extraction tank) containing water at a temperature of 40 ° C., left for 3 hours, and dried in an oven at 60 ° C. for 4 hours to obtain a shaped product.

The surface smoothness, shrinkage state, curling state (warpage), shape-retaining property (plate shape), and porous state of the thus obtained shaped article were observed.

As a result, as shown in Table 3, the obtained shaped product had a good surface smoothness, a small shrinkage phenomenon, no curling phenomenon (warpage), and a flat shape (good shape preservability). ), The porous state was also uniform.

(Embodiment 8) The temperature of the die discharge portion is set to 0 ° C.
A 15 mm flat shaped article was molded under the same conditions as in Example 7 except that the conditions were changed to.

As shown in Table 3, the obtained shaped article had good surface smoothness, a small shrinkage phenomenon, no curling phenomenon (warpage), and a flat shape (shape preservation), as shown in Table 3. (The moldability was good) and the porous state was uniform.

(Comparative Example 4) Silica as a thickener was added to the mixture, and carboxymethyl cellulose (CM
A 15 mm flat molded article was molded under the same conditions as in Example 7 except that C) was changed to 18% by weight.

As shown in Table 3, the obtained shaped product had irregularities on the surface, exhibited a large shrinkage phenomenon,
A curling phenomenon (warpage) was also observed, the shape retention of the flat plate was poor, and the plate was in an incomplete porous state.

[0086]

[Table 3]

[0087]

According to the method for producing a urethane porous body according to the first aspect of the present invention, as specifically described above with reference to one embodiment, the urethane porous body can be produced by a wet solidification method. A polyurethane resin is dissolved in dimethylformamide, and a water-soluble polymer and a surfactant are added and kneaded to form a mixture. The mixture is discharged from a molding die of an extruder to a temperature at which the mixture can be shaped. Then, shaping without extrusion from a molding die, immersing the shaped mixture in an aqueous solution, and coagulating, so as to dissolve and remove the water-soluble polymer, cooling to a temperature at which it can be shaped By extruding from a forming die, it is possible to form a three-dimensional shape, and to obtain a porous body while shaping by a wet solidification method.

As a result, a product shaped into a three-dimensional shape by the wet coagulation method can be formed, a porous body having uniform and dense cells without surface roughness can be obtained, and a urethane porous body can be obtained. A cushion material, a sponge for cosmetics, a roll for OA equipment, a conductive roll, a conductive cushion, and the like can be formed.

According to the method for producing a urethane porous body according to the second aspect of the present invention, a thickener is added to the mixture, and the mixture is discharged at a temperature of 0 to 15 at a molding die portion of an extruder. ° C, so the cooling temperature can be increased by adding a thickener to the mixture, and the porous body can be formed more easily while shaping by the wet coagulation method. The molding can be performed without the need for a special cooling facility, and the temperature is close to room temperature, so that the temperature can be easily adjusted and the quality of the product can be stabilized.

Further, according to the method for producing a urethane porous body according to the third aspect of the present invention, since the aqueous solution in which the shaped mixture is immersed has a water temperature of 20 to 60 ° C., It is possible to efficiently dissolve and elute the water-soluble polymer described above, and to obtain a porous body having uniform and dense cells and a porous body excellent in cushioning property and the like.

Further, according to the method for producing a urethane porous body according to claim 4 of the present invention, the aqueous solution is used for 10 to 50 times.
% Dimethylformamide aqueous solution, so that the dissolution and elution of the water-soluble polymer is promoted, and an excellent porous body can be obtained. Even if the aqueous solution temperature is lower than 20 ° C., a uniform and dense cell can be obtained. It is easy to obtain a porous body having the same, and a porous body having excellent cushioning properties and the like can be obtained.

Continued on the front page F-term (reference) 4F074 AA02 AA42 AA78 AA81 AC32 AD15 AG20 BC02 BC04 BC05 CB03 CB17 CB27 CC05X CC22X CC32X CC32Y CC37X CC61 DA22 DA23 DA24 DA33 DA45 DA47 4F207 AA31 AB10 AB19 AG20 AR06 KA01 KM11 AB04 KA54 AB052 AE053 BC064 BE022 CH022 CK021 CK024 CL004 CP033 DJ017 DJ057 EH046 EV236 FD313 FD316 FD334 FD337 GC00 GM00 GQ00 HA05

Claims (4)

[Claims] When producing a urethane porous body by a wet coagulation method, a polyurethane resin is dissolved in dimethylformamide, and a water-soluble polymer and a surfactant are added and kneaded to form a mixture. The mixture discharge temperature of the portion is cooled to a temperature at which the mixture can be shaped, and shaped by extrusion from a molding die, and the shaped mixture is immersed in an aqueous solution and solidified, and the water-soluble polymer is solidified. A method for producing a urethane porous body, comprising: 2. The urethane porous body according to claim 1, wherein a thickener is added to and mixed with the mixture, and the mixture is discharged at a molding die portion of an extruder at a temperature of 0 to 15 ° C. Method. 3. The method for producing a urethane porous body according to claim 1, wherein the aqueous solution in which the shaped mixture is immersed has a water temperature of 20 to 60 ° C. 4. The method according to claim 1, wherein the aqueous solution is a 10-50% aqueous solution of dimethylformamide.
4. The method for producing a urethane porous body according to any one of items 1 to 3.