JP3305358B2 - Method for producing porous sheet material and sheet - Google Patents

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 polyurethane porous sheet material for wet film formation and a polyurethane porous sheet material.

[0002]

2. Description of the Related Art A method for producing a polyurethane porous sheet material in which a polyurethane resin obtained by reacting an aliphatic polyisocyanate and / or an alicyclic polyisocyanate with an polyol as an essential component of an organic polyisocyanate is wet-formed by a wet coagulation method. Is well known.

[0003] However, the polyurethane resin described above has a problem that the wet film forming property is poor and the texture becomes very hard. Therefore, it is difficult to produce a porous sheet material that can be used as it is. Can not.

Therefore, conventionally, a polyurethane porous sheet material formed by wet film-forming using a cellulose derivative such as cellulose acetate butyrate (CAB) or cellulose acetate propionate as a film-forming aid on a polyurethane resin has been produced. I have.

[0005]

However, even when a cellulose derivative is used in combination, the wet film-forming property is still insufficient, and there is no effect of maintaining a soft texture. Owing to the poor affinity for the compound, the preparation liquid is separated into a polyurethane main component phase and a cellulose derivative main component phase, and there is a disadvantage that an excellent porous sheet material cannot be stably manufactured.

Accordingly, there is a need for a film-forming aid capable of forming a porous sheet material which is excellent in wet film-forming properties, stable and excellent in texture.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies in view of the above-mentioned situation. As a result, when a polyurea resin is used as a film-forming aid, a polyurethane porous film having excellent wet-film forming properties and excellent stability is obtained. The inventors have found that a qualitative sheet material can be obtained, and have completed the present invention.

That is, the present invention relates to a polyurethane for forming a wet film by a wet coagulation method using a polyurethane resin obtained by reacting an aliphatic polyisocyanate and / or an alicyclic polyisocyanate as an essential component of an organic polyisocyanate with a polyol together with a film forming aid. In the method for producing a porous sheet material, a method for producing a polyurethane porous sheet material, wherein a polyurea resin is used as the film-forming auxiliary, and polycarbonate diol, dicyclohexylmethane diisocyanate, and cyclocyclohexylmethanediamine. The present invention provides a porous sheet material having, as an essential layer, a synthetic leather layer made of a polyurethane resin obtained by reacting the above.

The present invention is characterized in that a polyurea resin is used as a film-forming aid at the time of wet film formation. As the wet film formation method itself, any conventional and commonly used method can be adopted. An example of the process for producing the porous sheet material of the present invention will be described below, but it is needless to say that the present invention is not limited to this. First, an organic solvent solution of a polyurethane resin containing a polyurea resin is impregnated and / or applied to a fibrous substrate or applied to a plastic film substrate or the like. The solid is immersed in a solvent that does not dissolve (hereinafter referred to as a coagulating liquid) to coagulate the polyurethane resin to form a porous material, and then, if necessary, completely remove the organic solvent remaining in the porous material and heat the resultant. Drying gives a porous sheet material. At this time, a solvent containing water as a main component is used as the coagulating liquid, and a hydrophilic organic solvent arbitrarily miscible with water is used as a solvent for the polyurethane resin.

According to the findings of the present inventors, surprisingly, in such a wet film formation, when a polyurea resin which is a reaction product of an organic polyisocyanate and an organic polyamine and / or water is used in combination, the wet film formation is improved. The film forming property can be improved, and particularly, the polyurea resin dispersed in the polyurethane resin preparation liquid can give the polyurethane resin an extremely excellent wet film forming property. In addition, the polyurea resin has excellent affinity with the polyurethane resin by having a repeating unit similar to the polyurethane resin. It is considered possible.

In the present invention, the polyurethane resin which is obtained by reacting an aliphatic polyisocyanate and / or an alicyclic polyisocyanate with a polyol as an essential component of an organic polyisocyanate, for example, has a high molecular weight having active hydrogen. A polyurethane resin obtained by reacting a polyol, a low molecular weight polyol having active hydrogen (a so-called chain extender), an organic polyisocyanate containing an aliphatic polyisocyanate and / or an alicyclic polyisocyanate as an essential component.

As a method for producing the polyurethane resin, for example, a polymerization reaction is carried out beforehand in the absence of a solvent and, if necessary, in the presence of a catalyst, and this is dissolved in an organic solvent, or the polymerization reaction is carried out in an organic solvent. Method and the like.

As the high-molecular-weight polyol having active hydrogen in producing the polyurethane resin, diols are preferable, and any known and commonly used polyols can be used, but those having an average molecular weight of 500 to 8,000 are preferable. For example, polyethylene adipate glycol, polyethylene butylene adipate glycol, polypropylene adipate glycol, polybutylene adipate glycol, polydiethylene butylene adipate glycol, polyhexamethylene adipate glycol, polyethylene succinate glycol, polypropylene azelate glycol, polyethylene butylene sebacate glycol, polybutylene Ethylene glycol such as terephthalate glycol,
Diethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, hexamethylene glycol, octamethylene glycol, bis (hydroxymethyl) cyclohexane, 2,2-bis (4,4-
Condensed polyester diol of one or more low molecular weight glycols such as dihydroxyphenyl) propane and one or more dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, and isophthalic acid Polycaprolactone diol; polyalkylene ether polyols such as polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol, polyethylene tetramethylene ether glycol, polyhexamethylene ether glycol; and polymer diols such as polyamide diol, polyamide polyester diol, and polycarbonate diol. ;

[0014]

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[0015]

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[0016]

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(In the above compound, ph represents a phenyl group, m,
n is an integer of 5 to 70, which may be the same or different. And the like, and these may be used alone or in combination of two or more.

Examples of low molecular weight polyols having active hydrogen (so-called chain extenders) include ethylenediamine, propylenediamine, isophoronediamine, cyclohexanediamine, dicyclohexylmethanediamine, phenylenediamine, diaminodiphenylmethane, diaminodicyclohexylmethane, and 2,2-bis. (4,4-diamino-cyclohexyl) propane, t-butylamine, hydrazine, organic amines such as dimethylhydrazine, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, neopentyl glycol,
Hexamethylene glycol, octamethylene glycol, bis (hydroxymethyl) cyclohexane, 2,2-
One or more glycols such as bis (4,4-dihydroxyphenyl) propane are used.

As the organic polyisocyanate, essential components of aliphatic and / or alicyclic polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dicyclohexyldimethyl. One or more of methane diisocyanate and the like may be used, and one or more of aromatic diisocyanates such as diphenylmethane diisocyanate, tolylene diisocyanate, and xylylene diisocyanate may be used in combination.

In order to obtain a polyurethane resin from these active hydrogen-containing compounds and an organic polyisocyanate, it is easy to react in an organic solvent in the presence of a catalyst if necessary. The reaction conditions at this time are not particularly limited, but are usually 20 to 150 ° C. for 0.5 to 12 hours. Examples of the catalyst include nitrogen-containing compounds such as triethylamine, toluethylenediamine, and morpholine; metal salts such as potassium acetate, zinc stearate, and tin octylate; and organic metal compounds such as dibutyltin dilaurate. If necessary, as a polymerization reaction terminator, for example, monohydric alcohols such as methanol, butanol and cyclohexanol, dibutylamine and the like can be used.

According to the findings of the present inventors, polyurethanes are required to be used in applications where extremely severe performance requiring light resistance at high temperatures is required regardless of the presence or absence of a film-forming auxiliary described in detail later. As the resin, it was found that a polyurethane resin obtained by reacting polycarbonate diol, dicyclohexylmethane diisocyanate, and dicyclohexylmethanediamine was particularly excellent.

Examples of the solvent for the polyurethane resin include one or more of dimethylformamide (DMF), dimethylsulfoxide, dioxane, acetone and the like, and DMF is most preferred.

As the organic polyisocyanate and the organic polyamine used in the polyurea resin of the present invention, for example, the organic polyisocyanate and the organic polyamine used in the polyurethane resin can be used. And / or alicyclic groups are preferred.

As the polyurea resin used in applications requiring extremely severe performance requiring light resistance at high temperatures as described above, a polyurethane resin obtained by reacting dicyclohexylmethane diisocyanate with dicyclohexylmethanediamine is used. Especially excellent.

The polyurea resin has an equivalent ratio of organic polyisocyanate / organic polyamine of 1.0 / 0.6 to 1.0.
/1.0 can be easily obtained by reacting in the presence of a catalyst if necessary. The reaction conditions at this time are not particularly limited, but are usually 20 to 150 ° C.
0.5 to 12 hours. As the catalyst, for example, any of those mentioned in the polymerization reaction of the polyurethane resin can be used. In addition to adding the polyurea resin solution obtained in this manner to a polyurethane resin solution polymerized by another operation to prepare a preparation solution, a polymerization reaction of the polyurea resin is continuously performed after the polymerization reaction of the polyurethane resin solution. The present invention also includes a method for preparing a polyurethane resin solution containing a polyurea resin. When the latter method is adopted, only one reaction vessel is required, so that it is not necessary to mix separately manufactured products. In some cases, the compatibility may be better than that of a composition obtained by mixing separately manufactured components.

As the polyurea resin used in the present invention, those having an average molecular weight of 1,000 or more and 100,000 or less are particularly preferred. Those having this range can be uniformly and sufficiently dispersed in the organic solvent of the polyurethane resin, and can impart sufficient particularly excellent wet film forming properties. Moreover, the polymerization reaction for obtaining the polyurea resin itself is very easy.

The amount of the polyurea resin solids used in the present invention is usually 30 parts by weight or less, preferably 0.5 to 25 parts by weight, per 100 parts by weight of the polyurethane resin solids. Within this range, the wet film-forming properties are good, and the resulting polyurethane porous sheet material does not easily exhibit the hardness of the polyurea resin itself, and has good practical flexibility.

As the fibrous base material and the plastic film base material to be impregnated and / or coated used in the present invention, any known and commonly used ones can be used. For example, as the fibrous base material, a fiber aggregate in which fibers are formed into a non-woven fabric, a woven fabric, a knitted fabric, or the like, or a fiber aggregate in which fibers are bonded with an elastic polymer, The fibers used in the body include ordinary fibers, for example, natural fibers such as cotton, hemp, wool, etc., regenerated or semi-synthetic fibers such as rayon and acetate, and synthetic fibers such as nylon, polyester, polyacrylonitrile, vinylon, and polyolefin. In addition, a single spun fiber or a mixed spun fiber (including a conjugate spun fiber) may be used. Other base materials include paper, release paper, plastic films such as polyester and polyolefin, and metal foils such as aluminum.
The sheet material obtained according to the use may be peeled off from the substrate and used.

In the production method of the present invention, a porous sheet is obtained by subjecting an organic solvent solution of a polyurethane resin containing a polyurea resin to a usual wet film formation treatment. At this time, the resin solution contains If necessary, colorants, antioxidants, ultraviolet absorbers, flame retardants, water / oil repellents, deodorants, antistatic agents, fragrances, release agents, lubricants, fillers, coagulation stabilizers, foaming agents, etc. Additives can be added alone or in combination of two or more. Further, if necessary, the weight of synthetic rubber, polyvinyl chloride or vinyl chloride copolymer, vinyl acetate or vinyl acetate copolymer, amino acid resin, polyurethane / polyamino acid block copolymer, polyester elastomer, polyamide elastomer, polyamide, etc. Coalescence can be added.

Thus, the polyurethane porous sheet material obtained by the production method of the present invention is excellent in wet film forming property and stable, and further, the urethane porous layer has a uniform cell structure. For this reason, grinding also has a feature of giving a so-called suede-like appearance by grinding at least one surface of the sheet material.

The porous sheet material obtained by the production method of the present invention can be used, for example, by itself or by laminating it with a known material. The porous sheet material thus obtained is, for example, furniture such as shoes, bags, and chairs,
Any of them can be used in known and common fields such as vehicle interior materials such as automobile seats.

[0032]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Parts and percentages in Examples and Comparative Examples are on a weight basis unless otherwise specified. The meanings of the symbols described below are as follows. IPDI: isophorone diisocyanate H ₁₂ MDI: dicyclohexylmethane diisocyanate IPDA: isophorone diamine H ₁₂ MDA: dicyclohexyl methane diamine Example 1 <Preparation of polyurethane resin solution> Average molecular weight in a reactor equipped with a stirrer, a reflux condenser and a thermometer. After 2,000 parts of poly (1,6-hexamethylene carbonate) diol (200 parts) and 70 parts of DMF were charged and uniformly dissolved, 56 parts of IPDI and stannous octylate as a reaction catalyst were added thereto. Was added, and the mixture was allowed to react at 80 ° C. for 4 hours. Then, 100 parts of DMF was added and the mixture was cooled. A solution of an isocyanate prepolymer having a solid content of 60% and an isocyanate group equivalent of 1419 was obtained. Obtained. This isocyanate prepolymer solution 28
4 parts with 21 parts of H ₁₂ MDA, 652 parts of DMF,.
The same colorless transparent viscous solution (PU-1) having a solid content of 20% was charged in a similar reactor charged with 2 parts of a reaction terminator (dibutylamine) and reacted at 35 ° C. for 2 hours.
957 parts were obtained.

<Preparation of Polyurea Resin Solution> In a reactor equipped with a stirrer, a reflux condenser and a thermometer, 561 parts of DM was added.
F, 85 parts of H ₁₂ MDI were charged and uniformly dissolved, and then 55 parts of IPDA were charged so that the H ₁₂ MDI / IPDA had a 1.0 / 1.0 equivalent ratio, and the reaction was carried out at 40 ° C. for 1 hour. Thus, 701 parts of a cloudy polyurea resin solution (UR-1) having a solid content of 20% and an average molecular weight of 80,000 were obtained.

<Manufacture of porous sheet material> A non-woven fabric bed made of polyethylene terephthalate / nylon fiber and entangled with a urethane polymer and having a thickness of 1 mm and a weight of 400 g / m ² (Miracle Cloth DF- Japan in 5
Impregnated with Chrisbon MP-120, an ink chemical product
And ones) as a base material, 200 parts of PU-1, UR-1
30 parts of a paste-like pigment (manufactured by Dainippon Ink and Chemicals, Inc.)
Of the product, Dirac L-1770S) was applied to the substrate at 800 g / m ² , and immersed in a 10% aqueous solution of DMF at 20 ° C. for wet coagulation. Next, it was immersed in warm water at 70 ° C. to perform an excessive solvent removal treatment, squeezed with a squeeze roll, and dried at 120 ° C. to obtain a porous sheet material.

The resulting porous sheet material had a very smooth porous layer on the fibrous base material due to its excellent wet film-forming properties, and also had a soft feel. This porous sheet material could be subjected to various surface design processes, and was very practical. Comparative Example 1 Example 1 except that the polyurea resin (UR-1) was not used.
And a porous sheet material was obtained.

In this case, the wet film-forming property is extremely poor, and the resulting porous sheet material has a completely collapsed porous layer on the fibrous base material, has no flexibility, and is practically usable. I couldn't do anything. Comparative Example 2 CAB was replaced with DMF in place of the polyurea resin (UR-1).
A porous sheet material was obtained in exactly the same manner as in Example 1 except that a solution dissolved so as to have a solid content of 20% was used. The wet film formability was better than Comparative Example 1, but was still insufficient.

In the obtained porous sheet material, the porous layer on the fibrous base material collapsed into an uneven shape, and the flexibility was poor. When producing a porous sheet material, the stability of the composition was also significantly worse than that of Example 1. As a result, the sheet material was completely unusable. Example 2 <Preparation of polyurethane resin solution> In a reactor equipped with a stirrer, a reflux condenser and a thermometer, 200 parts of polybutylene adipate having an average molecular weight of 2,000 and 70 parts of DMF were added.
After mixing and dissolving uniformly, the IPDI 5
6 parts and 0.06 of stannous octoate as a reaction catalyst
And the mixture was reacted at 80 ° C. for 4 hours. Then, 100 parts of DMF was added and cooled, and the solid content was 60%.
A solution of the isocyanate prepolymer having an isocyanate group equivalent of 1419 was obtained. 284 parts of this isocyanate prepolymer solution was added to 21 parts of H ₁₂ MDA, 6 parts.
In a similar reactor charged with 52 parts of DMF and 0.2 parts of a reaction terminator (dibutylamine), the mixture was reacted at 35 ° C. for 2 hours, and the desired colorless transparent viscous solid having a solid content of 20% was obtained. 957 parts of a solution (PU-2) were obtained.

<Preparation of Polyurea Resin Solution> 748 parts of DM was placed in a reactor equipped with a stirrer, a reflux condenser and a thermometer.
F, 100 parts of IPDI was charged and uniformly dissolved, and then 76 parts of H ₁₂ MDA was charged so that the IPDI / H ₁₂ MDA had a 1.0 / 0.80 equivalent ratio, and reacted at 40 ° C. for 1 hour. Then, 12 parts of a reaction terminator (dibutylamine) was added to obtain 936 parts of a cloudy polyurea resin solution (UR-2) having a solid content of 20% and an average molecular weight of 2,000.

<Production of porous sheet material> A polyethylene terephthalate / nylon fiber having a thickness of 0.95
mm, weight of 250 g / m ² non-woven fabric (Daiwa Spinning Products Mira
Curcross DF-5) as the base material, PU-2 200
The base material was immersed in a preparation liquid containing 15 parts of a resin solid content consisting of 40 parts of UR-2 and 80 parts of DMF. Next, the solution was squeezed so that the ratio of the base material to the preparation solution became 100: 600, and then immersed in a 10% aqueous solution of DMF at 20 ° C. for wet solidification. Next, it was immersed in warm water at 70 ° C. to perform an excessive solvent removal treatment, squeezed with a squeeze roll, and dried at 120 ° C. to obtain a porous sheet material.

The obtained porous sheet material has a very smooth surface layer of the fibrous base material due to its excellent wet film formability.
Moreover, the texture was flexible. As described above, Examples 1 to
Table 1 summarizes the results of Comparative Example 2 and Comparative Examples 1 and 2.

[0042]

[Table 1]

Example 3 <Preparation of Polyurethane Resin Solution> In a reactor equipped with a stirrer, a reflux condenser and a thermometer, 200 parts of poly (1,6-hexamethylene carbonate) diol having an average molecular weight of 2,000 and After charging 196 parts of DMF and uniformly dissolving, 39 parts of H ₁₂ MDI and 0.06 parts of stannous octylate as a reaction catalyst were added thereto, and
After the reaction at 4 ° C. for 4 hours, a solution of an isocyanate prepolymer having a solid content of 55% and an isocyanate group equivalent of 4425 was obtained. 186 parts of this isocyanate prepolymer solution are mixed with 36 parts of H ₁₂ MDA, 470 parts of DMF, 0.2 parts of a reaction terminator (dibutylamine).
And reacted at 35 ° C. for 2 hours to obtain 692 parts of a target colorless and transparent viscous solution (PU-3) having a solid content of 20%.

<Preparation of Polyurea Resin Solution> In a reactor equipped with a stirrer, a reflux condenser and a thermometer, 600 parts of DM was added.
F, 84 parts of H ₁₂ MDI were charged and uniformly dissolved, and then 66 parts of H ₁₂ MDA were charged so that the H ₁₂ MDI / H ₁₂ MDA had a 1.0 / 0.98 equivalent ratio, and 40 ° C. At 1
After reacting for 20 hours, the solid content is 20% and the average molecular weight is 20,0.
Thus, 750 parts of a white turbid polyurea resin solution (UR-3) were obtained.

<Production of porous sheet material> 200 parts of PU-3, 2 parts of UR-3, a paste-form blue pigment (Dainichi
This ink chemical product Dailac L-1779S) 2
A 0 part liquid mixture having a resin solid content of 20% was applied to a polyethylene terephthalate film (Lumilar # manufactured by Toray Industries, Inc.).
T-125) at 900 g / m ² ,
% DMF aqueous solution for wet coagulation. Next, it was immersed in warm water at 50 ° C. to perform an excessive solvent removal treatment, squeezed with a squeeze roll, dried at 100 ° C., and then peeled from the polyethylene terephthalate film to obtain a porous sheet material.

The obtained porous sheet material was excellent in wet film-forming properties, was a flexible film without sticking, and was very practical with various surface designs. Example 4 In Example 3, a porous sheet material was manufactured using a preparation liquid obtained by continuously performing a polymerization reaction of a polyurea resin after a polymerization reaction of a urethane resin.

That is, a poly (1,6-hexamethylene carbonate) diol having an average molecular weight of 2,000 was placed in a reactor equipped with a stirrer, a reflux condenser and a thermometer.
After charging 00 parts and 196 parts of DMF and uniformly dissolving, 39 parts of H ₁₂ MDI and 0.06 parts of stannous octylate as a reaction catalyst were added thereto, and the mixture was added at 80 ° C. for 4 hours.
After reacting for an hour, a solution of an isocyanate prepolymer having a solid content of 55% and an isocyanate group equivalent of 4425 is obtained. 186 parts of this isocyanate prepolymer solution are mixed with 36 parts of H ₁₂ MDA, 470 parts of DMF,
Into a similar reactor charged with 0.2 part of a reaction terminator (dibutylamine), reacted at 35 ° C. for 2 hours,
Finish the urethane polymerization reaction. Then continuously H ₁₂ MDI
/ H ₁₂ MDA is 1.0 / 0.98 equivalent ratio,
After 0.78 parts of H ₁₂ MDI is charged and uniformly dissolved, 0.61 part of H ₁₂ MDA is added and reacted at 40 ° C. for 1 hour to obtain a cloudy viscous solution having a solid content of 20%. A paste-like pigment (Dainichi) is added to 200 parts of this viscous solution.
Daikku L-1770S)
To prepare a preparation liquid for producing a porous sheet material. In this method, only one reaction vessel is required, and the trouble of mixing the separately obtained polyurethane resin and polyurea resin can be omitted.

A porous sheet material was obtained by performing the same operation as in Example 1 except that this prepared liquid was used. The obtained porous sheet material was excellent in wet film formability, was a flexible film without sticking, and was very practical with various surface designs.

The results of Examples 3 and 4 are summarized in Table 2.

[0050]

[Table 2]

Example 5 The porous sheet material obtained in Example 3 was added to a conventional cross-linkable curable polyurethane adhesive (Clean product of Dainippon Ink and Chemicals, Inc.).
Subon TA-205, Crisbon NX, Crisbon Ak
(A mixture of the cell HM and a solvent) , and heat-treated, then laminated with a porous polyurethane sheet, and then heat-treated and aged to prepare an automobile seat sheet.

This sheet was cut out to obtain a test piece. Using the porous sheet surface of Example 3 of this test piece, an ultraviolet long life fade meter with a black panel temperature of 83 ± 3 ° C. [Suga Test Machine Co., Ltd. FAL-5H-B type]
A 400-hour high-temperature light resistance test was performed. However, this test piece had almost no discoloration and was extremely excellent in light resistance.

Table 3 shows the results of the high temperature light resistance test. The changes in film thickness and density are the results obtained by using the sheet of Example 3 itself.

[0054]

[Table 3]

[0055]

According to the present invention, since a polyurea resin is used as a film-forming aid during wet film formation of a polyurethane resin, it has better wet film formability and flexibility than conventional production methods. A polyurethane porous sheet material can be obtained.

In the present invention, since a polycarbonate resin is used as the polyurethane resin, polycarbonate diol, dicyclohexylmethane diisocyanate, and dicyclohexylmethanediamine, a porous sheet having excellent light resistance at extremely high temperatures can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08J 9/28 101

Claims (7)

(57) [Claims] 1. Polyurethane porous material which is formed by wet coagulation of a polyurethane resin obtained by reacting an aliphatic polyisocyanate and / or an alicyclic polyisocyanate with a polyol as an essential component of an organic polyisocyanate together with a film forming aid. In a method for manufacturing a sheet material,
A method for producing a polyurethane porous sheet material, wherein a polyurea resin is used as the film forming aid. 2. The polyurea resin has an average molecular weight of 1,000.
2. The method according to claim 1, wherein the amount is at least 100,000. 3. The polyurethane resin according to claim 1, wherein the polyurea resin is substantially compatible with the polyurethane resin and is dispersed without being dissolved in an organic solvent of the polyurethane resin.
The manufacturing method as described. 4. The method according to claim 1, wherein the polyurea resin is a reaction product of an organic polyisocyanate and an organic polyamine and / or water. 5. The method according to claim 1, wherein the amount of the solid content of the polyurea resin is 30 parts by weight or less per 100 parts by weight of the solid content of the polyurethane resin. 6. A porous sheet material having, as an essential layer, a synthetic leather layer made of a polyurethane resin obtained by reacting polycarbonate diol, dicyclohexylmethane diisocyanate, and cyclocyclohexylmethanediamine. 7. The porous sheet material according to claim 6, wherein the polyurethane resin further contains a polyurea resin obtained by reacting dicyclohexylmethane diisocyanate with cyclohexylmethanediamine.