JP2003119314A - Porous sheet material and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous sheet material of a polycarbonate-based polyurethane resin having uniform pores, good texture, and excellent hydrolysis resistance and weather resistance. Aim. SOLUTION: A porous sheet material obtained by applying a solution of a polyurethane resin (D) comprising a polymer diol (A), an organic diisocyanate (B) and, if necessary, a chain extender (C) to a substrate and by a wet film forming method. Wherein (A) is a polymer diol comprising a mixed diol of a polycarbonate diol (a1) and a polyester diol (a2), and (a1) is 1,4-butanediol and another alkane having 4 to 6 carbon atoms. Consisting of at least one diol, and based on the total number of moles of the diol, the diol contains 50 to 90 mol% of 1,4-butanediol;
And a copolymerized polycarbonate diol having a number average molecular weight of 500 to 5,000, and a solidification value of (D) of 7 to
A porous sheet material characterized by the number 14 is used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a porous sheet material. More specifically, the present invention relates to a porous sheet material obtained by applying a urethane resin to a substrate and performing a wet film formation method.

[0002]

2. Description of the Related Art Conventionally, it has been considered preferable to use a polyurethane resin solution containing a polycarbonate diol in order to improve the hydrolysis resistance and weather resistance of a porous sheet material. However, when a polycarbonate-based polyurethane resin solution is used for wet coagulation, the coagulation force is so large that the film surface rapidly coagulates, and the film of dense pores formed on the surface suppresses the diffusion of the solvent into the coagulating liquid. Since it has a structure in which huge pores are formed inside, it is difficult to obtain a porous sheet having uniform pores. Therefore, various studies have been made to solve this problem.

For example, as disclosed in Japanese Unexamined Patent Publication No. 5-186631, a method of wet coagulation in a coagulation bath at 30 to 50 ° C. is known.

[0004]

However, it is hard to say that the method of wet coagulation at a constant coagulation bath temperature as described above has obtained a porous sheet having sufficiently uniform pores. The present invention is to provide a porous sheet of a polycarbonate-based polyurethane resin having uniform pores and having a good texture.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found a porous sheet of a polycarbonate polyurethane resin having uniform pores and having a good texture. That is, the present invention provides a porous sheet obtained by a wet film forming method in which a solution of a polyurethane resin (D) containing a polymer diol (A), an organic diisocyanate (B) and optionally a chain extender (C) is applied to a substrate. In the material, (A) is a polymer diol composed of a mixed diol of polycarbonate diol (a1) and polyester diol (a2), and (a)
1) is 1,4-butanediol and other 4- to 4-carbons
6 or more of the alkane diols of No. 6, and the diol contains 50 to 90 mol% of 1,4-butanediol based on the total number of moles of the diol, and the number average molecular weight of the diol is 500 to 5,000. A porous sheet material characterized by being a copolycarbonate diol and having a coagulation number of (D) of 7 to 14, and a method for producing the same.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The polymeric diol (A) used in the present invention comprises a mixed diol of a polycarbonate diol (a1) and a polyester diol (a2). (A
1) is a polycarbonate diol obtained by reacting a low molecular diol with a carbonic acid diester of a lower alcohol (such as methanol). Further, (a1) is 1,4-
It comprises at least one of butanediol and other alkanediol having 4 to 6 carbon atoms, and the diol is 1,4-butanediol based on the total number of moles of the diol.
0 to 90 mol% and a number average molecular weight of 500 to
It is 5,000 copolymerized polycarbonate diols.
Hereinafter, the number average molecular weight of (a1) is determined from the hydroxyl value.
Further, the number average molecular weights of (a2), (A) and (C) are similarly obtained. The hydroxyl value is JIS K 0.
070-1992 (potentiometric titration method).

Examples of the alkanediol having 4 to 6 carbon atoms include 1,5-pentanediol and 2-methyl-
1,3-propanediol, neopentyl glycol,
1,6-hexanediol, 3-methyl-1,5-pentanediol and 2-ethyl-1,3-propanediol are mentioned, and preferred among them are 1,5-pentanediol and 1,6- Hexanediol. The diol constituting (a1) is usually 1,9-butanediol in an amount of 50 to 9 based on the total number of moles of the diol.
0 mol%, preferably 55 to 90 mol%, more preferably 60 to 90 mol%. 1,4-in the diol
When the content of butanediol is less than 50 mol%, the hydrophilicity becomes insufficient, so the uniformity of the pore structure of the resulting porous sheet is insufficient, and when it exceeds 90 mol%, the strength and physical properties become high. If it is too large, the texture of the resulting porous sheet becomes hard, which is not preferable. Examples of specific combinations of diols constituting (a1) and their molar ratios are:
1,4-butanediol / 1,6 hexanediol = 7
0/30, 90/10 and the like.

The number average molecular weight of (a1) is usually 500 to
It is 5,000, preferably 700 to 4,500, more preferably 1,000 to 4,000. That is, (a
The number average molecular weight of 1) is usually 500 or more, preferably 7
It is 00 or more, more preferably 1,000 or more, usually 5,000 or less, preferably 4,500 or less, more preferably 4,000 or less. When the number average molecular weight of (a1) is less than 500, the resulting porous sheet has a hard texture, and when it exceeds 5,000, the strength and physical properties of the polyurethane resin are insufficient, which is not preferable.

Examples of the method for producing (a1) include, for example, US Pat. No. 4,013,702, US Pat. No. 4,105,641 and Schnell, Polymer Reviews, Volume 9, pages 9-20 (1964). ) And the like.

As the polyester diol (a2),
For example, a polyester diol synthesized from at least one kind of saturated aliphatic diol having 2 to 6 carbon atoms and at least one kind of saturated aliphatic dicarboxylic acid having 6 to 10 carbon atoms can be mentioned. Examples of the saturated aliphatic diol having 2 to 6 carbon atoms include ethylene glycol, diethylene glycol, 1,
2-propylene glycol, 1,4-butanediol,
Neopentyl glycol, 1,6-hexanediol,
3-Methyl-1,5-pentanediol may be mentioned, with preference given to ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,4-butanediol, and neopentyl glycol. Examples of the saturated aliphatic dicarboxylic acid having 6 to 10 carbon atoms include adipic acid, azelaic acid and sebacic acid, and adipic acid is preferable. Preferred examples of (a2) are polyester diol synthesized from neopentyl glycol and adipic acid, polyester diol synthesized from 1,4-butanediol and adipic acid, polyester diol synthesized from ethylene glycol and adipic acid, It is a polyester diol synthesized from diethylene glycol and adipic acid.

The number average molecular weight of the polyester diol (a2) is preferably 500 to 5,000, more preferably 700 to 4,500, and most preferably 1,000 to 4,000 from the viewpoint of strength and physical properties. .

The method for producing (a2) may be the same as the conventional method, and the low molecular weight diol and dicarboxylic acid may be reacted under ordinary reaction conditions so as to form a terminal hydroxyl group.

The polyurethane resin (D) usually has a coagulation number of 7
-14, preferably 8-13, more preferably 9-1
It is 3. That is, the coagulation number of the polyurethane resin (D) is usually 7 or more, preferably 8 or more, more preferably 9 or more.
It is above, usually 14 or less, preferably 13 or less. When the coagulation number of (D) is less than 7, the gelling rate is high and the uniformity of the fine pore structure of the obtained porous sheet material is insufficient. On the other hand, if the coagulation number of (D) exceeds 14, the coagulation rate becomes extremely slow and it is not practical, which is not preferable. The coagulation number means that a 1% by weight solution of polyurethane resin in dimethylformamide is prepared, and 100 g of this solution is added to 25
While adjusting the temperature to ℃, stirring with a stirrer, 25
C. Water is added dropwise. At this time, the amount of dripping water required to reach the point where the polyurethane resin gelled and became cloudy (ml)
That is.

The polymer diol (A) is composed of a mixed diol of polycarbonate diol (a1) and polyester diol (a2), and the weight ratio of (a1) and (a2) is 40:60 or more from the viewpoint of hydrolysis resistance. It is preferably 50:50 or more, more preferably 60:40 or more, more preferably 90:10 or less, and further preferably 80:20 or less from the viewpoint of the texture of the porous sheet. , Most preferably 70: 3
It is 0 or less. The number average molecular weight of the polymeric diol (A) is preferably 500 to 5,000, more preferably 700 to 4,500, and most preferably 1,000 to 4,000 from the viewpoint of strength and physical properties.

As the organic diisocyanate (B), those conventionally used in the production of polyurethane can be used. Such organic diisocyanates include aromatic diisocyanates having 6 to 20 carbon atoms (excluding carbon in NCO group, the same applies hereinafter), aliphatic diisocyanates having 2 to 18 carbon atoms, and alicyclic diisocyanates having 4 to 15 carbon atoms. ,
Aroaliphatic diisocyanates having 8 to 15 carbon atoms, modified products of these diisocyanates (carbodiimide modified products,
Urethane modified products, uretdione modified products, etc.) and mixtures of two or more thereof.

Specific examples of the above aromatic diisocyanate include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate, 2,4'- and / or 4,
4'-diphenylmethane diisocyanate (hereinafter MDI
Abbreviated), 4,4′-diisocyanatobiphenyl, 3,
3'-Dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate and the like can be mentioned.

Specific examples of the above aliphatic diisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate and 2,6-diisocyanatomethyl carboxy. Examples thereof include proate, bis (2-isocyanatoethyl) carbonate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

Specific examples of the alicyclic diisocyanate include isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate and bis (2-isocyanatoethyl) -4-cyclohexylene-. 1,2-dicarboxylate, 2,5-
And / or 2,6-norbornane diisocyanate and the like.

Specific examples of the araliphatic diisocyanate include m- and / or p-xylylene diisocyanate and α, α, α ', α'-tetramethylxylylene diisocyanate.

Of these, preferred are aromatic diisocyanates, and particularly preferred is MDI.

As the chain extender (C), a low molecular weight diol (eg ethylene glycol, propylene glycol,
1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, etc.), alicyclic diol [1,4-bis (hydroxymethyl) cyclohexane, etc.], aromatic diol [1,4-bis (hydroxyethyl) benzene, etc.], aliphatic diamine (ethylenediamine, etc.), alicyclic diamine (isophoronediamine, etc.), aromatic diamine (4,4′-diaminodiphenylmethane, etc.), aromatic aliphatic diamine (Xylylenediamine, etc.) Alkanolamine (Ethanolamine, etc.),
Examples include hydrazine, dihydrazide (such as adipic acid dihydrazide), and the like, and mixtures of two or more thereof. Of these, preferred are low molecular weight diols, and more preferred are ethylene glycol and 1,4-
Butanediol, 1,6-hexanediol and a mixture of two or more thereof. The molecular weight of the above (C) is 2
50 or less is preferable.

In the production of the polyurethane resin solution in the present invention, the equivalent ratio of the organic diisocyanate (B) and the active hydrogen group-containing compound consisting of the polymer diol (A) and the chain extender (C) used if necessary is (0.95 to 1.1): 1 is preferable, and (0.97 to 1.05): 1 is more preferable. When the equivalent ratio is outside the above range, it is difficult to produce a polyurethane resin having the number average molecular weight shown below.

The equivalent ratio of the polymer diol (A) and the chain extender (C) is preferably 1: 0 to 10, more preferably 1: 1 to 5.

The number average molecular weight of the polyurethane resin (D) is preferably 20,000 or more from the viewpoint of resin strength, and 500,000 or less from the viewpoint of viscosity stability. More preferably, it is 40,000-150,000. That is, the number average molecular weight of the polyurethane resin (D) is 2
It is preferably 10,000 or more, and more preferably 40,0.
It is 00 or more, preferably 500,000 or less, and more preferably 150,000 or less. The number average molecular weight of (D) is measured by gel permeation chromatography (hereinafter referred to as GPC), for example, under the following conditions. Instrument: Tosoh Corp. HLC-8220 Column: Tosoh TSKgel α-M Solvent: DMF Temperature: 40 ° C. Calibration: Polystyrene

The content of nitrogen derived from (B) in (D) is 2 to 4.5% by weight based on the weight of (D).
Is preferable, and 2.5 to 4% by weight is more preferable. Within this range, a porous sheet having good wet film-forming property and good texture can be obtained. That is, (D)
The content of nitrogen derived from (B) in is (D)
2% by weight or more based on the weight of
2.5 wt% or more is more preferable, 4.5 wt% or less is preferable, and 4 wt% or less is further preferable.

The polyurethane resin (D) may be produced by an ordinary method, for example, a one-shot method in which a polymer diol (A), an organic diisocyanate (B) and optionally a chain extender (C) are simultaneously reacted. Alternatively, there may be mentioned a prepolymer method in which (A) and (B) are first reacted to obtain a polyurethane prepolymer and then (C) is further reacted. The reaction temperature may be the same as the temperature usually adopted in the polyurethane-forming reaction, preferably 20 to 160.
C., more preferably 40 to 80.degree. If necessary, a polymerization terminator such as monoalcohol (methanol, butanol, cyclohexanol, etc.), monoamine (methylamine, butylamine, cyclohexylamine, etc.) can be used. In order to accelerate the reaction, it is possible to use a catalyst usually used for polyurethane reaction [eg, amine-based catalyst (triethylamine, triethylenediamine, etc.), tin-based catalyst (dibutyltin dilaurate, dioctyltin dilaurate, etc.)] if necessary. it can. The amount of the catalyst used is preferably 1% by weight or less based on the polyurethane resin.

The production of the polyurethane resin solution is carried out in the presence or absence of an organic solvent, and when it is carried out in the absence of the organic solvent, the organic solvent is added later or once a solid resin is produced, For example, a method of dissolving in a solvent can be performed. When carrying out in the presence of a solvent, those listed below can be used as a suitable solvent.

Examples of the organic solvent used for dissolving the polyurethane resin (D) in the present invention include amide solvents [N, N-dimethylformamide (hereinafter abbreviated as DMF), N, N-dimethylacetamide (hereinafter DMAC). , N-methylpyrrolidone, etc.]; sulfoxide-based solvent [dimethyl sulfoxide (hereinafter abbreviated as DMSO), etc.]; ketone-based solvent (methyl ethyl ketone, etc.); ether-based solvent (dioxane, THF, etc.); ester-based solvent ( Methyl acetate, ethyl acetate, butyl acetate, etc.); aromatic solvents (toluene, xylene, etc.), etc., and mixtures of two or more thereof. Among these, preferred are amide solvents, and particularly preferred is DMF.

The resin concentration of (D) is preferably 10% by weight or more from the viewpoint of resin strength, and 5 from the viewpoint of viscosity stability.
It is preferably 0% by weight or less. More preferably 12 to 30
% By weight.

If necessary, the polyurethane resin solution obtained by the method of the present invention contains a coloring agent such as titanium oxide, an ultraviolet absorber (benzophenone type, benzotriazole type, etc.) and an antioxidant [4,4'-butylidene-bis ( Three
-Methyl-6-1-butylphenol) and other hindered phenols; triphenylphosphite, trichloroethylphosphite and other organic phosphites, etc.], various stabilizers, inorganic fillers (calcium carbonate, etc.), and known coagulation adjustments. Agent [Higher alcohol (Japanese Patent Publication No. 42-2
2719), a crystalline organic compound (Japanese Patent Publication No. 56-4).
1652), hydrophobic nonionic surfactants (JP-B-45-39634 and JP-B-45-39635)], and the like. The total addition amount (content) of each of these additives is preferably 5% by weight or less with respect to the polyurethane resin.

The substrate used in the production of the porous sheet material according to the production method of the present invention is not particularly limited, and various substrates can be used, such as natural or synthetic fibers (wool, cotton, polyamide, polyester, rayon, etc.) A woven fabric composed of two or more kinds of these mixed fibers),
Examples thereof include knitted cloth, non-woven cloth, felt, raised cloth and paper, plastic film, metal plate, glass plate and the like. In the present invention, a sheet material may be peeled off from these substrates,
It is also possible to use a sheet material integrated with the substrate.

The polyurethane resin solution (D) of the present invention is
Even when a woven fabric, knitted fabric, non-woven fabric, or the like that easily penetrates into the substrate is used as the substrate, a porous sheet having uniform pores and a good texture can be obtained without pretreatment of the substrate.

When the polyurethane resin solution obtained by the production method of the present invention is applied to a substrate and wet-processed, the application (coating and / or impregnation) of the solution and the wet-process are carried out by a conventional wet-process method, for example, US Pat. 3284274
Nos. 10 to 11 (a), (b), (c),
It can be performed by the method (d). Examples of the liquid (non-solvent) used in the wet treatment include water, ethylene glycol, glycerin, ethylene glycol monoethyl ether, hydroxyethyl acetate and a mixture thereof. Water is preferred. As the coagulation bath, the non-solvent alone may be used, or a mixed bath of the non-solvent and a solvent (DMF, DMSO, etc.) may be used. Alternatively, a method of solidifying with water or steam, or a method of partially solidifying with steam and then immersing in a coagulating bath may be used. You may add a nonsolvent to a polyurethane resin solution, apply as a colloidal dispersion to a substrate, and immerse it in a coagulation bath. The temperature of the coagulation bath is preferably 20 to 60 ° C.

After the wet treatment, desolvation, washing (implemented with water, methanol, etc.) and drying are carried out by usual methods. It is also possible to use anionic, nonionic or cationic or amphoteric surfactants for promoting solvent removal. Further, the crosslinking treatment can be carried out by the method described in British Patent No. 1168872.

The porous sheet obtained from the present invention can be used as it is, but from the viewpoint of imparting various characteristics, a polyurethane resin solution or another polymer (for example, vinyl chloride or cellulose resin) is further added thereto. Etc.) Used as a laminate obtained by coating a solution or emulsion, or by laminating the release solution after coating the polymer solution or emulsion separately coated on the release paper with the coating film obtained by drying. It is also possible.

The porous sheet material of the present invention has excellent wet film-forming property, hydrolysis resistance and weather resistance, and also has uniform pores, so that it is also excellent in texture. It is also excellent in physical properties such as tensile strength, elongation, and flex resistance. Therefore, the porous sheet material obtained by the production method of the present invention is extremely useful as a leather substitute for a wide range of applications such as shoes, bags, clothing, furniture and vehicle seats.

[0037]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Parts in the examples and comparative examples are parts by weight, and% is% by weight.

The viscosity, the number average molecular weight of the resin, the evaluation of the porous sheet and the hydrolysis resistance in the test examples were carried out according to the following methods. (1) 5 samples of viscosity sample (polyurethane resin solution) in a constant temperature water bath at 20 ° C
After adjusting the temperature for a certain period of time, B-type viscometer [BH manufactured by Toki Sangyo Co.
Type viscometer], NO. The measurement was performed at 7 rotors and a rotation speed of 20 rpm. (2) Number average molecular weight Tosoh Co., Ltd. HLC-8220 (column: Tosoh T
The molecular weight was measured using SKgel α-M, solvent: DMF, temperature: 40 ° C., calibration: polystyrene). (3) Preparation of evaluation sheet material for porous sheet D The polyurethane resin solution was made to have a solid content concentration of 15% D
1m on polyester film after diluted with MF
m (wet thickness) coating, and immersed in a 30% DMF aqueous solution adjusted to 40 ° C. for 60 minutes to coagulate. Then, it was washed with warm water at 60 ° C. for 30 minutes and water at 25 ° C. for 10 minutes. After peeling the coagulated sheet from the polyester film, it was dried with hot air at 80 ° C. to obtain a sheet material. Evaluation method of sheet material Evaluation of the sheet material was performed as follows. Thickness: Thickness gauge (Manufacturer: Ozaki Seisakusho Model: LGS-
It was measured according to 10). Surface smoothness: The sheet surface was visually observed. Cross-section cell state: Electron microscope (maker:
It was observed with Hitachi, Ltd. model number: S-800). Texture: Judgment was performed by a sensory test based on the tactile sensation of the hand. (4) Evaluation of hydrolysis resistance Preparation of dry film Polyurethane resin solution (resin concentration 30%) was applied on a glass plate subjected to mold release treatment to 0.9 mm (wet thickness),
After drying for 3 hours in a circulating air dryer at 70 ° C., it was peeled from the glass plate to obtain a dry film having a thickness of about 0.2 mm. The dry film prepared in the hydrolysis resistance accelerated test was left for 6 weeks in a constant temperature and humidity chamber adjusted to 70 ° C. and 95% relative humidity. Using the dry film obtained from the measurement of tensile strength and JIS K 63
According to No. 01, the tensile strength was measured. Condition; dumbbell:
No. 3, tensile speed: 300 mm / min. Tensile Strength Retention Rate Tensile strength retention rate is calculated by the following formula. (Tensile strength after hydrolysis resistance test / Tensile strength before hydrolysis resistance test) × 100

Production Example 1 A four-necked flask equipped with a stirrer and a thermometer was charged with 1,4
-Butanediol / 1,6-hexanediol (mol%
Ratio: 85/15) number average molecular weight 2,000 synthesized
124.2 parts of copolymerized polycarbonate diol having 0 (calculated from hydroxyl value) and polyneopentyl adipate diol having a molecular weight of 2000 (calculated from hydroxyl value) 82.8
Part, ethylene glycol (hereinafter abbreviated as EG) 17.0
, MDI 94.0 parts and DMF 742 parts,
A solution of a polyurethane resin (A-1) having a resin concentration of 30%, a viscosity of 90,000 mPa · s / 20 ° C., a number average molecular weight of 61,000, and a coagulation number of 10.2 by reacting for 15 minutes at 60 ° C. in a dry nitrogen atmosphere. Got The weight ratio of polycarbonate diol (a1) to polyester diol (a2) is 6
It is 0:40. The content of nitrogen derived from the organic diisocyanate component in the solid content of (A-1) is 3.3.
% By weight.

Production Example 2 1,4-butanediol / 1,6-hexanediol (molar% ratio: 70/30) was placed in the same reaction vessel as in Production Example 1.
Copolymerized polycarbonate diol 146.0 having a number average molecular weight of 2,000 (calculated from a hydroxyl value) synthesized from
Parts, number average molecular weight 2000 (calculated from hydroxyl value) polyethylene adipate diol 62.4 parts, EG 13.1
, MDI 78.8 parts and DMF 700 parts,
A solution of a polyurethane resin (A-2) having a resin concentration of 30%, a viscosity of 82,000 mPa · s / 20 ° C., a number average molecular weight of 58,000, and a coagulation number of 11.0 after reacting for 15 hours at 60 ° C. in a dry nitrogen atmosphere. Got The weight ratio of (a1) and (a2) is 70:30. The content of nitrogen derived from the organic diisocyanate component in the solid content of (A-2) was 2.9% by weight.

Production Example 3 In the same reaction vessel as in Production Example 1, 1,4-butanediol / 1,6-hexanediol (mol% ratio: 90/10) was added.
Copolymerized polycarbonate diol 145.6 having a number average molecular weight of 2,000 (calculated from a hydroxyl value) synthesized from
Parts, polybutylene adipate diol having a molecular weight of 2000 (calculated from a hydroxyl value) 62.4 parts, 1,4-butanediol 21.5 parts, MDI 85.4 parts and DMF735.
Part, and allowed to react for 13 hours at 60 ° C. in a dry nitrogen atmosphere, resin concentration 30%, viscosity 75,000 mPa · s /
A solution of polyurethane resin (A-3) having a number average molecular weight of 56,000 and a coagulation number of 10.6 was obtained at 20 ° C. The weight ratio of (a1) and (a2) is 70:30. The content of nitrogen derived from the organic diisocyanate component in the solid content of (A-3) was 3.0% by weight.

Production Example 4 1,4-butanediol / 1,5-pentanediol (mol% ratio: 80/2) was placed in the same reaction vessel as in Production Example 1.
0) a copolymerized polycarbonate diol having a number average molecular weight of 2,000 (calculated from a hydroxyl value) 172.
7 parts, polyneopentyl adipate diol having a molecular weight of 2000 (calculated from a hydroxyl value), 57.6 parts, EG11.6
, MDI 75.2 parts and DMF 740 parts,
A solution of a polyurethane resin (A-4) having a resin concentration of 30%, a viscosity of 81,000 mPa · s / 20 ° C., a number average molecular weight of 63,000, and a coagulation number of 9.5 by reacting at 60 ° C. for 16 hours under a dry nitrogen atmosphere. Got The weight ratio of (a1) and (a2) is 75:25. (A-4) The content of nitrogen derived from the organic diisocyanate component in the solid content is
It was 2.7% by weight.

Comparative Production Example 1 Polyhexamethylene carbonate diol 2 having a number average molecular weight of 2,000 (calculated from a hydroxyl value) was synthesized from 1,6-hexanediol in the same reaction vessel as in Production Example 1.
36.0 parts, EG 10.1 parts, MDI 70.3 parts and DMF 738 parts were charged and allowed to react at 60 ° C. for 18 hours in a dry nitrogen atmosphere, resin concentration 30%, viscosity 85,000.
A solution of a polyurethane resin (A-5) having a mPa · s / 20 ° C., a number average molecular weight of 62,000 and a coagulation number of 5.6 was obtained.
The content of nitrogen derived from the organic diisocyanate component in the solid content of (A-5) was 2.5% by weight.

Comparative Production Example 2 1,4-butanediol / 1,6-hexanediol (mol% ratio: 30/7) was placed in the same reaction vessel as in Production Example 1.
0), a copolymerized polycarbonate diol having a number average molecular weight of 2,000 (calculated from a hydroxyl value) 241.
0 parts, EG 5.8 parts, MDI 53.6 parts and DMF7
00 parts were charged and reacted in a dry nitrogen atmosphere at 60 ° C. for 14 hours to give a resin concentration of 30% and a viscosity of 67,000 mPa · s.
s / 20 ° C, number average molecular weight 55,000, coagulation number 6.5
A polyurethane resin (A-6) solution was obtained. (A-
6) The content of nitrogen derived from the organic diisocyanate component in the solid content was 2.0% by weight.

Examples 1 to 4 and Comparative Examples 1 to 2 Using the polyurethane resins obtained in Production Examples 1 to 4 and Comparative Production Examples 1 and 2, Examples 1 to 4 and Comparative Examples 1 and 2 were used.
The porous sheet of was prepared by the method described above. The shape and properties and hydrolysis resistance were evaluated by the methods described above. The results are shown in Table 1.

[0046]

[Table 1]

As is apparent from Table 1, the porous sheets of Examples 1 to 4 of the present invention have better shape and properties than the porous sheets of Comparative Examples 1 and 2. In addition, Examples 1 to 4 have a high level of hydrolysis resistance. On the other hand, the shapes and properties of the porous sheets of Comparative Examples 1 and 2 are not good and cannot be put to practical use.

[0048]

EFFECTS OF THE INVENTION The porous sheet material obtained by the method of the present invention has characteristics that it is superior in wet film-forming property and has good texture and flexibility as compared with conventional porous sheet materials of polycarbonate-based polyurethane resin. . Further, hydrolysis resistance, heat resistance, light resistance, and physical properties (tensile strength, elongation, bending resistance, etc.) are as excellent as those of conventional polycarbonate-based polyurethane resin porous sheet materials. Therefore, since the porous sheet material of the present invention exhibits the above-mentioned effects, it is useful as a leather substitute in a wide range of applications such as shoes, bags, clothing, furniture, and vehicle seats.

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Claims (6)

[Claims] 1. A porous sheet obtained by applying a solution of a polyurethane resin (D) comprising a polymer diol (A), an organic diisocyanate (B) and optionally a chain extender (C) to a substrate by a wet film forming method. In the material, (A) is a polymer diol composed of a mixed diol of a polycarbonate diol (a1) and a polyester diol (a2), and (a1) is 1,4-butanediol or another C4-6. Consisting of one or more alkanediols and containing 50-90 mol% of 1,4-butanediol based on the total number of moles of the diols,
And a copolymerized polycarbonate diol having a number average molecular weight of 500 to 5,000, and a solidification number of (D) of 7 to
14. A porous sheet material, which is 14. 2. The weight ratio of (a1) to (a2) is 40: 6.
The material according to claim 1, which is 0 to 90:10. 3. The number average molecular weight of (D) is from 20,000 to
The material according to claim 1 or 2, which is 500,000. 4. The content of nitrogen derived from (B) in (D) is 2 to 4.5% by weight based on the weight of (D).
The material according to any one of claims 1 to 3, which is 5. (a1) is 1,4-butanediol,
And 1,5-pentanediol and / or 1,6
-Hexanediol is a copolymerized polycarbonate diol, wherein (a2) is ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,
At least one glycol selected from the group of 4-butanediol and neopentyl glycol, and 6 carbon atoms
The material according to any one of claims 1 to 4, which is a polyester diol synthesized from at least one kind of saturated aliphatic dicarboxylic acid of 10 to 10. 6. A porous sheet material is formed by a wet film-forming method by applying a solution of a polyurethane resin (D) comprising a polymer diol (A), an organic diisocyanate (B) and optionally a chain extender (C) to a substrate. In the method of manufacturing,
(A) is a polymer diol composed of a mixed diol of a polycarbonate diol (a1) and a polyester diol (a2), and (a1) is a 1,4-butanediol and another alkane diol having 4 to 6 carbon atoms. 50 to 90 mol% of 1,4-butanediol based on the total number of moles of the diol.
A method for producing a porous sheet material, which comprises a copolymerized polycarbonate diol having a number average molecular weight of 500 to 5,000 and a coagulation number of (D) of 7-14.