JPH02189345A - Production of porous sheet material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel method for producing porous sheet materials. More specifically, the present invention provides a polyurethane-based porous one-sheet material with excellent moisture permeability and durability suitable for use as materials such as synthetic leather and porous membranes, various moisture permeable materials, surface coating materials, etc. The present invention relates to an efficient and economically advantageous manufacturing method.

[Prior Art] Conventionally, polyurethane-based porous materials have been widely used as materials for synthetic leather, moisture-permeable waterproof cloth, and the like. As a method for manufacturing this porous polyurethane material, for example, a polyurethane layer is formed by dissolving a polyurethane polymer in a water-soluble solvent such as dimethylformamide, coating or impregnating a base material with this solution, and removing the solvent in water. A wet method for making the material porous, and a dry method for making the material porous by coating or impregnating a base material with a water-in-oil emulsion of polyurethane and then heating and drying to remove the organic solvent and water are known.

The former wet method requires a large amount of equipment in the desolvation process, takes a long time to perform sufficient desolvation, and has problems such as the need to treat a large amount of waste liquid.
The dry method is advantageous in terms of productivity and economy.

Conventionally, as a method for manufacturing a polyurethane porous material by this dry method, for example, the method described in Japanese Patent Publication No. 48579/1982 is known.

However, in this method, since a relatively large amount of hydrophilic polyurethane is used in the polyurethane component, the durability of the polyurethane layer is insufficient and the drying process is complicated.
In addition, there were drawbacks such as a long processing time.

[Problems to be Solved by the Invention] The present invention overcomes the drawbacks of the conventional dry method for producing polyurethane porous materials, and provides a polyurethane porous sheet with excellent moisture permeability and durability. The purpose of this invention is to provide a method for manufacturing materials efficiently and economically.

[Means for Solving the Problems] As a result of extensive research in order to achieve the above object, the present inventors found that an oil containing hydrophobic polyurethane as a main component and a small amount of hydrophilically modified polyurethane as an emulsifier component. It was discovered that the purpose could be achieved by using a wooden-shaped polyurethane emulsion, and the present invention was completed based on this knowledge.

That is, the present invention applies or impregnates a water-in-oil polyurethane emulsion containing (A) hydrophobic polyurethane, (B) hydrophilic polyurethane, and (C) organic solvent onto a sheet-like base material, and then dries it. In order to produce a porous sheet material, (A) the hydrophobic polyurethane is reacted with a hydrophobic polyol, an organic diisocyanate, and a chain extender in the (C) organic solvent that has limited solubility in water. CB) as the hydrophilic polyurethane, a hydrophobic polyol, an organic diisocyanate, a monocarboxylic acid having an unsaturated double bond, and one active hydrogen of a trifunctional active hydrogen compound. Provided is a method for producing a porous sheet material characterized by using a modified polyurethane obtained by copolymerizing a hydrophilic vinyl 7-mer with an unsaturated double bond-containing polyurethane obtained by reacting a condensate with It is something.

The present invention will be explained in detail below.

The wood-in-oil polyurethane emulsion used in the method of the present invention contains a hydrophobic polyurethane (component (A)) as a main component, and this hydrophobic polyurethane is prepared by adding a hydrophobic polyol, an organic diisocyanate, and a chain extender to an organic solvent. It can be obtained by reacting in

Examples of the hydrophobic polyol include polyether polyols such as polytetramethylene ether glycol and polypropylene glycol having an average molecular weight of preferably 400 to 3000, and polyethylene adipate with a bifunctional terminal hydroxyl group obtained by a condensation reaction between a diol and a dicarboxylic acid. , polybutylene adipate, polypropylene adipate, polyhexamethylene adipate, polyester polyols such as polycaprolactone and polymethylvalerolactone, and polycarbonate polyols. One type of these hydrophobic polyols may be used, or two or more types may be used in combination.

Examples of the organic diisocyanate include 4.4-diphenylmethane diisocyanate, 2.4- or 2.6-diisocyanate.
- Aromatic diisocyanates such as 1-lylene diisocyanate, 1.5-naphthalene diisocyanate, p- or m-phenylene diisocyanate, alicyclic diisocyanates such as inphorone diisocyanate, 4.4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, etc. Examples include aliphatic diisocyanates. One type of these organic diisocyanates may be used, or two or more types may be used in combination.

Examples of the chain extender include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1, 6
- Short chain diols such as hexanediol, ethylenediamine, l,2-propanediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, inphoronediamine, 4.4°-dicyclohexylmethanediamine, m-xylylenediamine, etc. Other examples include diamines, hydrazine, and water.

These chain extenders may be used alone or
You may use two or more types in combination.

The organic solvent used in the production of the hydrophobic polyurethane (A) constitutes the (C) component in the water-in-oil polyurethane emulsion and has a limited solubility in water. Preferably, it dissolves in a proportion of 50% by weight and has a boiling point of 120°C or less. Examples of such solvents include ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and methyl-n-propyl ketone; ester solvents such as ethyl acetate, butyl acetate, ethyl formate, and propyl formate; and acetone and tetrahydro-7. Ran, dioxane, methanol, ethanol, ingropanol, n- or 5ec-butanol, cyclohexane, toluene, xylene, ethylene dichloride,
Trichlorethylene, cyclohexanone, dimethylformamide, dimethyl sulfoxide, ethyl cellosolve,
Examples include butyl cellosolve and cellosolve acetate. These solvents may be used alone or in combination of two or more, but among them, those that have too high a solubility in water or those that do not dissolve in water have a high solubility in water. Use by mixing with other solvents within a limited range,
Further, it is desirable to use as little amount of a solvent with a high boiling point as possible.

In the method of the present invention, the hydrophobic polyurethane used as component (A) is obtained by reacting the above-mentioned hydrophobic polyol, organic diiso/anate, and chain extender in these organic solvents. Catalysts commonly used in urethanization reactions, such as organometallic catalysts such as dibutyltin dilaurate, siphytyltin dioctoate, and dibutyltin diacetate, and secondary amine catalysts such as triethylenediamine, can be used. Further, the reaction temperature is preferably below the boiling point of the solvent used, and is usually selected within the range of 30 to 120°C. Furthermore, the solids content of the hydrophobic polyurethane thus obtained is preferably in the range of 10 to 50% by weight.

In the method of the present invention, the hydrophilic polyurethane used as component (B) of the water-in-oil polyurethane emulsion contains the above-mentioned hydrophobic polyol, an organic diisocyanate, and a specific chain extender containing an unsaturated double bond. A)
React in the same way as the component hydrophobic polyurethane,
It is obtained by forming an unsaturated double bond-containing polyurethane and then copolymerizing a hydrophilic vinyl 7th polymer in a proportion of usually 5 to 50% by weight based on the solid content of the polyurethane.

The specific chain extender can be obtained by condensing a monocarboxylic acid having an unsaturated double bond or a reactive derivative thereof such as an acid chloride with one active hydrogen of a trifunctional active hydrogen compound by a conventional method. Since the condensate has two active hydrogen atoms in its molecule, it can be used as a chain extender for polyurethane. Examples of the monocarboxylic acid having an unsaturated double bond used to obtain the chain extender include acrylic acid, methacrylic acid, vinyl acetic acid, allyl acetic acid, and the like. On the other hand, examples of trifunctional active hydrogen compounds include glycerin, trimethylolpropane, triols obtained by adding alkylene oxides such as propylene oxide and ethylene oxide to these, and jetanolamine and triethanolamine.

These particular chain extenders have an average molecular weight of about 140-1
It is desirable that the amount is in the range of 200, and the amount used is usually 0.6 mol or less per 1 mol of organic diizo/aun-1 used in the production of the unsaturated double bond gold-containing polyurethane. You can choose. In addition, when producing the unsaturated double bond-containing polyurethane, other ordinary chain extenders such as those mentioned above may be used in combination, or the isonia atom group at the end of the polyurethane may be replaced with a monofunctional group such as a monoalcohol. It may also be blocked with a sexually active hydrogen compound.

The unsaturated double bond-containing polyurethane obtained in this way has high addition polymerizability, and by copolymerizing it with a hydrophilic vinyl monomer, the hydrophilic polyurethane of component (B) can be obtained. .

The hydrophilic vinyl monomer is nonionic or ionic 1
It can be any raw one. Examples of nonionic monomers include vinyl monomers having hydroxyl groups, polyoxyethylene groups, glycidyl groups, tetrahydrofurfuryl groups, amide groups, pyrrolidone groups, etc. Specific examples include acrylic acid, methacrylic acid, etc. 2-Hydroquinoethyl ester, 2-hydroxypropyl ester, glycerin ester, polyoxyethylene glycol ester, polyoxyethylene glycol ester, methoxypolyoxyethylene glycol ester, polyoxyethylene oxy/propylene block polyol ester, polyoxyethylene oxytetra Examples include methylene bronch polyol ester, glycidyl ester, tetrahydrofurfuryl alcohol ester, acid amide, N-methylolamide, N-vinylformamide, and N-vinylpyrrolidone.

Examples of ionic monomers include vinyl monomers having carpoyl groups, sulfonic acid groups, sodium sulfonate bases, tertiary amine 7 groups, quaternary ammonium bases, etc. Specific examples include: acrylic acid,
Methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, sulfonated styrene, sodium styrene sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl arylate, diethylaminoethyl Examples include methacrylate, vinylpyridine, and hydroquinepropyltrimethylammonium chloride methacrylate. In addition, when a vinyl monomer having a carboxyl group or a sulfonic acid group is used, the copolymer may be converted into a quaternary ammonium salt using benzyl chloride or the like.

These hydrophilic vinyl monomers may be used alone or in combination of two or more, or in order to adjust the degree of hydrophilicity of the given water-based polyurethane,
Other hydrophobic vinyl monomers such as alkyl esters of acrylic acid or methacrylic acid such as methyl, ethyl, propyl, butyl, styrene, methylstyrene, ethylstyrene, dimethylstyrene, methoxystyrene, and talolostyrene can be used in combination. .

In this copolymerization, it is possible to use polymerization initiating agents conventionally used in radical polymerization, such as organic peroxides such as benzoyl peroquinide and azo compounds such as azobisisobutyronitrile. In order to adjust the degree of polymerization, a chain transfer agent such as /lcapta 7 or carbon tetrachloride, or a conventional polymerization terminator may be used.

The hydrophilically modified polyurethane of component (B) thus obtained is an organic solvent solution or a dispersion containing water, and the solid content thereof is preferably in the range of 5 to 50% by weight. In addition, this hydrophilic polyurethane of component (B) has an action as an emulsifier for the water-in-oil polyurethane emulsion used in the present invention, and is the main component (
A) For the hydrophobic polyurethane component, 1 in terms of solid content
It is desirable to use it in a proportion of ~20% by weight. On this occasion,
If desired, for the purpose of adjusting the properties of the water-in-oil polyurethane emulsion, conventional emulsifiers such as polyoxyethylene oxypropylene block polyol, polyhydric alcohol fatty acid esters, and other emulsion stabilizers can also be used in combination. .

The water-in-oil polyurethane emulsion used in the method of the present invention is prepared by mixing a mixture of the hydrophobic polyurethane (A) component and the hydrophilic polyurethane (CB) component using an emulsifying dispersion machine such as a homomixer. It is obtained by adding a saturated amount or less of water, preferably 50 to 400 parts by weight of water to 100 parts by weight of solids of the polyurethane mixture, little by little under high speed stirring. At this time, additives such as antioxidants, ultraviolet stabilizers, colorants, lubricating agents, crosslinking agents, and fillers may be added as required.

The sheet-like base material used in the method of the present invention includes:
Examples include woven fabrics, nonwoven fabrics, knitted fabrics, films, paper, release paper, plastic plates, glass plates, metal plates, and the like. In the method of the present invention, the above-mentioned water-in-oil polyurethane emulsion is coated or impregnated on these base materials according to a commonly used method, and then dried to obtain the desired porous sheet material. . At this time, the solid content concentration, viscosity, coating amount, or impregnation amount of the polyurethane emulsion can be appropriately selected depending on the use of the resulting porous sheet material.

Moreover, by using the water-in-oil polyurethane emulsion according to the present invention, a homogeneous porous sheet material can be obtained by a very short drying process. For example, the polyurethane emulsion is coated or impregnated onto a substrate, heated for about 1 minute at a temperature preferably in the range of 60 to 100°C, and then heated to a temperature preferably in the range of 100 to 150°C. A desired porous sheet material can be obtained by a drying process such as heating for about 1-45').

That is, according to the method of the present invention, Japanese Patent Publication No. 5848579
A polyurethane-based porous sheet material can be obtained economically and with good productivity without using the complicated and time-consuming drying and coagulation steps described in the above publication.

The polyurethane porous sheet material obtained by the method of the present invention has a good feel and is excellent in moisture permeability and durability, so it can be used as synthetic leather and moisture permeable materials, such as clothing, shoes, bags, waterproof cloth, It can be used for tents, furniture, medical materials, wall materials, floor materials, surface coating materials for various molded parts, and even air filters and filter media. Further, the porous sheet material may be used together with a base material, or may be used after being peeled from the base material.

[Function] In the water-in-oil polyurethane emulsion used in the method for producing porous sheet materials of the present invention, a water amount of hydrophilic polyurethane acts as an emulsifier in an oil phase consisting of a hydrophobic polyurethane as a main component and an organic solvent. to disperse the water,
This stabilizer is applied to or impregnated onto a base material, and then dried at a temperature of 100°C or less, so that most of the organic solvent first evaporates, and then the 100°C
By drying at a temperature above '0, water and the remaining solvent dissolved in water evaporate, making the polyurethane layer porous
It is thought that communication and coagulation occur in a short time.

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited in any way by these examples.

Example 1 200 parts by weight of polytetramethylene ether glycol (hereinafter abbreviated as PTMG) having an average molecular weight of 1000, 1 part by weight of diphinylmethane diisocyanate (hereinafter abbreviated as MDI)
37.5 parts by weight, 338 parts by weight of methyl ethyl ketone (hereinafter abbreviated as MEK) and 0 parts of dibutyltin dioctoate
．． After charging 4 parts by weight of 0.04 parts by weight into a reactor and reacting at 60°C for about 2 hours, 500 parts by weight of MEK and 21.7 parts by weight of ethylene glycol were added, and the reaction was further carried out at 70°C for about 6 hours, and then the temperature was lowered to room temperature while stirring. Cool to a solid content of 3
A cloudy white polyurethane dispersion (A1) containing 0% by weight was obtained.

Example 2' - 200 parts by weight of polybutylene adipate having an average molecular weight of 1000, 1125 parts by weight of MD, 325 parts by weight of MEK and 0.04 parts by weight of dibutyltin dioctoate were charged into a reactor, and after reacting at 60°C for about 2 hours, MEK496
parts by weight, add 27 parts by weight of 1,4-butanediol, and add 7 parts by weight.
The reaction was continued at 0° C. for about 6 hours, and then cooled to room temperature while stirring to obtain a cloudy white polyurethane dispersion (A2) with a solid content of 30% by weight.

Example 3 - PTMGI OONN having an average molecular weight of 1000 82 parts by weight of polycaprolactone polyester polyol having an average molecular weight of 820, 1125 parts by weight of MD, 307 parts by weight of MEK and 0.03 parts by weight of dibutyltin dilaurate were charged into a reactor, and 60'C! After reacting for about 2 hours, M
EK472]i parts by weight and 27 parts by weight of 1,4-butanediol were added, and the reaction was further carried out at 60°C for about 7 hours, and then cooled to room temperature while continuing to stir. A dispersion liquid (A3) was obtained.

Example 4 PTMGl with average molecular filooo 00 parts by weight, MD
50 parts by weight of I, 100 parts by weight of MEK, and 0.01 parts by weight of dibutyltin diacetate were charged into a reactor, and the temperature was set at 50°.
After reacting with C for about 2 hours, 8 parts by weight of glycerol monomethacrylate and PTMG 10 with an average molecular weight of 1000 were added.
Add 0 parts by weight, 287 parts by weight of MEK, and further 50°
After reacting at C for about 2 hours, the solid content was 40% by weight and the viscosity was 500.
A polyurethane solution of c ps / 25 °C was obtained.

Next, to 100 parts by weight of this polyurethane solution, 5 parts by weight of 2-hydroxyethyl acrylate, 6.5 parts by weight of n-butyl acrylate, 60 parts by weight of MEK, 1 part by weight of 35 parts of isopropyl alcohol, and 0.0 parts by weight of benzoyl peroxide.
Add 15 parts by weight and react at 70°C for about 6 hours to obtain a solid content of 25% by weight and a viscosity of 8000 cps/25
A hydrophilically modified polyurethane solution (B,) at °C was obtained.

Example 5 After obtaining a polyurethane solution before being modified to make it hydrophilic in the same manner as in Example 4, 25 parts of methoxypolyoxyethylene glycol monomethacrylate having an average molecular weight of 500 was added to 100 parts by weight of the polyurethane solution in Notherme, Tokyo. Kukrylate 5
Jujuto, MEK 140 parts by weight, 5ec-butanol 80
parts by weight, add 0.3 parts by weight of arabisisobutyronitrile, and 70'C! The reaction was carried out for about 6 hours to obtain a hydrophilic modified polyurethane solution (B2) with a solid content of 20% by weight and a viscosity of 2000 c'ps/25°C.

Example 6 Polypropylene azibe 1-24 with an average molecular weight of 2000
0 parts by weight, 35 parts by weight of MDI, 275 parts by weight of MEK, parts by weight of dibutyltin dioctoate o, oos were charged into a reactor, and after reacting at 60°C for about 2 hours, 6.4 parts by weight of glycerol monomethacrylate and 2 parts by weight of MEK 3g In addition, the solid content was reduced to 3 by further reacting at 40°C for about 4 hours.
A polyurethane solution of 0% by weight and a viscosity of 6000 cps/25°C was obtained.

Next, 5 parts by weight of N-vinylformamide and 51 parts by weight of tetrahydrofurfuryl acrylate were added to 100 parts by weight of this polyurethane solution. 1 part of E, 30 parts by weight of MEK, 20 parts by weight of tetrahydrofuran, 0 parts of azobisisobutyronitrile
．． Add 3 parts by weight and react at 70°C for about 7 hours to obtain a solid content of 25% by weight and a viscosity of 15000 cps/25
A hydrophilically modified polyurethane solution (B,) at °C was obtained.

Example 7 After obtaining a polyurethane solution before being modified to be hydrophilic in the same manner as in Example 6, N-
12 parts by weight of vinylpyrrolidone, 6 parts of ethyl methacrylate
Parts by weight, 85 parts by weight of MEK, 3 parts by weight of Improvil alcohol
Add 0.3 parts by weight of azobisisobutyronitrile and react at 75°C for about 6 hours to obtain a hydrophilic modified polyurethane solution (B4) with a solid content of 20% by weight and a viscosity of 4000 cps/25°C. I got it.

Example 8 Polypropylene glycol 200 with an average molecular weight of 2000
1i quantity, MDI501! After charging 167 parts by weight of MEK and 0.02 parts by weight of dibutyltin dioctoate into a reactor and reacting at 70°C for about 3 hours, 8 parts by weight of glycerol monomethacrylate and 231 parts by weight of MEK were added and the mixture was heated at 50°C. 7.4 parts by weight of n-butanol was further added and the reaction was carried out at 50°C for about 2 hours to obtain a solid content of 40% by weight and a viscosity of 2000 cps/
A polyurethane solution at 25°C was obtained.

Next, 4 parts by weight of 2-acrylamido-2-methylpropanesulfonic acid was added to 100 parts by weight of this polyurethane solution.
Parts by weight of dimethylaminoethyl methacrylate, MEK5
0 parts by weight, 40 parts by weight of dimethylformamide, and 0.3 parts by weight of azobisinbutyronitrile were added and reacted at 60°C for about 7 hours to obtain a solid content of 25% by weight and a viscosity of 5000c.
ps/25°C hydrophilically modified polyurethane solution (
B.) was obtained.

Example 9 After obtaining a polyurethane solution before being modified to be hydrophilic in the same manner as in Example 4, 5 parts by weight of acrylic acid and 701110 parts by weight of hydroxy-7-propyltrimethylammonium methacrylate were added to 100 parts by weight of the polyurethane solution. Department, MEK1
00 parts by weight and 0.3 parts by weight of azobisisobutyronitrile were added, reacted at 80°C for about 5 hours, and further added 60 parts by weight of water to give a solid content of 20% by weight and a viscosity of 200 cp.
A modified polyurethane dispersion (B6) at s/25°C was obtained.

Examples 10-16 The hydrophobic polyurethanes and hydrophilic polyurethanes obtained in Examples 1 to 9 were mixed with an organic solvent in the proportions shown in Table 1,
A water-in-oil polyurethane emulsion was produced by adding water while vigorously stirring with a homomixer. The solids content and viscosity of this polyurethane emulsion are shown in Table 1.

(The following is a blank space) Examples 17 to 23 Using the liquid mixtures obtained in Examples 1O to 16, the mixtures were applied to each base material as shown in Table 2, and dried to form the polyurethane porous object of the present invention. A quality sheet material was obtained. The performance of this product is shown in Table 2.

(The following is a blank space) L Effects of the Invention J According to the present invention, a porous polyurethane sheet material having excellent moisture permeability and durability can be efficiently and economically advantageously produced. The polyurethane porous sheet material obtained in the present invention can be suitably used as, for example, materials for synthetic leather and porous membranes, various moisture permeable materials, surface coating materials, and the like.

Claims (1)

[Claims] 1. On a sheet-like base material, (A) hydrophobic polyurethane, (B
) A water-in-oil polyurethane emulsion containing a hydrophilic polyurethane and (C) an organic solvent is coated or impregnated and then dried to produce a porous sheet material. , using a polyurethane dispersion or solution obtained by reacting a hydrophobic polyol, an organic diisocyanate, and a chain extender in the (C) organic solvent that has limited solubility with water, and as the (B) hydrophilic polyurethane. , hydrophobic polyol,
A hydrophilic vinyl monomer is added to an unsaturated double bond-containing polyurethane obtained by reacting an organic diisocyanate and a condensate of a monocarboxylic acid having an unsaturated double bond with one active hydrogen of a trifunctional active hydrogen compound. A method for producing a porous sheet material, characterized by using a modified polyurethane obtained by copolymerization.