JPS61133242A - Production for porous sheet material - Google Patents

Abstract

PURPOSE:To obtain a material having a film which is easily formed and has improved water resistance, etc., by dispersing polyurethane, a dispersant of modified polyurethane into a mixed solvent of a good solvent and a bad solvent for polyurethane to give dispersion, impregnating or applying it to a substrate, and drying it. CONSTITUTION:Polyurethane, and a dispersant of a modified polyurethane which consists of a nonionic additional polymerizable monomer and has a graft polymerization chain are dispersed into a mixed organic solvent of a good solvent and a bad solvent for polyurethane to give polyurethane dispersion wherein the graft polymer chain of the dispersant is solvent with the solvent, which is impregnated and/or applied to a substrate, and dried. A polyurethane, obtained by replacing partially - totally polyol and/or chain extender with a polycondensation product of itaconic acid, etc. and hydrazine, etc., when a polyethylene adiptate having terminal OH group and 300-4,000 molecular weight is reacted with both MDI, etc., and the chain extender, is preferably used as the modified polyurethane.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for producing porous polyurethane sheet materials, and is a method for producing porous sheet materials with excellent mechanical properties, water vapor permeability, etc. The purpose is to provide sex.

(Prior Art) Many porous sheet materials made of polyurethane as natural leather substitutes and methods for producing them have been known, and can be roughly divided into wet methods and dry methods.

(Problem to be solved by the invention) Both methods have their advantages and disadvantages, and the dry method is superior in terms of productivity. As such a dry method, for example, the
There are methods described in Japanese Patent Application Laid-open No. 18249 and Japanese Patent Application Laid-open No. 51-41063, but these conventional methods use a relatively large amount of hydrophilic polyurethane to form a polyurethane layer. It cannot be said that its physical and chemical properties are sufficient, and its manufacturing method requires a complicated and time-consuming drying process, which is a decisive drawback.

As a result of intensive research in order to solve the above-mentioned drawbacks of the prior art, the present inventors have made polyurethane dispersion in an organic solvent the main component of the coating forming material, and on the other hand, hydroxyl groups, acid amide groups, glycidyl groups or polyoxyethylene It has been found that the above-mentioned drawbacks of the prior art can be solved by using a small amount of a modified polyurethane obtained by graft polymerizing a nonionic finisher such as an addition-polymerizable 7mer containing chains as a dispersant for the polyurethane. The present invention was completed.

(Means for Solving the Problems) That is, the present invention consists of an organic solvent, polyurethane dispersed in the organic solvent, and a dispersant, and a solvent that is a good solvent and a poor solvent for the polyurethane in which the organic solvent is dispersed. A modified polyurethane which is a mixed solvent with a solvent as a solvent and has a graft polymer chain in which the dispersant is a nonionic addition polymerizable monomer, and the graft polymer chain is solvated by the organic solvent. This is a method for producing a porous sheet material, which comprises impregnating and/or coating a base material with a polyurethane dispersion, and drying the polyurethane dispersion.

To explain the present invention in more detail, the main feature of the method of the present invention is that a modified polyurethane obtained by introducing a graft polymer chain consisting of a nonionic addition-polymerizable monomer into polyurethane is used as a dispersant for the polyurethane to be dispersed. This is the point that was used as

The modified polyurethane used as a dispersant in the method of the present invention can be obtained by graft polymerizing a nonionic addition-polymerizable monomer to a general polyurethane using a peroxide or the like as a catalyst, or preferably, by first adding an addition-polymerizable monomer to the main chain. It is obtained by a method of forming a polyurethane having a bond, and then graft-polymerizing a nonionic addition polymerizable monomer to the polyurethane.

Such a modified polyurethane is preferably used as all or a part of the polyol and/or chain extender when synthesizing polyurethane from a polyol, an organic diisocyanate, and a chain extender that are known for the production of polyurethane. It is obtained by graft polymerizing an addition polymerizable monomer to the obtained polyurethane using a chain extender having a double bond.

Preferred examples of such polyols include polyols having a terminal group of hydroxyl group t and a molecular weight of 300 to 4.0
00 polyethylene adipate, polyethylene propylene adipate, polyethylene butylene adipate, polydiethylene adipate, polybutylene adipate, polyethylene succinate, polybutylene succinate, polyethylene sebacate, polybutylene sebacate, polytetramethylene ether glycol, poly-6-caprolactone Examples include diol, polyhexamethylene adipate, carbonate polyol, and polypropylene glycol.

As the organic diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), water-added MDI, inphorone diisocyanate, l.

Examples include 3-xylylene diisocyanate, 1.4-xylylene diisocyanate, 2.4-)lylene diisocyanate, 2.6-lylene diisocyanate, 1.5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, and the like.

Examples of chain extenders include ethylene glycol, propylene glycol, diethylene glycol, lI4-butanediol 1,1,6-hexanediol, ethylenediamine, 1,2-propylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine,
Examples include decamethylene diamine, inphorone diamine, m-xylylene diamine, hydrazine, and water.

Furthermore, the chain extender having an addition-polymerizable double bond preferably used in the present invention has an average molecular weight of about 140 to An unsaturated compound having active hydrogen at both ends of t and ooo (hereinafter referred to as a specific chain extender) is preferable, and this specific chain extender includes itaconic acid, fumaric acid, maleic anhydride, citraconic acid, etc. unsaturated dibasic acids or their functional derivatives, diamines such as hydrazine, ethylenediamine, piperazine, propylene diamine, xylylene diamine, inphoron diamine, ethylene glycol, i-butanediol,
1.3-butanediol, 2.3-butanediol, propylene glycol, diethylene glycol, 1.5-
Ninomiya saturated compounds having active hydrogen such as glycols such as bentanediol, neopentyl glycol and dipropylene glycol, amine alcohols such as monoethanolamine and dimethylethanolamine, and about 1 per mole of unsaturated dibasic acid. They are obtained by polycondensation at a ratio of .2 to 2.0 moles, and particularly preferred are those having an average molecular weight of about 140 to 1.000.

This polycondensation reaction itself may be carried out by a conventionally known method, for example, in an inert gas atmosphere at a reaction temperature of 150 to 240°C in the presence of a catalyst such as a sulfonate compound or a titanate compound for about 3 to 15 hours. Conditions are favorable. Such a specific chain extender is used in the method of the present invention in a ratio of o,oot to 0.5 mole per mole of polyol.

By graft-polymerizing a nonionic addition-polymerizable monomer to the polyurethane having an addition-polymerizable double bond in the main chain obtained as described above, a preferable modified polyurethane which mainly characterizes the method of the present invention can be obtained.

Any nonionic addition-polymerizable monomer used as a modifier in the present invention may be any known one.

For example, amides of unsaturated carboxylic acids such as acrylic acid, α-chloroacrylic acid, methacrylic acid, N-methylolamide, 2-hydroxyethyl ester, etc. Examples include nonionic parent wood finishers such as -hydroxypropyl ester, glycidyl ester, or polyoxyethylene glycol ester. In addition to these 7-ionic monomers, other monomers such as acrylic acid, methacrylic acid, α-chloroacrylic acid, α-chloromethacrylic acid, maleic acid, itaconic acid, and vinyl sulfone may be used as long as they do not interfere with the purpose of the present invention. Nitrogen-containing vinyl monomers such as acid, sulfonated styrene-12-acrylamido-2-methylpropanesulfonic acid, dimethylaminoethyl acrylate, dimethylamine ethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, vinylpyridine, vinylnaphthalene, or 4 of these Ionic finishing nomers such as acrylic acid, α-chloroacrylic acid, methacrylic acid, methyl, ethyl, propyl, butyl, stearyl, lauryl, octyl, 2-ethylhexyl, hexyl ester; styrene, methylstyrene, dimethylstyrene , ethylstyrene, methoxystyrene, divinylbenzene,
Hydrophobic monomers such as α-methylstyrene, β-methylstyrene, chlorstyrene, 2,5-dichlorostyrene, α-chlorostyrene or derivatives thereof can be used in combination with the above-mentioned nonionic monomers. Such monomers are used in the polyurethane resin 100 before modification.
It is used in a ratio of 0.5 to 0.00 parts by weight per part by weight.

The type of monomer used varies depending on the organic solvent used as the dispersion medium and the use of the resulting dispersion.

The method of modification using such monomers itself may be a known method. For example, the above-mentioned polyurethane resin and monomer may be polymerized with benzoyl peroxide, azobisisobutyronitrile, etc. at a temperature of 70 to 90°C in an inert gas atmosphere. This can be carried out by graft polymerization for 6 to 10 hours in the presence of an initiator. .

The above is a preferable method for producing the modified polyurethane used in the present invention. However, in addition to the above preferable method, for example, the above-mentioned method can be used without introducing an addition-polymerizable double bond into polyurethane, using a peroxide or the like as a catalyst. A method of graft polymerizing various monomers such as the following may also be used.

The modified polyurethane described above may be obtained as an organic solvent solution using various organic solvents as described below, may be obtained as a dispersion in an organic solvent, or may be obtained without using an organic solvent. good.

In the present invention, the polyurethane that is stably dispersed by the dispersant, which is the modified polyurethane described above, may be any conventionally known polyurethane, preferably obtained by a conventionally known method from the aforementioned polyol, organic diisocyanate, and chain extender. I can do it. Such polyurethane to be dispersed may also be a solution of an organic solvent, a dispersion in an organic solvent, or may be obtained without using an organic solvent.

The polyurethane dispersion used in the method of the present invention can be obtained by dispersing the above-mentioned polyurethane in the below-mentioned organic solvent using the above-mentioned modified polyurethane as a dispersant.

Any method may be used for dispersing, and for example, preferred methods include (1) adding a dispersant dissolved in an organic solvent to precipitate the polyurethane to an organic solvent solution of the polyurethane to be dispersed; A method of dissolving polyurethane and a dispersant in the same organic solvent and adding an organic solvent that precipitates at least the polyurethane to be dispersed;
(3) Prepare a dispersion of polyurethane to be dispersed,
A method of adding a dispersant or its solution into this, (4)
Examples include a method in which a dispersion of a dispersant in an organic solvent in which at least the graft polymer chains of the dispersant are solvated is added to a solution or dispersion of the polyurethane to be dispersed. In either method or in other methods, it is necessary that the dispersant in the resulting dispersion be dissolved or at least that the graft polymer chains of the dispersant be solvated by the organic solvent. By doing so, the object of the present invention is achieved. Such a condition is the only one
It is also possible to use different organic solvents, but two types with different properties can be used.
This can be easily achieved by using a combination of more than one type of organic solvent.

For example, in the case of a dispersant, the addition-polymerizable polymer that is graft-polymerized has a hydroxyl group.

Because it has polar groups such as ether groups and ester groups, water,
It is preferable to use a polar organic solvent such as alcohol, ketone, ether, or amide as part of the solvent.

Examples of the organic solvent used as a dispersion medium in the present invention include methyl, ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, butyl acetate, and acetone. , cyclohexane, tetrahydrofuran, dioxane, methanol, ethanol, isopropyl alcohol, butanol, methyl cellosolve, butyl cellosolve, cellosolve acetate, dimethyl formamide, dimethyl sulfoxide, pentane, hexane, cyclohexane, heptane, octane, mineral spirits, petroleum ether, gasoline, benzene, Examples include toluene, xylene, chloroform, carbon tetrachloride, chlorobenzene, perchlorethylene, trichlorethylene, etc. Among these, there are organic solvents that are good solvents and poor solvents for the polyurethane to be dispersed. It is preferable to use the dispersant in combination with at least an organic solvent that solvates the graft polymer chain, and further select and use a combination based on the assumption that a good solvent has a higher evaporation rate than a poor solvent. It is best to do so. In addition, regarding the amount used, the ratio of good solvent to poor solvent is 100:10 to 200.
(weight ratio) is preferable.

The polyurethane dispersion used in the present invention as described above has a total concentration of the polyurethane to be dispersed and the dispersant of about 5 to 70% by weight, and the ratio of the polyurethane to be dispersed to the dispersant is 100:1. A weight ratio of -100 is convenient for its use.

In the polyurethane dispersion used in the present invention as described above, the polyurethane to be dispersed is in contact with and surrounded by the main chain polyurethane of the dispersant, while the graft polymer chains of the dispersant are at least solvated by the organic solvent as the medium. It has excellent dispersion stability and does not gel or form sediment even after a long period of time.
When forming a film, the good solvent in the medium evaporates first, so
Gelation during film formation is extremely easy. Furthermore, since the polyurethane dispersion used in the present invention is a dispersion rather than a solution, it does not have high viscosity and has excellent suitability for various uses. Unlike conventional polyurethane dispersions, it does not contain water-soluble surfactants that reduce the water resistance of products, so it is possible to form a film with excellent water resistance. Furthermore, since the polyurethane dispersion used in the present invention is not an aqueous dispersion, a large amount of energy is not consumed in forming a film.

Various additives such as colorants, crosslinking agents, stabilizers, fillers, and other known additives may be optionally added to such a dispersion as necessary.

Examples of the base material used in the present invention include various woven fabrics, knitted fabrics, nonwoven fabrics, release paper, plastic films, metal plates,
The dispersion may be applied to any base material such as a glass plate, for example, by a coating method, a dipping method,
Any known method such as a combination method of these may be used, and the amount of application and/or impregnation can be varied within a wide range depending on the purpose, such as about 5 to 3,000 g (compounded solution)/m''. .

The drying step in the method of the present invention can be completed in a very short time and without the need for complicated processing, and this drying process is the rate-limiting step in productivity in the dry method as in the method of the present invention. Therefore, such a short drying time is extremely advantageous compared to conventional methods. That is, the coated and/or impregnated substrate is removed by mere evaporation of the medium.

The desired porous sheet material of the present invention can be obtained without any special coagulation process, and only by drying at about 60 to 100°C for about 1 to 3 minutes and about 100 N at 150°C for about 1 to 3 minutes. . The reason why such a short drying process is achieved is that the dispersed polyurethane used as a film forming agent in the present invention occupies a considerable portion of the total polyurethane, and a relatively small amount of the dispersant (modified polyurethane) This is because polyurethane is stably dispersed in organic solvents, and during drying, as the good solvent in the organic solvent evaporates, the dispersed polyurethane easily comes into contact with poor solvents, causing gelation to occur quickly and easily. Conceivable.

Next, the present invention will be explained in more detail with reference to Examples. Note that parts or percentages in the text are based on weight.

Example 1 100 parts of itaconic acid and 95 parts of ethylene glycol were placed in a reaction vessel equipped with a dehydrator, stirred while blowing nitrogen gas, and heated to 140°C. Thereafter, the temperature was raised to 200°C while increasing the temperature by 30°C every hour. The dehydration polycondensation reaction was continued at that temperature, and the reaction was terminated when the acid value became 1 or less. The resulting unsaturated compound having active hydrogen at both ends had an acid value of 0.5 and an average molecular weight of 220.

Next, 100 parts of polytetramethylene glycol ether (average molecular weight about 2,000, hydroxyl value 56), 3 parts of the unsaturated compound having active hydrogen at both ends obtained by the above reaction, 16 parts of 4,4'-diphenylmethane diisocyanate and 100 parts of methyl ethyl ketone were placed in a reaction vessel and reacted at 75 to 85°C under a nitrogen stream, and diluted with methyl ethyl ketone as the viscosity increased to obtain a final polyurethane resin solution with a resin concentration of 30% and a viscosity of 12,000 cps/20°C. Ta.

Next, 5 parts of n-butyl methacrylate, 10 parts of 2-hydroxyethyl methacrylate, 0.2 parts of benzoyl peroxide, 25 parts of methyl ethyl ketone, and 40 parts of sec-butyl alcohol were added to 100 parts of this polyurethane resin solution, and 80 parts of The reaction was carried out at 85°C for 6 hours to obtain a modified polyurethane resin solution having a viscosity of 2.10Ocps, a viscosity of 725°C, and a solid content of 25%.

Example 2 100 parts of polyethylene glycol adibate glycol (average molecular weight approximately i, ooo, hydroxyl value 112), 4 parts of the unsaturated compound having active hydrogen at both ends obtained in Example 1, and 4.4'-diphenylmethane 30 parts of diisocyanate and 100 parts of methyl ethyl ketone are placed in a reaction vessel and reacted at 75 to 85°C under a nitrogen stream, and as the viscosity increases, diluted with methyl ethyl ketone to produce a final polyurethane resin with a resin concentration of 30%, a viscosity of 8.000 cpg, and a temperature of /20°C. A solution was obtained.

Next, polyoxyethylene glycol monomethacrylate (average molecular weight 3
00), 0.2 parts of benzoyl peroxide, and 28 parts of methyl ethyl ketone were added, and the reaction was carried out at 80 to 85°C for 6 hours in a nitrogen atmosphere, resulting in a viscosity of 3.500 c.
A modified polyurethane resin solution having a solid content of 30% was obtained at 730°C.

Example 3 100 parts of itaconic acid and 138 parts of 1,4-butanediol were placed in a reaction vessel equipped with a dehydrator, stirred while blowing nitrogen gas, and heated to 140°C. then 1
The temperature was raised to 200°C while increasing the temperature by 30°C every hour.

The dehydration polycondensation reaction was continued at that temperature, and the reaction was terminated when the acid value became 1 or less.

The obtained unsaturated compound having active hydrogen at both ends has an acid value of 0.4. The average molecular weight was 280.

Next, polyethylene glycol adipate glycol (
Average molecular weight approximately 2,000, hydroxyl value 56) 100 parts, 4 parts of the unsaturated compound having active hydrogen at both ends obtained by the above reaction, 17 parts of hydrogenated 4,4'-diphenylmethane diisocyanate, and 100 parts of methyl ethyl ketone. was placed in a reaction vessel, and while reacting at 80 to 85°C in a nitrogen atmosphere, o and i parts of dibutyltin dilaurate were added, and as the viscosity increased, it was diluted with methyl ethyl ketone.
Final resin concentration 30%, viscosity 22.000cps 7
A polyurethane resin solution at 20°C was obtained.

Next, 10 parts of 2-hydroxyethyl methacrylate, 5 parts of methacrylamide, 23 parts of methyl ethyl ketone, 40 parts of sec-butyl alcohol and 0.4 parts of azobisisobutyronitrile were added to 100 parts of this polyurethane resin solution, and in a nitrogen atmosphere. The reaction was carried out at 80 to 85°C for 7 hours to obtain a modified polyurethane resin solution having a viscosity of 2.600 cps, 725°C, and a solid content of 25%.

Example 4 Polytetramethane, 100 parts of lengelicol ether (average molecular weight approximately 2.000, hydroxyl value 56), 3 parts of the unsaturated compound having active hydrogen at both ends obtained from Example 3, 4,4'-diphenylmethane 16 parts of diincyanate and 100 parts of methyl ethyl ketone were placed in a reaction vessel,
The reaction was carried out at 75 to 85°C under a nitrogen stream, and as the viscosity increased, it was diluted with methyl ethyl ketone until the final resin concentration was 30%.
, a polyurethane resin solution with a viscosity of 12,000 cps/20°C was obtained.

Next, 12 parts of glycidyl methacrylate, 0.2 parts of benzoyl peroxide, and 28 parts of methyl ethyl ketone were added to 100 parts of this polyurethane resin solution, and a reaction was carried out at 80 to 85°C for 6 hours in a nitrogen atmosphere, resulting in a viscosity of 2.
, 600 cps/25° C., a modified polyurethane resin solution having a solid content of 30% was obtained.

Example 5 Polytetramethylene glycol (average molecular weight approximately 1.00
0, hydroxyl value 112), 1.000 parts of ethylene glycol, 93 parts of diphenylmethane diisocyanate, and 625 parts of methyl ethyl ketone i were added to 60°C.
After 8 hours of reaction.

Further, 1,077 parts of methyl ethyl ketone was added to obtain a polyurethane resin solution with solid content of 40%, viscosity i, and 200 poise/25°C.6 Next, this polyurethane resin solution 10
To 0 parts, 25 parts of the modified polyurethane resin solution obtained in Example 1 was added, and while stirring vigorously, a mixed solvent of 60 parts of isopropyl alcohol and 40 parts of water was gradually added and mixed until the solid content was 21%. , a dispersion (A) of the present invention having a viscosity of 90 cps/25° C. was obtained. The particles of this dispersion are O, O
It is a stable dispersion with a diameter of S~2 microns and no sedimentation.

Example 6 1.4-Butane ethylene adipate (average molecular weight approx. 1.
000, hydroxyl value 112) 1,000 parts, 1,4-butanediol 144 parts, methyl ethyl ketone 1.100 parts and diphenylmethane diisocyanate) 650 parts 7
After reacting for 8 hours at 0°C, 1,591 parts of methyl ethyl ketone was further added to homogenize the mixture, and the mixture was cooled to room temperature while stirring to obtain a polyurethane resin solution having a solidity of 40%, a viscosity of 1, 500 cps, and a temperature of 725°C.

Next, to 100 parts of this polyurethane resin solution, 20 parts of the modified polyurethane resin solution obtained in Example 2 was added, and while stirring vigorously, a mixed solvent of 60 parts of methyl alcohol and 40 parts of water was gradually added and mixed. Solid content 21%, viscosity 1
A dispersion (B) of the present invention was obtained at 10 cps/25°C.

The particles of this dispersion have a diameter of 0.02 to 34 m, and are a stable dispersion with no sedimentation.

Example 7 Instead of the modified polyurethane resin solution used in Example 6, the same amount of the modified polyurethane resin solution of Example 3 was used,
A polyurethane dispersion (C) of the present invention having properties similar to those in Example 6 was obtained in the same manner as in Example 6.

Example 8 Instead of the modified polyurethane resin solution used in Example 5, the same amount of the modified polyurethane resin solution of Example 4 was used,
A polyurethane dispersion (D) of the present invention having properties similar to those in Example 5 was obtained in the same manner as in Example 5.

Examples 9 to 12 The above polyurethane dispersions (A) to (D) were coated (or impregnated) on various base materials under the conditions listed in Table 1 below,
After drying, various porous sheet materials of the present invention listed in Table 2 below were obtained.

Example 9 Nine Tomb difference - AtJt Glass plate 'm 300 (coating) Rainbow i 70℃ 3 minutes + 100℃ 3 minutes Hot air drying Example 1 O minutes from L stop tJt Glass plate m4-00 (coating) Illusion u'' 8o, "03 minutes + lOO℃3 minutes hot air drying Example 11 Tray" L body - CLJi glass plate ゛・! Ll 300 (coating) 1
u" 70°C 3 minutes + 100°C 3 minutes Hot air drying Example 12 minutes" L body - DLJt Glass plate' m 400 (coating*)
(Hot air drying at 70°C for 3 minutes + 110°C for 3 minutes 2 sheets)
0.581 79 4800 118 3
30to O, 596115520056260
110,5398353001103E1012
0.591 130 5800 ・125 3
10 Notes ■... Apparent specific gravity (g/cm") II...Thickness IL) ■... Moisture permeability (g/rrf -24b) (JIS
20208B) IV... Strength (kg/crn') ■... Elongation (%) As described above, according to the method of the present invention, a porous sheet material with excellent physical properties can be obtained in an extremely short drying process. I can do it.

Patent applicant: Dainichiseika Industries Co., Ltd. 1 other person

Claims (1)

[Claims] (1) A mixed solvent consisting of an organic solvent, polyurethane dispersed in the organic solvent, and a dispersant, and a solvent that is a good solvent and a solvent that is a poor solvent for the polyurethane in which the organic solvent is dispersed; A modified polyurethane having a graft polymer chain in which the dispersant is a nonionic addition-polymerizable monomer, the graft polymer chain being solvated by the organic solvent,
A method for producing a porous sheet material, which comprises impregnating and/or coating a base material and drying the material.