JPH0114020B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a porous polyurethane sheet material and a method for producing the same, and aims to provide a porous sheet material with excellent mechanical properties, water vapor permeability, etc. with high productivity. purpose. (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. Examples of such a dry method include methods described in Japanese Patent Publication No. 55-18249 and Japanese Patent Application Laid-Open No. 51-41063,
In these conventional methods, because a relatively large amount of hydrophilic polyurethane is used to form the polyurethane layer, the mechanical properties, physical and chemical properties of the sheet material obtained are not sufficient, and the manufacturing method The cumbersome and time-consuming drying process is a decisive drawback. In order to solve these drawbacks, it is inevitable to reduce the amount of hydrophilic polyurethane used, but it is clear that this will lead to other drawbacks (for example, instability of the processing solution, etc.). It's summery. As a result of intensive research in order to solve the above-mentioned drawbacks of the prior art, the present inventor has made a hydrophobic polyurethane dispersion or solution based on a specific manufacturing method the main component of the coating material, while A small amount of hydrophilic modified polyurethane obtained by graft polymerizing a specific proportion of at least one type of ionic hydrophilic monomer selected from the group of addition-polymerizable monomers having a tertiary amino group or a quaternary ammonium group is used as an emulsifier. According to
The present invention was completed based on the finding that the above-mentioned drawbacks of the prior art can be solved. (Means for Solving the Problems) That is, the present invention provides a porous sheet material in which a porous layer consisting of a hydrophobic polyurethane (a) and a hydrophilic modified polyurethane (b) is provided on a base material; (a) is a hydrophobic polyol;
It is a hydrophobic polyurethane obtained by reacting an organic diisocyanate and a chain extender. and then graft polymerization with at least one ionic hydrophilic monomer selected from the group of addition polymerizable monomers having a carboxyl group, a sulfonic acid group, a tertiary amino group, or a quaternary ammonium group. The hydrophilic modified polyurethane (b) contains a hydrophilic addition-polymerizable monomer polymer.
A porous sheet material characterized by containing 10 to 50% by weight, and a method for producing the same. To explain the present invention in more detail, the hydrophobic polyurethane (a) used in the method of the present invention itself is a conceptually known material, and is obtained by reacting a hydrophobic polyol, an organic diisocyanate, and a chain extender. For example, as a hydrophobic polyol, the terminal group is a hydroxyl group and the molecular weight is
300-4000 polyethylene adipate, polyethylene propylene adipate, polyethylene butylene adipate, polydiethylene adipate, polybutylene adipate, polyethylene succinate, polybutylene succinate, polyethylene sebacate, polybutylene sebacate, polytetramethylene ether glycol, poly-ε -Caprolactone diol, polyhexaethylene adipate, carbonate polyol, polypropylene glycol, etc.; organic diisocyanates include 4,4'-diphenylmethane diisocyanate (MDI), water-added MDI, isophorone diisocyanate, and 1,3-xylylene diisocyanate. ,
1,4-xylylene diisocyanate, 2,4-
Tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-
Examples of chain extenders include phenylene diisocyanate, ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, ethylenediamine, 1,2-propylenediamine, trimethylenediamine, and tetramethylene. Examples include diamine, hexamethylene diamine, decamethylene diamine, isophorone diamine, m-xylylene diamine, hydrazine, and water. Hydrophobic polyurethane dispersions or solutions (e) have limited mutual solubility of polyurethane (a) with water;
Preferably, it can be obtained by reacting the above three components in an organic solvent (c) having a boiling point of 120° C. or lower at normal pressure. The reaction conditions, such as temperature and time, may be conventionally known conditions. Preferred organic solvents (c) 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, toluene, xylene,
dimethylformamide, dimethyl sulfoxide,
Perchlorethylene, trichlorethylene, methyl cellosolve, butyl cellosolve, cellosolve acetate, etc. can also be used. Those that have limited mutual solubility with water in these organic solvents, or those that do not dissolve at all, should be mixed with other solvents,
Used with limits on mutual solubility with water. Of course, the above solvents can also be used as a mixed solvent. Polyurethane(a) in organic solvents such as
A dispersion or solution (e) is obtained by preparing a dispersion or solution (e) whose solids content is advantageously in the range from about 5 to 60% by weight by addition or removal of the same or other solvents. The modified polyurethane (b) used in the present invention is at least one ionic hydrophilic monomer selected from the group of addition polymerizable monomers having a carboxyl group, a sulfonic acid group, a tertiary amino group, or a quaternary ammonium group. A graft polymer consisting of
It may contain 10 to 50% by weight and be dissolved in the organic solvent (c). Such modified polyurethane (b)
is to react the above-mentioned hydrophobic polyol and the above-mentioned organic diisocyanate to the presence of a chain extender having an unsaturated double bond in the same manner as polyurethane (a), and then to graft-polymerize a hydrophilic addition-polymerizable monomer. It is obtained by The above-mentioned chain extender to be used has an average molecular weight of about 140 to 140, in which part or all of the chain extender is obtained by dehydration condensation of an unsaturated dibasic acid and a bifunctional compound having active hydrogen.
1000 is preferably an unsaturated compound having active hydrogen at both ends (hereinafter referred to as a specific chain extender), and this specific chain extender is an unsaturated compound such as itaconic acid, fumaric acid, maleic anhydride, citraconic acid, etc. Saturated dibasic acids or their functional derivatives, etc., diamines such as hydrazine, ethylenediamine, piperazine, propylene diamine, xylylene diamine, isophorone diamine, ethylene glycol,
Glycols such as 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, propylene glycol, diethylene glycol, 1,5-pentanediol, neopentyl glycol, dipropylene glycol, monoethanolamine, dimethyl difunctional compounds having active hydrogen, such as amine alcohols such as ethanolamine, and about 1.2 to 2.0 per mole of unsaturated dibasic acid.
It is obtained by polycondensation in a molar ratio,
Particularly preferred are those with an average molecular weight of about 140.
~1000 things. 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,
The time reaction conditions are favorable. Such specific chain extenders are used in the method of the present invention for hydrophobic polyol 1
It is used in a ratio of 0.001 to 0.5 mole to mole. This particular chain extender can also be used in combination with other common chain extenders, such as water and bifunctional compounds containing active hydrogen as described above. The ionic hydrophilic monomer used in the present invention is
Any of them may be publicly known, such as acrylic acid, methacrylic acid, α-chloroacrylic acid, α-
Chlormethacrylic acid, maleic acid, itaconic acid,
Vinyl sulfonic acid, sulfonated styrene, 2-acrylamido-2-methylpropanesulfonic acid,
Preferred are nitrogen-containing vinyl monomers such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, vinylpyridine, vinylnaphthalene, or quaternized products thereof. Further, other addition polymerizable monomers may be used in combination to adjust the balance between hydrophilicity and hydrophobicity. For example, acrylic acid, α-chloroacrylic acid,
Methacrylic acid, methyl, ethyl, propyl, butyl esters thereof; styrene, methylstyrene, dimethylstyrene, ethylstyrene, methoxystyrene, divinylbenzene, α-methylstyrene, β-methylstyrene, chlorstyrene,
2,5-dichlorostyrene, α-chlorostyrene or derivatives thereof are preferred.
Furthermore, in order to increase the stability of the polyurethane emulsion (d), it is also possible to use a combination of the modified polyurethane (b) and a general w/o type emulsifier. The above-mentioned modified polyurethane (b) is mixed with the above-mentioned polyurethane dispersion or solution (e) as a solution in an organic solvent or alone, and used as it is or after being neutralized. This mixed dispersion or solution consists of polyurethane(a)
is in a dispersed state or a solution, and the modified polyurethane (b) is in a dissolved state, and the total solid content is about 5 to 60% by weight. The polyurethane emulsion (d) used in the present invention is obtained by stirring the above mixed dispersion or solution with strong stirring.
This can be obtained by adding a saturated amount or less of water, for example, about 50 to 500 parts by weight of water per 100 parts by weight of solids in the mixed dispersion or solution. The emulsion thus obtained is a milky white creamy fluid and remains stable even if left as is for several months. Various additives such as colorants, crosslinking agents, stabilizers, fillers, and other known additives can be optionally added to such emulsions as required. The base material used in the present invention may be any base material such as various woven fabrics, knitted fabrics, non-woven fabrics, release papers, plastic films, metal plates, glass plates, etc. The emulsion may be applied to the substrate by any known method such as a coating method, a dipping method, or a combination thereof, and the amount of application and/or impregnation is approximately 5 to 2000 g (blended solution)/ ^m2
It can be varied within a wide range depending on the purpose. 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. hand,
Such short drying time is extremely advantageous compared to conventional methods. That is, the coated and/or impregnated substrate does not require any coagulation process as described in JP-A-51-41063,
About 1 to 3 minutes at 100℃ and about 1 minute at about 100 to 150℃
The desired porous sheet material of the present invention can be obtained by only drying for ~3 minutes. Such a short drying process is achieved because the hydrophobic polyurethane (a) used as a film forming agent in the present invention accounts for most of the total polyurethane, and a small amount of surfactant (polyurethane ( This is thought to be because b)) is stably dispersed and emulsified with water, and when drying, it quickly and easily comes into contact with water due to evaporation of the organic solvent, resulting in gelation. (Function/Effect) The porous sheet material obtained by the present invention as described above has a very fine pore structure, has excellent physical properties, and has excellent water vapor permeability, and can be used for various synthetic leathers, etc. It is useful as a material for clothing, shoes, waterproof fabrics, tents, wallpaper, flooring materials, filtration materials, filters for air conditioners, etc. Next, the present invention will be specifically explained with reference to Examples. Note that all ``%'' and ``%'' in the text are based on weight. Examples 1 to 7 (Production of hydrophobic and hydrophilic polyurethane) 1 1000 parts of polytetramethylene glycol (average molecular weight approximately 1000, hydroxyl value 112), 93 parts ethylene glycol, and 625 g diphenylmethane diisocyanate were added to 1500 parts methyl ethyl ketone. ,
After reacting at 60°C for 8 hours, 2500 parts of methyl ethyl ketone was added and cooled to room temperature with stirring to form a milky white polyurethane dispersion with a solid content of 30%.
I got (1). 2 1,4-butane ethylene adipate (average molecular weight approximately 1000, hydroxyl value 112) 1000 parts, 1,4-
144 parts of butanediol, methyl ethyl ketone
After reacting 1,144 parts of diphenylmethane diisocyanate and 650 parts of diphenylmethane diisocyanate for 8 hours at 70°C, 3,042 parts of methyl ethyl ketone was added to homogenize the mixture, and the mixture was cooled to room temperature while stirring to form a milky white polyurethane dispersion (2) with a solid content of 30%. I got it. 3 Add 1000 parts of 1,6-hexamethylene adipate (average molecular weight 2000, hydroxyl value 56), 125 parts of 1,4-butanediol, and 472 parts of diphenylmethane diisocyanate to 1200 parts of methyl ethyl ketone, and react at 70°C for 8 hours. Then, 2,526 parts of methyl ethyl ketone was added to homogenize the mixture, and the mixture was cooled to room temperature while stirring to obtain a milky white polyurethane dispersion (3) with a solid content of 30%. 4 After reacting 1000 parts of 1,4-butane ethylene adipate (average molecular weight approximately 1000, hydroxyl value 112) and 408 parts of isophorone diisocyanate at 100°C for 6 hours, 1230 parts of methyl ethyl ketone and 1230 parts of toluene were added.
1,230 parts of 2-butanol, and 148 parts of isophorone diamine were added, and the mixture was thoroughly homogenized by stirring to obtain a polyurethane solution (4) with a solid content of 30%. 5. 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. After that, the temperature was increased by 30℃ every hour.
The temperature was raised to 200℃. 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 approximately 2000, 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 under a nitrogen stream.
React at 75-85℃, dilute with methyl ethyl ketone as the viscosity increases, and finally reduce the resin concentration to 30.
%, and a viscosity of 12000 cps/20°C was obtained. Next, add 100 parts of this polyurethane resin solution to
5 parts of n-butyl methacrylate, 15 parts of dimethylaminoethyl methacrylate, 50 parts of methyl ethyl ketone, 30 parts of sec-butyl alcohol and 0.2 parts of benzoyl peroxide were added and reacted for 6 hours at 80-85°C in a nitrogen atmosphere.
A modified polyurethane resin solution (5) with a solid content of 25% was obtained at 2600 cps/25°C. 6 100 parts of polyethylene glycol adipate glycol (average molecular weight approximately 1000, hydroxyl value 112), 4 parts of the unsaturated compound having active hydrogen at both ends obtained in Example 5, and 30 parts of 4,4'-diphenylmethane diisocyanate. and 100 parts of methyl ethyl ketone in a reaction vessel, and under a nitrogen stream
React at 75-85℃, dilute with methyl ethyl ketone as the viscosity increases, and finally reduce the resin concentration to 30.
%, and a viscosity of 8000 cps/20°C was obtained. Next, add 100 parts of this polyurethane resin solution to
5 parts of methacrylic acid, 2-acrylamide-2-
5 parts of methylpropanesulfonic acid, 26 parts of methyl ethyl ketone, 24 parts of sec-butyl alcohol and 0.2 parts of benzoyl peroxide were added, and the reaction was carried out at 80 to 85°C for 6 hours in a nitrogen atmosphere.
A modified polyurethane resin solution (6) with a solid content of 25% was obtained at 3900 cps/25°C. 7 100 parts of itaconic acid and 1,4-butanediol
Put 138 parts into a reaction vessel equipped with a dehydrator,
Stir while blowing nitrogen gas to 140℃
The temperature rose to 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 0.4 and an average molecular weight of 280. Next, 100 parts of polytetramethylene glycol ether (average molecular weight approximately 2000, hydroxyl value 56),
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 were placed in a reaction vessel at 80 to 85°C in a nitrogen atmosphere. While the reaction was being carried out, 0.1 part of dibutyltin dilaurate was added, and as the viscosity increased, it was diluted with methyl ethyl ketone to finally obtain a polyurethane resin solution with a resin concentration of 30% and a viscosity of 2000 cps/20°C. Next, add 100 parts of this polyurethane resin solution to
10 parts ethyl methacrylate, 10 parts methacrylic acid
1 part, 65 parts of methyl ethyl ketone, 15 parts of isopropyl alcohol, and 0.4 part of azobisisobutyronitrile, and the mixture was heated at 80 to 85°C in a nitrogen atmosphere for 7 hours.
The reaction was carried out for a period of time to obtain a modified polyurethane resin solution (7) with a viscosity of 1200 cps/25°C and a solid content of 25%. Examples 8 to 13 (Production of polyurethane emulsion) The products of Examples 1 to 7, organic solvent and water were stirred in a homomixer, and the following polyurethane w/o
An emulsion was prepared. 8 Polyurethane emulsion (8) Polyurethane dispersion (1) 100 parts polyurethane solution (5) 10 parts methyl ethyl ketone 20 parts toluene 20 parts water 80 parts 9 Polyurethane emulsion (9) Polyurethane dispersion (2) 100 parts polyurethane solution (5) 12 parts dioxane 10 parts toluene 10 parts xylene 20 parts water 60 parts 10 Polyurethane emulsion (10) Polyurethane dispersion (2) 100 parts polyurethane solution (6) 7 parts methyl ethyl ketone 20 parts xylol 20 parts water 75 parts 11 Polyurethane emulsion (11) Polyurethane dispersion (3) 100 parts polyurethane solution (6) 5 parts tetrahydrofuran 20 parts xylene 20 parts water 80 parts 12 Polyurethane emulsion (12) Polyurethane dispersion (3) 100 parts polyurethane solution ( 7) 12 parts Methyl ethyl ketone 150 parts Methyl isobutyl ketone 20 parts Water 70 parts 13 Polyurethane emulsion (13) Polyurethane solution (4) 100 parts Polyurethane solution (5) 10 parts Calcium carbonate 10 parts Toluene 30 parts Methyl ethyl ketone 20 parts Water 80 parts The properties of the polyurethane emulsions (8) to (13) are shown in Table 1 below.

[Table] Examples 14 to 20 The polyurethane emulsions (8) to (13) shown in Table 1 above are applied (or impregnated) onto various substrates and dried to form various porous sheet materials of the present invention. Obtained. Table 2 (manufacturing conditions) Example 14 Emulsion 8 Base material Release paper coating (impregnation) amount (g/m ² ) 200 (coating) Drying conditions 80℃ 2 minutes + 125℃ 2 minutes Example 15 Emulsion 8 Base material Nylon taffeta coating (impregnation) amount (g/m ² ) 600 (coating) Drying conditions 80℃ 2 minutes + 125℃ 2 minutes Example 16 Emulsion 9 Base material Cotton cloth coating (impregnation) amount (g/m ² ) 400 (coating) Drying conditions 80℃ 2 minutes + 125℃ 2 minutes Example 17 Emulsion 10 Base material T/R napping fabric coating (impregnation) amount (g/m ² ) 800 (coating) Drying conditions 80℃ 3 minutes + 140 Example 18 Emulsion 11 Base material Cotton fabric coating (impregnation) amount (g/m ² ) 300 (coating) Drying conditions 80℃ 2 minutes + 125℃ 2 minutes Example 19 Emulsion 12 Base material Non-woven fabric coating ( Impregnation) amount (g/m ² ) 1000 (coating) Drying conditions 90℃ 3 minutes + 140℃ 3 minutes Example 20 Emulsion 13 Base material Tetron taffeta coating (impregnation) amount (g/m ² ) 100 (coating) Drying Conditions 80℃ 2 minutes + 125℃ 2 minutes

【table】

[Table] 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.

Claims (1)

[Scope of Claims] 1. A porous sheet material in which a porous layer consisting of a hydrophobic polyurethane (a) and a hydrophilic modified polyurethane (b) is provided on a base material; A hydrophobic polyurethane obtained by reacting a polyol, an organic diisocyanate, and a chain extender. and then graft polymerization with at least one ionic hydrophilic monomer selected from the group of addition polymerizable monomers having a carboxyl group, a sulfonic acid group, a tertiary amino group, or a quaternary ammonium group. 1. A porous sheet material, wherein the hydrophilic modified polyurethane (b) contains 10 to 50% by weight of a hydrophilic addition-polymerizable monomer polymer. 2 A water-in-oil polyurethane emulsion (d) consisting of hydrophobic polyurethane (a), hydrophilic modified polyurethane (b), organic solvent (c) and water is impregnated and/or applied to a base material, and dried. In a method for producing a porous sheet material, the hydrophobic polyurethane (a) contains a hydrophobic polyol, an organic diisocyanate, and a chain extender in an organic solvent (c) having limited mutual solubility with water. A hydrophobic polyurethane dispersion or solution (e) obtained by reacting the hydrophilic modified polyurethane (b) with a hydrophobic polyol and an organic diisocyanate in the presence of a chain extender having an unsaturated double bond. and then graft polymerization with at least one ionic hydrophilic monomer selected from the group of addition polymerizable monomers having a carboxyl group, a sulfonic acid group, a tertiary amino group, or a quaternary ammonium group. A method for producing a porous sheet material, wherein the hydrophilic modified polyurethane (b) contains 10 to 50% by weight of a hydrophilic addition-polymerizable monomer polymer. 3. The chain extender having an unsaturated double bond has an average molecular weight of about 140 to
The manufacturing method according to claim 2, which comprises an unsaturated compound having active hydrogen at both ends of 1,000.