JPS602782A - Manufacture of leathery sheet - Google Patents

Abstract

PURPOSE:To obtain the titled sheet having sufficient flexibility and nerve, by modifying the fiber surface of a fibrous base cloth with a specific treating agent, and impregnating and/or coating the cloth with a water-containing slurry composed of a specific polyurethane composition. CONSTITUTION:A fibrous base cloth pretreated with a treating liquid composed mainly of colloidal silica is impregnated and/or coated with a water-containing slurry obtained by (1) reacting a long-chain glycol having an average molecular weight of 500-5,000, an organic diisocyanate and a low-molecular diol at <=120 deg.C in an organic solvent (e.g. methyl ethyl ketone) which dissolves 1-50g of water per 100g, and (2) adding 10-95wt%, based on the critical water-content (the critical amount of water to break the emulsion), of water to the obtained solution or slurry of a polyurethane. The organic solvent is evaporated, and the residue is gelatinized and dried to obtain the objective sheet. A sufficiently high nerve can be attained by mixing the slurry with a surface active agent composed of a hydrophobic component selected from polyalkylene oxides, etc. other than ethylene oxide and a hydrophilic component composed mainly of polyethylene oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for producing leather-like sheets. The present invention relates to a method for producing a leather-like sheet material having good flexibility and stiffness and made of cloth and a specific polyurethane composition.

BACKGROUND OF THE INVENTION A method for producing a leather-like sheet material using dry microporous polyurethane technology is known as shown in U.S. Pat. No. 3,666,542 and U.S. Pat. No. 3,895,134. In addition, Ili fiber surface modifier for fibrous base fabric,
Pluronic surfactant shown in Japanese Patent Application No. 50-138752, Q:j Copolymerized polyester obtained from polyalkylene needle, low-molecular mother diol, and dicarboxylic acid or its ester shown in Japanese Patent Application No. 50-105876. It is known that a water-repellent silicone is used as a fiber surface modifier for the fiber base material 5 to obtain a flexible leather-like material. This is also known.

It is easy to produce 1q of iIC flexible leather-like sheet materials by combining the known dry porous polyurethane technology and the fiber surface modifier for the fibrous base fabric. However, the C flexibility cannot be obtained by the following method, but the stiffness peculiar to natural leather cannot be obtained, and when worn as footwear as a leather substitute, the appearance is insufficient for one person to wear. Some shortcomings have been pointed out.

Purpose The present inventor has arrived at the present invention as a result of intensive research into a method for producing a leather-like sheet material that has sufficient flexibility and sufficient stiffness found in natural leather.

The constitution of the invention, that is, the present invention, has a boiling point of 120°C or less and 100g
An organic solvent that dissolves 1 to 5 J of water per water (in a >
Long chain glycol with average molecular weight 500-5,000, right (
A solution or slurry of polyurethane obtained by reacting a cyclic diisocyanate and a low-molecular diol, and 10 to 95 weight ω% of the amount of critical water added to the solution or slurry.
water is added and mixed to form a water-containing slurry, and the water-containing slurry is impregnated and/or coated on a fibrous base fabric treated with a treatment liquid containing colloidal silicate as a main component. This is a method for producing a leather-like sheet material, which comprises selectively evaporating an organic solvent (a) to gel it, and then drying it.

Organic solvent (a) for polyurethane used in the present invention
(a) The boiling point must be 120°C or lower (o) It must satisfy the conditions (a) and (0) to dissolve 1 to 5 Jj of water per 100g.

When an organic solvent with a boiling point exceeding 120°C is used, it is difficult to selectively evaporate the organic solvent from the water-containing slurry, and as a result, the microporous polyurethane targeted by the present invention cannot be obtained. Also, 1 to 50 per 100g
If the organic solvent is not one that can dissolve VE of water in VE, a stable water-containing slurry cannot be obtained and the object of the present invention cannot be achieved.

Examples of organic solvents (a) that satisfy the above requirements (a) and (0) include methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methylforme-1, and n-propyl ketone. Bill for No 1~. Methyl acetate-1~, ethyl aretate, isopropyl aretate, isobutyl acetate-1-,
Examples include 5ea-butyl acetate and 1,2-dichloroethane. Mixed solvents of two or more of these solvents can also be used since they can satisfy the above requirements (a) and (○). In addition, organic solvents 1 having high solubility in water, such as acetone,
Organic solvents that hardly dissolve water, such as hydrofuran or dioxane, etc.0, such as benzene, toluene, or n
- It is also possible to use a mixed organic solvent adjusted to satisfy the above requirements (a) and (0) by mixing it with hegisan or the like.

The long chain glycols used in the present invention include polyesters,
Polyethers can be used, such as polyethylene adipate and polybutylene adipate.

Polyethylene propylene adipate, polyethylene butylene adipate, polydiethylene adipate, polyethylene succinate, polybutylene succinate, polytetramethylene glycol, polypropylene glycol,
Examples include polyoxyethylene glycol, which has a molecular weight of 500 to 5,0 due to the characteristics of polyurethane.
00 is appropriate.

It is also possible to mix the above-mentioned glycols as long-chain glycols, and in particular, by using a mixture of hydrophobic glycol and polyoxyethylene glycol, when forming the water-containing slurry described later, it increases its stability and is advantageous in forming porous structures. , particularly preferred. At this time, the polyoxyethylene glycol is 1 to 15% by weight based on the weight of the polyurethane composition.
A range of is preferred for that purpose.

Examples of the organic diisocyanate include 4,4'-diphenylmethane diisocyane-1-1, 1,3-xylene diisocyane 1-1, and 1,4-xylene diisocyane I.
~, 2. l toluene diisocyanate.

2, i + -lene diisocyanate, 1,5-naphthylene diisocyanate 1-,1,5-naphthylene diisocyanate l-, m-phenylene diisocyanate.

Examples include p-phenylene diisocyanate-1, hexamethylene diisocyanate-1, and 4,4'-dicyclohexylmethane diisocyanate-1.

As the low-molecular diol used as a chain extender, any one used as a raw material for polyurethane can be used, such as ethylene glycol, propylene glycol,
1.3-Propanediol.

Diethylene glycol, triethylene glycol.

1,4-butanediol, 1,6-hexynanediol.

1, IL-; 4ctanesil, 1.10-decanediol.

Examples include N-methyljetanolamine and diodiethanol.

The above-mentioned polymerization method using long-chain glycol, organic diisocyanate, and low-molecular-weight diol can be carried out by either the prepolymer reaction-chain extension reaction method or the one-shot method. Either reaction or reaction in an organic solvent (a) may be used. However, in the case of chain extension reaction or one-shot reaction, an organic solvent (a
) must be done inside.

Add the critical water into the polyurethane solution or slurry obtained by polymerization as described above while stirring.
~95% by weight of water is added to form a water-containing slurry that is a creamy W10 type emulsion. The critical water addition amount referred to here means that when water is added to and mixed with a polyurethane solution or slurry whose temperature has been adjusted, the water is first solubilized in an organic solvent (a) called Solvent C, and then water is further added and mixed. Then, a W10 type emulsion is formed, and when water is further added and mixed, the W10 type emulsion is broken and water is separated. The amount of water added at which this W10 type emulsion is broken is called the critical amount of water added. Therefore, if water is added in an amount exceeding 95% by weight of the critical water addition amount, a stable water-containing slurry cannot be obtained, and if water is added in an amount less than 10% by weight of the critical water addition amount, it is difficult to obtain a stable water-containing slurry. Unable to obtain porous polyurethane,
A leather-like sheet material having the excellent properties found in natural leather cannot be obtained.

The water-containing slurry obtained as described above is impregnated and/or coated on a fibrous base fabric such as a non-woven fabric or a woven fabric, but in the present invention, these fibrous base fabrics are pre-contained with colloidal silica as a main component. d5 <
By doing so, a leather-like sheet material having sufficient flexibility and sufficient stiffness can be obtained.

The reason for this is that the affinity is determined by an appropriate balance between the water held in the water-containing slurry used as the impregnation liquid and the hydrophilic power of the colloidal silica treated on the fiber surface of the fibrous base fabric. This is thought to be due to the fact that silica has an affinity for polyurethane in the water-containing slurry. In other words, a portion of the water dispersed in the hydrophilic slurry forms a water film at the interface between the hydrophilic slurry impregnated with rhoidal silica and the dark blue surface of the IIM base fabric. It is thought that this water film prevents adhesion between the polyurethane and the fibrous base fabric, resulting in sufficient flexibility. Although such a phenomenon occurs with hydrophilic fiber surface modifiers or water-repellent silicones other than those of the present invention, the feature of the present invention is that the organic solvent (a) of the water-containing slurry impregnated into the fibrous base fabric is During the selective evaporation stage, the impregnated water-containing slurry gradually gels while retaining dispersed water, and polyurethane tends to form blocks due to large shrinkage force.
Polyurethane is retained on the fiber surface by colloidal silica, which has an affinity for the polyurethane treated on the fiber surface, and compared to the conventional fiber treatment agents mentioned above, it is less likely to block, resulting in sufficient stiffness. The goal is to provide a structure with a certain level of strength.

By the affinity balance principle of the water-containing slurry and the fiber surface modifier described above, it is possible to obtain a leather-like sheet-like material having sufficient flexibility and sufficient stiffness, which is the object of the present invention.

In order to achieve the above effects, the appropriate amount of colloidal silica to be applied to the fibrous base fabric as an active ingredient is 0.00% based on the weight of the fibers.
2-10.0%, preferably 0.5-6.0%C
be. If the treatment amount is less than 0.2%, the effect of using the above fiber surface modifier as a fiber surface modifier cannot be obtained due to the small amount of particles. 9fil! ! If the amount exceeds 6.0%, the above-mentioned effect as a fiber surface modifier can be obtained, but the treatment amount is too large and the colloidal silica falls off from the fiber surface, which is inappropriate.

In order to further enhance the above effects, in the water-containing slurry,
Polyalkylene oxide other than polyethylene oxide,
Consisting of a hydrophobic component mainly consisting of a compound selected from the group consisting of aliphatic polyesters and mixtures thereof and a hydrophilic component mainly consisting of polyethylene oxide, both components are substantially bonded by urethane bonds and/or amide bonds. A surfactant having a molecular weight of 2.5, in which the hydrophilic component accounts for 30 to 30% by weight of the entire surfactant.
0.00 to 30,000 parts of surfactant can be added and mixed in an amount of 0.2 to 10.0 parts per 100 parts of polyurethane in the water-containing slurry. By adding this surfactant to the water-containing slurry, a part of this surfactant is dissolved into the water film in the above principle explanation, and the water containing this surfactant is dissolved. Through the membrane, the polyurethane in the gelation process shows a stronger affinity with the fibers treated with C by rhoidal silica, and the polyurethane gels without becoming blocked, resulting in sufficient stiffness. J
It is thought that this gives a structure that

Examples of polyalkylene oxides other than polyethylene oxide constituting this surfactant have a molecular weight of 1 to 5.
00 to 6,000 polypropylene ether glycol, polytetramethylene ether glycol, bisphenol A propylene oxytoy, trimethylolpropane propylene oxytoy, or pentaerythritol propylene oxide adduct. It will be done. Examples of aliphatic polyesters include those with a molecular weight of 1.5
00-6. Examples include OQO's polyethylene adipate, polybutylene adipate, and polyhexamethylene adipate. The above-mentioned hydrophobic polyols alone or in combination as a hydrophilic component, preferably having a molecular weight of 800 to 800.
6,000 polyoxyethylene glycol combined with paid diisocyanate and has a molecular weight of 2.500 to 3.
0,000 is the surfactant bonded by the urethane bond of the present invention. The surfactant bonded by an amide bond is obtained by reacting the polyethylene oxide with an organic diisocyanate 1 to 1 to form a terminal isocyanate and bonding it to the terminal carboxylic acid group of the aliphatic polyester, or by reacting the polyethylene oxide with a hydrophobic polyester. Examples include those in which alkylene oxide is bonded to urethane using an organic diisocyanate, and the terminal isocyanate is reacted with the terminal carboxone mE4 of the aliphatic polyester. Alternatively, the surfactant bonded by an amide bond of the present invention can also be obtained by reacting a compound having a terminal amino group obtained by reacting the aliphatic polyester with an organic diamine with chloraledel polyethylene oxide. The above is just one example, and the surfactant of the present invention can be obtained by other conventionally known methods.

In this surfactant, the hydrophilic component accounts for 30 to 80% by weight of the entire surfactant, and the remaining 70 to 20% by weight.
is occupied by the hydrophobic component and all urethane bonds J3 and/or the amide bond and all bonding residues 31. If 30% by weight of the hydrophilic component is not swirled, the effect of strengthening the affinity between the polyurethane and the fiber surface in the gelling process of the present invention cannot be obtained. If the hydrophilic component exceeds 80% by weight, the water-containing slurry, which is a W10 type emulsion, is
7, so it is inappropriate. The molecular weight of the surfactant is 2.5
00-30,000, preferably 3,500-25,0
It is 00. If the molecular ω is less than 2,500, it is unsuitable because the surfactant tends to bleed onto the surface of the polyurethane product in the presence of heat or organic solvents. If the molecular weight exceeds 30,000, the melting point of the surfactant is too high and the surfactant tends to crystallize and separate and precipitate in the water-containing slurry, which is unsuitable.

The amount of surfactant to be added and mixed in a water-containing slurry is 0.2 to 1 per 100 parts of polyurethane in a water-containing slurry.
It is 0.0 part, preferably 0.5 to 6.0 parts.

In the case of 0.2 part H; 61, the effect of strengthening the affinity between the polyurethane and the fiber surface during the gelling process of the present invention cannot be obtained. If it exceeds 10.0 parts, it is unsuitable because the surfactant tends to bleed and the physical properties of the polyurethane deteriorate.

The fibrous base fabric impregnated with the water-containing slurry as described above is coated with the water-containing slurry, if necessary, and then placed in an atmosphere where the temperature and humidity are adjusted. After selectively evaporating the solvent (a) to prevent the polyurethane constituting the water-containing slurry from coagulating while retaining the dispersion water, the dispersion water is dried. When the temperature during evaporation is set below the boiling point of the organic solvent <a) and the humidity is high, selective evaporation of the solvent (a) in Section 11 can be carried out more selectively and faster.

As described above, the leather-like material has sufficient flexibility and sufficient strength, but in order to obtain even more flexibility, it is impregnated with a water-containing slurry. It is effective to selectively evaporate the organic solvent (a) by immersing the fibrous base fabric in water for 1 minute or more before selectively evaporating the organic solvent (a). This is because the water film formed at the interface between the impregnated water-containing slurry and the fiber surface of the fibrous base fabric is not only water in the water-containing slurry, but also water immersed in water. By external l
) This is thought to be because the amount of water supplied by X is increased, resulting in a larger distance between the fibers and the polyurethane, increasing the degree of freedom of the fibers. If the immersion time in water is less than 1 minute, the external water will penetrate into the inside of the impregnated fibrous base fabric! ! However, the effect cannot be improved by 1"J, which is inappropriate.

As explained above, according to the present invention, it is possible to obtain a seat-like sheet-like article having good flexibility and good waist strength that have never been seen before.

Example The present invention will be specifically explained below with reference to Examples.

All parts in the examples indicate parts by weight. Note that the characteristics in the present invention were measured as follows.

(1) Bending resistance Re When a 2 cm section of one end of a 2.5 cm wide x 9 cm long specimen is held and bent into a 2 cm 1/4 semicircle with a radius of curvature at a position 2 cm from the 411 seat. The repulsive force is measured and converted into a value for a −C width of 1 cm.

(2) Bending compressive stress P5 A test piece of width 2.5 cm x length 9 cm was bent in half, compressed until the thickness of the curved part became 5711/711, and the stress of the short was measured. The value is converted to a value with a width of 1 cm.

(3) Leather-like properties It is expressed as the value obtained by dividing the bending compressive stress P5 by the bending resistance RB, and the larger this value is, the more the drawing characteristics are typical of natural leather.

Example 1 (1) Preparation of polyurethane solution Polybutylene adipate with an average molecular direction of 185G 450
820 parts of methyl ethyl ketone are added to the terminal isocyanate prepolymer obtained from 40 parts of polyoxyethylene glycol with an average molecular i of 1540 and 390 parts of p,p'-diphenylmethane diisocyanate, and then dissolved in 80 parts of 1,4-butanediol. 1 part and 40 parts of diethylene glycol were added and reacted at 70°C with stirring, and as the viscosity increased, 3180 parts of methyl ethyl ketone was gradually added to obtain a polyurethane-methyl ethyl ketone solution with a final concentration of 20 parts.

In addition, the critical water addition m of this solution was 39 parts per 100 parts of this solution.

(2) Creation of water-containing slurry Into 1,000 parts of the above 20 parts polyurethane solution,
While stirring, 300 parts of water was added to obtain a creamy water-containing slurry.

(Processing weight for 31m surface quality base fabric: 4505J/Td, Thickness: 1.7IrL/m,
Non-woven fabric made of polyester fiber with 0.5% active ingredient
Concentrated colloidal silica (Snowtex manufactured by Nissei Kagaku)
20) Immerse in an aqueous solution, then squeeze uniformly with a nip roll so that the amount of treated liquid-containing nonwoven fabric becomes 13509/rIL, and then dry it in a hot air dryer for 130° CIO to remove the colloidal silica active ingredient from the nonwoven fabric. To 1.0 vs. lfL m ff! % (; J Arrival, : .

(4) The water-containing slurry was impregnated into the nonwoven fabric treated with rhoidal silica, left in an atmosphere of 0°C and 60% relative humidity for 25 minutes, and then placed in a hot air dryer at 130°C for 10 minutes. and dried. The obtained sheet-like material had good flexibility and stiffness, and was used as a substitute for natural leather, and the properties of C were unprecedented. Table 1 shows this characteristic.
Shown below.

(5) Coating (4) Impregnation C' The surface of the obtained sheet 1~ was coated with the water-containing slurry to a thickness of 1 m/m, and heated at a temperature of 45°C.
After being left in an atmosphere of 70% relative humidity for 40 minutes, 13
It was dried in a hot air dryer at 0°C for 10 minutes. The obtained sheet-like material had a smooth surface and had good flexibility and stiffness, and its properties as a natural leather substitute were unprecedented. This characteristic is shown in Table-1.

Example 2 (1) Creation of polyurethane solution Polyurethane solution with average molecular weight fi1856-1-490
820 parts of methyl ethyl ketone is added to and dissolved in the terminal isocyanate prepolymer obtained from 390 parts, and then 80 parts of 1,4-butanediol and 40 parts of diethylene glycol are added. was added and reacted at 70°C with stirring, and as the viscosity increased, 3180 parts of methyl ethyl ketone was gradually added to obtain a polyurethane-methyl ethyl ketone solution with a final concentration of 20 parts. 32 parts per 100 parts.

(2) Preparation of water-containing slurry 280 parts of water was added to 811,000 parts of the 20-part polyurethane solution with stirring to obtain a creamy water-containing slurry.

(3) Impregnation After the nonwoven fabric treated with colloidal silica obtained in Example 1 was impregnated with the water-containing slurry, the temperature was 0°C.
After being left in an atmosphere with relative humidity of 60% for 25 minutes, 13
It was dried in a hot air dryer at 0°C for 10 minutes. The obtained sheet-like material had good flexibility and stiffness, and these properties are shown in Table 1.

Example 3 "Roidal silica-untreated nonwoven fabric of Example 1 (450 g
/i) was immersed in an aqueous solution of rhoidal silica (Snowtex 20 manufactured by Nissho Chemical Co., Ltd.) with a concentration of 3.0% of the active ingredient, and then the treatment liquid-containing nonwoven fabric was coated with a nip roll for 1350y.
After squeezing it uniformly so that it becomes /i, it is heated to 10
The nonwoven fabric was dried in a hot air dryer for 6.0 minutes to coat the active ingredient of colloidal silica in an amount of 6.0% by weight of the fibers. This nonwoven fabric was impregnated with the water-containing slurry obtained in Example 1 and left for 25 minutes in an atmosphere at a temperature of 0°C and a relative humidity of 60%, and then dried in a hot air dryer at 130°C for 10 minutes. The obtained sheet-like material had good flexibility and stiffness.

This characteristic is shown in Table-1.

Comparative Example-1 Nonwoven li (45
0SF/11L) at a concentration of 0.05 part of the active ingredient.
” Idal silica (Snowtex 20 manufactured by Nissho Chemical Co., Ltd.) was immersed in an aqueous solution, then squeezed uniformly with nip rolls so that the treated solution-containing nonwoven fabric matrix was 1350 g/'rIL, and then dried with hot air at 130°C for 10 minutes. The colloidal silica active ingredient was deposited on the nonwoven fabric in an amount of 0.1% by weight of the fibers. This nonwoven fabric was impregnated with the water-containing slurry obtained in Example 1 and left for 25 minutes in an atmosphere at a temperature of 60° C. and a relative humidity of 60%, and then dried in a hot air dryer at 130° C. for 10 minutes. The obtained sheet-like material was hard and weak, and the effects of the present invention were not affected. This characteristic is shown in Table-1.

Comparative Example 2 The colloidal silica-untreated nonwoven fabric used in Example 1 was impregnated with the water-containing slurry obtained in Example 1, and then the temperature was 6.
After being left in an atmosphere of 0°C and 60% relative humidity for 25 minutes, it was dried in a hot air dryer at 130°C for 10 minutes. The obtained sheet-like material was hard and weak. This characteristic is shown in Table-1.

Comparative Example 3 Hydrous silicone was added to the fiber weight (0.5% treated) to the nonwoven fabric used in Example 1.
This nonwoven fabric was impregnated with the water-containing slurry obtained in Example 1.
After being left for 5 minutes, it was dried with hot air at 130°C for 10 minutes. Although the obtained sheet-like material had good flexibility, it was weak and unreliable. This characteristic is shown in Table-1.

Example 4 (1) Preparation of surfactant Polypropylene glycol a, i with an average molecular weight of 2050
oo part and +1. To the terminal isocyanate product obtained by reacting 1-765 parts of I'l'-diphenylmethane diisocyanate, 3.100 parts of polyoxyethylene glycol having an average molecular weight of 1,540 was added to avoid the reaction, and an interface having urethane groups was formed. The activator is 17.

(2) Preparation of water-containing slurry 10 parts of the surfactant was added to 1,300 parts of the water-containing slurry obtained in Example 1 and mixed by stirring.

(3) Impregnation The obtained water-containing slurry was impregnated into the nonwoven fabric treated with colloidal silica of Example 1, and then left in an atmosphere of 0°C and 60% relative humidity for 25 minutes, and then heated to 130°C.
It was dried in a hot air dryer for 10 minutes.

The obtained sheet 1-like material had good flexibility and stiffness, and these properties are shown in Table 1. Example 5 10 parts of the urethane group-containing surfactant prepared in Example 3 were added to 1,280 parts of the water-containing slurry obtained in Example 2 and mixed with stirring. Obtained I: The water-containing slurry of Example 1 was impregnated into the -C-treated nonwoven fabric of rhoidal silica, and then left in an atmosphere at a temperature of 60°C and relative humidity of 60% for 25 minutes, and then at 130°C for 10 minutes. fever E
It was dried in an il dryer. The obtained sheet-like material has good flexibility and stiffness, and these properties are shown in the table below.
Shown in 1.

Example 6 The water-containing slurry prepared in Example 3 to which the urethane group-containing surfactant was added was added to the colloidal silica of Example 1 with -C
After impregnating the treated nonwoven fabric, it was immersed in a water bath for 3 minutes, and then soaked in an atmosphere at a temperature of 60°C and a relative humidity of 60% for 2 hours.
After being allowed to stand for 5 minutes, it was dried at 130°C for 10 minutes in an Atagawa drying oven. The obtained sheet-like material has good flexibility and stiffness, and these properties are shown in Table 1.

Example 7 The nonwoven fabric treated with colloidal silica of Example 1 was impregnated with the water-containing slurry prepared in Example 4 to which the urethane group-containing surfactant was added, and then immersed in a water bath for 3 minutes, followed by humidity control. 25 in an atmosphere of 60℃ and 60% relative humidity.
After being left for a minute, it was dried in a hot air dryer at 130°C for 10 minutes. The obtained sheet 1-like material had good flexibility and stiffness, and these properties are shown in Table 1.

(Leaving space below) Table 1: 11 tl of Boshi-like sea 1-shaped material Treatment L As detailed above, the method of the present invention provides better flexibility and better back strength than the conventional method. A stone-like leather-like sheet material can be provided. In other words, there is a material C'' that can increase the waist strength/flexibility (P5/RB) value, which is a measure of naturalness, and provides a leather-like sheet material with unprecedented natural leather-like characteristics. .

Claims (6)

[Claims] (1) Boiling point is 120℃ or less and 1 to 100g
A solution or slurry of polyurethane obtained by reacting a long-chain glycol with an average molecular weight of 500 to 5,000, a diisocyane-1 or more, and a low-molecular-weight diol in an organic solvent (a) that dissolves 50 g of water. A fibrous base fabric obtained by adding and mixing 10 to 95% by weight of water with zero addition of critical water to the solution or slurry to form a water-containing slurry, and treating the water-containing slurry with a treatment liquid containing colloidal silica as a main component. A method for producing a leather-like sheet material, which comprises impregnating and/or coating the water-containing slurry, selectively evaporating the organic solvent (a) from the water-containing slurry to gel it, and then drying it. (2) The water-containing slurry contains a hydrophobic component mainly consisting of a compound selected from the group consisting of polyalkylene oxides other than polyethylene oxide, aliphatic polyesters, and mixtures thereof, and a hydrophilic component mainly consisting of polyethylene oxide. , both components are substantially urethane bonded and/or
or a surfactant bonded only through amide bonds, wherein the hydrophilic component accounts for 30 to 30% of the entire surfactant.
Molecular weight accounting for 80% by weight: 2,500-30,000
0.2 parts of surfactant per 100 parts of the polyurethane
A method for producing a leather-like sheet 1 according to claim 1, wherein 10.0 parts to 10.0 parts are added and mixed. (3) After impregnating the fibrous base fabric with the water-containing slurry, 1
3. The method for producing a leather-like sheet 1 according to claim 2, which comprises soaking the slurry in water for at least a minute and then selectively evaporating the organic solvent (a) from the water-containing slurry to gel it. (4) Boiling point is 120℃ or less and 1 to 100g
In an organic solvent (a) that dissolves 50 g of water, a hydrophobic long-chain glycol with an average molecular weight of 500 to 5,000, a polyoxyethylene glycol with an average molecular weight of 500 to 5,000, an organic diisocyanate and a Polyurethane solution or slurry obtained by reaction with molecular diol,
10 to 95% by weight of water based on the added amount of critical water is added and mixed to the solution or slurry to form a water-containing slurry, and the water-containing slurry is treated with a treatment liquid containing rhoidal silica as a main component. A method for producing a leather-like sheet material, which comprises: impregnating and/or coating the water-containing slurry, selectively evaporating the organic solvent (a) from the water-containing slurry to form a gel, and then drying the slurry. (5) ○In the water slurry, a hydrophobic component mainly consisting of a compound selected from the group consisting of polyalkylene oxide other than polyethylene oxide, aliphatic polyester, and a mixture thereof, and a hydrophilic component mainly consisting of polyethylene oxide. Therefore, both components are substantially urethane-bonded rice/
or a surfactant bonded only through amide bonds, wherein the hydrophilic component accounts for 30 to 30% of the entire surfactant.
Molecules accounting for 80% by weight fi 2,500-30,00
0 of the surfactant per 100 parts of the polyurethane.
The method for producing a leather-like sheet material according to claim 4, wherein 2 to 10.0 parts are added and mixed. (6) After impregnating the fibrous base fabric with the water-containing slurry,
6. The method for producing a leather-like sheet material according to claim 5, which comprises soaking the slurry in water for 1 minute or more, and then selectively evaporating the organic solvent (a) from the water-containing slurry to gel it.