JPH062986B2 - Method for producing leather-like sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a leather-like sheet, and more specifically, a leather-like sheet having a silver surface with good pillow trace recovery and crease recovery. The present invention relates to a method of manufacturing a product.

(Prior Art) As a leather-like sheet material, a woven or non-woven fabric using fibers such as cotton, rayon, polyacid, polyester, polyacrylonitrile, or a base material obtained by filling a resin such as a polyurethane elastomer therewith. It is known that a solution of a polyurethane elastomer in a water-miscible organic solvent is applied, treated with a water-based coagulating liquid to be wet-coagulated, and further subjected to processing such as embossing and coloring finish.
Currently, it is widely used for shoes, balls, bags, clothing, interior materials, etc.

However, these conventional leather-like sheet-like materials having a wet silver surface layer have a drawback that the traces of the pressing metal fittings used during shoe molding (which are referred to as pillow traces) remain after the shoe sole is molded. At the time of transportation, such as when molded into balls, it is usually evacuated to reduce the bulkiness, and it is packed in a half-circle cap shape that is crushed in two. It has the drawback that folds and wrinkles sometimes remain.

In order to solve these drawbacks, nonionic surfactants have been added to the silver surface. However, in the case of this method, when the sheet-like material is stored, the In addition to the problem that the surface quality of the sheet-like material is significantly impaired by bleeding on the surface of the sheet or oligomers and additives in the silver surface that migrate and precipitate on the surface due to bleeding of the surfactant. In terms of pillow trace recovery and crease recovery, it is difficult to say that it is sufficient.

(Problems to be Solved by the Invention) In view of the problems of the prior art as described above, the inventors of the present invention are excellent in pillow trace recovery property and crease recovery property, and further, bleeding occurs even during long-term storage. As a result of intensive research on a method for producing a leather-like sheet material with a silver surface without quality deterioration, the present invention has been completed.

(Means for Solving Problems) That is, according to the present invention, a water-miscible organic solvent solution of a polyurethane elastomer is applied to at least one surface of a substrate and treated with an aqueous coagulating liquid to form a silver surface layer on the substrate. In the method for producing a leather-like sheet material consisting of the above, as the polyurethane elastomer solution, a nonionic surface-active compound is bound to both ends of a polyol of the same series as the polyol constituting the polyurethane elastomer via an organic diisocyanate. A sparingly water-soluble or water-insoluble modified surfactant is added to the polyurethane elastomer solid content.
The method for producing a leather-like sheet material is characterized by using an additive in the range of 1 to 20% by weight.

The leather-like sheet material with a silver surface obtained by the method of the present invention has excellent pillow mark recovery properties, crease recovery properties, storage stability (bleeding resistance), and good texture. With such a sheet-like material, it is possible to provide shoes, balls, bags, etc. with excellent appearance and performance.

In the present invention, the modified surfactant added to the solution of the polyurethane elastomer (which may hereinafter be referred to as a silver surface polyurethane elastomer) that constitutes the silver surface is the same type as the polyol of the silver surface polyurethane elastomer. The compound represented by the following formula, in which a nonionic surface-active compound is bound to both ends of the polyol by an organic diisocyanate, and is poorly soluble or insoluble in water.

In the above formula, ○ is an organic diisocyanate residue Means

As the nonionic surface active compound, polyethylene glycol alkylphenyl monoether, polyethylene glycol alkyl monoether, polyethylene glycol fatty acid monoester, N-polyethylene glycol alkylamine, sorbitan fatty acid monoester, polyethylene glycol sorbitan fatty acid monoester. Among polypropylene glycol polyethylene glycol block copolymer ethers, those having a hydrophilic group-hydrophobic group balance (Hydrophile-Lipophile Balnce abbreviation HLB) of 14 or less are preferably used.

Among them, the molecular weight is 1,000 to 20,000, and the content (weight fraction) of ethylene oxide chains in all molecules is 10
Polypropylene glycol polyethylene glycol block copolymer ethers of up to 70% are preferred.

It is an essential condition that the polyol is of the same type as that of the polyol constituting the silver-faced polyurethane elastomer.

The same system here means that when the polyol constituting the silver-faced polyurethane elastomer is a polyester-based polyol, the polyol of the modified surfactant also uses a polyester-based polyol, and the polyol constituting the silver-faced polyurethane elastomer is poly If it is an ether type polyol, it means that the polyol of the modified surfactant also uses a polyether type polyol.

When the polyols are not of the same series, for example, when a modified surface-active agent containing polyether polyol is contained in a silver surface polyurethane elastomer composed of polyester polyol, pillow trace recovery and crease recovery are obtained. A leather-like sheet with poor properties cannot be obtained, and the bleeding resistance is also poor.

The modified surfactant polyol may be of the same type as that of the silver-faced polyurethane elastomer in the above sense, and other molecular weights, compositions (repeating units), etc. are not necessarily the same, but the molecular weight, composition, etc. The same is more preferable.

Specific polyols include polyester-based polyols such as polyethylene adipate glycol, polypropylene adipate glycol, polyethylene propylene adipate glycol, polybutylene adipate glycol, polyethylene butylene adipate glycol, polypentamethylene adipate glycol, or polyethylene ether glycol, polypropylene ether. Polyether polyols such as glycol, polytetramethylene ether glycol and polyhexamethylene ether glycol, and further polycaprolactones obtained by ring-opening polymerization of lactone ring, etc. having a hydroxyl group at both ends 5
Examples include glycols of 00 to 8000 and the like.

Examples of organic diisocyanates include diphenylmethane-4,4'-diisocyanate and tolylene-
2,4-diisocyanate, xylylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, hexamethylene diisocyanate and the like can be used.

Synthesis of the modified surfactant having the above-mentioned constitution is carried out, for example,
Under normal pressure, in a nitrogen atmosphere, in an organic diisocyanate in a state of being melted or dissolved in an organic solvent such as dimethylformamide, while continuing stirring, a polyol equivalent to 1/2 mol of the organic diisocyanate is added, and the temperature is raised. 50 ~
100 to 60 ° C, preferably 60 to 180 at a temperature of 60 to 80 ° C
It is carried out by adding a nonionic surface-active compound to the intermediate product obtained by reacting for minutes and further continuing the reaction at 50 to 100 ° C., preferably 60 to 80 ° C. for 60 to 180 minutes. The nonionic surface-active compound used here is added in an amount corresponding to zero reactive isocyanate groups in the final product.

The modified surfactant used in the present invention has the above-mentioned constitution and is sparingly water-soluble or water-insoluble. Here, the term “poorly water-soluble or water-insoluble” generally means that the solubility in 100 g of water (25 ° C.) is about 1 g or less, although it is slightly different depending on the molecular weight and composition of the modified surfactant.

If the modified surfactant is easily soluble in water, most of it is eluted during the wet coagulation process of the polyurethane elastomer solution or the subsequent water washing process, and the effect of improving pillow trace recovery and crease recovery is obtained. I can't.

Examples of the substrate used in the present invention include knitted and woven fabrics made of natural fibers, recycled fibers, or synthetic fibers, and styrene-butadiene copolymer, nitrile-butadiene copolymer, polyurethane, polyvinyl acetate, etc. And the base material obtained by impregnating and solidifying the synthetic elastomer or synthetic resin.

Examples of the silver surface polyurethane elastomer used in the present invention include the same polyols and organic diisocyanates as described in the section of the modified surfactant, and ethylene glycol, propylene glycol, butylene glycol, pentamethylene glycol, diethylene glycol, tetraethylene glycol and the like. There are polyurethane elastomers obtained by polymerizing low molecular chain extenders such as glycols, hydrazine, diamines such as 1,2-propylenediamine and hexamethylenediamine.

In the present invention, a modified surfactant is added to a water-miscible organic solvent solution of the above-mentioned silver-faced polyurethane elastomer, such as a dimethylformamide solution, a dimethylacetamide solution, or a dimethylsulfoxide solution, and this is applied to a substrate. In this case, a colorant such as a pigment or a dye, or an antiaging agent may be added to the organic solvent solution, if necessary. The amount of the modified surfactant added to the silver surface polyurethane elastomer solution is in the range of 0.1 to 20% by weight, and preferably in the range of 1 to 15% by weight, based on the solid content of the polyurethane elastomer.

When the amount of the modified surfactant added is less than 0.1% by weight, the effect of improving pillow trace recovery and crease recovery is not sufficient, while when the amount added exceeds 20% by weight, the silver surface polyurethane elastomer is coagulated and regenerated. However, the smoothness of the silver surface and the surface quality of the obtained sheet-like product are significantly impaired.

The step of applying the above-mentioned polyurethane elastomer solution containing the modified surfactant to the substrate and treating with a water-based coagulating liquid to obtain a leather-like sheet having a silver surface can be carried out by a conventional method.

That is, a modified surfactant and, if necessary, a coloring agent, an antioxidant, etc. are added, and the elastomer solid content is adjusted to 10%.
To 40% by weight, preferably 10 to 35% by weight, of a water-miscible organic solvent solution of polyurethane elastomer,
Using a suitable coating means such as a roll coater or a knife coater, it is generally 150 to 1000 g / m ² , preferably 300 to 800, on at least one surface of the substrate as described above.
Apply so that the applied amount (as a solution) is g / m ² ,
Then, a leather-like sheet having a porous silver surface is obtained by immersing in water or a mixture of water and a solvent of polyurethane elastomer and wet-coagulating it, washing with water (desolvation), and drying. .

The modified surfactant used in the present invention has a polyol of the same series as the polyol constituting the silver-faced polyurethane elastomer in its molecule, and therefore has extremely excellent compatibility with the polyurethane elastomer and also has a modified surfactant. The urethane bond in the molecule of the agent has the property of easily forming an intermolecular bond with the urethane bond of the polyurethane elastomer.

Therefore, the modified surfactant of the present invention has a great affinity for the silver surface polyurethane elastomer and is difficult to separate from the polyurethane elastomer even after a long time, and the modified surfactant itself is formed on the surface of the leather-like sheet material. Bleed,
Alternatively, it is very unlikely that the product is contaminated by promoting bleeding to the surface of low molecular weight oligomers and the like which are latent in the silver surface layer of the leather-like sheet. Further, the modified surfactant of the present invention has a hydrophilic / hydrophobic nonionic surfactant compound at its molecular end, and by the action of the hydrophilic / hydrophobic nonionic surfactant compound as a surfactant. The leather-like sheet obtained has very good pillow trace recovery and wrinkle recovery.

The leather-like sheet material obtained by the method of the present invention is used as it is or after further forming an embossing or colored finishing layer on the surface thereof and used as shoes, balls, bags, cases, clothing, interior materials and the like. Hereinafter, the method of the present invention will be described in more detail with reference to Examples.

All parts and% in this example relate to weight unless otherwise specified, and the solubility is a value measured at 25 ° C. Further, the methods for measuring the pillow trace recovery property, the crease recovery property, the bleeding resistance property, and the surface smoothness described in the examples are as follows.

(1) Pillow mark recovery property Prepare a test sample with a size of 4 cm x 6 cm. Place this sample with the silver layer facing up on the pressing surface of a flat press machine,
On top of that, put 1 mm thick 4 cm x 6 cm pig's natural leather, and attach the convex metal fittings to the convex part (top surface: about 6 cm in area).
Place the oval horizontal plane ² ) face down.

This is pressed at room temperature under a pressing pressure of 30 kg / cm ² for 15 seconds, and then the pressure is released to measure the time for recovery of the pillow mark of the sample (silver surface).

(2) Wrinkle recovery property Prepare a test sample with a size of 4 cm x 6 cm. This sample was folded in two at the center and placed on the pressing surface of the press with the silver surface layer facing inward, and the pressing pressure was 15 at room temperature.
Press for 5 seconds under the condition of kg / cm ² , then release the pressure and measure the time for recovery of the creases of the sample (silver surface).

(3) Bleed resistance A black surface finish paint was sprayed to the thickness of 20μ on the silver side of the sheet material, dried at 120 ° C for 10 minutes, and used as a bleed judgment sample. It was carried out and the quality of bleeding resistance was judged.

Dry heat bleeding resistance A sample of 20 cm x 20 cm was applied to the half surface (10 cm x 2
0 cm) is covered with a polyester film having a thickness of 40 μ and wound on a paper tube having a diameter of 2 cm with the surface inside, and this is left for 30 days in a temperature and humidity controller at a temperature of 50 ° C. and a humidity of 30% RH. The sample was taken out, and the surface of the sample wound in contact with the polyester film surface and the back surface of the sample was observed with the naked eye, and the bleed resistance was judged according to the following five-stage evaluation based on the presence or absence and the degree of bleed.

5th grade: No bleeding at all 4th grade: Very slight bleeding 3rd grade: slightly bleeding 2nd grade: equivalent bleeding 1st grade: extremely remarkably Produces bleed Wet heat bleed resistance Prepare a sample in the same manner as for dry heat bleed resistance and set the temperature to 5
After being left in a temperature and humidity controller at 0 ° C. and 95% RH for 30 days, it was taken out and the bleed resistance was evaluated according to the same criteria as the dry heat bleed resistance.

(4) Surface smoothness The polyurethane elastomer solution is applied on a glass plate having a size of 15 cm × 10 cm by 800 g / m ² at 35 ° C.
Was immersed in the coagulation bath (water: dimethylformamide = 70: 30 (weight ratio)) for 10 minutes for coagulation. Then
After removing the solvent by immersing it in warm water of 60 ° C. for 1 hour,
Hot air drying was performed at 120 ° C. The surface of the porous polyurethane film thus obtained was visually observed, and the smoothness of the surface was evaluated according to the following five-grade evaluation.

Grade 5: Very smooth surface 4th grade: slight surface irregularities 3rd grade: slight surface irregularities 2nd grade: equivalent surface irregularities 1st grade ... extremely remarkably unevenness of the surface is produced Example 1 (1) Preparation of modified surfactant 50 parts of diphenylmethane-4,4'- in a molten state
150 parts of polyethylene butylene (4: 6 mol) adipate glycol (polyol) having a molecular weight of 1500 was added to diisocyanate, and this mixture was reacted at 80 ° C. for 60 minutes. 700 parts of polypropylene glycol polyethylene glycol block copolymer ether [nonionic surface-active compound, molecular weight 333] was added to the obtained intermediate product.
3, propylene oxide chain / ethylene oxide chain =
60/40 (weight ratio), HLB8], and at
The reaction was performed for 0 minutes to obtain a modified surfactant. The solubility of this modified surfactant in water was 0.5 g / 100 g (hereinafter this is simply referred to as 0.5 g).

(2) Manufacture of leather-like sheet with fineness of 1.5 denier, crimp number of 15 threads / inch, fiber length of 51 m
Using a 6-nylon staple of m, create a web with a card and a cross wrapper, and pass the web through a double needle rocker room, and 1000 sheets / cm from the top and bottom.
² needle punching, weight 200g / m ² ,
A three-dimensional nonwoven fabric with a thickness of 1.0 mm and an apparent density of 0.20 g / cm ³ was used.

Next, this non-woven fabric was treated with a polyurethane elastomer dimethylformamide solution having a solid content of 18% (polyethylene butylene (1: 1 mol) having a molecular weight of 1500) adipate glycol, diphenylmethane-4,4'-diisocyanate and ethylene glycol as a chain extender in dimethylformamide. (Prepared by reacting at a molar ratio of 1: 5: 4) to impregnate the solution with 400% amount,
Coagulation bath at 40 ° C. [water: dimethylformamide = 80: 2
0 (weight ratio)] to solidify. Then 50 ℃
After washing in warm water for 1 hour, hot air drying was performed at 120 ° C. to obtain a substrate.

Separately, polybutylene adipate glycol (polyester polyol) having a molecular weight of 1500, diphenylmethane-4,4'-diisocyanate and butylene glycol as a chain extender in dimethylformamide in a molar ratio of 1:
The reaction was carried out at 60 ° C. for 8 hours at 4: 3 to obtain a 28% dimethylformamide solution of polyurethane elastomer.

To this polyurethane elastomer solution, the modified surfactant prepared above was added to the polyurethane elastomer solids at 0,0.05,0.1,0.5,1,2,5,10,15,2.
After adding and dissolving 0.25%, each of the resulting modified surfactant-containing polyurethane elastomer solutions was applied to the above-mentioned substrate at 800 g / m ² and then coagulated at 35 ° C. [water: dimethylformamide]. = 70: 30 (weight ratio)]. Then, after immersing in warm water of 60 ° C. for 1 hour to remove the solvent, hot air drying was performed at 120 ° C.

The leather-like sheet thus obtained weighs about 565 g.
/ M ² , thickness about 1.35 mm, apparent density 0.39 g / cm ³ ,
The characteristics are shown in Table 1. It can be seen from Table 1 that the sheet-like products (Invention 1 to 9) produced by the method of the present invention have excellent pillow mark recovery, crease recovery and bleeding resistance. On the other hand, when the modified surfactant is not added or a polyurethane elastomer solution having a ratio of less than 0.1% is applied (Comparative Examples 1 and 2), it is inferior in pillow trace recoverability and crease recoverability, and When the ratio of the modified surfactant exceeded 20% (Comparative Example 3), the smoothness of the surface was significantly impaired, and any of them was unsuitable.

Comparative Examples 4 to 7 Instead of the modified surfactant of Example 1, the following surfactants were added to the polyurethane elastomer solution (however,
The compounding amount is 5 with respect to the polyurethane elastomer solid content.
%), And skin-like sheets were obtained in the same manner as in Example 1.

Subcutaneous Example 4: Polypropylene glycol polyethylene glycol block copolymer ether (nonionic surfactant compound, same as in Example 1). The solubility of this product in water was 30 g.

Comparative Example 5: 50 parts of diphenylmethane-4,4'-diisocyanate was mixed with 1333 parts of polypropylene glycol polyethylene glycol block copolymer ether (nonionic surface-active compound, the same as in Example 1), and the mixture was heated at 80 ° C.
Modified surfactant obtained by reacting for 90 minutes. The solubility of this product in water was 6 g.

Comparative Example 6: 50 parts of diphenylmethane in the molten state
A mixture of 4,4'-diisocyanate and 333 parts of polypropylene glycol polyethylene glycol block copolymer ether (nonionic surfactant, same as in Example 1) was reacted at 80 ° C for 60 minutes, and then polyethylene buoy was added thereto. Len (4: 6 mol) adipate glycol (polyol, same as Example 1) 315
Parts, and a modified surfactant obtained by reacting at 80 ° C. for 90 minutes. The solubility of this product in water was 0.5 g.

Comparative Example 7: 50 parts of diphenylmethane in a molten state
A mixture of 4,4'-diisocyanate and 150 parts of polytetramethylene ether glycol (polyether polyol) having a molecular weight of 1500 was reacted at 80 ° C for 60 minutes, and then 700 parts of polypropylene glycol polyethylene glycol block copolymer was added thereto. A modified surfactant obtained by adding ether (nonionic surfactant, the same as in Example 1) and reacting at 80 ° C. for 90 minutes. The solubility of this product in water was 0.6 g.

For the leather-like sheet obtained in each of the above comparative examples,
Table 2 shows the results of measurement of pillow trace recovery, crease recovery, bleeding resistance, and surface smoothness.

In Table 2, the results of Inventive Example 5 of Example 1 (the compounded amount of the modified surfactant is 5%) are shown again for comparison.

As is clear from the results in Table 2, when the composition of the modified surfactant to be used does not satisfy the requirements of the present invention, the obtained leather-like sheet materials are all pillow trace recoverability, crease recoverability, It is insufficient in terms of bleed resistance and surface smoothness.

Comparative Examples 8 and 9 Instead of the modified surfactant of Example 1, the following nonionic surfactants are blended in the polyurethane elastomer solution (however, the blending amount is 5% based on the solid content of the polyurethane elastomer). Otherwise in the same manner as in Example 1, leather-like sheet materials were obtained.

Comparative Example 8: A surfactant in which three polypropylene glycols having a molecular weight of 2000 to 3000 are bonded to the OH groups of the 1,2,3 position carbons of glycerin. The solubility of this product in water was 0.1 g or less.

Comparative Example 9: Sorbitan monooleate. The solubility of this product in water was 0.5 g.

For the leather-like sheet obtained in each of the above comparative examples,
Table 3 shows the results of measurement of pillow trace recovery, crease recovery, bleed resistance, and surface smoothness.

In addition, in Table 3, the results of Example 5 of the present invention of Example 1 (the compounding amount of the modified surfactant is 5%) are repeated for comparison.

As is clear from the results in Table 3, a leather-like sheet obtained by applying a normal nonionic surfactant in a polyurethane elastomer solution to a base material and wet-coagulating it has a pillow trace recoverability. Not only is it difficult to recover creases, but it is particularly poor in bleeding resistance and poor in practicality.

Example 2 (1) Preparation of Modified Surfactant To 50 parts of melted diphenylmethane-4,4'-diisocyanate, polyethylene adipate glycol (polyester polyol) having a molecular weight of 1500 was added in an amount of 15 parts.
0 part was added, and the mixture was reacted at 80 ° C. for 60 minutes. To the obtained intermediate product, 700 parts of polypropylene glycol polyethylene glycol block copolymer ether (the same as in Example 1) was added as a nonionic surfactant compound, and the mixture was reacted at 80 ° C. for 90 minutes to obtain a modified surfactant. It was The solubility of this modified surfactant in water is 0.
It was 7 g.

(2) Manufacture of leather-like sheet material The modified surfactant was added to the same 28% polyurethane elastomer solution as in Example 1 in an amount of 5% based on the solid content of polyurethane elastomer, and the solution was used as a coating solution. A leather-like sheet material was produced in the same manner as in Example 1.

The leather-like sheet obtained here has a pillow trace recoverability of 2 minutes,
Bending wrinkle recovery was 4 minutes, dry heat bleed resistance grade 5, wet heat bleed resistance grade 5, and surface smoothness grade 5 were all good results.

Example 3 (1) Preparation of modified surfactant 50 parts of diphenylmethane-4,4'- in a molten state
To the diisocyanate, 150 polytetramethylene glycol (polyether polyol) with a molecular weight of 1500
Part of the mixture, and the mixture was allowed to react at 80 ° C. for 60 minutes to give an intermediate product. 700 parts of polyethylene glycol polypropylene glycol block copolymer ether [molecular weight 3333, propylene oxide chain / ethylene oxide chain = 60/40, HLB8], 80 ℃
At 90 ° C. for 90 minutes to obtain a modified surfactant. The solubility of this modified surfactant in water was 0.5 g.

(2) Manufacture of leather-like sheet polytetramethylene glycol (polyether polyol) having a molecular weight of 1500, diphenylmethane-4,4 '
Diisocyanate and butylene glycol as chain extender in dimethylformamide in a molar ratio of 1: 4: 3 60
28 hours of polyurethane elastomer
% Dimethylformamide solution was obtained.

The modified surfactant prepared above was added to the polyurethane elastomer solution in an amount of 10% based on the solid content of the polyurethane elastomer, and dissolved. The modified surfactant-containing polyurethane elastomer solution obtained here was used in Example 1. A leather-like sheet material was produced in the same manner as in Example 1 except that 800 g / m ^{2 was} applied to the same base material as in (1) above.

The leather-like sheet obtained here has a pillow trace recoverability of 1 minute,
Bending wrinkle recovery was 2 minutes, dry heat bleed resistance grade 5, wet heat bleed resistance grade 5, and surface smoothness grade 5 were all good results.

Example 4 (1) Preparation of modified surfactant 50 parts of diphenylmethane-4,4'- in a molten state
150 parts of polyethylene adipate glycol (polyol) having a molecular weight of 1500 is added to diisocyanate,
This mixture was reacted at 80 ° C. for 60 minutes. In the obtained intermediate product, a propylene oxide chain / ethylene oxide chain ratio (weight ratio) as a nonionic surface-active compound
Is 80/20, 60/40, 40/60, 30/70,
And 5760 polypropylene glycol polyethylene glycol block copolymer ether (molecular weight 8000), which is 20/80, or 1760 parts of polyethylene glycol (molecular weight 8000), respectively,
Six types of modified surfactants were obtained by reacting at 80 ° C. for 90 minutes.

(2) Production of leather-like sheet material A coating solution was prepared by dissolving each of the above 6 types of modified surfactants in the same 28% polyurethane elastomer solution as in Example 1 in an amount of 5% based on the solid content of the elastomer. A leather-like sheet was manufactured in the same manner as in Example 1.

The characteristics of the obtained 6 kinds of leather-like sheet materials are shown in Table 4.

Note: (1) Propylene oxide chain / ethylene oxide chain ratio (weight ratio) (2) Polyethylene glycol From the results of Table 4, in the case of the modified surfactant of this example,
When the solubility in water exceeds 1 g and the solubility becomes 7 g or 18 g, the obtained leather-like sheet material (Comparative Examples 10, 1
It is clear that 1) results in insufficient pillow trace recovery and crease recovery.

Example 5 (1) Preparation of modified surfactant 50 parts of diphenylmethane-4,4'- in a molten state
To diisocyanate, 150 parts of polyethylene adipate glycol having a molecular weight of 1500 was added, and this mixture was added to 8 parts.
The intermediate product obtained by the reaction at 0 ° C. for 60 minutes contained either 83 parts of polyethylene glycol nonylphenyl ether (ethylene oxide 4 mol adduct, HLB9) and 85.6 parts of sorbitan monooleate (HLB4.3). Seeds were added and reacted at 80 ° C. for 90 minutes to obtain two types of modified surfactants.

(2) Manufacture of leather-like sheet material A coating solution was prepared by adding each of the above two types of modified surfactants to the same 28% polyurethane elastomer solution as in Example 1 in an amount of 5% based on the solid content of the polyurethane elastomer. A leather-like sheet was manufactured in the same manner as in Example 1.

The properties of the obtained leather-like sheet are shown in Table 5.

Example 6 (1) Preparation of modified surfactant 50 parts of diphenylmethane-4,4'- in a molten state
150 parts of polyethylene butylene (1: 1 mol) adipate glycol having a molecular weight of 1500 was added to diisocyanate, and the mixture was reacted at 80 ° C. for 60 minutes to obtain an intermediate product, and 200 parts of polyethylene glycol sorbitan monostearate was added. (Molecular weight 958, ethylene oxide 12 mol adduct, HLB12) was added, and
The modified surfactant was obtained by reacting at 90 ° C. for 90 minutes. The solubility of this product in water was 0.3 g.

(2) Manufacture of leather-like sheet with a fineness of 1.5 denier, fiber length of 35 mm, shrinkage of 5 in boiling water
A 0% high-shrinkage polyethylene terephthalate staple was used to prepare a web with a card and a cross-wrapper, the web was introduced into a tabular needle rocker room, and 1000 needles / cm ² were needle punched from above and below to obtain a three-dimensional nonwoven fabric. . Then, the non-woven fabric was heat-treated in hot water at 80 ° C. and dried with a cylinder dryer to obtain a shrinkable non-woven fabric having a thickness of 1.2 m / m and an apparent density of 0.22 g / cm ³ , and a styrene-butadiene having a solid content of 18%. Immerse in rubber latex to impregnate 400% of the latex, then dry and solidify, then wash in warm water at 50 ° C. for 1 hour,
Hot air drying was performed at 120 ° C.

The base material obtained here has a weight of 455 g / m ² and a thickness of 1,3 m /
m, apparent density was 0.40 g / cm ³ .

Next, a solution prepared by adding the above modified surfactant and carbon black to the above-mentioned base material in the same 28% polyurethane elastomer solution as in Example 1 in amounts of 5% and 3.5% based on the polyurethane elastomer solid content, respectively. After coating with a knife coater at an amount of 700 g / m ² , 30 in a 30 ° C aqueous solution (coagulation bath) containing 20% of dimethylformamide.
Soak for 1 minute to completely solidify, wash with hot water at 60 ° C for 90 minutes to remove the solvent, dry with hot air at 120 ° C and weigh 6
A leather-like sheet having a thickness of 51 g / m ² and a thickness of 1.6 mm was obtained.

The obtained leather-like sheet had a pillow trace recovery property of 1 minute and a crease recovery property of 2 minutes. The bleeding property was excellent in both dry heat and wet heat of grade 5, and the surface smoothness was also good. .

By embossing and surface-finishing this leather-like sheet material, it became a material suitable for use in shoes, balls, cases and the like.

Example 7 Mixed spun yarn 20 of polyester / rayon = 65/35
A raised fabric obtained by raising one side of a twill fabric (weft 72 yarns / inch × warp 65 yarns / inch) in which a twin yarn of count is a weft and a single yarn of the same mixed spun yarn is a warp A 28% polyurethane elastomer solution similar to that used in Example 1 was diluted with dimethylformamide to a concentration of 20% on the napped surface of Example 1 to obtain a modified surfactant similar to that used in Example 1 in an amount of 5% based on the solid content of polyurethane elastomer. Only 800 g / m ^{2 of the} added material was applied, and a leather-like sheet material was obtained in the same manner as in Example 1 below.

The obtained leather-like sheet had a pillow trace recovery property of 2 minutes, a crease recovery property of 4 minutes, and bleeding properties of dry heat and wet heat of grade 5, and the surface smoothness was excellent.

By further embossing and surface-finishing this leather-like sheet material, it became a material suitable for use in shoes, cases and the like.

〔The invention's effect〕

According to the method of the present invention in which the polyurethane lastomer solution containing the specific modified surfactant is used as a coating solution, a leather-like sheet having good bleeding resistance and excellent recovery from pillow marks and creases is obtained. It is possible to manufacture, and thus, a leather-like sheet material having a suitable favorable texture and high performance and characteristics is provided here.

Claims (1)

[Claims] 1. A method for producing a leather-like sheet material, which comprises coating a water-miscible organic solvent solution of a polyurethane elastomer on at least one surface of a substrate and treating it with an aqueous coagulating liquid to form a silver surface layer on the substrate. In the above-mentioned polyurethane elastomer solution, a sparingly water-soluble or water-insoluble modified surfactant in which a nonionic surface-active compound is bonded to both ends of a polyol constituting the polyurethane elastomer by way of an organic diisocyanate 0.1 to 0.1% with respect to the polyurethane elastomer solid content.
A method for producing a leather-like sheet material, characterized in that it is used in the range of 20% by weight.