JP3121460B2 - Leather-like sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leather-like sheet having a slimy surface and good feeling. More specifically, having a surface slimy touch obtained by using a composition in which a polyurethane resin having a specific structure and a specific polyethylene glycol are blended in a specific ratio,
It relates to a leather-like sheet having a good feeling. The leather-like sheet material of the present invention has a unique slimy feeling without stickiness and is excellent in texture, so that it is useful as a material for clothing, interiors, bags, bags, shoes, and the like.

[0002]

2. Description of the Related Art Leather-like sheet materials made of polyurethane as a skin material are widely used as materials for seats for shoes, clothing, furniture, and vehicles such as automobiles. Demands for quality such as heat resistance and heat resistance are becoming more and more advanced. Many attempts have been made to satisfy these required performances by improving the properties of polyurethane resins. As one of the means, for example,
The type of polyurethane and its component composition are being changed.

JP-A-2-26486 discloses a polyester diol having a specific composition and a number average molecular weight of 300 to 5,
A sheet material obtained by impregnating and / or applying a solution obtained by mixing a coagulation modifier of a specific structure to a polyurethane elastomer containing 000 polyoxyalkylene glycol as a diol component, and coagulating with a non-solvent of the polyurethane Is shown. The publication discloses that polyethylene glycol is contained as a polyoxyalkylene glycol. It is disclosed that the obtained sheet-like material has good smoothness, flexibility, and excellent drape.

[0004] However, according to the method disclosed in this publication, not only a sheet-like material having good sliminess cannot be obtained, but also a polyurethane having a specific structure required by the present invention and a polyethylene glycol having an average molecular weight of 5,000 or more are used. It cannot be inferred by analogy that a leather-like sheet having a unique slimy touch can be obtained by blending in a specific ratio. Japanese Patent Application Laid-Open No. 29439/1990 proposes to use polyoxyethylene alkyl ether or the like in combination as a part of a coagulation regulator for wet coagulation of polyurethane. Is a comparatively low molecular weight, and even if the wet sponge forming property of polyurethane is improved, not only a sheet-like material having good sliminess is not obtained, but also a polyurethane having a specific structure which is a requirement of the present invention. It cannot be inferred by analogy that a leather-like sheet having a unique slimy touch can be obtained by blending the polyethylene glycol having an average molecular weight of 5000 or more with a specific ratio.

[0005]

In recent years, there has been a remarkable trend in the trend toward higher-grade consumerism and the emphasis on sensitivity and fashion. Leather-like sheet materials used as synthetic leather and artificial leather have been strongly demanded for texture, drapability, excellent touch feeling, and the like. Naturally, it must also have physical properties and durability.

The present inventors have found that by using a polyurethane obtained by polymerizing a specific polymer diol and polyethylene glycol having an average molecular weight of 5,000 or more as a polymer diol component, it is excellent in flexibility and drapability and drier. A leather-like sheet having such a slimy touch was proposed in Japanese Patent Application No. 4-254646. However, although the preferred performance can be obtained by this method, the number of types of raw material polyurethane increases in industrial production, which is not always preferable in terms of process management. An object of the present invention is to industrially stably provide a leather-like sheet having excellent flexibility and drapability and having a smooth slimy touch.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and have found that the average molecular weight is 500
When 0 or more polyethylene glycol is used, it is possible to achieve the object of the present invention without causing a problem such as bleed-out simply by mixing with polyurethane without copolymerization as a polymer diol component of polyurethane. We have found and completed the present invention.

[0008] That is, according to the present invention, the above objects are as follows: The number average molecular weight selected from the group consisting of polyester, polycarbonate and polylactone is 500 to 3000
A polyurethane obtained by reacting the polymer diol with an organic diisocyanate and a low molecular chain extender; B. 5 to 20 parts by weight of polyethylene glycol having an average molecular weight of 5,000 or more (based on 100 parts by weight of A); This is achieved by impregnating or / and applying an organic solvent solution comprising a water-miscible organic solvent onto a fiber base material and coagulating the fiber base with a non-solvent of the polyurethane of the component A.

First, the polymer diol which is a raw material of the polyurethane of the component A used in the present invention will be described.
Polymer diols are polyester, polycarbonate,
Selected from the group consisting of polylactones. Polyether diol is an essential component of the present invention and has a number average molecular weight of 5,000.
It is a compound similar to the above polyethylene glycol (B), and is not suitable for the purpose of the present invention because it has an affinity and cannot obtain a proper phase separation state which is considered to be an action mechanism of the present invention. The number average molecular weight of the polymer diol is 500 to 30
00 is desirable, more preferably 700
A range of ２2500 is selected. If it is less than 500, the leather-like sheet tends to lose its flexibility or its hand is lowered, which is not preferable. If it exceeds 3000, it may be difficult to obtain a leather-like sheet having a good balance of feeling, flexibility, cold resistance, heat resistance and durability, probably because the urethane group concentration is inevitably reduced. The polymer
There are difficulties in industrial production of diols, which is not preferred.

As the polymer diol, polyester, polycarbonate, and polylactone can be used alone or in a mixture at an arbitrary ratio.

The polyester diol used in the present invention can be obtained, for example, by reacting a dibasic acid with a diol. Examples of the dibasic acid include aromatic dibasic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, and brassic acid; One of the basic acids or a combination thereof can be used. Among these, aliphatic dibasic acids, especially dibasic acids having a methylene chain length of 4 to 8, such as adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, etc., are more preferably used. As the diol, ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, which may be substituted with a lower alcohol,
One or a mixture of two or more of aliphatic diols such as decane diol and dodecane diol, alicyclic diols such as cyclohexane diol, hydrogenated xylylene glycol, and aromatic diols such as xylylene glycol are used. Among them, aliphatic diols are one or a mixture of two or more aliphatic diols having a carbon chain length of 4 to 9, such as butanediol, methylpentanediol, hexanediol, heptanediol, methyloctanediol, and nonanediol. It is preferably used.

The polycarbonate diol can be obtained, for example, by reacting a carbonate compound with a diol. As the carbonate compound, dimethyl carbonate, diphenyl carbonate, ethylene carbonate and the like can be used. As the diol, ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, which may be substituted with a lower alcohol,
One or two or more aliphatic diols such as heptanediol, octanediol, nonanediol, decanediol and dodecanediol; alicyclic diols such as cyclohexanediol and hydrogenated xylylene glycol; and aromatic diols such as xylylene glycol. Mixtures of more than one species are used, of which aliphatic diols are
In particular, one or a mixture of two or more aliphatic diols having a carbon chain length of 4 to 9, such as butanediol, methylpentanediol, hexanediol, heptanediol, methyloctanediol, and nonanediol, are preferably used.

Examples of polylactone diols include poly-ε-caprolactone diol, poly-trimethyl-ε
-Caprolactonediol, poly-β-methyl-δ-valerolactonediol and the like.

Examples of the organic diisocyanate used in the present invention include 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate, meta- or para-phenylene diisocyanate, and 1,5-naphthylene diisocyanate. Aromatic diisocyanate, isophorone diisocyanate,
Cyclohexane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, 4,4 '
Non-aromatic diisocyanates such as dicyclohexylmethane diisocyanate; Among them, the organic diisocyanate to be reacted with the polymer diol and the chain extender is 4,4'-diphenylmethane diisocyanate, because the sheet-like material obtained by coagulation with a non-solvent has good surface sliminess and feeling. preferable.

Examples of the low molecular chain extender used in the present invention include ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol and octanediol which may be substituted with a lower alcohol. And aliphatic diols such as nonanediol, decanediol and dodecanediol; alicyclic diols such as cyclohexanediol and hydrogenated xylylene glycol; aromatic diols such as xylylene glycol; and diethylene glycol. These can be used as one kind or as a mixture of two or more kinds. Examples of more preferred low molecular chain extenders include aliphatic diols, especially ethylene glycol and butanediol, and are suitable in terms of balance of hand, flexibility, cold resistance, heat resistance and the like of a leather-like sheet. Used for

The amount of the low molecular chain extender to be used is not particularly limited, but it varies depending on its molecular structure, the molecular weight of the polymer diol, the type of organic diisocyanate, and the NCO / OH equivalent ratio. The equivalent ratio of [low molecular chain extender] / [polymer diol] is 0.5 to
Of these, leather-like sheet materials obtained from 1 to 5.5 are often suitable in terms of feeling, flexibility, cold resistance and heat resistance.

Regarding the solution viscosity of the polyurethane used in the present invention, the texture, drape property,
In order to improve the sliminess and the like, the solution viscosity at a solid concentration of 25% by weight in dimethylformamide solvent measured at 30 ° C. is preferably 5 to 2000 poise, and particularly preferably 50 to 1500 poise.

With respect to a specific operation method for producing a polyurethane, a known technique of a urethane reaction is used. For example, a polymer diol and a chain extender are mixed, preheated to about 40 ° C to 100 ° C, an organic diisocyanate is added, and the mixture is reacted at 50 ° C to 140 ° C for several hours. Are mixed and reacted at 20 to 140 ° C. for several hours to obtain a desired polyurethane. In the urethanization reaction, a normal urethanization reaction catalyst such as an organotin compound, an organotitanium compound, or a tertiary amine may be used, if desired. Further, the above reaction may be performed in the presence of an organic solvent inert to the organic diisocyanate.

When the reaction is carried out in the presence of an organic solvent,
Generally, the amount of the organic solvent used is adjusted so that the solid content at the end of the reaction is 5 to 90% by weight, especially 10 to 60% by weight.

The polyurethane used in the present invention may contain various additives such as those used in ordinary synthetic leather or artificial leather, depending on the purpose of use of the leather-like composite sheet. Examples of such additives include inorganic fillers, hiding agents, softeners, flame retardants, antioxidants, ultraviolet absorbers, dyes, surfactants, coagulation regulators, lubricants, and the like.

The polyethylene glycol used as the component B of the present invention has a number average molecular weight of 5,000 or more.
Preferably it is in the range of 6,000 to 30,000. 500
When it is less than 0, a leather-like sheet having a good texture and having a surface slimy touch, which is the greatest effect of the present invention, cannot be obtained. The number average molecular weight may be 5000 or more,
Usually, polyethylene glycol exceeding 30,000 is difficult to obtain industrially.

The amount of the polyethylene glycol is in the range of 5 to 20 parts by weight based on 100 parts by weight of the polyurethane of the component A. It is more preferably in the range of 5 to 15 parts by weight. If the amount is less than 5 parts by weight (based on 100 parts by weight of A), the obtained leather-like sheet cannot have a smooth slimy touch. When the blending amount was 20 parts by weight (based on A1
If the amount is more than (00 parts by weight), the durability of the obtained sheet-like material may deteriorate, or inconvenience may occur in the post-finishing process.

Examples of the water-miscible solvent used as the component C in the present invention include N, N-dimethylformamide,
N, N-dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, dioxane and the like can be mentioned. Among them, N, N-dimethylformamide is preferably used. Further, an amount of a non-water-miscible organic solvent that does not inhibit water miscibility may be used by mixing.

The fiber base material is a synthetic fiber such as polyamide,
Polyester, vinylon, polyacrylonitrile, etc.
Artificial fibers such as rayon, cupra, acetate or the like, or natural fibers such as knitted fabrics, woven fabrics and non-woven fabrics obtained from silk, cotton, wool, hemp, etc., are three-dimensionally entangled and have an average fineness of 0.1 denier or less. Any of fiber bundles and the like can be used.

Above all, average single fineness of three-dimensionally entangled 0.1
A nonwoven fabric made of an ultrafine fiber bundle of denier or less can be suitably used. The fiber base material was previously treated with a polyurethane resin so that the weight ratio of the ultrafine fiber bundle to the polyurethane was 70/30 to 97/3, and the apparent density was 0.4 to 0.8 g / cm ³ . An impregnated cloth is more preferred.

[0026]

The function of the leather-like sheet according to the present invention to be excellent in feeling, flexibility, cold resistance, heat resistance, durability and surface touch is not clear, but it has a specific structure. The blend of polyurethane and polyethylene glycol having a number average molecular weight of 5,000 or more is in an appropriate phase-separated state, and the above-mentioned preferable properties may be imparted to a leather sheet having the polyurethane blend as a skin layer. Conceivable. The leather sheet of the present invention thus obtained is useful for various uses such as clothing, shoes, bags, furniture, and miscellaneous goods.

[0027]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. In the examples, the compounds may be represented by the following abbreviations. DMF: N, N-dimethylformamide MDI: 4,4′-diphenylmethane diisocyanate EG: Ethylene glycol PMPA: Number average molecular weight 2,000 obtained by condensation polymerization of 3-methyl-1,5-pentanediol and adipic acid Polyester diol PHC: Polyhexylene carbonate diol having a number average molecular weight of 2,000 PCL: Polycaprolactone diol having a number average molecular weight of 2,000 PTG: Polytetramethylene glycol having a number average molecular weight of 2,000 PEG2000: Polyethylene glycol having a number average molecular weight of 2,000 PEG20000: Number average molecular weight 20,000 polyethylene glycol

Production Example of Polyurethane A polymer diol having the composition shown in Table 1 (numbers are g
Number) 1000 g, 93 g of EG and 2390 g of N, N-dimethylformamide (DMF) were charged into a three-necked flask equipped with a Dimroth condenser, and heated to obtain a homogeneous solution. Thereafter, 500 g of MDI was charged as an organic diisocyanate, and the mixture was heated at 80 ° C. under nitrogen atmosphere. The reaction was continued for about 8 hours. Further, 2390 g of DMF was added and diluted to give a concentration of 25% by weight.
Was obtained. The viscosity (Poise) at 30 ° C. of each solution is shown in Table 1.

[0029]

[Table 1]

Examples 1 to 3 and Comparative Examples 1 to 4 Each of the obtained polyurethane solutions was blended according to the composition shown in Table 2, and as an additive, an alcohol-modified silicone oil was mixed with polyoxyethylene and polyoxypropylene block copolymer. A mixture having a weight ratio of 0.5: 1 was used in an amount of 15% by weight based on the polyurethane solid content, and a carbon black-containing vehicle (manufactured by Dainichi Seika Co., Ltd., Seika Seven BS-780 Black) was used as a colorant based on the polyurethane solid content. A polyurethane composition liquid was prepared by adding 50% by weight. The prepared liquid was treated with an average single fineness of 0.08.
Dr. polyethylene propylene adipate /
A porous fibrous material having a thickness of 1.2 mm and an apparent density of 0.42 g / cm ³ , in which a polyurethane obtained by polymerizing 4,4′-diphenylmethane diisocyanate / ethylene glycol at an equivalent ratio of 1/5/4 is contained in a porous state. 350g for base
/ M ² was applied by knife coating and subsequently poured into water at a temperature of 25 ° C. to solidify. The obtained coagulated product is
After removing the solvent in hot water at 0 ° C., washing, and then drying, a sheet-like material comprising a porous polyurethane layer and a fibrous substrate was obtained.

The obtained sheet was subjected to surface treatment and embossing to obtain a leather-like sheet with silver. The texture, drapability, stickiness and sliminess of these leather-like sheets were evaluated. 95% relative humidity, 7 temperature
A jungle test was performed in which the sample was kept at 0 ° C. for 5 weeks. Table 2 shows the results.

[0032]

[Table 2]

Symbols in the table are: ：: good or no change ×: bad or sticky

The leather-like sheets of Examples 1 to 3 of the present invention had a uniform polyurethane porous layer and a smooth surface. Furthermore, the touch on the surface was free of stickiness and excellent in slimy feeling. The results of the wet heat test were also good. The leather-like sheet material of Comparative Example 1 was excellent in texture and wet heat test, but had a sticky surface and was poor in sliminess. Comparative Example 2 is a leather-like sheet which does not use high-molecular-weight polyethylene glycol which is an essential component of the present invention. It was excellent in texture and wet heat test, but had no slimy touch on the surface. Comparative Example 3 is a leather-like sheet obtained by blending a high molecular weight polyethylene glycol, which is an essential component of the present invention, in a larger amount than the range specified in the present invention. In this product, the wax-like material was migrated to cause unevenness, and the result of the wet heat test was also poor. Comparative Example 4 is a leather-like sheet obtained by blending polyethylene glycol having a molecular weight of 2,000. This one had a sticky surface and a poor slimy feel.

[0035]

The leather-like sheet material of the present invention has a slimy feeling particularly with a light surface touch and is excellent in texture, drape property and durability.
It can be applied as a material for interiors, bags, bags, shoes, and the like.

Claims (1)

(57) [Claims] 1. A. First Embodiment Polyester, polycarbonate,
Number average molecular weight selected from the group consisting of polylactones is 5
B. a polyurethane obtained by reacting a polymer diol of from 0.00 to 3000 with an organic diisocyanate and a low molecular chain extender; B. 5 to 20 parts by weight of polyethylene glycol having an average molecular weight of 5,000 or more (based on 100 parts by weight of A); A leather-like sheet obtained by impregnating or / and applying an organic solvent solution comprising a water-miscible organic solvent onto a fiber base material and coagulating with a non-solvent of the polyurethane of component A.