JPH059875A - Production of leather-like composite sheet-like article - Google Patents

Abstract

(57) [Summary] [Purpose] Excellent texture, flexibility and durability, cold resistance,
Provided is a leather-like composite sheet material having excellent heat resistance. [Structure] The polymer diol component is 2-methyl-1,
The weight ratio of the polycarbonate diol containing an alkanediol unit derived from 8-octanediol or 1,9-nonanediol and a carbonyl unit to the polyoxyethylene ether diol is 60/40 to 90/10.
The organic solvent solution of polyurethane is applied to the fibrous substrate and coagulated with the non-solvent of polyurethane.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a leather-like composite sheet. More specifically, the present invention relates to a leather-like composite sheet comprising a polyurethane foam layer containing a polycarbonate diol component having a specific structure and a polyether diol component as essential components and a fibrous substrate.

The leather-like composite sheet of the present invention has particularly excellent flexibility, feel and drape, and also has durability, cold resistance and heat resistance, so that it can be used for medical treatment, interior decoration,
It is useful as a material for bags, bags and shoes.

[0003]

2. Description of the Related Art Conventionally, various so-called silver-like or suede-like synthetic leathers and artificial leathers have been known as leather-like composite sheet materials comprising a fibrous substrate and a polyurethane resin.

When excellent durability is required, an example using a polycarbonate polyurethane as the polyurethane resin is known. For example, Japanese Patent Publication Sho-63-54
Japanese Patent No. 833 discloses the content of a synthetic leather sheet material using a polycarbonate-based polyurethane elastomer having excellent light resistance and hydrolysis resistance, and a method for producing the same. In addition, Japanese Patent Laid-Open No. 2-33384 discloses that
By using a polycarbonate-based polyurethane obtained by reacting a polycarbonate-based polyol containing a methyl-1,8-octanediol unit with an organic diisocyanate and a chain extender as a skin material, synthesis with good flexibility and hydrolysis resistance is achieved. It is described that leather can be produced.

[0005]

There is a remarkable tendency in recent years toward the trend of upsizing in consumer life and the emphasis on sensitivity and fashion, and even in the case of leather-like sheet materials such as synthetic leather and artificial leather, it has hitherto been difficult. Demands for properties that have not been requested are becoming stricter.
The present inventors examined the flexibility, feel, and durability of the leather-like composite sheet material, and found that the above-mentioned JP-A-63-548.
Although the polycarbonate polyurethane resin is used in Japanese Patent No. 33, it is substantially used only as a top coat because the resin is hard. In addition, Japanese Patent Laid-Open No. 2-3
Obtained by coating a fibrous substrate with an organic solvent solution of polyurethane obtained by reacting a polycarbonate diol as described in 3384 with a chain extender and an organic diisocyanate, followed by coagulation in water. The leather-like sheet was excellent in durability, but because the long-chain alkylene glycol is used and the polarity is low, the layer made of the polyurethane elastomer partially fails to foam, resulting in a feeling, The drape was still unsatisfactory. It is generally well known that polyether-based polyurethane has excellent hydrolysis resistance but poor light resistance and heat deterioration resistance.

The object of the present invention is to produce a leather-like composite sheet comprising a fibrous substrate and a polyurethane elastomer porous layer, which is particularly excellent in flexibility, texture and drape, and is also excellent in moist heat resistance and heat deterioration resistance. To provide a method.

[0007]

According to the present invention, the above-mentioned object is (A) 1,8-, which may be substituted with a methyl group.
A polycarbonate diol containing an alkanediol unit and a carbonyl unit derived from at least one alkanediol having 8 to 10 carbon atoms selected from the group consisting of octanediol and 1,9-nonanediol,
(B) A polyether diol composed of a polyoxyethylene compound having hydroxyl groups at both ends, a chain extender, and an organic diisocyanate in a weight ratio of (A) / (B) = 60/4.
It is achieved by applying a solution of polyurethane in an organic solvent obtained by copolymerization at a ratio of 0 to 90/10 to a fibrous substrate and coagulating with a non-solvent of polyurethane.

First, the polymer diol as the component (A) used in the present invention will be described. The polycarbonate diol used in the present invention (hereinafter referred to as the polycarbonate diol (A)) has the above-mentioned specific alkanediol unit and carbonyl unit as essential constitutional units, and has an average molecular chain terminal. It has two or more alcoholic hydroxyl groups.

The specific alkanediol unit, which is one of the essential constituent units of the polycarbonate diol (A), may be substituted with one methyl group 1,8-
A unit in the form of removing two hydrogen atoms contained in two hydroxyl groups from at least one alkanediol having 8 to 10 carbon atoms selected from the group consisting of octanediol and 1,9-nonanediol (hereinafter, Such a unit is referred to as an alkanediol unit (I)) and has the general formula

[0010]

[Chemical 1]

(In the formula, R represents a hydrogen atom or a methyl group, m represents an integer of 0 to 4, and n represents an integer of 4 to 8, where m
And n are assumed to be 7 or 8).
The alkanediol unit (I) has the formula

[0012]

[Chemical 2]

The 2-methyl-1,8-octanediol unit represented by (hereinafter referred to as MOD unit) and / or the 1,9-nonanediol unit represented by the formula --O-(CH ₂ ) ₉ --O-- It is desirable that the leather-like sheet-like product is flexible and has particularly excellent wet heat resistance and heat deterioration resistance. When the alkanediol unit represented by Chemical formula 1 has less than 8 carbon atoms, durability, particularly wet heat resistance, may deteriorate. If the carbon number is larger than 10, the feel, drape, etc., which is the object of the present invention, may deteriorate.

The MOD unit and the ND unit contained in the alkanediol unit (I) may be only one of them or may be both of them. Including both MOD units and having a molar ratio of ND units to MOD units of 90/1
Within the range of 0-10 / 90, especially 80 / 20-20 /
It is generally preferable that the ratio is within the range of 80 because the obtained leather-like sheet material often has particularly good feeling and flexibility.

The polycarbonate type diol (A) may contain one or more kinds of diol units other than the alkanediol unit (I) as long as the effects of the present invention are not impaired. Examples of such diol units include saturated aliphatic diols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol and neopentyl glycol;
Examples include a unit in which two hydrogen atoms contained in two hydroxyl groups are removed from a saturated alicyclic diol such as 4-cyclohexanediol and a diol such as a divalent aromatic alcohol such as xylylene glycol. ..

The polycarbonate diol has a number average molecular weight of 500 to 1000 determined on the basis of the hydroxyl value.
Those in the range of 0 are desirable, and especially 800 to 500
When it is in the range of 0, the handling property of the polycarbonate diol (A) and the polyurethane obtained therefrom will be good, and the flexibility and drapeability of the obtained leather-like composite sheet will be particularly good in some cases. It is preferable because it is abundant.

The method for producing the polycarbonate diol (A) in the present invention is not particularly limited,
Known polycarbonate production means can be applied.
For example, the polycarbonate diol (A) is a diol having a structure corresponding to the diol unit of Chemical formula 1, and an alkylene carbonate such as ethylene carbonate,
Diaryl carbonate such as diphenyl carbonate, carbonic acid ester such as dialkyl carbonate such as diethyl carbonate, dimethyl carbonate or the like is used at a desired ratio to react, or the diol and phosgene are used at a desired ratio to react. Manufactured.

Next, the polyether diol (B) composed of a polyoxyethylene compound having hydroxyl groups at both ends used in the polyurethane constituting the present invention will be described.
Examples of the polyoxyethylene compound having hydroxyl groups at both ends used in the present invention include low molecular diols, amines, dihydric phenols, dicarboxylic acids, and other active hydrogen-containing substances to which ethylene oxide is added. Examples of the low molecular weight diol include ethylene glycol and 1,4-
Butanediol, 1,6-hexanediol, 1,9-
Nonanediol, neopentyl glycol, 3-methyl 1,5-pentanediol, 2-methyl-1,8-octanediol and the like can be mentioned. Examples of amines include aliphatic amines such as methylamine, ethylamine, isopropylamine, decylamine, and allylamine, alicyclic amines such as piperazine, and alkanolamines such as diethanolamine. Examples of the dihydric phenol include catechol, resorcin, hydroquinone and the like. Examples of the dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid and terephthalic acid. These active hydrogen-containing compounds can be used alone or in combination of two or more.

The method for adding ethylene oxide to the active hydrogen-containing compound may be a conventional method. Further, in the present invention, an alkylene oxide other than ethylene oxide may be added in a block or random manner within a range that does not impair the flexibility and drapability which are the features of the invention. In this case, the amount of alkylene oxide other than ethylene oxide is preferably less than 20% by weight of all oxides. Examples of such alkylene oxide include propylene oxide, butylene oxide, and styrene oxide, and one or two of these can be used.

The polyoxyethylene compound having hydroxyl groups at both ends used in the present invention preferably has a number average molecular weight of 500 to 10,000 as determined on the basis of the hydroxyl value. In particular, when it is in the range of 800 to 5000, the handling properties of the polyoxyethylene compound containing hydroxyl groups at both ends and the polyurethane obtained therefrom are good, and the flexibility, drape property and durability of the obtained leather-like composite sheet are good. Both are preferable because they are often particularly good.

The ratio of the above-mentioned polymer diols (A) and (B) is in the range of 60/40 to 90/10 by weight so that the foamed state of the layer made of the polyurethane elastomer will be good. It is also preferable from the viewpoint of feeling, drape property, and durability. More preferably (A) /
(B) = 60/40 to 80/20. (A)
If the weight ratio (A) / (B) of (B) and (B) is less than 60/40, the durability of the leather-like composite sheet becomes poor, and the polyurethane in the leather-like sheet obtained by coagulating in water is obtained. The porous layer will be crushed when dried. When the weight ratio (A) / (B) of (A) and (B) is more than 90/10, the polyurethane porous layer in the leather-like sheet obtained by coagulating in water has an unfoamed portion. And the drapeability deteriorates. Also, the texture will be hard.

The organic diisocyanate used for producing the polyurethane elastomer in the present invention may be an organic diisocyanate as used for producing ordinary polyurethanes. Examples of such organic diisocyanates include aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-
Examples thereof include aliphatic or alicyclic diisocyanates such as dicyclohexylmethane diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated xylylene diisocyanate. Among these organic diisocyanates, 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, etc. are particularly advantageous in industrial use because of their high versatility. ..

In the present invention, a polymer diol, an organic diisocyanate, and a chain extender are used to produce a polyurethane elastomer. The chain extender may be any chain extender such as used for the production of ordinary polyurethanes, and is usually a low molecular weight compound having a molecular weight of 400 or less and having two or more active hydrogen atoms in the molecule. used. Typical examples of such low molecular weight compounds include ethylene glycol, propylene glycol,
1,4-butanediol, 1,6-hexanediol,
Aliphatic diol such as 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, alicyclic diol such as 1,4-cyclohexanediol, xylylene glycol Such as 2
-Valent aromatic diols, polyethylene glycols such as diethylene glycol, dipropylene glycol, dibutylene glycol, triethylene glycol and tripropylene glycol, carboxyl group-containing diols such as dimethylolpropionic acid, ethylenediamine, propylenediamine, xylylenediamine, isophorone Aliphatic, alicyclic or aromatic diamines such as diamine, phenylenediamine and tolylenediamine, heterocyclic compounds containing two imino groups such as piperazine in the cyclic structure, adipic acid dihydrazide, isophthalic acid dihydrazide, etc. And trihydric alcohols such as dihydrazide, hydrazine, trimethylolpropane, pentaerythritol, and glycerin. These chain extenders include at least the above-mentioned diols, diamines, heterocyclic compounds containing two imino groups in the cyclic structure, dihydrazides, hydrazines and other low-molecular compounds having two active hydrogen atoms in the molecule. It is general to use one kind alone or in combination with at least one kind of the above-mentioned trivalent or higher alcohol. The amount of the chain extender used is usually 30% by weight or less based on the obtained polyurethane,
The amount is preferably within the range of 1 to 25% by weight.

Regarding the solution viscosity of the polyurethane used in the present invention, in order to improve the feel, drape and durability of the leather-like composite sheet, the solid content concentration in the dimethylformamide solvent measured at 30 ° C. It is generally preferred that the 25 wt% solution has a viscosity of 5 to 2000 poise, especially 50 to 1000 poise.

With regard to the specific operation method for producing polyurethane, the known urethanization reaction technique is used. For example, the above-mentioned polycarbonate diol (A), a polymer polyol such as polyalkylene glycol and a chain extender are mixed and preheated to about 40 to 100 ° C., and then an organic diisocyanate is added to 50 to 14
The reaction is carried out at 0 ° C. for several hours, and if necessary, the same or different chain extender as that already used is mixed,
The desired polyurethane elastomer is obtained by reacting at 0 ° C. for several hours. In the urethanization reaction, a usual urethanization reaction catalyst such as an organotin compound, an organotitanium compound, and a tertiary amine may be used if desired. Further, the above reaction may be carried out in the presence of an organic solvent which is inert to the organic diisocyanate. Examples of the organic solvent include aromatic hydrocarbons such as toluene, esters such as ethyl acetate, amides such as dimethylformamide, methyl ethyl ketone, methyl isobutyl ketone, ketones such as acetone, cyclic ethers such as tetrahydrofuran, trichloroethylene, etc. The halogenated hydrocarbons and the like are used alone or in an arbitrary mixture. These exemplified organic solvents may be used as a mixture with alcohols such as isopropanol, ethanol and methanol.

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

The fibrous base material constituting the leather-like sheet material of the present invention is a two-dimensional fiber aggregate such as a woven fabric, a knitted fabric or a non-woven fabric, which is used for producing ordinary synthetic leather and artificial leather. Alternatively, it is a three-dimensional fiber aggregate. The fibers constituting the fiber substrate include natural fibers such as cotton, hemp and wool, regenerated fibers such as viscose rayon fibers, copper ammonia rayon fibers, semi-synthetic fibers such as acetate fibers, polyamide fibers (nylon 6 fibers, nylon 66). Fiber, aromatic nylon fiber, etc.), polyvinyl alcohol fiber, polyvinylidene chloride fiber, polyester fiber, polyacrylonitrile fiber, polyurethane fiber, synthetic fiber such as poly (alkylene paraoxybenzoate) fiber, etc. Among them, cotton, polyamide fiber (nylon 6 fiber, nylon 66 fiber, aromatic nylon fiber, etc.), polyvinyl alcohol fiber,
Polyester fiber, polyurethane fiber and the like are preferably used. These fibers may be ordinary fibers, or may be specially shaped fibers such as fine fibers and porous fibers. The fibrous substrate may be obtained by impregnating the above fiber assembly with an elastic polymer such as polyurethane elastomer.

The leather-like sheet material of the present invention comprises a fibrous substrate coated with a layer comprising a polyurethane resin.
It may have any of the forms of so-called silvery tone and polymer suede tone. In a leather-like composite sheet having a form in which a layer made of polyurethane is coated on a fibrous substrate, an adhesive layer and / or a mesothelial layer are provided between the layer made of polyurethane and the fibrous substrate. Good. Polyurethane, for example, is preferably adopted as the resin forming the adhesive layer or the inner skin layer.

The polyurethane used in the present invention may be blended with various additives as 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 substance fillers, masking agents, softeners, antioxidants, ultraviolet absorbers, dyes, surfactants, coagulation regulators, lubricants and the like.

The leather-like sheet material of the present invention can be produced according to a known method such as a wet coagulation method which is adopted for producing ordinary synthetic leather and artificial leather. As a method for producing a leather-like sheet material by a wet method, for example, a solution of polyurethane is applied to a fibrous substrate and then a porous layer made of the polyurethane is formed by immersing in a nonsolvent of the polyurethane, A method comprising washing with water and drying can be mentioned.

If desired, the leather-like sheet material of the present invention may be subjected to various post-treatments such as those employed for ordinary synthetic leather and artificial leather. Examples of such post-treatment include embossing treatment, rubbing treatment, wrinkling treatment, softening agent treatment, top coat for texture improvement, coloring, surface characteristic improvement and the like.

[0032]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, compounds may be represented by the following abbreviations. EG: ethylene glycol MOD: 2-methyl-1,8-octanediol ND: 1.9-nonanediol MDI: 4,4'-diphenylmethane diisocyanate PEG: polyethylene glycol having a number average molecular weight of 2000 PPG: polypropylene having a number average molecular weight of 2000 Glycol PTG: Polytetramethylene glycol with a number average molecular weight of 2000 PNOC: Polycarbonate diol with a number average molecular weight of 2000 obtained by condensation polymerization of an equimolar mixture of ND and MOD and ethylene carbonate PHC: Hexanediol and ethylene carbonate Number average molecular weight 20 obtained by condensation polymerization of and
00 polycarbonate diol

Examples 1 to 3 and Comparative Examples 1 to 7 1000 g of a polymer diol having the composition shown in Table 1 and EG
93 g and N, N'-dimethylformamide (DMF)
After charging 2390 g into a three-necked flask equipped with a Dimroth condenser and heating to make a homogeneous solution, 500 g of MDI as an organic diisocyanate was charged, and the mixture was heated under a nitrogen atmosphere to 80
The reaction was carried out at ℃ for about 8 hours. Furthermore, DMF2390g
Was added and diluted to obtain a polyurethane solution having a concentration of 25% by weight. The viscosity (poise) at 30 degrees of each solution is shown in Table 1. 13% by weight of each obtained polyurethane solution with DMF
And a mixture of alcohol-modified silicone oil and polyoxyethylene / polyoxypropylene block copolymer in a weight ratio of 0.5: 1 as an additive in an amount of 15% by weight based on the polyurethane solid content, and coloring. A polyurethane composition liquid was prepared by adding a vehicle containing carbon black (manufactured by Dainichiseika Co., Ltd., Seika Seven BS-1780-5 Black) as an agent in an amount of 50% by weight relative to the polyurethane solid content. The obtained preparation liquid was applied to the raised surface of a polyester and rayon mixed woven fabric by knife coating to a thickness of 1.0 mm, and then the temperature was 25 ° C.
It was immersed in water and solidified. The obtained solidified product is heated to 80 ° C.
After removing the solvent in hot water, washing, and drying, a sheet-like material comprising a porous polyurethane layer and a fibrous substrate was obtained.

The sheet-like material obtained was subjected to surface treatment and embossing to obtain a leather-like composite sheet with silver. These leather-like composite sheet-like materials were sponge-like in the polyurethane porous layer, texture, drapability, and a heat deterioration test of leaving for 1 week in an atmosphere of 130 ° C., relative humidity of 95%, temperature of 70 ° C. The jungle test was carried out for 10 weeks. The evaluation results are shown in Table 1.

[0035]

[Table 1] The symbols in the table are ◯: Good or unchanged x: Poor or sticky or cracked

The leather-like composite sheet materials of Examples 1 to 3 of the present invention each have a uniform sponge structure in which the polyurethane porous layer has long pores extending in a direction substantially perpendicular to the surface, The surface was smooth. It was a leather-like composite sheet with a soft texture and excellent drapeability, high blackness, and a high-class feeling. The leather-like composite sheet-like product of Comparative Example 1 was inhomogeneous with a polyurethane foam layer containing a giant foamed portion, was inferior in surface smoothness, and had poor feel and touch. Each of the leather-like composite sheet-like products of Comparative Examples 2 to 7 has a non-porous portion due to a partial foaming defect in the polyurethane porous layer, which is inferior in surface smoothness, inferior in feel and drape. Was there. Particularly, in Comparative Examples 5 and 6, the polyurethane itself was hard and had a poor feel and poor drapeability.

The leather-like composite sheet materials of Examples 1 to 3 and Comparative Examples 2, 3 and 5 to 7 containing a large amount of the polycarbonate diol component were all good in the jungle test and the heat deterioration test without stickiness or cracking. Was, but P
The leather-like composite sheet material of Comparative Example 4 in which PG was copolymerized was good in the jungle test, but was greatly deteriorated such as cracks in the heat deterioration test. In addition, PEG
In the leather-like composite sheet of Comparative Example 1 containing many components, stickiness due to deterioration of polyurethane occurred in both the jungle test and the heat deterioration test. From these results, the leather-like composite sheet material of the present invention has excellent coagulability when forming a porous layer, texture, and excellent drapeability,
It can be seen that it is a leather-like composite sheet that is excellent in heat deterioration resistance and jungle resistance test.

[0038]

INDUSTRIAL APPLICABILITY The leather-like composite sheet of the present invention is particularly excellent in flexibility, feeling, and drape, and has long-term durability even under adverse conditions such as high temperature and high humidity. It is excellent and can be used under conditions that could not be used as materials for medical treatment, interiors, bags, bags, shoes, etc., and the range of applications is expanded.

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Claims (1)

Claims: 1. (A) At least one carbon atom selected from the group consisting of 1,8-octanediol and 1,9-nonanediol optionally substituted with a methyl group, having 8 to 8 carbon atoms.
Polycarbonate diol containing alkanediol unit derived from 10 alkanediol and carbonyl unit, (B) polyether diol consisting of polyoxyethylene compound having hydroxyl groups at both ends, chain extender and organic diisocyanate in weight ratio And (A) / (B) =
A method for producing a leather-like composite sheet, which comprises applying a solution of polyurethane in an organic solvent obtained by copolymerization at a ratio of 60/40 to 90/10 to a fibrous substrate and coagulating with a non-solvent of polyurethane. ..