JP3103406B2 - Polyurethane composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention relates to polyurethane compositions. More specifically, the present invention relates to a composition comprising a polyester having a specific structure and a polyurethane having a specific structure. The polyurethane composition of the present invention is applicable to synthetic leather, artificial leather, and the like.When used as a skin layer or an intermediate layer, the polyurethane composition has excellent sensibility such as flexibility, feeling, drape property, and durability and cold resistance. Those having excellent properties such as heat resistance and heat resistance can be obtained.

[0002]

2. Description of the Related Art Conventionally, various modifications of polyurethane used for a skin layer or an intermediate layer have been performed to obtain synthetic leather or artificial leather having excellent sensitivity and physical properties.
For example, when cold resistance and hydrolysis resistance are required, a polyether-based polyurethane is used. Further, Japanese Patent Application Laid-Open No. 2-33384 discloses that a polyurethane having a specific structure is used to obtain a synthetic leather having an excellent feeling.

[0003]

There has been a remarkable tendency in recent years to focus on luxury and fashionability in consumer life, and even in leather-like sheet materials used as synthetic leather and artificial leather, Demands for characteristics that have not been required in the past have become severe.
The present inventors examined the flexibility and hand of the leather-like composite sheet, and found that the polyether-based urethane or the polyurethane having a specific structure as described in JP-A-2-33384 was used. Even so, the flexibility, feeling and touch of the obtained leather sheet were not yet satisfactory. When trying to pursue flexibility, feeling, touch, etc. using these polyurethanes,
In addition to reducing the number of hard segments in the polyurethane, durability is deteriorated as a result. The object of the present invention is applicable to synthetic leather, artificial leather and the like, and when used as a skin layer or an intermediate layer, has excellent sensitivity, flexibility, feeling, touch, etc., and also has durability, cold resistance, heat resistance. An object of the present invention is to provide a polyurethane composition from which a material having excellent properties such as properties can be obtained.

In accordance with the present invention, the above objects have been described. General formula 2

Embedded image (Wherein, m and n are positive integers, the sum of which is 4 or more and 8 or less ), and obtained by polycondensation with an aliphatic dicarboxylic acid or an ester-forming derivative thereof, 5 to 30% by weight of a polyester having a number average molecular weight of 700 to 5000; At least one alkanediol having 8 to 10 carbon atoms selected from the group consisting of 1,8-octanediol and 1,9-nonanediol which may be substituted with a methyl group, and an aliphatic dicarboxylic acid or an ester-forming derivative thereof A polyurethane composition comprising 70 to 95% by weight of a polyurethane obtained by reacting a polyester diol obtained by polycondensation with a polyester diol, a diisocyanate and a chain extender, to a skin layer or an intermediate layer of synthetic leather or artificial leather. Achieved by

First, the polyester of the component A used in the present invention will be described. The polyester used in the present invention mainly comprises a specific diol having 6 to 10 carbon atoms represented by the above formula 2, and is obtained by polycondensation with an aliphatic dicarboxylic acid. When the carbon number of the diol is smaller than 6, the durability, particularly the wet heat resistance, may be deteriorated. If the number of carbon atoms is more than 10, cold resistance, flexibility and the like may be deteriorated. Specific examples of the diol represented by Chemical formula 2 used in the present invention include 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, and the like. These diols may be used alone or as a mixture. Further, the above-mentioned formula (2) may be used within the range not impairing the flexibility, hand, touch, durability and the like which are the objects of the present invention.
Although low molecular diols other than those represented by the formula (1) may be used as a mixture, the amount thereof should be 10% by weight or less.

Examples of the aliphatic dicarboxylic acid used for producing the polyester used in the present invention include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid and the like. These aliphatic dicarboxylic acids may be used as a mixture if necessary. The lower alkyl ester derived from the aliphatic dicarboxylic acid is mentioned as an example of the ester-forming derivative of the aliphatic dicarboxylic acid. The method for producing the polyester is not particularly limited, and known polyester condensation polymerization means can be applied. It is important that the number average molecular weight of the polyester of the component A used in the present invention is in the range of 700 to 5,000. If the molecular weight is less than 700, the bleeding property, cold resistance, etc. may be deteriorated.
If it is larger than 000, workability, feeling, touch and the like may be deteriorated.

Next, the polyurethane of the component B used in the present invention will be described. The polyester diol used for producing the polyurethane of the component B is at least one kind of carbon having 8 carbon atoms selected from the group consisting of 1,8-octanediol and 1,9-nonanediol which may be substituted with one methyl group. To 10 are obtained by polycondensing an alkanediol of 10 to an aliphatic dicarboxylic acid or an ester-forming derivative thereof. The alkanediol has the general formula 3

[0008]

Embedded image (Wherein, R represents a hydrogen atom or a methyl group, p and q represent 0
Alternatively, it represents a positive integer, and the sum of p and q is 7 or 8. ).

The alkanediol has the formula

Embedded image

2-methyl-1,8-octanediol (hereinafter referred to as MOD) and / or the formula HO
- (CH ₂₎ be a 1,9-diol represented by ₉ -OH (hereinafter referred to as ND), flexibility, desired from the viewpoint of durability. In the alkane diol represented by Chemical Formula 3, if the number of carbon atoms is less than 8, durability, particularly resistance to moist heat may deteriorate. On the other hand, if the number of carbon atoms is larger than 10, the feeling, touch and the like, which are objects of the present invention, may be deteriorated.

[0011] The MOD and ND contained in the alkanediol may be only one of them, or both, but include both ND and MOD as the alkanediol, and include both ND and MOD. Has a molar ratio of 9
0/10 to 10/90, especially 80/20 to
It is generally preferred that the ratio be in the range of 20/80, since flexibility and feeling are particularly good in many cases. Further, one or more diols other than the alkanediol represented by Chemical Formula 3 may be contained as long as the effects of the present invention are not impaired. Examples of the diol include saturated aliphatic diols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and neopentyl glycol;
Examples include diols such as saturated alicyclic diols such as 4-cyclohexanediol and divalent aromatic alcohols such as xylylene glycol.

Examples of the aliphatic dicarboxylic acid which reacts the above diol include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid and the like. These aliphatic dicarboxylic acids may be used as a mixture if necessary. The lower alkyl ester derived from the aliphatic dicarboxylic acid is mentioned as an example of the ester-forming derivative of the aliphatic dicarboxylic acid. The method for producing the polyester is not particularly limited, and known polyester condensation polymerization means can be applied. The polyester diol desirably has a number average molecular weight in the range of 500 to 10,000, and particularly in the range of 700 to 5,000, so that the polyurethane as the component B has good handleability, and also has flexibility, It is preferable because durability and the like are often good.

Examples of the diisocyanate constituting the polyurethane of the component B include aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, and xylylene diisocyanate; hexamethylene diisocyanate, isophorone diisocyanate, and 4,4 '. -Aliphatic or alicyclic diisocyanates such as dicyclohexylmethane diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated xylylene diisocyanate. Among these organic diisocyanates, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, etc. are particularly advantageous for industrial use because of their high versatility.

Next, the chain extender constituting the polyurethane of the component B will be described. The chain extender may be any chain extender as used for the production of ordinary polyurethane, and a compound having a molecular weight of 400 or less and having two or more active hydrogen atoms in one molecule is usually used. Representative examples of such compounds include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol,
Aliphatic diols such as 1,9-nonanediol and 2-methyl-1,8-octanediol; alicyclic diols such as 1,4-cyclohexanediol; divalent aromatic diols such as xylylene glycol; diethylene glycol; Propylene glycol, dibutylene glycol,
Polyalkylene glycols such as triethylene glycol and tripropylene glycol; carboxyl group-containing diols such as dimethylolpropionic acid; aliphatic and alicyclic such as ethylenediamine, propylenediamine, xylylenediamine, isophoronediamine, phenylenediamine and tolylenediamine Or a heterocyclic compound containing two imino groups such as aromatic diamine and piperazine in a cyclic structure, dihydrazide such as adipic dihydrazide and isophthalic dihydrazide, hydrazine, trimethylolpropane, pentaerythritol and glycerin. Alcohols having a valency or higher. Generally, at least one of these chain extenders is used alone, or in combination with at least one of the above-mentioned trihydric or higher alcohols. The amount of the chain extender to be used is usually 30% by weight or less based on the obtained polyurethane, and preferably 1 to 25% by weight.

With respect to a specific operation method for producing the polyurethane of the component B, a known technique of a urethane reaction is used. For example, after mixing the above-mentioned polyester diol and a chain extender and preheating to about 40 to 100 ° C., adding an organic diisocyanate, and reacting at 50 to 140 ° C. for several hours, and if necessary, the same or different as described above. A desired polyurethane can be obtained by mixing a chain extender and reacting at 20 to 140 ° C. for several hours. In the urethanization reaction, if desired, a normal urethanization reaction catalyst, for example, an organic tin compound, an organic titanium compound,
Tertiary amine compounds and the like may be used. Further, the above reaction may be carried out in the presence of an organic solvent inert to the organic diisocyanate. Examples of organic solvents include aromatic hydrocarbons such as toluene; esters such as ethyl acetate;
Amides such as dimethylformamide; ketones such as methyl ethyl ketone, methyl isobutyl ketone and acetone; cyclic ethers such as tetrahydrofuran; halogenated hydrocarbons such as trichloroethylene are used alone or as a mixture. These exemplified organic solvents may be used by mixing 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 is generally adjusted so that the solid content at the end of the reaction is 5 to 90% by weight, especially 10 to 60% by weight. is there.

The polyurethane of the component B constituting the present invention may have a viscosity of 5 to 2,000 poise when a solution having a solid content of 25% by weight in dimethylformamide solvent is considered to be applied to synthetic leather or artificial leather. preferable. The component A and the component B constituting the polyurethane composition of the present invention are compounded in an amount of 5 to 30% by weight of the component A and 70 to 95% of the component B.
It is important to be in the weight percent range. When the blending amount of the polyester having the specific structure of the component A is less than 5% by weight, flexibility, feeling,
Touch may be insufficient, and if it is more than 30% by weight, durability may be deteriorated.

As an example of application to synthetic leather or artificial leather, there is a case where the polyurethane composition of the present invention is used as an intermediate layer and / or a skin layer on a fibrous substrate. In this case, an adhesive layer may be interposed between the fibrous substrate and the layer comprising the polyurethane composition of the present invention.
For example, polyurethane or the like is suitably used as a resin constituting the adhesive layer. Various additives can be blended in the polyurethane composition of the present invention according to the purpose of use. Such additives include, for example, inorganic fillers, hiding agents, softeners, antioxidants. UV absorber,
Dyes, pigments, lubricants and the like can be mentioned.

[0018]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, the compounds may be represented by the following abbreviations. EG: ethylene glycol NPG: neopentyl glycol BD: 1,4-butanediol MPD: 3-methyl-1,5-pentanediol HD: 1,6-hexanediol MOD: 2-methyl-1,8-octanediol ND : 1,9-nonanediol AdA: adipic acid PPG: polypropylene glycol having a number average molecular weight of 2000 PTG: polytetramethylene glycol having a number average molecular weight of 2000 PNOA: condensation polymerization of an equimolar mixture of ND and MOD with adipic acid. MDI: 4,4'-diphenylmethane diisocyanate having a number average molecular weight of 2,000
G

Preparation Example of Polyester 153 g of 3-methyl-1.5-pentanediol, 146 g of adipic acid (MPD / AdA molar ratio 1,3 / 1)
Was subjected to esterification while distilling condensed water at a temperature of about 195 ° C. while passing nitrogen gas under normal pressure. After the acid value was reduced to 1 or less, the degree of vacuum was gradually increased by a vacuum pump, and polycondensation was performed to obtain polyester PMPA ₂₀₀₀ . The number average molecular weight of the obtained polyester was 2,000. Polycondensation was similarly performed using the diols shown in Table 1 to obtain the polyesters shown in Table 1.

[0020]

[Table 1]

Production Example of Polyurethane 1000 g of PNOA having a number average molecular weight of 2000, EG62
g and N, N-dimethylformamide (DMF) 21
55 g was charged into a three-necked flask equipped with a Dimroth condenser and heated to obtain a homogeneous solution. Then, 375 g of MDI was charged as an organic diisocyanate, reacted at 80 ° C. for about 8 hours in a nitrogen atmosphere, and further diluted with 2156 g of DMF. And a 25% by weight polyurethane solution (a)
I got The viscosity of the solution at 30 ° C. was 450 poise. The same reaction was carried out with the raw materials and compositions shown in Table 2 to obtain polyurethane solutions (b) to (d) having a concentration of 25% by weight.

[0022]

[Table 2]

To 360 g of the polyurethane solution (a), 90 g of methyl ethyl ketone, 10 g of PMPA ₂₀₀₀ , and 15 g of titanium oxide were added and thoroughly dispersed to prepare a coating solution, and then coated on a release paper having pores to obtain a film having a thickness of about 30 μm. Was. After a two-component adhesive was applied on this film, the film was bonded to the raised surface of a blended woven fabric of polyester and rayon, and then dried to obtain a sample. The obtained bonded sample was further cured at 50 ° C. for 3 days and aged to obtain a leather-like sheet. The hand and touch of these leather-like sheets were examined, and further subjected to a heat deterioration test in which they were left for 1 week in an atmosphere of 130 ° C., and a relative humidity of 95%.
A jungle test was performed in which the sample was kept in an atmosphere at a temperature of 70% for 5 weeks. Table 3 shows the evaluation results. The symbols in the table are ◎: very good: good or no change Δ: inferior to ×: bad or sticky.

Example 2, Comparative Examples 1 to 11 A coating solution was prepared in the same manner as in Example 1 so that the polyurethane and polyester had the compositions shown in Table 3, and a leather-like sheet was obtained in the same manner. Table 3 shows the results of these evaluations.

[0025]

[Table 3]

The leather-like sheet prepared using the polyurethane compositions of Examples 1 and 2 of the present invention shows no change even after the heat deterioration test and the jungle test, and has excellent durability. Recognize. In addition, the feeling was very good, and the touch was good with a little feeling of touch. In Comparative Example 1, the feeling and touch were not satisfactory because the polyester of the component A constituting the polyurethane composition of the present invention was not used. In Comparative Example 2, a large amount of the polyester of the component A in the polyurethane composition of the present invention was blended and applied to a leather-like sheet. This was sticky and could not be used substantially. In Comparative Examples 3 to 6, leather-like sheets were produced using a polyurethane composition other than the polyester having the specific structure of the present invention. These had poor jungle test durability or bad feeling. The touch was also poor. In Comparative Example 7, although the polyester having the specific structure of the present invention was used as the component A in the polyurethane composition, the resulting leather-like sheet was sticky because of its large molecular weight, and was practically used. It was impossible. In Comparative Example 8, a polyester-based polyurethane other than the polyurethane having the specific structure of the present invention was used as the B-component polyurethane in the polyurethane composition. The obtained leather-like sheet material was not satisfactory in jungle test durability and feeling. In Comparative Examples 9 and 10, the polyurethane of the B component in the polyurethane composition was applied to a leather-like sheet using a polyether-based polyurethane. The obtained leather-like sheet material had poor durability in a heat deterioration test, and yellowing was observed. In Comparative Example 11, a leather-like sheet was produced by using PPG instead of polyester in the component A in the polyurethane composition. The leather-like sheet obtained had a good touch, but had poor durability in the heat deterioration test and yellowing was observed. From these results, the leather-like sheet material to which the polyurethane composition of the present invention is applied has excellent feeling, cold resistance, touch, and the like, and also has excellent durability against a heat deterioration test, a jungle test, and the like. It turns out that it has.

[0027]

Industrial Applicability The polyurethane composition of the present invention can be applied to a leather-like sheet such as synthetic leather and artificial leather, and has excellent flexibility, feeling, touch, etc., and also has excellent heat deterioration and wet heat resistance. Can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-259957 (JP, A) JP-A-63-182330 (JP, A) JP-A-2-20514 (JP, A) JP-A-2-205 33384 (JP, A) JP-A-3-35053 (JP, A) JP-A-3-35055 (JP, A) JP-A-3-188121 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 75/00-75/16 C08G 18/00-18/87 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] 1. A. General formula (Wherein, m and n are positive integers, the sum of which is 4 or more and 8 or less ), and obtained by polycondensation with an aliphatic dicarboxylic acid or an ester-forming derivative thereof , 5 to 30% by weight of a polyester having a number average molecular weight of 700 to 5000; At least one alkanediol having 8 to 10 carbon atoms selected from the group consisting of 1,8-octanediol and 1,9-nonanediol which may be substituted with a methyl group, and an aliphatic dicarboxylic acid or its ester-forming property
A polyurethane composition comprising 70 to 95% by weight of a polyurethane obtained by reacting a polyester diol obtained by polycondensing a derivative with a diisocyanate and a chain extender.