JP3251746B2 - Polyester elastic body and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyester elastomer and a method for producing the same. More specifically, the present invention relates to a polyester elastic body which is excellent in durability such as weather resistance and heat resistance, and is suitable for obtaining an elastic yarn having excellent elastic recovery performance and hydrolysis resistance, and a method for producing the same.

[0002]

2. Description of the Related Art It is well known that a polyester block copolymer having an aromatic polyester as a hard segment and an aliphatic polyether or an aliphatic polyester as a soft segment is used for various applications as a so-called polyester elastic body. That is.

[0003] Further, as a polyester elastic material having excellent heat resistance, weather resistance and chlorine resistance, isophthalic acid and / or phthalic acid is used as a main acid component and contains 6 to 12 carbon atoms.
Japanese Patent Application Laid-Open No. 4-33919 discloses a polyester elasticity using a polyester having an aliphatic α, ω-diol as a main glycol component as a soft component.

In order to improve the elastic recovery performance at a low temperature, which is a drawback of the elastic body disclosed in the above publication, the acid component of the soft segment polyester has 6 to 1 carbon atoms.
The use of two long-chain aliphatic dicarboxylic acids together with isophthalic acid and / or phthalic acid is disclosed in JP-A-5-32770. However, this publication does not disclose or suggest the use of a branched aliphatic carboxylic acid as the aliphatic dicarboxylic acid.

[0005]

According to the study of the present inventors, the polyester elastic body disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-32770 has certainly improved the elastic recovery performance at low temperatures. In addition, it became clear that the hydrolysis resistance was not sufficient. An object of the present invention is to provide a polyester elastic body which can provide an elastic yarn having excellent elastic recovery performance even at a low temperature and excellent hydrolysis resistance, and a method for producing the same.

[0006]

According to the present invention, there is provided:
(A-1) isophthalic acid and a branched saturated aliphatic dicarboxylic acid in which an alkyl group having 1 to 4 carbon atoms is bonded as a side chain to a carbon atom of a main chain having 6 to 12 carbon atoms as a main acid component; Wherein the isophthalic acid is 60-9 of the total acid component
0 mol%, and the branched saturated aliphatic dicarboxylic acid accounts for 10 to 40 mol% of the total acid component, and (a-2) has 6 carbon atoms.
And a polyester moiety (A) having a linear saturated aliphatic α, ω-diol of from 1 to 12 as a main glycol component;
1) An aromatic dicarboxylic acid is used as a main acid component, and (b-
2) a polyester moiety (B) having at least one diol selected from the group consisting of linear saturated aliphatic α, ω-diols having 2 to 4 carbon atoms and 1,4-cyclohexanedimethanol as a glycol component; Are connected via an ester bond.

Further, according to the present invention, secondly, (a-
1) isophthalic acid and a branched saturated aliphatic dicarboxylic acid in which an alkyl group having 1 to 4 carbon atoms is bonded as a side chain to a carbon atom of a main chain having 6 to 12 carbon atoms as a main acid component;
Here, the isophthalic acid is 60 to 90 mol% of the total acid component, and the branched saturated aliphatic dicarboxylic acid is one of the total acid component.
0 to 40 mol%, (a-2) a polyester (A ′) containing a straight-chain saturated aliphatic α, ω-diol having 6 to 12 carbon atoms as a main glycol component, and (b-1) an aromatic compound Dicarboxylic acid as a main acid component, (b-2) having 2 to 2 carbon atoms
And polyester (B ') containing at least one diol selected from the group consisting of linear saturated aliphatic α, ω-diol and 1,4-cyclohexanedimethanol as a glycol component by melt-mixing with polyester (B ′). An exchange reaction is performed, and the melting point is 2 to 4 from the melting point of the polyester (B ').
There is provided a method for producing a polyester elastomer, characterized by obtaining a reaction product at 0 ° C. lower.

The above objects of the present invention are achieved by these inventions. Hereinafter, the present invention will be described in detail, from which further objects, configurations, advantages, and effects of the present invention will become apparent.

The acid component of the polyester part (A) constituting the polyester elastic body of the present invention includes isophthalic acid and a carbon atom of a main chain having 6 to 12 carbon atoms, and an alkyl group having 1 to 4 carbon atoms as a side chain. It is predominantly composed of linked branched saturated aliphatic dicarboxylic acids.

The main chain of the branched saturated aliphatic dicarboxylic acid refers to a straight chain having a carboxyl group at both ends, and the number of carbon atoms thereof is the number including the carbon atoms of the carboxyl group.

In the aliphatic dicarboxylic acid, at least one, preferably two to four alkyl groups having 1 to 4 carbon atoms are bonded to carbon atoms of the main chain having 6 to 12 carbon atoms. Specific examples of preferred alkyl groups include a methyl group and an isopropyl group. The alkyl group is preferably bonded to a carbon atom adjacent to the carbon atom of the carboxyl group and further to at least any one of the carbon atoms next to the carbon atom, and the alkyl group is preferably bonded to any of the carbon atoms. Is more preferred.

Preferred specific examples of the aliphatic dicarboxylic acid include 2,5-dimethyladipic acid, 3,4-dimethyladipic acid, 2,2,4-trimethyladipic acid, 2,4,
Examples thereof include 4-trimethyladipic acid.

By using such a branched saturated aliphatic dicarboxylic acid together with isophthalic acid as the acid component of the polyester portion (A), the polyester elastomer of the present invention has an excellent elastic recovery rate in a low-temperature atmosphere and has a high durability. Excellent hydrolytic properties.

The proportion of isophthalic acid in the total acid component of the polyester portion (A) is 60 to 90 mol%, preferably 60 to 80 mol%. Similarly, the proportion occupied by the branched saturated aliphatic dicarboxylic acid is 10 to 40 mol%.
And preferably 20 to 40 mol%. The polyester portion (A) can contain an acid component other than isophthalic acid and a branched saturated aliphatic dicarboxylic acid as an acid component, but the amount thereof is 10 mol% or less of the total acid components of the polyester portion (A). It is particularly preferable that the content be 5 mol% or less.

The main glycol component constituting the polyester portion (A) is a linear saturated aliphatic α, having 6 to 12 carbon atoms.
ω-diol. This diol can be represented by the following formula (1) when represented by a chemical formula. HO- (CH ₂ ) _n -OH─── (1) (where n is an integer of 6 to 12) Such a long-chain aliphatic α, ω-diol is used as a glycol component of the polyester moiety (A). As a result, the elastic recovery performance of the polyester elastic body of the present invention is excellent.

Specific examples of the linear saturated aliphatic α, ω-diol include 1,4-hexanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,9-nonanediol. Examples can be given. These may be used alone or in combination of two or more.

When the ratio of the branched saturated aliphatic dicarboxylic acid in the polyester component (A) in the acid component is X mol%, the following formula (1): 120 / m ≦ X ≦ 40 (Where m is more preferably the average number of carbon atoms of the linear saturated aliphatic α, ω-diol). By satisfying the above formula, the low-temperature elastic recovery performance of the polyester elastic body of the present invention is maintained at a high level. This means that when the chain length of the α, ω-diol is long (when the number of carbon atoms is large), the above-mentioned performance of the polyester elastomer is excellent even when the proportion of the branched saturated aliphatic dicarboxylic acid component is relatively small. It can be maintained.

The polyester portion (A) may contain, as a glycol component, a glycol component other than the above-mentioned linear saturated aliphatic α, ω-diol, but the amount thereof is the same as the total glycol component of the polyester portion (A). It is preferably at most 20 mol%, particularly preferably at most 10 mol%.

The polyester portion (B) constituting the polyester elastomer of the present invention contains an aromatic dicarboxylic acid as a main acid component. Specific examples of the aromatic dicarboxylic acid include terephthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4′-
Examples thereof include diphenyldicarboxylic acid.

The polyester portion (B) may contain an acid component other than the aromatic dicarboxylic acid as the acid component, but the amount thereof is 20% of the total acid component of the polyester portion (B).
It is preferably at most 10 mol%, particularly preferably at most 10 mol%.

The polyester moiety (B) comprises at least one diol selected from the group consisting of linear saturated aliphatic α, ω-diols having 2 to 4 carbon atoms and 1,4-cyclohexanedimethanol, and a glycol component as a main component. And Examples of the aliphatic α, ω-diol include ethylene glycol, trimethylene glycol and tetramethylene glycol.

The polyester portion (B) may contain a glycol component other than the above-mentioned linear saturated aliphatic α, ω-diol as a glycol component, but the amount thereof is 20 mol of the total glycol component of the polyester (B). %, Particularly preferably 10 mol% or less.

Preferred representative examples of the polyester moiety (B) include a poly (tetramethylene terephthalate) segment, a poly (tetramethylene-2,6-naphthalenedicarboxylate) segment and a poly (1,4-cyclohexanedimethylene terephthalate) segment. Can be mentioned. The polyester elastomer having these segments as the polyester portion (B) has good crystallinity and a high crystallization rate.

In the polyester elastic body of the present invention, the above-mentioned polyester portion (A) and polyester portion (B) are connected via an ester bond. The weight ratio of the polyester portion (A) to the polyester portion (B) is preferably from 90:10 to 30:70 from the viewpoint of providing the polyester elastic body of the present invention with elastic recovery performance. When the ratio is in the range of 80:20 to 50:50, a polyester elastic body having more excellent rubber elasticity can be obtained.

The polyester elastomer of the present invention may have an intrinsic viscosity of 0.4 to 2.0 dl / g, particularly 0.6 to 1.5 dl / g, measured at 35 ° C. in an orthochlorophenol solvent. preferable.

The polyester elastomer of the present invention described in detail above comprises, for example, a polyester (A ') having the same composition as the polyester portion (A) and a polyester (B') having the same composition as the polyester portion (B). Can be easily obtained by performing a transesterification reaction (redistribution reaction) by melt-mixing in the presence of.

In this case, the intrinsic viscosity of the polyester (A ′) (measured in an orthochlorophenol solvent at 35 ° C.) is preferably 0.6 to 1.5 dl / g, and the intrinsic viscosity of the polyester (B ′) Is preferably 0.6 to 1.2 dl / g.

The degree of progress of the transesterification reaction varies depending on reaction conditions such as temperature, reaction time, stirring speed and the like employed in the transesterification reaction carried out under the above-mentioned melt mixing. The physical properties of the polyester elastic body change. The composition and molecular weight of the raw material polyesters (A ′) and polyesters (B ′), as well as the type of reactor and catalyst used, affect the transesterification reaction. Therefore, it is difficult to clearly describe the relationship between the physical properties of the obtained polyester elastic material, the reaction conditions, and other factors that affect the transesterification reaction.

However, once the composition and molecular weight of the polyester (A ') and the polyester (B'), and the reaction apparatus are determined, the relationship between the reaction conditions affecting the transesterification reaction and other factors is experimentally known in advance. Therefore, it is easy to produce a polyester elastic body having intended properties.

Generally, the temperature for melting and mixing is 240 to
280 ° C and the reaction time is 5-60. Under such conditions, little degradation of the polymer occurs. As the catalyst, a titanium catalyst or a tin catalyst is used.

In the transesterification reaction, the melting point of the obtained polyester elastomer is 2 to 40 ° C. lower than the melting point of the polyester (B ′) which is more crystalline than the polyester (A ′).
In particular, it is preferable to perform the process until the temperature is lowered by 5 to 30 ° C. By doing so, it is possible to avoid that the obtained product is simply a mixture of the polyester (A ′) and the polyester (B ′), and the transesterification reaction proceeds excessively to form a random copolymer. This can be avoided, and the product becomes an elastic body having appropriate elastic recovery performance.

Although it is not always necessary to immediately mold the polyester elastic body after the transesterification reaction, for example, when it is formed into chips and then melted and molded again, the transesterification reaction further proceeds during remelting. As a result, the properties of the block copolymer change, so that it is desirable to stop the transesterification reaction before forming the chips. As a method for stopping this reaction, a method for deactivating the catalytic activity is generally used.For example, when a titanium or tin catalyst is used as a transesterification catalyst, phosphoric acid, phosphorous acid,
A method of adding phosphonic acid, phosphinic acid or a derivative thereof to deactivate the catalytic ability can be employed.

In the above-described method for deactivating the catalytic activity, when the temperature exceeds 260 ° C., the catalytic activity is not completely stopped and the deactivating effect of the method is reduced. When the melting point exceeds 260 ° C., it is desirable to use a solvent, a plasticizer, or the like in advance so that reaction and molding at a low temperature can be performed.

The polyester elastomer of the present invention contains a small amount of a branching agent, a sulfonate compound for imparting cationic dyeability, a phosphorus compound for imparting flame retardancy, and other copolymer components. May be copolymerized in a range of 10% by weight or less. Further, a pigment, a dye, a filler, a flame retardant, a stabilizer and the like may be contained.

[0035]

The present invention will be described in more detail with reference to the following examples. In the examples, "parts" indicates parts by weight, and the intrinsic viscosity is measured in orthochlorophenol at 35 ° C.

[0036]

Example 1 135.8 parts of dimethyl isophthalate (7
0 mol%) 2,4,4-trimethyladipic acid 56.4
Part (30 mol%) and 142 parts of 1,6-hexanediol were combined with 0.14 part of titanium tetrabutoxide (0.04 mol% based on the total amount of dimethyl isophthalate and 2,4,4-trimethyl adipic acid). ) As a catalyst,
After methanol and water are distilled off by a transesterification reaction and an esterification reaction, the polyester I-1 having an intrinsic viscosity of 0.90 dl / g is subjected to polycondensation by a conventional method under a high vacuum.
I got

On the other hand, 194 parts of dimethyl terephthalate and 180 parts of tetramethylene glycol were subjected to transesterification in the same manner as described above using 0.1 part of titanium tetrabutoxide (30 mmol% based on dimethyl terephthalate) as a catalyst. Polycondensation, intrinsic viscosity of 0.
Polyester II-1 having a melting point of 225 ° C. was obtained at 92 dl / g.

Next, 70 parts of the polyester I-1 was added to 30 parts of the polyester II-1, and the mixture was stirred at 250 ° C. under a high vacuum of 1 mmHg or less, and transesterification was carried out using titanium tetrabutoxide as a catalyst. Twenty minutes after the contents became clear, phenylphosphonic acid was added to 0.1 ml.
The reaction was stopped by adding 05 parts and stirring for further 10 minutes. The intrinsic viscosity of the obtained polyester elastomer is 0.95.
dl / g and the melting point was 210 ° C. The melting point was measured by a differential scanning calorimeter (DSC) at a heating rate of 20 ° C./min to determine an endothermic peak temperature.

This polyester elastic material was cured at 250 ° C. for 12 hours.
It was discharged from the base of the hole and wound up at a speed of 400 m / min to obtain an elastic yarn. This elastic yarn has a strength of 0.8 g / d.
e, elongation was 560%. This yarn is 200
Immediately after the% elongation (three times the original length), the elastic recovery was 85% as measured by recovery. When the same elastic recovery was measured in ice water, the elastic recovery was 78%. The hydrolysis resistance was as good as 71% of the strength retention after leaving for 1 hour in pressurized water at 130 ° C.

[0040]

Comparative Examples 1 and 2 and Examples 2 and 3 Dicarboxylic acids, diesters of dicarboxylic acids and diols shown in Table 1 were used in the proportions shown in Table 1, and titanium tetrabutoxide was used as a catalyst with dicarboxylic acid and dicarboxylic acid. An esterification reaction, a transesterification reaction and a polycondensation were carried out in the same manner as in Example 1 using 0.04 mol% with respect to the total amount of the acid ester, and polyester I-2 (Comparative Example 1), polyester I-3 ( Comparative Example 2), Polyester I-4 (Example 2) and Polyester I-5 (Example 3) were prepared.

Each of these polyesters I and Example 1
Using the polyester II-1 prepared in the above at a ratio shown in Table 2, the same operation as in Example 1 was performed to carry out a transesterification reaction under melt mixing. The point in time at which the contents became transparent varies depending on the case. At that point, phenylphosphonic acid was added to deactivate the catalyst, thereby terminating the reaction and obtaining a polyester elastomer.

The physical properties of the obtained polyester elastomer were measured in the same manner as in Example 1, and the preparation of the elastic yarn and the measurement of the physical properties were performed in the same manner as in Example 1. Table 3 shows the results.
The symbols in the table are as follows. DMI: dimethyl isophthalate DMA: dimethyl adipate AZA: azelaic acid 2,4,4-TMA: 2,4,4-trimethyladipic acid 1,6-HD: 1,6-hexanediol

[0043]

[Table 1]

[0044]

[Table 2]

[0045]

[Table 3]

[0046]

The polyester elastic body of the present invention has heat resistance,
It is excellent in durability such as oxidation resistance, and particularly excellent in elastic recovery performance and hydrolysis resistance, so that it can be applied to a wide range of applications such as fibers, films and resins.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (4)

(57) [Claims] 1. (a-1) isophthalic acid and carbon number 6
A branched saturated aliphatic dicarboxylic acid in which an alkyl group having 1 to 4 carbon atoms is bonded as a side chain to a carbon atom of a main chain of 12 to 12 as a main acid component, wherein the isophthalic acid is 60 to 90 mol%, and the branched saturated aliphatic dicarboxylic acid accounts for 10 to 40 mol% of the total acid component;
2) A polyester moiety (A) having a straight-chain saturated aliphatic α, ω-diol having 6 to 12 carbon atoms as a main glycol component, and (b-1) an aromatic dicarboxylic acid as a main acid component, wherein (b- 2) Polyester portion (B) containing at least one diol selected from the group consisting of linear saturated aliphatic α, ω-diols having 2 to 4 carbon atoms and 1,4-cyclohexanedimethanol as a main glycol component. Are bonded through an ester bond. 2. The weight ratio of the polyester part (A) to the polyester part (B) is from 90:10 to 30:70,
The polyester elastic body according to claim 1, wherein the intrinsic viscosity of the polyester elastic body measured at 35 ° C in an orthochlorophenol solvent is 0.4 to 2.0 dl / g. 3. (a-1) isophthalic acid and carbon number 6
A branched saturated aliphatic dicarboxylic acid in which an alkyl group having 1 to 4 carbon atoms is bonded as a side chain to a carbon atom of a main chain of 12 to 12 as a main acid component, wherein the isophthalic acid is 60 to 90 mol%, and the branched saturated aliphatic dicarboxylic acid accounts for 10 to 40 mol% of the total acid component;
2) Polyester containing linear saturated aliphatic α, ω-diol having 6 to 12 carbon atoms as a main glycol component (A ′)
And (b-1) an aromatic dicarboxylic acid as a main acid component, and (b-2) a linear saturated aliphatic α, ω having 2 to 4 carbon atoms.
And a polyester (B ′) containing at least one diol selected from the group consisting of -diol and 1,4-cyclohexanedimethanol as a glycol component, and the mixture is subjected to a transesterification reaction. A method for producing a polyester elastomer, characterized by obtaining a reaction product 2 to 40 ° C. lower than the melting point of (1). 4. The process for producing a polyester elastomer according to claim 3, wherein the mixing ratio of the polyester (A ′) to the polyester (B ′) is a polymerization ratio of 90:10 to 30:70.