JPH07149879A - Polyester elastomer and its production - Google Patents

Abstract

PURPOSE:To obtain a polyester elastomer having excellent durability such as heat-resistance and oxidation resistance and exhibiting especially excellent elastic recovery and hydrolysis resistance and, accordingly, widely usable in the field of fibers, films, resins, etc. CONSTITUTION:This polyester elastomer is composed of a polyester segment A and a polyester segment B bonded with each other through an ester bond. The polyester segment A is composed of (a-1) an acid component composed mainly of isophthalic acid and a branched saturated aliphatic dicarboxylic acid having a 1-4C alkyl group bonded as a side chain to a carbon atom of a 6-12C main chain, wherein the isophthalic acid accounts for 60-90 mol% of the total acid component and the branched saturated aliphatic dicarboxylic acid accounts for 10-40mol% of the total acid component and (a-2) a glycol component composed mainly of a 6-12C straight-chain saturated aliphatic alpha,omega-diol. The polyester segment B is composed of (b-1) an acid component composed mainly of an aromatic dicarboxylic acid and (b-2) a glycol component composed mainly of at least one kind of diol selected from a 2-4C straight-chain saturated aliphatic alpha,omega-diol and 1,4-cyclohexanedimethanol.

Description

Detailed Description of the Invention

[0001]

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

[0002]

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 as a so-called polyester elastomer for various purposes. That is.

Further, as a polyester elastomer having excellent heat resistance, weather resistance and chlorine resistance, isophthalic acid and / or phthalic acid is used as a main acid component, and the carbon number is 6 to 12
JP-A-4-33919 discloses the elasticity of polyester having a soft component of polyester having an aliphatic α, ω-diol as a main glycol component.

In order to improve the elastic recovery performance at low temperature, which is a drawback of the elastic body disclosed in the above publication, the soft segment polyester has 6 to 1 carbon atoms as an acid component.
The use of the long-chain aliphatic dicarboxylic acid of 2 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 above aliphatic dicarboxylic acid.

[0005]

According to the research conducted by the present inventors, the polyester elastic body disclosed in JP-A-5-32770 was certainly improved in elastic recovery performance at low temperatures. It was revealed that hydrolysis resistance was not sufficient. An object of the present invention is to provide a polyester elastic body capable of giving an elastic yarn excellent in elastic recovery performance and hydrolysis resistance even at a low temperature, and a method for producing the same.

[0006]

According to the present invention, a first
In addition, (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. , Where the isophthalic acid is 60 to 9 of the total acid component.
0% by mole, the branched saturated aliphatic dicarboxylic acid accounts for 10 to 40% by mole of all acid components, and (a-2) has 6 carbon atoms.
To a polyester moiety (A) containing a linear saturated aliphatic α, ω-diol as a main glycol component, and (b-
1) Aromatic dicarboxylic acid as a main acid component, (b-
2) A polyester moiety (B) having a glycol component of at least one diol selected from the group consisting of linear saturated aliphatic α, ω-diols having 1, 4 or 4 carbon atoms and 1,4-cyclohexanedimethanol. There is provided a polyester elastic body characterized by being bonded 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 1 to 100% of the total acid component.
0 to 40 mol%, (a-2) a polyester (A ′) containing a linear 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, (b-2) carbon number 2 to
Ester prepared by melt-mixing the linear saturated aliphatic α, ω-diol of 4 and a polyester (B ′) having a glycol component of at least one diol selected from the group consisting of 1,4-cyclohexanedimethanol. An exchange reaction is carried out, and the melting point is 2 to 4 from the melting point of the polyester (B ').
Provided is a method for producing a polyester elastic body, which comprises 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, and further objects, configurations, advantages and effects of the present invention will be apparent from the present invention.

The acid component of the polyester part (A) constituting the polyester elastomer of the present invention comprises isophthalic acid and a carbon atom of the main chain having 6 to 12 carbon atoms, and an alkyl group having 1 to 4 carbon atoms as a side chain. It is mainly composed of a branched saturated aliphatic dicarboxylic acid bonded thereto.

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

In the above aliphatic dicarboxylic acid, an alkyl group having 1 to 4 carbon atoms is bonded to at least one, preferably 2 to 4 alkyl group to a carbon atom of the main chain having 6 to 12 carbon atoms. Specific examples of preferable 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 at least one of the carbon atoms adjacent to the carbon atom, and the alkyl group may be bonded to any carbon atom. More preferable.

As preferred specific examples of the above aliphatic dicarboxylic acid, 2,5-dimethyladipic acid, 3,4-dimethyladipic acid, 2,2,4-trimethyladipic acid, 2,4, and
4-trimethyl adipic acid etc. can be illustrated.

By using such a branched saturated aliphatic dicarboxylic acid together with isophthalic acid as the acid component of the polyester part (A), the polyester elastic body of the present invention has an excellent elastic recovery rate in a low temperature atmosphere and is resistant to Excellent in hydrolyzability.

The proportion of isophthalic acid in the total acid component of the polyester part (A) is 60 to 90 mol%, preferably 60 to 80 mol%. Similarly, the proportion of the branched saturated aliphatic dicarboxylic acid is 10 to 40 mol%.
And preferably 20 to 40 mol%. The polyester part (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 component of the polyester part (A). It is preferable that it is 5 mol% or less, and it is particularly preferable.

The main glycol component constituting the polyester portion (A) is a linear saturated aliphatic α having 6 to 12 carbon atoms,
It is an omega-diol. This diol can be represented by the following formula (1) when expressed by a chemical formula. _{HO- (CH 2) n -OH ───} (1) ( where n is an integer from 6-12) glycol component of aliphatic such long chain alpha, .omega. diol polyester portion (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. It can be illustrated. These may be used alone or in combination of two or more.

When the proportion of the branched saturated aliphatic dicarboxylic acid described above in the acid component of the polyester portion (A) is X mol%, the following mathematical formula (1) 120 / m ≦ X ≦ 40 --- Numerical formula (1) (It is more preferable that m is the average carbon number 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 performance of the polyester elastic body is good even if the proportion of the branched saturated aliphatic dicarboxylic acid component is relatively small. Means that it can be maintained.

The polyester part (A) may contain, as a glycol component, a glycol component other than the above-mentioned linear saturated aliphatic α, ω-diol, the amount of which is the total glycol component of the polyester part (A). It is preferably 20 mol% or less, and particularly preferably 10 mol% or less.

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

The polyester part (B) is a glycol component mainly 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. And Examples of the above aliphatic α, ω-diols include ethylene glycol, trimethylene glycol and tetramethylene glycol.

The polyester part (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). % Or less, particularly preferably 10 mol% or less.

Preferred representative examples of the polyester moiety (B) are poly (tetramethylene terephthalate) segment, poly (tetramethylene-2,6-naphthalene dicarboxylate) segment and poly (1,4-cyclohexane dimethylene terephthalate) segment. Can be mentioned. The polyester elastic body having these segments as the polyester portion (B) has good crystallinity and a high crystallization rate.

In the polyester elastic material of the present invention, the above-mentioned polyester portion (A) and polyester portion (B) are bonded via an ester bond. The weight ratio of the polyester portion (A) to the polyester portion (B) is preferably 90:10 to 30:70 from the viewpoint of giving the polyester elastic body of the present invention elastic recovery performance. When the above 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 has 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 elastic body 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) as a suitable catalyst. It can be easily obtained by melt-mixing in the presence of the above and carrying out an ester exchange reaction (redistribution reaction).

At this time, 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 Is preferably 0.6 to 1.2 dl / g.

The degree of progress of the transesterification reaction changes depending on the reaction conditions such as temperature, reaction time and stirring speed adopted in the transesterification reaction carried out under the above-mentioned melt-mixing, and the product obtained as a result changes accordingly. The physical properties of the polyester elastic body change. The composition of the raw materials polyester (A ') and polyester (B'), the molecular weight, the type of reactor used, the type of catalyst, and the like influence the transesterification reaction. Therefore, it is difficult to unambiguously describe the relationship between the physical properties of the obtained polyester elastomer and the reaction conditions and other factors affecting 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 reaction conditions and other factors affecting the transesterification reaction are known experimentally in advance. Therefore, it is easy to produce a polyester elastomer having the intended physical properties.

Generally, the temperature for melt mixing is 240 to
It is 280 ° C. and the reaction time is 5 to 60. Under such conditions, the polymer hardly decomposes. A titanium catalyst or a tin catalyst is used as the catalyst.

In the transesterification reaction, the melting point of the obtained polyester elastic body is 2 to 40 ° C. higher than the melting point of the polyester (B ′) which is more crystalline than the polyester (A ′),
It is particularly preferable to carry out the treatment 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 polyester (A ′) and polyester (B ′), and the transesterification reaction proceeds excessively to form a random copolymer. It can be avoided that the product becomes an elastic body having appropriate elastic recovery performance.

It is not always necessary to immediately mold the polyester elastic body after the transesterification reaction. However, for example, when the polyester elastic body is once made into chips and then melted and molded again, the transesterification reaction further progresses at the time of remelting. Then, since the properties of the block copolymer change, it is desirable to stop the transesterification reaction before forming into chips. As a method of stopping this reaction, a method of deactivating the catalytic ability is generally used. For example, when a titanium or tin catalyst is used as a transesterification reaction catalyst, phosphoric acid, phosphorous acid,
A method of adding a phosphonic acid, phosphinic acid or a derivative thereof to deactivate the catalytic ability can be adopted.

In the above-mentioned method of deactivating the catalytic ability, the catalytic activity is not completely stopped at a temperature of 260 ° C. or higher, and the deactivating effect by 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 the reaction and molding can be performed at a low temperature.

The polyester elastomer of the present invention contains a branching agent, a sulfonate compound for imparting cationic dyeability, a phosphorus compound for imparting flame retardancy, and a small amount of other copolymerization components, preferably May be copolymerized in the range of 10% by weight or less. Further, pigments, dyes, fillers, flame retardants, stabilizers and the like may be contained.

[0035]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the examples, "part" means part 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
Parts (30 mol%) and 142 parts of 1,6-hexanediol, 0.14 parts of titanium tetrabutoxide (0.04 mol% based on the total amount of dimethyl isophthalate and 2,4,4-trimethyladipic acid). ) As a catalyst,
After esterification reaction and esterification reaction to distill off methanol and water, polycondensation is carried out by a conventional method under high vacuum to obtain polyester I-1 having an intrinsic viscosity of 0.90 dl / g.
Got

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

Next, 70 parts of polyester I-1 was added to 30 parts of polyester II-1 and stirred at 250 ° C. under a high vacuum of 1 mmHg or less to carry out a transesterification reaction using the above-mentioned titanium tetrabutoxide as a catalyst. Twenty minutes after the contents became transparent, phenylphosphonic acid was added to 0.
The reaction was stopped by adding 05 parts and further stirring for 10 minutes. The intrinsic viscosity of the obtained polyester elastic body is 0.95.
It was dl / g and the melting point was 210 ° C. The melting point was measured by a differential scanning calorimeter (DSC) at a temperature rising rate of 20 ° C./minute to obtain an endothermic peak temperature.

This polyester elastic body is heated at 250 ° C. for 12 hours.
It was discharged from the die of the hole and wound at a speed of 400 m / min to obtain an elastic yarn. This elastic thread has a strength of 0.8 g / d
e, the elongation was 560%. This yarn at 200 at 200
The elastic recovery as measured by immediate recovery after a% elongation (3 times the original length) was 85%. Further, when the same elastic recovery rate was measured in ice water, the elastic recovery rate was 78%. Further, the hydrolysis resistance was good such that the strength retention rate after standing for 1 hour in pressurized water of 130 ° C. was 71%.

[0040]

Comparative Examples 1 and 2 and Examples 2 and 3 The dicarboxylic acids, diesters of dicarboxylic acids and diols listed in Table 1 were used in the proportions listed in Table 1, and titanium tetrabutoxide was used as a catalyst in the dicarboxylic acid and dicarboxylic acid. The esterification reaction, the transesterification reaction, and the 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 to carry out polyester I-2 (Comparative Example 1) and polyester I-3 Comparative Example 2), Polyester I-4 (Example 2) and Polyester I-5 (Example 3) were prepared.

Polyester I of each of these and Example 1
Using the polyester II-1 prepared in 1. in the proportions shown in Table 2, the same operation as in Example 1 was carried out to carry out the transesterification reaction under melt mixing. The time when the contents became transparent varied depending on each example, but at that time, phenylphosphonic acid was added to deactivate the catalyst to stop the reaction and obtain a polyester elastic body.

The physical properties of the obtained polyester elastic body were measured in the same manner as in Example 1, and the elastic yarn was prepared and its physical properties were measured in the same manner as in Example 1. The results are shown in Table 3.
The symbols in the table are as follows. DMI: dimethyl isophthalate DMA: dimethyl adipate AZA: azelaic acid 2,4,4-TMA: 2,4,4-trimethyl adipic 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,
Since it has excellent durability such as oxidation resistance, and particularly excellent elastic recovery performance and hydrolysis resistance, it can be applied to a wide range of applications such as fibers, films and resins.

Claims (4)

[Claims] 1. (a-1) Isophthalic acid and 6 carbon atoms
The main acid component is a branched saturated aliphatic dicarboxylic acid in which an alkyl group having 1 to 4 carbon atoms is bonded as a side chain to the carbon atom of the main chain of -12, and the isophthalic acid is 60 to 60% of the total acid component. 90 mol%, the branched saturated aliphatic dicarboxylic acid is 10 to 40 mol% of the total acid component, (a-
2) A polyester moiety (A) containing a linear 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, and (b- 2) Polyester part (B) containing at least one diol selected from the group consisting of linear saturated aliphatic α, ω-diols and 1,4-cyclohexanedimethanol having 2 to 4 carbon atoms as a main glycol component. A polyester elastic body characterized in that and are bonded via an ester bond. 2. The weight ratio of the polyester part (A) to the polyester part (B) is 90:10 to 30:70,
The polyester elastic body according to claim 1, wherein the intrinsic viscosity of the polyester elastic body measured in an orthochlorophenol solvent at 35 ° C. is 0.4 to 2.0 dl / g. 3. (a-1) Isophthalic acid and 6 carbon atoms
The main acid component is a branched saturated aliphatic dicarboxylic acid in which an alkyl group having 1 to 4 carbon atoms is bonded as a side chain to the carbon atom of the main chain of -12, and the isophthalic acid is 60 to 60% of the total acid component. 90 mol%, the branched saturated aliphatic dicarboxylic acid is 10 to 40 mol% of the total acid component, (a-
2) Polyester (A ') having 6 to 12 carbon atoms as a main glycol component of a linear saturated aliphatic α, ω-diol
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.
-A diol and a polyester (B ') containing at least one diol selected from the group consisting of 1,4-cyclohexanedimethanol as a glycol component are melt-mixed to perform an ester exchange reaction, and the melting point of the polyester (B') is A method for producing a polyester elastic body, which comprises obtaining a reaction product having a melting point of 2) to 40 ° C. lower than the melting point thereof. 4. The method for producing a polyester elastic body 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.