KR0150691B1 - Process for preparing polyester block copolymer - Google Patents

Abstract

The present invention is a compound of the following general formula 1 that can cause crosslinking in the production of a polyetherester block copolymer comprising a polybutylene terephthalate polyester as a hard segment and a polyoxybutylene glycol polyester as a soft segment. 1,2,4,5-Benzenetetracarboxylic dianhydride derivatives

Durability characterized by copolymerization at 0.05 to 0.7 mol% with respect to dimethyl terephthalate and addition of stearic acid metal salt as a nucleating agent at 0.05 to 3% by weight with respect to the polymer, followed by condensation polymerization reaction after esterification or transesterification in a conventional manner. And it relates to a method for producing a polyether ester block copolymer with improved elastic properties.

Description

Method for producing polyether ester block copolymer

The present invention relates to a method for producing a polyether ester block copolymer having excellent elasticity and durability, and more specifically, polybutylene terephthalate-based polyester as a hard segment and polyoxy butylene glycol-based polyether as a soft segment. Derivation of 1,2,4,5-benzenetetracarboxylic dianhydride (1,2,4,5-Benzenetetracarboxylic dianhydride) of the following general formula as a crosslinking agent in the preparation of the polyetherester block copolymer

Sieve is copolymerized at 0.05 to 0.7% with respect to dimethyl terephthalate, and the stearic acid metal salt is added at 0.05 to 3% by weight with respect to the polymer as a nucleating agent to perform condensation polymerization after esterification or transesterification in a conventional manner. It relates to a method for producing a polyether ester block copolymer having improved durability and elastic properties.

Conventional elastic yarns are used, such as rubber and polyturethane, but these materials exhibit excellent characteristics in terms of elastic recovery rate, but have problems in durability, such as heat resistance and weather resistance.

On the other hand, an elastomer in the form of a polyether ester block copolymer is used for resin, and this block copolymer is a copolymer in which polyether soft segments and polyester hard segments are irregularly arranged in a molecular chain, and thus have excellent elastic properties. It is used in industrial parts, sports goods, etc., where elastic performance is required, and in recent years, the amount of use thereof has been expanded in elastic clothes.

When the polymer is made of fibers, the elastic recovery rate is less than that of the polyurethane-based elastic yarn, but it has the advantage of showing good melt recovery performance and melt spinning under low elongation.

However, polyurethane-based elastic yarns are connected by chemical bonds called hydrogen bonds to form a very strong and difficult-to-break molecular structure.However, unlike polyurethane-based elastic yarns, elastic yarns are formed by crystallization of hard segments. Since chains are connected, the permanent mold is large and elastic performance is deteriorated.

In particular, when the elastic yarn in the form of polyether ester block copolymer is used as part or the whole of the knitted fabric, there is a problem of durability that is poor in elastic performance during post-treatment thereof. Therefore, in this respect, there is a demand for improvement of elastic performance, in particular, development of elastic yarns that are durable against dry heat treatment and wet heat treatment.

As a method of improving the performance of elastic yarns by improving such disadvantages, a method of increasing the degree of crystallinity using a crystal nucleating agent (Japanese Patent Laid-Open Nos. 59-45349 and 59-45350) has been proposed. However, such a method is not sufficient to be used as an elastic yarn because the performance of the elastic yarn cannot be greatly improved. In addition, a method of improving the elastic properties by improving the crystallinity of hard segments by blending a high melting point polybutylene terephthalate (Japanese Patent Application Laid-Open No. 58-141236) has been proposed. However, the lack of cohesion of crystals improves the elastic properties. Since it is not large, it is insufficient to be used as an elastic yarn. In addition, a method of increasing the elastic recovery rate by combining the crystalline polypropylene with the initial elastic modulus by lowering the elastic modulus has been proposed (Japanese Patent Application Laid-Open No. 57-56513). Do.

Accordingly, it is an object of the present invention to provide a method for producing an elastomeric polyetherester block copolymer having excellent elastic performance and durability.

In order to achieve the above object as well as another easily expressed object, in the present invention, in the preparation of a block copolymer in which the polyether soft segment and the polyester hard segment are irregularly arranged, when a specific crosslinking agent is introduced and stretched Resilience was maintained, and the addition of nucleating agents increased durability.

That is, the present inventors have studied to solve the problem of durability deterioration in elastic performance in post-treatment processes such as dry heat treatment and wet heat treatment when the polyether ester block copolymer elastomer has a large permanent deformation and a high content of soft segments. As a result, a specific crosslinking was introduced into the polyether ester block copolymer to form a crosslinking point that can maintain the recovery ability during elongation, and to prevent a decrease in the degree of crystallization accompanying the crosslinking introduction and thus a decrease in elastic performance. The crystal nucleating agent was added to improve the degree of crystallinity and the present invention was found to be able to obtain a polymer for elastic yarn production having improved elastic performance and durability in which the crystal structure is not easily broken by external force.

The present invention is described in more detail as follows.

In the present invention, 1,2,4,5-benzene of the following general formula when preparing a polyetherester block copolymer comprising a polybutylene terephthalate polyester as a hard segment and a polyoxybutylene glycol polyether as a soft segment Tetracarboxylic dianhydride (1,2,4,5-Benzenetetracarboxylic dianhydride) derivatives

Copolymer is 0.05 ~ 0.7 mol% to dimethyl terephthalate, and the stearic acid metal salt is mixed with 0.05 to 3% by weight with respect to the polymer as a nucleating agent, polycondensation reaction by polycondensation reaction after esterification or transesterification by conventional methods The coalescence was prepared.

In the present invention, tetramethylene glycol, a dimethyl terephthalate o aliphatic alkylene glycol, which is an aromatic dicarboxylic acid, was used as a component constituting the hard segment. In addition, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, Dicarboxylic acids such as 2,7-naphthalenedicarboxylic acid, bis (para-carboxyphenyl) methane and ester-forming derivatives thereof as dicarboxylic acid components, echelylene glycol, 1,3-propanediol, 1.5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, and the like can be used as the low molecular weight glycol component, and the amount of dicarboxylic acid or ester-forming derivative thereof other than dimethyl terephthalate is used. It is preferable to set it as 10 mol% or less.

As the soft segment, polytetramethylene glycol having a number average molecular weight of 1500 to 3000 was used. In addition, high molecular weight glycol components of polyethylene glycol and polypropylene glycol may be used. If the number average molecular weight of the polytetramethylene glycol is less than 1500, the blockability of the resulting polyether ester block copolymer is lowered, so that the elastic performance becomes poor, which is not preferable. If the molecular weight of the polytetramethylene glycol exceeds 3000, it is produced. It is not preferable because phase separation of the polymer is difficult to turn into a blow copolymer and the melting point of the polymer is low, resulting in problems of durability for dry heat treatment and wet heat treatment.

The amount of the 1,2,4,5-benzenetetracarboxylic dianhydride derivative used as the crosslinking agent in the polyether ester block copolymer is preferably 0.05 to 0.7 mol% with respect to dimethyl terephthalate, and the amount of addition is 0.05. If it is less than mol%, the crosslinking density is low, and thus, the desired elastic properties and durability cannot be expected. If it exceeds 0.7 mol%, the added 1,2,4,5-benzenetetracarboxylic dianhydride does not completely react. The flowability of the obtained polymer is poor, and when made into a fiber, shortage of elongation occurs, which is undesirable.

In addition, the stearic acid metal salt, which is a crystallization agent, is added in an amount of 0.05 to 3% by weight. When the amount is less than 0.05% by weight, the effect of promoting crystallization is small. It is difficult to produce a polymer having a desired degree of polymerization, and when it is made of fibers, there arises a problem that the physical properties of the elastic body are lowered due to uneven physical properties.

In general, the content of polytetramethylene glycol in the polyether ester block copolymer is in the range of 65 to 75% by weight, and when it exceeds 75% by weight, the elastic performance is excellent while the melting point of the copolymer is low, resulting in dry heat and In the wet heat treatment, the elasticity is poor, the elastic performance is weak, the durability is weak. In addition, when less than 65% by weight, the permanent deformation due to external force is large and the elastic performance is poor, which is insufficient for use as an elastic yarn.

Therefore, in the present invention, the content of the polytetramethylene glycol component was increased to 85% by weight in order to increase the elastic performance, and the elasticity due to the molecular chain cleavage was introduced by introducing a specific crosslinking bond to prevent the degradation of the elastic performance during dry and wet heat treatment. The deterioration of the properties was reduced, and specific nucleating agents were formulated to maximize the crystallinity to minimize the permanent deformation due to external force.

The polyether ester block copolymer may be prepared by condensation polymerization of the mixture constituted as described above by esterification or transesterification in a conventional manner.

The polyether ester block copolymer described above can be easily melt-spun and can be stretched and heat treated as necessary to further increase the elastic performance.

The prepared polyether ester block copolymer was dried into pellets, and then melted and wound to obtain an elastic yarn.

Physical properties of the prepared polyether ester block copolymer were measured by the following method.

[Viscosity (IV)]

0.5 g of the polymer was dissolved in 100 ml of offtochlorophenol at 100 ° C. and measured at 35 ° C. and then calculated.

Melting Point (Tm)

It measured using the Perkin-Elmer company DSC 7 at the temperature increase rate of 20 degree-C / min.

Crystallinity

It measured using the wide-angle X-ray scattering method.

[Strength, Shinto]

A 5 cm long sample was stretched at a rate of 1000% per minute to measure the strength and elongation at break.

[Instant recovery rate]

A 10 cm long sample was placed at a load corresponding to 200% elongation, 200% elongated, held for 5 seconds, and then removed from the load to measure the length (L) of the sample and calculated by the following equation.

The following examples and comparative examples illustrate the invention in detail, but do not limit the scope of the invention.

Example 1

116.5 g of dimethyl terephthalate, 81.1 g of tetramethylene glycol, 410.5 g of polytetramethylene glycol with a number average molecular weight of 2000, 0.35 g of tetrabutyl titanate, 0.5 g of Iganox 1010 from Ciba-Gaigyi, and 1,2,4,5-benzene 0.16 g of tetracarboxylic dianhydride was added to the reactor and subjected to a transesterification reaction at an internal temperature of 200 ° C. When about 70% of the theoretical amount of methanol was leaked, 0.5 g of calcium stearic acid was added and stirred for 10 minutes, which was understood as a polycondensation reaction. After decompression was started while raising the temperature, and the pressure was reduced to 30mmHg from the normal pressure over about 30 minutes, and further reduced to 1mmHg branches over 30 minutes, and then subjected to a condensation polymerization reaction at a high vacuum of 1mmHg or less at 245 ° C for 250 minutes. The physical properties of the resulting polymers were evaluated and listed in Table 1.

The resulting polyether ester block copolymer was pelletized, dried and melted at 250 ° C., and wound at an ejection rate of 9.4 g / min and a spinning speed of 1000 m / min through an odd number of 10 nozzles to obtain an elastic yarn. The physical properties of the elastic yarn obtained at this time and the physical properties after dry heat treatment at 160 ° C. for 1 minute are shown in Table 2.

EXAMPLES 2-4, COMPARATIVE EXAMPLES 1-3

The elastic yarns were prepared in the same manner as in Example 1 except that the amounts of 1,2,4,5-benzenetetracarboxylic dianhydride and calcium stearic acid were changed as shown in Table 1. Le was evaluated and shown in Tables 1 and 2.

Claims (3)

1,2,4,5-benzenetetra of the following general formula in the production of a polyetherester block copolymer having a polybutylene terephthalate polyester as a hard segment and a polyoxybutylene glycol polyether as a soft segment A method for producing a polyether ester block copolymer characterized in that a carboxylic dianhydride (1,2,4,5-Benzenetetracarboxylic dianhydride) derivative is reacted by adding a stearic acid metal salt as a crosslinking agent and a crystal nucleating agent. The method of claim 1, wherein the 1,2,4,5-benzenetetracarboxylic dianhydride derivative is used in an amount of 0.05 to 0.7 mol% based on dimethyl terephthalate. The method according to claim 1, wherein the stearic acid metal salt is used in an amount of 0.05 to 3% by weight based on the generated primer.