JPS58141236A - Polyester elastomer composition - Google Patents

Abstract

PURPOSE:To provide a polyester elastomer compsn. which has excellent elasticity characteristics and contains a hard segment having improved crystallizability, by adding a sepcified polybutylene terephthalate. CONSTITUTION:A high-melting polybutylene terephthalate having an m.p. of 231 deg.C or higher (endothermic peak temp. measured with a differential calorimeter at a heating rate of 20 deg.C/min) is used. 0.01-10wt% said polybutylene terephthalate is blended with a polyester elastomer in which a hard segment is composed of an arom. polyester, such as a polyester of which the acid component is composed of terephthalic acid and the alcohol component is composed of tetramethylene glycol, and a soft segment is composed of a polyether such as polytetramethylene glycol.

Description

[Detailed description of the invention] The present invention relates to polyester elastomer 11 compositions.

The purpose is to provide an elastomer composition with improved crystallinity of the hard segment and excellent elastic properties.

Polyester elastomers, which have aromatic polyester as a hard segment and polyether as a soft segment, have traditionally attracted attention as elastomers capable of melt molding. Located in the area of plastics, it was first invented that it was used as a wax, and it has since been used for some molded products, coating agents, etc.

This elastomer has elasticity by suppressing the fluidity of molecules in the soft segment by the crystal cohesive force of the hard segment.

Lowering the secondary dislocation point of the knot segment (and improving the crystallinity of the hard segment) are important factors in improving the elastic properties. Ninth, it is elastic, and it is not just a crystal nucleating agent, but a photo II agent with a large ratio IIIk has a great effect. If so, we have found that it has the same effect and have arrived at the present invention.

That is, the present invention provides Boriesderst, which uses an aromatic polyester as an 8-do segment and a polyneedle T soft segment! - D. A polyester elastomer composition characterized by blending more than 0.01-10 times of polybutylene terephthalate with a melting point of 231C or more at one point.

In the present invention, the "aromatic polyester" constituting the hard segment is a polyester containing an aromatic dicarboxylic acid as the main acid component and an aliphatic dihydroxy compound as the main glycol component. The term "main" here usually means 80 moles or more of S at the repeating position, and other components of up to 20 moles of F may be copolymerized.

In the present invention, the aromatic dicarboxylic acid is pre-7.
Examples include thalamic acid, isophthalic acid, sodium dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, etc., and all acid components have the same SO molar ratio or more. It is preferable that the acid consists of

Examples of 111 aliphatic & hydroxy compounds include ethylene glycol, trimethylene glycol, detramethylene glycol, pentamethylene yv col, hexamethylene glycol, etc., and more than the sO molar capsule of all glycol components may be composed of the same dihydroxy compound. preferable.

Among these, the combination #17 of pre-7 talsen-dettumethylene glycol is particularly preferred.

The sulfoliether constituting the soft segment of the elastomer of the present invention means a polymer of the aliphatic glycol listed above, and specifically, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, or a copolymer thereof. Illustrated. The molecular weight of such polyether is preferably 500-600G, soo-5oo
o is particularly preferred. Among these, polytetramethylene glycol is particularly preferred.

In the composition of the present invention, it is necessary to blend a high melting point polybutylene terephthalate with a weight of αo1 to eo.

In particular, 1^ melting point polybutylene terephthalate” (hereinafter [
high melting point PBTJ)
/min to reach the endothermic peak temperature, that is, the melting point (Tm'
C) refers to polybutylene terephthalate with a temperature of 231°C or higher. Polybutylene terephthalate, which is conventionally produced and commercially available, has a melting point of 220 to 230°C and a total ILK of about 225 to 228°C, and it is also known that it has two types of crystal structures: am + β type. ing. However, the high single point PBT used in the present invention is a polymer with a melting point of 231C or higher, preferably 235C or higher, and a f of 240C or higher, and it is not clear whether its crystal structure is the same as that of conventional ones. , the I4 melting point PBT is normal PBT
, N IJ Mama - Near melting point 1 For example, it can be obtained by heat treatment at around 200° C. for several tens of hours [4 hours].

The high melting point PBT has a similar molecular structure to the polyester elastomer of the Luhes polymer, which is the matrix to which it is blended, and has a strong crystallization promoting effect even in a small amount, probably because it has an affinity.

Here, the "crystallization promotion effect" is defined by raising the temperature to 250 °C at a rate of 20 °C/min in a nitrogen atmosphere with a differential calorific value needle, and then increasing the temperature to 250 °C.
After holding for a minute, the difference between the exothermic peak salt 1 ('rca°C) and the endothermic peak (Tm'C) when the temperature is lowered at 7°C/min is 6T.
(=Tm-Tea) means that it is large.

In the present invention, the blending amount of the high melting point PBT is aot-t
It is necessary to have an o-type weight. If the weight is less than αO1 weight, the effect of promoting crystallization is small, and if the weight exceeds the reverse KIG weight, although there is a promoting effect, it becomes brittle and has a foreign body feeling. Hime gets worse. Also, when molding into fibers, films, etc., the puncture pressure, filter filtration pressure, etc. are easily affected. Preferably αos-st weight-, l! preferably a1~
Although the method for blending into the PBTt polynisder elastomer is arbitrary, for example, the following method is available. First, the melting point PBT is adjusted to an average particle diameter of bus or less, preferably 20
m more de, I! It is preferably ground to i# or less.

Next, polynisder elastomer KeI! is prepared in the following manner. , match.

l. The high melting point PBT powder is added at the final stage of polymerization of the polynisdel elastomer, and the mixture is discharged using a stirring mixer.

2 Polyester elastomer perent high melting point PBT
are mechanically mixed using a mixer such as a tumbler or a blender, and the mixture is directly subjected to m-forming.

The polynisdel elastomer blended with high melting point PBT as proposed in U.2 is once extruded in a bath, made into a pellet with a pelletizer, and then subjected to melt molding.

A fixed amount of high melting point PBT is supplied to the supply section or pent section, mixed into the polyester elastomer, and molded as it is.

i ＾Melting point PBT is mixed into the polynisdel elastomer while being supplied in a constant quantity from the extrusion rod supply part or the pet/to part, and then the polyester elastomer is extruded and pelletized with a pelletizer, followed by #I melt molding. Serve.

The polynisdel elastomer composition of the present invention has excellent crystallinity and provides molded articles with good elastic properties.

Molded products include regular injection molded products, extrusion molded products,
Film *Including m, etc.

The present invention will be specifically explained below with reference to Examples. In the examples, all parts represent parts by weight, and the intrinsic viscosity is calculated from the solution viscosity of the ortsucumylophenol solution at 35° C. in temperature. Father, TmFi, constant endothermic peak temperature (℃) by heating at p20 with differential calorific value needle
, that is, one point, and Tcd is the endothermic peak temperature when the temperature is raised to traac at a rate of 20°C/min in a nitrogen atmosphere with a differential calorific value needle, held there for 3 minutes, and then lowered at a rate of 7°C/min. [(℃). Furthermore, the elongation modulus of hO is J-5L1
071 (197?) Synthetic Iron - Based on the elongation modulus method of the test method, the elongation modulus at the time of 50 elongation is kept constant.

夷1IIA? II 凰～ & Comparative Example 1-2 Nmetal Dere 7 Yo V-) 147 parts, detramethylene glycol 10
0i11. 244 parts of polytetramethylene glycol having a number average molecular weight of 200G and 31 parts of tetrabutyl titanate (tetrabutyl titanium) were charged into a reactor and a transesterification reaction was carried out at an internal temperature of 170°C.

When methanol of 80% of the amount of salt was released, the system was heated to 17°C, and the pressure was reduced to 30°C over about 30 minutes.
! 3. Take Kao minutes. As a phase, a reaction was then carried out for 240 minutes at an internal temperature of 245° C. under a vacuum of 1 μg of F. The hardness of the obtained polymer was 1.40.

A predetermined amount of various high melting point PBT listed in the following table was blended into this polynisder elastomer, mixed in a tumbler, and then melt-extruded in an extruder to form a belent. The crystallization behavior of this compounded elastomer pellet was as shown in the center of the same table.

The pellets were spun into mortar I# at 260°C to obtain a 135 denier elastic yarn. The elastic modulus of this elastic yarn at 60 elongation is as shown in the right column of the same table.

As is clear from this result, one point is 7m) 231m
: The above elastomer composition (Example 1-5) to which OA high melting point B'r was added had a remarkable positive effect on promoting crystallization! The elastic properties are greatly improved. On the other hand, the melting point of the one without the addition of PBT (ratio *?11) is high! 31
No. 94 (Comparative Example 2) in which less than 11:1 PBT was added had no crystallization promoting effect and had poor elastic properties.

Procedural amendment document 1975 IJ-Kaku 30th Mr. Commissioner of the Patent Office 1, Indication of the case Patent application Sho my-zxtst No. 2, Name of the invention Polyester elastomer composition 3 Relationship with the case by the person making the amendment Patent applicant Osaka City Higashi 1-11 Minamihonmachi, Ward (300) Teijin Ltd. Representative Tomo Tokusue@-, page 6, rows 6 to 6 "ΔS(=Tm-T)
cd) is big t'ml tb #J'
It is represented by ΔT (=Tac-Tcd), and a small M means that the "crystallization promoting effect" is large. ” he corrected.

that's all

Claims (1)

[Claims] A polyester elastomer composition comprising a polynisder elastomer having an aromatic polynisder as a hard segment and a polyether as a knot segment, and a high melting point polybutylene terephthalate having a melting point of 231C or higher (α01 to 10% by weight) blended therein.