JPH04175363A - Thermoplastic polyester composition - Google Patents

Abstract

PURPOSE:To improve the moldability of a thermoplastic polyester while maintaining the heat resistance by compounding it with a polyphenylene ether resin and a specific compatibilizer. CONSTITUTION:30-90wt.% thermoplastic polyester is compounded with 70-10wt.% polyphenylene ether resin and 0.5-30wt.% compatibilizer comprising a styrenic polymer contg. monomer units having groups reactive with the polyester. The prepd. compsn. can be molded into various shapes such as films, sheets, injection or extrusion molded items, etc., and is useful in automotive uses, electric and electronic uses, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermoplastic polyester composition having excellent heat resistance and moldability.

[Conventional technology]

Thermoplastic polyester has excellent mechanical properties, electrical properties, solvent resistance, etc., and is therefore widely used in applications such as automobile parts, electrical/electronic parts, and other mechanical parts. However, this thermoplastic polyester also has the problem of poor heat resistance (low heat distortion temperature under high loads).

Therefore, in order to improve heat resistance, methods of filling reinforcing agents such as glass fibers and techniques of blending other thermoplastic resins with high glass transition points have been developed.

However, if a large amount of reinforcing agent is filled, warping is likely to occur, resulting in the problem that it cannot be applied to applications that have strict requirements on appearance and shape, such as electronic components that require fitability.

On the other hand, the technology of blending polyphenylene ether resin with a high glass transition point into thermoplastic polyester is
-2] Publication No. 1364, etc.), thermoplastic polyester and polyphenylene ether resin originally have poor compatibility, so even if they are simply blended, they are brittle and impractical. Therefore, a technique to add a compatibilizer to this was also developed, and was disclosed in Japanese Patent Application Laid-open No. 60-2
No. 21459, Japanese Unexamined Patent Publication No. 60-260649,
This is disclosed in Japanese Patent Application Laid-Open No. 62-27457. Although these techniques improved the heat resistance of thermoplastic polyester and the chemical resistance of polyphenylene ether resin, they had another drawback: adding a compatibilizer led to poor moldability.

[Problem to be solved by the invention]

An object of the present invention is to improve the moldability of a composition containing thermoplastic polyester and polyphenylene ether resin while maintaining the heat resistance of the thermoplastic polyester.

[Means to solve the problem]

The present invention was accomplished in order to obtain a resin composition that is composed of a portion mainly composed of thermoplastic polyester and polyphenylene ether resin and has good heat resistance and moldability.
The present inventors (a) thermoplastic polyester 30-90
Weight 9o, (b) Polyphenylene ether resin 70
(c) 0.5 to 30% by weight of a compatibilizer, and 0.1 to 30% by weight of a monomer component containing a functional group capable of reacting with the compatibilizer or the thermoplastic polyester. It has been found that the above-mentioned problems can be solved in a thermoplastic polyester composition characterized by containing less than .5% by weight of a styrene polymer, and the present invention has been completed.

That is, the present invention provides (a) thermoplastic polyester 30-
90% by weight, (b) polyphenylene ether resin 70
(c) 0.5 to 30% by weight of compatibilizer, in which the compatibilizer contains 0.1% of the monomer component containing a functional group capable of reacting with the thermoplastic polyester.
The present invention provides a thermoplastic polyester composition characterized in that it is a styrenic polymer containing at least 2% by weight and less than 5% by weight of Ti.

The thermoplastic polyester used as component (a) in the present invention may be a known polyester that is normally used for injection molding, extrusion molding, etc. It is a polymer having a -CO〇- bond in the main chain and can be melted by heating. It is something. Specific examples thereof include a dicarboxylic acid component whose main component is terephthalic acid and a diol component. In addition to the above-mentioned terephthalic acid, the dicarboxylic acid component has a carbon number of 2 to 20, such as adipic acid, sebacic acid, and dodecanedicarboxylic acid. Examples include aliphatic dicarboxylic acids, aromatic dicarboxylic acids such as isophthalic acid and naphthalene dicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, singly or in mixtures, and diol components include ethylene glycol, propylene glycol, and tetramethylene glycol. , aliphatic glycols such as hexamethylene glycol, and aromatic diols such as alicyclic diols such as 1,4-cyclohexanediol, either singly or in mixtures.

Further, a small amount of a polybasic acid such as trimellitic acid as a carboxylic acid component or a polyhydric alcohol such as glycerin as a diol component may be used.

Particularly preferred thermoplastic polyesters include polyethylene terephthalate and polybutylene terephthalate.

The thermoplastic polyester preferably has an intrinsic viscosity of 0.4 or more, more preferably 0.65 or more, as measured at 30° C. in a phenol/tetrachloroethane mixed solution (6/4 weight ratio).

In the present invention, the polyphenylene ether resin used as component (b) has the following formula (wherein R1, R2, R3, and R4 are alkyl groups having 1 to 4 carbon atoms excluding the same or different tert-butyl groups). basis,
It is a monovalent residue such as an aryl group, hydrogen, /%rogen, etc., and R1 and R2 are not hydrogen at the same time. ) as a repeating unit, a homopolymer or copolymer consisting of a structural unit,
and a graft copolymer obtained by graft-polymerizing styrene or the like onto the polymer. Its reduced viscosity (0.5g/
dl, chloroform solution, measured at 30°C) is 0.1
5 to 0.70, more preferably 0.20 to 0.
The range is 60.

Specific examples include poly(2,6-dimethylphenylene-1,4-ether), poly(2,6-diethylphenylene-1,4-ether), and poly(2,6-cyclophenylene). -1,4-ether), poly(2,6-diprophenylene-1,4-ether), poly(2-methyl-6-nitylphenylene=1,4-ether), poly(2-chloro-6 -methylphenylene-1,4-ether), poly(2-methyl-6-itubrobylphenylene-1,4-ether), poly(2,6-di-n-propylphenylene-1,4-ether) , poly(2-chloro-6-promphenylene-1,4-ether), poly(
2-chloro-6-ethylphenylene-1,4-ether), poly(2-methylphenylene-1,4-ether)
, poly(2-chlorophenylene-1,4-ether)
, poly(2-phenylphenylene-1,4-ether)
, poly(2-bromo-6-phenylphenylene-1,4
-ether), their copolymers, and their styrenic compound graft copolymers.

In the present invention, a polyphenylene ether resin bonded with molecular units containing carboxylic acid groups or derivative groups thereof may be used as component (b).

In the present invention, the compatibilizer used as component (c) is a styrene polymer containing 0.1% by weight or more and less than 2.5% by weight of a monomer component containing a functional group capable of reacting with the thermoplastic polyester. . Functional groups that can react with thermoplastic polyester include carboxylic acid and its derivative groups,
These are epoxy groups, acid anhydride groups, oxazoline groups, isocyanate groups, amino groups, etc., and refer to functional groups that can react with hydroxyl groups and carboxyl groups in thermoplastic polyester.

The amount of functional groups is determined as follows:
0.1% by weight or more and less than 2.5% by weight. Preferably it is 0.5% by weight or more and less than 2.5% by weight. If it is less than 0.1% by weight, the effect as a compatibilizer is insufficient, and if it is 2.5% by weight or more, moldability is poor.

Among the compatibilizing agents, styrene polymers containing epoxy groups are preferred, and examples include glycidyl methacrylate-styrene copolymers.

In the present invention, the composition ratio of the resin component is such that the amount of thermoplastic polyester blended is in the range of 30 to 90% by weight, more preferably 40 to 85% by weight. If it is less than 30% by weight,
This is not preferable because it becomes difficult for the thermoplastic polyester to form a continuous phase, which may result in a decrease in oil resistance, which is a characteristic of thermoplastic polyesters. If it exceeds 90% by weight, the effect of improving heat resistance by adding the polyphenylene ether resin will be significantly reduced, which is not preferable.

The blending amount of the polyphenylene ether resin is in the range of 70 to IO weight percent, more preferably 65 to 20 weight percent.

If it is less than 10% by weight, the effect of polyphenylene ether resin formulation, such as improvement in heat resistance and dimensional stability, will be small.
If it exceeds 70% by weight, molding processability will be significantly reduced, which is not preferable.

The blending ratio of the compatibilizer is in the range of 0.5 to 30% by weight, preferably 1 to 20% by weight. If it is less than 0.5% by weight,
The effect of improving compatibility is insufficient, and if it exceeds 30% by weight, moldability, heat resistance, etc. will decrease.

In the resin composition of the present invention, an elastomer may be added as necessary.

The elastomer that can be used in the present invention is intended to improve impact resistance and is a rubber-like substance at room temperature that has a glass transition temperature of 0° C. or lower.

For example, polybutadiene, styrene-butadiene copolymer, styrene-isoprene copolymer, acrylonitrile-styrene-butadiene copolymer, ethylene-α-olefin copolymer, ethylene-α-olefin-polyene copolymer, acrylic ester Copolymer, rubbery polymer such as polyisoprene, styrene-butadiene block copolymer, styrene-isoprene block copolymer, hydrogenated styrene-butadiene block copolymer, styrene-grafted ethylene-propylene elastomer, ethylene Examples include thermoplastic elastomers such as ionomer resins, and these polymers may be modified with compounds containing functional groups such as carboxyl groups, acid anhydride groups, epoxy groups, hydroxyl groups, and amino groups.

Preferred elastomers include styrene-butadiene copolymers, ethylene-α-olefin copolymers, styrene-butadiene block copolymers, and hydrogenated styrene-butadiene copolymers. Is it modified with chemical groups, epoxy groups, etc.
More preferably, these are disclosed in, for example, JP-A-58-7443.
It can be manufactured by a known method such as the method described in the above publication.

In the present invention, there is no particular restriction on the kneading order, and it may be a method in which all components are kneaded at once, or a method in which components other than the thermoplastic polyester are kneaded in advance, and then the thermoplastic polyester is added and kneaded.

The resin composition of the present invention may contain other ingredients such as pigments, dyes, heat stabilizers, antioxidants, weathering agents, nucleating agents, lubricants, and plasticizers within the range that does not impair its moldability and physical properties. , antistatic agents, reinforcing agents, fillers, flame retardants, other polymers, etc. can be added during any manufacturing/forming process.

The resin composition of the present invention can be prepared by mixing in a molten state using various mixing apparatuses commonly used for mixing polymeric substances. Suitable mixing devices include, for example, a single-screw or multi-screw extruder, a mixing roll, a Banbury mixer, a kneader, a Brabender, and the like.

The resin composition of the present invention can be easily processed into molded articles of various shapes by any conventionally known molding method, such as injection molding, extrusion molding, blow molding, etc.

The resin composition of the present invention having the above structure has excellent heat resistance and good moldability.

The resin composition of the present invention can be made into a wide variety of practically useful products such as films, sheets, injection molded products, and compression molded products.

〔Example〕

The present invention will be described below with reference to Examples, but the present invention is not limited thereto. In the examples, "parts" indicate "parts by weight."

In addition, the physical properties of the resin compositions in Examples were measured by the following method.

1) Measurement of melt viscosity This is a measure for evaluating molding processability, and the lower the melt viscosity, the better the molding processability.

Using a cavilograph model IB made by Toyo Seiki, the piston descending speed is +00 stops/min, and the diameter is 1. The apparent melt viscosity was measured by extrusion from the orifice of RNRS at a shear rate of 1218 sec-'.

2) Using an injection molded piece with a heat distortion temperature of 1/8' thickness, ^STM D-64
8, the heat distortion temperature was measured at a load of 18.8 kg/cd.

Examples 1 to 3, Comparative Example 1 After tri-blending the components shown in Table 1 with the composition shown in Table 2, a co-rotating twin-screw extruder (Plastics Institute ■Made by B
T-40, diameter 40+nmφ, L/D-36), the mixture was melt-kneaded, cooled, and then pelletized to obtain a pelletized resin composition.

After drying this resin composition at 130°C for 6 hours,
Melt viscosity was measured at 0°C. A test piece for measuring physical properties was produced by injection molding at a cylinder temperature of 250°C and a mold temperature of 80°C.

The obtained physical properties are shown in Table 2.

The composition of the present invention had excellent heat resistance and moldability, but the compositions other than the compositions of the present invention shown as comparative examples had poor moldability.

Example 4, Comparative Example 2 After tri-blending the components shown in Table 1 with the composition shown in Table 2, Examples 1 to 2 were prepared at a cylinder temperature of 280°C.
The mixture was melt-kneaded in the same manner as in 3, cooled, and then formed into pellets to obtain a pellet-shaped resin composition.

After drying this resin composition at 130°C for 6 hours,
Melt viscosity was measured at 0°C. A test piece for measuring physical properties was prepared by injection molding at a cylinder temperature of 270°C and a mold temperature of 120°C.

The obtained physical properties are shown in Table 2.

The composition of the present invention had excellent heat resistance and moldability, but the compositions other than the present invention shown in comparative examples had poor moldability.

〔Effect of the invention〕

As is clear from the above, according to the present invention, it is possible to provide a thermoplastic polyester composition that has excellent heat resistance and good moldability.

The resin composition of the present invention can be made into a wide variety of practically useful products such as films, sheets, injection molded products, and compression molded products, and can be used for automotive applications, electrical and electronic applications, etc. can.

For example, it can be used for automobile outer panels, automobile connectors, roof frames, site brakes, blower fans, ski boards, ski binders, jet ski outer panels, electrical/electronic connectors, sockets, housings, chassis, etc.

(Margin below)

Claims (2)

[Claims] (1) In a composition consisting of (a) 30 to 90% by weight of thermoplastic polyester, (b) 70 to 10% by weight of polyphenylene ether resin, and (c) 0.5 to 30% by weight of compatibilizer, the compatibilizer is 0.1% by weight or more of a monomer component containing a functional group capable of reacting with thermoplastic polyester 2.5%
A thermoplastic polyester composition comprising less than % by weight of a styrenic polymer. (2) The thermoplastic polyester composition according to claim 1, wherein the functional group capable of reacting with the thermoplastic polyester is an epoxy group.