JPS6369857A - Thermoplastic resin composition - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a novel composition comprising polyphenylene oxide and polyester resin.

More specifically, it consists of polyphenylene ether and high molecular weight polyester, each having a specific intrinsic viscosity.
It relates to a polyphenylene ether resin composition that has excellent dispersibility, mechanical strength, solvent resistance, oil resistance, and moldability.

(Problems with the Prior Art) Polyphenylene ether is a resin with excellent heat resistance, mechanical strength, and electrical properties, and is a polymeric material useful as engineering plastics. However, it is well known that polyphenylene ether has major drawbacks such as poor solvent resistance, poor oil resistance, and poor moldability as a non-crystalline resin.

As a technique for improving the moldability of polyphenylene ether, a technique of blending polystyrene resin is disclosed in US Pat. No. 3,383,435.

However, these techniques do not improve the solvent resistance and oil resistance of polyphenylene ether at all.

On the other hand, Japanese Patent Publication No. 51-21664 discloses a technique for improving the moldability, that is, the fluidity, of polyphenylene ether by blending a polyester resin with the polyphenylene ether.

However, according to the inventors' study,
Although blending polyester certainly improves the fluidity of polyphenylene ether, when polyester is blended in an amount that accounts for 20% or more by weight of the composition, the inherent mechanical strength of polyphenylene ether is It has become clear that this results in a significant loss of

This is considered to be because polyphenylene ether and polyester resin essentially do not mix, and as the amount added increases, phase separation occurs. Facts Special Publication 1977-2166
The specification of Publication No. 4 states that the mixed composition of polyphenylene ether and polyester "has a pearl-like color tone and is opaque," indicating that the polyphenylene ether and polyester are not sufficiently finely mixed. First, it is non-uniformly dispersed, indicating that phase separation has occurred.

Furthermore, when a polyester resin is blended with polyphenylene ether, the solvent resistance of the polyphenylene ether is improved, but the degree of improvement in solvent resistance is proportional to the amount of polyester resin blended. Therefore, in order to provide sufficient solvent resistance, a large amount of polyester resin must be blended, and as mentioned above, the resulting resin composition is non-uniform, prone to phase separation, and mechanically This has the undesirable effect of reducing the strength of the target.

In order to solve these problems, it is necessary to improve the compatibility between polyphenylene ether and polyester resin. It is disclosed that a resin) is used to intervene.

(Summary of the present invention) In blending polyester resin sufficient to impart solvent resistance, oil resistance, and moldability to polyphenylene ether, the present inventors improved the uniform dispersibility of both components, and The present invention was arrived at as a result of intensive study on how to maintain the excellent mechanical strength inherent in steel.

Polyphenylene ether and polyester resins exhibit very different viscosity behavior during their melt-kneading.

In other words, polyphenylene ether, which is an amorphous resin, has extremely high viscosity when melted, but polyester resin, which is a crystalline resin, rapidly decreases in viscosity at temperatures above its melting point, and the viscosity of both components during melt-kneading increases. The viscosity difference is extremely large.

In order to uniformly disperse polyphenylene ether and polyester resin, the present inventors focused on the viscosity difference between the two components during melt-kneading, and by reducing the viscosity difference, the dispersion energy during melt-kneading was applied to both components. We have discovered that it is important to achieve a sufficient level, and have completed the present invention.

That is, the present invention is a mixture of (10 to 80% by weight of polyphenylene ether having an intrinsic viscosity of 0.35 to 0.55 as measured at 30°C in al chloroform and (b) phenol and tetrachloroethane in a 1:1 weight ratio). Polyester resin 90 with an intrinsic viscosity of 0.75 or more measured at 30°C in a solvent
The present invention provides a resin composition which has excellent solvent resistance, oil resistance, moldability, homogeneous dispersibility, and mechanical strength, and which is obtained by melt-kneading 20% by weight of the above.

The polyphenylene ether used in the resin composition of the present invention is a polyphenylene ether obtained by polycondensing one or more monocyclic phenols represented by the general formula (1), and this polyphenylene ether is R1 is a lower alkyl group having 1 to 3 carbon atoms, R2
and R3 is a hydrogen atom or a lower alkyl group having 1 to 3 carbon atoms, and a lower alkyl substituent must always be present at the ortho position of at least one of the hydroxyl groups. ) Includes a graft copolymer having polyphenylene ether as its core, which is obtained by graft polymerizing a vinyl aromatic compound to rene ether. This polyphenylene ether may be a homopolymer or a copolymer of two or more types of monocyclic phenols.

Examples of the monocyclic phenol represented by the general formula (11) include 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-dipropylphenol, 2-
Methyl-6-ethylphenol, 2-methyl-6-propylphenol, 2-ethyl-6-propylphenol, m-cresol, 2.3-dimethylphenol, 2.
3-diethylphenol, 2,3-dipropylphenol, 2-methyl-3-ethylphenol, 2-methyl-
3-propylphenol, 2-ethyl-3-methylphenol, 2-ethyl-3-propylphenol, 2-brobyl-3-methylphenol, 2-propyl-3-ethylphenol, 2,3.6-)dimethylphenol , 2,3.6-) diethylphenol, 2.3.6-
Examples include doliprovirphenol, 2,6-dimethyl-3-ethylphenol, 2,6-dimethyl-3-propylphenol, and the like. Examples of polyphenylene ether obtained by polycondensation of one or more of these phenols include poly(2,6-cymethyl-1,4-
phenylene) ether, poly(2,6-diethyl-1,
4-phenylene) ether, poly(2,6-diprobyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly
(2-methyl-6-broby-1,4-phenylene) ether, poly(2-ethyl-6-broby-1,4-phenylene) ether, 2,6-dimethylphenol/2
, 3.6-trimethylphenol copolymer, 2,6-dimethylphenol/2,3.6-1-diethylphenol copolymer, 2,6-diethylphenol/2,3.6
-1-rime-f-)Ii mitsuenol polymer, 2,6-
Diprobylphenol/2,3.6-1-dimethylphenol copolymer, graft copolymer of styrene grafted onto poly(2,6-dimethyl-1,4-phenylene) ether, 2,6-dimethylphenol /2,3.
Examples include a graft copolymer obtained by graft-polymerizing styrene onto a 6-trimethylphenol copolymer. In particular, poly(2,6-dimethyl-1,4-phenylene) ether, 2,6-dimethylphenol/2,3,6-trimedelphenol copolymer, and graft polymers in which styrene is graft-polymerized to each of the former two are used. Polymers are preferred as the polyphenylene ether resin used in the present invention.

The polyphenylene ether used in the present invention has an intrinsic viscosity of 0.35 to 0.55 measured in chloroform at 30°C.
A value in the range of 0.40 to 0.50 is particularly preferred. A composition having an intrinsic viscosity of 0.35 or less is undesirable because the resulting composition will be brittle and its mechanical strength will decrease. Further, when polyphenylene ether having an intrinsic viscosity of 0.55 or more is used, the difference in viscosity from the polyester resin is too large when melt-mixing with the polyester resin, making it impossible to obtain a good dispersion state.

The polyester resin used in the resin composition of the present invention refers to a high molecular weight thermoplastic resin having an ester bond in the main chain of the molecule. Polycondensation products obtained from a dicarboxylic acid or its derivative and a cyclic ether compound; Polycondensation products obtained from a metal salt of a dicarboxylic acid and a dihalogen compound; Opening of a cyclic ester compound Examples include ring polymers. Here, the 8'R4 form of dicarboxylic acid refers to an acid anhydride, an ester, or an acid chloride. The dicarboxylic acid may be aliphatic or aromatic, and examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, fucuric acid, chlorophthalic acid, nitrophthalic acid, p-carboxylphenylacetic acid, p- Phenylene diacetic acid, m-phenylene diglycolic acid, p-phenylene diglycolic acid, diphenylethane, diphenyl-p1
p'-dicarboxylic acid, diphenyl-m, m'-dicarboxylic acid, diphenyl-4,4'-diacetic acid, diphenylmethane-p, p'-dicarboxylic acid, diphenylethane-m,
m'-dicarboxylic acid, stilhensylcarboxylic acid, diphenylbutane-p,p'-dicarboxylic acid, benzophenone-4,4'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid , naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-
Dicarboxylic acid, p-carboxyphenoxyacetic acid, p-carboxyfetoxydibutyric acid, 1,2-diphenoxypropane-p, ρ'-dicarboxylic acid, 1,3-diphenoxypropane-p, p'-dicarboxylic acid, 1 , 4-diphenoxybutane-p,p'-dicarboxylic acid, 1,5-diphenoxypentane-p,p'-dicarboxylic acid, 1,6-
Diphethoxybentane-p+p'-dicarboxylic acid, p-
(p-carboxyphenoxy)benzoic acid, 1,2-bis(2-methoxyphenoxy)-ethane-p.

p'-dicarboxylic acid, 1,3-bis(2-methoxyphenoxy)-propane-p,p'-dicarboxylic acid, L4-
Bis(2-methoxyphenoxy)-butane-ρ+p'-
dicarboxylic acid, 1,5-bis(2-methoxyphenoxy)-3-oxapentane-p,p'-dicarboxylic acid, etc., and aliphatic dicarboxylic acids include:
For example, oxalic acid, succinic acid, adipic acid, succinic acid,
Examples include azelaic acid, sebacic acid, dodecanedicarboxylic acid, undecanedicarboxylic acid, maleic acid, fumaric acid, and the like. Examples of preferred dicarboxylic acids are aromatic dicarboxylic acids, and more preferred are terephthalic acid, isophthalic acid, and phthalic acid.

Examples of dihydric alcohols include ethylene glycol, propylene glycol, trimethylene glycol, butane-1,3-diol, butane-1,4-diol, and
．． 2-dimethylpropane-1,3-diol, cis-
2-butene-1,4-diol, trans-2-butene-1,4-diol, tetramethylene glycol,
Examples include pentamethylene glycol, hexamethylene glycol, heptamethylene glycol, octamethylene glycol, decamethylene glycol, and the like. Examples of preferred dihydric alcohols are ethylene glycol, propylene glycol, trimethylene glycol, butane-1,
4-diol or butane-1,3-diol, more preferably ethylene glycol and butane-1,3-diol.
Mention may be made of 1,4-diols. Examples of dihydric phenol compounds include hydroquinone, resorcinol, bisphenol A, and the like.

Examples of the cyclic ether compound include ethylene oxide and propylene oxide, and examples of the cyclic ester compound include δ-valerolactone and ε
- Mention may be made of caprolactone. The dihalogen compound to be reacted with the dicarboxylic acid metal salt refers to a compound obtained by replacing two hydroxyl groups of the dihydric alcohol or dihydric phenol compound with halogen atoms such as chlorine or bromine.

The polyester resin used in the resin composition of the present invention is produced by a known method using the above-mentioned raw materials, and its molecular weight is kept high in order to maintain uniform dispersibility with polyphenylene ether. There is a need. The polyester used in the present invention has an intrinsic viscosity of 0.75 or more, preferably 0.75 or more, as measured at 30°C in a 1=1 weight ratio mixed solvent of phenol and tetrachloroethane.
．． A value of 80 or more, more preferably 0.90 or more is used. The upper limit of the intrinsic viscosity is not particularly limited, but is generally about 1.5. If the intrinsic viscosity is 0.75 or less, the difference in viscosity between the two components will be too large during melt mixing with polyphenylene ether, impairing uniform dispersibility, which is not preferable.

The blending amount of polyphenylene ether and polyester resin in the present invention is 10 to 80% by weight of polyphenylene ether at the intrinsic viscosity specified as above.
, 90 to 20% by weight of polyester resin, preferably 20 to 70% by weight of polyphenylene ether, more preferably 25 to 55% by weight, and 80 to 30% by weight of polyester, still more preferably 75 to 40% by weight. If the amount of polyphenylene ether is too large, the effect of improving oil resistance and solvent resistance will be insufficient, and if it is too small, uniform dispersibility will be poor, which is not preferable.

Depending on the purpose, the composition of the present invention may further contain a polyester resin crystal nucleating agent such as talc or mica.

Titanium oxide, carbon blank, etc., crystallization promoters such as polyalkylene glycols, polyhydric alcohols, higher fatty acid esters, higher fatty acid metal salts, carboxylic acid metal base-containing polymers, etc. may be blended. In addition, antioxidants, ultraviolet absorbers, plasticizers, lubricants, flame retardants, flame retardant aids, antistatic agents, conductivity imparting agents, colorants, polyfunctional crosslinking agents, fibrous reinforcing agents such as glass fiber, rubber, etc. Additives such as impact modifiers can be added.

The method for producing the composition of the present invention is not particularly limited as long as both components are melted and kneaded, and any method may be used. For example, an extruder.

A roll mill, Banbury mixer, Brahender plasto mill, etc. are used.

(Example) The present invention will be explained below with reference to Examples. A predetermined amount of poly-2,6-dimethylphenol (manufactured by Mitsubishi Yuka Co., Ltd.) whose intrinsic viscosity measured at 30°C in chloroform is as shown in Table 1, in a mixed solvent with a 1:1 weight ratio of phenol and tetrachloroethane. A predetermined amount of polyester resin (manufactured by Kuraray Co., Ltd., Tarabet) whose intrinsic viscosity measured at 30°C is as shown in Table 1 was mixed in a blender, and the mixture was mixed using a 30φ twin screw extruder (manufactured by Ikegai Tekko Co., Ltd., PCM-30). The cylinder temperature is 280
The mixture was melt-kneaded at ℃ to form pellets. The obtained pellet was dried in a ventilation dryer at 120° C. for 5 hours, and then a molded product was obtained with an injection molding machine (manufactured by Japan Steel Works, Model N-100). The molding conditions are: cylinder temperature 280℃, injection pressure 1000K.
g/cL mold temperature was 70°C.

The surface appearance of the obtained molded product was observed, and a part of the molded product was sampled and the dispersion state was measured using a scanning electron microscope with a magnification of 2000 times. Furthermore, the Izot impact strength of the test piece having a thickness of 3.2*m was measured according to a conventional method.

The results are shown in Table-1.

(Effects of the Invention) As shown in Table 1 and Examples 1 to 5, the composition of the present invention has significantly improved compatibility between polyphenylene ether and polyester resin, exhibits a smooth surface appearance, and has a polyester matrix. The dispersed polyphenylene ether particles are extremely fine and uniformly dispersed with a size of 1 to 5 microns. As a result, the Izot impact strength is also greatly improved. On the other hand, as shown in Comparative Examples 1 to 3, compositions other than those of the present invention exhibit non-uniform dispersion, exhibit an opaque pearl-like appearance, and have extremely large dispersed particle diameters. It is thought that this resulted in a decrease in impact strength.

Claims (1)

[Claims] Intrinsic viscosity measured at 30°C in chloroform is 0.35~
10 to 80% by weight of polyphenylene ether having a viscosity of 0.55 and 90 to 20% by weight of a polyester resin having an intrinsic viscosity of 0.75 or more as measured at 30°C in a mixed solvent of 1:1 weight ratio of phenol and tetrachloroethane. A resin composition obtained by melting and kneading the following.