JPS63189424A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent impact resistance, tensile strength and moldability, by using an aromatic polyester and a specific modified olefinic polymer as essential components. CONSTITUTION:The objective composition contains (A) an aromatic polyester (preferably polyethylene terephthalate having an intrinsic viscosity of >=0.55) and (B) a modified olefinic polymer derived from an allyl compound having epoxy group (e.g. polyoxyethylene monoallyl glycidyl ether) and an alpha-olefin (preferably ethylene or butene-1).

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a polyester resin composition with improved mechanical properties including impact resistance and moldability.

(Prior Art) Aromatic polyesters represented by polyethylene terephthalate and polybutylene terephthalate are used in a wide range of products such as electrical and electronic equipment parts and automobile parts due to their excellent properties. However, aromatic polyesters are inferior in impact resistance, particularly in the notched impact method, and many improvement methods have heretofore been proposed. For example, a method of grafting glycidyl methacrylate (GMA) onto an α-olefin is known, as disclosed in Japanese Patent Publication No. 58-47419. However, when attempting to produce these modified products at low cost, a melt grafting method is adopted, but in the case of melt grafting of GMA with an α-olefin, the homopolymer of GMA is generated. Therefore, when such a modified olefin is blended with PET, partial gelation occurs during the cross-crossing process and a significant increase in melt viscosity occurs, which significantly deteriorates moldability. Also, impact resistance is insufficient.

(Means and effects for solving the problem) The inventors of the present invention have conducted intensive studies to improve the above problem, and as a result, have arrived at the present invention. That is, the present invention relates to aromatic polyester (
This is a polyester resin composition characterized by containing A) and a modified olefin polymer (B) obtained from an allyl compound having an epoxy group and an α-olefin.

The aromatic polyester (A) used in the present invention is polyethylene terephthalate or a copolymerized polyester containing at least 80% or more, preferably 90% or more of ethylene terephthalate repeating units. As the copolymerization component, conventionally known acid components and/or glycol components can be used.

That is, as copolymerization components, for example, isophthalic acid, naphthalene 1,4- or 2,6-dicarboxylic acid, diphenyl ether 4,4-dicarboxylic acid, adipic acid,
Acid components such as sebacic acid, propylene glycol, butylene glycol, diethylene glycol, neopentyl glycol, cyclohexane dimetatool, 2,2-
Examples include glycol components such as bis(4-hydroxyphenyl)propane, oxyacids such as P-oxybenzoic acid, and P-hydroxyethoxybenzoic acid. In addition,
The polyester preferably has an intrinsic viscosity of 0.5 or more, as determined by measurement at 30°C with a phenol/tetrachloroethane mixed solvent (674 weight ratio) solution, more preferably 0.
．． It is particularly preferable that it is 55 or more.

Next, the modified olefin polymer (B) used in the present invention is obtained by grafting an allyl compound having 0.1 to 15% by weight of an epoxy group to an α-olefin. Also, α-olefins include propylene, butene-1
, ethylene, pentene-1,3-methylpentene-1,
Octacene-1, etc., and ethylene and butene-1 are more preferably used. An allyl compound having an epoxy group that is graft-reacted to an α-olefin to obtain a modified α-olefin is a compound having an allyl group represented by (I) and an epoxy group represented by (II) in the molecule.

CH,=CH-CH,-(I) Specific examples include polyoxyethylene monoallyl glycidyl ether, polyoxypropylene monoallyl glycidyl ether, metaallyl glycidyl ether, allyl glycidyl ether, among which allyl glycidyl ether I like it.

Can be used for many purposes. Two of these monomers may be used in combination.

The amount of graft reaction of allyl compound having epoxy group is 0
．． It is preferably 1 to 15% by weight, more preferably 0.5 to 6% by weight. If it is less than 0.1% by weight, the impact resistance will not be improved sufficiently, and if it is more than 15% by weight, the graft polymer itself will lose its flexibility, which is not preferable.

The modified olefin polymer can be produced by various methods, but for example, it can be easily produced by adding a glycidyl ether compound to the above-mentioned α-olefin and melt-kneading the mixture at 100 to 250°C. As an apparatus for melt-mixing, a screw extruder, a Banbury mixer, etc. can be used.

In addition, when melt-kneading, the graft reaction can be efficiently caused by using 0.01 to 0.2 tA of the organic peroxide with respect to the α-olefin. Such organic peroxides preferably have a molecular weight of 200 or more. Specifically, tert-butylcumyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, 2゜5-dimethyl-2,5-di(t
These include ert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, α,α'-di(tert-butylperoxy)diisopropylbenzene, and the like.

The mixing ratio of the modified olefin polymer in the resin composition of the present invention is 1 to 150 parts by weight, preferably 5 to 100 parts by weight, based on 100 parts by weight of the aromatic polyester. If the amount added is 1 part by weight without grooves, the impact resistance improvement effect will be small, and if it exceeds 150 parts by weight, the heat resistance and bending strength, which are the inherent properties of aromatic polyester, will decrease. It is selected as appropriate depending on the purpose.

As a method for obtaining the composition of the present invention, a method of melt-mixing the aromatic polyester and the modified olefin polymer can be adopted, and it is preferable to use an extruder as the apparatus for melt-mixing.

It should be noted that fiber canes and granular fillers and reinforcing agents (for example, glass fibers, carbon fibers, metal fibers, potash titanate whiskers, glass peas, and glass flakes) may be added to the composition of the present invention within a range that does not impair the purpose of the present invention. , mica, asbestos, clay, talc, wollastenite, sericite, barium sulfate, calcium carbonate, etc.), antioxidants,
One or more conventional additives such as heat stabilizers, UV absorbers, lubricants, mold release agents, colorants including dyes and pigments, nucleating agents, etc. can be added.

The polyester resin composition of the present invention obtained by the above structure can be easily molded by ordinary methods such as injection molding and extrusion molding, and has improved impact resistance and toughness, so it can be used in electrical parts and automobiles. It can be used for parts, housing parts, tool storage boxes, power tool exterior parts, sporting goods, etc. (Examples) The present invention will be specifically explained below with reference to Examples.

Reference Example 1 5 parts by weight of allyl glycidyl ether and 0.2 parts by weight of di-tert-butyl peroxide were added to 100 parts by weight of Polybutene-1 (Polybutene-IM-11010 manufactured by Mitsui Petrochemical Industries [) 1] in a Henschel mixer in a nitrogen atmosphere. and mixed at room temperature. This mixture was melt-kneaded in a nitrogen atmosphere at 180°C for 10 minutes under high shear using a kneader, extruded, cooled, and pelletized to obtain modified polybutene-1(a).
I got it. After crushing this pellet, acetone/methanol =
Allyl glycidyl ether was extracted with 271 mixed solvent using a Soxhlet extractor, and the pellet was further dried and subjected to infrared spectroscopic analysis. Allyl glycidyl ether was found to be 1.
It was 9% by weight grafted.

Reference Examples 2 to 4 The grafting reaction of allyl glycidyl ether to unmodified polybutene-1 was carried out in the same manner as in Reference Example 1 except that the reaction temperature and reaction time were changed as shown in Table 1. (b) to (d) were obtained.

Reference Example 5 In the same manner as in Reference Example 1, a graft reaction of glycidyl methacrylate was carried out on unmodified polybutene-1 to obtain modified polybutene-1 (e). The results are shown in Table 1.

Table-1 Examples 1 to 5, Comparative Examples 1 to 5 Modified olefin polymers (a
) to (e) were uniformly mixed in the proportions shown in Table 2, and the mixture was melt-mixed using a 30 mm diameter twin screw extruder set at 265° C. and pelletized. Next, the pellets were dried with hot air at 140°C for an hour and molded using an injection molding machine set at 275°C at a mold temperature of 90°C. During molding, the lower limit pressure for molding, which is a guideline for moldability, was measured, and the degree of cracking was evaluated. Perform a tensile test according to
Physical properties were measured. The results are shown in Table 2.

Examples 6 and 7, Comparative Examples θ and 7 Glass fibers (3 stubble strands) and modified olefin polymers produced in the above reference examples are shown in Table 1. 3
The composition uniformly mixed in the proportion shown in was tested in the same manner as in Example 1, and the results are shown in Table 3.

(Effects of the Invention) As is clear from the results in Table 2.3, the polyester resin composition of the present invention produced by melt-mixing aromatic polyester and modified olefin polymer has good impact resistance and tensile strength. Since it has good moldability and provides excellent molded products, it will greatly contribute to industry.

Claims (1)

[Claims] A polyester resin composition comprising an aromatic polyester (A), an allyl compound having an epoxy group, and a modified olefin polymer (B) obtained from an α-olefin.