JPS6284149A - Glass fiber-reinforced polyester resin composition - Google Patents

Abstract

PURPOSE:To provide the titled lightweight composition of high performance in heat resistance, mechanical properties and low-temperature moldability, capable of giving molded articles of beautiful appearance, comprising PET, glass fiber, an unsaturated carboxylic acid (derivative)-modified polyolefin resin and ionomer. CONSTITUTION:The objective composition can be obtained by blending (A) 30-70wt% of PET with an intrinsic viscosity pref. >=0.5, (B) 5-45wt% of glass fiber 0.1-6mm long prepared pref. by surface treatment followed by bundling with epoxy resin, (C) 10-40wt% of (i) either a polyolefin resin (pref. polypropylene resin) modified with unsaturated acid or its derivative (pref. maleic anhydride, methyl acrylate) or (ii) a blend of said modified resin and unmodified one and (D) 0.5-10wt% of an ionomer prepared by acting a metal cation such as of Na or Zn on a base copolymer from ethylene and (meth)acrylic acid. followed by kneading.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a glass fiber-reinforced polyester resin composition, and more specifically, #thermal 1 has excellent mechanical properties, is lightweight, and has good moldability at low temperatures. The present invention relates to a glass fiber-reinforced polyester resin composition which has excellent properties, does not cause whitening and has a beautiful appearance, and is useful as a material for molded products in the automobile, electrical and electronic fields.

[Prior Art] In recent years, resin compositions reinforced with various reinforcing materials have been prized as engineering plastics. Among them, demand for compositions using glass fiber as a reinforcing material and polyester resin as a matrix is increasing because of its excellent heat resistance and mechanical strength properties.

[Problems to be Solved by the Invention] However, the glass fiber reinforced polyester resins known to date are not necessarily satisfactory in terms of heat resistance, mechanical strength, etc., and are also unsatisfactory in terms of moldability. However, there was a tendency for work stability to be lacking.

In order to solve these problems, the present inventors developed a resin composition comprising polyethylene terephthalate, glass fiber, polyolefin resin, and ionomer, and already filed a patent application on September 24, 1985.

This resin composition has excellent heat resistance, mechanical strength properties, and low-temperature mold moldability. However, the surface of the molded product tends to whiten a little, and improvement of this problem remains an issue.

The present invention is an improved product of the resin composition of the above application, which solves the above-mentioned problems and provides a glass fiber reinforced polyester resin which does not cause whitening of the surface, has excellent gloss, has a beautiful appearance, and is more practical. The purpose is to provide a composition.

[Means for Solving the Problems] As a result of extensive research in order to achieve the above object, the present inventors have found that a resin composition comprising a predetermined amount of the four components described below has a heat resistance of 1 mechanical strength. We discovered that the glass fiber-reinforced polyester resin composition of the present invention has excellent properties, is lightweight, has excellent moldability at low temperatures of 80 to 30°C, and has a beautiful appearance without whitening. I have come to develop it.

That is, the glass m-fiber reinforced polyester resin composition of the present invention contains 30 to 70% by weight of polyethylene terephthalate.
, 5 to 45% by weight of glass fiber, polyolefin resin modified with unsaturated carboxylic acid or its derivative 1
It is characterized by comprising 0 to 40% by weight and 0.5 to 10% by weight of an ionomer.

First, polyethylene terephthalate (
Hereinafter, it will be abbreviated as PET. ) is a linear polyester obtained by condensation polymerization of terephthalic acid or dialkyl terephthalate and ethylene glycol, which has terephthalic acid or dialkyl terephthalate and ethylene glycol as main components, and a copolymerizable third component is copolymerized with this. and a mixture of the linear polyester and the copolyester. Examples of the third component include isophthalic acid, naphthalene-2,6-dicarboxylic acid, adipic acid, diphenyl ether-4,4
- acid components such as dicarboxylic acids, sebacic acid, glycol compounds such as propylene glycol, neopentyl glycol, diethylene glycol, cyclohexane dimetatool, 2,2-bis(4-hydroxyphenyl)propane, p-oxybenzoic acid, Oxyacids such as p-hydroxyethoxybenzoic acid may be mentioned. Note that the PET is made of a mixed solvent of phenol/tetrachloroethane (
It is preferable that the intrinsic viscosity determined by measuring the solution at 30°C (1/1 weight ratio) is 0.5 or more, more preferably 0.
．． It is particularly preferable that it is 55 or more.

The amount of PET blended is set at 30 to 70% by weight based on the entire composition. If the blending amount is less than 30% by weight, the heat resistance of the resulting resin composition will decrease significantly, and
If the amount is more than % by weight, mold formability at low temperatures will be poor. Preferably it is 35 to 55% by weight.

Next, the glass fiber in the present invention can be any of alkali-containing glass, low-alkali glass, and alkali-free glass, and the length in this polyester resin composition is 0.02 to 2 mm, particularly preferably 0.05 to 1ffI11.

Since this glass fiber may be broken by the kneading machine when mixed with the PET, the length of the glass fiber when used for kneading is usually 0.1 to 1.
Preferably, it is 3a+m. Further, the diameter of such glass fibers is usually 1 to 20 mm. Further, the form of the glass fiber is not particularly limited, and may be, for example, roving, milled fiber, chopped strand, etc. Furthermore, the glass fiber may be subjected to surface treatment such as silane treatment, poran treatment, etc. It is preferable to use galan treatment, chromium treatment, etc. and then bundle the epoxy resin. After processing like this, PET
This is because the adhesion of the glass fibers is improved.

The blending amount of glass fiber is set at 5 to 45% by weight. If the amount is less than 5% by weight, the mechanical strength properties of the resulting resin composition will be significantly reduced, and if it is more than 45% by weight, the surface gloss of the resin composition will deteriorate and weight reduction will be inhibited. do. Preferably it is 15 to 35% by weight.

The modified polyolefin resin, which is the third component, means a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof, or a mixture of the modified polyolefin resin and an unmodified polyolefin resin. Examples of the polyolefin resin include propylene homopolymer, propylene homopolymer, block copolymer with other copolymer components such as ethylene.

Polypropylene resins such as random copolymers are preferred.

Unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid.

Crotonic acid, citraconic acid, sorbic acid, mesaconic acid,
Angelic acid, etc. Further, its derivatives include acid anhydrides, esters, amides, imides, metal salts, etc. Among these, acid anhydrides such as maleic anhydride, esters such as methyl acrylate; and amides such as acrylamide are preferred. .

Various known methods can be applied to modify polyolefin resins with these unsaturated carboxylic acids or derivatives thereof. For example, polyolefin resin and maleic anhydride can be modified by adding a radical initiator in the presence or absence of a solvent and heating the mixture. During this reaction, other vinyl monomers such as styrene, or rubbers such as liquid rubber and thermoplastic rubber may also be allowed to coexist.

The content of unsaturated carboxylic acid or its derivative in this modified polyolefin resin is 0.01 to 3.0% by weight.
It is preferable that If this content is less than 0.01% by weight, a whitening phenomenon will occur on the surface of the molded product of the obtained resin composition, and if it exceeds 3% by weight, it will result in a decrease in heat resistance or yellowing.

Particularly preferably 0.1 to 1.5% by weight.

The blending amount of this modified polyolefin resin is set at 10 to 40% by weight. - If the amount is less than 10% by weight, the moldability at low temperatures will be poor, and if it is more than 40% by weight, the heat resistance of the resin composition will be significantly reduced. Preferably it is 15 to 35% by weight.

The fourth component, the ionomer, is obtained by reacting metal cations such as sodium and zinc with a base copolymer of ethylene and methacrylic acid or acrylic acid. For example, Himilan 1707 (trade name, Mitsui DuPont Examples include those commercially available as Polychemical Co., Ltd.). Ml is 0.2 to log/10
min, t<d 0.5 to 3.0 g/10 min is suitable.

The blending amount of the ionomer is set at 0.5 to 10% by weight. If the amount is less than 0.5% by weight, the heat resistance of the resulting resin composition will decrease, and if it is more than 10% by weight, the heat resistance will decrease and the mold release may occur during mold molding at low temperatures. Sexuality becomes poor. Preferably it is 1 to 6% by weight.

The resin composition of the present invention can be prepared by kneading the above-mentioned four components in a conventional manner using a mixer such as a Panherly mixer, a Henschel mixer, an axle-shaft or a twin-screw pusher.

In addition, at this time, various antioxidants such as phenol type, phosphorus type, and sulfur type; various flame retardants such as halogen type, phosphorus type, and antimony type; various ultraviolet absorbers such as salicylic acid type, benzophenone type, and benzotriazole type; and nonionic type , anionic, cationic.

Various commonly used additives such as amphoteric antistatic agents; aliphatic hydrocarbons, higher aliphatic alcohols, fatty acid amide types, metal soaps, fatty acid ester type lubricants; mold release agents; color rejuvenating agents; nucleating agents; Can be blended.

[Examples of the invention] Examples 1 to 6, Comparative examples 1 to 10 Intrinsic viscosity measured by the method described above is O, 138 db/g
(A) Modified homopolypropylene with 6.6% by weight of maleic anhydride added (MI 250 g/10 min) and unmodified homopolypropylene (MI 250 g/10 min). Idemitsu Polypropylene J manufactured by Idemitsu Petrochemical @
-7000, MI 10g/10min, density 0.91g
/cm) to achieve the indicated maleic anhydride content, (B): Maleic anhydride addition amount 4.
0% by weight modified polyethylene (MI 0.3g/10
min) and unmodified polyethylene (Idemitsu Polyethylene 120 from Idemitsu Petrochemical Co., Ltd., XI 20g/10min, density 0.956g/fan) to give the indicated maleic anhydride content, MI 0.9g /10 minute ionomer (Himilan 1707 manufactured by DuPont Mitsui Polychemicals ■) was prepared, and these were blended at the indicated blending ratio (% by weight), R-kneaded, and pelletized. The resulting beret was molded by injection molding (mold temperature: 85°C).
) to mold test pieces, and the properties of these test pieces were measured based on the following specifications. The results are shown in the table.

Density: Compliant with JTSK7+12.

Izotsu impact strength: Compliant with JISK7110.

Heat distortion temperature: Based on JISK7207.

Appearance: Visual observation of the appearance of the test piece, - [Effects of the invention As is clear from the above explanation, the glass #a fiber reinforced polyester resin composition of the present invention has excellent heat resistance and mechanical strength characteristics, and is lightweight. Moreover, it has excellent moldability at low temperatures of 80 to 30°C, and the molded products do not whiten and have a beautiful appearance, making them suitable for injection molding and other molding processes in the automobile, electrical, and electronic fields. Its industrial value is great as a material for molding products.

Claims (1)

[Claims] 30-70% by weight of polyethylene terephthalate, 5-45% by weight of glass fibers, 10-40% of polyolefin resin modified with unsaturated carboxylic acid or its derivatives
% by weight and 0.5 to 10% by weight of an ionomer.