JPS59197450A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide a thermoplastic resin compsn. having excellent gloss, resistance to weather and impact, etc., by treating a terpolymer composed of an ethylene/propylene rubber, an arom. vinyl compd. and a vinyl cyanide with a peroxide. CONSTITUTION:A graft terpolymer composed of an ethylene/propylene rubber, an arom. vinyl compd. (e.g. styrene) and a vinyl cyanide (e.g. acrylonitrile) or a thermoplastic resin composed of said terpolymer and an arom. vinyl/vinyl cyanide copolymer is prepd. This thermoplastic resin is treated with 0.05-3wt% peroxide to obtain the desired thermoplastic resin compsn. Examples of the peroxides are dicumyl peroxide, t-butyl peroxides, etc. The treatment is carried out, e.g., by kneading the resin and the peroxide in a Banbury mixer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin composition having excellent weather resistance, impact resistance, heat resistance and gloss. More specifically, 0.05 to 3% by weight of a ternary kraft copolymer consisting of ethylene propylene rubber, an aromatic vinyl compound, and a vinyl cyanide compound, or a thermoplastic resin consisting of this and the above-mentioned two types of vinyl compound copolymers. The present invention relates to a thermoplastic resin composition treated with a peroxide.

Focusing on the fact that ethylene propylene rubber has excellent weather resistance, efforts have been made to develop methods for graft copolymerizing ethylene propylene rubber with styrene and acrylonitrile to produce graft copolymers with excellent weather resistance and impact resistance. I've been exposed to it.

However, in order to improve impact resistance, measures such as increasing the rubber concentration have often been taken, but this has resulted in disadvantages such as a decrease in fluidity, heat resistance, and gloss.

The present inventors have arrived at the present invention as a result of intensive studies aimed at developing a thermoplastic resin composition that has excellent weather resistance, fluidity, gloss, and heat resistance. That is, the present invention uses a tertiary graft copolymer consisting of ethylene propylene rubber, an aromatic vinyl compound, and a vinyl cyanide compound, or a thermoplastic resin consisting of this and an aromatic vinyl compound-vinyl cyanide compound copolymer. .05~3
A thermoplastic resin composition treated with % by weight of peroxide, which is characterized by a good balance between weather resistance, impact resistance, gloss, heat resistance, and fluidity.

Treatment methods with peroxide include adding it dissolved in the monomer before the graft reaction, adding it in the granulation process after the graft reaction, or mixing it with the graft copolymer, aromatic vinyl compound, and cyanide vinyl compound copolymer. Add it when doing,
Regardless of the method described above, the process of chemorheologically modifying the thermoplastic resin by thermally decomposing the peroxide is carried out in a melt-mixed state of the resin using an extruder or a kneader such as a Banbury. The peroxide referred to is dicumyl peroxide, t
-butylcumyl peroxide, -butyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexane, 2,5-dimethyl-2,5-di-t-
These are organic peroxides such as butylperoxyhexine-3 and di-t-butylperoxydi-isoprobylbenzene.

The amount of peroxide added is 0.05 to 3% by weight based on the thermoplastic resin, but the optimum range is preferably 0.1 to 1% by weight. At less than 0.05% by weight, there is no effect on heat resistance and fluidity; on the other hand, at more than 3% by weight, fluidity greatly improves, but other physical properties (heat resistance, impact resistance, etc.) decrease. It is not appropriate to do so.

The ethylene propylene rubber referred to in the present invention is not only a two-component system (hereinafter referred to as EPM) consisting of ethylene and propylene, but also an eighth component, such as dicyclopentadiene, ethylythenenorbornene, 1,4-hexadiene, Ethylene propylene terpolymer (hereinafter referred to as EPDM) containing ゜5-hexadiene, 2-methyl-1,5-hexadiene, 1,4-cyclopentadiene, 1゜5-cyclooctadiene, etc. and mixtures thereof.
It also includes.

The molar ratio of ethylene to propylene in the ethylene propylene rubber is preferably in the range of 5:1 to 1:3.1. <
The proportion of unsaturated groups used in EPDM is preferably in the range of 4 to 50 in terms of iodine value. Also 2
It is also possible to use rubber seeds or more. For example, EPDM or EPM can be mixed with one or two types of polybutadiene, polyisoprene, Z-ethylene butadiene rubber, etc.
Friends of birch can also be used as rubber components. The blend between these different rubbers can be appropriately selected depending on the purpose. However, when weather resistance is the objective, the higher the proportion of ethylene propylene rubber in the rubber component, the better, for example, a range of 50 to 100% by weight is appropriate.

Examples of the aromatic vinyl compound include styrene, 2-methylstyrene, α-chlorostyrene, dimethylstyrene, and the like, with styrene being preferably used. In addition, as a vinyl cyanide compound,
1゛su'' etc. are used.

The weight ratio of the comb in the thermoplastic resin is 5 to 40% by weight.

The respective ratios of the aromatic vinyl compound and the vinyl cyanide compound in the tertiary graft copolymer and the binary graft copolymer are adjusted to a weight ratio of 2:1 to 5=1.

For example, in a copolymer system of styrene and acrylonitrile, 7
A weight ratio of 0/80 to 80/20 is optimal.

The graft copolymer and acrylonitrile styrene copolymer (A84i[&) used in the present invention are bulk polymerized,
It can be produced by emulsion polymerization, suspension polymerization, and solution polymerization.

A conventional radical polymerization catalyst is used as a catalyst for the graft reaction and the acrylonitrile/styrene copolymerization reaction. Peroxides such as benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, acetyl peroxide, tert-butyl peroxybenzoate, dicumyl peroxide, peroxybenzoic acid, peroxyacetic acid, tert-phthylberoxy, bivalate, etc. , azoisobutyronitrile and the like are suitable.

The purpose of the present invention will not be impaired by either 1) a one-stage graft reaction method or 2) a dilution method of an As resin containing a high rubber content graft as a method for obtaining the desired thermoplastic resin.

Example 1 A 1.Ot separable flask equipped with a Dimroth condenser, a thermometer, a glass tube for bubbling, a Hopkins condenser, and a stirring bar with three turbine-type stirring blades attached had an iodine value of 9.3.
, Mooney viscosity 57, propylene content 41% by weight, EPDM containing ethylidene norhorne as diene component
645f/1n-hexane 3,60Of and 18
After 00f of styrene was charged and sufficiently dissolved, 48g of benzoyl peroxide diluted with 600y of acrylonitrile and 24001 of ethylene chloride was added, and the mixture was stirred at 67°C in an argon gas atmosphere at a stirring speed of 600 rpm. Polymerize for 10 hours. After the reaction was completed, the graft polymerization solution was separated by precipitation in 251 methanol and dried under reduced pressure at 50°C for 20 hours and at 150°C for 3 hours, resulting in a rubber content of 27.
A graft copolymer of 8% by weight was obtained.

To 100 parts by weight of the obtained copolymer, 0.2x parts of 2,5-dimethyl-2,5-di and monobutylperoxyhexane were added, and the mixture was mixed in an OOC type Banbury mixer (Kobe Steel) 200'c. After stirring for 5 minutes, the mixture was extruded with a roll to form pellets. As a comparative example, the same treatment was performed in the absence of peroxide.

The basic physical properties of both pellets were measured according to the specified JIS method, and the following results were obtained. In addition, fluidity was measured using a Koka type flow tester (Shimadzu Corporation) at a load of 30K.
y, the flow rate per unit time at a temperature of 230″C.

*1 Test method: Based on JIS-'711B*
2 //: Compliant with JIS-7203*
3 tt: Compliant with JIS-7110 *4
//: Compliant with JIS-7207 *5 /
/: Example based on JIS-Z 874 A thermoplastic resin obtained by graft copolymerizing acrylonitrile and styrene to the same EPDM as in Example 1 (EPDM content 5 content 56 parts by weight, acrylonitrile styrene After mixing 85 parts by weight of a copolymer (manufactured by Taisel Chemical Industries, Ltd., Sehian N050) and 0.1 part by weight of di-t-butylperoxydi-isoprobyl benzene, the mixture was kneaded in a Banbury mixer to form a thermoplastic resin composition. As a comparative example, pellets were obtained in the same manner as described above in the absence of peroxide.Each basic physical property was measured using the measurement method described in Example 1, and the following results were obtained. The test method was the same as in Example 1.

Claims (1)

[Claims] 0.05 to 3% by weight of a ternary graft copolymer consisting of ethylene propylene comb, an aromatic vinyl compound, and a vinyl cyanide compound, or a thermoplastic resin consisting of this and an aromatic vinyl-vinyl cyanide compound copolymer. A thermoplastic resin composition treated with a peroxide.