Composition of styrene resin, thermoplastic resin and rubber

In the invention wherein Components (A), (B) and (C) are preferred, and Component (D) is optional, the following represent suitable definitions:

Suitable examples of the rubber-like polymers in Group (I) are shown below.

(1) Polymers obtained by polymerizing one or more of vinyl monomers in the presence of polymers containing alkyl acrylate and / or alkyl methacrylate (hereinafter referred to as "alkyl-acrylates") as main component.

Polymers containing alkyl acrylates as the main component are polymers obtained by polymerizing 70% or more by weight of alkyl acrylates and 30% or less by weight of other vinyl monomers copolymerizable with the alkyl acrylates, such as methyl methacrylate, acrylonitrile, vinyl acetate and styrene. Polymers obtained by using a suitable amount of a polyfunctional monomers, e.g., divinylbenzene, ethylene dimethacrylate, triallyl cyanurate and triallyl isocyanurate as a cross-linking agent are also included in the above polymers.

A specific example of rubber-like

(Preparation of Polystyrene having Syndiotactic Configuration)

2 L (L=liter) of toluene as a solvent, and 5 mmol of tetraethoxytitanium and 500 mmol (as aluminum atom) of methylaluminoxane as catalyst components were placed in a reactor, and 15 L of styrene was introduced thereinto and polymerized for 4 hours at 50.degree. C.

After the completion of polymerization, the reaction product was washed with a mixture of hydrochloric acid and methanol to decompose and remove the catalyst components, and then dried to obtain 2.5 kg of a styrene polymer (polystyrene). The polymer was subjected to Soxhlet extraction using methyl ethyl ketone as a solvent to obtain 95% by weight of an extraction residue. The weight average molecular weight of the polymer was 800,000. A .sup.13 C-NMR analysis (solvent: 1,2-dichlorobenzene) showed an absorption at 145.35 ppm, ascribable to the syndiotactic configuration, and the syndiotacticity indicated in terms of racemi pentad as calculated from the peak area was

100 parts by weight of a mixture consisting of 66.7% by weight of the polystyrene having syndiotactic configuration as obtained in Reference Example 1, 28.6% by weight of linear low density polyethylene (trade name: Idemitsu Polyethylene L1014D, produced by Idemitsu Petrochemical Co., Ltd.) as a thermoplastic resin, and 4.7% by weight of a styrene-hydrogenated butadiene block copolymer (trade name: G1652. produced by Shell Chemical Co., Ltd.) were kneaded in a single-screw extruder having an inner diameter of 25 mm and injection molded by the use of a minimat molding machine to form a test piece, which was then measured for mechanical strength. The Vicat softening temperature was measures according to JIS-K7206. The results are shown in Table 1.