Japan Synthetic Rubber Co., Ltd.

Shin-ichi Shimokawa

Yuji Yamamoto

Hisao Nagai

In a process for continuously producing an impact-resistant resin containing 5 to 30% by weight of a rubber by the solution-graft-polymerization of a monomer mixture of an aromatic vinyl compound and a vinyl cyanide compound in the presence of an ethylene-propylene-non-conjugated diene terpolymer rubber in an inert solvent comprising as essential component an aromatic hydrocarbon, two or more polymerizers connected in series are used; said rubber is fed to the first polymerizer in the form of a homogeneous solution in a part or whole of said monomers and/or said inert solvent, together with the remaining monomer or monomers and/or inert solvent; the rubber is kept in the dispersed state in the first polymerizer; said monomers are polymerized therein with stirring until the polymerization conversion reaches 40 to 80% by weight based on the monomers, and the remaining monomers are further polymerized with stirring in the second and succeeding polymerizers to substantially complete the polymerization. The resin prepared by the above improved method is excellent in gloss, hardness, chemical resistance and, in addition, in weather resistance and impact resistance.

Continuous multi-zone graft polymerization

A process for the preparation of a rubber-modified thermoplastic resin, which comprises treating an ethylene-propylene-non-conjugated diene copolymer rubber with a peroxide in a hydrocarbon or halogenated hydrocarbon solvent to obtain a rubber solution with a rubber gelation degree of not more than 5% and containing substantially no unreacted peroxide, adding to this rubber solution a vinyl monomer consisting of an aromatic alkenyl compound and a polar vinyl compound, and heating the resulting mixture to graft-copolymerize the monomer on the rubber. The resin obtained according to this process is free of fish eyes and proof against delamination of shaped article and has excellent mechanical properties, excellent appearance when shaped and high weather resistance.

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Yokkaichi, Japan

Shin-ichi Shimokawa