Sumitomo Chemical Company, Limited

Koichiro Ibuki

Tadashi Hikasa

Tatsuo Hamanaka

Motoo Mizumori

Masahiro Fukuyama

Akio Daimon

An olefinic resin composition which is moldable to shaped articles coatable with coating compositions without primers is prepared by blending (A) a cross-linked olefinic thermoplastic elastomer obtained from a homo- or co-polymer of alpha-olefin (C.sub.2-20) and elastomeric copolymer composed of alpha-olefins (C.sub.2-20), (B) a low-molecular weight modified polypropylene having Mn of 2,000-20,000 which is grafted with maleic anhydride and (C) a tackifier.

Olefin resin composition

A blend which comprises a partially crosslinked product of a mixture of an oil-extended olefinic copolymer rubber comprising an olefinic copolymer rubber having a 100.degree. C. Mooney viscosity 150-350, a polyolefin resin, a selectively hydrogenated block copolymer, and a specific mineral oil type softening agent has excellent flexibility of less than 45 in Shore A hardness. The blend is not tacky, nor does the softening agent bleed. An anti-static agent for polyolefins and/or a higher fatty acid amide may be included in the composition.

Thermoplastic elastomer composition which has a shore a hardness of less

An olefinic thermoplastic elastomer composition which is excellent in mechanical properties and is substitutable for vulcanized rubbers is provided, which comprises a mixture comprising (A) 40-95% by weight of an oil-extended olefinic copolymer rubber comprising 100 parts by weight of an olefinic copolymer rubber having a Mooney viscosity (ML.sub.1+4 100.degree. C.) of 150-350 and 20-150 parts byw eight of a mineral oil and (B) 5-60% by weight of an olefinic plastic, said mixture being partially crosslinked by dynamic heat treatment in the presence of an organic peroxide. This composition gives superior molded articles free from bleeding of oil on the surface.

Process for producing a thermoplastic elastomer composition

An olefinic thermoplastic elastomer composition which is excellent in mechanical properties and is substitutable for vulcanized rubbers is provided, which comprises a mixture comprising (A) 40-95 % by weight of an oil-extended olefinic copolymer rubber comprising 100 parts by weight of an olefinic copolymer rubber having a Mooney viscosity (ML.sub.1+4 100.degree. C.) of 150-350 and 20-150 parts by weight of a mineral oil and (B) 5-60% by weight of an olefinic plastic, said mixture being partially crosslinked by dynamic heat treatment in the presence of an organic peroxide. This composition gives superior molded articles free from bleeding of oil on the surface.

Olefinic thermoplastic elastomer composition

The present invention provides a thermoplastic elastomer composition excellent in oil resistance. This composition comprises a partially crosslinked mixture of (A) an ethylene copolymer rubber comprising ethylene and an acrylate ester or a methacrylate ester and (B) an olefin polymer and, if necessary, (C) an olefin copolymer rubber.

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Chiba, Japan

Koichiro Ibuki