Patent ID: 7723434

Claim:
An olefinic thermoplastic elastomer obtained by melting and kneading ingredients, the ingredients including: a graft copolymer composed of an olefin co-polymer segment formed from a nonpolar α-olefin monomer, and a vinyl polymer segment formed from vinyl monomers, the vinyl monomers including at least styrene and butyl acrylate, wherein the graft copolymer has a polyphase structure in which one of the olefin co-polymer segment and the vinyl polymer segment form a dispersed phase in the other with a particle size of 0.01 to 1 μm, wherein the olefin co-polymer segment is an ethylene-propylene block copolymer with ethylene content of 10 wt % or less; an acrylic rubber formed from a monomer mixture in which 10 to 90 wt % of methoxyethyl acrylate, 5 to 85 wt % of alkyl acrylate, 5 to 15 wt % of acrylonitrile, and 0.1 to 10 wt % of allyl methacrylate are contained as main ingredients; 0.01 to 10 wt % of a crosslinking agent with respect to the total amount of the graft copolymer and the acrylic rubber; and 0.01 to 10 wt % of a co-crosslinking agent with respect to the total amount of the graft copolymer and the acrylic rubber.