Method for producing graft copolymer rubber and polypropylene-based resin composition

摘要

A method for producing a graft copolymer rubber which comprises graft polymerizing an alkenyl aromatic compound to an ethylene- alpha -olefin-dicyclopentadiene terpolymer rubber having a Q value of more than 5.0 and Mooney viscosity at 100 DEG C. of 70 or less, in an aqueous suspension in the presence of a free radical initiator and a dispersant, and a polypropylene-based resin composition comprising 5 to 40% by weight of said graft copolymer rubber and 60 to 95% by weight of a polypropylene-based resin(B) selected from the group consisting of a crystalline propylene homopolymer (i) having a Q value of 3.0 to 5.0, isotactic pentad fraction of 0.97 or more and intrinsic viscosity measured in tetralin solution at 135 DEG C. of 0.85 to 1.60 dl/g, a crystalline propylene-ethylene block copolymer (ii) composed of 60 to 95% by weight of apropylene homopolymer portion having a Q value of 3.0 to 5.0, isotactic pentad fraction of 0.97 or more and intrinsic viscosity measured in tetralin solution at 135 DEG C. of 0.85 to 1.60 dl/g and 5 to 40% by weight of a propylene-ethylene random copolymer portion having a Q value of 3.0 to 5.0 ethylene content of 25 to 55% by weight, and a mixture of (i) and (ii).