Ethylene-1-butene random copolymer and polypropylene resin composition comprising the same

摘要

An ethylene-1-butene random copolymer consisting essentially of a structural unit derived from ethylene and a structural unit derived from 1-butene, in which (i) the (ethylene/1-butene) weight ratio of the structural unit derived from ethylene to the structural unit derived from 1-butene is in the range of 80/20 to 60/40; and (ii) the complex shear viscosity eta 1 measured at a temperature of 230 DEG C and a cone plate angular velocity of 0.1 (rad/sec) is 2,000 (Pa.s) or more and the value ( eta 1/ eta 2) obtained by dividing the above complex shear viscosity eta 1 by a complex shear viscosity eta 2 measured at the same temperature and a cone plate angular velocity of 100 (rad/sec) is 4 or more. There is also provided a polypropylene resin composition containing the novel ethylene-1-butene random copolymer and a polypropylene resin and optionally a hydrogenated diene polymer. The resin composition has excellent stiffness, heat resistance and impact resistance and can give injection molded products having a good appearance with low surface gloss and substantially no flow mark.