POLYPROPYLENE RESIN COMPOSITION

摘要

PURPOSE:To increase greatly low-temperature impact strength while retaining high rigidity by modifying a polypropylene resin compsn., by blending a polypropylene having a specified intrinsic viscosity and a rubbery material. CONSTITUTION:A polypropylene resin compsn. is obtd. by blending 50-90wt% component A and 50-10wt% component B. Component A is a propylene homopolymer (a) having an intrinsic viscosity of 0.8-3.0dl/g or a xylene- insoluble propylene/ethylene copolymer (b) having an intrinsic viscosity of 0.8-3.0dl/g. Component B is a rubbery material composed of an ethylene/ propylene rubber (c) and/or a xylene-soluble propylene/ethylene copolymer (d) and contg. at least 60wt% polymer having an intrinsic viscosity of 0.6-1.5 times that of component A. Component (b) is an insoluble part obtd. by extracting the propylene/ethylene copolymer with hot xylene at 140 deg.C, cooling the extract to 50 deg.C and further extracting it for 2hr. Component (d) is a soluble part obtd. by the above extraction.