PROPYLENE-ETHYLENE BLOCK COPOLYMER

摘要

PROBLEM TO BE SOLVED: To obtain a propylene-ethylene block copolymer having excellent balance between impact resistance strength and rigidity and improved surface hardness. SOLUTION: In this propylene-ethylene block copolymer, an elution peak temperature(Tp) obtained by a heating fractionation method of a cold xylene insoluble part and MFR satisfy the relation of the equation Tp>=119.49-0.2591×log MFR, and the ratio of the tanδarea (<=-30 deg.C) of the propylene-ethylene block copolymer to the weight fraction of its cold xylene soluble part satisfys the relation of (tanδarea/weight fraction of cold xylene soluble part) >=0.6.