POLYPROPYLENE COMPOSITION

PURPOSE: To obtain a composition excellent in flexibility, impact resistance and heat resistance by mixing a polypropylene with a propylene-1-butene or -ethylene elastomer produced by using a specified metallocene compound catalyst. CONSTITUTION: This polypropylene composition comprises 5-95wt.% polypropylene A and 95-5wt.% base polypropylene elastomer B. Component B is an elastomer having a specified molecular structure in which the triad tacticity and stereoregularity of a propylene chain composed of head-to-tail bonds are high, and prepared by copolymerizing 50-95mol% propylene with 5-50mol% 1-butene or ethylene in the presence of a catalyst, e.g. a combination of a metallocene compound represented by the formula (wherein M is a group IVa, Va or VIa transition metal; R and R are each H, halogen, a hydrocarbon group or the like; R is a 3-20C alkyl or an aromatic group; R is H or a 1-20C alkyl; X and X are each H, a halogen, a 1-20C hydrocarbon or the like; and Y is a 1-20C hydrocarbon group or the like especially desirably an alkylsilylene or the like) with an organoaluminumoxy compound.