FLEXIBLE POLYPROPYLENE EXCELLENT IN HEAT RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a flexible polypropylene having an improved heat resistance because a molded article composed of a high molecular weight atactic polypropylene produced by using a specific metallocene catalyst is excellent in recoverability of extension but has a large residual extension such as 44% and the high molecular weight atactic polypropylene has not a sufficient heat resistance to satisfy. SOLUTION: This high molecular weight atactic polypropylene produced by using a metallocene catalyst comprising a metallocene compound, an activating compound and if necessary an organic aluminum compound, has a type A durometer hardness of <=HAD 60 measured by a method based on JIS K7215 and the following relational expression between a storage elastic modulus (E'160) at 160 deg.C and a storage elastic modulus (E'25) at 25 deg.C. E'160/E'25>1×10-3.