OLEFIN-BASED THERMOPLASTIC ELASTOMER

摘要

PROBLEM TO BE SOLVED: To provide an olefin-based thermoplastic elastomer having excellent balance of moldability and mechanical properties such as tensile properties and impact resistance. SOLUTION: This thermoplastic elastomer is composed of following components A and B and is obtained by dynamically heat-treating a composition produced by polymerizing the component B after a polymerization of the component A in the presence of an organic peroxide and making a gel fraction in the component B 5-70%. (A) A homopolymer of propylene having >=85% isotactic index or a copolymer component of propylene and a 2-8C otherα-olefin, in an amount of 30-70 wt.% based on whole of the composition. (B) A copolymer component comprising a copolymer of propylene and 2-8C otherα-olefins, containing propylene and ethylene as essential components and a content ofα-olefins other than propylene is 30-70 wt.%, in an amount of 70-30 wt.% based on whole of the composition.