| 摘要 |
PROBLEM TO BE SOLVED: To provide olefinic thermoplastic elastomers excellent in the balance of flexibility and tensile elongation at break and low temperature impact resistance, and a method for preparing the same. SOLUTION: Olefinic thermoplastic elastomers comprise a composition which is composed of (A) 10-50 wt.%, based on the entire composition, propylene homopolymer or copolymer component of propylene and other 2-8Cα-olefins which has an isotacticity of not less than 85% and (B) 50-90 wt.%, based on the entire composition, copolymer component having, as the essential components, propylene and ethylene and composed of propylene and other 2-8Cα-olefins with a xylene isolubles content at room temperature of from not less than 5 wt.% to less than 10 wt.%, based on the entire composition, a xylene soluble matter content at room temperature of from more than 40 wt.% to not more than 85 wt.%, based on the entire composition, and a content of theα-olefins other than propylene in the xylene soluble matter content at room temperature of not less than 40% and is prepared by the polymerization of component (B) after the polymerization of component (A).
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