THERMOPLASTIC ELASTOMER COMPOSITIONS

摘要

A thermoplastic elastomer composition prepared by partially crosslinking a composition comprising the following components (A), (B), (C) and (D): (A) 10-40% by weight of an ethylene/.alpha.-olefin copolymer prepared by copolymerizing ethylene and an .alpha.olefin having 3 to 12 carbon atoms in the presence of a catalyst comprising a solid component and an organoaluminum compound which solid component contains at least magnesium and titanium,the ethylene/.alpha.-olefin copolymer having the following properties (I) to (IV): (I) Melt index 0.01-50 g/10 min (II) Density 0.860-0.910 g/cm3 (III) Maximum peak temperature as measured according to a not lower than 100.degree.C differential scanning calorimetry (DSC) (IV) Insolubles in boiling n-hexane not less than 10 wt.% (B) 15-35% by weight of a propylene polymer; (C) 10-40% by weight of an ethylene/.alpha.-olefin copolymer rubber; and (D) 10-40% by weight of an ethylene/unsaturated monocarboxylic acid ester copolymer in which the carboxylate unit content is 2-10 mol%. The thermoplastic elastomer composition according to the invention has superior fluidity and the articles molded from such a composition have a superior appearance. The composition is particularly useful in the automotive and electric appliances industries.