CYCLOOLEFIN POLYMER COMPOSITION

摘要

Disclosed is a cycloolefin copolymer composition comprising (A) 8 to 40% by weight of a cycloolefin elastomer component of an .alpha.-olefin, a specific cycloolefin and optionally a non-conjugated diene which contains a polymerizable carbon-carbon double bond; and (B) 92 to 60% by weight of a cycloolefin copolymer component which is obtained by copolymerizing an .alpha.-olefin and a specific cycloolefin in the presence of the elastomer component (A), wherein a difference .DELTA.n D = ¦n D(A) - n D(B)¦ between the refractive index n D(Aa) of the component ¢Aa! and the refractive index n D(Ba) of the component ¢Ba! is not more than 0.015. This composition has excellent properties inherent in a cycloolefin random copolymer and is improved especially in impact resistance without trading off its transparency.