Cycloolefin polymer composition

摘要

There is provided a cycloolefin polymer composition comprising 8 to 40% by weight of a cycloolefin polymer [A] and 92 to 60% by weight of a cycloolefin polymer [B], both having specific properties, wherein a difference DELTA nD=|nD(A)-nD(B)| between the refractive index nD(A) of the polymer [A] and the refractive index nD(B) of the polymer [B] is not more than 0.015. This composition is excellent in impact resistance, transparency and heat resistance, and has a good balance of these properties. There is also provided a cycloolefin copolymer composition comprising 8 to 40% by weight of a cycloolefin elastomer component [Aa] of an alpha -olefin, a specific cycloolefin and a non-conjugated diene which contains a polymerizable carbon-carbon double bond; and 92 to 60% by weight of a cycloolefin copolymer component [Ba] which is obtained by copolymerizing an alpha -olefin and a specific cycloolefin in the presence of the elastomer component [Aa]; wherein a difference DELTA nD=|nD(A)-nD(B)| between the refractive index nD(Aa) of the component [Aa] and the refractive index nD(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 tranding off its transparency. There is also provided a cycloolefin copolymer composition comprising 8 to 40% by weight of a cycloolefin elastomer component [A alpha ] of an alpha -olefin and a specific cycloolefin which substantially contains no polymerizable carbon-carbon double bond; and 92 to 60% by weight of a cycloolefin copolymer component [B alpha ] which is obtained by copolymerizing an alpha -olefin and a specific cycloolefin in the presence of the elastomer component [A alpha ]; wherein a difference DELTA nD=|nD(A)-nD(B)| between the refractive index nD(A alpha ) of the component [A alpha ] and the refractive index nD(B alpha ) of the component [B alpha ] is not more than 0.015. This composition has also excellent properties inherent in a cycloolefin random copolymer and is improved particularly in impact resistance without trading off its transparency.