Cycloolefin type random copolymer compositions and uses thereof

A cycloolefin type random copolymer composition comprising (i) a cycloolefin type random copolymer containing a ethylene component, and a cycloolefin component represented by the following general formula [I] or [II] and having an intrinsic viscosity [.eta.] of 0.01-10 dl/g as measured at 135.degree. C. in decalin, and (ii) a phenolic antioxidant and (iii) fatty ester of polyhydric alcohol derived from esterification of a part of the alcoholic hydroxy groups of a polyhydric alcohol exhibiting a valence of at least 3. ##STR58## wherein n and m are each 0 or a positive integer, l is an integer of at least 3, and R.sup.1 to R.sup.10 each represent hydrogen atom, halogen atom or hydrocarbon group.

An information recording base board which has been molded from a cycloolefin type random copolymer composition comprising

• (A) cycloolefin type random copolymer containing an ethylene component, and a cycloolefin component represented by the following general formula [I] or [II] and having an intrinsic viscosity [.eta.] of 0.05-10 dl/g as measured at 135.degree. C. in decalin and a softening temperature (TMA) of not lower than 70.degree. C., and
• (B) a cycloolefin type random copolymer containing an ethylene component, and a cycloolefin component represented by the following general formula [I] or [II] and having an intrinsic viscosity [.eta.] of 0.01-5 dl/g as measured at 135.degree. C. in decalin and a softening temperature (TMA) of below 70.degree. C., the weight ratio of said (A) component/(B) component ranging from 100/0.1 to 100/10. ##STR59## wherein n and m are each 0 or a positive integer, l is an integer of at least 3, and R.sup.1 to R.sup.10 each represent hydrogen atom, halogen atom or hydrocarbon group.

An information recording base board which has been molded from a cycloolefin type random copolymer composition comprising (i) a cycloolefin type random copolymer containing an ethylene component, and a cycloolefin component represented by the following general formula [I] or [II] and having an intrinsic viscosity [.eta.] of 0.01-10 dl/g as measured at 135.degree. C. in decalin and (ii) a phenolic antioxidant and (iii) fatty ester of polyhydric alcohol derived from esterification of a part of the alcoholic hydroxy groups of a polyhydric alcohol exhibiting a valence of at least 3. ##STR60## wherein n and m are each 0 or a positive integer, l is an integer of at least 3, and R.sup.1 to R.sup.10 each represent hydrogen atom, halogen atom or hydrocarbon group.