| abstract |
A novel cycloolefin copolymer that can be employed in the production of molding with fewer defects, for example, fewer gel particles (fish eyes). There is provided a cycloolefin copolymer comprising 80 to 20 mol% of repeating units derived from an .alpha.-olefin monomer and 20 to 80 mol% of repeating units derived from at least one cycloolefin monomer selected from the group consisting of monomer of the general formula (I), monomer of the general formula (II), monomer of the general formula (III), monomer of the general formula (IV) and monomer of the general formula (V), wherein with respect to the repeating units derived from cycloolefin monomer, the proportion thereof being present in the form of dimer (Rd) is 50 mol% or below and the proportion thereof being present in the form of trimer (Rt) 5 mol% or above. |