Patent ID: 7700698

Claim:
A process of producing a ring-opening metathesis polymer, which comprises subjecting, in the presence of a ruthenium carbene complex, at least one kind of cyclic olefin selected from a cyclic monoolefin represented by the following formula (1): wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are each a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group, a hydroxyl group, an alkoxy group, a carbonyl group, an ester group or a carboxyl group or a salt thereof, wherein any plural members thereof optionally form a cyclic structure together with carbon atoms bonded thereto, and m and n are each an integer of 0 to 4, wherein the total number of m and n is not less than 3, and a cyclic diolefin represented by the following formula (2): wherein R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 and R 18 are each a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group, a hydroxyl group, an alkoxy group, a carbonyl group, an ester group or a carboxyl group or a salt thereof, wherein any plural members thereof optionally form a cyclic structure together with carbon atoms bonded thereto, and p and q are each an integer of 0 to 4, wherein the total number of p and q is not less than 3, to a ring-opening metathesis polymerization reaction, wherein a treatment to decrease the amount of oxygen and/or peroxide in at least one kind of polymerization starting material which comprises the cyclic olefin is performed by adding an antioxidant and stirring at a temperature of 40 to 80° C. before the ring-opening metathesis polymerization reaction.