Abstract: A method for producing a cyclic olefin-based copolymer including one or more repeating units derived from an olefin, one or more repeating units derived from a cyclic non-conjugated diene, and one or more repeating units derived from a cyclic olefin, a glass transition temperature of the copolymer being equal to or higher than 100° C., the method includes a step of copolymerizing an olefin, a cyclic non-conjugated diene, and a cyclic olefin in a presence of a catalyst containing a transition metal compound and a compound, the transition metal compound contains one or two or more selected from the group consisting of a transition metal compound and a transition metal compound, and the compound contains one or two or more selected from the group consisting of an organic metal compound, an organic aluminum oxy compound, and a compound that reacts with the transition metal compound to form an ion pair.

Abstract: A method for producing a varnish-like cyclic olefin-based copolymer composition including a cyclic olefin-based copolymer and an organic solvent, the cyclic olefin-based copolymer including one or more repeating units derived from an olefin, one or more repeating units derived from a cyclic non-conjugated diene, and one or more repeating units derived from a cyclic olefin, the method includes a step of copolymerizing an olefin, a cyclic non-conjugated diene, and a cyclic olefin in a presence of a catalyst containing a transition metal compound and a compound, the transition metal compound contains one or two or more selected from the group consisting of a transition metal compound and a transition metal compound, and the compound contains one or two or more selected from the group consisting of an organic metal compound, an organic aluminum oxy compound, and a compound that reacts with the transition metal compound to form an ion pair.

Abstract: A cyclic olefin-based resin composition contains a cyclic olefin-based copolymer (A), an azo compound (B) which has an azo group in a molecule and includes no heteroatom other than a nitrogen atom constituting the azo group, and a hindered phenol compound (C), in which an iodine value of the cyclic olefin-based copolymer (A) is in a range of equal to or more than 20 g/100 g and equal to or less than 120 g/100 g, and a number-average molecular weight Mn of the cyclic olefin-based copolymer (A) is in a range of equal to or more than 3,000 and equal to or less than 30,000.

Abstract: A cyclic olefin-based copolymer including: (A) structural units (A) derived from one or more olefins represented by General Formula (I), (B) structural units (B) derived from one or more cyclic non-conjugated dienes represented by General Formula (II), and (C) structural units (C) derived from one or more cyclic olefins represented by General Formula (III).