Patent ID: 7105608

Claim:
A process for preparing a copolymer of propylene with a conjugated diene, having a carbon-carbon double bond in a side chain and a number average molecular weight of from 1,000 to 1,000,000, characterized in that propylene and the conjugated diene are copolymerized in the presence of hydrogen, a cross-linked metallocene compound represented by the following general formula (1), and at least one Lewis acid, and that the copolymer contains no 1,4-adduct derived from the conjugated diene, wherein R 1 and R 4 are each independently selected from the group consisting of a hydrogen atom and aryl groups having 6 to 20 carbon atoms, R 2 and R 3 are each independently selected from the group consisting of a hydrogen atom and alkyl groups having 1 to 5 carbon atoms, provided that not all of R 1 , R 2, R 3 , and R 4 are a hydrogen atom, M represents a transition metal of the group 4 of the periodic table, the two X's are each independently selected from the group consisting of a halogen atom and alkyl groups having 1 to 3 carbon atoms, and Q represents a cross-linking group.