CATALYSTS FOR PREPARING CIS 1,4-POLYDIENES

摘要

A polymerization catalyst composition for preparing cis 1,4-polydienes is provided. The catalyst composition comprises (a) a metal-containing compound, said metal being a transition metal or a lanthanide metal; (b) a carbene, (c) an alkylating agent, and optionally (d) a halogen-containing compound with the proviso that the halogen-containing compound must be present when none of the metal-containing compound and the alkylating agent contain a labile halogen atom. Also provided is a process for producing a polydiene comprising reacting a conjugated diene in the presence of the polymerization catalyst composition.