CATALYST COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a polymerization catalyst for producing a polymer containing a high content of a cis 1,4-structure in its microstructure and having a narrow molecular weight distribution. SOLUTION: This catalyst composition for polymerizing a conjugated diene comprises (A) a metallocene complex of a rare-earth metal compound (e.g. a samarium complex or the like) and (B) an ionic compound consisting of a non-coordinating anion and a cation, e.g. triphenylcarbonium tetrakis(pentafluorophenyl)borate and/or aluminoxane.