POLYMERIZATION CATALYST FOR CONJUGATED DIENE POLYMER, PROCESS FOR PRODUCING CONJUGATED DIENE POLYMER WITH THE SAME, RUBBER COMPOSITION FOR TIRE, AND RUBBER COMPOSITION FOR GOLF BALL

摘要

[PROBLEMS] To provide a polymerization catalyst for conjugated diene polymers with which a conjugated diene polymer having a high cis-1,4 structure content can be produced and which less leaves an aluminum residue after polymerization and has high catalytic activity. [MEANS FOR SOLVING PROBLEMS] The polymerization catalyst for conjugated diene polymers is characterized by comprising (A) a yttrium compound, (B) an ionic compound comprising a non-coordinating anion and cation, and (C) an organometallic compound of an element selected from Groups 2, 12, and 13 of the Periodic Table.