| abstract |
PROBLEM TO BE SOLVED: To produce a conjugated diene-based polymer having a narrow molecular weight distribution by selecting a specific polymerization temperature by a polymerization method exhibiting high initiator efficiency and promoting the reaction with high activity. SOLUTION: A transition metal compound having a cyclopentadienyl skeleton, which belongs to Group IV of the periodic table (A), and a co-catalyst (B) such as an organoaluminum oxy compound are contacted under the conditions satisfying the following formulas α and β. The conjugated diene monomer or the conjugated diene monomer and a monomer copolymerizable therewith are polymerized in the presence of the catalyst thus formed. Formula α: −100 <T <80 Formula β: 0.017 <t <6000exp (−0.0921T) Here, t is a contact time (minute), and T is a contact temperature (° C.). |