摘要 |
PROBLEM TO BE SOLVED: To provide polybutadiene rubber improved in the balance, which is useful as a rubber material among processability, wear resistance and low loss properties and the processability, wear resistance and low loss properties of which are improved and to provide a method for producing the polybutadiene rubber.SOLUTION: In a step of polymerizing 1,3-butadine in the presence of a transition metal polymerization catalyst to produce cis-1,4-polybutadiene, (A) an aromatic vinyl compound is added as an additive after the 1,3-butadine is polymerized and (B) a halogenated organic compound is added as another additive during the time when the aromatic vinyl compound exists. |