Branched conjugated diene copolymer, rubber composition and pneumatic tire

摘要

The present invention relates to a branched conjugated diene copolymer which is useful for preparing a rubber composition, having high uniformity of a temperature dependence curve of a viscoelasticity tan δ, for a tire, a rubber composition comprising the copolymer, and a pneumatic tire produced using the rubber composition for a tire. The branched conjugated diene copolymer is composed of monomer components comprising a branched conjugated diene compound represented by a general formula (1):;
wherein R1 represents an aliphatic hydrocarbon group having 6 to 11 carbon atoms, and an aromatic vinyl compound represented by a general formula (2):
;
wherein R2 represents an aromatic hydrocarbon group having 6 to 10 carbon atoms, and R5 represents a hydrogen atom or the like, and a copolymerization ratio (m) of the aromatic vinyl compound (2) is 45% by mass or more.

主权项

1. A branched conjugated diene copolymer composed of monomer components comprising a branched conjugated diene compound represented by a general formula (1): wherein R1 represents an aliphatic hydrocarbon group having 6 to 11 carbon atoms, and an aromatic vinyl compound represented by a general formula (2): wherein R2 represents an aromatic hydrocarbon group having 6 to 10 carbon atoms, and R5 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, wherein a copolymerization ratio (m) of the aromatic vinyl compound (2) is 45% to 60% by mass, and wherein the branched conjugated diene copolymer has a weight-average molecular weight 500000 or more.