| abstract |
A copolymer capable of improving the dispersibility of fillers such as carbon black and silica when used in a part of a rubber composition, and containing the copolymer, is blended, molded or added. Provided are a rubber composition having good rolling workability, excellent rolling resistance performance and wear resistance, and capable of suppressing a decrease in mechanical strength, and a tire using the rubber composition. . A copolymer containing a monomer unit (a) derived from a conjugated diene having 12 or less carbon atoms and a monomer unit (b) derived from farnesene. A method for producing the copolymer comprising copolymerizing at least a conjugated diene having 12 or less carbon atoms and farnesene. A rubber composition containing the copolymer (A), a rubber component (B), and carbon black (C). A rubber composition comprising the copolymer (A), a rubber component (B) and silica (D). A rubber composition comprising the copolymer (A), a rubber component (B), carbon black (C) and silica (D). A tire using at least a part of the rubber composition. [Selection figure] None |