| 摘要 |
A rubber composition by which a rubber elastic body having both of excellent low rolling resistance and wet skid resistance and also having excellent mechanical strength and wear resistance can be obtained, a rubber elastic body, a tire, and a block copolymer are provided. The rubber composition of the present invention comprises a block copolymer (A) comprising a block (a-1) of a conjugate diene and an aromatic vinyl and a block (a-2) of a conjugate diene or the diene and an aromatic vinyl, a specific polymer (B) other than the copolymer, and a filler (C), wherein the block copolymer (A) has a specific functional group; the block copolymer (A) has two glass transition temperatures separated from each other by 5°C or more within a range of -100 to 20°C in measurement in accordance with ASTM D3418; and the ratio of the block copolymer (A) is 10% by mass or more when the sum of the block copolymer (A) and the polymer (B) is taken as 100% by mass. |
