abstract |
Copolymer having polymer chain (A) having units derived from diene and / or olefin, polymer chain (B) having units derived from (meth) acrylic monomers and units having a ring structure in the main chain In the polymer chain (B), the content ratio of the unit derived from the (meth) acrylic acid ester is 45% by mass or more and 98% by mass or less. |