Acrylic copolymer and rubber material

An acrylic copolymer consisting of;

• (a) a structural unit (A) derived from a monomer containing a structure having an N-substituted maleimide represented by the following general formula (I),
• (b) a structural unit (B) derived from a (meth)acrylic acid alkyl ester and/or a structural unit (B) derived from a (meth)acrylic acid alkoxyalkyl ester, and
• (c) a structural unit (C) derived from an unsaturated monomer having a crosslinking group:
• wherein R is either an optionally substituted anilino group (C6H5—NH—) or a hydroxyl group,
• wherein the content of the structural unit (A) is from 0.1 to 2.5% by mass,
• wherein the content of the structural unit (B) is from 87.5% to 99.8% by mass,
• wherein the content of the structural unit (C) is from 0.1 to 10% by mass, and
• wherein the acrylic copolymer has a viscosity of 10 to 100 in terms of Mooney viscosity (ML1+4) at 100° C. in the Mooney scorch test as defined in JIS K 6300.