| abstract |
Provided is a nitrile group-containing copolymer rubber, which contains 10 to 30% by weight of α, β-ethylenically unsaturated nitrile monomer units, 1 to 10% by weight of fumaric acid monoester monomer units, and α, β-ethylene The unsaturated unsaturated monocarboxylic acid ester monomer unit is 1 to 50% by weight, and the iodine value is 120 or less. |