| abstract |
A polyamine-vulcanizable highly saturated nitrile rubber composition having: an α,β-ethylenically unsaturated nitrile monomer unit; a diene monomer unit; an α,β-ethylenically unsaturated dicarboxylic acid monoester monomer unit; and an α,β-ethylenically unsaturated carboxylic ester monomer unit other than that mentioned previously. The polyamine-vulcanizable highly saturated nitrile rubber composition has superior low-temperature resistance in the presence of a polycyclic aromatic compound, and is formed by blending 4–31 parts by weight of an aliphatic carboxylic acid diester of a polyalkylene glycol with 100 parts by weight of a polyamine-vulcanizable highly saturated nitrile rubber that has an iodine number of 120 or less and an α,β-ethylenically unsaturated nitrile monomer unit content of 21.0-23.0% by weight, preferably 21.0-22.5% by weight, more preferably 21.0-22.0% by weight. This polyamine-vulcanizable highly saturated nitrile rubber composition can be used as a vulcanizable molding material for a seal material that is suitable for use even in environments such as those in which the seal material is immersed in a fuel oil that contains a polycyclic aromatic compound. |