| 摘要 |
PURPOSE:To provide a vulcanizable rubber compsn. having improved resistance to compression set, by blending a vulcanizing system with a nitrile group-contg. hydrocarbon rubber which has a lowered iodine value and the pH of a tetrahydrofuran soln. of which is adjusted to a specified value. CONSTITUTION:A nitrile group-contg. hydrocarbon rubber which has an iodine value of 120 or below and the tetrahydrofuran soln. of which has a pH of at least 5, is prepared by, e.g., hydrogenating part or the whole of the carbon-to- carbon double bond-contg. units of a nitrile group-contg. hydrocarbon rubber such as a butadiene/acrylonitrile copolymer rubber or an isoprene/acrylonitrile copolymer rubber and then treating it with an aq. alkaline soln. A vulcanizing agent such as sulfur or tetramethylthiuram disulfide, a vulcanizing aid such as zinc oxide or stearic acid, etc. are blended with the resulting rubber to obtain the desired vulcanizable rubber compsn.
|
