PURPOSE: To obtain the title rubber having excellent dynamic fatigue resistance and excellent conductivity by vulcanizing a rubber composition prepared by adding a conductivity improver to a specified copolymer comprising a higher α-olefin, an aromatic-ring-containing vinyl monomer and a nonconjugated diene.
CONSTITUTION: 5-200 pts.wt. conductivity improver (e.g. carbon black) is added to 100 pts.wt. copolymer rubber comprising a 6-20C higher α-olefin, an aromatic- ring-containing vinyl monomer of formula I wherein n is an integer of 0-5; R1 to R3 are each H or 1-8C alkyl and a nonconjugated diene of formula II wherein n is an integer of 1-5; R4 is 1-4C alkyl; and R5 and R6 are each H or 1-8C alkyl, provided that they are not simultaneously H atoms and having a molar ratio of the higher α-olefin to the aromatic-ring-containing vinyl monomer of 95/5 to 30/70, a nonconjugated diene content of 0.01-30mol%, and an intrinsic viscosity of 1.0-10dl/g as measured in decalin at 135°C, and the obtained mixture is vulcanized.
UCHIUMI AKIYOSHI
TOJO TETSUO
KAWASAKI MASAAKI
