| 摘要 |
PURPOSE:To provide a rubber compsn. having excellent resistance to heat and cold, processability and vulcanization characteristics, by blending a specified ethylene/alpha-olefin copolymer rubber with an inorg. filler and naphthenic or paraffinic oil. CONSTITUTION:An ethylene/alpha-olefin copolymer rubber (A) composed of 30-60wt% ethylene and a 3-8 C olefin, which has a ratio of weight-average MW to number-average MW of not lower than 4, an intrinsic viscosity of 1.6-4.0dl/g as measured in xylene at 70 deg.C, a green strength index of not lower than 0.8, a breaking strength GM of GM>=1.3 G100 and elongation at break of 900% or about and wherein a difference between the ethylene content of its high-molecular component and the mean ethylene content is 10-30, is blended with an inorg. filler (B) and naphthenic or paraffinic oil (C) in a ratio of 1<=(B+C)/A<=2 and 1.5<=B/C<=4 to obtain a compsn. which has a roll processing index of not lower than 3.0 and gives a vulcanized product having a ratio of tensile strength at break to Mooney viscosity (121 deg.C) of unvalcanized rubber blend of 1.5-2.5.
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