Ethylenic random copolymer, process for preparing the same, and rubber composition

摘要: A process for preparing an ethylene/α-olefin/norbornene nonconjugated polyene random copolymer, comprising ethylene copolymer simultaneously meeting the following requirements (1) to (5): molar ratio of (a) α-olefin (b) having 3 20 carbon atoms ranges from 40:60 95:5; (2) a given amount non conjugated (c) has norbornene skeleton; (3) available network chain density ξ is not less than 1.5 x 1020/cm3 after press cross-linking using dicumyl peroxyde; (4) rate η?1? shear showing shearing stress 0.4 10?6 dyn/cm2? as determined melt flow curve at 100 °C and η?2? 2.4 dyn/cm2?, that is, η?2?/η1 relationship represented by general formula: 0.04 10?-19? ≤ Log(η?2?/η1)/ξ 0.20 10?-19?; (5) intrinsic viscosity [θ] 0.5 10 dl/g measured in decalin 135 °C. The excellent cross-linkability, can be cross-linked with small peroxide or like, rubber composition prepared this heat aging resistance, mechanical strength, weather ozone resistance.