| abstract |
PROBLEM TO BE SOLVED: To provide an inexpensive, excellent co-vulcanizing and co-crosslinking property with a conjugated diene rubber and exhibiting excellent mechanical properties, fatigue resistance, ozone resistance, anti-vibration properties, etc. Provided are an environmentally friendly ethylene-based copolymer rubber, and a composition containing the copolymer rubber and a conjugated diene-based rubber. SOLUTION: The ethylene-based copolymer rubber comprises ethylene, α-olefin and 5-methyl-1,4 as constituent monomers. Containing hexadiene or further containing α, ω-diene, (1) ethylene / α-olefin molar ratio = 40 / (2) iodine value = 5-45, (3) Mooney viscosity = 15-350, (4) ratio of weight average molecular weight to number average molecular weight = 2.0-15, and (5) glass Transition temperature = -80 −−50 ° C. or (6) a branching degree index B = 0.60 to 0.95. The composition contains the ethylene copolymer rubber, the conjugated diene rubber, and a vulcanizing agent and / or a crosslinking agent. |