ETHYLENE-ALPHA-OLEFIN COPOLYMER RUBBER, RUBBER COMPOSITION, AND METHOD FOR PRODUCING ETHYLENE-ALPHA-OLEFIN COPOLYMER RUBBER

摘要

An ethylene-α-olefin-based copolymer rubber which contains an ethylene unit and an α-olefin unit having from 3 to 20 carbon atoms, and satisfies the following requirements (a) and (b) is provided. Requirement (a): a content of the α-olefin unit is 50% by mass or more and 70% by mass or less when a sum of a content of the ethylene unit and the content of the α-olefin unit is taken as 100% by mass. Requirement (b): a product of monomer reactivity ratios which is a product of a reactivity ratio of ethylene and a reactivity ratio of an α-olefin is 0.70 or less and the product of monomer reactivity ratios is a value determined from a ¹³C-NMR spectrum.