RUBBER COMPOSITION AND USE THEREOF

摘要

A rubber composition capable of giving a molded object which is excellent in sealing properties, heat resistance, and acid resistance, has a low reaction force and low hardness, is reduced in compression set, and is especially improved in compression set and unsusceptibility to compressive cracking at high temperatures. Also provided are a use of the rubber composition and a main body including the rubber composition mounted thereon. The rubber composition is characterized by comprising a specific ethylene/a-olefin/unconjugated polyene copolymer [A], carbon black [B], and surface-modified silica [C] which is obtained by subjecting precipitated silica to surface modification and has a BET specific surface area of 30-80 m2/g, a particle diameter as measured by the Coulter counter method of 1.0-4.0 µm, and an M value of 50 or higher.