| abstract |
PURPOSE:To obtain the titled rubber having excellent heat-resistance and uniform surface and resistant to bleeding and migration, by compounding an ethylene-propylene copolymer rubber with a hydrogenated liquid diene rubber, a foaming agent and a vulcanizing agent at specific ratios. CONSTITUTION:The objective rubber can be produced by compounding (A) 100pts.(wt.) of an ethylene-propylene copolymer rubber with (B) 3-40pts. of a hydrogenated rubber having an iodine value of 15-300 and obtained by hydrogenating a liquid diene rubber, preferably a liquid polyisoprene or a liquid isoprene-butadiene rubber containing >=55% isoprene unit, (C) 0.5-20pts. (based on 100pts. of A+B) of a foaming agent (e.g. ammonium carbonat) and (D) 0.1-10pts.of a vulcanizing agent (e.g. sulfur) and foaming the mixture rubber heating. The average molecular weight of the liquid diene rubber is preferably 6,000-100,000. USE:The obtained sponge rubber is applied to an automobile door, etc. |