The random copolymer rubber which consists of with the - olefin of the constituent for the sponge rubber, and the weatherstrip sponge

摘要

PROBLEM TO BE SOLVED: To obtain a composition which can give a sponge improved in weather resistance, ozone resistance, thermal aging resistance, blooming resistance and flatting resistance by mixing a specified random copolymer rubber with a vulcanizing agent and a blowing agent. ;SOLUTION: Ethylene in an amount of 55-90mol% is copolymerized with 45-10mol% 3-20C α-olefin and a branched polyene compound represented by the formula (wherein n is 1-5; R¹ is a 1-5C alkyl; R² and R³ are each H or a 1-5C alkyl) at -50 to 100°C for 5min to 5hr under a pressure of 50kg/cm² or below in the presence of a Ziegler catalyst in a hydrocarbon solvent to obtain a random copolymer rubber (A) having an iodine value of 8-30 and an intrinsic viscosity of 0.5-5dl/g (in decalin at 135°C). The component A of 100 pts.wt. is mixed with 0.1-10 pts.wt. vulcanizing agent (B), 0.1-20 pts.wt. vulcanization accelerator (C) and 0.5-30 pts.wt. blowing agent (D).;COPYRIGHT: (C)1998,JPO