| abstract |
PCT No. PCT/JP96/01865 Sec. 371 Date Jan. 2, 1998 Sec. 102(e) Date Jan. 2, 1998 PCT Filed Jul. 5, 1996 PCT Pub. No. WO97/02316 PCT Pub. Date Jan. 23, 1997A vulcanizable rubber composition comprising a blend which is prepared by micro-dispersing a polyolefin resin (B) in an ethylene- alpha -olefin-nonconjugated polyene copolymer rubber (A) comprising ethylene, a C3-C20 alpha -olefin and a nonconjugated polyene in a molten state and in which the mean diameter of dispersed particles of the polyolefin resin (B) is 2 mu m or below and the (B) to (A) weight ratio ranges from 5/95 to 50/50. The micro-dispersion of a polyolefin resin (B) can easily be attained by kneading the components (A) and (B) together with compounding ingredients (such as reinforcement, filler, softener, vulcanization accelerator, vulcanizing agent and so on) in a rubber kneader, through the resin (B) is essentially difficult of micro-dispersion. Further, the composition enables the provision of rubber articles having a high and constant quality at a low cost, because the resin (B) can well be dispersed by conventional rubber kneaders in a short time without fail. The process for producing the above composition comprises introducing a rubber mixture (E) comprising 100 parts by weight of the copolymer rubber (B) and 3 to 10 parts by weight of an organic solvent (D) into a multi-stage vented extruder through a feed port, while introducing a polyolefin resin (B) thereinto in an inert gas atmosphere through another feed port, kneading the rubber mixture (E) and the polyolefin resin (B) with the removal of the solvent. This process can easily give nonblocking vulcanizable pellets of an ethylenic copolymer rubber composition comprising an ethylene- alpha -olefin-nonconjugated polyene copolymer rubber (A) and a polyolefin resin (B) wherein the resin (B) is micro-dispersed in a good state. |