| 摘要 |
The present invention provides a composition for a sealing material used for production of a sealing material composed of a rubber foam, wherein the sealing material has low density without decrease of water cut-off property and deterioration of cell breakage treatment property and is improved in adhesion property to the surface of the members to be sealed with following the shape of the surface. A composition for a sealing material which comprise a rubber component comprising copolymer rubbers of ethylene, ±-olefin having 3 or more carbon atoms and unconjugated diene, a vulcanizing agent and a blowing agent, wherein the copolymer rubber consists of copolymer rubber A and copolymer rubber B, the copolymer rubber A being derived from ethylene, ±-olefin having 3 or more carbon atoms and 3 to 5% by mass of unconjugated diene, and the copolymer rubber B being derived from ethylene, ±-olefin having 3 or more carbon atoms and 9 to 15% by mass unconjugated diene, and a mass ratio (copolymer rubber B/copolymer rubber A) of the copolymer rubber B to the copolymer A is in the range of 1/99 to 50/50, and a sealing material composed of a vulcanized foam of the composition. |
