| 摘要 |
PURPOSE:To obtain a foam having excellent waterstopping property and durability and properly reduced restoring force, by molding a compd. consisting of a PVC resin, a natural or a synthetic rubber, an asphalt, a foaming agent and a crosslinking agent into a sheet and expanding it by heating. CONSTITUTION:A compd. is obtd. by compounding 100pts.wt. (hereinafter merely pts.) PVC resin (a), 10-100pts. natural or synthetic rubber (b) (e.g., nitrile- butadiene rubber), 10-150pts. asphalt (c) (e.g., a straight asphalt), a foaming agent (d) (e.g., azodicarbonamide) and a crosslinking agent (e) (e.g., dicumyl peroxide). Then, this compd. is kneaded, formed into a required sheet, and then expanded at 130-200 deg.C for 10-20min with an expansion ratio of 2-20. |
