| 摘要 |
PURPOSE:To obtain the titled foam having uniform, fine cells with an expansion ratio of 30 or below, by expanding an expandable polyolefin compsn. while avoiding its rapid expansion, and increasing the amount of carbon particles to be blended. CONSTITUTION:13-30pts.wt. carbon particles such as carbon black and appropriate amounts of a blowing agent and a crosslinking agent are kneaded with 100pts.wt. polyolefin to obtain a crosslinkable, expandable polyolefin resin compsn. having electrical conductivity. As a first method, the compsn. is heated under pressure for a given period of time and the pressure is reduced under high temp. to obtain the titled foam. A second method consists of two stages wherein the compsn. is heated in the first stage under pressure for a given period of time whereby 15-85% of the blowing agent is decomposed to form an intermediate primary foam and the primary foam is heated in the second stage under atmospheric pressure to decompose the residual undercomposed blowing agent. |
