| 摘要 |
PROBLEM TO BE SOLVED: To produce a polyolefin resin crosslinked foamed body having excellent heat size-stability and homogeneous in crosslinking and good in extendibility. SOLUTION: An olefinic resin, an alkylalkoxysilane having two alkoxyl groups and a melting point of >=160 deg.C and a heat decomposition-type foaming agent are mixed as essential components. The obtained mixed raw material is molded at a temperature below the decomposition temperature of the foaming agent into a desired shape, and the molded material is irradiated with ionizing radiation to crosslink the polyolefin resin and, at the same time, to graft the alkylalkoxysilane to the polyolefinic resin. Subsequently, the product is made to foam by heating at a temperature same as or above the decomposition temperature of the foaming agent. Alternatively, the alkylalkoxysilane is grafted to the polyolefinic resin in advance. The grafted material is molded into a desired shape at a temperature below the decomposition temperature of the foaming agent and irradiated with ionizing radiation to crosslink of the grafted polyolefinic resin followed by heat foaming. |
