Process for preparing foamed and crosslinked shaped articles having improved heat-sealability and foamable and crosslinkable polyethylene resin composition used therefor

A process for producing a foamed and cross-linked polyethylene resin shaped article having improved heat-sealability which comprises adding (b) a heat-decomposable blowing agent, (c) a silanol condensation catalyst and (d) an organic peroxide having a decomposition temperature the same as or similar to that of the heat-decomposable blowing agent (b) to (a) a silane-modified polyethylene resin, the amount of said organic peroxide (d) being at least 0.005 part by weight per 100 parts by weight of the silane-modified polyethylene resin (a);

• melt-kneading the resulting mixture at a temperature lower than the decomposition temperature of the heat-decomposable blowing agent (b);
• shaping the mixture;
• and heating the resulting foamble and cross-linkable shaped article to the decomposition temperature of the heat-decomposable blowing agent or to a higher temperature thereby to foam and cross-link the silane-modified polyethylene resin.