| 摘要 |
PURPOSE:To obtain the subject foamed article having excellent mechanical properties and useful as a heat-insulation material, etc., by forming a polyolefin containing a foaming agent in the form of a sheet, crosslinking with ionizing radiation, laminating the crosslinked sheets, heating for a prescribed period under pressure and removing the pressure to cause the expansion of the laminate. CONSTITUTION:The objective foamed article is produce by kneading 100 pts.wt. of a polyolefin (e.g. polyethylene) with preferably 3-30 pts.wt. of a foaming agent (having a decomposition temperature of preferably 180-270 deg.C; e.g. azodicarbonamide) and, as necessary, 0.05-5.0 pts.wt. of a crosslinking assistant (e.g. diallyl phthalate), forming the composition in the form of a sheet, crosslinking with preferably 0.1-50Mrad of ionizing radiation (e.g. alpha-ray), laminating the crosslinked sheets, heating under pressure at a temperature above the decomposition temperature of the foaming agent for a prescribed period and removing the pressure to effect the expansion of the laminate. |
