| 摘要 |
PURPOSE: To obtain a molded ceiling material for automobile which can be recycled, is light in weight, and has a high rigidity by crosslinking a specified propylene resin, heating an obtained foaming sheet, and foaming it. CONSTITUTION: A foaming sheet forming composition contains a propylene resin, a glass fiber, a radical generating agent, a crosslinking assistant, and a foaming agent in specified proportions. The propylene resin consists of a propylene block copolymer which contains 1.5-9wt.% of ethylene/propylene copolymeric segment and 91-98.5wt.% of crystalline polypropylene segment wherein a limiting viscosity of the ethylene/propylene copolymeric segment measured in a decalin at 135 deg.C is 2-8dl/g and the ethylene content is 1.5-9mol%. The foaming sheet forming composition is molded into a sheet at a temperature where the foaming agent does not decompose. One face of an obtained foaming sheet is backed with a packing material, irradiated with electrolytic radiation, and the propylene resin is crosslinked. After it is heated and foamed, a skin material is laid on the foamed sheet before the foamed sheet is cooled and solidified, and press molding is performed. |
