FIBER-REINFORCED EXPANDABLE COMPOSITE RESIN MATERIAL FOR MOLDING, PREMOLDED ITEM PRODUCED THEREFROM, AND MOLDING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To obtain a fiber-reinforced expandable composite resin material for molding which can be easily filled into the hollow section of a hollow structural member, has high rigidity and strengths, and is lightweight and excellent in energy absorption by compositing at least two thermoplastic resins and a fibrous reinforcement and by incorporating a blowing agent into the material. SOLUTION: This material is prepd. by incorporating 0.01-3 pts.wt. (based on the resin component described below) blowing agent into a fiber-reinforced composite resin contg. a thermoplastic resin component and 30-80wt.% fibrous reinforcement. The resin component comprises at least two thermoplastic resins and contains 1-50 wt.% thermoplastic resin having a melt viscosity of 10,000 cP or lower at 180 deg.C, and each resin contained in the component melts or softens at a temp. lower than the blowing temp. of the blowing agent. The fibrous reinforcement has a fiber lengths of 3-50mm and a fiber diameter of 5-20μm. This material is premolded at a temp. not higher than the blowing temp. of the blowing agent and then is heated to a temp. higher than the melting or softening point of the major thermoplastic resin but not higher by 50 deg.C to be expanded and molded.