| 摘要 |
PURPOSE:To obtain a copper clad laminated sheet excellent in hygroscopicity and fire retardancy without generating environmental pollution by using a paper base material formed from a cellulose fiber and a phenol resin fiber by a papermaking method as a base material. CONSTITUTION:A paper base material is impregnated with a thermosetting resin such as a phenol resin or an imide resin containing no halogen element and the impregnated base material is dried to produce a prepreg. A predetermined number of prepregs and copper foils are superposed one upon another and pressed under heating to produce a metal foil clad laminated sheet. Herein, as the base material, a paper base material formed from a cellulose fiber consisting of cotton linter and wool pulp and a fiber composed of a phenol resin, a tung oil modified phenol resin and a xylene resin being fire-retardant resins by a papermaking method is used. The mixing ratio of the phenol resin fiber to the cellulose fiber is 10-400 pts.wt., pref., 100-200 pts.wt. per 100 pts.wt. of the cellulose fiber. |
