| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a laminated sheet which is free from the undermining of punchability and cost increase and shows outstanding resistance to impact by arranging one reticulated sheet base material between copper foil and a paper base material prepreg, when a specified number of impregnated sheets are superposed over each other and thermally molded under pressure into the laminated sheet. SOLUTION: A heat-curable resin of a phenol resin obtained by causing a chemical reaction between phenols such as phenol and cresol and formaldehyde, is dissolved in a solvent and then a paper base material is impregnated with varnish adjusted to the appropriate concentration and viscosity and dried to obtain a paper base material prepreg. Further, a required number of the paper base material prepregs are superposed over each other, and one sheet or more of a reticulated sheet base material are arranged between copper foil and the paper base material prepreg. After that, the laminate is thermally molded under pressure according to routine conditions to obtain a heat-curable resin. The reticulated sheet base material is made up of a sheetlike fiber material, e.g. an organic natural fiber such as cotton or a synthetic fiber such as a polyester fiber and is a reticulated woven material.</p> |
