| 摘要 |
<p>PURPOSE:To enable the sufficient impregnation of a resin in a substrate, and to produce a prepreg for laminated sheet, having excellent water-absorption resistance and electrical insulation characteristics, by applying fine pores and fluffs to a sheet substrate, impregnating a resin to the substrate, and drying the resin. CONSTITUTION:A sheet substrate is introduced between a pair of rolls planted with 80 hooked noodles per 1cm<2>. The needle 2 is thrust through the substrate 1, and pulled from the substrate to effect the hooking and fluffing of the substrate fiber. A resin varnish is impregnated in the substrate, and dried at 160 deg.C for 5min to obtain the objective prepreg. The obtained prepreg has increased surface area by the fluffing treatment, and lowered apparent density of the substrate. The resin can be impregnated rapidly in the substrate, and a laminated sheet having excellent electrical insulation characteristics and moisture- absorption resistance can be produced.</p> |
