| 摘要 |
<p>PURPOSE:To make water resistance/moisture resistance favorable, by a method wherein a ratio of cure of melamine resin adhering to a base material is made into a specific one prior to impregnation of the same with unsaturated polyester resin. CONSTITUTION:Pretreatment is performed by impregnating a paper base material with an impregnating solution consisting mainly of melamine resin and drying the same, then the same is impregnated with unsaturated polyester resin, a plurality of sheets of resin impregnated base materials are laminated and cured after one side or both the sides of the same are plated with metallic foils at need. A ratio of cure of the melamine resin stuck to the paper base material is controlled to the utmost up to impregnation of the paper base material with the unsaturated polyester resin so that the same is made 50% of less, preferably 35% of less, further preferably 20% or less. A water absorption ratio/moisture alsorption ratio are decreased sharply like this and transparent feeling also becomes favorable.</p> |
