| 摘要 |
PURPOSE:To obtain a paper substrate phenolic resin prepreg capable of equalizing the curing rates of the primary impregnated resin to each other, excellent in moisture resistance, and useful for laminates, etc., by treating a paper substrate with a melamine-modified phenolic resin solution adjusted to a prescribed pH and subsequently impregnating the treated product with a phenolic resin. CONSTITUTION:A paper substrate is treated with the solution of a melamine- modified phenolic resin, e.g. a resin produced by mixing a resol resin with a melamine resin obtained by reacting melamine with a formaldehyde compound, controlled to a pH of 6.5-7.5, and subsequently impregnated with a phenolic resin to provide the objective prepreg. The prescribed number of the prepregs are superposed on each other, and subsequently heated and pressed to provide the objective paper substrate phenolic resin laminate. |
