PURPOSE: To provide a prepreg composed of a reinforcing fiber, UV-curable resin, UV-curing catalyst, and a pigment which changes its color with ultraviolet radiation, having a weatherable layer at one of the prepreg surfaces, and furnished with a film which is integrated with the resin after curing.
CONSTITUTION: 100pts.wt. of a UV-curable resin (epoxyacrylate resin) is diluted with styrene. 0.1W5pts.wt. of a UV-curing catalyst (e.g. diacetyl, benzophenone, etc.) and 0.001W1pt.wt. of a pigment which changes its color with ultraviolet radiation (e.g. methylene blue, duazine, etc.) are dissolved or dispersed in the above solution, and thereafter, an isocyanate is mixed and dissolved in the solution. A glass fiber substrate (chopped strand mat) is immersed in the above product without delay, and defoamed. As an alternative method, the impregnated glass fiber substrate is laminated with a liner film, pressed and defoamed with a roller, and left in an aluminum foil paper for a whole day and night to obtain the objective prepreg sheet.
HANIYUUDA TOSHIAKI
YAMADA KUNIYOSHI
SHIBATA JIYOUJI
