| 摘要 |
PROBLEM TO BE SOLVED: To obtain a prepreg without impairing a productivity at the time of manufacturing by impregnating a glass base material having a whiteness degree of a specific value or less with a resin having a whiteness degree of a specific value or less, drying it, setting the whiteness degree to the specific value or less, and forming it. SOLUTION: The prepreg is obtained by impregnating a glass base material having a whiteness degree a resin varnish having a whiteness degree of 60 or less, and then drying it. As the varnish to be impregnated into the base material, a resin varnish obtained by dissolving a thermosetting resin such as an epoxy resin, modified epoxy resin or the like in an organic solvent can be used, and a normal resin varnish without adding a black pigment or the like having a whiteness degree of 95 or less can be used. Here, if the whiteness degree exceeds the 95, there might not be possibly 30 or less of the whiteness degree of the prepreg. Accordingly, after the base material having the whiteness degree of 60 or less is impregnated with the varnish having the whiteness degree of 95 or less, it is dried to lower the whiteness degree to 30 or less. |
