| 摘要 |
PROBLEM TO BE SOLVED: To obtain a prepreg which can stably give a laminate excellent in humidity resistance and heat resistance by mixing a bisphenol S epoxy resin in a state heated to a specified temperature with a bisphenol A epoxy resin and a curing agent and impregnating a base with the obtained resin composition. SOLUTION: The bisphenol S epoxy resin desirably having an epoxy equivalent of about 100-600 and being in a state heated to 70-90 deg.C is mixed with the bisphenol A epoxy resin desirably having an epoxy equivalent of about 100-800 and a curing agent being desirably dicyandiamide, and a base (e.g. glass cloth) is impregnated with the obtained resin composition, It is desirable that the bisphenol S epoxy resin is used in an amount of 5-15 pts.wt. (in terms of the solid matter), per 100 pts.wt. solids of the epoxy resin composition. As a result, it seldom occurs that the curing agent crystallizes and precipitates during the storage of the epoxy resin composition, and the obtained laminate resists to deterioration in humidity resistance and heat resistance. |
