PREPREG AND LAMINATED SHEET PREPARED BY USING RESIN COMPOSITION WITH LOW DIELECTRIC CONSTANT AND LOW DIELECTRIC DISSIPATION FACTOR

摘要

PROBLEM TO BE SOLVED: To obtain a prepreg consisting of a resin compsn. with excellent dielectric characteristics such as dielectric const. and dielectric dissipation factor and good heat resistance, mechanical processability and flame resistance. SOLUTION: This prepreg is prepd. by impregnating a base material with an epoxy resin compsn. consisting of an epoxy resin being at least one kind of epoxy resin contg. at least two epoxy groups in one molecule and further containing at least one brominated epoxy resin, an epoxy resin curing agent being a copolymer wherein styrene and maleic anhydride are essential components, a flexibilizer which can decrease the glass transition temp. of the compsn. by 10-20 deg.C by compounding it in the compsn., and a solvent with a b.p. of at least 100 deg.C being a solvent for these components as essential components. The mean bromination ratio in the whole epoxy resin is at least 30wt.% and the mean epoxy equivalent is at most 500 and the mean hydroxyl group concn. is at most 1×10<-3> mole/g.