RESIN COMPOSITION, PREPREG, METAL FOIL WITH RESIN, METAL-CLAD LAMINATE, PRINTED WIRING BOARD

摘要

The present invention includes an epoxy resin and a curing agent including a first acid anhydride and a second acid anhydride. The unsaturated bond concentration, as represented by formula (1), for the second acid anhydride does not exceed 0.7%. The ratio of the number of acid anhydride equivalent in the first acid anhydride to the number of epoxy equivalent in the epoxy resin is greater than or equal to 0.05 and less than or equal to 0.5, and ratio of the sum of the number of acid anhydride equivalent of both the first and second acid anhydrides to the ratio of the number of epoxy equivalent is greater than or equal to 0.5, and less than or equal to 1.1. Unsaturated bond concentration = {(number of unsaturated bonds in a molecule/molecular weight)/number of acid anhydride groups in a molecule}x100…(1)