| abstract |
[PROBLEMS] To provide a thermosetting resin composition having high withstand voltage insulation and excellent in heat resistance and storage stability. A) a cyanate ester compound having two or more cyanato groups in one molecule, (B) a phenol curing agent containing a resorcinol type phenol resin, (C) a tetraphenylborate salt of a tetra-substituted phosphonium compound, A thermosetting resin composition comprising at least one compound selected from tetraphenylborate salts represented by (2). (R 3 is selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a phenyl group, and n is an integer of 1 to 3) [Selection figure] None |