MODIFIED PHENOLIC RESIN, METHOD FOR PRODUCING MODIFIED PHENOLIC RESIN, MODIFIED EPOXY RESIN, METHOD FOR PRODUCING MODIFIED EPOXY RESIN, CURABLE RESIN COMPOSITION, CURED PRODUCT OF SAME, AND PRINTED WIRING BOARD

摘要

Provided are a modified epoxy resin and a modified epoxy resin whose cured products exhibit good heat resistance and dielectric properties, methods for producing these, a curable resin composition, a cured product of the curable resin composition, and a printed wiring substrate. A modified phenolic resin comprises a phenolic resin structure (A), wherein at least one aromatic nucleus (a) in the phenolic resin structure (A) has, as a substituent, a structural segment (1) represented by structural formula (1) below:; ;In the formula, Ar each independently represent a phenyl group, a naphthyl group, or a structural segment having, on an aromatic nucleus of a phenyl or naphthyl group, at least one substituent selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, a phenyl group, and an aralkyl group.