PHOSPHORUS-ATOM-CONTAINING OLIGOMER COMPOSITION, CURABLE RESIN COMPOSITION, SUBSTANCE RESULTING FROM CURING SAME, AND PRINTED CIRCUIT BOARD

摘要

The present invention dramatically improves the flame retardancy and heat tolerance of a cured substance, in addition to the solubility thereof in organic solvents. A phosphorus-atom-containing oligomer is used as an epoxy-resin hardener. Said oligomer is represented by structural formula (1) (in which R1 to R5 each independently represent a hydrogen atom, a C1-4 alkyl group, or the like; X represents a hydrogen atom or a structural unit represented by structural formula (x1); and in structural formula (x1), R2 to R5 each independently represent a hydrogen atom or a group such as a C1-4 alkoxy group) and is a mixture of phosphorous-atom-containing compounds with n in structural formula (1) being 0 and phosphorus-atom-containing oligomers with n in structural formula (1) being 1 or greater. Said phosphorus-atom-containing oligomers with n in structural formula (1) being 1 or greater constitute 5-90% of the total in terms of peak area as measured by GPC.