EPOXY RESIN, EPOXY RESIN COMPOSITION AND PHOTOSOLDER RESIST INK AND PRINTED WIRING BOARD AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain an epoxy resin excellent in long-term preservability, good in the finger touch dryability of the coating film thereof after precured, and useful for photosolder resist ink excellent in resolution and sensitivity, by chain extension of a novolak-type epoxy resin with a specific compound. SOLUTION: This epoxy resin is obtained by chain extension of (A) a novolak-type epoxy resin such as of phenol novolak type, cresol novolak type or bisphenol A novolak type by using (B) a compound bearing two or more isocyanate groups in the molecule such as tolylene diisocyanate, (hydrogenated) xylylene diisocyanate or isophorone diisocyanate; for example, by reaction of the component A with 0.1-10wt.%, based on the component A, of the component B in the presence or absence of a catalyst such as an organotin compound or tertiary amine at 20-120 deg.C.