| abstract |
This invention provides a photosensitive resin composition comprising an acid group-containing vinyl ester resin and a photopolymerization initiator as indispensable components. The acid group-containing vinyl ester resin has a multiple branching molecular structure and is produced by reacting an epoxy vinyl ester resin, obtained by reacting a novolak epoxy resin with acrylic acid, with a polybasic acid anhydride, then reacting the acid group, formed by the reaction, with glycidyl methacrylate, and further reacting the secondary hydroxyl group, formed by this reaction, with a polybasic acid anhydride. The acid group-containing vinyl ester resin contains 1.75 to 3.5 radically polymerizable unsaturated double bonds per aromatic ring and contains the acid group in such an amount range that the acid value is 30 to 150 mg KOH/g. The photosensitive resin composition is a resin composition for a resist ink that simultaneously has ultrahigh sensitivity, excellent developability, and a broad heat control width. |