Abstract: A carboxyl resin according to the present invention is obtained by a process including following steps: epoxy groups on a resin (a) having two or more epoxy groups in one molecule is made to react with 0.3-0.85 mol of a monocarboxylic acid (b) per one epoxy-group equivalent weight to obtain a reaction product (c); the epoxy group or groups on the reaction product (c) are made to react with 0.15-0.95 mol of a polybasic acid (d) per one epoxy-group equivalent weight to obtain a reaction product (e); and the epoxy group or groups on the reaction product (e) are further made to react with 1.0-5.0 mol of a monocarboxylic acid (f) per one epoxy-group equivalent weight. The carboxyl resin thus obtained has an acid value within a range from 20 to 200 mgKOH/g and is soluble in an organic solvent.

Abstract: A carboxyl resin according to the present invention is obtained by a process including following steps: epoxy groups on a resin (a) having two or more epoxy groups in one molecule is made to react with 0.3-0.85 mol of a monocarboxylic acid (b) per one epoxy-group equivalent weight to obtain a reaction product (c); the epoxy group or groups on the reaction product (c) are made to react with 0.15-0.95 mol of a polybasic acid (d) per one epoxy-group equivalent weight to obtain a reaction product (e); and the epoxy group or groups on the reaction product (e) are further made to react with 1.0-5.0 mol of a monocarboxylic acid (f) per one epoxy-group equivalent weight. The carboxyl resin thus obtained has an acid value within a range from 20 to 200 mgKOH/g and is soluble in an organic solvent.

Abstract: An ultraviolet curable resin composition comprises (A) an ultraviolet curable resin obtained by reacting an epoxy group containing polymer (a), which is prepared by polymerizing an ethylenically unsaturated monomer component including an ethylenically unsaturated monomer (i) having an epoxy group, with an ethylenically unsaturated monomer (b) having a carboxyl group, and then reacting a resultant intermediate product with a saturated or unsaturated polybasic acid anhydride (c); (B) an epoxy compound having at least two epoxy groups in molecule; (C) a photopolymerization initiator; and (D) a diluent The ultraviolet curable resin includes 0.3 to 10 mol of a polymerizable unsaturated group in 1 kg thereof. A photo solder resist ink containing this resin composition has the capability of providing a permanent film with excellent flexibility and solder heat resistance, and is preferably used to manufacture flexible printed circuit boards.

Abstract: An ultraviolet curable resin composition comprises (A) an ultraviolet curable resin obtained by reacting an epoxy group containing polymer (a), which is prepared by polymerizing an ethylenically unsaturated monomer component including an ethylenically unsaturated monomer (i) having an epoxy group, with an ethylenically unsaturated monomer (b) having a carboxyl group, and then reacting a resultant intermediate product with a saturated or unsaturated polybasic acid anhydride (c); (B) an epoxy compound having at least two epoxy groups in molecule; (C) a photopolymerization initiator; and (D) a diluent The ultraviolet curable resin includes 0.3 to 10 mol of a polymerizable unsaturated group in 1 kg thereof. A photo solder resist ink containing this resin composition has the capability of providing a permanent film with excellent flexibility and solder heat resistance, and is preferably used to manufacture flexible printed circuit boards.