LOW TEMPERATURE CURING CATIONIC ELECTRODEPOSITION RESIN COMPOSITION COMPRISING POLYHYDROXYLAMINE MODIFIED EPOXY RESIN HAVING CATIONIC GROUP OBTAINED FROM POLYEPOXIDE AND URETHANE INTERMEDIATE PREPARED BY REACTION OF GAMMA-HYDROXYLAMINE AND CARBONATE AS MAIN RESIN, AND ISOCYANATE CURING AGENT RESIN

摘要

PURPOSE: Provided is a cationic electrodeposition paint resin composition which can be cured at a low temperature of 120-150 deg.C and is very excellent in water dispersion, coating flatness and adhesion uniformity. CONSTITUTION: The cationic electrodeposition paint resin composition comprises a base resin which is prepared by reacting a polyhydroxylamine modified epoxy resin of the formula I (which is obtained by reacting a urethane intermediate prepared by the reaction of a γ -hydroxylamine having at least two hydroxyl groups and a carbonate with a polyepoxide compound) with a glycidyl ester and a primary amine to introduce a cationic group; and an isocyanate curing agent resin which is prepared by reacting an isocyanate, a blocking agent and a polyol and is deblocked at a temperature of 170 deg.C or less, wherein the ratio of the hydroxyl group of the main resin and the isocyanate group of the curing agent resin is 1:1.1 to 1:1.5 by equivalence. In the formula I, A is represented by the formula V; B is represented by the formula VI; R1 is a C2-C10 alkyl or hydroxyalkyl group; and R2 is H or a C2-C10 alkyl or hydroxyalkyl group.