| abstract |
Disclosed are a resin dispersion and a low-temperature curable cationic electrodeposition coating composition including the same, in which the dried coating film of the electrodeposition paint is lead-free and has an epoxy-acrylic double-layered structure for displaying excellent properties, and in which an organic solvent content can be minimized. The resin dispersion includes a cationic electrodeposition resin, deionized water, an acid for a neutralization, a reaction product of manganese phosphate and an acid diluted to a concentration of 10% in deionized water and a cationic surfactant. The cationic electrodeposition resin can be prepared in the presence of an organic solvent from (a) a cationic electrodeposition synthetic resin produced by an epoxy-amino addition reaction (b) an acrylic cationic electrodeposition resin having an amino group (c) a fatty acid ester resin synthesized by an esterification reaction of styrene-allylalcohol copolymer and fatty acid and (d) polyurethane cross-linking agent produced from a mixture of blocked polymethylene polyphenyl polyisocyanate and blocked isophorone diisocyanate. The cationic electrodeposition coating composition has a superior low-temperature curability. The cured film has an epoxy-acrylic double-layered structure to give a high functionality, for improving properties such as weather-resistance, yellowing resistance, etc. |