| 摘要 |
PROBLEM TO BE SOLVED: To obtain a highly corrosion-resistant and highly weather-proof cationic electrodeposition coating composition, especially for two-coat finish. SOLUTION: This composition is obtained by dispersing (a) an amine-modified polyphenol polyglycidyl ether-type epoxy resin, (b) an alicyclic blocked polyisocyanate curing agent, and if necessary, (c) an amino group-containing acrylic copolymer in an aqueous medium containing a neutralizer at such a ratio of the component (a) to component (b) that the cured coating film exhibits an extensibility of 3% or lower, a dynamic glass-transition temperature of 110 deg.C or higher, and a crosslink density of 1.2×10<-3> mol/cm<3> .
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