Coating composition and method for forming coating film using same

摘要

A cationic electrodeposition coating is provided having excellent covering power (clearance application properties), edge anticorrosion properties, and finish properties. The cationic electrodeposition coating composition comprises a specific amino-group-containing epoxy resin; blocked polyisocyanate obtained by reacting an active hydrogen-containing component containing propylene glycol, and a polyisocyanate compound; and 0.1-20 mass parts of a cationic electrodepositing gelled microparticulate polymer obtained by crosslinking an acrylic copolymer containing hydrolyzable alkoxysilane groups and cationic groups, per a total of 100 mass parts of the solids fraction of the amino-group-containing epoxy resin and the blocked polyisocyanate compound.

主权项

1. A cationic electrodeposition paint composition comprising:
an amino group-containing epoxy resin; a blocked polyisocyanate obtained by reacting a polyisocyanate compound and an active hydrogen-containing component containing propylene glycol; and a cationic electrodepositing gelled microparticulate polymer, wherein:
the amino group-containing epoxy resin is a polyol-modified amino group-containing epoxy resin obtained by reacting a polycaprolactone polyol compound and an amino group-containing compound with a modified epoxy resin,the modified epoxy resin is obtained by adding caprolactone to a hydroxyl group-containing epoxy resin,the cationic electrodepositing gelled microparticulate polymer is obtained by crosslinking an acrylic copolymer containing a hydrolyzable alkoxysilane group and a cationic group; anda blending ratio of the cationic electrodepositing gelled microparticulate polymer in the cationic electrodeposition paint composition is, in terms of a solid content ratio, from 0.1 to 20 parts by mass relative to total 100 parts by mass of the amino group-containing epoxy resin and the blocked polyisocyanate compound.