METHOD FOR FORMING COATING FILM USING CATIONIC ELECTRODEPOSITION COATING COMPOSITION ALSO SERVING AS INTERMEDIATE COATING

摘要

PROBLEM TO BE SOLVED: To provide a method for forming a coating film, with which a cationic electrodeposition coating composition also serving as an intermediate coating having excellent corrosion resistance, solvent resistance, weather resistance and adhesivity to the coating film of a top coating and yet actualizing the same appearance of coating film as that of three-coat coating even by two-coat coating is used. SOLUTION: Electrodeposition coating is carried out by using the cationic electrodeposition coating composition also serving as an intermediate coating in which an acrylic resin (a1), a polyester resin (a2) and a blocked polyisocyanate (c1) dispersed in an aqueous medium form an emulsion particle of a core-shell structure composed of a shell part containing the acrylic resin (a1) and the blocked polyisocyanate (c1) and a core part containing the polyester resin (a2) and the blocked polyisocyanate (c1) and an epoxy resin (b) and a blocked polyisocyanate (c2) form an emulsion particle separately from the emulsion particle of the core-shell structure. COPYRIGHT: (C)2003,JPO