METHOD OF FORMING COATING FILM

PROBLEM TO BE SOLVED: To provide a method of forming a solid color coating film by which an intermediate coating film is eliminated, a coating process is simplified, energy is saved and excellent corrosion resistance such as edge corrosion proofing property and coating film appearance are attained. SOLUTION: In the method of applying a coating film on a primer coating film formed on a metallic plate by 2 coat 1 bake system, a 1st top coating material is a coating material using an alkyd resin or a polyester resin and a melamine resin as resin components and is prepared by blending a color pigment, a rust proofing pigment containing no heavy metal and a thixotropic agent and a 2nd top coating material using an alkyd resin or a polyester resin and a melamine resin as resin components, is prepared by blending a color pigment. The film thickness of the cured coating film of the 1st top coating material is 5-30 μm, the film thickness of the cured coating film of the 2nd top coating material is 10-40 μm and the color difference ΔE* in L*a*b* color system between the coating color in the hiding thickness of the 1st top coating film and the coating color in the hiding thickness of the 2nd top coating film is ≤4. COPYRIGHT: (C)2003,JPO