Method of forming dry coating film and paint used for the same

A method for forming a dry coating film with a colored paint on a surface of an object to be coated, comprising the steps of:

• [1] setting a dry coating film thickness T such that a coating film having the dry coating film thickness T and formed of the colored paint hides the surface of the object to be coated, and T is selected from a range not smaller than 320 μm;
• [2] formulating or preparing the colored paint such that it will satisfy a color difference ΔE1 defined in (c) below, the colored paint containing at least a binder resin, a scaly pigment and a color pigment, the scaly pigment satisfying conditions (a) and (b) below:
• (a) the scaly pigment having an average particle size from 10 to 300 μm, an average thickness from 2 to 50 μm and an aspect ratio from 2 to 20, the aspect ratio being defined as the average particle size/the average thickness,
• (b) a content of the scaly pigment is from 5 to 45 volume % in components forming the coating film, and
• (c) the color difference ΔE1 between the coating film having the dry coating film thickness T and formed of the colored paint and a coating film having a dry coating film thickness of 0.7 T and formed of the colored paint is not smaller than 2.0, wherein the color difference ΔE1 is a color difference in accordance with JIS K 5600-4-5:1999;
• [3] coating the surface of the object to be coated with the colored paint until the surface is hidden by the coating film formed of the colored paint;
• and
• [4] obtaining a dry coating film by drying the coating film obtained in the step [3];
• wherein the binder resin comprises an epoxy resin or a modified product thereof selected from the group consisting of a carboxylic acid modified epoxy resin, an amine modified epoxy resin, a phosphoric acid modified epoxy resin, a petroleum resin modified epoxy resin, a rubber modified epoxy resin and mixtures thereof.