| 摘要 |
PROBLEM TO BE SOLVED: To provide an intermediate coat-less (two-coat coating system) coating method by a double-layer coating film with the appearance, weatherability and corrosion resistance equivalent to those of a three-coat one sufficiently maintained. SOLUTION: An aqueous paint composition containing two kinds of resin components incompatible each other, a curing agent and a pigment is electrodeposited on a conductive substrate, then layer-separated while being heated and subsequently cured to form a double-layer cured film consisting at least of two layers. In this process, the distribution of the pigment is controlled so that the pigment concentration (a) in the resin layer in direct contact with air is increased in relation to the pigment concentration (b) in the resin layer in direct contact with the substrate. For example, the solubility parameterδa of the resin component constituting the resin layer in direct contact with air and the solubility parameterδb of the resin component constituting the resin layer in direct contact with the substrate are limited to conform to (δb-δa) >=1.0.
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