COMPOSITE PAINT FILM COATING

摘要

The composite paint film coating comprises an electrodeposition paint film (I) coated on a sheet-steel automotive outer panel, and an intermediate paint film (II) coated on the first paint film. The electrodeposition paint film has a minimum melt viscosity ( lambda min) not less than 0.2 during hardening. The electrodeposition paint film is formed of cathodic electrodeposition paint composition which includes a cationic thermosetting resin (1), and an already cross-linked particulate resin (2). The particulate resin (2) is an addition-polymer formed between a first compound (A) having at least two primary amino groups in a molecule, and a second compound (B) having at least two alpha , beta -ethylenic unsaturated groups. The particulate resin (2) has an average particle size of 0.01 to 1 mu m. The weight ratio ((2)/(1)) in solid content between the cationic thermosetting resin (1) and the particulate resin (2) is within a range from 0.03 to 0.15. The intermediate paint film (II) has a hardening starting time of 5 to 20 minutes.