ELECTRODEPOSITION PAINT COMPOSITION WHICH FORMS THICK TWO-LAYER COATING FILM

PURPOSE:To provide the titled compsn. which can afford thick coating film in a short time and can form a two-layer coating film composed of a lower epoxy layer having good corrosion resistance and an upper acrylic layer having good weather resistance, containing a specified acrylic resin and a specified epoxy resin in a specified ratio. CONSTITUTION:The titled compsn. contains a cationic acrylic resin (A) having a softening point of 80 deg.C or above and a cationic phenolic epoxy resin (B) having a softening point of 75 deg.C or below in a weight ratio of A/B of 1-30/1. When the benzene nucleus- contg. monomer content of the resin A accounts for more than 50wt% of the entire acrylic composition, the resin A is well compabible with the resin B so that a clear two-layer film cannot to formed. When the softening point of the resin A is lower than 80 deg.C, a thick coating film cannot be obtd. while when the softening point of the resin B is higher than 75 deg.C, a difference in viscosity between the resins A and B is too small and a two-layer film cannot be formed. When the ratio of A/B is less than 1, the upper and lower layers are poorly separated from each other and hence, a film having good resistance to corrosion and weather can not be obtd., while when the ratio exceeds 30, a substrate can not be uniformly, continuously coated with the lower layer.