AQUEOUS COATING COMPOSITION AND COATING METHOD USING SAME

摘要

Disclosed are (1) an aqueous coating composition which is characterized in that the composition comprises: (A) an acrylic resin-type emulsion, (B) a urethane resin-type emulsion and (C) a crosslinking agent the component (B) being a self-emulsifiable urethane emulsion prepared by subjecting a urethane prepolymer to reaction for chain extension by water and to emulsification after or during neutralization of the urethane prepolymer with a tertiary amine, the urethane prepolymer consisting essentially of (i) an aliphatic and/or alicyclic diisocyanate, (ii) a polyether diol and/or polyester diol both having a number-average molecular weight of about 500 to about 5000, (iii) a lowmolecualr weight polyhydroxyl compound and (iv) a dimethylolalkanoic acid in an NCO/OH ratio by equivalent of 1.1-1.9/1; and (2) a two-coat one-bake coating method characterized by use of said aqueous coating composition as the base-coat composition.