| abstract |
PURPOSE: To obtain a water-base coating composition suitable for undercoating of metal or plastic by blending a principal resin comprising an anionic polyurethane with a crosslinking aminoplast resin, a branched polyester resin and a ground anionic acrylic resin. n CONSTITUTION: This composition contains a principal resin (A) comprising an anionic polyurethane, a crosslinking aminoplast resin (B), a branched polyester resin (C), and a ground anionic acrylic resin (D) respectively in amounts of about 5-60 wt.%, about 5-50 wt.%, about 5-35 wt.% and about 2-75 wt.% based on the final solid content of the undercoating composition. The component A is a reaction product of a polyester component obtained by reacting a mixture of a long-chain carboxylic acid and a short-chain carboxylic acid with an alcohol containing at least two OH groups, with a polyfunctional compound, a compound containing active hydrogen groups, and a polyisocyanate. The component D is a reaction product of an alkyl acrylate, a hydroxyalkyl acrylate and an α,β-ethylenically unsaturated carboxylic acid. n COPYRIGHT: (C)1991,JPO |