WATER DISPERSIBLE POLYESTER POLYURETHANE RESIN

Laterally stabilized, water-miscible polyester polyurethane resins, useful as principal binder resins and as pigment grind resins in water-borne coating systems are the reaction product of one or more polyols, one or more polyisocyanates, and a polyester prepolymer formed by the reaction of a polyether alcohol, one or more polyols, and one or more polyfunctional carboxylic acids. The resins have a polyester polyurethane backbone with pendant polyether groups, attached to the polyester segments of the backbone, which serves to solubilize and stabilize the resins in aqueous media. The resins have small dispersion particle size at the same or higher molecular weights than similar prior art resins, and produce better metal flake orientation when used as the principal resins in base coat formulations which contain aluminum and mica particles for "metallic" effect coating finishes.