Waterborne primer for corrosion protection of air dry, waterborne metallic coatings

摘要

An aqueous coating composition, comprisingPPA) an aqueous anionic polyacrylate or polyurethane dispersion obtainable by dispersingPP1) a polyacrylate resin, having functional groups selected from the group consisting of carboxylic acid groups, carboxylic anhydride groups or mixtures thereof in water in the presence of ammonia, or,PP2) a fully reacted polyurethane resin, formed from the reaction of a glycol or polyol of polyester or polyether with a diisocyanate, and then neutralized with ammonia or other amine, and dispersed in waterPPB) a phosphorous containing pigmentPPC) additives selected from the group consisting of pigments, solvents, rust inhibitors, dispersants, surfactants or mixtures thereof.PPThe coating composition is useful as a primer for metal substrates in combination with a waterborne basecoat to give a stable metallic effect.