Aqueous coating composition based on specific two-component polyurethanes and to a process for its production

Abstract

The present invention is directed to a two-component coating composition which contains as binder components a) a polyol component containing at least one hydroxyl-containing polymer having chemically incorporated carboxylate and/or sulfonate groups and based on olefinically unsaturated compounds and b) a polyisocyanate component having a viscosity at 23.degree. C. of about 50 to 10,000 mPa.s and based on at least one organic polyisocyanate in quantities corresponding to an NCO/OH equivalent ratio of about 0.5:1 to 5:1, characterized in that component a) is an aqueous solution and/or dispersion of a polymer containing hydroxyl groups in which the polyisocyanate component b) is present in emulsified form. The present invention also relates to a process for the production of this coating composition which is characterized in that a polyisocyanate component having a viscosity at 23.degree. C. of about 50 to 10,000 mPa.s and based on at least one organic polyisocyanate is emulsified in an aqueous solution or dispersion of one or more polymer resins containing hydroxyl groups and chemically incorporated sulfonate and/or carboxylate groups in a quantity which makes them soluble and/or dispersible in water, the quantitative ratios between the two components corresponding to an NCO/OH equivalent ratio, based on the isocyanate groups of the polyisocyanate component and the incorporated hydroxyl groups of the polymer component, of about 0.5:1 to 5:1.

Dependencies are inferred from the claim text.