Aqueous two-component polyurethane coating compositions

Abstract

The present invention relates to a coating composition containing A) 30 to 99 wt. % of an aqueous hydroxy- and/or amino-functional resin dispersion and B) 1 to 70 wt. % of a water dispersible polyisocyanate mixture prepared from aliphatic, cycloaliphatic, araliphatic and/or aromatic diisocyanates and having a) an average isocyanate functionality of at least 2.0, b) a content of 5.0 to 25.0 wt. %, based on resin solids, of isocyanate groups (calculated as NCO; molecular weight=42) and c) a content of 2 to 50 wt. %, based on resin solids, of ethylene oxide units calculated as C2H4O; molecular weight 44) incorporated within polyether chains containing an average of 5 to 35 ethylene oxide units, wherein at least 60 mole % of the polyether chains are connected via allophanate groups to two polyisocyanate molecules which are each prepared from at least two diisocyanate molecules. The present invention also relates to the use of these coating compositions for preparing coatings, primers and sealing compositions, in particular for automotive refinish and original equipment manufacture.

Dependencies are inferred from the claim text.