abstract |
The present invention relates to two-component, aqueous polyurethane coating compositions which may be cured at ambient temperature and which contain I) a polyisocyanate mixture having an NCO content of 10 to 47% by weight and containing isocyanurate and allophanate groups in a molar ratio of monoisocyanurates to monoallophanates of 10:1 to 1:5, wherein the allophanate groups are formed from urethane groups which are based on the reaction product of an organic diisocyanate having (cyclo)aliphatically bound isocyanate groups and a monoalcohol containing at least 1 carbon atom and having a molecular weight of up to 500, and II) a water dispersible or water soluble polyol, wherein components I and II are present in an amount sufficient to provide an equivalent ratio of isocyanate groups to hydroxyl groups of 0.8:1 to 6:1. The present invention is also directed to the coatings prepared from these coating compositions. |