Patent ID: 6420478
Filing Date: 2002-07-16
Classification: C08G,C09D

Abstract:
An aqueous binder composition comprisingA) 70 to 99% of a polyurethane dispersion having an OH number of <10 mg KOH/g of solid resin and B) 1 to 30% of a water-dispersible polyisocyanate mixture prepared from an aliphatic, cycloaliphatic, araliphatic and/or aromatic diisocyanate, wherein the polyisocyanate mixture has a) an average isocyanate functionality of at least 2.0, b) a content of isocyanate groups (calculated as NCO; molecular weight 42) of 5.0 to 25.0 wt. %, and c) a content of ethylene oxide units of 2 to 50 wt. % (calculated as C2H4O; molecular weight 44) present 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 and wherein the solids contents of components A) and B) add up to 100 wt. %.