Stable aqueous epoxy resin dispersion, process for its preparation and its use

The invention relates to stable epoxy resin dispersion and a process for their preparation and their use, in particular for coatings. The epoxy resin dispersions, which are characterized above all by good storage stability with simultaneously lower content of organic solvents and less tendency to skin formation and coatings with good surface properties, in addition to water, optionally small amounts of organic solvents and optionally conventional additives, as an essential component Condensation producta) 50 to 80% by weight of an epoxide compound having at least two epoxide groups per molecule and an epoxide equivalent weight of 100 to 2000,b) 35 to 17 wt .-% of an aromatic polyol andc) 15 to 3 wt .-% of a condensation product of an aliphatic polyol having a molecular weight (Mw) of 200 to 20,000, an epoxy compound having at least two epoxide groups per molecule and an epoxide equivalent weight of 100 to 2000 and of a mono- and / or Polyisocyanate, wherein the equivalent ratio of the OH groups to the epoxy groups 1: 0.85 to 1: 3.5, the amount of mono- and / or polyisocyanate 0.05 to 5 wt .-%, based on the amount of aliphatic Polyol and epoxy compound is, and the epoxide equivalent weight of this condensation product is between 200 and at least 50,000.