| abstract |
The invention relates to a stable epoxy resin dispersions and also a process for the preparation thereof and the use thereof, in particular for coatings. The epoxy resin dispersions which are remarkable, in particular, for good storage stability with a low content of organic solvents at the same time and little tendency to skin formation and yield coatings with good surface properties, contain, in addition to water, optionally small quantities of organic solvents and also optionally usual additives, as an essential constituent a condensation product of (a) 50 to 80% by weight of an epoxy compound containing at least two epoxy groups per molecule and having an epoxy equivalent to of 100 to 2,000. (b) 35 to 17% by weight of an aromatic polyol and (c) 15 to 3% by weight of a condensation product of an aliphatic polyol with a molecular weight (Mw) of 200 to 20,000, an epoxy compound containing at least two epoxy groups per molecule and having an epoxy equivalent of 100 to 2,000, and of a mono- and/or polyisocyanate, the equivalent ratio of the OH groups to the epoxy groups being 1:0.85 to 1:3.5, the quantity of mono- and/or polyisocyanate being 0.05 to 5% by weight, referred to the quantity of aliphatic polyol and epoxy compound, and the epoxy equivalent of said condensation product being between 200 and at least 50,000. |