Preparation of aqueous epoxy resin dispersions, and their use

Claim 1

A process for the preparation of an aqueous epoxy resin dispersion containing from 40 to 75% by weight of water, wherein (A) an epoxy resin having more than one 1,2-epoxide group per molecule is reacted with (B) from 1 to 30% by weight, based on the epoxy resin (A), of a protective colloid which contains basic nitrogen and has an amine number of from 10 to 90, said protective colloid being a copolymer which contains, as copolymerized units, vinyl propionate and vinylpyrrolidone as well as vinylimidazole, vinylpyridine or dimethylaminoethyl acrylate or methacrylate, with or without up to 35% by weight of other copolymerizable ethylenically unsaturated compounds in the presence of (C) from 50 to 1,000 mole percent, relative to the amount of basic nitrogen in the protective colloid (B), of an acid, and in the presence or absence of one or more organic solvents, at from 50° to 150° C., the reaction product is dispersed by adding water and any organic solvent present is then distilled off.