Copolymers ABCDE obtainable by polymerising a monomer mixture comprising olefinically unsaturated monomers A having at least one urethane group —O—CO—NH—, basic (meth)acrylic monomers B which comprise at least one tertiary amino group, alkyl(meth)acrylates C, wherein the alkyl residue is linear, branched, or cyclic, and may have from 1 to 20 carbon atoms, olefinically unsaturated compounds D having at least one hydroxyl group in the molecule, preferably hydroxyalkyl(meth)acrylates, olefinically unsaturated compounds E having none of the functional groups of monomers A and C, and no acid groups, which are neutralised to an extent of from 10% to 100% and dispersed in water, and a method of use thereof as paste resins