Method of producing aqueous secondary dispersions of water-insoluble polymers

The present invention relates to a method of producing aqueous secondary dispersions of water-insoluble copolymers by free-radical solution polymerization of ethylenically unsaturated monomers M comprising: i) at least one hydrophobic, monoethylenically unsaturated monomer M1 with a solubility in water of not more than 30 g/l at 25° C. and 1 bar and ii) at least one hydrophilic, monoethylenically unsaturated, nonionic comonomer M2 with a solubility in water of at least 80 g/l at 25° C. and 1 bar, in an organic, water-miscible solvent or a mixture of water with an organic, water-miscible solvent as polymerization medium and subsequent replacement of the organic solvent by water in which, toward the end of the polymerization, some of the monomers M are added in the form of a monomer composition M' which comprises essentially only monomers M2 as monomers. The present invention also relates to the aqueous polymer dispersions obtainable by the method according to the invention and to their use, particularly in pharmacy and cosmetics.