Use of 2-hydroxy-2-sulfinatoacetic or their salts as initiator w / o emulsions.

Process for the preparation of water-soluble or water-swellable homopolymers or copolymers by homopolymerization or copolymerization of water-soluble monomers and / or dispersible water-radically polymerizable, if necessary, with comonomers and, if necessary, at least one crosslinker, in an inverse emulsion polymerization in the presence of at least one redox initiator pair oxidant and reductant comprising, wherein the reducing agent is 2-hydroxy-2-sulfinatoacetic acid and / or its salt.