Patent ID: 8476391

Claim:
A process for the production of anionic water-in-water polymeric dispersions comprising at least one finely dispersed, water-soluble and/or water-swellable polymer A, comprising anionic monomer units and, optionally, one or more of non-ionic, amphiphilic, and cationic monomer units, having a M w of >1.0×10 6 g/mol and a continuous aqueous phase, which phase contains a first portion of a polymeric dispersing agent B and said polymeric dispersing agent B consists of potassium polyacrylate having an average molecular weight Mw of 65,000-75,000 g/mol, wherein the aliquot is present in an amount of at least 5% by weight, based on the weight of the total dispersion, the process comprising: free radically polymerizing a monomer composition comprising at least the anionic monomers and, optionally, the non-ionic, amphiphilic, and cationic monomer units in the presence of at least 5% by weight of said potassium polyacrylate dispersing agent B based on the total weight of the dispersion and from 0.9% by weight to 1.5% by weight of an inorganic salt based on the total weight of the dispersion, to form a reaction mixture, and on completion of said polymerization, diluting the reaction mixture with a second portion of said potassium polyacrylate dispersing agent B, wherein the anionic monomers are selected from the group consisting of a.) an olefinically unsaturated carboxylic acid, a carboxylic anhydride, a water-soluble alkali metal salt thereof, an alkaline earth metal salt thereof, and an ammonium salt thereof.