Process for preparing a water-in-oil emulsion

摘要

A process for preparing a water-in-oil emulsion of a water-soluble polymer is disclosed, comprising polymerizing at least one water-soluble vinyl monomer in a water-in-oil emulsion, wherein the dissolved oxygen concentration of the emulsion under polymerization is about 100 ppb or less. The desired emulsion can be obtained without being accompanied by the formation of agglomerates.