Patent ID: 7576162

Claim:
A process for the production of a nitrogen containing epihalohydrin polymer involving reaction of a nitrogen-containing precursor selected from the group consisting of amines, poly-amines, polyaminoamides, polyurethanes and mixtures thereof with epihalohydrin to form of a solution of said epihalohydrin polymer, the process comprising a purification step to remove organic impurities from the formed solution of the epihalohydrin polymer, said purification step comprising contacting the solution of the epihalohydrin polymer with a fluid under liquid, supercritical or near supercritical conditions to effect extraction of organic impurities from the solution of the epihalohydrin polymer to the fluid, withdrawing fluid enriched in organic impurities from the solution of the epihalohydrin polymer, and separating extracted impurities from the withdrawn fluid, wherein the fluid comprises a substance that at atmospheric pressure and room temperature (about 25° C.) is gaseous.