Abstract: The invention relates to 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in organic impurities from the solution of the epihalohydrin polymer, and separating extracted impurities from the withdrawn fluid, wherein the fluid comprises a substance that at atmospheric pressure and room temperature (about 25° C.) is gaseous.

Abstract: The invention relates to 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in organic impurities from the solution of the epihalohydrin polymer, and separating extracted impurities from the withdrawn fluid, wherein the fluid comprises a substance that at atmospheric pressure and room temperature (about 25° C.) is gaseous.

Abstract: The invention comprises an aqueous solution comprising a water-soluble, polyamidoamine- epichlorohydrin resin, said solution having a reduced halogen content and effective wet strength agent properties, obtained by subjecting an aqueous solution comprising a water-soluble polyamido-amine-epichlorohydrin resin to an organic halogen content reducing after-treatment wherein the total halogen content is below 1% by weight, calculated on solid resin and the halogen content is below 0.1% by weight.

Abstract: The disclosed invention pertains to a process for the preparation of a water-soluble, nitrogen-containing, epihalohydrin-based resin having a reduced content of total halogen, organic halogen, adsorbable organic halogen (AOX)and by-products. The process involves treatment of nitrogen-containing, epihalohydrin-based resins or intermediate reaction-products with a basic ion-exchanger. The invention also pertains to novel resins displaying such halogen contents far below the values known in the art. Subject resins are useful as wet-strength agents for paper and are preferably of the polyaminoamide-epihalohydrin type.