Methods to reduce organic impurity levels in polymers and products made therefrom
AssigneeBuckman Laboratories International, Inc.
InventorsMark L. Zollinger, James Andrew Ward
Life of this patent
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Abstract
Various methods are described for preparing dry water-soluble polymers with reduced organic impurity content by combining water-soluble polymer in water with at least one dry polar solvent to form a mixture that separates into a first layer comprising a majority of the solvent and water and a second layer comprising a majority of the polymer, then separating the layers and drying the second layer to obtain a solid comprising the water-soluble polymer. Further, or solid polymer products having reduced organic impurity levels and/or moisture content are also described.
Claims23
A method of preparing dry water-soluble polymer comprising:
- a) combining a water-soluble polymer in water with at least one dry polar solvent to form a mixture that separates into a first layer comprising a majority of said dry polar solvent and water and a second layer comprising a majority of said water-soluble polymer, wherein said water-soluble polymer is an ionene polymer, a polyaminoamide polymer, or a polyacrylamide/diallyldimethyl-ammonium halide copolymer;
- b) separating said first layer from said second layer;
- and
- c) drying said second layer to obtain a solid comprising said water-soluble polymer, wherein said water-soluble polymer having at least one polar solvent content or impurity level selected from:
- a polar solvent content of from about 5 ppm to about 1,000 ppm,
- a low molecular weight organic impurity level of from about 50 ppm to about 5,000 ppm, wherein the low molecular weight organic impurity has an average molecular weight of 50,000 or less,
- an epichlorohydrin or daughter thereof impurity level of from about 50 ppm to about 5,000 ppm, and
- an impurity level of from 5 ppm to about 1,500 ppm with respect to impurities soluble in an organic solvent.
An ionene polymer powder having a polar solvent content of from about 5 ppm to about 1,000 ppm.
A wet strength resin powder comprising wet strength resin and an epichlorohydrin or daughter thereof impurity level of from about 50 ppm to about 5,000 ppm, wherein said wet strength resin powder is a polyaminoamide polymer.
A water-soluble polymer solid comprising water-soluble polymer and an impurity level of from 5 ppm to about 1,500 ppm with respect to impurities soluble in an organic solvent, wherein said water-soluble polymer is an ionene polymer, a polyaminoamide polymer, or a polyacrylamide/diallyl-dimethylammonium halide copolymer.
Dependencies are inferred from the claim text.