Patent ID: 7157603
Filing Date: 2007-01-02
Classification: C08F

Abstract:
1. A method of separating thermally precipitabie oligomeric N-substituted (meth)acrylamides and conjugates thereof from aqueous solutions in the absence of organic solvents, said oligomeric N-substituted (meth)acrylamides having an average molecular weight between 500 g/mol and 5000 g/mol; wherein said method comprises the steps of: wherein, prior to the thermally precipitating of step a), the aqueous solution contains no organic solvents and contains from 0.1 percent by weight to 10 percent by weight of a total amount of said oligomeric N-substituted (meth)acrylamides with said molecular weight between 500 g/mol and 5000 g/mol and said conjugates thereof and from 0.01 M to 3 M of said at least one salt; and wherein said at least one salt is selected from the group consisting of potassium chloride, sodium chloride, ammonium chloride, calcium chloride, magnesium chloride, potassium acetate, sodium acetate, ammonium acetate, calcium acetate, magnesium acetate, potassium sulfate, sodium sulfate, ammonium sulfate, calcium sulfate, magnesium sulfate, and mixtures thereof.