PURPOSE: To produce the titled polymer by easy concentration by ultrafiltration, by controlling the pH value of a reaction mixture containing an acrylamide polymer subjected to Hofmann degradation to a specified value and effecting the ultrafiltration of the reaction mixture.
CONSTITUTION: A reaction mixture containing an acrylamide polymer in which usually at least 20mol% of the amide groups are subjected to Hofmann degradation is obtained by reacting an acrylamide polymer in an aqueous solution with a hypohalite (e.g., sodium hypochlorite) in the presence of an alkali. Next, the pH value of this solution is controlled to 6W11, and the solution is concentrated by an ultrafilter. This pH control makes it possible to carry out the ultrafiltration easily and to effect the concentration of good polymer consistently.
IMANARA TOORU
TATE MASAO
NAKANISHI YASUYUKI
TSURUGA MASAHIRO
SATOU SHINICHI
