Patent ID: 6426383
Filing Date: 2002-07-30
Classification: C02F,C08F

Abstract:
A method for preparing an aqueous dispersion of discrete particles of a water soluble polymer comprising polymerizing in an aqueous solution of anionic salt in the presence of a water-soluble stabilizer polymer under free radical forming conditions at a pH of from about 5 to about 8:a) 5-50 weight percent of a mixture containing i. 1-99 mole percent of a vinylamide monomer of formula H2C=CR2NRC(O)R1 â€ƒwherein R, R1 and R2 are independently selected from hydrogen, C1-C20 alkyl groups, aryl groups and alkylaryl groups; and, ii. 99-1 mole percent of at least one water soluble vinyl monomer selected from vinyl acetate, diallyldimethyl ammonium chloride, vinyl pyrrolidinone, acrylonitrile, dimethylaminoethylacrylate methyl chloride quaternary salt, dimethylaminoethylacrylate benzyl chloride quaternary salt, dimethylaminoethylacrylate methyl sulfate quaternary salt, dimethylaminoethylacrylate cetyl chloride quaternary salt, dimethylaminoethylmethacrylate cetyl chloride quaternary salt, dimethylaminoethylmethacrylate methyl chloride quaternary salt, dimethylaminoethylmethacrylate benzyl chloride quaternary salt, dimethylaminoethylmethacrylate methyl sulfate quaternary salt, â€ƒwherein the stabilizer polymer has an intrinsic viscosity in 1M NaNO3 of from about 0.1-10 dl/g and comprises from about 0.1 to about 5 weight percent based on the total weight of the dispersion, the water soluble salt is selected from ammonium, alkali metal and alkaline earth metal halides, sulfates, phosphates, nitrates and combinations thereof and comprises from about 5 to about 40 weight percent based on the total weight of the dispersion and the dispersion has a viscosity of less than about 25,000 cps at 25Â° C., wherein the stabilizer polymer is selected from the group consisting of poly(vinyl alcohol), partially hydrolyzed poly(vinyl acetate), hydrolyzed poly(vinyl acetate/N-vinyl formamide), poly(vinyl alcohol/acrylamide), poly(diallyldimethyl ammonium chloride), poly(dimethylaminoethyl acrylate methyl chloride quaternary salt), poly(dimethylaminoethyl methacrylate methyl chloride quaternary salt), poly(dimethylaminoethyl acrylate benzyl chloride quaternary salt), poly(dimethylaminoethyl methacrylate benzyl chloride quaternary salt), poly(diallyldimethyl ammonium chloride/dimethyaminoethyl acrylate methyl chloride quaternary salt), poly(diallyldimethylammonium chloride/dimethylaminoethyl methacrylate methyl chloride quaternary salt), poly(diallyldimethylammonium chloride/dimethylaminoethyl acrylate benzyl chloride quaternary salt), and poly(diallyldimethyl ammonium chloride/dimethylaminoethyl methacrylate benzyl chloride quaternary salt) and combinations thereof.