Aqueous dispersion of an amphoteric water-soluble polymer, a method of manufacturing the same, and a treating agent comprising the same

Abstract

A storage stable, flowable aqueous dispersion of an amphoteric water-soluble polymer with good handling as well as a method of manufacturing the same are provided. Such an aqueous dispersion can be effectively used for flocculating and/or dehydrating sludge, or for separating and treating oil-containing industrial waste water, as a drainage aid, a retention aid, or recovering substances from white water in the papermaking process. The aqueous dispersion of an amphoteric water-soluble polymer is obtained by polymerizing a mixture of monomers comprising a specific cationic monomer and an anionic monomer as essential components wish stirring in an aqueous salt solution incapable of dissolving the produced polymer and in the presence of a polymer electrolyte dispersant soluble in said aqueous salt solution. Such an aqueous dispersion is highly effective when the concentration of the produced amphoteric water soluble polymer in the aqueous dispersion, the concentration of the salt, the concentration of the dispersant, the viscosity of the aqueous dispersion, and the average diameter of the particles of the amphoteric water-soluble polymer in the aqueous dispersion are found within specific ranges.

Dependencies are inferred from the claim text.