Process for the preparation of dispersion of water-soluble cationic polymer

摘要

The present invention relates to the preparation of a dispersion wherein a copolymer comprising an acrylic monomer containing a dialkylbenzylammonium group is dispersed in an aqueous solution of a salt as fine particle. Two cationic polymers are used in the polymerization of the above monomer in the aqueous solution of a salt. One of the cationic polymers is a (co)polymer comprising an acrylic monomer containing a trialkylammonium group which is soluble both in the aqueous solution of a salt and in water, while the other thereof is a copolymer comprising an acrylic monomer containing a dialkylbenzylammonium group which is soluble in water, but insoluble in the aqueous solution of a salt. The above aqueous solution of a salt is an aqueous solution of a polyvalent anion salt such as sulfate or phosphate. A dispersion of a water-soluble cationic polymer can be prepared by dissolving the above monomer in the aqueous solution and carrying out the polymerization in the presence of the above two polymers.