| 摘要 |
PROBLEM TO BE SOLVED: To provide an industrially advantageous method for producing a water-soluble polymer containing polyvinylamine or polyamidine, which controls a coalescence phenomenon of each water-soluble polymer particle, even though using hydrochloric acid in a modification process. SOLUTION: The method for producing the water-soluble polymer of a slurry state includes sequentially: a polymerization process of obtaining a slurry of (co)polymer particles by suspension-polymerizing an aqueous monomer solution which contains N-vinyl carboxylic acid amide, or the amide and another copolymerizable component, and a polymerization initiator, in the presence of an emulsifier in a hydrophobic organic solvent; and a modification process of modifying the resultant slurry of (co)polymer particles by adding hydrochloric acid thereto. In the method, the monomer concentration of the aqueous monomer solution in the modification process is 20-80 wt.%, the concentration of hydrochloric acid in the modification process is 25-40 wt.%, a distillation-dehydration process is set between the polymerization process and the modification process, and the distillation-dehydration is carried out so that the water content of a polymerization system, calculated including a water content accompanied by hydrochloric acid in the modification process, becomes≤35 wt.%. COPYRIGHT: (C)2012,JPO&INPIT |
