| 摘要 |
PROBLEM TO BE SOLVED: To readily produce the subject dispersion, having a uniform deposited state of particles and a controlled hydrolytic ratio and useful as a flocculant, etc., for waste water from a polymer having N-vinylcarboxamide units by dissolving an inorganic salt in an aqueous medium so as to be present therein. SOLUTION: (C) An inorganic salt (e.g. a nitrate) is dissolved in an aqueous medium so as to be present therein in hydrolyzing (A) a polymer having N- vinylcarboxamide units (e.g. poly-N-vinylformamide) with (B) an acid or an alkali. Furthermore, e.g. the dispersion has >=1dl/g intrinsic viscosity measured by using a 1N aqueous solution of sodium chloride as a solvent at 30 deg.C and the component (A) is preferably a copolymer of N-vinylformamide and acrylonitrile. The molar amount of the component (B) used is preferably 1-5 times based on the component (A) and the concentration of the component (A) is preferably 10-40wt.%. The concentration of the component (C) is preferably 0.1-40wt.% and the hydrolytic reactional temperature is preferably 40-100 deg.C. |
