| abstract |
(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide a novel water-soluble polymer compound having excellent dispersion performance, resistance to divalent metal ions, and excellent dehydration reduction performance of mud water. A modified polyvinyl alcohol useful as a regulator is obtained. SOLUTION: The structural unit comprises the following structural units (I) and (II), and the content of (I) is 3.0 to 45.0 mol%, The content of (II) is 97.0 to 55.0 mol%, A modified polyvinyl alcohol having a weight average molecular weight of 3,000 to 400,000. Embedded image (In the formula, R represents H or CH 3 , and M represents H, alkali metal, ammonium, alkylammonium, or alkanolammonium.) |