| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an acrylic acid salt polymer such as sodium polyacylate in a continuous process while keeping a weight-average molecular weight of about 2,000-30,000, low contents of a Michael addition product, narrow molecular weight distribution and high conversion. SOLUTION: A polyacrylic acid salt is continuously produced in by polymerizing an acrylic monomer using a continuous reaction apparatus composed of plural reactors, wherein at least the 1st reactor is a tank reactor. The polymerization is carried out in aqueous solution maintaining pH at <=3.5 while continuously charging the acrylic monomer, a polymerization initiator and a bisulfite to the 1st reactor. The reactor solution discharged from the 1st reactor is continuously introduced into the 2nd reactor together with the polymerization initiator to continue the polymerization. In the 2nd reactor or the following reactors, the reaction solution is neutralized with an alkali to adjust the pH of 6-9.
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