| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a water-soluble polymer which can decrease the amount of residual monomers, and also can more increase monomer concentration in a reaction mixture, and moreover can narrow the molecular weight distribution of the polymer obtained. SOLUTION: The rate of chain transfer agent added to monomer is changed at least once in the predetermined period in a polymerization period when the chain transfer agent is added continuously and the water-soluble polymer is produced. As the method of changing the addition rate at least once, on concrete target, examples are(i) a method to heighten the addition rate gradually;(ii) a method to heighten the addition rate continuously;(iii) a method to lower the addition rate gradually;(iv) a method to lower the addition rate continuously; and the like. COPYRIGHT: (C)2005,JPO&NCIPI
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