| 摘要 |
PURPOSE:To obtain the titled copolymer useful as a dispersant, etc. having narrow molecular weight distribution, etc. in high polymerization ratio, by neutralizing partially maleic acid and (meth)acrylic acid with an alkali metal hydroxide, etc., polymerizing them in an aqueous solution, polymerizing them further while adding an alkali to the polymerization mixture. CONSTITUTION:In preparing a copolymer of (A) maleic acid (MA for short) and (B) (meth)acrylic acid (AA for short) in an aqueous medium, an aqueous solution of MA or MA and AA is neutralized with (C) an alkali metal hydroxide or ammonia in a molar ratio of MA/C of 100/0-90, and if necessary, polymerization is carried out in the presence of a polymerization initiator while adding dropwise AA to the polymerization system. As the component C is added to the polymerization system, polymerization is carried out by adding dropwise AA and the polymerization initiator, to give the desired copolymer having a molar ratio of MA+AA/C of 100/MA(Mmol)-100/[1.3MA(mol)+0.3AA(mol) when MA+AA is 100(mol).
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