| 摘要 |
PROBLEM TO BE SOLVED: To provide a (meth)acrylic acid copolymer which demonstrates the more excellent gel resistance as well as having a good chelating power and a dispersive power, and to provide a production method of the same. SOLUTION: The copolymer is a copolymer which contains a constitutional unit (a) derived from a specific structure of a (meth)acrylic acid monomer (A), and a constitutional unit (b) derived from a monoethylenically unsaturated monomer (B), which is copolymerizable with the (meth)acrylic acid monomer, and the (meth)acrylic acid copolymer has a sulfonic acid group at the end of the principal chain at least at one side (wherein, the sulfonic acid group may be a salt of ammonium, alkali metal or an organic amine), the constitutional unit (b) contains at least a constitutional unit (b1) derived from a specific structure of (meth)allyl ether monomer (B1), and the interrelated ratio of the constitutional unit (a) and the constitutional unit (b1) is the constitutional unit (a) of 70-95 mole % and the constitutional unit (b1) of 5-30 mole %. |
