PROBLEM TO BE SOLVED: To provide a poly(meth)acrylic acid partially neutralized product characterized by giving very little insoluble ingredients in its aqueous solution and very low viscosity of its aqueous solution and having small change with the lapse of time, and useful for a dispersant of various pigments and the like, a scale suppressor, a cleansing builder, a thickener, a binder, a medicinal substrate for fomentations and poultices, and the like.SOLUTION: A poly(meth)acrylic acid partially neutralized product obtained by polymerizing a monomer mixture containing (meth)acrylic acid and (meth)acrylate salts and having 2,000,000-4,000,000 weight-average molecular weight and 1.0-1.3 molecular weight distribution represented by weight-average molecular weight/number-average molecular weight is provided.COPYRIGHT: (C)2008,JPO&INPIT【課題】水溶液での不溶解分が極めて少なく、水溶液における粘度が低く、また、経時変化も小さいという特徴を有し、各種顔料等の分散剤、スケール抑制剤、洗浄用ビルダー、増粘剤、バインダー、医薬用の湿布剤やハップ剤の基剤などに有用なポリ(メタ)アクリル酸部分中和物を提供する。【解決手段】(メタ)アクリル酸および(メタ)アクリル酸塩を含む単量体混合物を重合させて得られるポリ(メタ)アクリル酸部分中和物であって、重量平均分子量が200万~400万であり、かつ重量平均分子量/数平均分子量で表される分子量分散度が1.0~1.3であるポリ(メタ)アクリル酸部分中和物が前記課題を解決する。【選択図】なし
