| 摘要 |
An object of the present invention is to provide an aqueous poly(meth)acrylic acid (salt) solution having high dispersibility of inorganic substances and demonstrating dispersibility having sufficient stability over time, and a process for preparing the same. The present invention relates to an aqueous poly(meth)acrylic acid (salt) solution comprising a poly(meth)acrylic acid (salt) having a weight average molecular weight of 1000 to 10000 polymerized in the presence of a phosphorus compound containing hypophosphorous acid (salt), wherein the phosphorus compound contains 0 to 0.3% by mass of a phosphorous acid (salt) based on 100% by mass of the phosphorus compound, and the aqueous poly(meth)acrylic acid (salt) solution contains 0 to 10000 ppm of an inorganic anion; and a process for preparing an aqueous poly(meth)acrylic acid (salt) solution comprising the step of polymerizing a monomer in an aqueous solvent in the presence of a phosphorus compound containing hypophosphorous acid (salt), wherein the monomer contains a (meth)acrylic acid (salt) as an essential component, the phosphorus compound contains 0 to 0.3% by mass of a phosphorous acid (salt) based on 100% by mass of the phosphorus compound, the poly(meth)acrylic acid (salt) has a weight average molecular weight of 1000 to 10000, and the aqueous poly(meth)acrylic acid (salt) solution contains 0 to 10000 ppm of an inorganic anion. |
