| 摘要 |
PURPOSE:To obtain a polymer excellent in water solubility and storage stability by placing a water-contg. substance comprising a (meth)acrylic acid (salt) polymer having a specified degree of neutralization in a specified thickness on a sheet, thermally drying and cooling the substance, and separating it from the sheet. CONSTITUTION:This (meth)acrylic acid (salt) polymer is produced by polymerizing a (meth)acrylic acid (salt) monomer in an aqueous soln., neutralizing the polymn. product so that up to 50mol% of acid groups in the product are neutralized, placing the product in a thickness of 0.5-10mm on a sheet, thermally drying the product at 80-230 deg.C to remove water, cooling the resulting polymer to 60 deg.C or lower, and separating the polymer from the sheet. The obtd. polymer is excellent in water solubility and storage stability, giving, even when dissolved in water after storage, a soln. which does not undergo decrease in thickening effect. |
