| abstract |
(57) [Abstract] (with correction) [Problem] To provide a water absorbing / water retaining agent which is hardly affected by polyvalent metal ions and has a small decrease in absorption even in an aqueous solution containing a large amount of polyvalent metal ions. SOLUTION: A water-soluble mono (meth) acrylate having a hydroxyl group (a) is 40 to 99% by weight, (meth) acrylic acid (alkali metal salt) (b) is 1 to 60% by weight, and a crosslinking agent (c) is 0.1% by weight. Water-absorbing or water-holding agent comprising a water-absorbing resin (A) containing 00001 to 3% by weight and, if necessary, other water-soluble ethylenically unsaturated monomer (d) in a range not exceeding 10% by weight. . |