SALT-RESISTANT WATER ABSORBENT

摘要

PROBLEM TO BE SOLVED: To provide a salt-resistant water absorbent having excellent water absorptivity even for a water-based liquid containing metal ions of two or more valances. SOLUTION: The salt-resistant water absorbent consists of a water-absorbing resin prepared by reverse phase suspension polymerization of a monomer aqueous solution consisting of 50 to 90 mol% water-soluble ethylenic unsaturated monomers containing amino groups and 10 to 50 mol% acrylic acid having 40 to 100 mol% neutralization degree with alkali metals in the presence of a crosslinking agent, surfactant and water-soluble radical polymerization initiator.