Surface cross-linking methods of surface-crosslinked water-absorbent resin and water-absorbing resin

摘要

PROBLEM TO BE SOLVED: To provide a surface-cross-linked water-absorbing resin which can exhibit an excellent absorbing characteristic, even when the wt.% (resin concentration) of the water-absorbing resin is enhanced on the employment of the resin as a sanitary material or the like, to provide a new surface-cross-linking method for producing the resin, and to provide the use of the resin. SOLUTION: This surface-cross-linked water-absorbing resin characterized in that the thickness of a surface-cross-linked layer is 50 nm to 1,000 nm and/or in that the weight rate of the surface-cross-linked layer on the basis of the total amount of the resin is 0.3 to 3%.