| 摘要 |
PROBLEM TO BE SOLVED: To obtain a water absorbent resin having a high absorbing magnification under no press. and besides a water-soluble componential amt. reduced, by adding a specific amt. of an aq. liquid to an undried, hydrous gel-like crosslinked polymer to thereby make it absorb, then by heating and drying. SOLUTION: An additional amt. of an aq. liquid is 20% or more relative to the whole wt, and pref. 85-100 wt.%. The upper limit of the additional amt. shall be 100,000 wt.% or less. A hydrous gel-like, crosslinked polymer may be one which is obtained by after-crosslinking an aq. soln. of an uncrosslinked water-soluble polymer, but it is pref. usable what is obtained by crosslinking and simultaneously polymerizing a monomer in an aq. soln. The monomer to be used is a ring-opening polymerizable monomer. The aq. soln. to be used is an aq. liquid which is substantially inert to the functional group on a water absorbent resin, e.g. an ion-exchanged water or the like. A temp. of the polymer on absorbing shall be 40-100 deg.C. And a drying temp. on heating and drying shall be 80-230 deg.C. The particle size of a powdery water absorbent resin, shall be decided according to the object so as to be within 10-2,000μm.
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