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AssigneeNippon Shokubai Co., Ltd.
InventorsSumio Okuda, Syuji Kanzaki, Kunihiko Ishizaki, Shinichi Fujino, Kozo Nogi
Estimating the term…
Provided is a method which does not require alteration of the raw materials or high capital investment, and improves and stabilizes the physical property (for example, liquid permeability) of a water absorbent resin by means of a simple technique. A method for producing a water absorbent resin is disclosed, which method includes a polymerization step of polymerizing an aqueous solution of acrylic acid (salt) to obtain a water-containing gel-like crosslinked polymer; a drying step of drying the water-containing gel-like crosslinked polymer to obtain a water absorbent resin powder; a classification step of classifying the water absorbent resin powder; and a surface crosslinking step of surface crosslinking the water absorbent resin powder, wherein in the classification steps that are carried before the surface crosslinking step and/or after the surface crosslinking step, the stretch tension (tension) of the metal sieve mesh used in the classification step is from 35 [N/cm] to 100 [N/cm].
1-29. (canceled)
A method for producing a water absorbent resin comprising:
A method for producing a water absorbent resin comprising:
Dependencies are inferred from the claim text.