| 摘要 |
PROBLEM TO BE SOLVED: To provide a preparation method of a superabsorbent polymer hydrogel which has superabsorbency, is low in toxicity, shows biodegradability and is producible at low costs.SOLUTION: A production method of a superabsorbent polymer hydrogel includes (a) a step of preparing an aqueous solution containing a hydrophilic polymer and a polycarboxylic acid or its anhydride, with the polycarboxylic acid selected from 4-12C dicarboxylic, tricarboxylic and tetracarboxylic acids and (b) a step of cross-linking the hydrophilic polymer with the polycarboxylic acid and keeping the solution of the step (a) under such conditions as to be suitable for production of a polymer hydrogel. The polymer hydrogel has a swelling ratio of 10, preferably a swelling ratio of higher than 50, and most preferably a swelling ratio of higher than 100. The hydrophilic polymer is one or more selected from polysaccharides including substituted celluloses, substituted dextrins, and substituted starches, or polyallyl alcohol, polyvinyl alcohol, etc. |
