| 摘要 |
<p>A hydrogel which has a water content of 20 to 92 weight % and which is stable and superior in mechanical properties is obtained by preparing a 3 to 25 weight % aqueous solution of a polyvinyl alcohol having a degree of hydrolysis not less than 95 mol% and a viscosity-average polymerization degree of not less than 1,500, pouring the aqueous polyvinyl alcohol solution into a desired shape of a vessel or a mold, freeze-molding the aqueous polyvinyl alcohol solution at a temperature lower than -6°C, thereafter dehydrating the molded article without thawing it until the dehydration percentage reaches 5 weight % or more and, if required, immersing the dehydrated product in water.</p> |
