| 摘要 |
A process for the preparation of a gel for use as a cooling medium is provided which comprises the steps of casting an aqueous solution or suspension containing a polyvinyl alcohol having a degree of hydrolysis of not less than 95 mol % and a viscosity average polymerization degree of not less than 1500 into a mold having desired shape and dimensions, cooling the cast aqueous solution to a temperature of not higher than - (minus) 6 DEG C., and then dehydrating without thawing the cooled mass of the cast aqueous solution in vacuum until the percentage dehydration rate reaches not less than 5 wt %.
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