| 摘要 |
PURPOSE:Hydrous gel of PVA useful as a cold insulant, especially as a cold insulant pillow, obtained by freezing an aqueous solution containing <= a fixed amount of a specific PVA to give hydrous gel, covering this hydrous gel with hydrous gel of a specific PVA having a freezing temperature lower than that of the hydrous gel. CONSTITUTION:>=5wt% aqueous solution of PVA having >=500 average polymerization degree and >=95mol% saponification degree is frozen to give hydrous gel having an arbitrary shape is covered with hydrous gel obtained by freezing >=5wt% aqueous solution of PVA having >=500 average polymerization degree and >=95mol% saponification degree, a freezing temperature lower than that of the hydrous gel, containing preferably an antifreezing agent (preferably propylene glycol), to give the aimed hydrous gel. |
