| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cold insulator with which foods, etc., can be kept cool in an ordinary-temp. atmosphere and which is repeatedly usable and has a beautiful appearance. SOLUTION: A main cold insulator body 2 is a rectangular flat molding of an aqueous gel containing a polyvinyl alcohol and a boric acid compound. The body 2 is covered with a synthetic resin film 3 preferably made of an ethylene/vinyl acetate copolymer or a saponified copolymer derived therefrom. The polyvinyl alcohol preferably has a degree of saponification of 93-98mol%. The aqueous gel has a polyvinyl alcohol content of preferably 15-40wt.%. Preferred examples of the boric acid compound are salts of polybasic boric acids and hydrates of the salts. |
