| 摘要 |
PURPOSE:To obtain clear discolored symbols, in a temperature indicating sheet, in which microcapsules including a coloring component that is dissolved at a specified temperature and a discoloring agent are combined, by marking the required symbols when the sheet is used, and destructing the microcapsules. CONSTITUTION:Gelatin and the like are used as a film component. Microcapsules 4, which include a coloring agent 1 (e.g., crystal violet lactone) and a wax state material 2 (e.g., glycerol), which is dissolved at a specified temperature, are prepared. Then, a discoloring agent 3 (e.g., p-hydroxybenzoic acid methyl), which is contacted with the coloring agent 1 and yields discoloring, is applied on the outer surfaces of the microcapsules 4, and a temperature indicating sheet is prepared. When the sheet is used, the required symbols such as characters and figures are marked on the temperature indicating sheet by using metal stamps. When a specified temperature change is applied to this sheet, only the marked parts are discolored, and the clear discolored symbols can be obtained. |
