| 摘要 |
This cold-insulating tool is provided with a cold-insulating composition containing water, a precipitating component, a non-precipitating component, and a pH indicator, and is configured so that the precipitating component precipitates when the cold-insulating composition freezes and is a component not corresponding to the pH indicator, the non-precipitating component does not precipitate when the cold-insulating composition freezes and is a component not corresponding to the pH indicator, a change or presence/absence of color in the pH indicator is reflected from before to after freezing, and the cold-insulating composition changes color. |
