| 摘要 |
PURPOSE: To obtain a time-indicating material for clearly indicating the lapse of a prescribed time at a prescribed temperature or the cumulative value of temperature and time by the change of color. CONSTITUTION: This material indicating the time or the cumulative value of temperature and time as a color change is composed of a 1st layer containing the following agent A supported in a supporting member, a 2nd layer containing an agent B in a state free from contact with the agent A and a 3rd layer for diffusing the agent A or the agent B and laminated between the 1st layer and the 2nd layer. The agent A and the agent B are a combination of a free radical generator and a colorant and/or colorant precursor changing its color by reacting with a free radical, e.g. a phenothiazine-based color-developing pigment. |
