| abstract |
PROBLEM TO BE SOLVED: To provide an indicator whose color tone changes with the passage of time at a temperature of about 60 ° C., and which is suitable for managing, for example, a temperature / time history of a beverage or the like. An indicator has a recording layer on a substrate, the surface of which changes in color according to the history of temperature and elapsed time. The recording layer contains one or more basic dyes and a developer. And an indicator characterized in that at least one of the basic dyes is a blue dye having at least one maximum absorption wavelength in a wavelength range of 560 to 750 nm, and an adhesive on one surface of the indicator. Management that detects that the managed product has been stored at or above the managed temperature for a specified period of time or at a temperature that exceeds the managed temperature, based on the label having the agent layer and the color of the indicator or label attached to the surface of the managed product. Temperature / time history detection method for the target product. [Selection diagram] None |