| 摘要 |
PROBLEM TO BE SOLVED: To provide a thermal history display material capable of accurately displaying the thermal history (temperature - time history) of an article by hue change.SOLUTION: The thermal history display material includes, in the following sequence: a thermal history display layer 20 in which an associative fluorescent dye having a fluorescent wavelength differing between an excimer state and a monomer state is fixed in a specific molecular dispersion state; and a first coating layer 10 disposed on one main surface of the thermal history display layer 20. The thermal history display layer 20 is a layer that discolors to a hue different from an initial hue when it is kept at a specific temperature or more at a certain time or more. The water vapor permeability of the first coating layer 10 is 1.0 g/mday atm or less at 40°C and at a relative humidity of 90%. |
