DISCOLORABLE TIME LAPSE INDICATOR AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a discolorable time lapse indicator that can exhibit discoloration performances in response to environmental conditions (temperature and humidity) for a long term and to a lapse of time and can undergo distinct discoloration. SOLUTION: There is provided a discoloration time lapse indicator having a discolorable ink layer that discolors in response to temperature and/or humidity and to a lapse of time and a non-discolorable ink layer on a substrate, wherein a separation layer separates the support from the discolorable ink layer and the non-discolorable ink layer, the discolorable ink layer and the non-discolorable ink layer are formed in such a manner that at least a part or the whole of the discolorable ink layer is exposed to atmospheric air.