| 摘要 |
PROBLEM TO BE SOLVED: To provide a sealing type reversible thermal discolorable indicator in which color fastness to light is remarkably improved, the discoloration function of a reversible thermal discoloration layer can be lasted over a long period, and the thermal discoloration function of a reversible thermal discolorable indicator repeatedly performing color developing and reducing can be maintained over a long period of time.SOLUTION: A sealing type reversible thermal discolorable indicator 1 is obtained by enclosing, in an oxygen low permeable sealing body 4 in which at least an indication face has transparency: a reversible thermal discolorable indicator 2 which is provided, on a supporting body 21, with a reversible thermal discoloration layer 22 including a reversible thermal discolorable material at least made of (a) an electron-donative coloration-type organic compound, (b) an electron-acceptive compound and (c) a reaction medium controlling the color reactions of the (a) and (b); an oxygen absorber 3; and an oxygen detecting agent capable of visually recognizing oxygen concentration. |
