A reversible thermochromic composition comprises (a) an electron-donating color-developing organic compound, (b) at least one electron-accepting compound selected from alkoxyphenols compounds of the formula
and (c) a compound serving as a reaction medium capable of causing a reversible electron-donating/accepting reaction attributable to components (a) and (b).
This composition has a reversible metachromatic function; in one aspect, it presents a color-developed state when heated from a color-extinguished state and presents the color-extinguished state when cooled from the color-developed state; in another aspect, it begins to develop color during the course of being cooled after having been heated, color development having been triggered by the temperature rise when being heated in a color-extinguished state, and returns to the color-extinguished state after presenting a maximum developed-color density.
一种可逆热致变色组合物包括(a)一种电子捐赠显色有机化合物,(b)至少一种选自式烷氧基
苯酚化合物的电子接受化合物
(c) 一种作为反应介质的化合物,该化合物能够引起可归因于成分 (a) 和 (b) 的可逆电子捐赠/接受反应。
这种组合物具有可逆的偏色功能;一方面,当它从褪色状态加热时呈现显色状态,当从显色状态冷却时呈现褪色状态;另一方面,它在加热后冷却过程中开始显色,显色是在褪色状态加热时由温度升高触发的,并在呈现最大显色密度后返回褪色状态。