| 摘要 |
PROBLEM TO BE SOLVED: To widen a developable hue and to reduce the discoloration of an undeveloped color part at a time of optical fixing by forming two or more thermal color forming layers forming mutually different hues on a support and adding an oxidation color forming type leuco dye, an oxidizing agent and a photoreduction to one of the thermal color forming layers. SOLUTION: Two or more thermal color forming layers forming mutually different hues are formed on a support. An oxidation color forming type leuco dye composed of one kind of a compd. selected from 8-diethylamino-11-(2- methoxycarbonylphenyl)benzo [a] xanthene, 8-diethylamino-11-(2- butoxycarbonylphenyl)benzo [a] xanthene, and 8-diethylamino-11-(2- butoxycarbonylphenyl)benzo [a[ xanthene, an oxidizing agent and a photoreduction agent are added to one of the thermal color forming layers. By this constitution, a developable hue is widened and the discoloration of an undeveloped color part at a time of optical fixing can be reduced. |
