| 摘要 |
PROBLEM TO BE SOLVED: To provide excellent long-term storage stability of a color developed image by incorporating a thermal color developing layer containing colorless or pale dye precursor and developer for color developing in reaction with the precursor at the time of heating, and incorporating at least one type of organic compound represented by one member selected from formulae (I) and (I) to (VI) in the developer. SOLUTION: A developer contains at least one type of organic compound represented by a formula (I) [Y is one member selected from bivalent groups represented by formulae (II) to (VII). And, a thermal color developing layer contains leuco dye, aromatic organic compound (developer) represented by a formula (I) and sensitizer. It preferably contains organic or inorganic pigment or the like. Further, content of the dye in the developing layer is preferably generally 5 to 20 wt.% of dry weight of the developing layer. Content of the developer of the aromatic organic compound represented by the formula (I) is also generally preferably 10 to 50 wt.%. |
