| 摘要 |
PROBLEM TO BE SOLVED: To provide excellent image storage stability without mixed color and without bleeding by adopting the same sulfone compound as electron acceptive compounds contained in low and high temperature color developing layers. SOLUTION: 3,3'-diallyl-4,4'-dihydroxydiphenylsulfone of sulfone compound is preferably used, and may be accompanied with other sulfone compound. To obtain a color developed image having excellent clarity and image storage stability, it is desirable that both high and low temperature color developing layers each contain 1.2 pts.wt. or more of total electron acceptive compound amount to 1 pt.wt. of total electron donative dye precursor contained in each layer. For the purpose of improving strengths of both the high and low temperature layers, a binder can be used. As additive for regulating color developing sensitivity, sensitizer can be contained in the developing layer. |
