| 摘要 |
PURPOSE:To enhance not only the light fastness and water resistance of a color forming body but also developed color density, by preparing a coupler for a leuco dye by using a salicylic acid derivative represented by a specific general formula as an effective component. CONSTITUTION:A coupler for a leuco dye containing a salicylic acid derivative represented by formula I [wherein at least one of R1-R4 is a group represented by formula II (wherein R5 is hydrogen or a methyl group) and the remainder thereof is hydrogen, an alkyl group, a cycloalkyl group or an aryl group, X is hydrogen or a divalent or more polyvalent metal and n is 1 when X is hydrogen and a valency of the polyvalent metal when X is the polyvalent metal] as an effective component is prepared. This coupler for the leuco dye is used alone or in a mixed state or used along with other coupler to be dispersed in a binder and the resulting dispersion is applied to a support to obtain a coupler sheet. |
