To obtain a non-photosensitive composition which does not form a color under the action of heat or oxidation but forms a color under the action of an electrophilic agent by including a color precursor having a specified structure with an electrophilic agent which promotes its electrophilic reaction for forming a color or a precursor thereof.
This composition comprises a color precursor represented by formula II, such as one represented by formula I and an electrophilic agent which promotes its electrophilic reaction for forming a color or a precursor thereof. The electrophilic agent used is a compound represented by the formula: Z-CR41R42R43, formula III, or the like. In the formulae, Y is a substituent enhanced in its ability to leave when the electrophilic agent acts thereon; A1 and A2 are atomic groups which, together with Y and the carbon atom as a coupling site, form a coupler residue represented by formula IV or the like; R1 is a substituent; n is 0-4; R2 is hydroxyl or -n(R3)R4; R3 and R4 are each hydrogen or a substituent; X is a group which together with Y leaves under the action of the electrophilic agent to leave a color; Z is a halogen or the like; and R41 to R43 are each hydrogen or an electron-withdrawing group.
NAKAMURA TAKEMARE
ISHIKAWA SHUNICHI
