| abstract |
(57) [Summary] [PROBLEMS] To achieve high sensitivity by using a novel novel leuco dye, Even when a heat mode image recording method using a laser is used, recording can be performed with a low output laser that does not cause ablation, and an image recording medium that does not require a separate image receiving sheet is obtained. SOLUTION: The leuco dye represented by the formula (1) or a tautomer, in which a hydrogen atom capable of being moved by isomerization is substituted by a substituent P removed by the action of heat or an acid. In (1), (A) represents an atomic group necessary to form a nitrogen-containing hetero ring, (B) represents an atomic group necessary to form a 6-membered hetero ring, X represents an oxygen atom, Represents a sulfur atom or a nitrogen atom (having a hydrogen atom or a possible substituent). Embedded image |