To provide a thermal recoding material having a high coupling speed and being excellent in coloring properties and stable.
The thermal recording material has on a substrate a recording layer which contains a diazo compound expressed by general formula (1) and a coupler coloring in reaction with the diazo compound and expressed by a general formula (2) or the like. [R1 and R2 denote respectively hydrogen, a substituted or non-substituted alkyl group or a substituted or non-substituted aryl group, R3 the hydrogen, the substituted or non-substituted alkyl group, the substituted or non-substituted aryl group, a substituted or non-substituted alkoxy group, a substituted or non-substituted aryloxy group, a substituted or non-substituted alkylthio group, a substituted or non-substituted arylthio group, a halogen atom or a substituted amino group and X an acid anion. X1 denotes oxygen, sulfur or an imino group, Y1 and Z1 a carbon, oxygen, nitrogen or sulfur atom independently respectively and L1 a group separable on coupling with the diazo compound.].
YANAGIHARA NAOTO
TAKEUCHI YOSUKE
TSURUMI MITSUYUKI
