| 摘要 |
PROBLEM TO BE SOLVED: To obtain a heat-sensitive recording unit having high whiteness and stability of colored image by including a sheet-like substrate and a heat-sensitive colorless or pale dye precursor and a coloring layer comprising a developer composed of a specific compound. SOLUTION: This heat-sensitive recording unit comprises (A) a sheet-like substrate, (B) a colorless or pale dye precursor formed on at least one surface of the above substrate, (C) a heat-sensitive coloring layer comprising a developer and capable of reacting with the dye precursor under heating to color the dye precursor. The developer of the component C comprises at least one kind of compound of the formula (R1 is methyl or an aromatic group which may be substituted with chlorine; R2 is >=3C divalent organic group) [e.g. 1,3- trimethylene bis(4-(p-toluenesulfonylaminocarbonylamino)benzoate)]. The compound of the formula is obtained by reacting, e.g. trimethylene bis(4- aminobenzoate) with p-toluenesulfonyl isocyanate. |
