| 摘要 |
PURPOSE:To obtain excellent color-developing capacity by forming a colorless or light-colored dye precursor formed onto at least one surface of a sheet base body and a thermal color-developing layer containing a developer in specific general formula being reacted with the dye precursor under heating and color- developing the precursor. CONSTITUTION:A compound in formula 1 (R<1> and R<2> represent a hydogen atom, a lower alkyl group, an aryl group, an aralkyl group or a halogen atom respectively independently, (m) and (n) the integers of 1-5 mutually indenpendently and respectively and R' and R'' hydrocarbon groups forming cyclic structure together with a part of a benzene ring, with which each of R<1> and R<2> bond, and may form polynucleus aromatic ring structure together with the benzene ring) functions as a developer when a color-developing image is shaped by utilizing the color reaction of a colorless or light-colored dye precursor and the developer capable of color-developing under heating with the dye precursor. The compound in formula 1 has an amino group activated by an adjacent sulfonyl group, thus displaying intense color-developing capacity in the dye precursor. |
