| 摘要 |
PURPOSE:To obtain a recording material suitable for the reading of OCR using a light source having a light emission wavelength in the region of 750-850nm by using a specified phthalide compound as the electron-donating leuco colorant. CONSTITUTION:A recording material using a color reaction of an electron- donating leuco colorant with an electron-accepting color developer, wherein a phthalide compound of formula I (wherein R<1> is 4-8C alkyl) is used as the electron-donating leuco dye, or alternatively a combination of the phthalide compound of formula I with a fluoran compound of formula II [wherein R<1> is as defined above; R<2> and R<3> are each alkyl, alkoxyalkyl, cycloalkyl or (substituted) phenyl; R<4> is H, alkyl, alkoxyl or Cl; and R<5> and R<6> are each H, alkyl, Cl, F or trifluoromethyl) is used as the electron-donating leuco dye. This material is suitable for the reading of OCR using a light source having a light emission wavelength in the region of 750-850nm. |
