PURPOSE: To enable to apply a recording material to an optical character (or mark) reader, by a method wherein a specified phthalide derivative is jointly used in a specified proportion to a dye, and the difference between the light reflectance of a recorded image before color development and that after the color development is specified, in a recording material comprising a basic dye and an electron-acceptive substance.
CONSTITUTION: A phthalide derivative of the formula, wherein each of R1 and R2 is an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or the like, R3 is a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an acyloxyl group or the like, R4 is a hydrogen atom or an aralkyl group, and each of aWd is a carbon atom, is jointly used in an amount of 5W80wt% of the amount of the dye. A recorded image, the color of which is developed by the electron-acceptive substance, is so produced that the difference between the light reflectance thereof before color development and that after the color development becomes not less than 55% over a wavelength range of 580W880nm.
| JPH04371887 | THERMAL RECORDING MATERIAL |
| JP2009067048 | THERMAL RECORDING BODY |
| JP3575873 | THERMAL RECORDING MATERIAL |
KANDA NOBUO
NOGUCHI AKIO
TAKAYAMA YUKIO
| JPS57167979A | 1982-10-16 |