PURPOSE: To obtain a recording material having superior properties such as melting, coloring of a compound itself, developed color, color development, absorbance and image stability by adding a specific divinylphthalide as a coloring agent.
CONSTITUTION: The subjected recording material contains a compound of the formula I as a coloring agent. A divinylphtalide compound expressed in the formula I is almost colorless itself and highly stable in an atmosphere. In addition, the compound undergoes no sublimation and spontaneous color development (texture fog), and is melted into an organic solvent quite smoothly. The subject recording material becomes black quickly with a developer and also shows a highly light-resistant and wet-proof color-developed image. Further, a color- developed image shows a high absorption in a 700W1,000nm range in addition to a visible part, so that data can be read by an optical character reader or a bar code reader using a near infrared ray. The developer is used as one for ordinary black color recording material and other infrared reader recording material. As recording materials, pressure sensitive copying paper, thermal recording paper, energized thermal recording paper, color-development thermal transfer recording paper and temperature indicating material are used.
FUTAEDA SEIICHI
GENDAI KAZUHIKO
TSUNEMITSU KATSUHIKO
