| 摘要 |
PURPOSE:To provide the suitability for reading optical characters in the near infrared region and to prevent the fading of a recording image under moistened, heated, and light-irradiated conditions, by containing a specific chromeno compound as a color-forming substance. CONSTITUTION:A thermal recording body contains at least one of chromeno compounds shown by formula (I), wherein G represents a formula 2 or 3, and R1-R4 represent each hydrogen atom, substd. or unsubstd. satd. alkyl, substd. or unsubstd. unsatd. alkyl, substd. or unsubstd. cycloalkyl, substd. or unsubstd. aralkyl, and substd. or unsubstd. aryl. Symbols R5-R11 represent each hydrogen atom, substd. or unsubstd. satd. alkyl, substd. or unsubstd. unsatd. alkyl, substd. or unsubstd. aralkyl, and substd. or unsubstd. aryl. For benzene rings A and B each, halogen atom, alkyl, alkoxyl, and substd. or unsubstd. amino may be substituted. |
