| 摘要 |
PURPOSE:To enable the absorption of a light in a near infrared region to enable a reading with an optical character reader or a bar code reader and to reduce a surface color-forming, by using a specific compound as a leuco dye and using a specific compound as a surface color-forming inhibitor. CONSTITUTION:A compound used as a leuco dye is shown by a formula (1), and a compound used as a surface color-forming inhibitor is shown by a formula (2). In the formula (1), R1, R2, R3, and R4 are hydrogen or substd. or unsubstd. alkyl, R5 and R6 are hydrogen or substd. or unsubstd. phenyl, and R7 is substd. or unsubstd. alkyl, substd. or unsubstd. phenyl, or substd. or unsubstd. naphthyl. In the formula (2), R8 is substd. or unsubstd. alkyl, substd. or unsubstd. phenyl, or substd. or unsubstd. naphthyl. The sulfinate compound shown by the formula (2) is preferably added in the amount of 0.03-0.08pts.wt. per 1pts.wt. of the leuco dye. |
