| 摘要 |
PURPOSE:To prevent an error in reading by a method wherein in a pressure- sensitive recording sheet forming a color image to be read by a red light of a predetermined wavelength, an electron donative dye is made of a diazaphthalide derivative shown by a specific formula, and an electron accepting color developer is made of a metallic salt of an aromatic carboxylic acid. CONSTITUTION:As a colorless electron donative dye to be contained in a dye layer, a diazaphthalide derivative shown by a formula is used. In the formula, R<1>-R<4> independently represent alkyl group that can be substituted by alkoxyl group, cycloalkyl group, aralkyl group that can be substituted by alkyl group, alkyl group, alkoxyl group, and aryl group that can be substituted by substd. amino group; R<1>, R<2> or R<3>, R<4> bonded to N may form a 5-, 6-, or 7-member ring that can have substituent; and R<5> and R<6> independently represent alkyl group that can be substituted by alkoxyl group. As an electron accepting color developer, a metallic salt of an aromatic carboxylic acid, such as a salicylic acid, is used. |
