| 摘要 |
PURPOSE:To enance light fastness before use and characteristics of a preparation by using a specific compound as an electron donating leuco dye. CONSTITUTION:In a recording material utilizing color development due to the contact of an electron donating leuco dye with an electron acceptive compound, a compound represented by formula (wherein R1 is a 5-18C alkyl group, each of R2 and R3 is H, an alkyl group or an alkyl group, R4 is H or an alkyl group, R5 is H or an alkyl group and a ring A is a pyridine ring or a pyradine ring) is used as the electron donating leuco dye. As said leuco dye, there is 3-(1-n- amyl-2-methylindol-3-yl)-3-(1-methylpyrro-2-yl)-4- or -7-azaphthalide. |
