| 摘要 |
PURPOSE:To obtain a developed color image having strong absorption within a near infrared region, especially, within a range of 700 - 900nm and further showing black in the absorption within a visible region by using specific leuco dye. CONSTITUTION:A leuco dye represented by general formula (I) is used. In the formula (I), R1 - R6 are respectively represent the following. That is, R1 and R2 are a lower alkyl group, a cycloalkyl group, and aralkyl group or an aryl group and, further, may be mutually bonded to form a ring or bonded through -O- to form a morpholine ring, R3 is a hydrogen atom, a lower alkyl group, an alkoxy group or an aralkyloxy group, R4 and R5 are a lower alkyl group and R6 is a hydrogen atom, a lower alkyl group, an alkoxy group or a halogen atom. This dye can be easily synthesized by the dehydro-condensation of a ketone derivative represented by general formula (II) and an ethylene derivative represented by general formula (III) in the presence of a dehydro-condensation agent. |
