| 摘要 |
PURPOSE:To form a developed color image having strong absorption within a near infrared region, especially, within a range of 700 - 1,000nm by using a specific leuco dye. CONSTITUTION:A leuco dye is represented by general formula (I) (wherein R1 is a hydrogen atom, a halogen atom or a dialkylamino group, R2 and R3 are a lower alkyl group, R4 is a hydrogen atom, a halogen atom, a lower alkyl group, an alkoxy group or a dialkylamino group, formula II is a benzene ring or a naphthalene ring, B is a group represented by formula III wherein R5 and R6 are an alkylene group, R7 is a lower alkyl group and n is 0 - 4). This dye can be easily synthesized by the dehydro-condensation of a benzophenone derivative and a butadiene derivative in the presence of a dehydro-condensation agent. |
