| 摘要 |
PURPOSE:To obtain a phthalide compound which, when reacted with a developer, comes to have sufficient absorption in a nearinfrared region but have no or little absorption in the visible region by reacting an ethylene compound with a benzoic acid derivative in the presence of a dehydration/condensation agent. CONSTITUTION:An ethylene compound represented by formula I is reacted with a benzoic acid derivative represented by formula II in the presence of a dehydration/condensation agent to obtain a desired phthalide compound represented by formula III. In the formulae, A is a substituent represented by formula IV (wherein R1 is H, an alkyl, an alkoxy, or a halogen atom and n is 1-3); B is a substituent represented by formula V; R2 is an alkyl or aryl; R3 is an alkyl; R4 and R5 each is an alkyl or an optionally substituted phenyl; R6 is H, an alkyl, or an alkoxy; and B' is a substituent represented by formula VI. A near-infrared absorbent comprising this phthalide compound and a recorded image formed on a recording material containing the compound show intense absorption in a near-infrared region but show little absorption in the visible region. Although this absorbent looks colorless or lightly colored, it has a high ability to absorb near-infrared light. |
