| 摘要 |
PURPOSE:To rapidly form a color at low temp. by using a specific fluoran compound is a recording material as a color forming compound. CONSTITUTION:A fluoran compound represented by formula (I) is used as a color forming compound. This compound can be prepared by reacting a benzoic acid derivative represented by formula (II) and a diphenylamine derivative represented by formula (III) in the presence of a dehydrating condensation agent, for example, conc. sulfuric acid, fuming sulfuric acid, phosphorus pentoxide or anhydrous aluminum chloride and making the reaction solution alkaline. Dehydrating condensation reaction is usually performed at 0-100 deg.C for several hr - 100hr. The benzoic acid derivative represented by the formula (II) can be prepared by reacting 3-N-n-butyl-N-sec-butylaminophenol and phthalic anhydride in a solventless state or in a solvent such as benzene, toluene or xylene. In the formula (III) representing the diphenylamine derivative, R is a lower alkyl group such as a methyl or ethyl group. |
