| 摘要 |
PURPOSE:To enhance whiteness and to make the storage stability of paper excellent by using a fluoran compound represented by formula I prepared by reacting a benzoic acid derivative represented by formula II and a diphenylamine derivative represented by formula III. CONSTITUTION:A fluoran compound is represented by formula I (wherein R is an n-propyl group or an n-butyl group) and can be suitably prepared by reacting a benzoic acid derivative represented by formula II and a diphenylamine derivative represented by formula III pref. in conc. sulfuric acid in the presence of a dehydrating condensation agent, for example, conc. sulfuric acid. conc. sulfuric acid to which fuming sulfuric acid is added, polyphosphoric acid, phosphorus pentoxide or anhydrous aluminum chloride and making the reaction solution alkaline. By this method, the solubility to capsule oil becomes high and the weatherability of a developed color image after color development is made excellent. |
