| 摘要 |
PURPOSE:To improve sensitivity, potential stability during long-term use, and stability of a dispersion fluid by drying a disazo pigment represented by the formula through the spray drying method, then, dispersing it and forming it into a film. CONSTITUTION:A photoconductive org. pigment used here is represented by the formula in which R1 is lower alkyl; R2 is H, halogen, lower alkyl, or lower alkoxy; R3 is H, Cl, or methyl; Z is O or S; and X is a residue condensing with a benzene ring to form a naphthalene, anthracene, carbazole, dibenzofuran, or benzocarbazole. This disazo pigment can be easily synthesized by tetrazotizing a corresponding diamine by the normal method, allowing a corresponding coupler to cause azocoupling reaction in the presence of alkali, or once separating said tetrazonium salt of diamine in the form of borofluoride salt or zinc chloride complex salt, or the like, and then, causing the azocoupling reaction with the coupler in a proper solvent. The spray drying method permits the fine spherical dry powder of the disazo pigment to be obtained without receiving excess heat. |
