| 摘要 |
PURPOSE:To obtain a developer chargeable to uniform and intense positive potential, and capable of developing a negative electrostatic image and giving a high quality image, by incorporating fine silica powder rendered hydrophobic with a specified cationic type silane reactive with unsatd. amine. CONSTITUTION:Fine silca powder having 0.001-2mum primary particle diameter obtained by oxidizing silicon halide compd., such as SiCl4 in a vapor phase is coated with a cationic type and unsatd. amine-reactive silane, such as formula having formula I in which X is OH or a hydrolyzable group; R is 1-6C alkyl; n is 1-3; Q is a divalent hydrocarbon group, a divalent hydrocarbon group contg. O as -COC-, or formulae II-IV, or contg. N as R''N=; m is 1 or 2; Z is a divalent group conjugated with formula V, and combines with N through C-N bond; R'' is H or R; and Y is an acid anion. The obtained fine silica powder has 30-80 hydrophobic degree measured by methanol titration, and it is mixed with a binder resin and a coloring material, etc. to obtain a developer. |
