| 摘要 |
PURPOSE:To provide a developing method having durability and stability against changes of the circumstances by incorporating a fine silica powder made hydrophobic in a magnetic developer. CONSTITUTION:A magnetic developer contains a product obtained by treating a fine silica powder produced by vapor phase oxidation of silicon halide with a siliane compd. having a cationic unsatd. amine function as shown by the general formula in which X is OH or a hydrolyzable group; R is 1-6C alkyl; n is an integer of 1-3; Q is a divalent hydrocarbon group alone or having O as -COC-, -(C=O)OC-, -(C=O)-, or -COH, or N as R'N=; R' is H, 1-6C alkyl or a heterocyclic org. compd. having an N-contg. ring; m is 1 or 2; Z is a divalent org. group having a double bond conjugated with -(C-R''= CH2) and Z combines with N through a C-N bond; R'' is H or 1-6C alkyl; and Y is an acid anion. This developer is held in a thickness smaller than the gap between a latent image bearing body and a developer carrying body on this body, and is transferred to the latent image bearing body to develop the image. Since, in this developing method, there is used a developer contg. said fine silica powder as a charge controlling component, the developer layer is uniformly triboelectrified, and an excess charge is allowed to leak through the fine silica powder to a proper satd. value, resulting in forming a stable developer layer. |
