| 摘要 |
PURPOSE:To prevent the decrease in the quantity of electrostatic charge as a result of staining of carrier surface by a toner, etc. and the consequent deterioration of image quality even after continuous and repetitive use by coating the surface of the dry process carrier or the surface and pore inside thereof with a titanate coupling agent. CONSTITUTION:Ferrite powder, iron powder, Ni powder or the like which serves as a core is subjected to an immersion stirring treatment in an aq. soln., etc. of various titanate coupling agents of a monoalkoxy type, chelate type, a type improved in hydrolysis resistance by adding phosphite to tetraalkyl titanate and is then subjected to filtration and drying to form said a monomolecular layer on at least the surface of the core. The rate of coating is made within a 0.0001- 1wt% by the weight of the core. The core grain size is preferably within 20- 150mu average grain size. The dry process carrier which decreases carrier staining, has the stable quantity of electrostatic charge even under the high humidity and has a high rate of electrostatic charge by friction with the toner is thus obtd. |
