| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the occurrence of voids in a copied image, the sticking of a toner component to a photoreceptor and the scuffing of the photoreceptor by using an additive comprising titanium dioxide particles having a specified number average particle diameter obtained by vapor phase oxidation. SOLUTION: An additive comprising titanium dioxide particles having 0.1-0.7μm, preferably 0.3-0.6μm number average particle diameter obtained by vapor phase oxidation is mixed and added to toner particles. The titanium dioxide particles are obtained, e.g. by oxidizing titanium tetrachloride obtained by a chlorination method in the vapor phase. For example, rutile or other ore, coke, charcoal, etc., are mixed and crushed, chlorine is blown under heating at about 800 deg.C and TiCl4 is obtained by distillation and heated to about >=650 deg.C together with dry gaseous oxygen. The titanium dioxide particles are preferably surface-treated with a hydrophobic agent and the amount of the titanium dioxide particles is preferably 0.3-4.5 pts.wt. based on the amount of the toner particles.</p> |
