| 摘要 |
PURPOSE:To improve the triboelectrostatic chargeability, cleanability and environmental resistance of a developer by incorporating positive chargeable fine silica particles and tin oxide powder into the developer. CONSTITUTION:A coated carrier, nonmagnetic toner, the positive chargeable fine silica particles (A) and the tin oxide powder (B) are incorporated into the developer. The silica prepd. by subjecting the primary particles of the fine silica particles formed by vapor phase oxidation of a silicon halogen compd. to a surface treatment by an amino-modified silicone compd. (e.g.: amino modified silicone rubber) and adjusting the triboelectrostatic charge quantity thereof to a prescribed value can be used for the component A in this case. Tin oxide (II), tin oxide (IV), etc., are usable for the component B. The prescribed amts. of the components A, B having respectively desired average grain sizes and specific surface areas are added and mixed to and with the above-mentioned toner and are thereby adhered to the toner. The developer prepd. in such a manner is used. |
