| 摘要 |
PURPOSE:To obtain a high image density which is stable from an initial period without fogging and splashing and to reproduce the stable image which is not affected by age and the change of temp. and humidity by incorporating magnetic toner, pulverous positive chargeability silicic acid powder and tin oxide powder into a magnetic developer. CONSTITUTION:This positive chargeability magnetic developer consists of the magnetic toner, pulverous positive chargeability silicic acid powder and tin oxide powder. The pulverous silicic powder is effective when said powder is used at 0.01-20pts.wt. per 100pts.wt. toner. Said powder exhibits the positive electrostatic chargeability having excellent stability when the powder is added to the toner more particularly preferably at 0.05-5pts.wt. The tin oxide which can be adequately used is exemplified by thin (II) oxide SnO, thin (IV) oxide SnO2, etc. These metallic oxides are incorporated into the developer at 0.1-20wt%, more preferably 0.2-5wt% per 100pts.wt. toner. The grain size thereof is preferably <=5mu, more preferably in a 0.01-3mu range. |
