| 摘要 |
PURPOSE:To offer the magnetic toner which has a sharp development characteristic distribution and can maintain picture quality from the start to the end of the service life of a developing machine even when a development system which supplements toner, cartridge by cartridge, is used by narrowing down the grading distribution of toner and increasing the sticking strength of external additives. CONSTITUTION:The single-component magnetic toner consists of toner particles containing binding resin and magnetic material particulates and silica particulates as the external additives. The toner particles need to have 6.5 - 11.5mum mean particle size. When the mean particle size is <=6.5mum, fine powder is too much and the developing performance deteriorates. When the mean particle size is >=11.5mum, the roughness of picture quality is large, the reproducibility of thin lines is inferior, and thickening is caused. Further, the toner particles need to have a grading distribution of a percentage of 12 particles of <=5mum particle size and consequently, a copy image of high image quality is formed even when copying operation is performed repeatedly. Further, initial high picture quality is maintained when the thickness of toner particulate surfaces of the silica particulates is <=0.05mum. |
