| 摘要 |
PURPOSE:To obtain capsule toner for stabilizing picture quality and having a high fixing property by uniforming the electrostatic charge/weight ratio of the capsule toner obtained by sealing pressure fixing cores having approximately spherical shapes into a thin film hard shell within grain distribution. CONSTITUTION:To obtain the capsule toner, components containing spherical wax or the like are distributed with 10-14mum average grain size and soft pressure fixing cores with about 1-40mum grain size are formed. The cores having <4mum and >=20mum grain size e.g. are cut out by an air classifier or the like and the cut-out toner is divided into plural classes by the air classifier or the like. Prior to capsule formation, grains such as silica are adhered to the surfaces of cores. At that time, the number of adhering grains to the cores in the smaller distribution side A is set up larger than that of the larger distribution side B and then the hard shell is attached, so that the smaller grain size side A is rougher than the larger grain size side B. Consequently, the contacting area with the side such as a developing sleeve receiving frictional electrification of toner is changed and the relation between the electrostatic charge/weight ration q/m and the radius (r) of toner in the same shape is not fixed, so that q/m variation is reduced and a stable image can be obtained. |
