| 摘要 |
PURPOSE:To stabilize frictional electrostatic charge with lapse of time and to obtain substantial and stable density in long-term use by allowing pulverous conductive powder to exist at the boundary between a core material and shell material. CONSTITUTION:The pulverous conductive powder is allowed to exist near the surface of the core material. The shell material formed n the surface of the core material is thin and therefore the pulverous conductive powder is partly exposed to the surface or even if said powder is not exposed, the adequate electric discharge characteristic is maintained through the thin core material when the pulverous conductive powder is made to exist at the boundary between the core material and the shell material in the above-mentioned manner. The degree of said discharge characteristic is optionally controllable with the thickness of the shell material to be formed. The capsule toner provided with the adequate electric discharge characteristic has the stable frictional electrostatic charge without an excessive increase even after a long period of a developing operation. The developing characteristic stabilizes accordingly. The copy image having the substantial density and stable quality is thus obtd. even after long- term use. |
