| 摘要 |
PURPOSE:To obtain a long-life two-component developer having superior stability of picture quality which provides high-speed development, by setting the electric resistance of pulverulent toner to >=10<11>OMEGA.cm and the frictional charge quantity of the developer to <=8muc/g. CONSTITUTION:As an example of implementation, a 60pts. styrene butyl acrylate copolymer and 40pts. magnetite are milled for 30min by three roll mills of 160 deg.C roll temperature and after cooling, prescribed comminution is carried out to obtain magnetic toner. The electric resistance of this toner is 8X10<15>OMEGA.cm, and the frictional charge quantity -7.0muc/g. Then, the developer obtained by mixing 5pts. magnetic toner with a 95pts. magnetic carrier is used to continuously develop 30,000 sheets by a prescribed copying machine at a copying speed of 10 sheets per minutes, so that clear copied pictures free from a change in picture quality can be obtained. Thus, the developer having superior stability of picture quality can be obtained which provides high-speed development without any trouble regarding its life. |
