| 摘要 |
PURPOSE:To obtain an hig-definition electrophotographic developer with a long life and a lower toner consumption quantity by mixing a high electric resistant toner having a specified molecular weight and a high electric resistant carrier. CONSTITUTION:This developer is composed of a binder resin consisting of a styrene acryl copolymer with 5,000-20,000 number average molecular weight and with 1,500,000 weight average molecular weight, the toner incorporating 10-15wt.% of carbon black in the total toner, having 10<11>-10<12>OMEGA.cm volume resistance and the resin coated carrier with >=10<12>OMEGA.cm a volume resistance. In case where the content of the carbon black is <=10wt.%, the triboelectric volume between the toner and the carrier is increased the time of copying and the toner spent and the sleeve sticking to the toner are generated. On the other hand, in case where it is >=15wt.%, the volume resistance is lowered and the fogging at the base is generated. Thus the high-definition electrophotographic developer with a long life and a lower consumption quality is obtained. |
