| 摘要 |
PURPOSE:To obtain a toner which permits copying with stable image quality irrespective of the kinds of paper, the change in humidity, etc. by constituting the resin powder of high electric resistivity from two parts of different intensities of magnetism and chargeabilities. CONSTITUTION:Resin powder 1 of >=10<11>OMEGAcm resistivity which comprises the part 2 and part 3 of the resin powder contg. magnetic material, wherein the one part 2 has magnetism stronger than the other portion 3 and the part 2 and part 3 charge to mutually opposite polarities is used as a magnetic toner (fig. a). The above- mentioned resin powder is formed by mixing predetermined amounts of, for example, magnetic powder and molten resin, covering the mixture 3 of predetermined amounts of magnetic powder and molten resin on the surfaces of the resin powder 2 obtained by cooling and grinding said mixture to form resin powder 4, and grinding said powder to about half as shown by the line A-A then heat treating and classifying the powder. |
