| 摘要 |
PURPOSE:To obtain a magnetic developer having a combination of development operability and superior image formation performance by adding the fine black TiO2 particles to the surface of fixable magnetic powder made of a compsn. obtained by dispersing magnetic particles into a fixing medium. CONSTITUTION:A fine magnetic powder, such as Fe3O4, Fe2O3, or ferrite, are mixed with a fixable binder medium in a weight ratio of 1:5-5:1 in the final state of compsn., they are kneaded, and pulverized or the mixture dissolved or dispersed in a volatile solvent is spray dried in a drying atm. The magnetic toner thus prepared is stirred and mixed together with a black TiO2 with a stirrer such aa a mixer to execute coating operation, i.e., coat the surface of the magnetic toner particles with the TiO2 powder. Further, the TiO2 powder may be buried into the surfaces of the magnetic toner particles by treating them in a hot air stream. |
