| abstract |
Black magnetic toner comprising: n a binder resin, and black magnetic composite particles comprising: n magnetic iron oxide particles having an average particle diameter of 0.055 to 0.95 μm; n a coating layer formed on the surface of said magnetic iron oxide particles, comprising at least one organosilicon compound selected from the group consisting of: n (1) organosilane compounds obtainable from alkoxysilane compounds, n (2) polysiloxanes or modified polysiloxanes, and n (3) fluoroalkyl organosilane compounds obtainable from fluoroalkylsilane compounds; and n a carbon black coat formed on said coating layer comprising said organosilicon compound, in an amount of 1 to parts by weight based on 100 parts by weight of said magnetic iron oxide particles. n Such a black magnetic toner can be free from being deteriorated in electric resistance due to the existence of the carbon black coat, and as a result, is suitable as a high-resistance or insulated magnetic toner. |