Patent ID: 6638675
Filing Date: 2003-10-28
Classification: G03G,Y10S,Y10T

Abstract:
Black magnetic toner having a volume resistivity of 1.0Ã—1013 to 1.0Ã—1015 &OHgr;cm, comprising:a binder resin, and black magnetic composite particles comprising: magnetic iron oxide particles having an average particle diameter of 0.055 to 0.95 &mgr;m; 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: (1) organosilane compounds obtainable from alkoxysilane compounds, (2) polysiloxanes or modified polysiloxanes, and (3) fluoroalkyl organosilane compounds obtainable from fluoroalkylsilane compounds; and a carbon black coat formed on said coating layer comprising said organosilicon compound, in an amount of 1 to 25 parts by weight based on 100 parts by weight of said magnetic iron oxide particles.