BLACK MAGNETIC PARTICULATE POWDER FOR BLACK MAGNETIC TONER AND BLACK MAGNETIC TONER USING THE BLACK MAGNETIC PARTICULATE POWDER

摘要

PROBLEM TO BE SOLVED: To provide a black magnetic particulate powder for a black magnetic toner excellent in dispersibility in a resin binder as well as in flowability and blackness. SOLUTION: The surface of magnetic iron oxide particulate powder having 0.055-0.95 μm average particle diameter is coated with an organosilane compd. formed from an alkoxysilane and fine carbon black particulate powder having 0.002-0.05 μm average particle diameter is struck to the formed coating of the organosilane compd. by 1-25 pts.wt. based on 100 pts.wt. of the iron oxide particulate powder to obtain the objective black magnetic composite particulate powder for a black magnetic toner.