| 摘要 |
PURPOSE:To obtain a spherical magnetic toner which has a high image density, forms a sharp image, and has excellent durability and sharp grain size distribution by treating the toner with a prescribed org. titanium compd. to form the magnetic toner having the electrostatic frictional charge characteristic of a prescribed triboelectric-value by a suspension polymn. method from a prescribed monomer system. CONSTITUTION:The magnetic particles are treated with 0.5-10pts.wt. org. titanium compd. per 100pts.wt. magnetic particles and the magnetic toner having the frictional charge characteristic of >=5muc/g triboelectric-value by the suspension polymn. method consisting of the monomer system having at least an offset preventive agent consisting of a long chain satd. and/or unsatd. hydrocarbon, polymerizable monomer and polymn. initiator. An org. compd. contg. a reactive group, hydrophobic group or hydroxyl group which can react with the magnetic particles, more preferably trivalent pyrophosphate titanium compd. is used as the titanium compd. to be used. The treatment of the titanium compd. is executable by a wet or dry process. |
