| 摘要 |
PURPOSE:To improve flowability and to obtain high and stable image densities and to lessen fogging by adding a specific ratio of a coupling agent at the time of compounding magnetic powder, resin and charge control agent. CONSTITUTION:The titanate coupling agent having an alkoxy group is added at 0.05 to 0.45 pts. wt. per 100 pts. wt. compd. at the time of producing the magnetic toner by compounding the magnetic powder, resin and charge control agent to form the toner. The magnetic powder having 0.01 to 10 mum, more particularly 0.05 to 3 mum average grain size is more preferably. The magnetic powder has 70 to 250 Oe, more preferably 75 to 150 Oe coercive force at 5,000 deg. Oe. The magnetic powder has 50 to 100 emu/g, more particularly preferably 70 to 90 emu/g saturation magnetization at 5,000 Oe. The amt. of the resin to be added is 30 to 80 wt.%, more particularly preferably 40 to 70 wt.%. The content of the charge control agent is 1 to 5 wt.%, more particularly preferable at 0.5 to 2 wt.%. The particle size of the toner is preferably specified to 3 to 30 mum. |
