| 摘要 |
<p>PROBLEM TO BE SOLVED: To ensure stable image quality over a long period of time and to reduce the amt. of a toner discarded. SOLUTION: This developing agent used in an image forming method by a cleanerless system contains spherical toner particles and a magnetic carrier, and fine particles of an additive such as SiO2 made hydrophobic by treatment with a silane coupling agent such as hexamethylenedisilazane have been externally added to the surfaces of the toner particles at >=50% rate of surface coating. The magnetic carrier preferably has 20-50μm average particle diameter, 30-70emu/g saturation magnetization and >=10<14>Ωcm specific resistance. The toner particles are preferably obtd. by dispersing and suspending an oil phase contg. a bonding resin, a colorant and a solvent immiscible with water in an aq. phase and carrying out granulation.</p> |
