| 摘要 |
PURPOSE:To stabilize electric charge of a toner even in a wide range of temp. and humidity and to maintain satisfactory quality of a picture image by providing a coating layer comprising 1-20wt.% Sb and residual wt.% tin oxide on the surface of TiO2 powder. CONSTITUTION:A developing agent comprising toner particles, carrier, and fine electroconductive powder is provided wherein the fine electroconductive powder consists of fine TiO2 powder having >=10m<2>/g specific surface area and coated with 10-70wt.% coating layer on the surface of the TiO2 particles, and said coating layer consists of 1-20wt.% Sb and residual wt.% tin oxide. Sticking and accumulation of toner on the surface of the carrier is inhibited in this developing agent even after using for a long time, so a satisfactory picture image as good as a picture image in the initial stage is obtd. Moreover, satisfactory picture images of high density are obtd. in all environmental conditions such as at low temp.-low humidity circumstance, or high temp.-high humidity circumstance, etc. |
