| 摘要 |
PROBLEM TO BE SOLVED: To provide a two-component developer that suppresses density variation of formed images even if toner consumption per recording medium varies, as compared with the case where a carrier whose surface energy is in a range and an external additive whose shape factor and number average particle size are in respective ranges are not included and the relationship between an abundance ratio of the external additive on a toner surface and that on a carrier surface does not satisfy following expression (1). SOLUTION: The two-component developer includes a toner, a carrier whose surface energy is 23-37 dyne/cm, and an external additive whose shape factor SF1 is 130-150 and whose number average particle size is 80 nm to 1μm, wherein an abundance ratio A of the external additive on a toner surface and an abundance ratio B of the external additive on a carrier surface satisfy the relationship of expression (1): 0.04≤B/A≤0.4. COPYRIGHT: (C)2011,JPO&INPIT |
