| 摘要 |
<p>PURPOSE:To stably obtain high picture quality without causing embedding of a treating agent added on the toner even when the number of copies is increased, by controlling the dimensional ratio of aggregate of silica fine particles deposited on the toner surface to the average primary particle size of particles larger than the average particle size of the aggregate to a specified range. CONSTITUTION:This electrophotographic toner is treated to include external additive in a manner that the ratio r/R is controlled to 1-1/10, more preferably 1-1/6, wherein (r) is of the average particle size of silica fine particles (A) aggregating on the toner surface to the average primary particle size R of particles (B), for example, inorg. particles (C) or org. particles (D), larger than the average particle size (r) of the aggregate. The particles (B), for example (C) and (D) are well-known materials which satisfy characteristics required to the objective electrophotographic toner. The average particle size R of particles (B) is preferably 1/1000-1/10, more preferably 1/500-1/10 to obtain higher effect.</p> |
