Dry toner, toner production process, image forming method and process cartridge

摘要

A toner showing a high transferability and suitable for use in cleanerless image forming system is formed of toner particles comprising at least a binder resin and magnetic iron oxide. The toner is characterized by a specific circularity distribution relative to its weight-average particle size and a controlled degree of surface-exposed magnetic iron oxide providing an extract solution with hydrochloric acid showing an absorbance of 1.0-2.5 at a wavelength of 340 nm. The toner is suitably produced by a production system including a rotary mechanical pulverizer and a one-pass surface treatment apparatus for continuously applying a mechanical impact force to pulverized toner particles therein.