Abstract: In a toner comprising toner particles which comprise toner base particles containing at least a binder resin and a magnetic material, and inorganic fine particles, the toner base particles have been obtained through a pulverization step; and, the toner base particles having a circle-equivalent diameter of from 3 ?m or more to 400 ?m or less as measured with a flow type particle image analyzer have an average circularity of from 0.935 or more to less than 0.970; and the toner base particles have an average surface roughness of from 5.0 nm or more to less than 35.0 nm as measured with a scanning probe microscope. The toner can enjoy less toner consumption per sheet of images, can achieve a long lifetime in a smaller quantity of toner, and has superior developing performance in any environment.

Abstract: In a toner having a polyester resin as a binder resin component, and a colorant, the toner contains (a) in the binder resin component, from 20.0% by weight to 65.0% by weight of a tetrahydrofuran-insoluble matter A1 in 6-hour extraction and from 35.0% by weight to 80.0% by weight of a tetrahydrofuran-soluble matter A2 in 6-hour extraction, (b) in the binder resin component, from 10.0% by weight to 30.0% by weight of a tetrahydrofuran-insoluble matter B1 in 16-hour extraction and from 70.0% by weight to 90.0% by weight of a tetrahydrofuran-soluble matter B2 in 16-hour extraction, and (c) in the binder resin component, from 0.5% by weight to 3.0% by weight of an orthodichloro- benzene-insoluble matter C1 in 6-hour extraction at 185° C. and from 97.0% by weight to 99.5% by weight of an orthodichlorobenzene-soluble matter C2 in 6-hour extraction at 185° C. The proportion of C1 to B1, C1/B1, is from 0.06 to 0.

Abstract: 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.