Canon Kabushiki Kaisha

Tsuneo Nakanishi

Katsuhisa Yamazaki

Tsutomu Onuma

Nobuyuki Okubo

Kaori Hiratsuka

Hirohide Tanikawa

Takeshi Naka

Takashige Kasuya

Yusuke Hasegawa

Tadashi Dojo

Nene Shibayama

Yuichi Mizoo

Masami Azuma

Satoshi Matsunaga

Yoshihiro Ogawa

Momosuke Takaichi

Kiyoshi Kanai

A toner contains at least a bonding resin and a coloring agent, and has a weight mean particle size from 5 &mgr;m to 12 &mgr;m; not less than 90% by number of particles not less than 3 &mgr;m have a circularity &ldquo;a&rdquo; not less than 0.900; a cut ratio Z and a weight mean size X of the toner are related as: cut ratio Z&lE;5.3&times;X; and a relationship of particles Y having a circularity of not less than 0.950 and a weight mean size X is Y&gE;e &times;X where X is 5 to 12 &mgr;m.

Toner, process for producing toner image forming method and apparatus unit

In a toner production process having at least a kneading step, a pulverization step using a mechanical grinding machine, and a classification step, the grinding means comprises a mechanical grinding machine having at least a rotor which is a rotator attached to the center rotating shaft and a stator which is provided around the rotor, keeping a constant gap between the stator and the rotor surface, the grinding machine being so constructed that a circular space formed by keeping the gap stands airtight, and the surface of at least one of the rotor and the stator is coated by the plating of a chromium alloy containing at least chromium carbide.

Toner production process

A magnetic toner is formed of magnetic toner particles each comprising at least a binder resin and a magnetic iron oxide. The magnetic toner is provided with improved developing performances by realizing an appropriate surface-exposure state of the magnetic iron oxide, which is represented by a wettability characteristic in methanol/water mixture liquids of the magnetic toner such that it shows a transmittance of 80% for light at a wavelength of 780 nm at a methanol concentration in a range of 65-75% and a transmittance of 20% at a methanol concentration in a range of 66-76%.

Magnetic toner and process cartridge

Coarsely crushed toner particles comprising at least a binder resin and a colorant are effectively pulverized by a mechanical pulverizer including a generally cylindrical rotor rotating about an axis and a stator surrounding the rotor with a minute gap from the rotor. Each of the outer wall of the rotor and the inner wall of the stator is provided with a plurality of grooves which extend generally in parallel with the rotation axis of the rotor and are formed of a wave-shaped plurality of projections and intervening recesses. Each recess on at least one of the rotor and the stator is provided with a flat-shaped bottom between a forward corner and a rear corner adjacent a forward slope and a rear slope respectively, with respect to the rotation direction. One corner (rear corner on the rotor or forward corner on the stator) of the two corners receiving an intense flow of the pulverized feed together with conveying air is provided with a dull angle between the adjacent slope and the flat-bottomed surface for effective pulverization.

Toner production system

A dry magnetic toner is formed of magnetic toner particles comprising a binder resin and magnetic iron oxide particles. The magnetic toner is provided with excellent developing performances and transferability by controlling the presence of isolated iron-containing particles and containing a high percentage of spherical particles, the amount of which is controlled relative to the weight-average particle size of the magnetic toner and a content of particles of 3 &mgr;m or below in the magnetic toner.

Dry toner, image forming method and process cartridge

A toner manufacturing method includes grinding and classification to produce a toner containing a binder resin and a colorant with a weight mean particle size of 5 microns to 12 microns and sharp particle density distribution. The toner has a specific circularity, relationship between cut ratio and weight mean size, and relationship between circularity and weight mean size as disclosed in the specification.

A toner has toner particles containing at least a binder resin, a colorant and a sulfur-containing compound selected from the group consisting of a sulfur-containing polymer and a sulfur-containing copolymer. The toner has a weight-average particle diameter of from 5 &mgr;m to 12 &mgr;m, and the toner has, in its particles of 3 &mgr;m or larger in diameter, at least 90% by number of particles with a circularity of 0.900 or higher, and has a specific relationship between the cut rate Z and the toner weight-average particle diameter X and a specific relationship between the number-based cumulative value Y of particles with a circularity of 0.950 or higher and the toner weight-average particle diameter X. Also disclosed are an image-forming method and a process cartridge which make use of the toner.

Toner, image-forming method and process cartridge

A toner is principally constituted by a binder resin, a colorant and a hydrocarbon wax. The hydrocarbon wax has a hydroxyl value (Hv) of 5-150 mgKOH/g and an ester value (Ev) of 1-50 mgKOH/g satisfying Hv>Ev. Further, the toner has a tetrahydrofuran-soluble content providing a gel-permeation chromatogram showing at least one peak in a molecular weight region of 3&times;10 to 5&times;10 and at least one peak or shoulder in a molecular weight region of 1&times;10 to 1&times;10 .

Toner having hydrocarbon wax with specific ester value and hydroxyl value

A toner having a stable chargeability in various environments, a stable fixability over a wide temperature range and a resistance to sticking on an image-bearing member, is formed of a binder resin, a colorant and an azo iron compound as a charge control agent. The azo iron compound is formed from a monoazo compound having at least one alkyl group and two hydroxyl groups capable of bonding with an iron atom. The toner has a tetrahydrofuran-soluble content providing a gel-permeation chromatogram showing at least one peak in a molecular weight region of 3&times;10 to 5&times;10 and at least one peak or shoulder in a molecular weight region of above 5&times;10 and at most 1&times;10 .

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Abiko, Japan

Tsuneo Nakanishi