Canon Kabushiki Kaisha

Tsutomu Onuma

Hirohide Tanikawa

Nobuyuki Okubo

Masami Fujimoto

Koji Nishikawa

Kaori Hiratsuka

Shuhei Moribe

Tsuneo Nakanishi

Minoru Shimojo

Takashige Kasuya

Hiroyuki Fujikawa

Katsuhisa Yamazaki

Shinichiro Abe

Toshiaki Nakahara

Hiroaki Kawakami

Keita Nozawa

Kazuyoshi Hagiwara

Masatsugu Fujiwara

Rika Shinba

Yoshihiro Ogawa

Hideto Iida

Masashi Jinbo

Yusuke Hasegawa

Takakuni Kobori

Manabu Ohno

Tomohisa Sano

Satoshi Matsunaga

Shinji Doi

Junko Nishiyama

Masaichiro Katada

Miho Okazaki

Masao Takano

A process for producing a toner by subjecting a polymer and a resin component containing a cross-linkable polymer capable of cross-linkingly reacting with the polymer, to cross-linking reaction in the presence of a first wax to form a wax-containing cross-linked polymer composition; mixing the wax-containing cross-linked polymer composition with at least a colorant and a second wax, followed by melt-kneading to form a toner composition; and pulverizing the toner composition to produce toner particles. Also disclosed is a toner produced by this process. The toner thus obtained is a toner whose fixing performance and anti-offset properties are well balanced and also which makes it possible to afford images having less fog and high quality, over a long period of time in environments of from low temperature and low humidity to high temperature and high humidity, and is highly durable without causing any contamination of members with which the toner comes into contact.

Process for producing toner, and toner

An image forming method and related process cartridge, the method having the steps of controlling the layer thickness of a toner on a toner bearing member by means of a toner regulating blade, and developing with the toner an electrostatic latent image formed on an electrostatic latent image bearing member, the toner regulating blade has, at its part to be kept in touch with the toner bearing member, a specific ten-point average roughness Rz and a specific ratio (area of contact portion/area of non-contact portion) at a specific face pressure, and the toner has a specific average circularity and has a specific aerated bulk density. This image forming method and process cartridge promise superior developing performance in any environment, can keep sleeve negative ghost from occurring and can keep toner melt adhesion to toner regulating blade and toner melt adhesion to toner bearing member from occurring.

Image forming method and process cartridge using specific toner regulating blade and toner

A toner is disclosed including toner particles containing a binder resin and a colorant. The binder resin contains a vinyl resin. In the high-temperature GPC-RALLS-viscometer analysis of the o-dichlorobenzene-soluble matter of the toner, a weight-average molecular weigh of absolute molecular weights measured with a viscosity detector is in a specific range. In the o-dichlorobenzene-soluble matter, a component with the absolute molecular weight of 10,000 or less and a component with the absolute molecular weight of 1,000,000 or more are present in specific proportions, respectively. The intrinsic viscosity of the toner is in a specific range.

Toner

A toner is composed of toner particles including toner base particles containing at least a binder resin and a colorant, and inorganic fine particles. The toner base particles having a specific circle-equivalent diameter as measured with a flow type particle image analyzer have a specific average circularity. The toner base particles have a specific surface roughness as measured with a scanning probe microscope. The binder resin contains at least a vinyl resin having as partial structure a linkage formed by the reaction of a carboxyl group with an epoxy group.

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 &#x3bc;m or more to 400 &#x3bc;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.

A process cartridge which is detachably mountable to a main body of an image-forming apparatus has a photosensitive member, a magnetic toner-holding section provided with a magnetic toner-carrying member which transports the toner to a developing zone, and a residual magnetic toner detector capable of detecting residual toner by a change in electrostatic capacity which is caused between electrodes provided inside the magnetic toner-holding section. The magnetic toner contains at least a binder resin and a colorant, having a weight-average particle diameter of from 6.5 &mgr;m to 15.0 &mgr;m, and having a Carr's floodability index of more than 80.

Process cartridge

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

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 for developing an electrostatic image is formed of toner particles; wherein each toner particle includes (i) 100 wt. parts of a binder resin having a glass transition point (Tg) of 50-70&deg; C., (ii) 0.2-20 wt. parts of solid wax, and (iii) colorant particles or magnetic powder; (iv) lubricant particles carrying a liquid lubricant, so that the toner particle retains at its surface the liquid lubricant gradually released from the particles (iv). The toner may be further blended with an organically treated inorganic fine powder to provide a developer. The toner or developer retains good lubricity and releasability so that it is suitable to be used in an image forming method including means contacting a latent image-bearing means, such as a contact charging means, a contact transfer means or a contact cleaning means.

Method using toner and developer for developing electrostatic image

Toner for developing electrostatic images and heat fixing method

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 .

Toner containing azo iron compound

A toner for developing an electrostatic image is formed of toner particles; wherein each toner particle includes (i) 100 wt. parts of a binder resin having a glass transition point (Tg) of 50-70&deg; C., (ii) 0.2-20 wt. parts of solid wax, and (iii) colorant particles or magnetic powder, (iv) lubricant particles carrying a liquid lubricant, so that the toner particle retains at its surface the liquid lubricant gradually released from the particles (iv). The toner may be further blended with an organically treated inorganic fine powder to provide a developer. The toner or developer retains good lubricity and releasability so that it is suitable to be used in an image forming method including means contacting a latent image-bearing means, such as a contact charging means, a contact transfer means or a contact cleaning means.

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Kanagawa, Japan

Tsutomu Onuma