Canon Kabushiki Kaisha

Yasuo Mitsuhashi

Masaki Uchiyama

Toshiaki Nakahara

Kiichiro Sakashita

Eiichi Imai

Seiichi Takagi

Masashi Kiuchi

Kazunori Murakawa

Hirohide Tanikawa

Kenji Okado

Masanori Takenouchi

Satoshi Yoshida

Satoshi Yasuda

Shuichi Aita

Motoo Urawa

Masatsugu Fujiwara

Yoshinobu Nagai

Naoki Matsushige

Yoshio Takasu

Hiroshi Fukumoto

Takashi Hino

Hisayuki Ochi

Hitoshi Uchide

Seiji Tomari

Hiroyuki Kobayashi

Yasuyuki Tamura

Katsuhiko Tanaka

Tohru Takahashi

Tsutomu Kukimoto

Hatsuo Tajima

Ichiro Ohsaki

Koshi Suematsu

Naoto Kitamori

Kaichi Tsuchiya

Koushi Suematsu

Hiroshi Yamakami

A toner for developing electrostatic latent images with a good combination of fixability, anti-offset characteristic, anti-sticking characteristic and pulverizability contains a composition comprising a colorant or magnetic material and a binder resin. The binder resin has 0.1 to 60 wt. % of a chloroform-insoluble or a THF (tetrahydrofuran)-insoluble component and a THF-soluble component, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that there is a main peak in the molecular weight range of 1,000 to 25,000 and a sub-peak or shoulder in the molecular weight range of 2,000 to 150,000. The binder resin may suitably be obtained through two polymerization steps including a solution polymerization step and a suspension polymerization step.

Binder resin for a toner for developing electrostatic images, and

A toner for developing electrostatic latent images with a good combination of fixability, anti-offset characteristic, anti-sticking characteristic and pulverizability is provided as a composition comprising a colorant or magnetic material and a binder resin. The binder resin has 0.1 to 60 wt. % of a chloroform-insoluble or a THF (tetrahydrofuran)insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that there are a main peak in the molecular weight range of 1,000 to 25,000 and a sub-peak or shoulder in the molecular weight range of 2,000 to 150,000. The binder resin may suitably be obtained through two polymerization steps including a solution polymerization step and a suspension polymerization step.

A developer for developing electrostatic images, containing a magnetic toner having a binder resin and magnetic powder, the developer containing 17-60% by number of magnetic toner particles of 5 microns or smaller, containing 1-23% by number of magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of magnetic toner particles of 16 microns or larger; wherein the magnetic toner has a volume-average particle size of 4-9 microns, and the magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following:

Developer in an image forming device having a binding resin and magnetic

A developer for developing electrostatic images, comprising a non-magnetic toner, the toner containing 17-60% by number of non-magnetic toner particles of 5 microns or smaller, containing 1-30% by number of non-magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of nonmagnetic toner particles of 16 microns or larger; wherein the non-magnetic toner has a volume-average particle size of 4-10 microns, and the non-magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following formula:

Non-magnetic toner

A toner for developing electrostatic latent images with a good combination of fixability, anti-offset characteristic, anti-sticking characteristic and pulverizability is provided as a composition comprising a colorant or magnetic material and a binder resin. The binder resin has 0.1 to 60 wt. % of a chloroform-insoluble or a THF (tetrahydrofuran)-insoluble and a THF-soluble, the THF-soluble providing a molecular weight distribution in the chromatogram of GPC (gel permeation chromatography) thereof such that there are a main peak in the molecular weight range of 1,000 to 25,000 and a sub-peak or shoulder in the molecular weight range of 2,000 to 150,000. The binder resin may suitably be obtained through two polymerization steps including a solution polymerization step and a suspension polymerization step.

Toner for developing electrostatic images, binder therefor and process

A developer for developing electrostatic images, comprising a magnetic toner comprising a binder resin and magnetic powder, the developer containing 17-60% by number of magnetic toner particles of 5 microns or smaller, containing 1-23% by number of magnetic toner particles of 8-12.7 microns, and containing 2.0% by volume or less of magnetic toner particles of 16 microns or larger; wherein the magnetic toner has a volume-average particle size of 4-9 microns, and the magnetic toner particles of 5 microns or smaller have a particle size distribution satisfying the following formula:

Developer and image forming device

A positively chargeable toner for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The toner contains a binder resin, a colorant or magnetic material, and a diorganotin borate. Because of the diorganotin borate contained, the toner has a uniform and stable triboelectric chargeability. The improved properties of the toner are enhanced when it is combined with positively chargeable fine silica powder.

Positively chargeable toner and developer for developing electrostatic

A process for developing a latent image with a developer is provided which comprises

Image forming method

A negative latent image is formed on a photosensitive member comprising an organic photoconductive material. The negative latent image is developed with a positively chargeable developer containing positively chargeable fine silica particles adapted to the organic photosensitive member. The developed image is transferred to a transfer material and the residual toner on the photosensitive member is removed. Thus, copied images without fog can be obtained successively.

Image forming method of negative latent images using silica particles

A developer comprising colored resinous particles and inorganic fine particles having a BET specific surface area of 0.2 to 30 m.sup.2 /g as measured by nitrogen adsorption. The inorganic fine particles have an action of promoting removal of paper powder and other adherents during cleaning of the latent image-bearing member without sticking onto the latent image-bearing member. Accordingly, the developer containing the inorganic fine particles can give good images even after successive copying operation for a long term.

Particulate developer containing inorganic scraper particles and image

A magnetic color toner stable to heat and light which does not fade or discolor for a long period of time is prepared by incorporating .gamma.-Fe.sub.2 O.sub.3 particles as a magnetic component in a toner.

Magnetic color toner containing gamma ferric oxide particles

A method for applying a toner comprising: forming, in a container containing a toner and magnetic particles for application of the toner, a magnetic brush of the magnetic particles; circulating the magnetic particles in the container; and forming a thin layer of the toner electrically charged on the toner carrying member; wherein the magnetic particles have a particle size distribution of 30 wt. % or more in the range of 150 to 200 mesh and 5 wt. % or less of under 250 mesh, and the weight ratio of the toner to the magnetic particles is from 5:95 to 50:50 in the region where the magnetic brush is formed.

Toner application method and developer composition

A method for applying a toner comprising: forming, in a container containing a toner and magnetic particles for application of the toner, a magnetic brush of the magnetic particles; circulating the magnetic particles in the container; forming a thin layer of the toner electrically charged on the toner carrying member, wherein the magnetic particles have been treated with a substance A having a position opposite to that of the toner in the triboelectric series with the material constituting at least the surface of the toner carrying member as the standard substance and with a substance B having a position between the substance A and the toner in the triboelectric series.

Toner application method and treated magnetic particles for use therein

A developer contains a silicone oil which has an amine on side chain thereof, a development process comprises arranging a member holding an electrostatic image on the surface and a member for carrying a toner on the surface and a fixing method comprises contacting a toner image on an image-supporting member with a heated roller, said toner image being formed of a toner which contains a silicone oil having an amine on side chain thereof and has an MI of 0.01-10 g/10 min.

Developer comprising a modified silicone oil and development process for

A developing powder comprises a binder containing 50% by weight or more of a polymer having a gel content of 10% or less and prepared from a vinyl type monomer and a crosslinking agent monomer contained in an amount of 0.01-10% by weight based on the total weight of the monomers, and 0.1-5% by weight of an olefin homopolymer or copolymer having a melt viscosity at 140.degree. C. of 10-10.sup.6 cps.

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Yokohama, Japan

Yasuo Mitsuhashi