Canon Kabushiki Kaisha

Hiroaki Kawakami

Shinji Doi

Masatsugu Fujiwara

Hirohide Tanikawa

Yuji Moriki

Takashige Kasuya

Satoshi Matsunaga

Yusuke Karami

Michihisa Magome

Tatsuhiko Chiba

Shinya Yachi

Masayuki Hama

Satoshi Handa

Tatsuya Nakamura

Koh Ishigami

Kentaro Kamae

Kazunori Kato

Yasuhide Goseki

Tsutomu Onuma

Noriyoshi Umeda

Yoshinobu Baba

Masaya Kawada

Katsuyuki Nonaka

Masaharu Miura

Masuo Yamazaki

Koji Inaba

Kiyokazu Suzuki

Kiyoko Tsuchiya

Masashi Jinbo

Kiyoko Maeda

Takeshi Ikeda

Tetsuya Kobayashi

Satoshi Yoshida

Kazuo Yoshinaga

Tatsuya Kobayashi

Hiroshi Sasame

Yoshihiro Nakagawa

Kenji Okado

Akihiko Uchiyama

Yojiro Hotta

Yoshiro Saito

Atsuyoshi Abe

Naoki Enomoto

Ryoichi Fujita

Koichi Tomiyama

Satoshi Yasuda

Haruo Fujii

Yasuhiro Hashimoto

Hitoshi Kanda

Keiji Komoto

Keita Nozawa

Yoshihiko Hyosu

Takeshi Naka

Hiromi Mori

Fumihiro Arahira

Ryuichiro Matsuo

Kohji Inaba

Satoshi Mita

Kuniko Kobayashi

Youichirou Maebashi

Masashi Jimbo

Provided is a toner, including toner particles each containing a binder resin containing a polyester &#x3b1; as a main component, a colorant, a wax, and a crystalline polyester, in which: the polyester &#x3b1; has a polyhydric alcohol unit and a polyvalent carboxylic acid unit; and the polyester &#x3b1; has, as the polyhydric alcohol unit, a polyhydric alcohol unit N derived from an alkylene oxide adduct of a novolac type phenol resin.

Toner and two-component developer

A method of producing a magnetic carrier, having a coating process step in which a surface of a magnetic carrier core is coated with particles of a resin composition by a mechanical impact force. The coating process step has a first coating process step of mixing, dispersing, and fixing the particles on the surface of the core, and a second coating process step, which is performed after the first coating process step, of carrying out a film-forming coating process on the particles. In the first and second coating process steps, the peripheral velocity of the outermost end of stirring members, the coating process time, the product temperature at the end of the coating process, and the glass-transition temperature of the resin component satisfy specific relationships.

Method of producing magnetic carrier and magnetic carrier that uses this production method

Provided is a magnetic carrier excellent in leakage, uniformity of a solid image having satisfactory charging stability and developing performance at low electric field. The magnetic carrier is a magnetic carrier comprising: a magnetic substance-dispersed resin carrier core, which contains a magnetic substance and a binding resin, and a coating resin on a surface thereof, wherein: the carrier core has resistivity at 1000 V/cm of 5.0&#xd7;10-8.0&#xd7;10&#x3a9;&#xb7;cm, the magnetic substance has a number average particle diameter of 0.20-0.35 &#x3bc;m; and comprises magnetic-substance particles having vertexes and a particle diameter of 0.53 &#x3bc;m or more in an amount of 10.0-32.0 vol % based on a total amount of the magnetic substance; and wherein: the carrier core has FeOcontent of 98.00% by mass or more; and ZnO content of 0.06-0.50% by mass.

Magnetic carrier and two-component developer

An image forming apparatus provided with a photosensitive member, a charging device for charging the photosensitive member, a developing device for developing an electrostatic image formed on the photosensitive member by a developer, a cleaning blade for removing the developer residual on the photosensitive member, a rubbing member provided upstream of the cleaning blade in the direction of rotation of the photosensitive member for rubbing the photosensitive member to assist the cleaning blade in cleaning, and a controller for controlling the surface temperature of the photosensitive member, wherein the photosensitive member has the HU (universal hardness value) of 150 N/mmor greater and 220 N/mmor less, and the elastic deformation rate of 43% or greater and 65% or less.

Image forming apparatus

The invention is to provide an image forming method of a long service life, a high image quality and a low running cost, capable of maintaining a stable cleaning performance over a prolonged period without causing an image deletion phenomenon, even with a image bearing member such as a photosensitive member, of a high durability (high strength and high abrasion resistance). The invention provides an image forming method characterized in that the image bearing member has a universal surface hardness HU of 150 to 220 N/mmand an elastic deformation ratio We of 40 to 65%, and, for a crossing angle &#x3b8; (&#xb0;) between a rotary axis of the contact charging roller and a rotary axis of the image bearing member, for a ratio A (weight %) of the transfer residual toner and the abrasive particles and for a contact pressure B (g/cm) of the cleaning blade, HU, We, A, B and &#x3b8; satisfy the following relations (I), (II) and (III):(1/6000)&#xd7;&#x2003;&#x2003;(I)&#x2003;&#x2003;(II)10&#x2266;B&#x2266;50. &#x2003;&#x2003;(III)

Image forming method capable of maintaining sustained stable cleaning performance without causing an image smearing phenomenon even with a high strength and high abrasion image bearing member

In a toner having toner particles which have toner base particles having at least a colorant and a binder resin, and an inorganic fine powder; the inorganic fine powder has a primary-particle average particle diameter of from 30 nm to 300 nm, and has particles having at least one of a cubic particle shape, a cube-like particle shape, a rectangular particle shape and a rectangle-like particle shape and having perovskite type crystals; and the inorganic fine powder has particles and agglomerates both having particle diameters of 600 nm or more, in a content of 0% to 1% by number.

Toner

In a process cartridge having a latent-image-bearing member and a developing device having a developer-holding part and a developing member, at a vertical section which bisects in the process cartridge the surface of the latent-image-bearing member with which surface the developing member is brought into pressure contact, a developer agitation and transport member has at least two rotary agitation and transport members having rotating shafts falling at right angles with the vertical section. Where, at the vertical section, the area of the developer-holding part is represented by S1 and the area of the part corresponding to the movable region of the rotary agitation and transport member is represented by S2, the ratio of S2 to S1, S2/S1, is from 0.8 to 0.99; and the ratio of a long side Sa to a short side Sb, Sa/Sb, of a circumparallelogram having a minimum area in respect to the area S1 in the vertical section is from 1.5 to 3.0. The non-magnetic one-component developer contains at least a binder resin and a colorant and has a fluidity index of from 50 to 90 and a floodability index of from 45 to 96.

Integral-type process cartridge and developing-assembly unit including non-magnetic one-component toner

A toner having a good chargeability stable against an environmental change is formed of toner particles each comprising at least a binder resin, a colorant, a release agent and a sulfur-containing polymer, and an external additive. The toner particles contain 100 to 30,000 ppm by weight thereof of at least one stabilizer element selected from the group consisting of magnesium, calcium, barium, zinc, aluminum and phosphorus. The toner particles may preferably be produced by suspension polymerization of a monomer composition containing the sulfur-containing polymer in an aqueous medium containing a dispersion stabilizer having the stabilizer element.

Toner, toner production process and image forming method

Image forming method

Toner for developing electrostatic images and heat fixing method

A process for producing a polymerization toner, which comprises preparing a polymerizable-monomer composition which contains at least a polymerizable monomer and a colorant and does not contain any polymerization initiator, i) introducing the polymerizable-monomer composition into an aqueous medium to effect granulation, adding a polymerization initiator to the aqueous medium in the course of the granulation or after the granulation has been completed, or ii) adding a polymerization initiator in an aqueous medium, introducing the polymerizable-monomer composition into the aqueous medium to effect granulation, and then polymerizing the polymerizable-monomer composition having been granulated, to produce toner particles. In the process, the polymerization initiator is added in a specific time and a specific manner.

Process for producing polymerization toner

A toner has toner particles and an external additive. The toner particles have a weight-average particle diameter of from 4 &mgr;m to 9 &mgr;m. The external additive has (i) first, small-particle-diameter hydrophobic fine silica particles (A) having a BET specific surface area of from 100 m,/g to 350 m,/g, having been treated with a silane, (ii) second, large-particle-diameter hydrophobic fine silica particles (B) having a BET specific surface area of from 15 m,/g to 80 m,/g, having been treated with a silicone oil, and (iii) fine alumina particles (C) having a BET specific surface area of from 50 m,/g to 150 m,/g.

Toner, image forming method, and apparatus unit

A yellow toner suitable for electrophotography is formed by dispersing a yellow colorant mixture in a binder resin. The yellow colorant mixture is formed of at least a pigment of formula (1) or (2) below, and a dye of formula (3) below:

Yellow toner, process for producing the tower and image forming method using the toner

An electrophotographic toner is formed of toner particles each comprising at least a binder resin, a colorant and a release agent, and a low-crystalline aromatic metal compound present at surfaces of the toner particles. The toner has an average circularity of at least 0.955, and the low-crystalline aromatic metal compound has an X-ray diffraction characteristic free from peaks exhibiting a measurement intensity of at least 10000 cps and a half-value half-width of at most 0.3 deg. in a range of measurement angles 2&thgr; of 6 to 40 deg. Because of the low crystallinity, the aromatic metal compound is uniformly applied onto the toner particle surfaces to stabilize the chargeability and transferability of the toner.

Toner and image forming method

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Yokohama, Japan

Hiroaki Kawakami