Canon Kabushiki Kaisha

Kazuyoshi Hagiwara

Masami Fujimoto

Toshiaki Nakahara

Hirohide Tanikawa

Katsuhiko Tanaka

Minoru Shimojo

Keita Nozawa

Tsutomu Onuma

Kiyoshi Mizoe

Rika Shinba

Yushi Mikuriya

Masayoshi Shimamura

Kuniko Kobayashi

Tsutomu Kukimoto

Tsuyoshi Takiguchi

Yasutaka Akashi

Masaaki Taya

Masaki Uchiyama

Satoshi Matsunaga

Makoto Unno

Yoshinobu Joh

Rika Doi

Minoru Shimojyo

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

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.

Toner and developer for developing electrostatic image, process for production thereof and image forming method

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.degree. C., (ii) 0.2-20 wt. parts of solid wax, and (iii) colorant particles or magnetic powder carrying a liquid lubricant, so that the toner particle retains at its surface the liquid lubricant gradually released from the particles (iii). 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.

Toner and developer for developing electrostatic image, process for

A toner for developing an electrostatic image has toner particles containing at least a binder resin and a colorant, and an inorganic fine powder. The inorganic fine powder has been treated with a silicone oil having, in its molecular weight distribution as measured by gel permeation chromatography, at least one peak value in the region of molecular weight of from 500 to 15,000 and having at least one peak value or shoulder in the region of molecular weight of from 3,000 to 100,000 at a value greater than the former peak value.

Toner for developing electrostatic image, image forming method,

A magnetic toner which is excellent in the low temperature fixability and the anti-offset properties is disclosed. The binder resin of the toner comprises a non-crosslinked styrene polymer, a non-crosslinked styrene copolymer or a mixture of these, and a polyolefin, wherein;

Magnetic toner and process for producing magnetic toner

A developer for developing electrostatic images has a toner and an aggregate of fine particles. The aggregate holds a silicone compound selected from the group consisting of a silicone oil and a silicone varnish, in an amount of from 20% by weight to 90% by weight.

Developer for developing electrostatic images and image forming method

A toner for developing electrostatic images has a binder resin having as a constituent an acid component with an acid value of from 0.5 mg.KOH/g to 100 mg.KOH/g, a colorant, and at least one of compounds represented by Formulas (I), (II) and (III).

Toner for developing electrostatic images, image forming apparatus,

A toner for developing an electrostatic image is composed by a binder resin, and a magnetic material and/or a colorant. The binder resin (a) comprises a styrene resin polymerized in the presence of a poly-functional polymerization initiator, (b) provides a molecular weight distribution on a GPC chromatogram showing a maximum (P1) in a molecular weight range of 3.5.times.10.sup.3 -5.times.10.sup.4 and a maximum (P2) or shoulder in a molecular weight range of at least 1.times.10.sup.5, and (c) contains 15 wt. % or less of a resin component in a molecular weight range of at most 3.times.10.sup.3. Further the toner contains at most 100 ppm of styrene and benzaldehyde.

Toner for developing electrostatic image and image forming method

The present invention relates to an electrophotographic image forming method characterized in using a photosensitive member having an organic photoconductive layer and fluorine-containing resin particles in the surface, a contact charging means being in contact with the photosensitive member to electrostatically charge it, a contact transfer means being in contact with the photosensitive member to transfer the developed image to the transfer medium;

Image forming method, image forming apparatus and apparatus unit

The present invention provides a developer which is comprised of the magnetic toner having the specific binder resin component and low-molecular weight wax and the additives of the fine silica powder, metal oxide powder and fluorine-containing fine resin powder which are used in combination in given amounts. Hence, it is possible to prevent the melt-adhesion of toner to the surfaces of the contact charging member and contact transfer member, to cause no faulty images and to obtain images with the enjoyment of superior low-temperature fixing performance and anti-offset properties, even when copies are taken on a large number of sheets using the image forming method having contact charging and contact transfer systems.

Developer for developing electrostatic image, image forming method,

A guanidine type compound has the following formula: ##STR1## wherein R.sup.1 to R.sup.8 are each a hydrogen atom, an alkyl group, an amino group, an alkoxy group, a substituted or unsubstituted aryl group, and R.sup.1 to R.sup.8 may be the same as or different from each other and together may form a ring with the adjacent substituents; X is a halogen atom, a hydroxyl group or an alkoxy group; and m and n are each an integer having a value of 1 to 8. The guanidine compound is employed in a toner for electrostatic development and the toner can be used in an electrophotographic apparatus including a facsimile apparatus for receiving image information from an electrophotographic copier.

Imaging method comprising a developer having a novel guanidine type

A magnetic toner is constituted by at least a binder resin and a magnetic iron oxide. The magnetic iron oxide is characterized by having an Fe(II) content of 18.5-24.1 wt. %, and shows a BET specific surface area of S (m.sup.2 /g) and an X-ray diffraction pattern giving a half-value width W (deg.) of a diffraction peak corresponding to 311 plane of the magnetic iron oxide in spinel structure, the values S and W satisfying: 4.5.times.10.sup.-3 S+0.130.ltoreq.W.ltoreq.4.5.times.10.sup.-3 S+0.160, and 4.5.ltoreq.S.ltoreq.11.0. Alternatively, the magnetic iron oxide is characterized by having a number-average particle size D satisfying a relationship with W of: -0.08D+0.180.ltoreq.W.ltoreq.-0.08D+0.212, and 0.10.ltoreq.D.ltoreq.0.45. The relationship between W and S or D indicates a good crystallinity of the magnetic iron oxide which provides the magnetic toner with a stable performance for a long period of time. The magnetic iron oxide can be obtained through a heating treatment at a temperature of 130.degree.-360.degree. C. within a gaseous mixture of hydrogen and nitrogen containing 50 vol. % or less of hydrogen or at a temperature of 150.degree. -450.degree. C. in an inert gas.

Magnetic toner

A developer for developing electrostatic images is constituted by toner containing a binder resin and a charge controller. The charge controller comprises an arylurea compound which is an arylurea having at least one electron-attracting group or electron-donating group, or a polyarylurea including such an arylurea as a recurring unit. The arylurea compound is substantially colorless and can have stable but different levels of triboelectric chargeability depending on the substituents.

Developer for developing electrostatic image, image forming apparatus,

A toner for developing an electrostatic image is provided as a pulverized mixture including a binder resin and a colorant. The binder resin is characterized by a molecular weight distribution on a GPC chromatogram of its tetrahydrofuran (THF)-soluble resin content including below 15% of a resin component in a molecular weight region of at most 5000 and at least 5 wt. % of a resin component in a molecular weight region of at least 5.times.10.sup.6 and showing a main peak in a molecular weight region of 5000 to 5.times.10.sup.6. The THF-soluble resin component in the molecular weight region of at least 5.times.10.sup.6 is extremely enriched during a melt-kneading step during the toner production, so as to effectively prevent toner flowout from a member for cleaning a fixing roller.

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Tokyo, Japan

Kazuyoshi Hagiwara