Canon Kabushiki Kaisha

Minoru Shimojo

Atsushi Tanaka

Akira Shimada

Tsunenori Ashibe

Masami Fujimoto

Toshiaki Nakahara

Kazuyoshi Hagiwara

Hiroyuki Kobayashi

Akihiko Nakazawa

Takashi Kusaba

Hidekazu Matsuda

Tsutomu Onuma

Hiroyuki Osada

Hirohide Tanikawa

Keita Nozawa

Rika Shinba

Satoshi Matsunaga

Kiyoshi Mizoe

Tsuyoshi Takiguchi

Manabu Ohno

Makoto Kanbayashi

Ryoichi Fujita

Takaaki Kohtaki

Yoshihiko Hyosu

Takaaki Kotaki

An endless belt for electrophotography is disclosed which is obtainable continuously by melt extrusion from a circular die. The endless belt has a layer containing a thermoplastic resin having a diphenyl sulfone structure represented by the following Formula (1)Also disclosed are a process for producing the endless belt and an image forming apparatus having the endless belt.

Endless belt electrophotography, process for producing the endless belt, and image forming apparatus having the endless belt

In a negatively chargeable toner having i) negatively chargeable toner particles containing at least a binder resin, a colorant and a vinyl copolymer and ii) an inorganic fine powder, the negatively chargeable toner has a weight-average particle diameter of from 4 &#x3bc;m to 12 &#x3bc;m and contains, in particle size distribution of the toner, less than 50% by volume of particles of 10.1 &#x3bc;m or more in particle diameter, and the vinyl copolymer is a vinyl copolymer obtained by copolymerizing a monomer composition which contains at least i) a vinyl monomer such as an N-substituted acryl- or methacrylamide or a ring-structure acryl- or methacrylamide and ii) a vinyl monomer having as a functional group a carboxyl group or a carboxyl group made into salt structure. An image-forming method and a process cartridge make use of such a negatively chargeable toner.

Negatively chargeable toner, image-forming method and process cartridge

A process produces a belt-shaped member to be used in an image-forming apparatus is disclosed in which a toner image held on a latent-image-bearing member is electrostatically transferred under application of a voltage via the belt-shaped transfer member. The process includes the steps of melt-extruding a material containing a thermoplastic resin, from a circular die into a cylindrical film; forming the resultant cylindrical film by stretching in such a way that the cylindrical film comes to have a thickness smaller than the die gap of the circular die; and cutting the cylindrical film thus formed, into a seamless belt having a thickness of from 40 &mgr;m to 300 &mgr;m and a modulus in tension of 600 MPa or higher. The stretched cylindrical film is formed to have a thickness not larger than &frac13; of the die gap of the circular die. A belt-shaped transfer member may be produced by the above-described process. The so-produced belt-shaped transfer member is usable as a transfer belt in an image-forming apparatus in which a toner image held on a latent-image-bearing member is electrostatically transferred under application of a voltage via the belt-shaped transfer member.

Process for producing belt-shaped member from a die-extruded film having a film thickness, die gap relationship

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 process for producing an endless belt includes melt-extruding an extrusion material into a cylinder by means of an extruder, where the extrusion material has a tensile break strength of 400 kgf/cm,or above and a breaking extension of from 3.0% to 250%, and where the extrusion material is extruded in an extrusion ratio of from 1.05 to 2.80 while a gas is blown into the inside of the melt-extruded cylindrical product.

Process of making an endless belt

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

An intermediate transfer member is formed by at least a base layer and a surface layer. The base layer is formed by epichlorohydrin rubber and acrylonitrile-butadiene rubber mixed in a certain weight ratio (preferably 1:9 to 9:1). The surface layer is formed by urethane resin or elastomer and a fluorine-containing compound powder. The fluorine-containing compound powder may preferably be contained in an amount of 20-80 wt. % based on the surface layer. The intermediate transfer member is suitable for full-color image formation by electrophotography and is effective in improving a transfer performance and providing clear images without causing transfer failure even in repetitive use for a long period.

Intermediate transfer member and electrophotographic apparatus including

An intermediate transfer member for receiving a toner image formed on a first image-bearing member and transferring the toner image onto a second image-bearing member has a surface coated with at least one of a nitrate ion adsorbent and a compound having a layer structure, whereby a scattering of toner particles during a successive image formation is effectively suppressed for a long period.

Intermediate transfer member and image forming apparatus

An image forming apparatus has a first image bearing member and an intermediate transfer member onto which a toner image formed on the first image bearing member is primarily transferred and through which the toner image thus transferred is secondarily transferred onto a second image bearing member. The intermediate transfer member has a surface layer on a base layer and the surface layer contains a polyurethane resin obtained by the reaction of an olefinpolyol with an isocyanate.

Image forming apparatus and intermediate transfer member

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

An image forming apparatus has a first image bearing member and an intermediate transfer belt onto which a toner image formed on the first image bearing member is primarily transferred is secondarily tranferred onto a second image bearing member. The intermediate tranfer belt has, in its non-image forming region, a tape having a volume resistivity of 10.sup.10 .OMEGA..multidot.cm or above, a bond strength of 0.5 kg or above and a breaking extension of 5% or more.

Image forming apparatus and intermediate transfer belt

The present invention concerns an image forming apparatus for forming a toner image on a transfer medium by use of an intermediate transfer belt, and also the intermediate transfer belt itself. The intermediate transfer belt has an elastic layer JIS-A hardness of which is 85.degree. or less and at least one covering layer formed on the elastic layer. A relative permittivity .epsilon. and thickness t (.mu.m) of the at least one covering layer satisfy relations of .epsilon..ltoreq.6 and t.gtoreq..epsilon., and the intermediate transfer belt includes a fiber. The effects of this .epsilon. value and the fiber inside enabled to suppress scattering of toner well.

Intermediate transfer belt and image forming apparatus adopting the belt

A toner for developing electrostatic images is prepared from a binder resin, a colorant or magnetic material, and a wax component. The toner is provided with improved low-temperature fixability anti-electrostatic offset characteristic, anti-blocking characteristic and anti-offset characteristic by controlling the thermal characteristic of the wax component so as to provide a DSC (differential scanning colorimeter) curve on temperature increase, showing a minimum onset temperature of heat absorption of at least 50.degree. C. and at least two heat absorption peaks including a largest and a second largest peaks, different from each other in peak temperature by at least 15.degree. C., wherein low-temperature heat absorption peak P.sub.1 of the two peaks shows a half-value width of at most 20.degree. C. and a higher-temperature heat absorption peak P.sub.2 shows a half-value width of at most 20.degree. C., and wherein the peak P.sub.1 shows a higher half-width temperature and the peak P.sub.2 shows a lower half-width temperature different form the higher half-width temperature of the peak P.sub.1 by at least 5.degree. C.

Toner with wax component for developing electrostatic image

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;

Growing community of inventors

Kawasaki, Japan

Minoru Shimojo