Canon Kabushiki Kaisha

Takaaki Kotaki

Takayuki Itakura

Takaaki Kaya

Yushi Mikuriya

Wakashi Iida

Nozomu Komatsu

Makoto Kanbayashi

Nobuyoshi Sugahara

Makoto Unno

Kazuhiko Hayami

Tadashi Dojyo

Katsumi Kondo

Atsushi Ishii

Yoshinobu Baba

Yuko Sato

Yojiro Hotta

Yasuhiro Ichikawa

Ryoichi Fujita

Satoshi Matsunaga

Kazuo Terauchi

Tadashi Doujo

Hirohide Tanikawa

Hiroyuki Fujikawa

Yasutaka Akashi

Masaaki Taya

Masaki Uchiyama

Yoshihiko Hyosu

Minoru Shimojo

Yuichi Mizoo

A yellow toner in which, in a spectral-distribution diagram in which the reflectance (%) is plotted as ordinate and the wavelength (nm) as abscissa, the reflectance determined for a toner in a state of powder ranges from 15% to 20% at a wavelength of 500 nm and ranges from 75% to 80% at a wavelength of 600 nm, a cyan toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 30% to 35% at a wavelength of 450 nm and ranges from 35% to 40% at a wavelength of 475 nm, and a magenta toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 5% to 10% at a wavelength of 425 nm and ranges from 65% to 70% at a wavelength of 675 nm. These color toners each contain corresponding pigments in specific combination, and promise color reproduction which can ensure the color tones of process inks.

Color toner, and full-color image-forming method

A yellow toner in which, in a spectral-distribution diagram in which the reflectance (%) is plotted as ordinate and the. wavelength (nm) as abscissa, the reflectance determined for a toner in a state of powder ranges from 15% to 20% at a wavelength of 500 nm and ranges from 75% to 80% at a wavelength of 600 nm, a cyan toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 30% to 35% at a wavelength of 450 nm and ranges from 35% to 40% at a wavelength of 475 nm, and a magenta toner in which, in the like spectral-distribution diagram, the reflectance determined for a toner in a state of powder ranges from 5% to 10% at a wavelength of 425 nm and ranges from 65% to 70% at a wavelength of 675 nm. These color toners each contain corresponding pigments in specific combination, and promise color reproduction which can ensure the color tones of process inks.

Color toner, and full-color image forming method

To provide a yellow toner allowing formation of an image with an excellent transparency for an OHP, an excellent coloring power, and an excellent light resistance. In the yellow toner including at least a yellow pigment containing a monoazo compound represented by the following formula (1), the value of a* is in the range of &#x2212;5 to +14 when b* is +80 with respect to a transmission chromaticity of an image formed on a transparency sheet. (wherein Xto Xeach independently denotes a substituent selected from the group consisting of a hydrogen atom, a C1&#x2013;3 alkyl group, a C1&#x2013;3 alkoxyl group, a nitro group, a halogen group, a sulfonic group, a sulfamoyl group, a sulfamoyl group substituted with an aromatic group, a carboxyl group, and a carboxylate; each may bond with another to form a benzene ring or an imidazolone ring.)

Yellow toner

A toner having toner particles each comprising at least a binder resin, a wax, and a colorant is used in an image forming apparatus which has a fixing means comprising a belt-shaped heating member and a pressurizing member. The binder resin contains a resin formed by a reaction between an epoxy group of a vinyl resin (A) having the epoxy group and a carboxyl group of a resin (B) having at least a polyester unit and the carboxyl group. The toner has a storage elastic modulus at a temperature of 80&#xb0; C. (G' 80) in the range of 1&#xd7;10to 1&#xd7;10Pa and has a storage elastic modulus at a temperature of 160&#xb0; C. (G&#x2032; 160) in the range of 1&#xd7;10to 1&#xd7;10Pa.

Toner and image forming apparatus

The present invention provides a toner: comprising a binder resin comprising a polyester unit, a colorant, a releasing agent, and inorganic fine particles; has a weight average particle diameter of 3.0&#x2013;6.5 &#x3bc;m; has an average circularity of particles in the toner each having a circle-equivalent diameter of 2 &#x3bc;m or more of 0.920&#x2013;0.945; has a BET specific surface area of 2.1&#x2013;3.5 m/g; and has a permeability of light of a wavelength of 600 nm in a liquid having dispersed the toner in a 45 vol % methanol aq. of 30&#x2013;80%. The present invention also provides a two-component developer: comprising the toner and a magnetic carrier comprising magnetic core particles coated by a coating layer; and has a number average particle diameter of 15&#x2013;80 &#x3bc;m. Using the toner and the two-component developer enables a high-quality image to be formed at a high speed even in an oilless fixing system.

Toner and two-component developer

The present invention provides a cyan toner including: one or plural heat-absorption peaks in a temperature range of 30 to 200&#xb0; C. in a heat-absorption curve obtained by using a differential scanning calorimeter; a maximal value of a maximum heat-absorption peak temperature in the range of 65 to 150&#xb0; C.; and a reflectance of 45 to 80% at a wavelength of 500 nm, a reflectance of 5 to 30% at a wavelength of 600 nm, and a brightness L* of 45 to 75, when measured in a powder form by spectroscopic analysis. The present invention thus provides a cyan toner capable of forming an image with reduced graininess and roughness from a low-density region to a high-density region and ensured a sufficient fixing temperature region, and a method for forming an image using the cyan toner.

Cyan toner and method for forming an image

Image-forming method in high-speed mode and in low-speed mode

Magenta toner

In a two-component development system containing a toner and a carrier, an a-Si photosensitive member having a diameter of from 20 mm to 80 mm is used, the photosensitive member is electrostatically charged to have a surface potential of from 300 to 450 V (absolute value), and yellow, magenta, cyan and black toners are used each of which have a weight-average particle diameter of from 4.0 &mgr;m to 10.0 &mgr;m, and, under a condition that the carrier of the two-component developer has a 50% average particle diameter of from 10 &mgr;m to 80 &mgr;m and as image density (D0.5) measured usually after the toner is fixed once when the quantity of unfixed toner on a transfer medium, M/S, is 0.5 mg/cm , have a coloring power of from 1.0 to 1.9, and in which the difference between a maximum value and a minimum value of D0.5 of yellow, magenta, cyan and black colors is form 0 to 0.5. This makes it possible to obtain high-quality images in a high image density and a superior color reproduction.

Image-forming method and image-forming apparatus

The toner for developing an electrostatic image has toner particles containing at least binder resin and colorant. The resin components of a range of 2,000 to 100,000 in molecular weight, prepared by preparatory liquid chromatograph from the binder resin, exhibit an M/S ratio of 200 or greater and are 50% to 90% in abundance. The M and S stand for a weight average molecular weight (M) measured by means of light scattering method and an inertia radius (S) measured by means of light scattering method, respectively.

Toner for developing an electrostatic image

A toner for developing an electrostatic image has a binder resin, a colorant and a charge control agent. The binder resin has a polyester resin having an acid value of from 15 to 40 and a hydroxyl value of 45 or less. The toner has, in its molecular weight distribution as measured by gel permeation chromatography, tetrahydrofuran-soluble matter having a weight average molecular weight Mw of 100,000 or more, having a ratio of weight average molecular weight Mw to number average molecular weight Mn, Mw/Mn, of not less than 35, containing from 70% to 94% of a low-molecular weight region component having a molecular weight of less than 150,000, containing from 1% to 10% of a medium-molecular weight region component having a molecular weight of from 150,000 to 500,000, and containing from 5% to 25% of a high-molecular weight region component having a molecular weight of more than 500,000. The high-molecular weight region component is more than the medium-molecular weight region component.

Toner for developing electrostatic images

A magnetic toner composed of a binder resin and magnetic fine particles, wherein the magnetic fine particles are coated with an iron-zinc oxide on their surfaces and the magnetic fine particles have a saturation magnetization (.sigma.s) of 50 Am.sup.2 /kg or above under a magnetic field of 79.58 kA/m (1K oersted) where the product of residual magnetization (.sigma.r, Am.sup.2 /kg) and coercive force (Hc, kA/m), .sigma.r.times.Hc, is in the range between 60 and 250 (kA.sup.2 m/kg).

Magnetic toner and image forming method

A toner for developing electrostatic images comprises, (i) a binder resin, (ii) a colorant, and (iii) a compound made by a reaction of a monohydroxylic compound having a long-chain alkyl group having an alkylene group with 40 or more carbon atoms and a hydroxyl group with a carboxylic acid having a molecular weight of 1,000 or less, or a compound made by a reaction of a monocarboxylic compound having a long-chain alkyl group having an alkylene group with 40 or more carbon atoms and a carboxyl group with an alcohol having a molecular weight of 1,000 or less.

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Shizuoka, Japan

Takaaki Kotaki