Canon Kabushiki Kaisha

Makoto Kanbayashi

Wakashi Iida

Tatsuya Nakamura

Tatsuhiko Chiba

Takashige Kasuya

Takayuki Nagatsuka

Ryoichi Fujita

Kenji Okado

Tsuyoshi Takiguchi

Tetsuya Ida

Masaaki Taya

Takaaki Kotaki

Hirohide Tanikawa

Takaaki Kaya

Yasuhiro Ichikawa

Koji Inaba

Kazuyuki Miyano

Kohji Inaba

Katsumi Kondo

Takayuki Itakura

Yushi Mikuriya

Takeshi Menjo

Toshiyuki Ugai

Kazuo Suzuki

Yuichi Ikeda

Nobuatsu Sasanuma

Tomohisa Itagaki

Yoshinobu Baba

Nozomu Komatsu

Nobuhiko Zaima

Yojiro Hotta

Nobuyoshi Sugahara

Akihiko Nakazawa

Kazunori Kato

Shinya Yachi

Kenichi Nakagawa

Makoto Unno

Kazumi Yoshizaki

Yoshihiko Hyosu

Minoru Shimojo

Ichiro Ohsaki

Takeshi Ohtake

Image data supplied to an image forming apparatus are converted into image data linearly correlated with the image density, and the image ratio is calculated by dividing the number of pixels in which the toner is deposited during image formation based on the thus-converted image, with a value obtained by multiplying the total pixel number corresponding to the size of the print medium with the number of gradation levels per pixel. Then the toner amount consumed in the image formation based on the entered image data is determined by multiplying the image ratio, the size of the print medium to be used and the toner amount consumed per unit area in a solid image formation.

Image ratio measuring method for image forming apparatus

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

A two-component developer is formed as a mixture of a negatively chargeable toner and a resin-coated carrier. The toner comprises at least a binder resin, a colorant and an organic metal compound. The organic metal compound is an organic zirconium compound having a coordination or/and a bonding of zirconium and an aromatic compound as a ligand or/and an acid source selected from the group consisting of aromatic diols, aromatic hydroxycarboxylic acids, aromatic monocarboxylic acids, and aromatic polycarboxylic acids. The toner further includes an external additive comprising hydrophobized inorganic fine powder having an average primary particle size of 0.001-0.2 &mgr;m. The resin-coated carrier has a 50%-particle size of 20-70 &mgr;m.

Two-component developer and image forming method

Carrier for use in electrophotography, two-component type developer and image forming method

A toner having a negative triboelectric chargeability and suitable for developing positively or negatively charged images is composed of at least a binder resin, a colorant and an organic metal compound. The organic metal compound is an organic zirconium compound comprising a coordination or/and a bonding of zirconium and an aromatic compound as a ligand or/and an acid source selected from the group consisting of aromatic diols, aromatic hydroxycarboxylic acids, aromatic monocarboxylic acids, and aromatic polycarboxylic acids.

Toner having negative triboelectric chargeability and developing method

A yellow toner for developing electrostatic images is formed of yellow toner particles containing a binder resin and a yellow colorant. The yellow toner has a storage modulus G'.sub.180 at 180.degree. C. and a minimum storage modulus G'.sub.min(120-170) in a temperature range of 120-170.degree. C. giving a ratio [G'.sub.180 /G'.sub.min(120-170) ] of 2.0-8.0. The binder resin comprises a polyester resin having a glass transition temperature of 50-65.degree. C. and an acid value of 2.0-25.0 mgKOH/g. The yellow toner is a compound represented by Formula (1) below: Formula (1): ##STR1## The primary particles of the yellow colorant exhibit a length/breadth ratio of at most 1.5. The yellow colorant is dispersed in the toner particles as independent particles (including primary particles and secondary particles) providing a number-average particle size of 0.1-0.7 .mu.m. The yellow toner is provided with improved fixability and anti-offset property as well as good color toner performances.

Yellow toner for developing electrostatic images

A color toner has (i) color toner particles containing at least a binder resin and a colorant and (ii) an external additive. The color toner has a weight-average particle diameter of 5 to 8 .mu.m and a number-average particle diameter of 4.5 to 7.5 .mu.m, and contains 5 to 40% by number of particles having a particle diameter of 4 .mu.m or less in the number distribution of the color toner and 7% by volume or less of particles having a particle diameter of 10.08 .mu.m or more in the volume distribution of the color toner. The inorganic powder selected from the group consisting of a strontium titanate powder, a cerium oxide powder and a calcium titanate powder, and a hydrophobic fine alumina powder are externally added to the color toner particles as the external additives, the inorganic powder has a longitudinal average particle diameter of 0.2 to 2 .mu.m, and the hydrophobic fine alumina powder has a longitudinal average particle diameter of 0.005 to 0.1 .mu.m. The binder resin is a polyester resin crosslinked by a crosslinking agent. The color toner particles contain 0 to 20 mg/lg of a chloroform insoluble matter. The color toner has a storage modulus (G'.sub.130) of 2.times.10.sup.3 to 2.times.10.sup.4 [dyn/cm.sup.2 ] at a temperature of 130.degree. C. and a storage modulus (G'.sub.170) of 5.times.10.sup.3 to 5.times.10.sup.4 [dyn/cm.sup.2 ] at a temperature of 170.degree. C., and a value of G'.sub.170 /G'.sub.130 is in the range of 0.25 to 10.

Color toner and image forming method

An electrophotographic two-component type developer includes a toner and a magnetic carrier showing stable charge-imparting performances for a long period of continuous image formation and wherein various environmental conditions. The magnetic carrier comprises: magnetic carrier core particles and a silicone resin coating the magnetic carrier core particles; wherein the silicone resin is characterized by having (i) both (a) a --COO-- group and (b) a phenyl group or nitrogen-containing group, (ii) a carbon content attributable to the --COO-- group of 10-70 atomic % of silicon constituting the silicone resin, based on ESCA, and (iii) a carbon content attributable to the phenyl group of 0.1-300 atomic % or a nitrogen content attributable to the nitrogen-containing group of 0.01-10 atomic %, respectively, of the carbon content attributable to the --COO-- group, based on ESCA.

Electrophotographic developer carrier, two-component type developer and

A toner for developing an electrostatic image is disclosed which has toner particles and hydrophobic fine titanium oxide particles. The hydrophobic fine titanium oxide particles have, in X-ray diffraction, an intensity ration Ia/Ib of 5.0.ltoreq.Ia/Ib.ltoreq.12.0 which is a ratio of maximum intensity Ia to minimum intensity Ib within the range of 2.theta.=20.0 to 40.0 deg.

Toner for developing electrostatic image

A magenta toner for developing electrostatic images is formed of a binder resin, and a quinacridone pigment providing an X-ray diffraction spectrum showing two peaks in a Bragg angle (2.theta.) region of 5-10 deg. The magenta toner has an improved light fastness, may have a desired hue comparable to a printing process ink and is suitably used for electrophotographic full-color image formation. The magenta toner may preferably be formed through a process including a first kneading step starting from wet blending of a binder resin and two paste pigments including quinacridone and 2,9-dimethylquinacridone, respectively, under mild conditions not causing crystal transformation to form a master batch and a second kneading step of diluting the master batch together with other additive.

Magenta toner, process for producing same and color image forming method

A toner for developing an electrostatic image is formed from toner particles containing at least a binder resin, a colorant and an organometallic compound. The binder resin in the toner particles has a tetrahydrofuran-insoluble (THF-insoluble) content of at most 5.0 wt.% based on the binder resin. The toner has a glass transition temperature of 50.degree.-80.degree. C. The toner further has storage modulus characteristics including a storage modulus at 80.degree. C. (G'.sub.80) of 1.times.10.sup.4 -5.times.10.sup.6 �dyn/cm.sup.2 !, a storage modulus at 130.degree. C. (G'.sub.130) providing a ratio G'.sub.80 /G'.sub.130 of 10-5.times.10.sup.3, and a storage modulus curve showing a minimum (G'min) in a temperature region of 110.degree.-190.degree. C. The toner especially exhibits excellent low-temperature fixability, anti-high temperature offset characteristic, storage stability and color-miscibility.

Toner for developing electrostatic image and fixing method

An image forming method, including the steps of: forming a toner image with a toner having toner particles and an external additive on a surface of a first image-carrying member which includes a support and a lamination layer disposed thereon containing a peeling layer, fixing the toner image on the surface of the peeling layer of the first image-carrying member to form a fixed image, peeling the peeling layer having the fixed image from the first image-carrying member, and transferring the fixed image on the peeling layer onto a second image-carrying member while swelling the peeling layer, wherein the lamination layer has at least the peeling layer and an adhesive layer, the peeling layer at least including a transfer layer and having an area expansion ratio of 102-106%. The transfer layer may preferably be a composition containing a high-saponified polyvinyl alcohol having a saponification degree of at least 90% and a low-saponified polyvinyl alcohol having a saponification degree of below 90%. The binder resin may preferably be polyester resin having an acid value of 2-25 mg KOH/g. The peeling layer having an appropriate area expansion ratio (102-106%, preferably 102-105%) is effective in allowing quick and uniform peeling thereof from the fixed image.

Image forming and transferring method using a peeling layer

A yellow toner for developing an electrostatic image contains yellow color toner particles having at least a binder resin and a yellow colorant, and an external additive. The binder resin has a polyester resin having an acid value of from 2 mg KOH/g to 25 mg KOH/g and a glass transition temperature of from 52.degree. C. to 65.degree. C. The yellow colorant is a compound represented by the following Formula (I): ##STR1## The external additive is composed of a fine titanium oxide powder or fine aluminum oxide powder subjected to hydrophobic treatment. The powder has an average primary particle diameter of from 0.01 .mu.m to 2 .mu.m. The yellow toner has a weight average particle diameter of from 3.0 .mu.m to 15.0 .mu.m.

Yellow toner for developing electrostatic image, two component

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Kawasaki, Japan

Makoto Kanbayashi