Patents by Inventor Keiji Komoto
Keiji Komoto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20050026061Abstract: In a toner having toner particles containing at least a colorant, a release agent and a polar resin, and an inorganic fine powder, the polar resin contains a polyester resin obtained by carrying out polymerization in the presence of a titanium chelate compound as a catalyst, and has an acid value in a specific range. The toner particles are granulated in an aqueous medium and have a weight-average particle diameter in a specific range.Type: ApplicationFiled: November 21, 2003Publication date: February 3, 2005Inventors: Yushi Mikuriya, Yasushi Katsuta, Keiji Komoto, Takeshi Kaburagi, Emi Tosaka
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Publication number: 20050026063Abstract: A toner includes toner particles and an inorganic fine powder mixed with the toner particles. The toner particles contain a binder resin, a coloring agent, a releasing agent, and a sulfur-containing resin. The toner particles contain at least one element selected from the group consisting of magnesium, calcium, barium, zinc, aluminum, and phosphorus and satisfy the relationship: 4?T/S?30 wherein T represents the total content of the element in ppm, and S represents the content of sulfur in ppm. The weight-average particle diameter (D4) of the toner is in the range of 3 to 10 ?m. The average circularity of the toner is within the range of 0.950 to 0.995.Type: ApplicationFiled: March 25, 2004Publication date: February 3, 2005Inventors: Keiji Komoto, Yasushi Katsuta, Yushi Mikuriya, Takeshi Kaburagi, Emi Tosaka
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Publication number: 20050026062Abstract: In a non-magnetic toner having non-magnetic toner particles containing at least a binder resin and a colorant, and an inorganic fine powder, the non-magnetic toner particles contain at least one ether compound having a specific structure, and the ether compound is in a content of from 5 ppm to 1,000 ppm.Type: ApplicationFiled: January 27, 2004Publication date: February 3, 2005Inventors: Keiji Komoto, Yushi Mikuriya, Yuji Moriki, Yasushi Katsuta, Kenichi Nakayama, Takeshi Kaburagi, Emi Tosaka, Yasuhiro Hashimoto
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Patent number: 6806016Abstract: A toner suitable for use in electrophotography, etc., is composed of toner particles each containing a binder resin, a colorant and a wax component. The toner has a number-average particle size of 2-6 &mgr;m and a standard deviation in particle size of below 2.6 &mgr;m based on a number-basis distribution of circle-equivalent diameters, an average circularity of 0.970-0.995 and a standard deviation in circularity of below 0.030 based on a circularity frequency distribution, and a residual monomer content of at most 500 ppm. The toner particles have such a microtexture as to provide a particle cross section as observed through a transmission electron microscope (TEM) exhibiting a matrix of the binder resin and a particle of the wax dispersed in a discrete form in the matrix of the binder resin.Type: GrantFiled: January 29, 2003Date of Patent: October 19, 2004Assignee: Canon Kabushiki KaishaInventors: Manabu Ohno, Satoshi Yoshida, Satoshi Handa, Akira Hashimoto, Keiji Komoto
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Publication number: 20040191659Abstract: A toner having a favorable fixability, excelling in charge stability, and capable of forming a image of retaining a high image density and a high resolution in long-term use is provided. That is, the toner of the present invention is a toner obtained by polymerizing a polymerizable monomer composition comprising a polymerizable monomer and a colorant, in which the polymerizable monomer composition is polymerized using a polymerization initiator comprising a redox initiator which includes an organic peroxide with a 10-hour half-life temperature of 86° C. or higher and an reducing agent; the toner has a ratio of a weight-average particle diameter to a number-average particle diameter of 1.40 or less; and the toner has top of a main-peak in a molecular weight range of 5,000 to 50,000 in a molecular weight distribution measured using GPC of the THF-soluble part thereof, including t-butanol with a content of 0.1 to 1,000 ppm.Type: ApplicationFiled: December 4, 2003Publication date: September 30, 2004Inventors: Tatsuya Nakamura, Kenji Okado, Akira Hashimoto, Keiji Komoto
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Publication number: 20040018028Abstract: To provide an method for forming image in which the image bearing member and the toner carrying member are arranged with a gap of 100 &mgr;m to 250 &mgr;m; equation (1) and equation (2) are satisfied: (1) 22≦(the frequency of the alternating current component of the alternating electric field/the peripheral speed of the toner carrying member)×the maximum electric field intensity at the time of developing≦120; (2) 8≦(the frequency of the alternating current component of the alternating electric field/the peripheral speed of toner carrying member)×(the fluidity index of Carr/the floodability index of Carr)≦50. According to method for forming image of the present invention, it is possible to obtain a high quality image without generating fog and light shielding while attaining a uniform halftone with a high image density even in a long-term use.Type: ApplicationFiled: June 18, 2003Publication date: January 29, 2004Applicant: CANON KABUSHIKI KAISHAInventors: Tatsuhiko Chiba, Michihisa Magome, Keiji Komoto, Kaori Hiratsuka, Takeshi Kaburagi
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Patent number: 6653035Abstract: A magnetic toner exhibiting stable performances under various environmental conditions is formed of toner particles each comprising at least a binder resin and iron oxide dispersed therein. Relative to the dry specific gravity (A) of the magnetic toner, the magnetic toner is characterized by a specific gravity distribution of toner particle fractions obtainable through wet sedimentation and including: at most 15 wt. % of a fraction having a specific gravity of above (A)×1.000 and at most (A)×1.025, 0.1-20 wt. % of a fraction having a specific gravity of above (A)×0.975 and at most (A)×1.000, at least 30 wt. % of a fraction having a specific gravity of above (A)×0.950 and at most (A)×0.975, 0.1-20 wt. % of a fraction having a specific gravity of above (A)×0.925 and at most (A)×0.950, and at most 15 wt. % of a fraction having a specific gravity of above (A)×0.900 and at most (A)×0.925.Type: GrantFiled: July 26, 2002Date of Patent: November 25, 2003Assignee: Canon Kabushiki KaishaInventors: Keiji Komoto, Tatsuya Nakamura, Tatsuhiko Chiba, Michihisa Magome, Akira Hashimoto, Takeshi Kaburagi, Eriko Yanase
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Patent number: 6638674Abstract: A magnetic toner is formed of magnetic toner particles each comprising a binder resin, an iron oxide, a sulfur-containing polymer, and inorganic fine powder blended with the magnetic toner particles, the toner having a weight-average particle size (D4) of 3-10 &mgr;m, and either (a) an average circularity of at least 0.970, and a magnetization of 10-50 Am2/kg (emu/g) at a magnetic field of 79.6 kA/m (1000 oersted), or (b) toner particles which retain carbon in an amount of A and iron in an amount of B at surfaces thereof, satisfying: B/A<0.001, and containing at least 50% by number of magnetic toner particles of D/C≦0.02, wherein C represents a particle projection area-equivalent circle diameter and D represents a minimum distance between a surface of the magnetic toner particle and iron oxide particles contained therein.Type: GrantFiled: July 25, 2001Date of Patent: October 28, 2003Assignee: Canon Kabushiki KaishaInventors: Keiji Komoto, Tsuyoshi Takiguchi, Tatsuhiko Chiba, Michihisa Magome, Akira Hashimoto, Takeshi Kaburagi, Eriko Yanase
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Patent number: 6635398Abstract: A dry toner has toner particles containing at least a binder resin, a colorant and a wax component and an external additive. The binder resin contains a component derived from a monomer selected from butadiene, isoprene and chloroprene. The toner has a main Tg from 40° C. to 70° C. When specific surface area measured by the BET method in an environment of 23° C. atmospheric temperature and 65% relative humidity is represented by A (m2/g) and specific surface area measured by the BET method in an environment of 50° C. atmospheric temperature and 3% relative humidity is represented by B (m2/g), the toner satisfies the following relationship: 0.8≦A≦4.0, 0.80≦(B/A)≦1.05. The toner has a circle-corresponding number-average particle diameter D1 from 2 to 10 &mgr;m, an average circularity from 0.950 to 0.995 and a circularity standard deviation less than 0.040. The toner has a main-peak molecular weight from 2,000 to 100,000 and contains a THF-insoluble matter from 5 to 60% by weight.Type: GrantFiled: October 25, 2000Date of Patent: October 21, 2003Assignee: Canon Kabushiki KaishaInventors: Keiji Komoto, Tsutomu Kukimoto, Tatsuhiko Chiba, Akira Hashimoto
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Publication number: 20030186152Abstract: A toner suitable for use in electrophotography, etc., is composed of toner particles each containing a binder resin, a colorant and a wax component. The toner has a number-average particle size of 2-6 &mgr;m and a standard deviation in particle size of below 2.6 based on a number-basis distribution of circle-equivalent diameters, an average circularity of 0.970-0.995 and a standard deviation in circularity of below 0.030 based on a circularity frequency distribution, and a residual monomer content of at most 500 ppm. The toner particles have such a microtexture as to provide a particle cross section as observed through a transmission electron microscope (TEM) exhibiting a matrix of the binder resin and a particle of the wax dispersed in a discrete form in the matrix of the binder resin.Type: ApplicationFiled: January 29, 2003Publication date: October 2, 2003Inventors: Manabu Ohno, Satoshi Yoshida, Satoshi Handa, Akira Hashimoto, Keiji Komoto
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Patent number: 6610454Abstract: A toner is comprised of a binder resin, a colorant and a wax. The binder resin has a polycarbonate resin in an amount of from 0.1% by weight to 50.0% by weight and a resin other than the polycarbonate resin in an amount of from 50.0% by weight to 99.9% by weight, based on the weight of the binder resin. In molecular weight distribution as measured by gel permeation chromatography of tetrahydrofuran-soluble matter, the toner contains in an amount of 15.0% by weight or less based on the weight of the toner a component which has in its structure a repeating unit of the polycarbonate resin and is contained in components having a molecular weight of 1,000 or less.Type: GrantFiled: September 3, 1998Date of Patent: August 26, 2003Assignee: Canon Kabushiki KaishaInventors: Akira Hashimoto, Tsutomu Kukimoto, Manabu Ohno, Tsuyoshi Takiguchi, Yasukazu Ayaki, Satoshi Handa, Masanori Ito, Keiji Komoto
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Patent number: 6596452Abstract: A magnetic toner comprising magnetic toner particles containing at least a binder resin, a magnetic material containing a magnetic iron oxide, and a release agent. The magnetic toner has a weight-average particle diameter of from 3 &mgr;m to 10 &mgr;m, a magnetization intensity (saturation magnetization) of from 10 Am2/kg to 50 Am2/kg (emu/g) under application of a magnetic field of 79.6 kA/m (1,000 oersteds), an average circularity of 0.970 or more, a ratio of weight-average particle diameter to number-average particle diameter, of 1.40 or less, iron and an iron compound which stand liberated from the magnetic toner particles at a liberation percentage of from 0.05% to 3.00%, and a resin component having a tetrahydrofuran-insoluble matter in an amount of from 3% by weight to 60% by weight. Also disclosed is an image-forming method making use of the magnetic toner.Type: GrantFiled: February 21, 2001Date of Patent: July 22, 2003Assignee: Canon Kabushiki KaishaInventors: Michihisa Magome, Tsutomu Kukimoto, Tsuyoshi Takiguchi, Tatsuhiko Chiba, Akira Hashimoto, Keiji Komoto
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Patent number: 6544708Abstract: An image forming method using a dry toner and exhibiting good quick-start and power economization characteristics is provided. The image forming method includes a heat-pressure fixing step using a rotatable electromagnetic induction heat-generation type heating member. The toner used therein is characterized by a moisture content of at most 3.00 wt. %, and viscoelasticities as represented by a storage modulus at 110° C. of G′ (110° C.) and a storage modulus at 140° C. of G′ (140° C.) satisfying: G′ (110° C.)≦1.00×106 dN/m2, and G′ (140° C.)≧7.00×103 dN/m3.Type: GrantFiled: March 27, 2001Date of Patent: April 8, 2003Assignee: Canon Kabushiki KaishaInventors: Keiji Komoto, Hiroaki Kawakami, Tatsuhiko Chiba, Atsuyoshi Abe, Yuji Moriki, Michihisa Magome, Satoshi Handa, Kiyokazu Suzuki
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Publication number: 20030064309Abstract: A magnetic toner exhibiting stable performances under various environmental conditions is formed of toner particles each comprising at least a binder resin and iron oxide dispersed therein. Relative to the dry specific gravity (A) of the magnetic toner, the magnetic toner is characterized by a specific gravity distribution of toner particle fractions obtainable through wet sedimentation and including: at most 15 wt. % of a fraction having a specific gravity of above (A)×1.000 and at most (A)×1.025, 0.1-20 wt. % of a fraction having a specific gravity of above (A)×0.975 and at most (A)×1.000, at least 30 wt. % of a fraction having a specific gravity of above (A)×0.950 and at most (A)×0.975, 0.1-20 wt. % of a fraction having a specific gravity of above (A)×0.925 and at most (A)×0.950, and at most 15 wt. % of a fraction having a specific gravity of above (A)×0.900 and at most (A)×0.925.Type: ApplicationFiled: July 26, 2002Publication date: April 3, 2003Inventors: Keiji Komoto, Tatsuya Nakamura, Tatsuhiko Chiba, Michihisa Magome, Akira Hashimoto, Takeshi Kaburagi, Eriko Yanase
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Patent number: 6528224Abstract: A toner suitable for use in electrophotography, etc., is composed of toner particles each containing a binder resin, a colorant and a wax component. The toner has a number-average particle size of 2-6 &mgr;m and a standard deviation in particle size of below 2.6 &mgr;m based on a number-basis distribution of circle-equivalent diameters, an average circularity of 0.970-0.995 and a standard deviation in circularity of below 0.030 based on a circularity frequency distribution, and a residual monomer content of at most 500 ppm. The toner particles have such a microtexture as to provide a particle cross section as observed through a transmission electron microscope (TEM) exhibiting a matrix of the binder resin and a particle of the wax dispersed in a discrete form in the matrix of the binder resin.Type: GrantFiled: March 30, 1999Date of Patent: March 4, 2003Inventors: Manabu Ohno, Satoshi Yoshida, Satoshi Handa, Akira Hashimoto, Keiji Komoto
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Patent number: 6465144Abstract: A magnetic toner includes: magnetic toner particles each comprising at least a binder resin and magnetic toner, and inorganic fine powder. The magnetic toner has an average circularity of at least 0.970, and a magnetization of 10-50 Am2/kg at a magnetic field of 79.6 kA/m. The magnetic powder comprises at least magnetic iron oxide. The magnetic toner particles retain carbon in an amount of A and iron in an amount of B at surfaces thereof as measured by X-ray photoelectron spectroscopy, satisfying: B/A<0.001. The binder resin comprises a resin formed by polymerization of a monomer comprising at least styrene monomer. The magnetic toner has a residual styrene monomer content of less than 300 ppm, and contains at least 50% by number of toner particles satisfying a relationship of: D/C≦0.Type: GrantFiled: March 8, 2001Date of Patent: October 15, 2002Assignee: Canon Kabushiki KaishaInventors: Akira Hashimoto, Kenji Okado, Tsutomu Kukimoto, Tatsuya Nakamura, Tsuyoshi Takiguchi, Tatsuhiko Chiba, Michihisa Magome, Keiji Komoto
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Patent number: 6447969Abstract: A toner is formed of toner particles each comprising a binder resin and iron oxide particles dispersed therein. The toner particles are characterized by uniform but non-surface-exposed dispersion of the iron oxide particles within the toner particles as represented by (i) a carbon content (A) and an iron content (B) giving a ratio B/A<0.001 at surfaces of the toner particles as measured by X-ray photoelectron spectroscopy, (ii) an average circularity of at least 0.970, and (iii) at least 50% by number of toner particles satisfying D/C≦0.02, wherein C denotes a projection area-equivalent circular diameter of each toner particle and D denotes a minimum distance of iron oxide particles from a surface of the toner particle, based on a sectional view of the toner particle as observed through a transmission electron microscope (TEM).Type: GrantFiled: May 30, 2000Date of Patent: September 10, 2002Assignee: Canon Kabushiki KaishaInventors: Masanori Ito, Tsutomu Kukimoto, Tsuyoshi Takiguchi, Tatsuhiko Chiba, Michihisa Magome, Akira Hashimoto, Keiji Komoto
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Publication number: 20020115011Abstract: In an image forming system, an image-bearing member having a photoconductor layer comprising an Si-based non-single crystal material is charged at a relatively low potential of 250 to 600 volts by a contact charging member in the presence of electroconductive fine powder. An electrostatic latent image formed on the image-bearing member is developed with a magnetic toner which includes magnetic toner particles comprising at least a binder resin and a magnetic iron oxide, and inorganic fine powder and electroconductive fine powder present at the surface of the magnetic toner particles. The magnetic toner has a weight-average particle size of 3-10 &mgr;m and an average circularity of 0.950 to 0.995, and contains 0.05 to 3.00 % of isolated iron-containing particles.Type: ApplicationFiled: November 15, 2001Publication date: August 22, 2002Inventors: Keiji Komoto, Tsuyoshi Takiguchi, Tatsuhiko Chiba, Michihisa Magome, Akira Hashimoto, Takeshi Kaburagi
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Publication number: 20020055052Abstract: A magnetic toner capable of exhibiting stable chargeability regardless of environmental change is formed of magnetic toner particles each comprising at least a binder resin, an iron oxide and a sulfur-containing polymer, and inorganic fine powder blended with the magnetic toner particles. The magnetic toner is also provided with good developing performance and high transferability by satisfying a weight-average particle size (D4) of 3-10 &mgr;m, an average circularity of at least 0.970, and a magnetization of 10-50 Am2/kg (emu/g) at a magnetic field of 79.6 kA/m (1000 oersted). The magnetic toner is further characterized in that the magnetic toner particles retain carbon in an amount of A and iron in an amount of B at surfaces thereof as measured by X-ray photoelectron spectroscopy, satisfying: B/A<0.001, and the magnetic toner contains at least 50% by number of magnetic toner particles satisfying a relationship of D/C≦0.Type: ApplicationFiled: July 25, 2001Publication date: May 9, 2002Inventors: Keiji Komoto, Tsuyoshi Takiguchi, Tatsuhiko Chiba, Michihisa Magome, Akira Hashimoto, Takeshi Kaburagi, Eriko Yanase
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Publication number: 20020048713Abstract: An image forming method using a dry toner and exhibiting good quick-start and power economization characteristics is provided. The image forming method includes a heat-pressure fixing step using a rotatable electromagnetic induction heat-generation type heating member. The toner used therein is characterized by a moisture content of at most 3.00 wt. %, and viscoelasticities as represented by a storage modulus at 110° C. of G′ (110° C.) and a storage modulus at 140° C. of G′ (140° C.) satisfying: G′ (110° C.)≦1.00×106 dN/m2, and G′ (140° C.)≧7.00×103 dN/m3.Type: ApplicationFiled: March 27, 2001Publication date: April 25, 2002Inventors: Keiji Komoto, Hiroaki Kawakami, Tatsuhiko Chiba, Atsuyoshi Abe, Yuji Moriki, Michihisa Magome, Satoshi Handa, Kiyokazu Suzuki