Patents by Inventor Shuichi Hiroko
Shuichi Hiroko 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: 20140030645Abstract: Disclosed is a toner which enables a stable image density to be obtained, regardless of the service environment, throughout use in durability tests, and which is able to suppress the occurrence of faulty cleaning. The toner contains both toner particles, which include a binder resin and a colorant, and also silica fine particles. The toner has an average circularity of at least 0.950, a static friction coefficient, with respect to a polycarbonate resin substrate, of at least 0.100 and not more than 0.200, and a coverage ratio X1 of the toner surface by the silica fine particles, as determined by X-ray photoelectron spectroscopy (ESCA), of at least 50.0 area %, and not more than 75.0 area %.Type: ApplicationFiled: September 30, 2013Publication date: January 30, 2014Applicant: CANON KABUSHIKI KAISHAInventors: Shotaro Nomura, Yusuke Hasegawa, Takashi Matsui, Shuichi Hiroko, Yoshitaka Suzumura, Atsuhiko Ohmori
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Patent number: 8614044Abstract: To provide a toner which can achieve both low-temperature fixing performance and dot reproducibility and further can obtain images on which any density non-uniformity has been kept from coming about, the toner has toner particles, each of the toner particles has a toner base particle containing a binder resin, a colorant and a release agent, and an inorganic fine powder; the toner having: (1) an average circularity of 0.960 or more; (2) a number-average molecular weight Mn(25° C.) of from 500 or more to 3,000 or less in measuring a tetrahydrofuran-soluble matter at 25° C. of the toner by SEC-MALLS; and (3) a value of Mn(135° C.)/Mn(25° C.) of from 25 or more to 50 or less which is the ratio of number-average molecular weight Mn(135° C.) in measuring an o-dichlorobenzene-soluble matter at 135° C. of the toner by SEC-MALLS to number-average molecular weight Mn(25° C.) in measuring a tetrahydrofuran-soluble matter at 25° C. of the toner by SEC-MALLS.Type: GrantFiled: June 13, 2011Date of Patent: December 24, 2013Assignee: Canon Kabushiki KaishaInventors: Takashi Matsui, Michihisa Magome, Yusuke Hasegawa, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura, Atsuhiko Ohmori
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Publication number: 20130143154Abstract: A toner with good low-temperature fixability even in light-pressure type fixing units, which causes no contamination of fixing films and provides images having stable image densities and excellent image quality after long-term use. The toner includes a toner particle containing a binder resin, a coloring agent, a release agents (a) and (b) The release agent (a) is a monofunctional or bifunctional ester wax; the release agent (b) is a hydrocarbon wax; a solubility of the release agent (a) into the binder resin is higher than that of the release agent (b). When tetrahydrofuran-soluble components of the toner are subjected to GPC, a proportion of components having a molecular weight of 500 or less is 2.5 area % or less. When the tetrahydrofuran-soluble components at 25° C. are subjected to SEC-MALLS, a weight-average molecular weight Mw thereof is 5,000-100,000, and the Mw and the radius of gyration Rw thereof satisfy 5.0×10?4?Rw/Mw?1.0×10?2.Type: ApplicationFiled: September 9, 2011Publication date: June 6, 2013Applicant: Canon Kabushiki KaishaInventors: Takashi Matsui, Michihisa Magome, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura
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Patent number: 8426094Abstract: A magnetic toner has magnetic toner particles, each of the magnetic toner particles containing a binder resin and a magnetic material, and an inorganic fine powder. The magnetic material is prepared by treating the surface of magnetic iron oxide with a silane compound. When the magnetic iron oxide is dispersed in an aqueous solution of hydrochloric acid and dissolved until the dissolution proportion of the iron element reaches 5% by mass based on the total amount of the iron element contained in the magnetic iron oxide, the amount of silicon eluted by that point of time is 0.05% by mass or more and 0.50% by mass or less based on the magnetic iron oxide. The magnetic material has a moisture adsorption amount per unit area of 0.30 mg/m2 or less.Type: GrantFiled: May 25, 2011Date of Patent: April 23, 2013Assignee: Canon Kabushiki KaishaInventors: Michihisa Magome, Takashi Matsui, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura
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Patent number: 8426091Abstract: To solve a thin image density and sweeping occurring when a toner carrying member having a small diameter is used, provided is an image-forming method including: a charging step; an electrostatic latent image-forming step; a developing step; a transferring step; and a fixing step, in which a magnetic toner to be used in the method has a specific weight average particle diameter (D4); the magnetic toner has a specific intensity of magnetization in a specific magnetic field; and a surface free energy of a surface of the magnetic toner and a surface free energy of a surface of a toner carrying member to be used in the method satisfy specific relationships.Type: GrantFiled: October 29, 2008Date of Patent: April 23, 2013Assignee: Canon Kabushiki KaishaInventors: Michihisa Magome, Tadashi Dojo, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Shuichi Hiroko
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Patent number: 8227162Abstract: To provide a toner excellent in low-temperature fixability, releasing performance, and development stability in long-term use under a high-temperature and high-humidity environment, provided is a magnetic toner including: magnetic toner particles each containing at least a binder resin and a magnetic particles; and an inorganic fine powder, in which: the magnetic particles is a treated magnetic particles treated with a silane compound; the treated magnetic particles has a water adsorption per unit area based on a BET specific surface area of 0.300 mg/m2 or less; portion of styrene extractables constitutes 25 mass % or less among the silane compound in the treated magnetic particles; and the silane compound with which the treated magnetic particles is treated contains a compound having a hydrocarbon group having 2 or more and 4 or less carbon atoms as a main component.Type: GrantFiled: April 6, 2010Date of Patent: July 24, 2012Assignee: Canon Kabushiki KaishaInventors: Tomohisa Sano, Michihisa Magome, Takashi Matsui, Akira Sakakibara, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura
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Publication number: 20120045717Abstract: A magnetic toner is provided that exhibits an excellent dot reproducibility and developing performance after being allowed to stand in a high temperature and high humidity environment and an excellent low-temperature fixability. The magnetic toner has an inorganic fine powder and a magnetic toner particle containing a binder resin, a magnetic body, and a release agent, wherein in a stress relaxation measurement using a rotating plate rheometer, the magnetic toner exhibits a yield value A at 25° C. of at least 3×106 (sec), and the magnetic toner that has been heated to 80° C. and then cooled to 25° C. exhibits a yield value B at 25° C. of not more than 1×105 (sec).Type: ApplicationFiled: August 8, 2011Publication date: February 23, 2012Applicant: CANON KABUSHIKI KAISHAInventors: Shuichi Hiroko, Yoshihiro Nakagawa, Tomohisa Sano
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Publication number: 20110311910Abstract: To provide a toner which can achieve both low-temperature fixing performance and dot reproducibility and further can obtain images on which any density non-uniformity has been kept from coming about, the toner has toner particles, each of the toner particles has a toner base particle containing a binder resin, a colorant and a release agent, and an inorganic fine powder; the toner having: (1) an average circularity of 0.960 or more; (2) a number-average molecular weight Mn(25° C.) of from 500 or more to 3,000 or less in measuring a tetrahydrofuran-soluble matter at 25° C. of the toner by SEC-MALLS; and (3) a value of Mn(135° C.)/Mn(25° C.) of from 25 or more to 50 or less which is the ratio of number-average molecular weight Mn(135° C.) in measuring an o-dichlorobenzene-soluble matter at 135° C. of the toner by SEC-MALLS to number-average molecular weight Mn(25° C.) in measuring a tetrahydrofuran-soluble matter at 25° C. of the toner by SEC-MALLS.Type: ApplicationFiled: June 13, 2011Publication date: December 22, 2011Applicant: CANON KABUSHIKI KAISHAInventors: Takashi Matsui, Michihisa Magome, Yusuke Hasegawa, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura, Atsuhiko Ohmori
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Publication number: 20110294056Abstract: A magnetic toner has magnetic toner particles, each of the magnetic toner particles containing a binder resin and a magnetic material, and an inorganic fine powder. The magnetic material is prepared by treating the surface of magnetic iron oxide with a silane compound. When the magnetic iron oxide is dispersed in an aqueous solution of hydrochloric acid and dissolved until the dissolution proportion of the iron element reaches 5% by mass based on the total amount of the iron element contained in the magnetic iron oxide, the amount of silicon eluted by that point of time is 0.05% by mass or more and 0.50% by mass or less based on the magnetic iron oxide. The magnetic material has a moisture adsorption amount per unit area of 0.30 mg/m2 or less.Type: ApplicationFiled: May 25, 2011Publication date: December 1, 2011Applicant: CANON KABUSHIKI KAISHAInventors: Michihisa Magome, Takashi Matsui, Tomohisa Sano, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura
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Patent number: 8026030Abstract: The present invention provides a toner which is excellent in low-temperature fixability and transparency and has high gloss, and which is excellent in offset resistance, storage stability, and development stability. The toner is characterized in that: a square radius of inertia Rt at a peak top of a main peak in GPC-RALLS-viscometer analysis of tetrahydrofuran (THF) soluble matter when the toner is dissolved in a THF solvent at 25° C. for 24 hours is 1.0 nm to 3.8 nm; and the square radius of inertia Rt and a square radius of inertia Rp at a peak top of a main peak in GPC-RALLS-viscometer analysis of THF soluble matter when linear polystyrene, having an absolute peak molecular weight value at the same value as a main peak value of the toner, is dissolved in a THF solvent at 25° C. for 24 hours satisfy the relationship of Rt/Rp<0.85.Type: GrantFiled: November 3, 2006Date of Patent: September 27, 2011Assignee: Canon Kabushiki KaishaInventors: Syuhei Moribe, Katsuhisa Yamazaki, Shuichi Hiroko
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Patent number: 7935467Abstract: In a magnetic toner which has magnetic toner base particles containing at least a binder resin and a magnetic material, and an inorganic fine powder, (i) the magnetic toner has an average circularity of from 0.950 or more to 1.000 or less, (ii) the magnetic toner has a compressibility of 30 or less, and (iii) the magnetic toner contains boron nitride particles having a median diameter (D50) of from 0.5 ?m or more to 8.0 ?m or less, as the inorganic fine powder in an amount of from 0.05 part by mass or more to 1.00 part by mass or less based on 100 parts by mass of the magnetic toner base particles. This provides a magnetic toner with which stable image density can be achieved without regard to service environment and which do not cause any image defects such as fog.Type: GrantFiled: November 18, 2008Date of Patent: May 3, 2011Assignee: Canon Kabushiki KaishaInventors: Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko
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Patent number: 7923190Abstract: In a toner containing at least a binder resin, a colorant, an ester compound and a low-melting material, the ester compound is an ester of dipentaerythritol with a carboxylic acid having 18 or more to 25 or less carbon atoms, and, where the melting point of the ester compound is represented by Tm(A) (° C.) and the melting point of the low-melting material is represented by Tm(B) (° C.), the toner satisfies the relationship of: Tm(B)?Tm(A)+5.Type: GrantFiled: October 13, 2009Date of Patent: April 12, 2011Assignee: Canon Kabushiki KaishaInventors: Michihisa Magome, Tadashi Dojo, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko
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Patent number: 7897316Abstract: Provided is a toner including at least: a binder resin; and a colorant, in which: the binder resin contains at least a polyester unit and a vinyl copolymer unit; a main peak MpA is present in the molecular weight region of 2,000 to 7,000 in a molecular weight distribution measured by means of gel permeation chromatography (GPC) of a specific tetrahydrofuran (THF) soluble matter A measured by a specific method; a main peak MpB is present in the molecular weight region of 5,000 to 10,000 in a molecular weight distribution measured by means of GPC of a specific THF soluble matter B which contains a component of a molecular weight region of 100,000 or less in range from 70 to 100 mass %, and the peak molecular weight MpA of the THF soluble matter A and the peak molecular weight MpB of the THF soluble matter B satisfy a specific equation.Type: GrantFiled: July 24, 2006Date of Patent: March 1, 2011Assignee: Canon Kabushiki KaishaInventors: Katsuhisa Yamazaki, Masami Fujimoto, Shuichi Hiroko, Masaaki Taya
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Publication number: 20100266943Abstract: To provide a toner excellent in low-temperature fixability, releasing performance, and development stability in long-term use under a high-temperature and high-humidity environment, provided is a magnetic toner including: magnetic toner particles each containing at least a binder resin and a magnetic particles; and an inorganic fine powder, in which: the magnetic particles is a treated magnetic particles treated with a silane compound; the treated magnetic particles has a water adsorption per unit area based on a BET specific surface area of 0.300 mg/m2 or less; portion of styrene extractables constitutes 25 mass % or less among the silane compound in the treated magnetic particles; and the silane compound with which the treated magnetic particles is treated contains a compound having a hydrocarbon group having 2 or more and 4 or less carbon atoms as a main component.Type: ApplicationFiled: April 6, 2010Publication date: October 21, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Tomohisa Sano, Michihisa Magome, Takashi Matsui, Akira Sakakibara, Shuichi Hiroko, Yoshitaka Suzumura, Shotaro Nomura
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Patent number: 7678523Abstract: To provide a magnetic toner which has superior low-temperature fixing performance and pressure roller anti-staining properties even in various forms of use, has been kept from image defects such as image non-uniformity even during long-time image reproduction and can achieve high-level image quality. In a magnetic toner having toner particles containing at least a binder resin and a magnetic material, the activation energy Ea (kJ/mol) that is determined from a shift factor aT120 in a master curve of the toner, prepared when 120° C. is set as reference temperature, and the activation energy Eb (kJ/mol) that is determined from a shift factor aT150 in a master curve of the toner, prepared when 150° C. is set as reference temperature, satisfy Expression (1), and the Ea is 110 kJ/mol or less: 1.00?Ea/Eb<1.20??(1).Type: GrantFiled: December 9, 2008Date of Patent: March 16, 2010Assignee: Canon Kabushiki KaishaInventors: Shuichi Hiroko, Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara
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Publication number: 20100028795Abstract: In a toner containing at least a binder resin, a colorant, an ester compound and a low-melting material, the ester compound is an ester of dipentaerythritol with a carboxylic acid having 18 or more to 25 or less carbon atoms, and, where the melting point of the ester compound is represented by Tm(A) (° C.) and the melting point of the low-melting material is represented by Tm(B) (° C.), the toner satisfies the relationship of: Tm(B)?Tm(A)+5.Type: ApplicationFiled: October 13, 2009Publication date: February 4, 2010Applicant: CANON KABUSHIKI KAISHAInventors: Michihisa Magome, Tadashi Dojo, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko
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Patent number: 7638251Abstract: The invention provides a toner which is excellent in its low-temperature fixing property and high-temperature offset resistance regardless of the types of paper, and constantly provides high-quality images regardless of environments and does not generate image defects even after prolonged use. In a master curve of the toner at a reference temperature of 150° C., a difference between a storage modulus at a frequency of 0.1 Hz and a storage modulus at a frequency of 1000 Hz is set in a rage from 0 to 2.5×105 Pa, where the activation energy determined from a shift factor is brought to a range from 50 to 130 kJ/mol.Type: GrantFiled: February 6, 2007Date of Patent: December 29, 2009Assignee: Canon Kabushiki KaishaInventors: Katsuhisa Yamazaki, Shuichi Hiroko, Shuhei Moribe
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Publication number: 20090197192Abstract: A magnetic toner having magnetic toner particles containing at least a binder resin and a magnetic material, wherein, in the test of dissolution level of the magnetic material, the dissolution percentages S3 (% by mass), S15 (% by mass) and S30 (% by mass), and the dissolution level proportion Sc satisfy the following expressions: 0.5?S3?10, 40?S15?80, 1.2?Sc[=(S15?S3)/(S30?S15)]?10; and the magnetic toner has a dielectric loss factor (tan ?) at 25° C. and at a frequency 1.0×104 Hz, within the range of from 2.0×10?3 or more to 1.5×10?2 or less.Type: ApplicationFiled: April 9, 2009Publication date: August 6, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Shuichi Hiroko, Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Yoshitaka Suzumura
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Patent number: 7537877Abstract: A toner is provided which can stably provide a favorable density stability, line reproducibility and dot reproducibility even in high-speed copying machines, printers and the like which form high resolution latent images over a long period regardless of environmental conditions, and can provide the image quality adaptable to embedded pattern printing, QR code printing and the like. The present invention is characterized in that the toner which includes toner particles including at least a binder resin and a colorant, and a fine silica powder, has a volume median diameter (D50) of not less than 0.70 ?m and not more than 3.00 ?m, and a total pore volume of not more than 0.200 cm3/g, measured in the range of the pore diameter from not less than 1.7 nm and not more than 300.0 nm.Type: GrantFiled: November 29, 2007Date of Patent: May 26, 2009Assignee: Canon Kabushiki KaishaInventors: Daisuke Yoshiba, Katsuhisa Yamazaki, Syuhei Moribe, Junko Nishiyama, Shuichi Hiroko, Masami Fujimoto, Takashige Kasuya
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Publication number: 20090130580Abstract: In a magnetic toner which has magnetic toner base particles containing at least a binder resin and a magnetic material, and an inorganic fine powder, (i) the magnetic toner has an average circularity of from 0.950 or more to 1.000 or less, (ii) the magnetic toner has a compressibility of 30 or less, and (iii) the magnetic toner contains boron nitride particles having a median diameter (D50) of from 0.5 ?m or more to 8.0 ?m or less, as the inorganic fine powder in an amount of from 0.05 part by mass or more to 1.00 part by mass or less based on 100 parts by mass of the magnetic toner base particles. This provides a magnetic toner with which stable image density can be achieved without regard to service environment and which do not cause any image defects such as fog.Type: ApplicationFiled: November 18, 2008Publication date: May 21, 2009Applicant: CANON KABUSHIKI KAISHAInventors: Tadashi Dojo, Michihisa Magome, Eriko Yanase, Takashi Matsui, Tomohisa Sano, Akira Sakakibara, Shuichi Hiroko