Patents by Inventor Makoto Unno
Makoto Unno 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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Patent number: 5604072Abstract: 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.Type: GrantFiled: September 19, 1995Date of Patent: February 18, 1997Assignee: Canon Kabushiki KaishaInventors: Makoto Unno, Takaaki Kotaki, Yushi Mikuriya, Tadashi Dojyo
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Patent number: 5578409Abstract: A toner for developing an electrostatic image has a binder resin and a colorant.The binder resin contains a polyester resin at least part of which has a long-chain alkyl group having 22 to carbon atoms and has a hydroxyl group or a carboxyl group at its terminal.Type: GrantFiled: November 15, 1995Date of Patent: November 26, 1996Assignee: Canon Kabushiki KaishaInventors: Takaaki Kotaki, Masaaki Taya, Makoto Unno, Yushi Mikuriya, Tadashi Dojyo
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Patent number: 5578408Abstract: A toner for developing an electrostatic image is constituted by a binder resin and a colorant. The toner is characterized by a percentage change .sub.G' of at most 50% as calculated by the following formula (1):.gamma..sub.G' =(1-G'.sub.50% /G'.sub.1%).times.100 (1),wherein .gamma..sub.G' denotes a percentage change of storage modulus, G'.sub.50% denotes a storage modulus at 50% strain at 150.degree. C., and G'.sub.1% denotes a storage modulus at 1% strain at 150.degree. C.; a percentage change .gamma..sub.G" of at most 50% as calculated by the following formula (2):.gamma..sub.G" =(1-G".sub.50% /G".sub.1%).times.100 (2),wherein .gamma..sub.G" denotes a percentage change of loss modulus, G".sub.50% denotes a loss modulus at 50% strain, and G".sub.1% denotes a loss modulus at 1% strain; and a storage modulus G' of 3.times.10.sup.3 -7.times.10.sup.4 dyn/cm.sup.2 in a range of 1-50% strain at 150.degree. C.Type: GrantFiled: December 29, 1994Date of Patent: November 26, 1996Assignee: Canon Kabushiki KaishaInventors: Takaaki Kohtaki, Masaaki Taya, Makoto Unno, Tadashi Doujo
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Patent number: 5504272Abstract: An image forming method in which a toner-carrying member for carrying a specific magnetic toner is placed adjacent a latent image-bearing member for carrying an electrostatic latent image so as to form a developing region of a predetermined gap size. The magnetic toner on the toner-carrying member forms a toner layer of a regulated thickness smaller than the above-mentioned gap. An asymmetric bias is applied to the magnetic toner so as to cause the magnetic toner from the toner-carrying member to be conveyed to the latent image-bearing member thereby to develop the electrostatic latent image.Type: GrantFiled: May 20, 1994Date of Patent: April 2, 1996Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Hirohide Tanikawa, Yasutaka Akashi, Masaaki Taya, Makoto Unno
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Patent number: 5500318Abstract: A toner for developing an electrostatic image is constituted by a binder resin and a colorant The binder resin is characterized by containing at least 20 wt. % of an extraction residue after 6 hours of extraction and below 20 wt. % of an extraction residue after 72 hours of extraction respectively by Soxhlet extraction with tetrahydrofuran. The toner shows a dynamic modulus and a loss modulus, respectively at 200.degree. C. and 0.1 Hz, which are substantially unchanging with time. The properties provide the toner with a harmonization of anti-offset characteristic and fixability as well as stable viscoelasticity under heating.Type: GrantFiled: June 27, 1994Date of Patent: March 19, 1996Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Masaki Uchiyama, Yoshinobu Joh, Yasutaka Akashi, Masaaki Taya, Makoto Unno
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Patent number: 5483327Abstract: An image forming apparatus and a process cartridge includes a toner for developing an electrostatic image that is constituted by at least a binder resin and a charge control agent. The binder resin has an acid value of 5-50. The charge control agent includes an iron complex represented by the following formula: ##STR1## wherein X.sub.1 and X.sub.2 independently denote hydrogen atom, lower alkyl group, lower alkoxy group, nitro group or halogen atom; m and m' denote an integer of 1-3; R.sub.1 and R.sub.3 independently denote hydrogen atom, C.sub.1-18 alkyl or alkenyl, sufonamide, mesyl, sulfonic acid group, carboxy ester group, hydroxy, C.sub.1-18 alkoxy, acetylamino, benzoylamino or halogen atom; n and n' denote an integer of 1-3; R.sub.2 and R.sub.4 denote hydrogen atom or nitro group; and A.sup.+ denotes hydrogen ion, sodium ion, potassium ion or ammonium ion. The toner has a weight-average particle size (D.sub.4) of 4-9 .mu.m and including toner particles having a particle size of 5 .mu.Type: GrantFiled: March 6, 1995Date of Patent: January 9, 1996Assignee: Canon Kabushiki KaishaInventors: Masaaki Taya, Takaaki Kohtaki, Makoto Unno, Tadashi Doujo
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Patent number: 5480755Abstract: A magnetic toner has magnetic resin particles containing at least a binder resin, a charge control agent and a magnetic powder. The surface-modified fine silica powder being a fine silica powder has been treated with a hydrophobicizing agent. The fine silica powder has a specific surface area of not less than 180 m.sup.2 /g, a hydrophobicity of from 60% to 95% and a bulk density of from 35 g/lit. to 49 g/lit.Type: GrantFiled: August 19, 1994Date of Patent: January 2, 1996Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Yoshinobu Jo, Yasutaka Akashi, Masaaki Taya, Makoto Unno
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Patent number: 5439770Abstract: A toner for developing an electrostatic image is constituted by at least a binder resin and a charge control agent. The binder resin has an acid value of 5-50. The charge control agent comprises an iron complex represented by the following formula: ##STR1## wherein X.sub.1 and X.sub.2 independently denote hydrogen atom, lower alkyl group, lower alkoxy group, nitro group or halogen atom; m and m' denote an integer of 1-3; R.sub.1 and R.sub.3 independently denote hydrogen atom, C.sub.1-18 alkyl or alkenyl, sufonamide, mesyl, sulfonic acid group, carboxy ester group, hydroxy, C.sub.1-18 alkoxy, acetylamino, benzoylamino or halogen atom; n and n' denote an integer of 1-3; R.sub.2 and R.sub.4 denote hydrogen atom or nitro group; and A.sup.+ denotes hydrogen ion, sodium ion, potassium ion or ammonium ion. The toner has a weight-average particle size (D.sub.4) of 4-9 .mu.m and including toner particles having a particle size of 5 .mu.m or smaller at 3-90% by number, toner particles having a particle size of 6.35-10.Type: GrantFiled: April 15, 1994Date of Patent: August 8, 1995Assignee: Canon Kabushiki KaishaInventors: Masaaki Taya, Takaaki Kohtaki, Makoto Unno, Tadashi Doujo
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Patent number: 5422215Abstract: A magnetic toner comprises a binder resin and a magnetic material.The magnetic toner has a volume average particle diameter of not more than 9 .mu.m and the variation coefficient of particle size distribution, (.sigma.T/D).times.100, of the magnetic toner satisfies the following condition:25.ltoreq.(.sigma.T/D).times.100.ltoreq.35where D represents a volume average particle diameter (.mu.m) of the magnetic toner and .sigma.T represents a value of standard deviation of the volume particle size distribution of the magnetic toner,The magnetic material has a number average particle diameter of from 0.1 .mu.m to 0.2 .mu.m and the variation coefficient of particle size distribution, (.sigma./X).times.100, of the magnetic material satisfies the following condition:(.sigma./X).times.100.ltoreq.40where X represents a number average particle diameter (.mu.m) of the magnetic material and .sigma. represents a value of standard deviation of the number particle size distribution of the magnetic material.Type: GrantFiled: January 26, 1994Date of Patent: June 6, 1995Assignee: Canon Kabushiki KaishaInventors: Seiichi Takagi, Makoto Unno
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Patent number: 5348829Abstract: A monocomponent-type developer for developing electrostatic images, includes a magnetic toner containing at least a binder resin and magnetic powder, and 0.5-10 wt. % (based on the magnetic toner) of inorganic fine powder having a length-average particle size of 0.1-5 .mu.m. The developer has a number-basis particle size distribution such that particles of 4 .mu.m or smaller are contained at 5-18% by number and particles of 4-10 .mu.m are contained at at least 60% by number. The developer has a volume basis particle size distribution such that particles of 12.7 .mu.m or larger are contained at at most 10% by volume. The developer has a weight-average particle size of 7-11 .mu.m. The developer is particularly useful for development under application of a DC-superposed asymmetric AC bias electric field including a development-side voltage component with a larger magnitude and a shorter duration than a reverse development-side voltage component.Type: GrantFiled: November 6, 1992Date of Patent: September 20, 1994Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Yasutaka Akashi, Masaaki Taya, Makoto Unno
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Patent number: 5338894Abstract: An image forming method in which a toner-carrying member for carrying a specific magnetic toner is placed adjacent a latent image-bearing member for carrying an electrostatic latent image so as to form a developing region of a predetermined gap size. The magnetic toner on the toner-carrying member forms a toner layer of a regulated thickness smaller than the above-mentioned gap. An asymmetric bias is applied to the magnetic toner so as to cause the magnetic toner from the toner-carrying member to be conveyed to the latent image-bearing member thereby to develop the electrostatic latent image.Type: GrantFiled: September 20, 1991Date of Patent: August 16, 1994Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Hirohide Tanikawa, Yasutaka Akashi, Masaaki Taya, Makoto Unno
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Patent number: 5330871Abstract: A toner for developing an electrostatic image is constituted by a binder resin and a colorant. The binder resin is characterized by containing at least 20 wt. % of an extraction residue after 6 hours of extraction and below 20 wt. % of an extraction residue after 72 hours of extraction respectively by Soxhlet extraction with tetrahydrofuran. The toner shows a dynamic modulus and a loss modulus, respectively at 200.degree. C. and 0.1 Hz, which are substantially unchanging with time. The properties provide the toner with a harmonization of anti-offset characteristic and fixability as well as stable viscoelasticity under heating.Type: GrantFiled: November 26, 1991Date of Patent: July 19, 1994Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Masaki Uchiyama, Yoshinobu Joh, Yasutaka Akashi, Masaaki Taya, Makoto Unno
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Patent number: 5296326Abstract: A magnetic toner for electrophotography having stable triboelectric chargeability under various environmental conditions may be provided by using magnetic iron oxide particles having a moderately high surface Feo content, specified by the following conditions: (a) a dissolved Fe (II) content in dissolved total iron of 14-33.3 wt. % at a dissolved total iron percentage of 5.+-.1 wt. %, (b) a dissolved Fe (II) content in dissolved total iron of 17-33.3 wt. % at a dissolved total iron percentage of 10.+-.1 wt. %, and (c) a dissolved Fe (II) content in dissolved total iron of 18-33.3 wt. % at a dissolved total iron percentage of 15.+-.1 wt.Type: GrantFiled: December 21, 1992Date of Patent: March 22, 1994Assignee: Canon Kabushiki KaishaInventors: Masaaki Taya, Hirohide Tanikawa, Yasutaka Akashi, Makoto Unno, Masaki Uchiyama, Kiichiro Sakashita
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Patent number: 5268248Abstract: A toner for developing an electrostatic image is provided as a pulverized mixture including a binder resin and a colorant. The binder resin is characterized by a molecular weight distribution on a GPC chromatogram of its tetrahydrofuran (THF)-soluble resin content including below 15% of a resin component in a molecular weight region of at most 5000 and at least 5 wt. % of a resin component in a molecular weight region of at least 5.times.10.sup.6 and showing a main peak in a molecular weight region of 5000 to 5.times.10.sup.6. The THF-soluble resin component in the molecular weight region of at least 5.times.10.sup.6 is extremely enriched during a melt-kneading step during the toner production, so as to effectively prevent toner flowout from a member for cleaning a fixing roller.Type: GrantFiled: November 26, 1991Date of Patent: December 7, 1993Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Masaki Uchiyama, Yoshinobu Joh, Yasutaka Akashi, Masaaki Taya, Makoto Unno, Kazuyoshi Hagiwara
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Patent number: 5219946Abstract: A binder resin comprises a vinyl copolymer, a mixture of vinyl copolymers, or a mixture of a vinyl copolymer and a vinyl polymer. A resin component with a molecular weight of not more than 10,000 is contained in an amount of from 5 to 50% by weight based on the whole resin. The vinyl copolymer or the mixture of vinyl copolymers has an acid anhydride group and a carboxyl group.Type: GrantFiled: November 8, 1990Date of Patent: June 15, 1993Inventors: Hirohide Tanikawa, Masaki Uchiyama, Tsutomu Kukimoto, Yasutaka Akashi, Masaaki Taya, Makoto Unno, Seiichi Takagi
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Patent number: 5212524Abstract: A toner for developing electrostatic images, comprises a binder resin and a colorant, wherein the binder resin comprises a vinyl copolymer having an acid anhydride group, and the binder resin has a total acid value (A) of 2-100 mgKOH/g and a total acid value (B) attributable to acid anhydride group of below 6 mgKOH/g so that [(B)/(A)].times.100 is 60% or less. Because the binder resin has a specified acid value partly attributable to acid anhydride group, the toner is provided with an adequate balance between chargeability and dischargeability, so that the toner shows a stable performance under various environmental conditions. The toner is particularly advantageously constituted as a magnetic toner of fine particle sizes suitably used under application of unsymmetrical alternating bias electric field.Type: GrantFiled: August 31, 1992Date of Patent: May 18, 1993Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Yasutaka Akashi, Masaki Uchiyama, Makoto Unno, Masaaki Taya
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Patent number: 5169738Abstract: A toner for developing electrostatic images, comprises a binder resin and a colorant, wherein the binder resin comprises a vinyl copolymer having an acid anhydride group, and the binder resin has a total acid value (A) of 2-100 mgKOH/g and a total acid value (B) attributable to acid anhydride group of below 6 mgKOH/g so that [(B)/(A)].times.100 is 60% or less. Because the binder resin has a specified acid value partly attributable to acid anhydride group, the toner is provided with an adequate balance between chargeability and dischargeability, so that the toner shows a stable performance under various environmental conditions. The toner is particularly advantageously constituted as a magnetic toner of fine particle sizes suitably used under application of unsymmetrical alternating bias electric field.Type: GrantFiled: October 29, 1990Date of Patent: December 8, 1992Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Yasutaka Akashi, Masaki Uchiyama, Makoto Unno, Masaaki Taya