Patents by Inventor Ryuji Ohta
Ryuji Ohta 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: 10571819Abstract: Provided is a yellow toner that has excellent pigment dispersibility, and thus gives a high image density and causes little fog. A yellow toner of the present invention includes at least a binder resin and a yellow pigment, wherein the binder resin is a copolymer that contains 67 to 88% by mass of a styrene-based monomer unit and 12 to 33% by mass of a alkyl (meth)acrylate monomer unit, wherein a content of the yellow pigment is 3 to 15 parts by mass with respect to 100 parts by mass of the binder resin; and wherein a interfacial tension of a mixed solution of 9 parts by mass of the yellow pigment, 72 parts by mass of styrene and 28 parts by mass of n-butyl acrylate with respect to water, is 5 to 19 mN/m.Type: GrantFiled: April 30, 2018Date of Patent: February 25, 2020Assignee: ZEON CORPORATIONInventor: Ryuji Ohta
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Patent number: 10503089Abstract: There is provided a toner for developing electrostatic images, including an external additive and colored resin particles containing a binder resin, a colorant and softening agents. The colored resin particles contain a monoester compound A represented by formula (1) and a monoester compound B represented by formula (2) as softening agents. A content of the monoester compound A is in the range from 95 to 99% by mass, a content of the monoester compound B is in the range from 1 to 5% by mass, and a content of the softening agents is in the range from 10 to 30 parts by mass, with respect to 100 parts by mass of the binder resin. Formula (1) is R1—COO—R2. Formula (2) is R3—COO—R4.Type: GrantFiled: March 26, 2014Date of Patent: December 10, 2019Assignees: ZEON CORPORATION, NOF CORPORATIONInventors: Azusa Masuda, Ryuji Ohta, Munehiro Yamada, Norifumi Itako, Ryosuke Uemura
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Patent number: 10372054Abstract: Provided is a toner that is excellent in heat-resistant shelf stability and low-temperature fixability, has durability, and causes less occurrence of fogging in high temperature and high humidity environments. The toner comprising at least a binder resin, a colorant, a release agent, a retention aid and a charge control resin. The binder resin is a copolymer containing a styrene-based monomer unit 67 to 78% by mass and a (meth)acrylic acid alkyl monomer unit 22 to 33% by mass. The content of the retention aid is 1 to 4 parts by mass with respect to 100 parts by mass of the binder resin, and the content of the charge control resin is 0.1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.Type: GrantFiled: January 12, 2018Date of Patent: August 6, 2019Assignee: ZEON CORPORATIONInventor: Ryuji Ohta
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Publication number: 20180246433Abstract: Provided is a yellow toner that has excellent pigment dispersibility, and thus gives a high image density and causes little fog. A yellow toner of the present invention includes at least a binder resin and a yellow pigment, wherein the binder resin is a copolymer that contains 67 to 88% by mass of a styrene-based monomer unit and 12 to 33% by mass of a alkyl (meth)acrylate monomer unit, wherein a content of the yellow pigment is 3 to 15 parts by mass with respect to 100 parts by mass of the binder resin; and wherein a interfacial tension of a mixed solution of 9 parts by mass of the yellow pigment, 72 parts by mass of styrene and 28 parts by mass of n-butyl acrylate with respect to water, is 5 to 19 mN/m.Type: ApplicationFiled: April 30, 2018Publication date: August 30, 2018Applicant: ZEON CORPORATIONInventor: Ryuji Ohta
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Publication number: 20180136574Abstract: Provided is a toner that is excellent in heat-resistant shelf stability and low-temperature fixability, has durability, and causes less occurrence of fogging in high temperature and high humidity environments. The toner comprising at least a binder resin, a colorant, a release agent, a retention aid and a charge control resin. The binder resin is a copolymer containing a styrene-based monomer unit 67 to 78% by mass and a (meth)acrylic acid alkyl monomer unit 22 to 33% by mass. The content of the retention aid is 1 to 4 parts by mass with respect to 100 parts by mass of the binder resin, and the content of the charge control resin is 0.1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.Type: ApplicationFiled: January 12, 2018Publication date: May 17, 2018Applicant: ZEON CORPORATIONInventor: Ryuji Ohta
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Patent number: 9904192Abstract: Provided is a toner that is excellent in heat-resistant shelf stability and low-temperature fixability, has durability, and causes less occurrence of fogging in high temperature and high humidity environments. The toner comprising at least a binder resin, a colorant, a release agent, a retention aid and a charge control resin. The binder resin is a copolymer containing a styrene-based monomer unit 67 to 78% by mass and a (meth)acrylic acid alkyl monomer unit 22 to 33% by mass. The content of the retention aid is 1 to 4 parts by mass with respect to 100 parts by mass of the binder resin, and the content of the charge control resin is 0.1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.Type: GrantFiled: February 9, 2016Date of Patent: February 27, 2018Assignee: ZEON CORPORATIONInventor: Ryuji Ohta
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Publication number: 20170168408Abstract: Provided is a yellow toner that has excellent pigment dispersibility, and thus gives a high image density and causes little fog. A yellow toner of the present invention includes at least a binder resin and a yellow pigment, wherein the binder resin is a copolymer that contains 67 to 88% by mass of a styrene-based monomer unit and 12 to 33% by mass of a alkyl (meth)acrylate monomer unit, wherein a content of the yellow pigment is 3 to 15 parts by mass with respect to 100 parts by mass of the binder resin; and wherein a interfacial tension of a mixed solution of 9 parts by mass of the yellow pigment, 72 parts by mass of styrene and 28 parts by mass of n-butyl acrylate with respect to water, is 5 to 19 mN/m.Type: ApplicationFiled: February 17, 2015Publication date: June 15, 2017Applicant: ZEON CORPORATIONInventor: Ryuji Ohta
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Patent number: 9557668Abstract: The present invention is to provide a toner which has an excellent balance between heat-resistant storage stability and low-temperature fixability and which is excellent in printing durability even under a wide range of temperature and humidity environments from a low temperature and low humidity environment to a high temperature and high humidity environment. Disclosed is a toner for developing electrostatic images, containing colored resin particles containing a binder resin, a colorant, a softening agent and a retention aid, and an external additive, wherein the retention aid is a copolymer of at least one of acrylic acid ester and methacrylic acid ester and at least one of acrylic acid and methacrylic acid, and wherein the copolymer has an acid value of 0.5 to 7 mgKOH/g, a weight average molecular weight Mw of 6,000 to 50,000, and a glass transition temperature of 60 to 85° C.Type: GrantFiled: February 26, 2014Date of Patent: January 31, 2017Assignee: ZEON CORPORATIONInventors: Azusa Masuda, Ryuji Ohta
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Publication number: 20160246196Abstract: Provided is a toner that is excellent in heat-resistant shelf stability and low-temperature fixability, has durability, and causes less occurrence of fogging in high temperature and high humidity environments. The toner comprising at least a binder resin, a colorant, a release agent, a retention aid and a charge control resin. The binder resin is a copolymer containing a styrene-based monomer unit 67 to 78% by mass and a (meth)acrylic acid alkyl monomer unit 22 to 33% by mass. The content of the retention aid is 1 to 4 parts by mass with respect to 100 parts by mass of the binder resin, and the content of the charge control resin is 0.1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.Type: ApplicationFiled: February 9, 2016Publication date: August 25, 2016Applicant: ZEON CORPORATIONInventor: Ryuji Ohta
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Publication number: 20160048090Abstract: There is provided a toner for developing electrostatic images, including an external additive and colored resin particles containing a binder resin, a colorant and softening agents. The colored resin particles contain a monoester compound A represented by formula (1) and a monoester compound B represented by formula (2) as softening agents. A content of the monoester compound A is in the range from 95 to 99% by mass, a content of the monoester compound B is in the range from 1 to 5% by mass, and a content of the softening agents is in the range from 10 to 30 parts by mass, with respect to 100 parts by mass of the binder resin. Formula (1) is R1—COO—R2. Formula (2) is R3—COO—R4.Type: ApplicationFiled: March 26, 2014Publication date: February 18, 2016Applicants: ZEON CORPORATION, NOF CORPORATIONInventors: Azusa Masuda, Ryuji Ohta, Munehiro Yamada, Norifumi Itako, Ryosuke Uemura
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Publication number: 20160004176Abstract: The present invention is to provide a toner which has an excellent balance between heat-resistant storage stability and low-temperature fixability and which is excellent in printing durability even under a wide range of temperature and humidity environments from a low temperature and low humidity environment to a high temperature and high humidity environment. Disclosed is a toner for developing electrostatic images, containing colored resin particles containing a binder resin, a colorant, a softening agent and a retention aid, and an external additive, wherein the retention aid is a copolymer of at least one of acrylic acid ester and methacrylic acid ester and at least one of acrylic acid and methacrylic acid, and wherein the copolymer has an acid value of 0.5 to 7 mgKOH/g, a weight average molecular weight Mw of 6,000 to 50,000, and a glass transition temperature of 60 to 85° C.Type: ApplicationFiled: February 26, 2014Publication date: January 7, 2016Applicant: ZEON CORPORATIONInventors: Azusa Masuda, Ryuji Ohta
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Patent number: 4846047Abstract: A brake booster is disclosed which reduces an idle stroke of an input shaft, by bringing a key member which is mechanically coupled to a valve plunger into abutment against an inner wall surface of a shell when the brake booster is inoperative. The shell includes a cylindrical projection which extends rearwardly from the center thereof, and the cylindrical projection is formed with a flange which extends radially inward, with its inner periphery cut away to define an opening. A valve body includes a cylindrical portion which extends through the opening to the outside thereof. By disposing the key member for abutment against the inner wall surface of the flange, a reduction in the length of the key member is enabled. A seal member seals the cylindrical portion of the valve body, and is located rearwardly of the flange and is received within a housing which is disposed outside the shell.Type: GrantFiled: February 2, 1988Date of Patent: July 11, 1989Assignee: Jidosha Kiki Co., Ltd.Inventors: Shintaro Uyama, Ryuji Ohta, Yoshimichi Inoue
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Patent number: 4807521Abstract: A casing for use in a brake booster or clutch booster is provided. The casing includes a cylindrical portion which defines an outer periphery thereof, a flat central end wall which is disposed substantially perpendicular to the axis of the cylindrical portion, and a frustoconical portion which interconnects the cylindrical portion and the central end wall. According to the invention, a flat peripheral end wall is disposed between the cylindrical portion and the frustoconical portion so as to be substantially perpendicular to the axis of the cylindrical portion, thus increasing the rigidity of the casing.Type: GrantFiled: November 25, 1987Date of Patent: February 28, 1989Assignee: Jidosha Kiki Co., Ltd.Inventors: Shintaro Uyama, Ryuji Ohta
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Patent number: 4623044Abstract: A brake apparatus has an actuator mechanism for bringing a friction member into tight contact with a braking member so as to obtain a braking force, the actuator mechanism including: a moving piezoceramic member which can be elongated/contracted along a direction in which the friction member is urged; a holder disposed between opposing ends of the friction member and the moving piezoceramic member to couple the friction member and the moving piezoceramic member; and members for selectively restraining movement of the moving piezoceramic element in a direction parallel to the direction in which it is urged with respect to a fixing member.Type: GrantFiled: December 14, 1984Date of Patent: November 18, 1986Assignee: Jidosha Kiki Co., Ltd.Inventors: Ryuji Ohta, Michio Kobayashi
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Patent number: 4602702Abstract: A brake apparatus has an actuator mechanism for bringing a friction member into tight contact with a braking member to generate a braking force, the actuator mechanism comprising:a main actuating unit for moving the friction member to a position where the friction member is in contact with the braking member;a subactuating unit for further urging the friction member which is in contact with the braking member so as to generate the braking force, the subactuating unit being constituted by a piezoceramic element; anda controller for operating the main actuating unit first and then the subactuating unit in accordance with a brake command from a first sensor.Type: GrantFiled: December 18, 1984Date of Patent: July 29, 1986Assignee: Jidosha Kiki Co., Ltd.Inventors: Ryuji Ohta, Michio Kobayashi
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Patent number: 4437390Abstract: A power-servo booster having a shortened overall length and lighter weight. A fitting member disposed within a connection hole in a power piston is cylindrically formed and a reaction disk is disposed within the cylindrical fitting member. An annular groove is formed in an outer periphery at the bottom of the connection hole and the power piston. A portion of the power piston within the annular groove projects towards the push rod and the reaction disk disposed within the fitting member is placed within the connection hole so that it can contact with an end surface of the projecting portion. The peripheral end of the fitting member is adapted to fit within the annular groove. An annular gap is formed between the fitting member and the bottom of the annular groove to allow for deformation of the reaction disk.Type: GrantFiled: June 2, 1981Date of Patent: March 20, 1984Assignee: Jidosha Kiki Co., Ltd.Inventor: Ryuji Ohta
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Patent number: 4296680Abstract: A vacuum power servo booster including a disc-shaped inner shell and a cup-shaped outer shell with a diaphragm secured between the two shells. A radially opening annular groove is formed in peripheral portions of the inner shell by a first annularly bent portion bulging radially inwardly and a second annularly bent portion oriented along the axial direction of the booster. The outer shell includes rectangular recesses into which extend inwardly at the open faces.Type: GrantFiled: October 17, 1979Date of Patent: October 27, 1981Assignee: Jidosha Kiki Co., Ltd.Inventors: Ryuji Ohta, Michio Kobayashi
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Patent number: 4292887Abstract: A power servo of the fluid differential type having a power piston and a diaphragm defining two cavities maintained at a differential pressure. An air passage is formed to release any air present in a space between the diaphragm and the disc portion of the power piston. The air passage may be formed as a split groove in the flange or as a hole through it. The groove may be either circumferential or axial to allow air to escape into the atmospheric chamber of the power servo.Type: GrantFiled: October 26, 1978Date of Patent: October 6, 1981Assignee: Jidosha Kiki Co., Ltd.Inventors: Ryuji Ohta, Yoshimichi Inoue
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Patent number: RE31911Abstract: A vacuum power servo booster including a disc-shaped inner shell and a cup-shaped outer shell with a diaphragm secured between the two shells. A radially opening annular groove is formed in peripheral portions of the inner shell by a first annularly bent portion bulging radially inwardly and a second annularly bent portion oriented along the axial direction of the booster. The outer shell includes rectangular recesses into which extend inwardly at the open faces.Type: GrantFiled: October 27, 1983Date of Patent: June 11, 1985Assignee: Jidosha Kiki Co., Ltd.Inventors: Ryuji Ohta, Michio Kobayashi