Patents by Inventor Kenji Tamamitsu

Kenji Tamamitsu 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).

  • Patent number: 8837114
    Abstract: A solid electrolytic capacitor is impregnated with a conductive polymer dispersion solution comprising sorbitol. In the capacitor, the hydroxyl group of sorbitol acts as the oxygen source necessary for the anodic oxidation of anodic oxide film when voltage is applied to the solid electrolytic capacitor. Consequently, the oxide film is repaired and withstand voltage property is improved, which is thought to be due to the anodic oxidation that repairs the damage on the oxide film. Superior electric capacitance can further be attained by specifying the sorbitol content in the dispersion solution to be at 60-90 wt %.
    Type: Grant
    Filed: March 29, 2011
    Date of Patent: September 16, 2014
    Inventors: Nozomu Kamiyama, Kenji Machida, Atsushi Yoshizawa, Sekihiro Takeda, Kenji Tamamitsu
  • Patent number: 8824120
    Abstract: An electrical double-layer capacitor electrode with excellent capacitance characteristics is obtained together with a manufacturing method therefor. Paper-molded sheet of carbon nanotubes is integrated with etched foil constituting a collector, by means of bumps and indentations formed on the surface of etched foil to prepare an electrical double-layer capacitor electrode. Alternatively, carbon nanotubes grown around core catalyst particles on substrate are integrated with etched foil by means of bumps and indentations formed on the surface of etched foil to prepare an electrical double-layer capacitor electrode. To manufacture these electrodes, this carbon nanotube sheet or substrate with carbon nanotubes grown thereon is laid over bumps and indentations on the surface of etched foil, and the sheet or substrate and the foil are pressed under 0.01 to 100 t/cm2 of pressure to integrate the carbon nanotubes with the etched foil.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: September 2, 2014
    Assignee: Nippon Chemi-con Corporation
    Inventors: Kenji Machida, Shunzo Suemastu, Kenji Tamamitsu
  • Publication number: 20140133066
    Abstract: Disclosed are an aluminum electrolytic capacitor having low impedance properties and a long service life, and an electrolytic solution which enables to give such capacitor. The electrolytic solution contains a solvent containing water, a phosphorus oxoacid ion-generating compound which can generate a phosphorus oxoacid ion in an aqueous solution, and a chelating agent which can coordinate with aluminum to form an aqueous aluminum chelate complex. The electrolytic solution further contains a compound selected from the group consisting of azelaic acid and an azelaic acid salt, and a compound selected from the group consisting of formic acid, a formic acid salt, adipic acid, an adipic acid salt, glutaric acid and a glutaric acid salt. The content of azelaic acid and/or the azelaic acid salt is at least 0.03 moles per kg of the solvent.
    Type: Application
    Filed: January 28, 2014
    Publication date: May 15, 2014
    Applicant: NIPPON CHEMI-CON CORPORATION
    Inventors: Masao SAKAKURA, Junichi KAWAKAMI, Kazuma OKURA, Shingo TAKEUCHI, Masashi OZAWA, Kenji TAMAMITSU
  • Patent number: 8675347
    Abstract: Disclosed are an aluminum electrolytic capacitor having low impedance properties and a long service life, and an electrolytic solution which enables to give such capacitor. The electrolytic solution contains a solvent containing water, a phosphorus oxoacid ion-generating compound which can generate a phosphorus oxoacid ion in an aqueous solution, and a chelating agent which can coordinate with aluminum to form an aqueous aluminum chelate complex. The electrolytic solution further contains a compound selected from the group consisting of azelaic acid and an azelaic acid salt, and a compound selected from the group consisting of formic acid, a formic acid salt, adipic acid, an adipic acid salt, glutaric acid and a glutaric acid salt. The content of azelaic acid and/or the azelaic acid salt is at least 0.03 moles per kg of the solvent.
    Type: Grant
    Filed: July 11, 2009
    Date of Patent: March 18, 2014
    Assignee: Nippon Chemi-Con Corporation
    Inventors: Masao Sakakura, Junichi Kawakami, Kazuma Okura, Shingo Takeuchi, Masashi Ozawa, Kenji Tamamitsu
  • Publication number: 20130115516
    Abstract: Highly dispersed lithium titanate crystal structures having a thickness of few atomic layers level and the two-dimensional surface in a plate form are supported on carbon nanofiber (CNF). The lithium titanate crystal structure precursors and CNF that supports these are prepared by a mechanochemical reaction that applies sheer stress and centrifugal force to a reactant in a rotating reactor. The mass ratio between the lithium titanate crystal structure and carbon nanofiber is preferably between 75:25 and 85:15. The carbon nanofiber preferably has an external diameter of 10-30 nm and an external specific surface area of 150-350 cm2/g. This composite is mixed with a binder and then molded to obtain an electrode, and this electrode is employed for an electrochemical element.
    Type: Application
    Filed: May 2, 2011
    Publication date: May 9, 2013
    Inventors: Katsuhiko Naoi, Wako Naoi, Shuichi Ishimoto, Kenji Tamamitsu
  • Patent number: 8427811
    Abstract: An electrical double-layer capacitor electrode with excellent capacitance characteristics is obtained together with a manufacturing method therefor. Paper-molded sheet 2 of carbon nanotubes is integrated with etched foil 1 constituting a collector, by means of bumps and indentations 1a formed on the surface of etched foil 1 to prepare an electrical double-layer capacitor electrode. Alternatively, carbon nanotubes 4 grown around core catalyst particles on substrate 3 are integrated with etched foil 1 by means of bumps and indentations 1a formed on the surface of etched foil 1 to prepare an electrical double-layer capacitor electrode. To manufacture these electrodes, this carbon nanotube sheet 2 or substrate 3 with carbon nanotubes grown thereon is laid over bumps and indentations 1a on the surface of etched foil 1, and the sheet or substrate and the foil are pressed under 0.01 to 100 t/cm2 of pressure to integrate the carbon nanotubes with the etched foil.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: April 23, 2013
    Assignee: Nippon Chemi-Con Corporation
    Inventors: Kenji Machida, Shunzo Suematsu, Kenji Tamamitsu
  • Publication number: 20130095384
    Abstract: A composite powder in which highly dispersed metal oxide nanoparticle precursors are supported on carbon is rapidly heated under nitrogen atmosphere, crystallization of metal oxide is allowed to progress, and highly dispersed metal oxide nanoparticles are supported by carbon. The metal oxide nanoparticle precursors and carbon nanoparticles supporting said precursors are prepared by a mechanochemical reaction that applies sheer stress and centrifugal force to a reactant in a rotating reactor. The rapid heating treatment in said nitrogen atmosphere is desirably heating to 400° C.-1000° C. By further crushing the heated composite, its aggregation is eliminated and the dispersity of metal oxide nanoparticles is made more uniform. Examples of a metal oxide that can be used are manganese oxide, lithium iron phosphate, and lithium titanate. Carbons that can be used are carbon nanofiber and Ketjen Black.
    Type: Application
    Filed: March 31, 2011
    Publication date: April 18, 2013
    Inventors: Katsuhiko Naoi, Wako Naoi, Shuichi Ishimoto, Kenji Tamamitsu
  • Publication number: 20130070393
    Abstract: A solid electrolytic capacitor is impregnated with a conductive polymer dispersion solution comprising sorbitol. In the capacitor, the hydroxyl group of sorbitol acts as the oxygen source necessary for the anodic oxidation of anodic oxide film when voltage is applied to the solid electrolytic capacitor. Consequently, the oxide film is repaired and withstand voltage property is improved, which is thought to be due to the anodic oxidation that repairs the damage on the oxide film. Superior electric capacitance can further be attained by specifying the sorbitol content in the dispersion solution to be at 60-90 wt %.
    Type: Application
    Filed: March 29, 2011
    Publication date: March 21, 2013
    Inventors: Nozomu Kamiyama, Kenji Machida, Atsushi Yoshizawa, Sekihiro Takeda, Kenji Tamamitsu
  • Publication number: 20130063867
    Abstract: A mixed solvent is prepared by dissolving acetic acid and lithium acetate in a mixture of isopropanol and water. This mixed solvent together with titanium alkoxide and carbon nanofiber (CNF) were introduced into a rotary reactor, the inner tube was rotated at a centrifugal force of 66,000 N (kgms?2) for 5 minutes to form a thin film of the reactant on the inner wall of the outer tube, and sheer stress and centrifugal force were applied to the reactant to allow promotion of chemical reaction, yielding CNF on which highly dispersed lithium titanate nanoparticle precursors are supported. The obtained composite powder was heated under nitrogen atmosphere at 900° C. for 3 minutes, yielding a composite powder in which highly dispersed lithium titanate nanoparticles are supported on CNF, wherein crystallization of lithium titanate was allowed to progress.
    Type: Application
    Filed: March 31, 2011
    Publication date: March 14, 2013
    Inventors: Katsuhiko Naoi, Wako Naoi, Shuichi Ishimoto, Kenji Tamamitsu
  • Publication number: 20120183860
    Abstract: Disclosed is a negative electrode active material which has a high capacity and good cyclability. The negative electrode active material comprises nanosize carbon particles and nanosize tin dioxide particles that are supported in a high-dispersion state on the nanosize carbon particles. The negative electrode active material has a high discharge capacity because of the reversible progress of a conversion reaction of tin dioxide (SnO2+4Li++4e??2Li2O+Sn) therein. In a charge-discharge cycle test within a voltage range of 0 to 2 V vs. an Li/Li+ electrode, the negative electrode active material shows a discharge capacity retention rate of about 90% even after 500 charge-discharge cycles at the rate 1 C, which indicates excellent cyclability. Therefore, the negative electrode active material can be suitably used in a lithium ion secondary battery and a hybrid capacitor.
    Type: Application
    Filed: September 29, 2010
    Publication date: July 19, 2012
    Inventors: Katsuhiko Naoi, Wako Naoi, Shuichi Ishimoto, Kenji Tamamitsu
  • Publication number: 20120132861
    Abstract: The electrode material includes metal oxide nanoparticles formed by applying shear force and centrifugal force to reactants containing a reaction inhibitor in a rotating reaction vessel during a chemical reaction; and carbon nanotubes with a specific area of 600 to 2600 m2/g to which shear force and centrifugal force are applied for dispersion in the rotating reaction vessel during the chemical reaction. The metal oxide particles are highly dispersed and carried on the carbon nanotubes. Preferably, the metal oxide is lithium titanate.
    Type: Application
    Filed: March 8, 2010
    Publication date: May 31, 2012
    Inventors: Kenji Tamamitsu, Shuichi Ishimoto, Katsuhiko Naoi, Wako Naoi, Hiroako Hatori, Kenji Hata, Motoo Yumura
  • Publication number: 20120026645
    Abstract: Disclosed are an aluminum electrolytic capacitor having low impedance properties and a long service life, and an electrolytic solution which enables to give such capacitor. The electrolytic solution contains a solvent containing water, a phosphorus oxoacid ion-generating compound which can generate a phosphorus oxoacid ion in an aqueous solution, and a chelating agent which can coordinate with aluminum to form an aqueous aluminum chelate complex. The electrolytic solution further contains a compound selected from the group consisting of azelaic acid and an azelaic acid salt, and a compound selected from the group consisting of formic acid, a formic acid salt, adipic acid, an adipic acid salt, glutaric acid and a glutaric acid salt. The content of azelaic acid and/or the azelaic acid salt is at least 0.03 moles per kg of the solvent.
    Type: Application
    Filed: July 11, 2009
    Publication date: February 2, 2012
    Inventors: Masao Sakakura, Junichi Kawakami, Kazuma Okura, Shingo Takeuchi, Masashi Ozama, Kenji Tamamitsu
  • Publication number: 20100259867
    Abstract: An electrical double-layer capacitor electrode with excellent capacitance characteristics is obtained together with a manufacturing method therefor. Paper-molded sheet 2 of carbon nanotubes is integrated with etched foil 1 constituting a collector, by means of bumps and indentations 1a formed on the surface of etched foil 1 to prepare an electrical double-layer capacitor electrode. Alternatively, carbon nanotubes 4 grown around core catalyst particles on substrate 3 are integrated with etched foil 1 by means of bumps and indentations 1a formed on the surface of etched foil 1 to prepare an electrical double-layer capacitor electrode. To manufacture these electrodes, this carbon nanotube sheet 2 or substrate 3 with carbon nanotubes grown thereon is laid over bumps and indentations la on the surface of etched foil 1, and the sheet or substrate and the foil are pressed under 0.01 to 100 t/cm2 of pressure to integrate the carbon nanotubes with the etched foil.
    Type: Application
    Filed: September 29, 2008
    Publication date: October 14, 2010
    Inventors: Kenji Machida, Shunzo Suematsu, Kenji Tamamitsu
  • Publication number: 20090026085
    Abstract: A method for producing an electrode for an electrochemical element absorbs monomers for polymerization on a surface having a specific surface area of 100 to 3000 m2g?1 and having an average pore diameter in the range of 0.4 to 100 nm, performing electrolysis polymerization by applying pulse voltage, and forming a conductive polymer layer on the surface of the conductive porous material, forming a thin and uniform electrode film. In a method for producing an electrochemical element, a conductive polymer layer is formed on the conductive porous material by absorbing monomers for polymerization on a surface of a conductive porous material having a specific surface area and pore diameter as above forming a electrochemical cell by using the conductive porous material, the monomers are absorbed in the pores, putting the electrochemical cell and the electrolyte solution in an outer casing, and performing electrolysis polymerization of the monomers in the electrolyte solution.
    Type: Application
    Filed: June 10, 2005
    Publication date: January 29, 2009
    Applicants: NIPPON CHEMI-CON CORPORATION, GEN3 PARTNERS, INC.
    Inventors: Hidenori Uchi, Kenji Tamamitsu, Shunzo Suematsu, Satoru Tsumeda, Alexander M. Timonov, Sergey A. Logvinov, Nikolay Shkolnik, Sam Kogan
  • Publication number: 20080300381
    Abstract: To provide an electrode material excellent in output characteristics and cycle property and an electrochemical device using the electrode material. The electrode material comprising polymer complex compound represented by the following graphical formula: and the electrochemical device using the electrode material. Even if such a large size ion is employed, enhanced output characteristics could be obtained in the present invention. Polymer complex compound is polarized due to an electron attracting substituent, or steric hindrance occurs due to a substituent having a branch structure so that interval of polymer complex compound formed on the electrode is increased and doping reaction. Therefore, even if using large size ions smooth and rapid doping and undoping reaction could take place.
    Type: Application
    Filed: September 30, 2004
    Publication date: December 4, 2008
    Applicant: NIPPON CHEMI-CON CORPORATION
    Inventors: Hidenori Uchi, Kenji Tamamitsu, Shunzo Suematsu, Satoru Tsumeda, Alexander M. Timonov, Sergey A. Logvinov, Nikolay Shkolnik, Sam Kogan
  • Publication number: 20080213500
    Abstract: To provide a method for producing an electrode material which is improved in energy density and is excellent in output characteristics. The present invention provides a manufacturing method for the electrode material comprising the steps of: 1) immersing a conductive material having a specific surface area of 200 to 3000 m2g?1 in a complex monomer solution of a transition metal having at least two different oxidation numbers, 2) performing electro polymerization by applying pulse voltage using the conductive material as an electrode to stack the complex monomer under the condition that electrolyzation time is 0.
    Type: Application
    Filed: September 30, 2004
    Publication date: September 4, 2008
    Applicants: NIPPON CHEMI-CON CORPORATION, GEN3PARTNER, INC.
    Inventors: Hidenori Uchi, Kenji Tamamitsu, Satori Tsumeda, Alexander M. Timonov, Sergey Nikolay Shkolnik, Sam Kogan
  • Patent number: 6493211
    Abstract: An electrolyte having a high conductivity, an excellent high-temperature life characteristic and leading to improvement of the shelf characteristic of an aluminum electrolytic capacitor. At least one phosphate ion producing compound and a chelating agent are added using a solvent largely composed of water. Therefor, an aluminum electrolytic capacitor comprising such an electrolyte has a low impedance, an excellent high-temperature life characteristic, and an improved shelf characteristic.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: December 10, 2002
    Assignee: Nippon Chemi-Con Corporation
    Inventors: Takayuki Sugiyama, Masashi Ozawa, Hidehiko Itoh, Kenji Tamamitsu, Masao Sakakura
  • Patent number: 6274061
    Abstract: The present invention provides an electrolytic capacitor having excellent high temperature life characteristics and excellent low temperature properties, an aluminum electrolytic capacitor having excellent high temperature life characteristics and moisture resistance, a low dielectric loss and good low temperature properties, and an electrolyte therefor. A first electrolyte comprises a mixed solvent of sulfolane and at least one selected from 3-methyl sulfolane and 2,4-dimethyl sulfolane, a second electrolyte in which a quaternized imidazolinium salt or a quaternized pyrimidinium salt is dissolved in a mixed solvent containing sulfolane and &ggr;-butyrolactone, and a third electrolyte comprises a mixed solvent containing &ggr;-butyrolactone and at least two selected from sulfolane, 3-methyl sulfolane and 2,4-dimethyl sulfolane and a quaternized imidazolinium salt or a quaternized pyrimidinium.
    Type: Grant
    Filed: August 17, 2000
    Date of Patent: August 14, 2001
    Assignee: Nippon Chemi-Con Corporation
    Inventor: Kenji Tamamitsu
  • Patent number: 6166899
    Abstract: And electrolytic capacitor having excellent high temperature life characteristics and excellent low temperature properties, an aluminum electrolytic capacitor having excellent high temperature life characteristics and moisture resistance, a low dielectric loss and good low temperature properties, and an electrolyte therefor. A first electrolyte which includes a mixed solvent of sulfolane and at least one 3-methyl sulfolane and 2,4-dimethyl sulfolane, a second electrolyte in which a quaternized imidazolinium salt or a quaternized pyrimidinium salt is dissolved in a mixed solvent containing sulfolane and .gamma.-butyrolactone, and a third electrolyte which includes a mixed solvent containing .gamma.-butyrolactone and at least two of sulfolane, 3-methyl sulfolane and 2,4-dimethyl sulfolane and a quaternized imidazolinium salt or a quaternized pyrimidinium.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: December 26, 2000
    Assignee: Nippon Chemi-Con Corporation
    Inventor: Kenji Tamamitsu