Patents by Inventor Takayuki Nakakawaji

Takayuki Nakakawaji 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: 10155916
    Abstract: Provided is a lubricant for a gas insulated switchgear, with which properties of a base oil such as heat resistance, evaporation loss, fluidity under a low temperature, and chemical stability (oxidation resistance and HF resistance) are balanced at a level higher than the conventional level, and long service life and high reliability of the gas insulated switchgear are achieved. A lubricant for a gas insulated switchgear according to the present invention, contains: a base oil containing a polyalphaolefin having a kinematic viscosity at 40° C. of 50 mm2/s or more; and a thickener containing bisamides.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: December 18, 2018
    Assignee: HITACHI, LTD.
    Inventors: Takayuki Nakakawaji, Hiroyuki Akata, Tomohiro Moriyama, Kazuhiro Satou, Makoto Hirose
  • Publication number: 20170349854
    Abstract: Provided is a lubricant for a gas insulated switchgear, with which properties of a base oil such as heat resistance, evaporation loss, fluidity under a low temperature, and chemical stability (oxidation resistance and HF resistance) are balanced at a level higher than the conventional level, and long service life and high reliability of the gas insulated switchgear are achieved. A lubricant for a gas insulated switchgear according to the present invention, contains: a base oil containing a polyalphaolefin having a kinematic viscosity at 40° C. of 50 mm2/s or more; and a thickener containing bisamides.
    Type: Application
    Filed: February 4, 2016
    Publication date: December 7, 2017
    Applicant: HITACHI, LTD.
    Inventors: Takayuki NAKAKAWAJI, Hiroyuki AKATA, Tomohiro MORIYAMA, Kazuhiro SATOU, Makoto HIROSE
  • Patent number: 7820114
    Abstract: A highly reliable reaction container capable of restraining an initial detection failure (bubble attachment), and a biochemical and/or immunological automatic analyzer loaded with the reaction container. In a reaction container made of a synthetic resin and used for receiving a biological sample and a reagent, developing a biochemical and/or immunological reaction between the biological sample and the reagent, and measuring proceedings of the reaction and/or the state at a predetermined point in time by optical means, an inner wall surface of the reaction container in contact with the biological sample, the reagent, and a reaction product of the biological sample and the reagent has a critical surface tension of not smaller than 25.0 mN/m, or a contact angle between the inner wall surface of the reaction container and a solvent of a reaction solution is not larger than 60 degrees.
    Type: Grant
    Filed: August 27, 2004
    Date of Patent: October 26, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Mina Amo, Takayuki Nakakawaji, Taku Sakazume, Katsuhiro Kambara
  • Publication number: 20100195240
    Abstract: A thermally assisted magnetic recording disk drive, comprises: a magnetic recording medium, on a surface of non-magnetic substrate of which are formed an under layer, a vertical magnetic recording layer, a protective layer and a lubricant layer, sequentially; a recording/reproducing head having a magnetic pole, which is configured to apply a magnetic field onto the magnetic recording medium, and a heating means, which is configured to heat an area being applied with a magnetic field by means of a near-field light; a mechanism, which is configured to rotate the magnetic recording medium; a mechanism, which is configured to position the recording/reproducing head; and a circuit, which is configured to process a recording/reproducing signal, and further comprising, a plate-like structure, which supplies a lubricant onto a surface of the magnetic recording medium and thereby having a function of cooling the surface of the magnetic recording medium.
    Type: Application
    Filed: January 29, 2010
    Publication date: August 5, 2010
    Inventors: Takayuki Nakakawaji, Mina Amo
  • Publication number: 20070270085
    Abstract: To provide a slurry for Chemical Mechanical Polishing, a Chemical Mechanical Polishing method using said slurry, and a method of producing electronic devices using said method that makes it possible to achieve a low scratch process capability in processing surfaces such as SiO2 film surfaces and the like and also to enable speed polishing to attain a high processing efficiency. Slurry for Chemical Mechanical Polishing characterized in comprising abrasive grains and water, wherein said abrasive grains are composite particles coated with ceria particles consisting of organic host particles and ceria particles, zeta potential of said composite particles being a negative potential, the organic host particles constituting the composite particles coated with ceria particles are organic host particles to which carboxyl groups and sulfonyl groups are introduced; the slurry is added with panarization additive; and the planarization additive is poly(methyl)acrylic acid ammonium salt.
    Type: Application
    Filed: February 27, 2007
    Publication date: November 22, 2007
    Inventors: Ryo Ota, Takayuki Nakakawaji, Toranosuke Ashizawa, Naoyuki Koyama
  • Patent number: 6917495
    Abstract: A magnetic disk drive having a magnetic disk, a spindle motor for rotating the magnetic disk, a magnetic head slider for recording or reproducing data onto or from the magnetic disk and a housing. A control circuit system is provided for controlling the head slider so that the head slider is positioned on the magnetic disk plane when the magnetic disk is rotating, and the head slider is saved to outside the magnetic disk plane when rotation of the magnetic disk is stopped. A lubricant supplier is provided for supplying lubricant to the surface of the magnetic disk. The lubricant supplier contains at least a perfluoropolyether compound having any one of an alcohol group, a cyclic ether group, and an alkyl-ester group at its terminal position as a lubricant, and the lubricant contains the perfluoropolyether compound having a molecular weight sufficient to enable lubrication and no greater than 4000.
    Type: Grant
    Filed: October 22, 2003
    Date of Patent: July 12, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Takayuki Nakakawaji, Mina Ishida, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani
  • Publication number: 20050095461
    Abstract: A magnetic disk to which is applied a first lubricating agent formed as (where p=0 or an integer of at least 1, q=0 or an integer of at least 1, and X=1-5), and over which is applied a second lubricating agent formed as HOCH2CF2(OC2F4)p(OCF2)qOCF2CH2OH (where p=0 or an integer of at least 1, q=0 or an integer of at least 1.
    Type: Application
    Filed: November 4, 2004
    Publication date: May 5, 2005
    Inventors: Hiroyuki Matsumoto, Hiroshi Tani, Mitsuhiro Shoda, Koji Sonoda, Takayuki Nakakawaji, Mina Amo, Yutaka Ito
  • Patent number: 6869536
    Abstract: A lubricant which does not splash easily and has an improved property of slidableness, and a magnetic disk using the lubricant are provided. A magnetic disk apparatus featuring a prolonged service life of a stable operation and an excellent record reproduction property is provided by installing the above magnetic disk. The lubricant of the invention contains perfluoropolyether expressed by the following general formula, in which a component of its molecular weights less than 1000 is smaller than 10 wt. %, a component of its molecular weights not less than 7000 is smaller than 15 wt. %, a ratio between a weight average molecular weight and a numeric average molecular weight is 1.5 or less, and a substitution ratio of its terminal functional group is not less than 90%: R1—CF2O—[—(CF2CF2O)—m—(CF2O)—n—]—CF2—R2??(1), where R1 and R2 are univalent organic groups, m and n are positive integers.
    Type: Grant
    Filed: March 13, 2003
    Date of Patent: March 22, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Mina Ishida, Takayuki Nakakawaji, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani, Heigo Ishihara
  • Patent number: 6870704
    Abstract: A low cost and highly reliable lubricating technique is realized by using a lubricant having an average molecular weight in the range of 900 to 2500. The lubricant is efficiently supplied to inner portions of a magnetic disk apparatus utilizing heat generated during operation of the apparatus. The method of assembling the apparatus is not affected since it is not necessary to provide a separate lubricant supply mechanism.
    Type: Grant
    Filed: February 13, 2002
    Date of Patent: March 22, 2005
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Mitsuhiro Shoda, Hiroshi Tani, Hiroyuki Matsumoto, Takayuki Nakakawaji
  • Publication number: 20050047970
    Abstract: A highly reliable reaction container capable of restraining an initial detection failure (bubble attachment), and a biochemical and/or immunological automatic analyzer loaded with the reaction container. In a reaction container made of a synthetic resin and used for receiving a biological sample and a reagent, developing a biochemical and/or immunological reaction between the biological sample and the reagent, and measuring proceedings of the reaction and/or the state at a predetermined point in time by optical means, an inner wall surface of the reaction container in contact with the biological sample, the reagent, and a reaction product of the biological sample and the reagent has a critical surface tension of not smaller than 25.0 mN/m, or a contact angle between the inner wall surface of the reaction container and a solvent of a reaction solution is not larger than 60 degrees.
    Type: Application
    Filed: August 27, 2004
    Publication date: March 3, 2005
    Inventors: Mina Amo, Takayuki Nakakawaji, Taku Sakazume, Katsuhiro Kambara
  • Patent number: 6816341
    Abstract: A recording element or a reproducing element in a head generates heat that decomposes lubricating agent adhered to a slider surface near the recording/reproducing element of the head. This decomposed lubricating agent leads to corrosion of the magnetic layer and the like of the magnetic disk. The lubricating agent undergoes volume expansion due to this corrosion, creating a protrusion on the magnetic disk surface to which the lubricating agent is adhered. The magnetic disk surface to which the lubricating agent is adhered comes into contact with the magnetic head, leading to friction with the protective layer, the magnetic layer, and the like. In the worst case, this can lead to secondary errors where data recorded on the magnetic layer is erased.
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: November 9, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Matsumoto, Hiroshi Tani, Mitsuhiro Shoda, Koji Sonoda, Takayuki Nakakawaji, Mina Amo, Yutaka Ito
  • Publication number: 20040096675
    Abstract: The present invention provides a magnetic recording media made possible to improve reliability and durability of the magnetic recording media with an extremely thin overcoat. A magnetic recording media made by forming at least a magnetic coat and an overcoat on a substrate of non-magnetic magnetic disk on which surface a liquid lubricant having a structure of perfluoropolyether is coated, wherein average roughness of overcoat surface Ra is less than 0.8 nm, said overcoat being a diamond-like-carbon with a thickness in a range of 1.5-4.
    Type: Application
    Filed: July 7, 2003
    Publication date: May 20, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Hiroshi Tani, Hiroyuki Matsumoto, Mitsuhiro Shyoda, Tomonori Kozaki, Takayuki Nakakawaji, Yoko Ogawa
  • Publication number: 20040080864
    Abstract: A magnetic disk drive having a magnetic disk, a spindle motor for rotating the magnetic disk, a magnetic head slider for recording or reproducing data onto or from the magnetic disk and a housing. A control circuit system is provided for controlling the head slider so that the head slider is positioned on the magnetic disk plane when the magnetic disk is rotating, and the head slider is saved to outside the magnetic disk plane when rotation of the magnetic disk is stopped. A lubricant supplier is provided for supplying lubricant to the surface of the magnetic disk. The lubricant supplier contains at least a perfluoropolyether compound having any one of an alcohol group, a cyclic ether group, and an alkyl-ester group at its terminal position as a lubricant, and the lubricant contains the perfluoropolyether compound having a molecular weight sufficient to enable lubrication and no greater than 4000.
    Type: Application
    Filed: October 22, 2003
    Publication date: April 29, 2004
    Inventors: Takayuki Nakakawaji, Mina Ishida, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani
  • Patent number: 6665147
    Abstract: A magnetic disk drive having a small decrease in lubricant film thickness on the surface of the magnetic disk and a superior sliding reliability between the magnetic head and the magnetic disk surface. Perfluoropolyether is supplied as the lubricant onto the surface of the magnetic disk using heat and air flow by applying perfluoropolyether onto the surface of a suspension, or impregnating perfluoropolyether into a filter. The lubricant contains perfluoropolyether having a molecular weight sufficient to enable lubrication and smaller than 4000 by at least 40%.
    Type: Grant
    Filed: July 3, 2001
    Date of Patent: December 16, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Takayuki Nakakawaji, Mina Ishida, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani
  • Publication number: 20030179490
    Abstract: A recording element or a reproducing element in a head generates heat that decomposes lubricating agent adhered to a slider surface near the recording/reproducing element of the head. This decomposed lubricating agent leads to corrosion of the magnetic layer and the like of the magnetic disk. The lubricating agent undergoes volume expansion due to this corrosion, creating a protrusion on the magnetic disk surface to which the lubricating agent is adhered. The magnetic disk surface to which the lubricating agent is adhered comes into contact with the magnetic head, leading to friction with the protective layer, the magnetic layer, and the like. In the worst case, this can lead to secondary errors where data recorded on the magnetic layer is erased.
    Type: Application
    Filed: January 22, 2003
    Publication date: September 25, 2003
    Inventors: Hiroyuki Matsumoto, Hiroshi Tani, Mitsuhiro Shoda, Koji Sonoda, Takayuki Nakakawaji, Mina Amo, Yutaka Ito
  • Publication number: 20030175470
    Abstract: A lubricant which does not splash easily and has an improved property of slidableness, and a magnetic disk using the lubricant are provided. A magnetic disk apparatus featuring a prolonged service life of a stable operation and an excellent record reproduction property is provided by installing the above magnetic disk. The lubricant of the invention contains perfluoropolyether expressed by the following general formula, in which a component of its molecular weights less than 1000 is smaller than 10 wt. %, a component of its molecular weights not less than 7000 is smaller than 15 wt. %, a ratio between a weight average molecular weight and a numeric average molecular weight is 1.
    Type: Application
    Filed: March 13, 2003
    Publication date: September 18, 2003
    Inventors: Mina Ishida, Takayuki Nakakawaji, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani, Heigo Ishihara
  • Patent number: 6605335
    Abstract: The present invention provides a magnetic recording media made possible to improve reliability and durability of the magnetic recording media with an extremely thin overcoat. A magnetic recording media made by forming at least a magnetic coat and an overcoat on a substrate of non-magnetic magnetic disk on which surface a liquid lubricant having a structure of perfluoropolyether is coated, wherein average roughness of overcoat surface Ra is less than 0.8 nm, said overcoat being a diamond-like-carbon with a thickness in a range of 1.5-4.5 nm, and said lubricant on said carbon overcoat containing a lubricant component having a structure represented by chemical formula (1): (where, p=5-36, q=4-30, x=1-5).
    Type: Grant
    Filed: May 22, 2001
    Date of Patent: August 12, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Tani, Hiroyuki Matsumoto, Mitsuhiro Shyoda, Tomonori Kozaki, Takayuki Nakakawaji, Yoko Ogawa
  • Patent number: 6555197
    Abstract: A lubricant which does not splash easily and has an improved property of slidableness, and a magnetic disk using the lubricant are provided. A magnetic disk apparatus featuring a prolonged service life of a stable operation and an excellent record reproduction property is provided by installing the above magnetic disk. The lubricant of the invention contains perfluoropolyether expressed by the following general formula, in which a component of its molecular weights less than 1000 is smaller than 10 wt. %, a component of its molecular weights not less than 7000 is smaller than 15 wt. %, a ratio between a weight average molecular weight and a numeric average molecular weight is 1.5 or less, and a substitution ratio of its terminal functional group is not less than 90%: R1—CF2O—[—(CF2CF2O )—m—(CF2O)—n—]—CF2—R2  (1), where R1 and R2 are univalent organic groups, m and n are positive integers.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: April 29, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Mina Ishida, Takayuki Nakakawaji, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani, Heigo Ishihara
  • Publication number: 20030067711
    Abstract: To achieve a lubricant supply head-disc interface method in which a magnetic disc apparatus can be easily assembled at a low price without providing a special lubricant supply mechanism, lubricant for supply is applied to components-in-magnetic-disc-apparatus and while the apparatus is operated, the lubricant is efficiently supplied utilizing the heat by the operation of the apparatus itself.
    Type: Application
    Filed: February 13, 2002
    Publication date: April 10, 2003
    Inventors: Mitsuhiro Shoda, Hiroshi Tani, Hiroyuki Matsumoto, Takayuki Nakakawaji
  • Publication number: 20020021535
    Abstract: A magnetic disk drive having a small decrease in lubricant film thickness on the surface of the magnetic disk and a superior sliding reliability between the magnetic head and the magnetic disk surface is supplied.
    Type: Application
    Filed: July 3, 2001
    Publication date: February 21, 2002
    Inventors: Takayuki Nakakawaji, Mina Ishida, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani