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).
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Patent number: 10155916Abstract: 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: GrantFiled: February 4, 2016Date of Patent: December 18, 2018Assignee: HITACHI, LTD.Inventors: Takayuki Nakakawaji, Hiroyuki Akata, Tomohiro Moriyama, Kazuhiro Satou, Makoto Hirose
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Publication number: 20170349854Abstract: 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: ApplicationFiled: February 4, 2016Publication date: December 7, 2017Applicant: HITACHI, LTD.Inventors: Takayuki NAKAKAWAJI, Hiroyuki AKATA, Tomohiro MORIYAMA, Kazuhiro SATOU, Makoto HIROSE
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Patent number: 7820114Abstract: 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: GrantFiled: August 27, 2004Date of Patent: October 26, 2010Assignee: Hitachi, Ltd.Inventors: Mina Amo, Takayuki Nakakawaji, Taku Sakazume, Katsuhiro Kambara
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Publication number: 20100195240Abstract: 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: ApplicationFiled: January 29, 2010Publication date: August 5, 2010Inventors: Takayuki Nakakawaji, Mina Amo
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Publication number: 20070270085Abstract: 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: ApplicationFiled: February 27, 2007Publication date: November 22, 2007Inventors: Ryo Ota, Takayuki Nakakawaji, Toranosuke Ashizawa, Naoyuki Koyama
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Patent number: 6917495Abstract: 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: GrantFiled: October 22, 2003Date of Patent: July 12, 2005Assignee: Hitachi, Ltd.Inventors: Takayuki Nakakawaji, Mina Ishida, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani
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Publication number: 20050095461Abstract: 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: ApplicationFiled: November 4, 2004Publication date: May 5, 2005Inventors: Hiroyuki Matsumoto, Hiroshi Tani, Mitsuhiro Shoda, Koji Sonoda, Takayuki Nakakawaji, Mina Amo, Yutaka Ito
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Patent number: 6869536Abstract: 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: GrantFiled: March 13, 2003Date of Patent: March 22, 2005Assignee: Hitachi, Ltd.Inventors: Mina Ishida, Takayuki Nakakawaji, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani, Heigo Ishihara
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Patent number: 6870704Abstract: 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: GrantFiled: February 13, 2002Date of Patent: March 22, 2005Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Mitsuhiro Shoda, Hiroshi Tani, Hiroyuki Matsumoto, Takayuki Nakakawaji
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Publication number: 20050047970Abstract: 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: ApplicationFiled: August 27, 2004Publication date: March 3, 2005Inventors: Mina Amo, Takayuki Nakakawaji, Taku Sakazume, Katsuhiro Kambara
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Patent number: 6816341Abstract: 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: GrantFiled: January 22, 2003Date of Patent: November 9, 2004Assignee: Hitachi, Ltd.Inventors: Hiroyuki Matsumoto, Hiroshi Tani, Mitsuhiro Shoda, Koji Sonoda, Takayuki Nakakawaji, Mina Amo, Yutaka Ito
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Publication number: 20040096675Abstract: 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: ApplicationFiled: July 7, 2003Publication date: May 20, 2004Applicant: Hitachi, Ltd.Inventors: Hiroshi Tani, Hiroyuki Matsumoto, Mitsuhiro Shyoda, Tomonori Kozaki, Takayuki Nakakawaji, Yoko Ogawa
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Publication number: 20040080864Abstract: 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: ApplicationFiled: October 22, 2003Publication date: April 29, 2004Inventors: Takayuki Nakakawaji, Mina Ishida, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani
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Patent number: 6665147Abstract: 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: GrantFiled: July 3, 2001Date of Patent: December 16, 2003Assignee: Hitachi, Ltd.Inventors: Takayuki Nakakawaji, Mina Ishida, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani
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Publication number: 20030179490Abstract: 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: ApplicationFiled: January 22, 2003Publication date: September 25, 2003Inventors: Hiroyuki Matsumoto, Hiroshi Tani, Mitsuhiro Shoda, Koji Sonoda, Takayuki Nakakawaji, Mina Amo, Yutaka Ito
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Publication number: 20030175470Abstract: 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: ApplicationFiled: March 13, 2003Publication date: September 18, 2003Inventors: Mina Ishida, Takayuki Nakakawaji, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani, Heigo Ishihara
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Patent number: 6605335Abstract: 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: GrantFiled: May 22, 2001Date of Patent: August 12, 2003Assignee: Hitachi, Ltd.Inventors: Hiroshi Tani, Hiroyuki Matsumoto, Mitsuhiro Shyoda, Tomonori Kozaki, Takayuki Nakakawaji, Yoko Ogawa
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Patent number: 6555197Abstract: 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: GrantFiled: April 28, 2000Date of Patent: April 29, 2003Assignee: Hitachi, Ltd.Inventors: Mina Ishida, Takayuki Nakakawaji, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani, Heigo Ishihara
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Publication number: 20030067711Abstract: 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: ApplicationFiled: February 13, 2002Publication date: April 10, 2003Inventors: Mitsuhiro Shoda, Hiroshi Tani, Hiroyuki Matsumoto, Takayuki Nakakawaji
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Publication number: 20020021535Abstract: 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: ApplicationFiled: July 3, 2001Publication date: February 21, 2002Inventors: Takayuki Nakakawaji, Mina Ishida, Yutaka Ito, Hiroyuki Matsumoto, Hiroshi Tani