Patents by Inventor Kae ITOH

Kae ITOH 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).

  • Publication number: 20180268853
    Abstract: A magnetic disk of is provided, the magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate. In an embodiment, the lubrication layer a film formed by a lubricant having a perfluoropolyether compound A having a perfluoropolyether main chain in the structure and also having a hydroxyl group at the end and a compound C obtained from a reaction between a compound B expressed by: [Chemical formula 1] CF3(—O—C2F4)m-(O—CF2)n-OCF3 [m and n in the formula are natural numbers.] and aluminum oxide.
    Type: Application
    Filed: May 11, 2018
    Publication date: September 20, 2018
    Inventors: KOICHI SHIMOKAWA, KATSUSHI HAMAKUBO, KAE ITOH
  • Patent number: 9984715
    Abstract: A magnetic disk of is provided, the magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate. In an embodiment, the lubrication layer a film formed by a lubricant having a perfluoropolyether compound A having a perfluoropolyether main chain in the structure and also having a hydroxyl group at the end and a compound C obtained from a reaction between a compound B expressed by: [Chemical formula 1] CF3(—O—C2F4)m-(O—CF2)n-OCF3 [m and n in the formula are natural numbers.] and aluminum oxide.
    Type: Grant
    Filed: November 2, 2015
    Date of Patent: May 29, 2018
    Assignee: WD Media, LLC
    Inventors: Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
  • Patent number: 9558778
    Abstract: A lubricant compound is contained in a lubrication layer of a magnetic disk in which at least a magnetic layer, a protective layer, and a lubrication layer are sequentially provided on a substrate, and the lubricant compound contains a component A represented by Chemical formula 1 and a component B represented by Chemical formula 2: wherein X in Chemical formula 1 represents OH wherein X in Chemical formula 2 represents OCH2CH(OH)CH2OH, and the lubricant compound further contains a component C made of a specific compound having a phosphezene ring in the structure thereof.
    Type: Grant
    Filed: March 27, 2010
    Date of Patent: January 31, 2017
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Kota Suzuki, Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
  • Publication number: 20160055874
    Abstract: A magnetic disk of is provided, the magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate. In an embodiment, the lubrication layer a film formed by a lubricant having a perfluoropolyether compound A having a perfluoropolyether main chain in the structure and also having a hydroxyl group at the end and a compound C obtained from a reaction between a compound B expressed by: [Chemical formula 1] CF3(—O—C2F4)m-(O—CF2)n-OCF3 [m and n in the formula are natural numbers.] and aluminum oxide.
    Type: Application
    Filed: November 2, 2015
    Publication date: February 25, 2016
    Inventors: Koichi SHIMOKAWA, Katsushi HAMAKUBO, Kae ITOH
  • Patent number: 9245568
    Abstract: Disclosed is a magnetic disk that has excellent durability, particularly excellent LUL durability, and excellent alumina resistance and has a high level of reliability under a low flying height of a magnetic head involved in a recent tendency toward a rapid increase in recording density and a very severe environment resistance requirement due to diversified applications. A magnetic disk (10) comprises a substrate (1) and at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in that order over the substrate (1). The lubricating layer (8) contains a compound that has a perfluoropolyether main chain in the structure thereof and has an aromatic group and a polar group at the end of the molecule.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: January 26, 2016
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Kae Itoh, Katsushi Hamakubo
  • Patent number: 9177586
    Abstract: A magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate. The lubrication layer is a film formed by a lubricant that contains two types of compounds having a perfluoropolyether main chain in the structure, a molecular weight distribution of the two types in total being within a range of 1 to 1.2. The two types of compounds include a compound a having a hydroxyl group at the end and a compound b having a number average molecular weight smaller than the number average molecular weight of the compound a and not more than 1500. A content of the compound b in the two types of compounds is not more than 10%.
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: November 3, 2015
    Inventors: Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
  • Patent number: 9005782
    Abstract: Provided is a magnetic disk that is excellent in durability, particularly in LUL durability and CFT properties, and thus has high reliability despite the low flying height of a magnetic head following the rapid increase in recording density in recent years and despite the very strict environmental resistance following the diversification of applications. A magnetic disk (10) has at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in this order over a substrate (1). The lubricating layer (8) contains a compound having a perfluoropolyether main chain in a structure thereof and having a polar group other than at ends of a molecule thereof.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: April 14, 2015
    Assignee: WD Media, LLC
    Inventors: Katsushi Hamakubo, Kae Itoh
  • Patent number: 8920872
    Abstract: A method of manufacturing a magnetic disk in which at least a magnetic layer, a carbon protective layer, and a lubrication layer are sequentially formed on a substrate is provided. The method comprises forming a film of a lubricant composition on the protective layer, the lubricant comprising a lubricant compound having a perfluoropolyether main chain in the molecular structure and an aromatic group or a phosphazene ring. The method further comprises forming the lubrication layer, and subjecting the magnetic disk to ultraviolet irradiation under a nitrogen gas or an inert gas atmosphere having an oxygen concentration of 5 volume % or less by adjusting an atmospheric temperature to a range of 50 to 180° C.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: December 30, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Kae Itoh, Katsushi Hamakubo, Koichi Shimokawa
  • Patent number: 8846137
    Abstract: On manufacturing a magnetic disk having at least a magnetic layer (60), a protective layer (70), and a lubricating layer (80) formed in this order over a substrate (10), the lubricating layer is formed by using a coating solution in which a perfluoropolyether compound having a perfluoropolyether main chain and a hydroxyl group in a structure thereof is dispersed and dissolved in a fluorine-based solvent having a boiling point of 90° C. or more.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: September 30, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
  • Patent number: 8697262
    Abstract: A magnetic disk in which at least a magnetic layer, a protective layer, and the lubrication layer are sequentially provided on a substrate, the lubrication layer contains a lubricant compound for a magnetic disk, having a perfluoropolyether main chain in the molecular structure and a structure indicated as follows at a position close to the center of the molecule: -0-CH2—CH(OH)—CH2—CH2—CH(OH)—CH2-0- or -0-CH2—CH(OH)—CH(OH)—CH2-0-.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: April 15, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Katsushi Hamakubo, Kae Itoh, Koichi Shimokawa
  • Patent number: 8492011
    Abstract: In a magnetic disk that has at least a magnetic layer, a carbon-based protective layer, and a lubricating layer formed in this order over a substrate, the lubricating layer contains a lubricant compound including a compound which has a perfluoropolyether main chain in a structure thereof, an aromatic group located at a position except each end of a molecule thereof, and a polar group at each end of the molecule.
    Type: Grant
    Filed: March 26, 2010
    Date of Patent: July 23, 2013
    Assignee: WD Media (Singapore) Pte, Ltd.
    Inventors: Kae Itoh, Katsushi Hamakubo, Koichi Shimokawa
  • Publication number: 20120225217
    Abstract: A method of manufacturing a magnetic disk in which at least a magnetic layer, a carbon protective layer, and a lubrication layer are sequentially formed on a substrate is provided. The method comprises forming a film of a lubricant composition on the protective layer, the lubricant comprising a lubricant compound having a perfluoropolyether main chain in the molecular structure and an aromatic group or a phosphazene ring. The method further comprises forming the lubrication layer, and subjecting the magnetic disk to ultraviolet irradiation under a nitrogen gas or an inert gas atmosphere having an oxygen concentration of 5 volume % or less by adjusting an atmospheric temperature to a range of 50 to 180° C.
    Type: Application
    Filed: June 22, 2011
    Publication date: September 6, 2012
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: KAE ITOH, KATSUSHI HAMAKUBO, KOICHI SHIMOKAWA
  • Publication number: 20120148875
    Abstract: A magnetic disk with which further reduction of magnetic spacing can be realized and which has high reliability under such circumstances of a lower floating amount of a magnetic head involved in the recent rapid increase in recording density and of extremely severe environmental resistance involved in diversification in use applications is provided.
    Type: Application
    Filed: June 22, 2011
    Publication date: June 14, 2012
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Katsushi Hamakubo, Kae Itoh, Koichi Shimokawa
  • Publication number: 20120127601
    Abstract: A lubricant compound for a magnetic disk is provided which can realize further reduction of the magnetic spacing and moreover, has high reliability under a lower floating amount of the magnetic head involved with the recent rapid increase in the recording density and under extremely severe environmental resistance involved with diversification of the applications. A lubricant compound is contained in a lubrication layer of a magnetic disk in which at least a magnetic layer, a protective layer, and a lubrication layer are sequentially provided on a substrate, and the lubricant compound contains a component A and a component B expressed by the following chemical formula: [Chemical formula] 1 Component A: X=OH Component B: X=OCH2CH(OH)CH2OH and a component C made of a specific compound having a phosphezene ring in the structure thereof.
    Type: Application
    Filed: March 27, 2010
    Publication date: May 24, 2012
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Kota Suzuki, Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
  • Publication number: 20120127599
    Abstract: A magnetic disk is provided which is excellent in durability of the magnetic disk or particularly in LUL durability and CFT characteristics and has high reliability under a decreased floating amount of the magnetic head accompanying the recent rapid increase in a recording density and extremely severe environmental resistance accompanying diversification of the applications. The magnetic disk of the present invention is a magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate, and the lubrication layer is a film formed by a lubricant that contains two types of compounds having a perfluoropolyether main chain in the structure, a molecular weight distribution of the two types in total being within a range of 1 to 1.
    Type: Application
    Filed: September 30, 2009
    Publication date: May 24, 2012
    Applicant: WD MEDIA (SINGAPORE) PTE. LTD.
    Inventors: Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
  • Publication number: 20110026162
    Abstract: Provided is a magnetic disk that is excellent in durability, particularly in LUL durability and CFT properties, and thus has high reliability despite the low flying height of a magnetic head following the rapid increase in recording density in recent years and despite the very strict environmental resistance following the diversification of applications. A magnetic disk (10) has at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in this order over a substrate (1). The lubricating layer (8) contains a compound having a perfluoropolyether main chain in a structure thereof and having a polar group other than at ends of a molecule thereof.
    Type: Application
    Filed: March 27, 2009
    Publication date: February 3, 2011
    Applicant: HOYA CORPORATION
    Inventors: Katsushi Hamakubo, Kae Itoh
  • Publication number: 20100261039
    Abstract: Disclosed is a magnetic disk that has excellent durability, particularly excellent LUL durability, and excellent alumina resistance and has a high level of reliability under a low flying height of a magnetic head involved in a recent tendency toward a rapid increase in recording density and a very severe environment resistance requirement due to diversified applications. A magnetic disk (10) comprises a substrate (1) and at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in that order over the substrate (1). The lubricating layer (8) contains a compound that has a perfluoropolyether main chain in the structure thereof and has an aromatic group and a polar group at the end of the molecule.
    Type: Application
    Filed: March 27, 2009
    Publication date: October 14, 2010
    Applicant: HOYA CORPORATION
    Inventors: Kae Itoh, Katsushi Hamakubo
  • Publication number: 20100246064
    Abstract: In a magnetic disk has at least a magnetic layer, a carbon-based protective layer, and a lubricating layer formed in this order over a substrate, the lubricating layer contains a lubricant compound including a compound which has a perfluoropolyether main chain in a structure thereof, an aromatic group located at a position except each end of a molecule thereof, and a polar group at each end of the molecule.
    Type: Application
    Filed: March 26, 2010
    Publication date: September 30, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Kae ITOH, Katsushi HAMAKUBO, Koichi SHIMOKAWA
  • Publication number: 20100209601
    Abstract: On manufacturing a magnetic disk having at least a magnetic layer (60), a protective layer (70), and a lubricating layer (80) formed in this order over a substrate (10), the lubricating layer is formed by using a coating solution in which a perfluoropolyether compound having a perfluoropolyether main chain and a hydroxyl group in a structure thereof is dispersed and dissolved in a fluorine-based solvent having a boiling point of 90° C. or more.
    Type: Application
    Filed: February 18, 2010
    Publication date: August 19, 2010
    Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Koichi SHIMOKAWA, Katsushi HAMAKUBO, Kae ITOH