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).
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Publication number: 20180268853Abstract: 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: ApplicationFiled: May 11, 2018Publication date: September 20, 2018Inventors: KOICHI SHIMOKAWA, KATSUSHI HAMAKUBO, KAE ITOH
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Patent number: 9984715Abstract: 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: GrantFiled: November 2, 2015Date of Patent: May 29, 2018Assignee: WD Media, LLCInventors: Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
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Patent number: 9558778Abstract: 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: GrantFiled: March 27, 2010Date of Patent: January 31, 2017Assignee: WD Media (Singapore) Pte. Ltd.Inventors: Kota Suzuki, Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
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Publication number: 20160055874Abstract: 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: ApplicationFiled: November 2, 2015Publication date: February 25, 2016Inventors: Koichi SHIMOKAWA, Katsushi HAMAKUBO, Kae ITOH
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Patent number: 9245568Abstract: 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: GrantFiled: March 27, 2009Date of Patent: January 26, 2016Assignee: WD Media (Singapore) Pte. Ltd.Inventors: Kae Itoh, Katsushi Hamakubo
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Patent number: 9177586Abstract: 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: GrantFiled: September 30, 2009Date of Patent: November 3, 2015Inventors: Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
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Patent number: 9005782Abstract: 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: GrantFiled: March 27, 2009Date of Patent: April 14, 2015Assignee: WD Media, LLCInventors: Katsushi Hamakubo, Kae Itoh
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Patent number: 8920872Abstract: 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: GrantFiled: June 22, 2011Date of Patent: December 30, 2014Assignee: WD Media (Singapore) Pte. Ltd.Inventors: Kae Itoh, Katsushi Hamakubo, Koichi Shimokawa
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Patent number: 8846137Abstract: 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: GrantFiled: February 18, 2010Date of Patent: September 30, 2014Assignee: WD Media (Singapore) Pte. Ltd.Inventors: Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
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Patent number: 8697262Abstract: 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: GrantFiled: June 22, 2011Date of Patent: April 15, 2014Assignee: WD Media (Singapore) Pte. Ltd.Inventors: Katsushi Hamakubo, Kae Itoh, Koichi Shimokawa
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Patent number: 8492011Abstract: 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: GrantFiled: March 26, 2010Date of Patent: July 23, 2013Assignee: WD Media (Singapore) Pte, Ltd.Inventors: Kae Itoh, Katsushi Hamakubo, Koichi Shimokawa
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Publication number: 20120225217Abstract: 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: ApplicationFiled: June 22, 2011Publication date: September 6, 2012Applicant: WD MEDIA (SINGAPORE) PTE. LTD.Inventors: KAE ITOH, KATSUSHI HAMAKUBO, KOICHI SHIMOKAWA
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Publication number: 20120148875Abstract: 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: ApplicationFiled: June 22, 2011Publication date: June 14, 2012Applicant: WD MEDIA (SINGAPORE) PTE. LTD.Inventors: Katsushi Hamakubo, Kae Itoh, Koichi Shimokawa
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Publication number: 20120127601Abstract: 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: ApplicationFiled: March 27, 2010Publication date: May 24, 2012Applicant: WD MEDIA (SINGAPORE) PTE. LTD.Inventors: Kota Suzuki, Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
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Publication number: 20120127599Abstract: 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: ApplicationFiled: September 30, 2009Publication date: May 24, 2012Applicant: WD MEDIA (SINGAPORE) PTE. LTD.Inventors: Koichi Shimokawa, Katsushi Hamakubo, Kae Itoh
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Publication number: 20110026162Abstract: 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: ApplicationFiled: March 27, 2009Publication date: February 3, 2011Applicant: HOYA CORPORATIONInventors: Katsushi Hamakubo, Kae Itoh
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Publication number: 20100261039Abstract: 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: ApplicationFiled: March 27, 2009Publication date: October 14, 2010Applicant: HOYA CORPORATIONInventors: Kae Itoh, Katsushi Hamakubo
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Publication number: 20100246064Abstract: 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: ApplicationFiled: March 26, 2010Publication date: September 30, 2010Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.Inventors: Kae ITOH, Katsushi HAMAKUBO, Koichi SHIMOKAWA
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Publication number: 20100209601Abstract: 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: ApplicationFiled: February 18, 2010Publication date: August 19, 2010Applicants: HOYA CORPORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.Inventors: Koichi SHIMOKAWA, Katsushi HAMAKUBO, Kae ITOH