Perfluoropolyether Patents (Class 428/835.8)
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Patent number: 7682712Abstract: A data/information storage and retrieval medium comprises: (a) a substrate having a layer stack thereon, the layer stack including an outer surface and comprising at least one magnetic or magneto-optical (“MO”) recording layer; and (b) a thin film or layer of a lubricant on the outer surface of the layer stack and comprised of a derivatized perfluoropolyether-based material including at least one generally linear perfluoropolyether chain and at least one phosphite antioxidant/stabilizer moiety attached to at least one end of at least one the chain.Type: GrantFiled: December 9, 2005Date of Patent: March 23, 2010Assignee: Seagate Technology LLCInventors: Jianwei Liu, Michael Joseph Stirniman, Jing Gui
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Patent number: 7510999Abstract: A lubricant composition is provided comprising a first liquid lubricant and a second liquid lubricant, wherein the first liquid lubricant contains a cyclotriphosphazene ring attached to at least one perfluoropolyether having a single terminal hydroxyl group, and the second liquid lubricant contains a perfluoropolyether having two end groups selected from hydroxyl, tertiary amine, and combinations thereof. A magnetic recording media is also provided, comprising a substrate, a magnetic layer, an overcoat layer and a lubricant layer thereon, wherein the lubricant layer is formed from the lubricant composition. A further aspect of the invention concerns a method of making a magnetic recording media comprising forming a magnetic layer on a substrate; forming a protective overcoat layer on the magnetic layer; and forming a lubricant layer on the surface of the overcoat layer by applying the lubricant composition to the surface of the overcoat layer.Type: GrantFiled: May 28, 2004Date of Patent: March 31, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hong Deng, Robert Waltman, Jinliu Wang
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Patent number: 7354666Abstract: A system and method for improving the durability and reliability of recording media used in hard drives is disclosed. A protective overcoat made of diamond like carbon (DLC) is first deposited over a magnetic layer. A lubricant layer, typically containing Moresco lubricant or a perfluoropolyether (PFPE), is then deposited over the protective overcoat. Finally, the lubricant layer is exposed to ultraviolet (UV) light for a period of time.Type: GrantFiled: March 25, 2005Date of Patent: April 8, 2008Assignee: Seagate Technology LLCInventors: Jianwei Liu, Michael Joseph Stirniman
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Patent number: 7277254Abstract: A magnetic recording disk having a substrate, a magnetic layer formed on the substrate, a protective layer formed on the magnetic layer and a lubricant layer formed on the protective layer, the lubricant layer containing a perfluoropolyether compound having an end moiety containing a phosphazene ring and a perfluoropolyether compound having an end moiety containing a hydroxyl group, or the lubricant layer containing a perfluoropolyether compound having an end moiety containing a hydroxyl group on the protective layer side and a perfluoropolyether compound having an end moiety containing a phosphazene ring on the other surface side, and a process for manufacturing each of these magnetic recording disks.Type: GrantFiled: April 4, 2005Date of Patent: October 2, 2007Assignee: Hoya CorporationInventors: Koichi Shimokawa, Kota Hara
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Publication number: 20070224452Abstract: A lubricant is provided that can form a sufficiently thin one-molecule film surface even when it is highly polymerized. When used for a magnetic recording medium lubricant layer and/or a head slider lubricant layer of a magnetic recording device, it can make the film thickness of the lubricant layers very small, with the result that it can furnish an increased reliability to the magnetic recording device in a wide temperature-range environment without damaging the flying stability. This lubricant comprises a fluorine-containing polymer having a specific structure. Such a fluorine-containing polymer can be manufactured by reacting a compound having a specific structure and 1,3-butadiene diepoxide.Type: ApplicationFiled: September 5, 2006Publication date: September 27, 2007Applicant: FUJITSU LIMITEDInventors: Masaaki Sasa, Hiroshi Chiba
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Patent number: 7252897Abstract: A magnetic recording disk having a substrate, a magnetic layer formed on the substrate, a protective layer formed on the magnetic layer and a lubricant layer formed on the protective layer, the lubricant layer containing a perfluoropolyether compound having an end moiety containing a phosphazene ring and a perfluoropolyether compound having an end moiety containing a hydroxyl group, or the lubricant layer containing a perfluoropolyether compound having an end moiety containing a hydroxyl group on the protective layer side and a perfluoropolyether compound having an end moiety containing a phosphazene ring on the other surface side, and a process for manufacturing each of these magnetic recording disks.Type: GrantFiled: September 3, 2003Date of Patent: August 7, 2007Assignee: Hoya CorporationInventors: Koichi Shimokawa, Kota Hara
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Patent number: 7247397Abstract: The invention provides a lubricant useful in magnetic recording media and optical recording media comprising a functionalized perfluoropolyether comprising multiple acrylate endgroups. More specifically, the lubricant of the invention is a functionalized perfluoropolyether comprising at least about two acrylate groups. In one embodiment, the lubricant of the invention is a functionalized perfluoropolyether comprising a perfluoropolyether tetraacrylate. A magnetic recording medium is also provided comprising a thin metal magnetic recording layer, said layer having a coating of the functionalized perfluoropolyether lubricant comprising at least about three acrylate end groups.Type: GrantFiled: December 9, 2003Date of Patent: July 24, 2007Assignee: Imation Corp.Inventor: Ramon F. Hegel
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Patent number: 7199087Abstract: A method refines a lubricant comprising a compound having a perfluoropolyether structure via supercritical extraction. A lubricant is refined using the method and a magnetic recording medium that utilizes the refined lubricant. The refined lubricant exhibits excellent lubrication performance and long term stability in the magnetic recording medium. In one embodiment of the supercritical extraction, the lubricant contacts an extracting medium of supercritical carbon dioxide under a predetermined condition in a pressure vessel to remove ionic impurities and perfluoropolyether compounds having a weak polarity terminal group contained in the lubricant.Type: GrantFiled: July 17, 2003Date of Patent: April 3, 2007Assignee: Fuji Electric Device Technology Co., Ltd.Inventors: Yoshihito Osawa, Shinji Shirai, Masayuki Ishkawa
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Patent number: 7105241Abstract: Disclosed is a method of manufacturing magnetic disks, comprising a magnetic layer, a protective layer, and a lubricating layer on a substrate. In the process, a lubricant alpha comprising a compound denoted by chemical formula HO—CH2—CH(OH)—CH2—O—CH2—CF2(—O—C2F4)p-(O—CF2)q-O—CF2—CH2—O—CH2—CH(OH)—CH2—OH wherein p and q are natural number, and a compound denoted by chemical formula HO—CH2—CF2(—O—C2F4)m-(O—CF2)n-O—CF2—CH2—OH wherein m and n are natural number, is fractionated by molecular weight to prepare a lubricant a having a weight average molecular weight (Mw) of from 3,000 to 7,000 and a molecular weight dispersion of less than or equal to 1.2; a lubricant beta comprising a compound denoted by the chemical formula HO—CH2—CF2(—O—C2F4)m-(O—CF2)n-O—CF2—CH2—OH wherein m and n are natural number, is fractionated by molecular weight to prepare a lubricant b having a weight average molecular weight (Mw) of from 2,000 to 5,000 and a molecular weight dispersion of less than or equal to 1.Type: GrantFiled: March 26, 2004Date of Patent: September 12, 2006Assignees: Hoya Corporation, Hoya Magnetics Singapore Pte. Ltd.Inventors: Koichi Shimokawa, Masafumi Ishiyama