Perfluoropolyether Patents (Class 428/835.8)
  • Patent number: 7682712
    Abstract: 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: Grant
    Filed: December 9, 2005
    Date of Patent: March 23, 2010
    Assignee: Seagate Technology LLC
    Inventors: Jianwei Liu, Michael Joseph Stirniman, Jing Gui
  • Patent number: 7510999
    Abstract: 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: Grant
    Filed: May 28, 2004
    Date of Patent: March 31, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hong Deng, Robert Waltman, Jinliu Wang
  • Patent number: 7354666
    Abstract: 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: Grant
    Filed: March 25, 2005
    Date of Patent: April 8, 2008
    Assignee: Seagate Technology LLC
    Inventors: Jianwei Liu, Michael Joseph Stirniman
  • Patent number: 7277254
    Abstract: 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: Grant
    Filed: April 4, 2005
    Date of Patent: October 2, 2007
    Assignee: Hoya Corporation
    Inventors: Koichi Shimokawa, Kota Hara
  • Publication number: 20070224452
    Abstract: 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: Application
    Filed: September 5, 2006
    Publication date: September 27, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Masaaki Sasa, Hiroshi Chiba
  • Patent number: 7252897
    Abstract: 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: Grant
    Filed: September 3, 2003
    Date of Patent: August 7, 2007
    Assignee: Hoya Corporation
    Inventors: Koichi Shimokawa, Kota Hara
  • Patent number: 7247397
    Abstract: 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: Grant
    Filed: December 9, 2003
    Date of Patent: July 24, 2007
    Assignee: Imation Corp.
    Inventor: Ramon F. Hegel
  • Patent number: 7199087
    Abstract: 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: Grant
    Filed: July 17, 2003
    Date of Patent: April 3, 2007
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventors: Yoshihito Osawa, Shinji Shirai, Masayuki Ishkawa
  • Patent number: 7105241
    Abstract: 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: Grant
    Filed: March 26, 2004
    Date of Patent: September 12, 2006
    Assignees: Hoya Corporation, Hoya Magnetics Singapore Pte. Ltd.
    Inventors: Koichi Shimokawa, Masafumi Ishiyama