Single Magnetic Layer With Plural Overcoat Layers Patents (Class 428/833)
  • Patent number: 10047317
    Abstract: Disclosed is a fluoropolyether compound comprising a C4-10 aliphatic hydrocarbon chain present in the middle of the fluoropolyether compound and at least two perfluoropolyethers.
    Type: Grant
    Filed: November 24, 2015
    Date of Patent: August 14, 2018
    Assignee: Moresco Corporation
    Inventors: Ryosuke Sagata, Tsuyoshi Shimizu, Haruo Kasai
  • Patent number: 10047316
    Abstract: The disclosure provides a fluoropolyether compound represented by formula (1): R1—CH2—R2—CH2—R3 wherein R1 is C1-C10 alkoxy; R2 is —(CF2)pO(CF2O)x(CF2CF2O)y(CF2CF2CF2O)z(CF2CF2CF2CF2O)w(CF2)p—; x and y are each a real number of 0 to 30; z is a real number of 0 to 30; w is a real number of 0 to 20; p is an integer of 1 to 3; R3 is —OCH2CH(OH)CH2OH, —OCH2CH(OH)CH2OCH2CH(OH)CH2OH, —O(CH2)mOH, or —OCH2(OH)CHCH2—OC6H4—R4; m is an integer of 2 to 8; and R4 is hydrogen, C1-C4 alkoxy, amino, or an amide residue; and also provides a lubricant having the compound and a magnetic disk.
    Type: Grant
    Filed: June 22, 2015
    Date of Patent: August 14, 2018
    Assignee: Moresco Corporation
    Inventors: Ryosuke Sagata, Haruo Kasai
  • Patent number: 8947987
    Abstract: Aspects of the present invention are directed to heat assisted magnetic recording (HAMR) media with a CoCrPtB based capping layer design that is capable of reducing switching field distribution and boosting signal-to-noise ratio of HAMR media. In one embodiment of the invention, a recording medium for heat assisted magnetic recording (HAMR) includes a substrate, a magnetic recording layer on the substrate, and a capping layer on and directly in contact with the magnetic recording layer. The capping layer includes CoCrPtB.
    Type: Grant
    Filed: July 1, 2013
    Date of Patent: February 3, 2015
    Assignee: WD Media, LLC
    Inventors: Bincheng Wang, Alexander S. Chernyshov, Hua Yuan, Tomoko Seki, Antony Ajan, B. Ramamurthy Acharya
  • Publication number: 20150017483
    Abstract: Provided herein is a method including oxidizing tops of features of a patterned magnetic layer to form oxidized tops of the features; removing an excess of an applied first protective material down to at least the oxidized tops of the features to form a planarized layer; and applying a second protective material over the planarized layer.
    Type: Application
    Filed: October 24, 2013
    Publication date: January 15, 2015
    Applicant: Seagate Technology LLC
    Inventors: Michael R. Feldbaum, Wago Wago, Bin Lu, David S. Kuo
  • Publication number: 20140368947
    Abstract: In one embodiment, a magnetic recording medium includes a magnetic recording layer adapted to store magnetic information, a protective film positioned above the recording layer, the protective film being adapted to reduce wear to the magnetic recording layer, and a lubricant positioned above the protective film, the lubricant being adapted to provide a stable head-to-disk interface, wherein the lubricant includes a first lubricant, the first lubricant including a material having the following chemical formula: wherein Rf represents: and wherein Y is a repeating chain including carbon and fluorine.
    Type: Application
    Filed: June 14, 2013
    Publication date: December 18, 2014
    Inventors: Yoko Saito, Hiroyuki Matsumoto, Sukefumi Ito, Yoshihiko Ooeda
  • Publication number: 20140349140
    Abstract: To provide a CxNyHz film of high density and a deposition method. One aspect of the present invention is a CxNyHz film formed on a substrate to be deposited, wherein x, y and z satisfy formulae (1) to (4) below: 0.4<x<0.7??(1) 0.01<y<0.5??(2) 0?z<0.3??(3) x+y+z=1.
    Type: Application
    Filed: October 24, 2011
    Publication date: November 27, 2014
    Inventors: Haruhito Hayakawa, Kouji Abe, Keiichi Terashima, Yuuji Honda
  • Publication number: 20140234666
    Abstract: A novel lubricant comprising a perfluoropoyether (PFPE) molecule terminated with a benzene molecule or a functional benzene molecule for a magnetic recording media structure is disclosed. The magnetic recording media structure includes a substrate, a magnetic recording layer for recording information disposed over the substrate, a protective overcoat layer for protecting the magnetic recording layer disposed over the magnetic recording layer, and a lubricant layer disposed over the protective overcoat layer and comprising a perfluoropoyether (PFPE) molecule terminated with a benzene molecule or a functional benzene molecule.
    Type: Application
    Filed: February 19, 2013
    Publication date: August 21, 2014
    Applicant: WD MEDIA, INC.
    Inventor: WD Media, Inc.
  • Publication number: 20140141284
    Abstract: A compound of Formula (I) includes: [L]1-[N]n—OCH2CF2O(CF2CF2O)p(CF2O)qCF2CH2O—[M]m, where L is selected from the group consisting of (AA) M is selected from the group consisting of (BB) and N is (CC) where R1, R2, and R3 may be the same or different, and are selected from the group consisting of hydroxyl, phenyl, piperonyl, carboxylic acid, amide, 2,3-di-hydroxy-1-propoxyl, acetamide, methacrylate, methyl methacrylate and glycidyl ether; and where 1=0, 1, or 2, m=0, 1, or 2, n=1 or 2, and the ratio of p to q is from about 0.1 to 3.0.
    Type: Application
    Filed: June 7, 2011
    Publication date: May 22, 2014
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Jiping Yang, Michael Joseph Stirniman
  • Patent number: 8724435
    Abstract: According to one embodiment, in a magnetic disk, a reflecting layer with a higher reflectance to near-field light than a magnetic recording layer is provided in the magnetic recording layer so as to be flat. A magnetic head performs magnetic recording on the magnetic recording layer while locally heating the magnetic recording layer based on the near-field light.
    Type: Grant
    Filed: February 27, 2013
    Date of Patent: May 13, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Isokawa, Tomoko Taguchi
  • Publication number: 20140099518
    Abstract: Disclosed herein are compounds of formula I: X-(L-Z)p-L-R[L-(Z-L)p-Y]q??(I) wherein L is a perfluoropolyether; R is q can be an integer equal to or greater than 1; p can independently be integers from 0 to 7; X and Y can independently be chosen from: —OH, —CH2CH2OH, CH2CH2OCH2CH2OH, —CH2CH(OH)CH2OH, —C6H5, —CH2C6H5, —CH2CH(OH)CH3, F, —CF3, —CF2CF3, piperonyl, triazine, benzotriazole, and derivatives thereof; and Z, if present, can independently be chosen from: —C6H4—, —CH2C6H4CH2—, —CH2CH(OH)CH2—, —CH2CH(OH)CH2CH(OH)CH2—, —CH(OH)CH(OH)CH2—, —CH(CH2OH)—, or —CH(C6H5)—.
    Type: Application
    Filed: October 5, 2012
    Publication date: April 10, 2014
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiaoping Yan, Michael Stirniman, Qian Guo, Wenhong Liu
  • Publication number: 20140029137
    Abstract: According to one embodiment, letting (Rf) be main-chain portion C2F4O contained in a Fomblin lubricant and a compound containing a phosphazene ring and (R) be terminal group (CF3—C6H4—O—)5(NP)5—O—CH2CF2 contained in the compound containing a phosphazene ring in a magnetic recording medium, the ratio, which is measured using TOF-SIMS, of the component of (R) to the component of (Rf) on the surface of a lubricant layer is 0.01 to 0.09%.
    Type: Application
    Filed: December 10, 2012
    Publication date: January 30, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takayuki MUSASHI, Hiroyuki HYODO
  • Publication number: 20140011054
    Abstract: A perpendicular magnetic recording medium, including a suitable lubricating layer with sufficient durability, moisture resistance, and contamination resistance and also maintaining an R/W characteristic. The perpendicular magnetic recording medium 100 includes a magnetic recording layer 122, a medium protective layer 126, and a lubricating layer 128 in this order on a base 110. The medium is made using a CF bond density measuring step of measuring a CF bond density of a lubricant; and a lubricating layer forming step of forming a lubricating layer with the lubricant when the measured CF bond density is 2.0×1022 to 2.7×1022 atoms/cm3.
    Type: Application
    Filed: September 8, 2013
    Publication date: January 9, 2014
    Applicant: WD Media (Singapore) Pte. Ltd.
    Inventor: Kouta SUZUKI
  • Patent number: 8614862
    Abstract: In one general embodiment, a perpendicular magnetic recording medium includes a ferromagnetic granular layer with perpendicular magnetic anisotropy and having a granular structure; and a cap layer above said granular layer, the cap layer being a ferromagnetic continuous layer with perpendicular magnetic anisotropy, wherein, near a first side of said granular layer nearest the cap layer. Surfaces of the ferromagnetic grains of said granular layer facing the cap layer each have a domed shape defining undulations along the first side. Indentations in said ferromagnetic grains are filled by the oxide of the grain boundary in a vicinity of the first side of said granular layer. Undulations on a granular layer side of said cap layer are flatter than the undulations of the ferromagnetic grains on the first side of said granular layer.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: December 24, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Masayoshi Shimizu, Hiroyuki Nakagawa, Shun Tonooka, Yoshinori Honda
  • Publication number: 20130288080
    Abstract: Compounds of formula I: wherein X are independently —(CH2)b—, wherein b is 0 or an integer from 1 to 6; Rf are independently —CF2O(CF2CF2O)p(CF2)qCF2—, —CF2CF2O(CF2CF2CF2O)rCF2CF2—, or —CF2CF2CF2O(CF2CF2CF2CF2O)sCF2CF2CF2—, or derivatives thereof, wherein p, q, r and s are independently integers so that Mn of Rf is about 150 to 4500; and Z are independently chosen from groups that comprise —OH, —(OH)2, —COOCH3, —F, —CF3, or —CF2CF3, with the caveat that not all Z are the same.
    Type: Application
    Filed: April 25, 2012
    Publication date: October 31, 2013
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiaoping Yan, Michael Josesph Stirniman
  • Publication number: 20130209837
    Abstract: A compound of the formula (1), lubricant containing the compound and magnetic disk R1—C6H4O—CH2CH(OH)CH2OCH2—R2—CH2—O—R3??(1) wherein R1 is hydrogen, alkoxyl having 1 to 4 carbon atoms, amino or amido, R2 is —CF2O(CF2CF2O)x(CF2O)yCF2—, —CF2CF2O(CF2CF2CF2O)z—CF2CF2— or —CF2CF2CF2O(CF2CF2CF2CF2O)nCF2CF2CF2—, x and y are each an integer of 0 to 15, z is an integer of 1 to 15, n is an integer of 0 to 4, R3 is —CH2CH(OH)CH2OH, —CH2CH(OH)CH2OCH2CH(OH)CH2OH or —(CH2)mOH, m is an integer of 2 to 6.
    Type: Application
    Filed: February 13, 2013
    Publication date: August 15, 2013
    Applicant: MORESCO CORPORATION
    Inventor: MORESCO Corporation
  • Publication number: 20130194693
    Abstract: According to one embodiment, a lubricant includes a perfluoropolyether having a chemical structure of wherein Rf is at least one of —CF2O(CF2CF2O)m(CF2O)nCF2— and —CF2CF2O(CF2CF2CF2O)kCF2CF2—, with m representing 0 or a positive integer, n representing 0 or a positive integer, and k representing 0 or a positive integer, and wherein R1 to R4 are selected from a group consisting of —H or with at least one of R1 to R4 being
    Type: Application
    Filed: January 30, 2012
    Publication date: August 1, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Mina Amo, Katsumi Mabuchi, Hiroshi Yoshida, Bruno Marchon, Qing Dai
  • Publication number: 20130175646
    Abstract: Magnetic structures, methods of forming the same, and memory devices including a magnetic structure, include a magnetic layer, and a stress-inducing layer on a first surface of the magnetic layer, a non-magnetic layer on a second surface of the magnetic layer. The stress-inducing layer is configured to induce a compressive stress in the magnetic layer. The magnetic layer has a lattice structure compressively strained due to the stress-inducing layer.
    Type: Application
    Filed: July 16, 2012
    Publication date: July 11, 2013
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Kwang-seok Kim, Sung-chul Lee
  • Publication number: 20130052485
    Abstract: A perpendicular magnetic recording stack with a dual continuous layer and a method of manufacturing the same. The perpendicular magnetic recording stack includes a substrate, one or more magnetic granular recording layers, and a dual continuous layer having first and second continuous layers. The first continuous layer, disposed between the second continuous layer and the magnetic granular recording layers, has an intermediate lateral exchange coupling, which is higher than the lateral exchange coupling of the magnetic granular layers. The second continuous layer has a higher lateral exchange coupling than the first continuous layer.
    Type: Application
    Filed: August 25, 2011
    Publication date: February 28, 2013
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Zhong Wu, Li Tang, Shoutao Wang, Abebe Hailu
  • Publication number: 20120295134
    Abstract: An object of the present invention is to provide a compound (lubricant) that exhibits better fluidity and adsorbability on the surface of a disk than conventional end-modified compounds, that is thermally stable, and that is obtained by introducing an additional functional group to the end(s) of a perfluoropolyether having a hydroxy group. The present invention relates to a lubricant comprising a perfluoropolyether compound containing, in the molecule, a group represented by Formula (2), wherein R represents a hydrogen, a C1-10 alkyl group, or an alkoxy group, and n is 1 or 2.
    Type: Application
    Filed: February 10, 2010
    Publication date: November 22, 2012
    Applicant: MORESCO CORPORATION
    Inventors: Akinobu Wakabayashi, Haruo Kasai
  • 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: 20120107646
    Abstract: A magnetic recording disk has surface features of elevated lands and recessed grooves, and a planarized upper surface. A chemical-mechanical-polishing (CMP) stop layer is deposited over the lands and into the recesses. An adhesion film, like silicon, is deposited over the CMP stop layer, and fill material containing a silicon oxide (SiOx) is deposited over and in contact with the adhesion film. The adhesion film improves the adhesion of the SiOx fill material and prevents delamination during a subsequent two-step CMP planarizing process.
    Type: Application
    Filed: October 28, 2010
    Publication date: May 3, 2012
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
    Inventors: Vijay Prakash Singh Rawat, Kurt Allan Rubin
  • Patent number: 8168311
    Abstract: A magnetic recording disk with pre-patterned surface features of elevated lands and recessed grooves or trenches, like a discrete-track media (DTM) or bit-patterned media (BPM) disk, has a planarized surface. A multilayered disk overcoat is used to protect the recording layer, and at least one of the overcoat layers functions as a stop layer for terminating a chemical-mechanical polishing (CMP) process that substantially planarizes the disk. All of the layers of the multilayered overcoat are located above the lands, but none of the overcoat layers, or a number of layers less than the number of layers over the lands, is located above the recesses.
    Type: Grant
    Filed: April 2, 2010
    Date of Patent: May 1, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Charles Mathew Mate, Franck Dreyfus Rose, Kurt Allan Rubin, Steven Gary Schmid, Tushar Keshubhai Suther
  • Publication number: 20120008228
    Abstract: This invention provides a magnetic recording medium excellent in terms of corrosion resistance. The magnetic recording medium comprises a magnetic recording layer, a protective layer and a lubricant layer provided on a nonmagnetic substrate, and the lubricant layer comprises a compound having a heterocyclic ring.
    Type: Application
    Filed: July 8, 2011
    Publication date: January 12, 2012
    Inventors: Katsumi MABUCHI, Kyoko Honbo, Mina Amo
  • Patent number: 8043734
    Abstract: The invention relates to granular perpendicular magnetic recording media with a capping layer comprised of a material having high surface mobility and low surface energy. The capping layer surface is oxidized to produce a passivating surface that is impervious to corrosion.
    Type: Grant
    Filed: July 23, 2008
    Date of Patent: October 25, 2011
    Assignee: Seagate Technology LLC
    Inventors: Samuel Dacke Harkness, IV, Zhong Stella Wu
  • Patent number: 7943558
    Abstract: Lubricant with non-terminal functional groups. The location of the functional groups minimizes free chain length and molecular weight of a lubricant while simultaneously maximizing evaporation temperature. The locations of the functional groups to the backbone of the molecule of the lubricant allows for shorter lengths of free backbone length between functional groups attached to a lubricated surface. The lubricant lubricates mechanical devices including hard disk drives.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: May 17, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: John Martin Burns, Malika D. Carter, Xing-Cai Guo, Bruno Marchon, Robert Waltman
  • Publication number: 20110064970
    Abstract: A composite lubricant for recording disk media, a recording disk media including a layer of the composite lubricant, and method of manufacturing the same are described. The composite lubricant may include a non-phosphazene component and a phosphazene component where the non-phosphazene component is a difunctional perfluoropolyether compound terminated with first and second polar end groups, the first polar end group comprising a first number of hydroxyls and the second polar end includes a second number of hydroxyls, greater than the first number of hydroxyls. The phosphazene component may be a difunctional perfluoropolyether compound terminated with a phosphazene functional group and with a third polar end group, the third polar end group comprising a third number of hydroxyls equal to the second number of hydroxyls.
    Type: Application
    Filed: September 14, 2009
    Publication date: March 17, 2011
    Applicant: WD MEDIA, INC.
    Inventors: Shaun H. Chen, Yasuo Sakane, Henry S. Nishihira, Chi Kong Kwok, The V. Tran, Bing-Shiuan Chang
  • Publication number: 20110014498
    Abstract: This invention provides a magnetic disk which can satisfactorily suppress the elution of internal components from an end face of a magnetic disk, and corrosion damage. The magnetic disk comprises a disk substrate, and a thin film including a magnetic layer, a carbon-based protective layer, and a lubricating layer provided in that order on the disk substrate. The main surface and the end face of the magnetic disk are covered with the carbonaceous protective layer. The carbon-based protective layer contains nitrogen at a part adjacent to the lubricating layer. The content of nitrogen atoms relative to the content of carbon atoms in the protective layer formed on the end face is equal to or more than the content of nitrogen atoms relative to the content of carbon atoms in the protective layer formed on the main surface.
    Type: Application
    Filed: September 24, 2008
    Publication date: January 20, 2011
    Applicant: HOYA CORPORATION
    Inventors: Akira Shimada, Ito Nakamura
  • Publication number: 20100304186
    Abstract: Provided is a magnetic disk comprising a lubricating layer formed of a lubricant. The lubricant constituting the lubricating layer has excellent properties, for example, excellent fluidity, surface energy, and CFT properties. By virtue of the excellent properties, the magnetic disk has a high level of reliability despite a low flying height of a magnetic head due to a recent rapid increase in recording density and a very severe environment resistance requirement due to diversification of applications. The magnetic disk comprises a substrate and at least a magnetic layer, a protective layer, and a lubricating layer provided in that order over the substrate.
    Type: Application
    Filed: March 27, 2009
    Publication date: December 2, 2010
    Applicant: Hoya Corporation
    Inventor: Koichi Shimokawa
  • Publication number: 20100247969
    Abstract: Multiple anisotropy layered magnetic structures for controlling reversal mechanism and tightening of switching field distribution in bit patterned media are disclosed. The invention extends the exchange spring concept to more variable and sophisticated structures. Three or more layers with different anisotropy or anisotropy gradients increase writeability gains beyond the simple hard/soft bilayer exchange spring concept for BPM. The structures have a thin very hard, high anisotropy center layer that acts as a threshold or pinning layer for domain wall propagation through the entire media structure. In addition or alternatively, a thin very soft, low anisotropy center layer in between the commonly used soft surface layer and hard media layer allows quick initial propagation of the domain wall into the center of the media structure. Various properties of the media structures can be tuned more independently for optimization if using more advanced multi-anisotropy layer stacks.
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Thomas Hauet, Olav Hellwig, Manfred Ernst Schabes
  • Publication number: 20100173176
    Abstract: An apparatus includes a substrate, a recording layer on the substrate, and a nanocomposite layer on the recording layer, the nanocomposite layer including a wear-resistant material and a solid lubricant material, wherein the atomic percentage of the solid lubricant material in the nanocomposite layer is in a range from about 5% to about 99%. A method of making the apparatus is also provided.
    Type: Application
    Filed: January 5, 2009
    Publication date: July 8, 2010
    Applicant: Seagate Technology LLC
    Inventors: Lei Li, Yiao-Tee Hsia, Paul Max Jones, Earl Chrzaszcz Johns, James Dillion Kiely
  • Patent number: 7740961
    Abstract: A magnetic recording media has recording cells formed of two-dimensionally arrayed magnetic material, a nonmagnetic layer surrounding the recording cells, an adhesive film formed on each of the recording cells, and a lubricant directly adhered to the adhesive film.
    Type: Grant
    Filed: May 16, 2006
    Date of Patent: June 22, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroyuki Hieda, Naoko Kihara, Yoshitaka Yanagita
  • Publication number: 20100136371
    Abstract: A compound of the formula (I), and lubricant, and magnetic disk each using the same A-(CH2—Rf—CH2O—B—O)n—CH2—Rf—CH2-A??(I) wherein n is an integer of 1 to 4, A is a group of the formula (a) below, and B is a group of the formula (b) below, p being 1 or 2, R being C1-4 fluoroalkyl, Rf is —CF2O(CF2CF2O)x(CF2O)yCF2— or —CF2CF2O(CF2CF2CF2O)nCF2CF2—, x, y and z being each a real number of 0 to 50.
    Type: Application
    Filed: May 9, 2008
    Publication date: June 3, 2010
    Inventors: Tsuyoshi Shimizu, Kazunori Shirai, Nagayoshi Kobayashi
  • Publication number: 20100128378
    Abstract: A magnetic recording medium which does not easily cause a material containing Fe or Co to corrode is disclosed. The method for manufacturing a magnetic recording medium 122 includes a process of forming a magnetic layer 30 on a non-magnetic substrate 10, a process of forming a recessed area 65 in the magnetic layer 30, a process of forming a corrosion-resistant film 60 to cover an exposure surface 65c of the recessed area 65, and a process of forming a magnetic recording pattern made of the magnetically separated magnetic layer 30 by forming a non-magnetic layer 40 to fill in the recessed area 65.
    Type: Application
    Filed: October 27, 2009
    Publication date: May 27, 2010
    Applicant: SHOWA DENKO K.K.
    Inventors: Masato FUKUSHIMA, Shinichi Ishibashi, Akira Yamane
  • Patent number: 7683012
    Abstract: Lubricant with non-terminal functional groups. The location of the functional groups minimizes free chain length and molecular weight of a lubricant while simultaneously maximizing evaporation temperature. The locations of the functional groups to the backbone of the molecule of the lubricant allows for shorter lengths of free backbone length between functional groups attached to a lubricated surface. The lubricant lubricates mechanical devices including hard disk drives.
    Type: Grant
    Filed: September 12, 2005
    Date of Patent: March 23, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: John Martin Burns, Malika D. Carter, Xing-Cai Guo, Bruno Marchon, Robert Waltman
  • Patent number: 7501192
    Abstract: A first protection layer is overlaid on the surface of a recording layer in a recording medium. A second protection layer is overlaid on the surface of the recording layer at a position adjacent the first protection layer. The second protection layer has a composition different from that of the first protection layer. The first and second protection layers have different compositions, so that the overall protection layer is allowed to have an unequal property. The second protection layer may have a hardness higher than that of the first protection layer. A higher hardness of the second protection layer serves to avoid damages on the surface of the recording medium rather than the first protection layer. The recording medium can reliably be protected from collision or contact of an object.
    Type: Grant
    Filed: August 17, 2004
    Date of Patent: March 10, 2009
    Assignee: Fujitsu Limited
    Inventors: Takayuki Musashi, Yoshiharu Kasamatsu
  • Patent number: 7498091
    Abstract: First and second print layers extend on the surface of a medium body in a recording medium. The first print layer has a first thickness. The second print layer has a second thickness larger than the first thickness. A print protection layer covers over the first and second print layers on the surface of the medium body. An inclined surface is defined on the surface of the print protection layer. The inventors have found that a print layer has various thickness based on the kind of colors. The difference in the thickness causes a step on the surface of the print layer at the boundary between the different colors. The inclined surface is established on the surface of the print protection layer based on the step. A smooth relative movement can thus be realized between a head and the surface of the print protection layer.
    Type: Grant
    Filed: May 2, 2005
    Date of Patent: March 3, 2009
    Assignee: Fujitsu Limited
    Inventors: Tetsuo Hosokawa, Tomoyuki Aita
  • Publication number: 20080305365
    Abstract: A card-like magnetic recording medium comprising a non-magnetic substrate and a laminate containing a magnetic recording layer wherein the laminate is placed in at least a portion of the non-magnetic substrate; wherein the laminate comprises a light reflection quantity controlling layer, which includes a binder resin and at least one of a scale-like metal powder and fine flakes obtained from a metallic thin film and is formed on the magnetic recording layer, and further comprises a glistening coating layer which includes glistening particles and is formed on the light reflection quantity controlling layer; and the maximum reflectance of diffuse reflection light with respect to incident lights having a wavelength from 400 to 700 nm is 20 to 70% on a portion where the glistening coating layer is provided.
    Type: Application
    Filed: May 27, 2005
    Publication date: December 11, 2008
    Applicant: DAINIPPON INK AND CHEMICALS, INC.
    Inventors: Yoshikazu Yamazaki, Daisuke Yano
  • Publication number: 20080057348
    Abstract: A soft magnetic undercoat film, a first undercoat film, a second undercoat film, a perpendicular magnetic recording film, and a protective film are provided on a non-magnetic substrate, and the first undercoat film consists of Pt, Pd, or an alloy including at least one among these, and the second undercoat film consists of Ru or an Ru alloy.
    Type: Application
    Filed: January 14, 2004
    Publication date: March 6, 2008
    Inventors: Kenji Shimizu, Akira Sakawaki, Kazuo Kobayashi, Nguyen Tien Duong, Hiroshi Sakai, Takashi Hikosaka, Soichi Oikawa, Tomoyuki Maeda, Futoshi Nakamura
  • Publication number: 20070275270
    Abstract: An information medium which is capable of maintaining the protection capability by a lubricant for a long term. An information medium has a recording area and a non-recording area disposed on at least one surface of a disk-shaped base plate. The information medium is configured such that a lubricant exists on the one surface of the disk-shaped base plate. The recording area is configured such that a protective film formed of DLC exists above the recording layer. At least a surface-side portion of the non-recording area is formed of a resin material having a higher bonding ratio with respect to the lubricant than that of DLC.
    Type: Application
    Filed: May 24, 2007
    Publication date: November 29, 2007
    Applicant: TDK CORPORATION
    Inventors: Kazuhiro HATTORI, Kazuya SHIMAKAWA
  • 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
  • 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