With Nonmagnetic Particles (e.g., Hematite Particles, Polystyrene, And Polyisoprene Copolymer, Etc.) Patents (Class 428/844)
  • Patent number: 11900977
    Abstract: A magnetic tape in which an arithmetic average roughness Ra measured at a surface of a magnetic layer with an atomic force microscope is 2.0 nm or less, and in an environment with a temperature of 32° C. and a relative humidity of 80%, a frictional force F45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: February 13, 2024
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11894033
    Abstract: A magnetic tape in which a vertical switching field distribution SFD of the magnetic tape is 1.5 or less, and in an environment with a temperature of 32° C. and a relative humidity of 80%, a frictional force F45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: February 6, 2024
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11894034
    Abstract: A magnetic tape in which an edge weave amount of a tape edge on at least one side of the magnetic tape is 1.5 ?m or less, and in an environment with a temperature of 32° C. and a relative humidity of 80%, a frictional force F45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: February 6, 2024
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11887637
    Abstract: A magnetic tape in which a C—H derived C concentration calculated from a C—H peak surface area ratio in C1s spectra obtained by X-ray photoelectron spectroscopy performed on a surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 atom % to 65 atom %, and in an environment with a temperature of 32° C. and a relative humidity of 80%, a frictional force F45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: January 30, 2024
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11869558
    Abstract: A magnetic tape in which a tape thickness of the magnetic tape is 5.2 ?m or less, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value45° of a surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 ?m to 50 ?m, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil prism is 30 ?m or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: January 9, 2024
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11869557
    Abstract: A magnetic tape in which an edge weave amount of a tape edge on at least one side of the magnetic tape is 1.5 ?m or less, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value45° of a surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 ?m to 50 ?m, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil prism is 30 ?m or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: January 9, 2024
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11869555
    Abstract: A magnetic tape in which a vertical switching field distribution SFD of the magnetic tape is 1.5 or less, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value45° of a surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 ?m to 50 ?m, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil prism is 30 ?m or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: January 9, 2024
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11869553
    Abstract: A magnetic tape in which an arithmetic average roughness Ra measured at a surface of the magnetic layer with an atomic force microscope is 2.0 nm or less, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value45° of a surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 ?m to 50 ?m, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil prism is 30 ?m or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: January 9, 2024
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11854586
    Abstract: A magnetic tape in which a C—H derived C concentration calculated from a C—H peak surface area ratio in C1s spectra obtained by XPS performed on a surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 atom % to 65 atom %, and in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value45° of the surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 ?m to 50 ?m, a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of given tilt angles of the AlFeSil prism is 30 ?m or less, and the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.
    Type: Grant
    Filed: September 28, 2022
    Date of Patent: December 26, 2023
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11551716
    Abstract: The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which an absolute value ?N of a difference between a refractive index Nxy measured regarding an in-plane direction of the magnetic layer and a refractive index Nz measured regarding a thickness direction of the magnetic layer is 0.25 to 0.40, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050.
    Type: Grant
    Filed: July 6, 2021
    Date of Patent: January 10, 2023
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11521650
    Abstract: A magnetic recording medium includes a layer structure including a magnetic layer, a base layer, and a back layer in this order, in which an average thickness tT is tT?5.5 ?m, a dimensional variation ?w in a width direction to tension change in a longitudinal direction is 660 ppm/N??w, and a surface roughness Rabe of the base layer on a side of the back layer is 4.2 nm?Rabe?8.5 nm.
    Type: Grant
    Filed: May 24, 2021
    Date of Patent: December 6, 2022
    Assignee: Sony Corporation
    Inventors: Minoru Yamaga, Noboru Sekiguchi
  • Patent number: 11508408
    Abstract: The magnetic tape in which a difference (S0.1?S1.6) between a spacing S0.1 and a spacing S1.6 obtained after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 32 nm. The S0.1 is a value obtained as a spacing under a pressing force of 0.1 atm from a relational expression between a pressure and a spacing obtained by performing a spacing measurement on the surface of the magnetic layer by an optical interference method under a pressing force of each of a plurality of different pressures after the n-hexane cleaning, and S1.6 is a spacing measured on the surface of the magnetic layer by the optical interference method under the pressing force of 1.6 atm after the n-hexane cleaning.
    Type: Grant
    Filed: January 28, 2021
    Date of Patent: November 22, 2022
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Naoki Sano, Norihito Kasada
  • Patent number: 11508407
    Abstract: A magnetic recording medium is a magnetic recording medium having a tape-like shape and includes a base substrate and a magnetic layer provided on the base substrate. A plurality of data tracks can be formed in the magnetic layer, a width of a data track is 2900 nm or less, and in a case of defining, as wmax and wmin, a maximum value and a minimum value respectively out of average values of a width of the magnetic recording medium measured under four kinds of environment in which temperature and relative humidity are set to (10° C., 10%), (10° C., 80%), (29° C., 80%), and (45° C., 10%), wmax and wmin satisfy a relation of (wmax?wmin)/wmin?400 [ppm].
    Type: Grant
    Filed: November 26, 2018
    Date of Patent: November 22, 2022
    Assignee: Sony Corporation
    Inventors: Noboru Sekiguchi, Minoru Yamaga
  • Patent number: 11468911
    Abstract: The magnetic tape includes a non-magnetic support; a non-magnetic layer including a non-magnetic powder and a binding agent on the non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic layer, in which a total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 ?m, an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5, the magnetic layer includes an oxide abrasive, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 ?m to 0.08 ?m.
    Type: Grant
    Filed: October 21, 2019
    Date of Patent: October 11, 2022
    Assignee: FUJIFILM Corporation
    Inventors: Takahiro Iwamoto, Norihito Kasada
  • Patent number: 11423933
    Abstract: The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which one or more kinds of component selected from the group consisting of a fatty acid and a fatty acid amide are included in a portion of the magnetic layer side on the non-magnetic support, and a C—H derived C concentration calculated from a C—H peak surface area ratio in C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on a surface of the magnetic layer at a photoelectron take-off angle of 10 degrees, after pressing the magnetic layer at a pressure of 70 atm is 45 atom % or more.
    Type: Grant
    Filed: September 16, 2020
    Date of Patent: August 23, 2022
    Assignee: FUJIFILM Corporation
    Inventors: Megumi Nakano, Eiki Ozawa, Norihito Kasada
  • Patent number: 11417359
    Abstract: The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder, in which an isoelectric point of a surface zeta potential of the magnetic layer after pressing the magnetic layer at a pressure of 70 atm is equal to or greater than 5.5.
    Type: Grant
    Filed: September 15, 2020
    Date of Patent: August 16, 2022
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Norihito Kasada
  • Patent number: 11367461
    Abstract: The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a difference Safter?Sbefore between a spacing Safter measured on a surface of the magnetic layer by optical interferometry after methyl-ethyl-ketone cleaning and a spacing Sbefore measured on the surface of the magnetic layer by optical interferometry before methyl-ethyl-ketone cleaning is more than 0 nm and 15.0 nm or less, and the non-magnetic support is an aromatic polyamide support having a moisture absorption of 2.2% or less.
    Type: Grant
    Filed: April 24, 2020
    Date of Patent: June 21, 2022
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 11315594
    Abstract: A magnetic recording medium is provided and includes a layer structure including a magnetic layer, a non-magnetic layer, and a base layer in this order, in which an average thickness tT of the magnetic recording medium is 3.5 ?m?tT?5.3 ?m, a dimensional variation ?w in a width direction of the magnetic recording medium to tension change in a longitudinal direction of the magnetic recording medium is 700 ppm/N??w?2000 ppm/N, and an average thickness tn of the non-magnetic layer is tn?1.0 ?m.
    Type: Grant
    Filed: September 25, 2020
    Date of Patent: April 26, 2022
    Assignee: Sony Corporation
    Inventors: Masaru Terakawa, Minoru Yamaga
  • Patent number: 11302353
    Abstract: In a magnetic recording medium, an average thickness tT is tT?5.5 ?m, a dimensional variation ?w in a width direction to tension change in a longitudinal direction is 650 ppm/N??w, and a rate of shrinkage in the longitudinal direction is 0.08% or less.
    Type: Grant
    Filed: September 11, 2020
    Date of Patent: April 12, 2022
    Assignee: Sony Corporation
    Inventors: Minoru Yamaga, Noboru Sekiguchi
  • Patent number: 11302354
    Abstract: The average thickness tT of a magnetic recording medium meets the requirement that tT?5.5 [?m], and the dimensional change amount ?w in the width direction of the magnetic recording medium with respect to the tension change in the longitudinal direction of the magnetic recording medium meets the requirement that 700 ppm/N??w.
    Type: Grant
    Filed: September 25, 2020
    Date of Patent: April 12, 2022
    Assignee: Sony Corporation
    Inventors: Noboru Sekiguchi, Minoru Yamaga
  • Patent number: 11211087
    Abstract: The magnetic tape includes a non-magnetic support; a magnetic layer including a ferromagnetic powder and a binding agent on one surface of the non-magnetic support; and a back coating layer including a non-magnetic powder and a binding agent on the other surface of the non-magnetic support, in which a center line average surface roughness Ra measured regarding a surface of the back coating layer is equal to or smaller than 7.0 nm, and a difference between a spacing Safter measured by optical interferometry regarding the surface of the back coating layer after methyl ethyl ketone cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the back coating layer before methyl ethyl ketone cleaning is greater than 0 nm and equal to or smaller than 30.0 nm.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: December 28, 2021
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Takuto Kurokawa
  • Patent number: 11062732
    Abstract: The magnetic tape includes a non-magnetic support; a magnetic layer including a ferromagnetic powder and a binding agent on one surface of the non-magnetic support; and a back coating layer including a non-magnetic powder and a binding agent on the other surface of the non-magnetic support, in which a center line average surface roughness Ra measured regarding a surface of the back coating layer is equal to or smaller than 7.0 nm, and a difference between a spacing Safter measured by optical interferometry regarding the surface of the back coating layer after methyl ethyl ketone cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the back coating layer before methyl ethyl ketone cleaning is greater than 0 nm and equal to or smaller than 30.0 nm.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: July 13, 2021
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Takuto Kurokawa
  • Patent number: 10910009
    Abstract: The magnetic tape has a magnetic layer containing ferromagnetic powder and binder on a nonmagnetic support, wherein the centerline average surface roughness Ra as measured on the surface on the magnetic layer side of the magnetic tape is less than or equal to 1.8 nm, and the logarithmic decrement as determined by a pendulum viscoelasticity test on the surface on the magnetic layer side of the magnetic tape is less than or equal to 0.050.
    Type: Grant
    Filed: June 19, 2018
    Date of Patent: February 2, 2021
    Assignee: FUJIFILM Corporation
    Inventors: Masahito Oyanagi, Norihito Kasada, Toshio Tada, Takuro Sugiyama
  • Patent number: 10854229
    Abstract: Provided is a magnetic tape in which an Ra measured regarding a surface of a magnetic layer is equal to or smaller than 1.8 nm, Int(110)/Int(114) of a hexagonal ferrite crystal structure obtained by an XRD analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, full widths at half maximum of spacing distribution measured by optical interferometry regarding the surface of the back coating layer before and after performing a vacuum heating with respect to the magnetic tape are greater than 0 nm and equal to or smaller than 10.0 nm, and a difference between the spacings measured by optical interferometry regarding the surface of the back coating layer before and after performing the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.
    Type: Grant
    Filed: July 18, 2018
    Date of Patent: December 1, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Toshio Tada, Norihito Kasada, Takuto Kurokawa
  • Patent number: 10854226
    Abstract: Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which the magnetic layer has a timing-based servo pattern, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, and a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, and a magnetic tape device including this magnetic tape.
    Type: Grant
    Filed: July 18, 2018
    Date of Patent: December 1, 2020
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 10854233
    Abstract: Provided are a magnetic recording medium, in which a magnetic layer includes a ferromagnetic hexagonal ferrite powder, a binding agent, an oxide abrasive, an intensity ratio Int(110)/Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio is 0.65 to 1.00, one or more kinds of component selected from the group consisting of fatty acid and fatty acid amide is contained in a magnetic layer side portion on the non-magnetic support, a C—H derived C concentration of the magnetic layer is 45 atom % to 65 atom %, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 ?m to 0.08 ?m, and a magnetic recording and reproducing device including this magnetic recording medium.
    Type: Grant
    Filed: September 27, 2018
    Date of Patent: December 1, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Norihito Kasada
  • Patent number: 10854231
    Abstract: Provided are a magnetic recording medium, in which a magnetic layer includes ferromagnetic hexagonal ferrite powder, a binding agent, and an oxide abrasive, an intensity ratio Int(110)/Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00, a coefficient of friction measured regarding a base portion of a surface of the magnetic layer is equal to or smaller than 0.30, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 ?m to 0.08 ?m, and a magnetic recording and reproducing device including this magnetic recording medium.
    Type: Grant
    Filed: September 26, 2018
    Date of Patent: December 1, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa
  • Patent number: 10854227
    Abstract: The magnetic recording medium includes a non-magnetic support and a magnetic layer which contains ferromagnetic powder and a binder, in which the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the magnetic layer contains an abrasive, Int (110)/Int (114) of a crystal structure of the hexagonal ferrite, determined by performing X-ray diffraction analysis on the magnetic layer by using an In-Plane method, to a peak intensity of a diffraction peak of (114) plane of the crystal structure is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, and a logarithmic decrement obtained by performing a pendulum viscoelasticity test on a surface of the magnetic layer is equal to or lower than 0.050.
    Type: Grant
    Filed: July 18, 2018
    Date of Patent: December 1, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Toshio Tada, Eiki Ozawa, Takuto Kurokawa
  • Patent number: 10854230
    Abstract: The magnetic tape includes a magnetic layer including ferromagnetic powder, non-magnetic powder, and a binding agent and a back coating layer including non-magnetic powder and a binding agent, in which the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, an Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the back coating layer is equal to or smaller than 0.060.
    Type: Grant
    Filed: July 18, 2018
    Date of Patent: December 1, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Toshio Tada, Eiki Ozawa, Takuto Kurokawa
  • Patent number: 10854232
    Abstract: The magnetic recording medium includes a magnetic layer which contains ferromagnetic hexagonal ferrite powder and a binder, in which the magnetic layer contains an abrasive and a fatty acid ester, Int (110)/Int (114) of a crystal structure of the hexagonal ferrite, determined by performing XRD analysis on the magnetic layer by using an In-Plane method, is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, FWHMbefore and FWHMafter is greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between spacings measured within a surface of the magnetic layer by an optical interference method before and after the heating in a vacuum is greater than 0 nm and equal to or smaller than 8.0 nm.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: December 1, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Norihito Kasada, Toshio Tada, Takuto Kurokawa
  • Patent number: 10854234
    Abstract: Provided are a magnetic recording medium, in which a magnetic layer includes ferromagnetic hexagonal ferrite powder, a binding agent, and an oxide abrasive, an intensity ratio Int(110)/Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding a surface of the magnetic layer is equal to or smaller than 0.050, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 ?m to 0.08 ?m, and a magnetic recording and reproducing device including this magnetic recording medium.
    Type: Grant
    Filed: September 27, 2018
    Date of Patent: December 1, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa
  • Patent number: 10839851
    Abstract: The magnetic recording medium includes a magnetic layer containing ferromagnetic powder and a binder, in which the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the magnetic layer contains an abrasive, an intensity ratio of a peak intensity of a diffraction peak of (110) plane of a crystal structure of the hexagonal ferrite, determined by performing X-ray diffraction analysis on the magnetic layer by using an In-Plane method, to a peak intensity of a diffraction peak of (114) plane of the crystal structure is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, and a coefficient of friction measured in a base material portion within a surface of the magnetic layer is equal to or lower than 0.30.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: November 17, 2020
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 10839849
    Abstract: The magnetic recording medium includes a non-magnetic support and a magnetic layer, wherein the magnetic layer contains ferromagnetic hexagonal ferrite powder and an abrasive, Int (110)/Int (114) of a crystal structure of the hexagonal ferrite determined by performing XRD analysis on the magnetic layer by using an In-Plane method is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, one or more kinds of components selected from the group consisting of a fatty acid and a fatty acid amide is contained in a magnetic layer side portion on the support, and a C—H-derived C concentration obtained by ESCA within a surface of the magnetic layer at a photoelectron take-off angle of 10° is equal to or higher than 45 at %.
    Type: Grant
    Filed: July 18, 2018
    Date of Patent: November 17, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Toshio Tada, Norihito Kasada, Eiki Ozawa, Takuto Kurokawa
  • Patent number: 10839850
    Abstract: Provided is a magnetic tape in which an Ra measured regarding a surface of a magnetic layer is equal to or smaller than 1.8 nm, Int(110)/Int(114) of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, the back coating layer includes one or more kinds of component selected from the group consisting of fatty acid and fatty acid amide, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the back coating layer at a photoelectron take-off angle of 10 degrees is equal to or greater than 35 atom %.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: November 17, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Toshio Tada, Norihito Kasada, Eiki Ozawa, Takuto Kurokawa
  • Patent number: 10714139
    Abstract: The magnetic recording medium includes a non-magnetic support and a magnetic layer containing ferromagnetic powder and a binder, in which the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the magnetic layer contains an abrasive, an intensity ratio of a peak intensity of a diffraction peak of (110) plane of a crystal structure of the hexagonal ferrite, determined by performing X-ray diffraction analysis on the magnetic layer by using an In-Plane method, to a peak intensity of a diffraction peak of (114) plane of the crystal structure is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, and a contact angle with 1-bromonaphthalene measured within a surface of the magnetic layer is in a range of 50.0° to 55.0°.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: July 14, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Norihito Kasada, Toshio Tada, Eiki Ozawa
  • Patent number: 10522180
    Abstract: The magnetic tape has a nonmagnetic layer containing nonmagnetic powder and binder on a nonmagnetic support, and a magnetic layer containing ferromagnetic powder and binder on the nonmagnetic layer; wherein the combined thickness of the nonmagnetic layer and the magnetic layer is less than or equal to 0.60 ?m, the coefficient of friction as measured on the base portion of the surface of the magnetic layer is less than or equal to 0.35, at least the magnetic layer contains one or more components selected from the group consisting of a fatty acid and a fatty acid amide, and a C—H derived carbon, C, concentration calculated from a C—H peak area ratio in a C1s spectrum obtained by X-ray photoelectron spectroscopy conducted at a photoelectron take-off angle of 10 degrees on the surface of the magnetic layer is greater than or equal to 45 atom %.
    Type: Grant
    Filed: December 15, 2016
    Date of Patent: December 31, 2019
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 10438624
    Abstract: A magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support. The center line average surface roughness Ra measured regarding the surface of the magnetic layer is less than or equal to 1.8 nm. The logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is less than or equal to 0.050. The ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the magnetic layer includes an abrasive, and the tilt cos ? of the ferromagnetic hexagonal ferrite powder with respect to the surface of the magnetic layer acquired by cross section observation performed using a scanning transmission electron microscope is 0.85 to 1.00.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: October 8, 2019
    Assignee: FUJIFILM Corporation
    Inventor: Norihito Kasada
  • Patent number: 9805754
    Abstract: A magnetic recording medium includes: a substrate; and a magnetic layer including a ferrimagnetic particle powder. A product (V×SFD) of a particle volume V and a holding force distribution SFD of the ferrimagnetic particle is equal to or less than 2500 nm3.
    Type: Grant
    Filed: July 17, 2014
    Date of Patent: October 31, 2017
    Assignee: Sony Corporation
    Inventor: Katsunori Maeshima
  • Publication number: 20140287271
    Abstract: The magnetic recording medium comprises protrusions on a surface of a magnetic layer such that when protrusions of equal to or more than 8 nm in height as measured by AFM on the surface of the magnetic layer are divided into protrusions A formed of a spherical material and protrusions B formed of a non-spherical material, a value a, obtained by adding three times a standard deviation ? of heights of protrusions A to an average value of the heights of protrusions A, a value b, obtained by adding three times a standard deviation ? of heights of protrusions B to an average value of the heights of protrusions B, and a difference c, obtained by subtracting b from a, are calculated, conditions 13 nm?a?25 nm, 13 nm?b?25 nm, and 0.0 nm?c?10 nm are satisfied.
    Type: Application
    Filed: March 21, 2014
    Publication date: September 25, 2014
    Applicant: FUJIFILM Corporation
    Inventor: Masahide SATO
  • Patent number: 8623529
    Abstract: An object of the present invention is to provide 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. In a typical structure of the present invention, a method of manufacturing a perpendicular magnetic recording medium 100 including a magnetic recording layer 122, a medium protective layer 126, and a lubricating layer 128 in this order on a base 110 includes: 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: Grant
    Filed: March 24, 2009
    Date of Patent: January 7, 2014
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventor: Kouta Suzuki
  • Patent number: 8535817
    Abstract: An aspect of the present invention relates to a magnetic recording medium comprising a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein the magnetic layer comprises a nonmagnetic powder of which coefficient of variation CV of a particle size distribution as denoted by the following formula (1): CV(%)=?/?×100??(1) is less than 20 percent, and the magnetic layer has a thickness being equal to or less than 0.1 ?m and falling within a range of 1.1??/t?8.0, wherein ? denotes a standard deviation of a particle diameter, ? denotes an average particle diameter of the nonmagnetic powder comprised in the magnetic layer being expressed in ?m, and t denotes a thickness of the magnetic layer being expressed in ?m.
    Type: Grant
    Filed: August 26, 2010
    Date of Patent: September 17, 2013
    Assignee: FUJIFILM Corporation
    Inventor: Noriko Imaoka
  • Publication number: 20120196156
    Abstract: An aspect of the present invention relates to a magnetic tape comprising, on one surface of a nonmagnetic support, a nonmagnetic layer containing a nonmagnetic powder and a binder, and thereon, a magnetic layer containing a ferromagnetic powder and a binder, wherein the magnetic layer contains a nonmagnetic filler the average particle diameter ? of which satisfies relation (I) below with a thickness t of the magnetic layer: 1.0??/t?2.0??(I); the thickness t of the magnetic layer ranges from 30 to 200 nm; the nonmagnetic layer has a thickness ranging from 30 to 200 nm; a composite elastic modulus as measured on a surface of the magnetic layer ranges from 6.0 to 8.0 GPa; and a centerline average surface roughness Ra of the surface of the magnetic layer, as measured by an optical three-dimensional profilometer, ranges from 0.2 to 1.5 nm.
    Type: Application
    Filed: January 26, 2012
    Publication date: August 2, 2012
    Applicant: FUJIFILM CORPORATION
    Inventor: Ryota SUZUKI
  • Patent number: 8124256
    Abstract: A magnetic recording medium with excellent high density recording performances and good durability comprising a non-magnetic substrate, a non-magnetic layer containing a non-magnetic powder and a binder formed on the non-magnetic substrate, and a magnetic layer having a thickness of less than 100 nm and containing a substantially particulate non-magnetic powder, a substantially particulate magnetic powder having an average particle size of less than 25 nm, and a binder, wherein an average particle size R of the non-magnetic powder contained in the magnetic layer and a thickness D of the magnetic powder satisfy the following relationship: 0.88?R/D?2.5.
    Type: Grant
    Filed: August 11, 2005
    Date of Patent: February 28, 2012
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Sadamu Kuse, Kazuhiko Nakiri
  • Patent number: 7901805
    Abstract: A magnetic recording medium, which comprises: a nonmagnetic support; and a magnetic layer comprising a ferromagnetic powder and a binder, wherein an average surface roughness (Ra) at a center of a surface of the magnetic layer measured by using an atomic force microscope (AFM) is 2 nm or less, the maximum height (Rmax) thereof is 50 nm or less, and an arithmetic average of phase difference between a drive signal and a response signal of a probe measured with the atomic force microscope in a tapping mode is from 2 to 20°, and a method of producing the same.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: March 8, 2011
    Assignee: FUJIFILM Corporation
    Inventor: Koji Naoe
  • Patent number: 7517598
    Abstract: A magnetic recording medium having a non-magnetic support and a magnetic layer formed thereon, wherein the magnetic layer comprises a ferromagnetic powder, a binder and a non-magnetic inorganic powder, and wherein at least 95% of the non-magnetic powder particles contained in the magnetic layer have a particle size of 0.05 to 0.013 ?m, provide that the non-magnetic powder particles are those found in a field of view of 1.8 ?m×2.4 ?m when the surface of the magnetic layer is observed with a scanning electron microscope at a magnification of 50,000 times.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: April 14, 2009
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Ken Yoshimura, Tetsutaro Inoue
  • Patent number: 7378679
    Abstract: A patterned substrate includes a laminated pattern having laminated patterns that are formed by drying droplets containing a pattern formation material. A lower layer pattern contains lyophilic microparticles that are lyophilic with respect to droplets that form an upper layer pattern.
    Type: Grant
    Filed: December 12, 2005
    Date of Patent: May 27, 2008
    Assignee: Seiko Epson Corporation
    Inventor: Naoyuki Toyoda
  • Patent number: 7368188
    Abstract: A magnetic recording medium including a polymer support having thereon at least one magnetic layer containing a ferromagnetic metal powder having an average major axis length of from 20 to 100 nm or a ferromagnetic hexagonal ferrite powder having an average tabular diameter of from 5 to 40 nm and a binder, the polymer support having an intrinsic viscosity of from 0.47 to 0.51 dL/g, a Young's modulus in the machine direction of from 7.0 to 8.6 GPa, a Young's modulus in the transverse direction of from 5.4 to 8.0 GPa, and a breaking strength in the transverse direction of from 370 to 450 MPa.
    Type: Grant
    Filed: January 19, 2005
    Date of Patent: May 6, 2008
    Assignee: FUJIFILM Corporation
    Inventors: Katsuhiko Meguro, Masatoshi Takahashi
  • Patent number: 7357980
    Abstract: A nonmagnetic powder, used for the nonmagnetic layer of a coated type magnetic recording medium having a multilayer structure, has good dispersibility in the binder in which it is dispersed to prepare a coating material that is applied to the nonmagnetic layer. The nonmagnetic powder has an iron compound as its principal component and exhibits a maximum pore volume value in a pore diameter range of 0.01 ?m to 0.05 ?m within a pore diameter range of 0.0018 ?m to 0.1 ?m in which the relationship between pore diameter and pore volume is calculated by a mercury injection method. The nonmagnetic powder exhibits a cumulative pore volume value in a pore diameter range of 0.0018 ?m to 0.01 ?m that is not more than 30% of the cumulative pore volume value in the pore diameter range of 0.0018 ?m to 0.1 ?m.
    Type: Grant
    Filed: August 19, 2005
    Date of Patent: April 15, 2008
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Shinichi Konno, Kenichi Inoue, Toshihiko Ueyama, Ken Inoue
  • Publication number: 20070224459
    Abstract: A magnetic recording medium including a substrate having a front side and a backside, having at least a magnetic recording layer coating the front side, and possibly an optional support layer or sublayer, wherein at least one layer of the magnetic recording medium includes carbon nanotubes.
    Type: Application
    Filed: March 24, 2006
    Publication date: September 27, 2007
    Inventors: Meng C. Hsieh, Andrei Potanin
  • Patent number: 7186472
    Abstract: A magnetic recording medium comprising a support and a magnetic layer containing an abrasive, a binder and ferromagnetic powder dispersed in the binder, wherein the magnetic layer has a thickness of from 20 to 500 nm, the abrasive has a Mohs' hardness of 5 or more and a relative abrasive velocity of less than 200, and value A of a relational expression A=K/Z of an average particle size K of the abrasive and the thickness Z of the magnetic layer is from 0.1 to 3.0.
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: March 6, 2007
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Noboru Zinbo