Patents by Inventor Takuto KUROKAWA

Takuto KUROKAWA has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10861491
    Abstract: The magnetic tape has a magnetic layer containing ferromagnetic powder, abrasive, and binder on a nonmagnetic support, wherein the centerline average surface roughness Ra measured on the surface of the magnetic layer is less than or equal to 1.8 nm, the contact angle for 1-bromonaphthalene that is measured on the surface of the magnetic layer falls within a range of 45.0° to 60.0°, and the coefficient of friction that is measured on the base portion of the surface of the magnetic layer is less than or equal to 0.35.
    Type: Grant
    Filed: February 27, 2017
    Date of Patent: December 8, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Masahito Oyanagi, Norihito Kasada, 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: 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: 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: 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: 10854228
    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, a center line average surface roughness 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 contact angle with respect to 1-bromonaphthalene measured regarding a surface of the back coating layer is 15.0° to 30.0°.
    Type: Grant
    Filed: July 18, 2018
    Date of Patent: December 1, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Norihito Kasada, Toshio Tada, Eiki Ozawa
  • 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: 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
  • Publication number: 20200279580
    Abstract: The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a difference (S0.5?S13.5) between a spacing S0.5 measured on a surface of the magnetic layer by optical interferometry after n-hexane cleaning under a pressure of 0.5 atm and a spacing S13.5 measured on the surface of the magnetic layer by optical interferometry after n-hexane cleaning under a pressure of 13.5 atm is 9.0 nm or more.
    Type: Application
    Filed: February 27, 2020
    Publication date: September 3, 2020
    Applicant: FUJIFILM Corporation
    Inventors: Naoki SANO, Eiki OZAWA, Norihito KASADA, Takuto KUROKAWA
  • Patent number: 10741208
    Abstract: The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which a center line average surface roughness Ra measured regarding a surface of the magnetic layer is 1.0 nm to 1.6 nm, and a difference (Safter?Sbefore) between a spacing Safter measured by optical interferometry regarding the surface of the magnetic layer after ethanol cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the magnetic layer before ethanol cleaning is greater than 0 nm and equal to or smaller than 6.0 nm.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: August 11, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Eiki Ozawa
  • Publication number: 20200227081
    Abstract: Provided are a magnetic tape comprising a magnetic layer containing a ferromagnetic powder and a binding agent on a non-magnetic support, in which the magnetic layer contains an oxide abrasive, an average particle diameter of the oxide abrasive obtained from a secondary ion image acquired by irradiating a surface of the magnetic layer with a focused ion beam is greater than 0.08 ?m and 0.14 ?m or smaller, and an absolute value ?N of a difference between a refractive index Nxy measured with respect to an in-plane direction of the magnetic layer and a refractive index Nz measured with respect to a thickness direction of the magnetic layer is 0.25 to 0.40, and a magnetic recording and reproducing device including the magnetic tape.
    Type: Application
    Filed: March 27, 2020
    Publication date: July 16, 2020
    Applicant: FUJIFILM Corporation
    Inventors: Hidemasa HOSODA, Takuto KUROKAWA, Norihito KASADA, Takahiro IWAMOTO
  • Publication number: 20200227084
    Abstract: Provided are a magnetic tape comprising a magnetic layer containing a ferromagnetic powder and a binding agent on a non-magnetic support, in which the magnetic layer contains an oxide abrasive, an average particle diameter of the oxide abrasive obtained from a secondary ion image acquired by irradiating a surface of the magnetic layer with a focused ion beam is 0.04 ?m to 0.08 ?m, and an absolute value ?N of a difference between a refractive index Nxy measured with respect to an in-plane direction of the magnetic layer and a refractive index Nz measured with respect to a thickness direction of the magnetic layer is 0.25 to 0.40, and a magnetic recording and reproducing device including the magnetic tape.
    Type: Application
    Filed: March 27, 2020
    Publication date: July 16, 2020
    Applicant: FUJIFILM Corporation
    Inventors: Takahiro IWAMOTO, Hidemasa Hosoda, Norihito Kasada, 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: 10679657
    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 (Safter?Sbefore) between a spacing Safter measured by optical interferometry regarding the surface of the back coating layer after ethanol cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the back coating layer before ethanol cleaning is greater than 0 nm and equal to or smaller than 15.0 nm.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: June 9, 2020
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Eiki Ozawa
  • Publication number: 20200090694
    Abstract: The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which a difference (S0.5?S13.5) between a spacing S0.5 measured by optical interferometry regarding a surface of the magnetic layer under a pressing force of 0.5 atm after n-hexane cleaning and a spacing S13.5 measured by optical interferometry regarding the surface of the magnetic layer under a pressing force of 13.5 atm after n-hexane cleaning is equal to or smaller than 3.0 nm, and a magnetic recording and reproducing device including this magnetic recording medium.
    Type: Application
    Filed: September 12, 2019
    Publication date: March 19, 2020
    Applicant: FUJIFILM Corporation
    Inventors: Naoki SANO, Takuto Kurokawa, Norihito Kasada, Eiki Ozawa
  • Patent number: 10497388
    Abstract: A magnetic tape is provided having a total thickness of the non-magnetic and magnetic layers of less than or equal to 0.60 ?m. The C—H derived C concentration calculated from the C—H peak area ratio of C1s spectra by ESCA on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is greater than or equal to 45 atom %. The full widths at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before and after vacuum heating with respect to the magnetic tape are respectively greater than 0 nm and less than or equal to 7.0 nm, and the difference between a spacing measured after the vacuum heating and a spacing measured before the vacuum heating is greater than 0 nm and less than or equal to 8.0 nm.
    Type: Grant
    Filed: June 16, 2017
    Date of Patent: December 3, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Norihito Kasada, Takuto Kurokawa
  • Patent number: 10475480
    Abstract: A magnetic tape includes a non-magnetic support; a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support. The center line average surface roughness Ra measured regarding a surface of the magnetic layer is less than or equal to 1.8 nm. The contact angle with respect to 1-bromonaphthalene measured regarding the surface of the magnetic layer is 45.0° to 55.0°. Also, the logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the back coating layer is less than or equal to 0.060.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: November 12, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Norihito Kasada
  • Patent number: 10453488
    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, and the contact angle with respect to 1-bromonaphthalene measured regarding the surface of the magnetic layer is 45.0° to 55.0°.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: October 22, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Norihito Kasada
  • Publication number: 20190304499
    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 (Safter?Sbefore) between a spacing Safter measured by optical interferometry regarding the surface of the back coating layer after ethanol cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the back coating layer before ethanol cleaning is greater than 0 nm and equal to or smaller than 15.0 nm.
    Type: Application
    Filed: March 28, 2019
    Publication date: October 3, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Takuto KUROKAWA, Eiki OZAWA
  • Publication number: 20190304497
    Abstract: The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which a center line average surface roughness Ra measured regarding a surface of the magnetic layer is 1.0 nm to 1.6 nm, and a difference (Safter?Sbefore) between a spacing Safter measured by optical interferometry regarding the surface of the magnetic layer after ethanol cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the magnetic layer before ethanol cleaning is greater than 0 nm and equal to or smaller than 6.0 nm.
    Type: Application
    Filed: March 28, 2019
    Publication date: October 3, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Takuto KUROKAWA, Eiki OZAWA