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: 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: 20190304488
    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: Application
    Filed: March 28, 2019
    Publication date: October 3, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Eiki OZAWA, Takuto KUROKAWA
  • Publication number: 20190304498
    Abstract: The magnetic recording medium including: 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 methyl ethyl ketone cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the magnetic layer before methyl ethyl ketone 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: Eiki OZAWA, Takuto KUROKAWA
  • 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
  • Patent number: 10403318
    Abstract: A magnetic tape in which a thickness of a back coating layer is equal to or smaller than 0.20 ?m. 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 %. The 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 respectively greater than 0 nm and equal to or smaller than 10.0 nm. The difference between the spacing measured after performing the vacuum heating and a spacing measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.
    Type: Grant
    Filed: June 16, 2017
    Date of Patent: September 3, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Takuto Kurokawa, Eiki Ozawa, Norihito Kasada
  • Publication number: 20190027179
    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: Application
    Filed: July 17, 2018
    Publication date: January 24, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Eiki OZAWA, Norihito KASADA, Toshio TADA, Takuto KUROKAWA
  • Publication number: 20190027181
    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: Application
    Filed: July 18, 2018
    Publication date: January 24, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Eiki OZAWA, Toshio TADA, Norihito KASADA, Takuto KUROKAWA
  • Publication number: 20190027180
    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 hack coating layer is equal to or smaller than 0.060.
    Type: Application
    Filed: July 18, 2018
    Publication date: January 24, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Norihito Kasada, Toshio Tada, Eiki Ozawa, Takuto Kurokawa
  • Publication number: 20190027168
    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: Application
    Filed: July 18, 2018
    Publication date: January 24, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Norihito KASADA, Toshio TADA, Eiki OZAWA, Takuto KUROKAWA
  • Publication number: 20190027175
    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: Application
    Filed: July 18, 2018
    Publication date: January 24, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Takuto KUROKAWA, Norihito KASADA, Toshio TADA, Eiki OZAWA
  • Publication number: 20190027176
    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: Application
    Filed: July 17, 2018
    Publication date: January 24, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Takuto KUROKAWA, Norihito KASADA, Toshio TADA, Eiki OZAWA
  • Publication number: 20190027167
    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: Application
    Filed: July 18, 2018
    Publication date: January 24, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Toshio TADA, Norihito KASADA, Eiki OZAWA, Takuto KUROKAWA
  • Publication number: 20190027174
    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: Application
    Filed: July 17, 2018
    Publication date: January 24, 2019
    Applicant: FUJIFILM Corporation
    Inventors: Toshio TADA, Norihito KASADA, Eiki OZAWA, Takuto KUROKAWA
  • Publication number: 20180240494
    Abstract: The 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, in which a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, a contact angle with respect to 1-bromonaphthalene measured regarding the surface of the magnetic layer is 45.0° to 55.0°, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the back coating layer is equal to or smaller than 0.060.
    Type: Application
    Filed: February 20, 2018
    Publication date: August 23, 2018
    Applicant: FUJIFILM Corporation
    Inventors: Takuto KUROKAWA, Norihito KASADA
  • Publication number: 20180240490
    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 a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050, and a contact angle with respect to 1-bromonaphthalene measured regarding the surface of the magnetic layer is 45.0° to 55.0°.
    Type: Application
    Filed: February 20, 2018
    Publication date: August 23, 2018
    Applicant: FUJIFILM Corporation
    Inventors: Takuto KUROKAWA, Norihito KASADA
  • Publication number: 20170372741
    Abstract: Provided is a magnetic tape in which a thickness of a back coating layer is equal to or smaller than 0.20 ?m, 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 %, 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 respectively greater than 0 nm and equal to or smaller than 10.0 nm, and a difference between a spacing measured after performing the vacuum heating and a spacing measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.
    Type: Application
    Filed: June 16, 2017
    Publication date: December 28, 2017
    Applicant: FUJIFILM Corporation
    Inventors: Takuto KUROKAWA, Eiki OZAWA, Norihito KASADA
  • Publication number: 20170372739
    Abstract: Provided is a magnetic tape with the total thickness of a non-magnetic and magnetic layers is equal to or smaller than 0.60 ?m, a C—H derived C concentration calculated from a 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 equal to or greater than 45 atom %, 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 equal to or smaller than 7.0 nm, and a difference between a spacing measured after the vacuum heating and a spacing measured before the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.
    Type: Application
    Filed: June 16, 2017
    Publication date: December 28, 2017
    Applicant: FUJIFILM Corporation
    Inventors: Eiki OZAWA, Norihito KASADA, Takuto KUROKAWA