公开(公告)号：US20190027168A1

公开(公告)日：2019-01-24

申请号：US16038687

申请日：2018-07-18

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA ,  Toshio TADA ,  Eiki OZAWA ,  Takuto KUROKAWA

IPC: G11B5/008 ,  G11B5/78 ,  G11B5/706 ,  G11B5/712 ,  G11B5/708

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.

公开(公告)号：US20190027167A1

公开(公告)日：2019-01-24

申请号：US16038669

申请日：2018-07-18

Applicant: FUJIFILM Corporation

Inventor： Toshio TADA ,  Norihito KASADA ,  Eiki OZAWA ,  Takuto KUROKAWA

IPC: G11B5/008 ,  G11B5/78 ,  G11B5/706 ,  G11B5/712 ,  G11B5/708 ,  G11B5/84

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 %.

公开(公告)号：US20180240494A1

公开(公告)日：2018-08-23

申请号：US15900242

申请日：2018-02-20

Applicant: FUJIFILM Corporation

Inventor： Takuto KUROKAWA ,  Norihito KASADA

IPC: G11B5/712 ,  G11B5/008 ,  G11B5/706

CPC classification number: G11B5/712 ,  G11B5/00813 ,  G11B5/70 ,  G11B5/702 ,  G11B5/70615 ,  G11B5/71 ,  G11B5/735 ,  G11B5/78

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.

公开(公告)号：US20170372739A1

公开(公告)日：2017-12-28

申请号：US15624792

申请日：2017-06-16

Applicant: FUJIFILM Corporation

Inventor： Eiki OZAWA ,  Norihito KASADA ,  Takuto KUROKAWA

IPC: G11B5/78 ,  G11B5/71 ,  G11B5/712 ,  G11B5/73

CPC classification number: G11B5/78 ,  G11B5/00817 ,  G11B5/70 ,  G11B5/708 ,  G11B5/71 ,  G11B5/712 ,  G11B5/7305

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 μm, 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.

公开(公告)号：US20170249963A1

公开(公告)日：2017-08-31

申请号：US15443026

申请日：2017-02-27

Applicant: FUJIFILM Corporation

Inventor： Masahito OYANAGI ,  Norihito KASADA ,  Takuto KUROKAWA

IPC: G11B5/71 ,  G11B5/735 ,  G11B5/733 ,  G11B5/78 ,  G11B5/73

CPC classification number: G11B5/71 ,  G11B5/702 ,  G11B5/7085 ,  G11B5/7305 ,  G11B5/733 ,  G11B5/735 ,  G11B5/78

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.