公开(公告)号：US20240321309A1

公开(公告)日：2024-09-26

申请号：US18680257

申请日：2024-05-31

申请人： FUJIFILM Corporation

发明人： Norihito KASADA

IPC分类号： G11B5/706 ,  G11B5/708 ,  G11B5/714 ,  G11B5/735 ,  G11B5/78

CPC分类号： G11B5/70678 ,  G11B5/7085 ,  G11B5/714 ,  G11B5/7356 ,  G11B5/78

摘要： Provided is a magnetic tape, in which, 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, which is measured at a tilt angle of 45° of an AlFeSil square bar, is 20 μm or more and 50 μm or less, and standard deviation of AlFeSil abrasion values of the surface of the magnetic layer, which are respectively measured at tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil square bar, is 30 μm or less. The tilt angle of the AlFeSil square bar is an angle formed by a longitudinal direction of the AlFeSil square bar and a width direction of the magnetic tape. The magnetic tape includes a polyethylene naphthalate support having a Young's modulus in a width direction of 10000 MPa or more.

公开(公告)号：US20240321303A1

公开(公告)日：2024-09-26

申请号：US18680013

申请日：2024-05-31

申请人： FUJIFILM Corporation

发明人： Norihito KASADA

IPC分类号： G11B5/592 ,  G11B5/706 ,  G11B5/735 ,  G11B5/78 ,  G11B15/43

CPC分类号： G11B5/5928 ,  G11B5/70678 ,  G11B5/7356 ,  G11B5/78 ,  G11B15/43

摘要： Provided is a magnetic tape apparatus. In a case where a maximum value of an absolute value of a difference between a servo band interval obtained before the following storage and a servo band interval obtained after the storage of N cycles, in which a predetermined storage is set as one cycle, is denoted by A, and a medium life is equal to or longer than 5 years, which is calculated by a linear function of A and a logarithm logeT of T derived from a value of A and a value of the logarithm logeT of a total storage time T of the storage of the N cycles, each of which is obtained by setting N as 1, 2, 3, 4, or 5. The medium life is T, in a case where A satisfies Expression a: A=1.5−B+C.

公开(公告)号：US12057152B2

公开(公告)日：2024-08-06

申请号：US17186470

申请日：2021-02-26

申请人： FUJIFILM Corporation

发明人： Noriko Oyanagi ,  Wataru Kikuchi

IPC分类号： G11B5/008 ,  C10M105/54 ,  C10M107/38 ,  C10M171/00 ,  G11B5/706 ,  G11B5/73 ,  G11B5/735

CPC分类号： G11B5/73935 ,  G11B5/00813 ,  G11B5/70678 ,  G11B5/7358

摘要： The magnetic recording medium includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. An anisotropic magnetic field Hk is 12 kOe or more, a center line average roughness Ra of the surface of the magnetic recording medium on the magnetic layer side is 1.2 nm or less, and a ratio θr of a contact angle θ2 with respect to 1-bromonaphthalene, measured on a surface on the magnetic layer side after a 1,1,1,2,2,3,4,5,5,5-decafluoropentane immersion, to a contact angle θ1 with respect to 1-bromonaphthalene, measured on the surface on the magnetic layer side before the 1,1,1,2,2,3,4,5,5,5-decafluoropentane immersion is 0.95 or less.

公开(公告)号：US20240170013A1

公开(公告)日：2024-05-23

申请号：US18284420

申请日：2022-02-08

申请人： Sony Group Corporation

发明人： Minoru YAMAGA ,  Futoshi SASAKI

IPC分类号： G11B5/706 ,  G11B5/714 ,  G11B5/78 ,  G11B23/037

CPC分类号： G11B5/70626 ,  G11B5/714 ,  G11B5/78 ,  G11B23/037

摘要： An object is to provide a magnetic recording medium, in which occurrence of friction rise according to several times of running is low, capable of appropriately maintaining abrasivity of a magnetic head by adjusting heights of protrusions formed in accordance with first particles having conductivity and second particles of which Mohs hardness is 7 or more.
The present technology provides a magnetic recording medium including a magnetic layer containing magnetic powders, in which, the magnetic layer contains first particles having conductivity and second particles of which Mohs hardness is 7 or more, protrusions are formed on a surface of the magnetic layer side in accordance with the first particles and the second particles, a ratio (H1/H2) of an average height (H1) of protrusions formed in accordance with the first particles to an average height (H2) of protrusions formed in accordance with the second particles is 2.3 or less, and the average height (H2) of the protrusions formed in accordance with the second particles is 7 nm or less.

公开(公告)号：US20240105224A1

公开(公告)日：2024-03-28

申请号：US18517870

申请日：2023-11-22

申请人： FUJIFILM Corporation

发明人： Norihito KASADA

IPC分类号： G11B5/592 ,  G11B5/706 ,  G11B5/735

CPC分类号： G11B5/5928 ,  G11B5/70615 ,  G11B5/70678 ,  G11B5/7356

摘要： 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 μm to 50 μm, 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 μm 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.

公开(公告)号：US20240096364A1

公开(公告)日：2024-03-21

申请号：US18467474

申请日：2023-09-14

申请人： FUJIFILM Corporation

发明人： Norihito KASADA

IPC分类号： G11B5/706 ,  G11B5/008 ,  G11B5/588

CPC分类号： G11B5/70615 ,  G11B5/00817 ,  G11B5/588

摘要： The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which a friction coefficient measured on a base portion of a surface of the magnetic layer is 0.35 or less, and standard deviation σ of the friction coefficient in a width direction of the surface of the magnetic layer is 0.05 nm or less.

公开(公告)号：US11869553B2

公开(公告)日：2024-01-09

申请号：US17955156

申请日：2022-09-28

申请人： FUJIFILM Corporation

发明人： Norihito Kasada

IPC分类号： G11B5/592 ,  G11B5/735 ,  G11B5/706

CPC分类号： G11B5/5928 ,  G11B5/70615 ,  G11B5/70678 ,  G11B5/7356

摘要： 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 μm to 50 μm, 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 μm 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.

公开(公告)号：US11862212B2

公开(公告)日：2024-01-02

申请号：US17599843

申请日：2020-03-27

申请人： Sony Group Corporation

发明人： Junichi Tachibana ,  Noboru Sekiguchi

IPC分类号： G11B5/592 ,  G11B5/706 ,  G11B5/78

CPC分类号： G11B5/5928 ,  G11B5/706 ,  G11B5/78

摘要： [Solving Means] A magnetic recording medium according to an embodiment of the present technology is a tape-shaped magnetic recording medium, including: a magnetic layer including a servo band, a servo signal being recorded on the servo band. An index expressed by Sq×Fact.(p−p)/F0(p−p) is 0.42 or more, Sq being a squareness ratio of the magnetic layer in a perpendicular direction, F0(p−p) being a peak-to-peak value of a first magnetic force gradient strength observed by a magnetic force microscope when a servo signal is saturation-recorded on the magnetic layer, Fact.(p−p) being a peak-to-peak value of a second magnetic force gradient strength for the servo signal recorded on the servo band observed by the magnetic force microscope.

公开(公告)号：US20230290376A1

公开(公告)日：2023-09-14

申请号：US18182723

申请日：2023-03-13

申请人： FUJIFILM Corporation

发明人： Takashi FUJIMOTO ,  Eiki OZAWA

IPC分类号： G11B5/706 ,  G11B5/712 ,  G11B5/702

CPC分类号： G11B5/70642 ,  G11B5/712 ,  G11B5/702

摘要： The magnetic recording medium includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. A magnetic tape cartridge and a magnetic recording and reproducing device include the magnetic recording medium. The ferromagnetic powder is an ε-iron oxide powder, and a ferromagnetic powder filling rate of a magnetic layer surface obtained by observing a surface of the magnetic layer with a scanning electron microscope is 0.40 or more and 0.60 or less.

公开(公告)号：US11749306B2

公开(公告)日：2023-09-05

申请号：US17459659

申请日：2021-08-27

申请人： International Business Machines Corporation

发明人： Richard Bradshaw

IPC分类号： G11B5/848 ,  G11B5/716 ,  G11B5/714 ,  G11B5/702 ,  G11B5/706 ,  G11B5/712 ,  G11B5/71

CPC分类号： G11B5/848 ,  G11B5/7023 ,  G11B5/70621 ,  G11B5/70636 ,  G11B5/70647 ,  G11B5/712 ,  G11B5/714 ,  G11B5/716 ,  G11B5/71

摘要： A magnetic recording tape, in accordance with one aspect of the present invention, includes a substrate, an underlayer formed above the substrate, and a magnetic recording layer formed above the underlayer. The underlayer includes first encapsulated nanoparticles each comprising a first magnetic nanoparticle encapsulated by a first aromatic polymer, and a first polymeric binder binding the first encapsulated nanoparticles. The recording layer includes second encapsulated nanoparticles each comprising a second magnetic nanoparticle encapsulated by an encapsulating layer, and a second polymeric binder binding the second encapsulated nanoparticles.