公开(公告)号：US12260977B2

公开(公告)日：2025-03-25

申请号：US17173437

申请日：2021-02-11

Applicant: FUJIFILM Corporation

Inventor： Hirokazu Hashimoto

IPC: H01F1/34 ,  C01G49/00 ,  H01Q17/00

Abstract: The powder of the magnetoplumbite-type hexagonal ferrite is an aggregate of particles of a compound represented by Formula (1), and, in a particle size distribution based on number measured by a laser diffraction scattering method, in a case where a mode value is defined as a mode diameter, a diameter at a cumulative percentage of 10% is defined as D10 and a diameter at a cumulative percentage of 90% is defined as D90, the mode diameter is equal to or greater than 5 μm and less than 10 μm and an expression of (D90−D10)/mode diameter≤3.0 is satisfied. In Formula (1), A represents at least one metal element selected from the group consisting of Sr, Ba, Ca, and Pb, and x satisfies 1.5≤x≤8.0. AFe(12-x)AlxO19  Formula(1)

公开(公告)号：US12142834B2

公开(公告)日：2024-11-12

申请号：US17518889

申请日：2021-11-04

Applicant: FUJIFILM Corporation

Inventor： Hirokazu Hashimoto

IPC: H01Q17/00 ,  C01G49/00 ,  H01F1/34

Abstract: There is provided a radio wave absorber including a magnetic powder and a binder, in which a volume filling rate of the magnetic powder in the radio wave absorber is 35% by volume or less, and a volume filling rate of a carbon component in the radio wave absorber is 0% by volume or more and 2.0% by volume or less.

公开(公告)号：US12125622B2

公开(公告)日：2024-10-22

申请号：US17469166

申请日：2021-09-08

Applicant: FUJIFILM Corporation

Inventor： Hirokazu Hashimoto

IPC: H01F1/34 ,  C01G49/06 ,  H01F1/36 ,  H01F1/37 ,  H05K9/00

CPC classification number: H01F1/348 ,  C01G49/06 ,  H05K9/0075 ,  C01P2002/76 ,  C01P2006/42

Abstract: A magnetoplumbite-type hexagonal ferrite powder containing a powder of a magnetoplumbite-type hexagonal ferrite represented by Formula (1) and a powder of a compound represented by Formula (2), in which a magnetic field strength Hα, which corresponds to 90% of a magnetization quantity obtained in a case where an external magnetic field of 50 kOe is applied, satisfies 19 kOe≤Hα≤28 kOe, a radio wave absorber, and a method of controlling resonance frequency of a magnetoplumbite-type hexagonal ferrite powder are provided. In Formula (1), A represents at least one metal element selected from the group consisting of Sr, Ba, Ca, and Pb, and x satisfies 1.5≤x≤8.0. In Formula (2), Aa represents at least one metal element selected from the group consisting of Sr, Ba, Ca, and Pb.

AFe(12-x)AlxO19  Formula (1)

AaAl2O4  Formula (2)

公开(公告)号：US10783023B2

公开(公告)日：2020-09-22

申请号：US16120329

申请日：2018-09-03

Applicant: FUJIFILM CORPORATION

Inventor： Naoaki Tokai ,  Hirokazu Hashimoto ,  Yosuke Sumiya

IPC: G06F11/00 ,  G06F11/07 ,  G11B5/008 ,  G06F3/06 ,  G11B23/107 ,  G11B23/02 ,  G11B23/04 ,  G06K19/07

Abstract: A recording control device, a recording control method, and a recording tape cartridge capable of estimating a lifetime of the recording tape cartridge are obtained. A recording control device reads information correlated with an error rate of reading or writing of data from or to a magnetic tape included in a recording tape cartridge, the information being recorded on a RFID tag included in the recording tape cartridge, and a measurement date of the information, and estimates a lifetime of the recording tape cartridge using the read information and the read measurement date, and the information measured at the time of using the recording tape cartridge and a measurement date.

公开(公告)号：US20220166147A1

公开(公告)日：2022-05-26

申请号：US17666984

申请日：2022-02-08

Applicant: FUJIFILM Corporation

Inventor： Yoshihiro NAKAI ,  Hirokazu Hashimoto

IPC: H01Q17/00 ,  H05K9/00 ,  C01G49/00 ,  C08K9/06

Abstract: There is provided a radio wave absorbing composition containing a magnetic powder and a binder. There is also provided a radio wave absorber containing a magnetic powder and a binder. The magnetic powder is a powder of a substitution-type hexagonal ferrite subjected to surface treatment with a surface treatment agent, the surface treatment agent is a silicon-based compound, and the binder is an olefin-based resin.

公开(公告)号：US12112871B2

公开(公告)日：2024-10-08

申请号：US17176296

申请日：2021-02-16

Applicant: FUJIFILM Corporation

Inventor： Hirokazu Hashimoto

IPC: H01F1/34 ,  C01G49/00 ,  C30B29/22 ,  H01F1/36 ,  H05K9/00

CPC classification number: H01F1/348 ,  C01G49/0045 ,  C30B29/22 ,  H05K9/0081 ,  C01P2002/50 ,  C01P2002/76 ,  C01P2006/42

Abstract: A powder mixture of a magnetoplumbite-type hexagonal ferrite is a mixture of powders of two or more kinds of compounds represented by Formula (1), the two or more kinds of compounds represented by Formula (1) are two or more kinds of compounds having different values of x in Formula (1), and are a powder mixture satisfying a relationship of xmax−xmin≤0.2, in a case where a maximum value of x is defined as xmax and a minimum value of x is defined as xmin, in two or more kinds of compounds having different values of x in Formula (1), and the application. In Formula (1), A represents at least one metal element selected from the group consisting of Sr, Ba, Ca, and Pb, and x satisfies 1.5≤x≤8.0.

AFe(12-x)AlxO19  Formula (1)

公开(公告)号：US12183495B2

公开(公告)日：2024-12-31

申请号：US17176279

申请日：2021-02-16

Applicant: FUJIFILM Corporation

Inventor： Hirokazu Hashimoto

IPC: H01F1/34 ,  H01F1/36 ,  H01F1/37 ,  H05K9/00

Abstract: A method for producing a powder of a magnetoplumbite-type hexagonal ferrite which is an aggregate of particles of a compound represented by Formula (1), the method including: a step A of adjusting a pH of an aqueous solution containing a Fe salt, an Al salt, and at least one metal element salt selected from the group consisting of a Sr salt, a Ba salt, a Ca salt, and a Pb salt to exceed 8.0, thereby obtaining a reaction product; a step B of drying the reaction product obtained in the step A, thereby obtaining a dried product; and a step C of firing the dried product obtained in Step B, thereby obtaining a fired product, and application. In Formula (1), A represents at least one metal element selected from the group consisting of Sr, Ba, Ca, and Pb, and x satisfies 1.5≤x≤8.0. AFe(12-x)AlxO19  Formula (1)

公开(公告)号：US12160984B2

公开(公告)日：2024-12-03

申请号：US17518825

申请日：2021-11-04

Applicant: FUJIFILM Corporation

Inventor： Masashi Shirata ,  Hirokazu Hashimoto

IPC: H05K9/00 ,  H01F1/11 ,  H01F1/113 ,  H01F1/34 ,  H01F1/37

Abstract: There is provided a radio wave absorber including a powder of a hexagonal ferrite; and a binder, in which the radio wave absorber has a squareness ratio in a range of 0.40 to 0.60.