公开(公告)号：US20250014603A1

公开(公告)日：2025-01-09

申请号：US18758784

申请日：2024-06-28

Applicant: FUJIFILM Corporation

Inventor： Ryosuke YUMIYAMA ,  Norihito KASADA ,  Nobuhito ONOZUKA ,  Junya SAWADA

IPC: G11B5/73 ,  G11B5/78

Abstract: The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. An arithmetic average curvature Spc of a peak point specified in ISO 25178 on a surface of the magnetic layer is 0.30 (1/μm) or more and 0.70 (1/μm) or less, and standard deviation a of the Spc in a width direction of the surface of the magnetic layer is 0.15 (1/μm) or less.

公开(公告)号：US20250078869A1

公开(公告)日：2025-03-06

申请号：US18820883

申请日：2024-08-30

Applicant: FUJIFILM Corporation

Inventor： Wataru KIKUCHI ,  Yutaka NOZOE ,  Nobuhito ONOZUKA

IPC: G11B5/725 ,  G11B5/008

Abstract: The magnetic recording medium includes a silicon-containing compound having a partial structure represented by Formula 1 (hereinafter, also simply referred to as a “silicon-containing compound”) in a portion on a non-magnetic support on a magnetic layer side. In Formula 1, R11, R12, and R13 each independently represent a monovalent substituent, L11 represents an (n+1)-valent linking group, n represents an integer of 2 or more, and * represents a position at which the partial structure represented by Formula 1 is bonded to another partial structure constituting the silicon-containing compound.

公开(公告)号：US20250014604A1

公开(公告)日：2025-01-09

申请号：US18758395

申请日：2024-06-28

Applicant: FUJIFILM Corporation

Inventor： Norihito KASADA ,  Nobuhito ONOZUKA ,  Junya SAWADA ,  Ryosuke YUMIYAMA

IPC: G11B5/78 ,  G11B5/55 ,  G11B5/592 ,  G11B5/706 ,  G11B5/714 ,  G11B5/735

Abstract: The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. Sci obtained by measuring a surface of the magnetic layer with an atomic force microscope and by Equation A is 1.40 or more and 1.60 or less, and standard deviation σ of the Sci in a width direction of the surface of the magnetic layer is 0.05 or less. In Equation A, Sq is a root-mean-square height Sq specified in ISO 25178, Vv(h0.05)-Vv(h0.8) is a void volume in a region where a load area ratio in a bearing curve is 5% or more and 80% or less, and A is a measurement region area. Sci = ( Vv ⁢ ( h 0.05 ) - Vv ⁢ ( h 0.8 ) A ) / Sq Equation ⁢ A

公开(公告)号：US20250006225A1

公开(公告)日：2025-01-02

申请号：US18759153

申请日：2024-06-28

Applicant: FUJIFILM Corporation

Inventor： Junya SAWADA ,  Norihito KASADA ,  Nobuhito ONOZUKA ,  Ryosuke YUMIYAMA

IPC: G11B5/706 ,  G11B5/592 ,  G11B5/714 ,  G11B5/735 ,  G11B5/78

Abstract: The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. A dale void volume Vvv specified in ISO 25178 on a surface of the magnetic layer is 0.100 nm3 or more and 0.350 nm3 or less, and standard deviation a of the Vvv in a width direction of the surface of the magnetic layer is 0.020 nm3 or less.

公开(公告)号：US20240355356A1

公开(公告)日：2024-10-24

申请号：US18644255

申请日：2024-04-24

Applicant: FUJIFILM CORPORATION

Inventor： Wataru KIKUCHI ,  Nobuhito ONOZUKA

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

CPC classification number: G11B5/7358 ,  G11B5/73923 ,  G11B5/78

Abstract: The magnetic recording medium includes a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which a nitrogen-containing polymer is included in a portion on the non-magnetic support on a magnetic layer side, the nitrogen-containing polymer contains a fluorine-containing group and a polyester chain, the fluorine-containing group is bonded to a nitrogen atom of the nitrogen-containing polymer, the polyester chain is bonded to the nitrogen atom of the nitrogen-containing polymer or forms a salt crosslinking structure with the nitrogen atom of the nitrogen-containing polymer, and a contact angle with water, which is measured on a surface of the magnetic layer after hexane cleaning, is 90° or more.