公开(公告)号：US20190259416A1

公开(公告)日：2019-08-22

申请号：US16397332

申请日：2019-04-29

Applicant: FUJIFILM Corporation

Inventor： Shinji KAWAKAMI ,  Sadamu KUSE ,  Kenji TANAKA ,  Shinji TSUJIMOTO

IPC: G11B5/714 ,  G11B5/70 ,  G11B5/706

Abstract: The magnetic recording medium includes a non-magnetic substrate, a non-magnetic layer, and a magnetic layer, wherein the magnetic layer contains a hexagonal strontium ferrite magnetic powder, Mr and t satisfy 0.0020 μT·m≤Mr·t≤0.0150 μT·m, where Mr is the residual magnetic flux density of the magnetic layer, and t is the average thickness of the magnetic layer, L1 satisfies 2 nm≤L1≤6 nm, where L1 is the average thickness of a first mixed layer that is formed on the surface of the magnetic layer opposite to the non-magnetic layer, L2 satisfies 0.1≤L2/t≤0.45, where L2 is the average thickness of a second mixed layer that is formed on the surface of the magnetic layer facing the non-magnetic layer.

公开(公告)号：US20200279679A1

公开(公告)日：2020-09-03

申请号：US16802797

申请日：2020-02-27

Applicant: FUJIFILM Corporation

Inventor： Shinji TSUJIMOTO

IPC: H01F1/34 ,  G11B5/65 ,  G11B5/735

Abstract: The magnetic tape includes a non-magnetic support, a magnetic layer that includes ferromagnetic powder having an average particle volume of 2,500 nm3 or less on one surface side of the non-magnetic support, and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which the ferromagnetic powder is ferromagnetic powder selected from the group consisting of hexagonal ferrite powder and ε-iron oxide powder, and a ratio (PSD5 μm-PSDmag/PSD10 μm-PSDbc) of the magnetic layer and the back coating layer is in a range of 0.0050 to 0.20. A magnetic tape cartridge and a magnetic recording and reproducing apparatus include the magnetic tape.

公开(公告)号：US20230178107A1

公开(公告)日：2023-06-08

申请号：US18161509

申请日：2023-01-30

Applicant: FUJIFILM Corporation

Inventor： Shinji TSUJIMOTO ,  Shunichi HOSHINO ,  Yoshihiro SAWAYASHIKI

IPC: G11B5/735 ,  G11B5/78

CPC classification number: G11B5/7353 ,  G11B5/78

Abstract: Provided are a magnetic tape including a non-magnetic support and a magnetic layer including a ferromagnetic powder, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape. An amount of a fluid lubricant collected by wiping a surface of the magnetic layer by a nonwoven fabric is in a range of 5 to 400 ng/m2 as a value per unit area of the surface of the magnetic layer.

公开(公告)号：US20170287518A1

公开(公告)日：2017-10-05

申请号：US15474504

申请日：2017-03-30

Applicant: FUJIFILM Corporation

Inventor： Toshihide AOSHIMA ,  Mika IMAMURA ,  Shinji TSUJIMOTO

IPC: G11B5/71 ,  C08K3/22 ,  G11B5/702 ,  C08K5/101

CPC classification number: G11B5/71 ,  C08K3/22 ,  C08K5/101 ,  C08K2003/2272 ,  G11B5/7021 ,  G11B5/7023 ,  G11B5/714

Abstract: The magnetic recording medium contains, in a magnetic layer, a fatty acid ester and a polyester resin having a number average molecular weight of greater than or equal to 1,000 but less than 20,000, and containing a structural unit derived from a polyvalent carboxylic acid and a structural unit derived from a polyol, as well as 10 mol % to 50 mol % of a structural unit, derived from a cyclic polyvalent carboxylic acid selected from the group consisting of an alicyclic polyvalent carboxylic acid and an aromatic polyvalent carboxylic acid, per 100 mol % of a combined total of the above structural units, and one or more partial structures selected from the group consisting of the following partial structures: wherein each of L1 and L2 independently denotes a divalent connecting group, and each of Z1 and Z2 independently denotes a monovalent group denoted by —OM or a monovalent group denoted by —O−A+.