Magnetic recording medium, magnetic tape cartridge, and magnetic recording and reproducing device

Patent metadata

Field	Value
Publication number	US-2025111864-A1
Application number	US-202418899572-A
Country	US
Kind code	A1
Filing date	Sep 27, 2024
Priority date	Sep 28, 2023
Publication date	Apr 3, 2025
Grant date	—

Abstract

The magnetic recording medium includes: a non-magnetic support; a magnetic layer containing a ferromagnetic powder; and a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer, in which a total chlorine content of the magnetic layer and the non-magnetic layer is 30.0 mg/m2 or less as a value per unit area, and a total iron content of the magnetic layer and the non-magnetic layer is 300.0 mg/m2 or less as a value per unit area.

First claim

What is claimed is:

1 . A magnetic recording medium comprising:
a non-magnetic support; a magnetic layer containing a ferromagnetic powder; and a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer, wherein a total chlorine content of the magnetic layer and the non-magnetic layer is 30.0 mg/m 2 or less as a value per unit area, and a total iron content of the magnetic layer and the non-magnetic layer is 300.0 mg/m 2 or less as a value per unit area.

2 . The magnetic recording medium according to claim 1 ,
wherein a void ratio of the non-magnetic layer is 10.0% or less in a cross section image captured by a scanning electron microscope.

3 . The magnetic recording medium according to claim 1 ,
wherein the non-magnetic powder of the non-magnetic layer includes carbon black.

4 . The magnetic recording medium according to claim 3 ,
wherein the non-magnetic layer contains 50.0% by mass or more of carbon black with respect to a total amount of the non-magnetic powder.

5 . The magnetic recording medium according to claim 1 ,
wherein a thickness of the non-magnetic layer is 1.00 m or less.

6 . The magnetic recording medium according to claim 1 , further comprising:
a back coating layer containing a non-magnetic powder on a surface side of the non-magnetic support opposite to a surface side having the non-magnetic layer and the magnetic layer.

7 . The magnetic recording medium according to claim 1 ,
wherein the magnetic recording medium is a magnetic tape.

8 . The magnetic recording medium according to claim 1 ,
wherein a void ratio of the non-magnetic layer is 10.0% or less in a cross section image captured by a scanning electron microscope, the non-magnetic layer contains 50.0% by mass or more of carbon black with respect to a total amount of the non-magnetic powder, a thickness of the non-magnetic layer is 1.00 m or less, the magnetic recording medium further comprises a back coating layer containing a non-magnetic powder on a surface side of the non-magnetic support opposite to a surface side having the non-magnetic layer and the magnetic layer, and the magnetic recording medium is a magnetic tape.

9 . A magnetic tape cartridge comprising:
the magnetic tape according to claim 7 .

10 . A magnetic recording and reproducing device comprising:
the magnetic recording medium according to claim 1 .

Assignees

• Fujifilm Corp

Inventors

• Mori Masahiko

Classifications

• G11B5/733

  characterised by the addition of non-magnetic particles {(base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739)} · CPC title

• G11B5/70678

  Ferrites · CPC title

• G11B5/7356

  comprising non-magnetic particles in the back layer, e.g. particles of TiO2, ZnO or SiO2 · CPC title

• G11B5/00813

  magnetic tapes · CPC title

• G11B5/66

  the record carriers consisting of several layers · CPC title