Magnetic recording medium having characterized magnetic layer

Patent metadata

Field	Value
Publication number	US-10839849-B2
Application number	US-201816038669-A
Country	US
Kind code	B2
Filing date	Jul 18, 2018
Priority date	Jul 19, 2017
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

The magnetic recording medium includes a non-magnetic support and a magnetic layer, wherein the magnetic layer contains ferromagnetic hexagonal ferrite powder and an abrasive, Int (110)/Int (114) of a crystal structure of the hexagonal ferrite determined by performing XRD analysis on the magnetic layer by using an In-Plane method is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, one or more kinds of components selected from the group consisting of a fatty acid and a fatty acid amide is contained in a magnetic layer side portion on the support, and a C—H-derived C concentration obtained by ESCA within a surface of the magnetic layer at a photoelectron take-off angle of 10° is equal to or higher than 45 at %.

First claim

What is claimed is:

1. A magnetic recording medium comprising:
a non-magnetic support; and
a magnetic layer which is provided on the support,
wherein the magnetic layer contains ferromagnetic powder, a binder and an abrasive,
the ferromagnetic powder is ferromagnetic hexagonal ferrite powder,
an intensity ratio (Int (110)/Int (114)) of a peak intensity Int (110) of a diffraction peak of (110) plane of a crystal structure of the hexagonal ferrite, determined by performing X-ray diffraction analysis on the magnetic layer by using an In-Plane method, to a peak intensity Int (114) of a diffraction peak of (114) plane of the crystal structure is equal to or higher than 0.5 and equal to or lower than 4.0,
a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00,
one or more kinds of components selected from the group consisting of a fatty acid and a fatty acid amide is contained in a magnetic layer side portion on the support, and
a C—H-derived C concentration calculated from a C—H peak surface area ratio in a C1s spectrum, which is obtained by X-ray photoelectron spectroscopy performed within a surface of the magnetic layer at a photoelectron take-off angle of 10°, is equal to or higher than 45 at %.

2. The magnetic recording medium according to claim 1 ,
wherein the squareness ratio in a vertical direction is equal to or higher than 0.65 and equal to or lower than 0.90.

3. The magnetic recording medium according to claim 1 ,
wherein the C—H-derived C concentration of the magnetic layer is equal to or higher than 45 at % and equal to or lower than 80 at %.

4. The magnetic recording medium according to claim 2 ,
wherein the C—H-derived C concentration of the magnetic layer is equal to or higher than 45 at % and equal to or lower than 80 at %.

5. The magnetic recording medium according to claim 1 , further comprising:
a non-magnetic layer containing non-magnetic powder and a binder between the non-magnetic support and the magnetic layer.

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

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

Assignees

• Fujifilm Corp

Inventors

• Tada Toshio
• Kasada Norihito
• Ozawa Eiki
• Kurokawa Takuto

Classifications

• G11B5/714

  characterised by the dimension of the magnetic particles · CPC title

• G11B5/712

  characterised by the surface treatment or coating of magnetic particles · CPC title

• G11B5/7085

  non-magnetic abrasive particles · CPC title

• G11B5/71 Primary

  characterised by the lubricant · CPC title

• G11B5/70678

  Ferrites · CPC title