MAGNETIC RECORDING MEDIUM

• US 20190027167A1
• Filed: 07/18/2018
• Published: 01/24/2019
• Est. Priority Date: 07/19/2017
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: TADA, Toshio, KASADA, Norihito, OZAWA, Eiki, KUROKAWA, Takuto
• Granted Patent: US 10,839,849 B2
• Time in Patent Office: Days
• CPC Class Codes: G11B 5/00813 magnetic tapes
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/70678 Ferrites
• CPC Class Codes: G11B 5/7085 non-magnetic abrasive particles
• CPC Class Codes: G11B 5/71 characterised by the lubricant
• CPC Class Codes: G11B 5/712 characterised by the surface treatment or coating of magnetic particles
• CPC Class Codes: G11B 5/714 characterised by the dimension of the magnetic particles
• CPC Class Codes: G11B 5/78 Tape carriers
• CPC Class Codes: G11B 5/84 Processes or apparatus specially adapted for manufacturing record carriers

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 %.

Claims

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.