MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING AND REPRODUCING DEVICE

• US 20190103134A1
• Filed: 09/26/2018
• Published: 04/04/2019
• Est. Priority Date: 09/29/2017
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: KASADA, Norihito, OZAWA, Eiki
• Granted Patent: US 10,854,231 B2
• Time in Patent Office: Days
• 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 5/735 characterised by the back layer magnetic recording media substrates G11B5/739
• CPC Class Codes: G11B 5/78 Tape carriers
• CPC Class Codes: G11B 5/84 Processes or apparatus specially adapted for manufacturing record carriers

Abstract

Provided are a magnetic recording medium, in which a magnetic layer includes ferromagnetic hexagonal ferrite powder, a binding agent, and an oxide abrasive, an intensity ratio Int(110)/Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00, a coefficient of friction measured regarding a base portion of a surface of the magnetic layer is equal to or smaller than 0.30, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm, and a magnetic recording and reproducing device including this magnetic recording medium.

Claims

1. A magnetic recording medium comprising:

a non-magnetic support; and

a magnetic layer including a ferromagnetic powder and a binding agent,

wherein the ferromagnetic powder is a ferromagnetic hexagonal ferrite powder,

the magnetic layer includes an oxide abrasive,

an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0,

a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00,

a coefficient of friction measured regarding a base portion of a surface of the magnetic layer is equal to or smaller than 0.30, and

an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μ

m to 0.08 μ

m.

2. The magnetic recording medium according to claim 1,

wherein the vertical squareness ratio is 0.65 to 0.90.

3. The magnetic recording medium according to claim 1,

wherein the coefficient of friction measured regarding the base portion of the surface of the magnetic layer is 0.15 to 0.30.

4. The magnetic recording medium according to claim 1,

wherein the oxide abrasive is an alumina powder.

5. The magnetic recording medium according to claim 1, further comprising:

a non-magnetic layer including a non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

6. The magnetic recording medium according to claim 1, further comprising:

a back coating layer including a non-magnetic powder and a binding agent on a surface of the non-magnetic support opposite to a surface provided with the magnetic layer.

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

8. A magnetic recording and reproducing device comprising:

a magnetic recording medium; and

a magnetic head,

wherein the magnetic recording medium is a magnetic recording medium comprising;

a non-magnetic support; and

a magnetic layer including a ferromagnetic powder and a binding agent,

wherein the ferromagnetic powder is a ferromagnetic hexagonal ferrite powder,

the magnetic layer includes an oxide abrasive,

an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0,

a vertical squareness ratio of the magnetic recording medium is 0.65 to 1.00,

a coefficient of friction measured regarding a base portion of a surface of the magnetic layer is equal to or smaller than 0.30, and

an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μ

m to 0.08 μ

m.

9. The magnetic recording and reproducing device according to claim 8,

wherein the magnetic head is a magnetic head including magnetoresistive element.

10. The magnetic recording and reproducing device according to claim 8,

wherein the vertical squareness ratio is 0.65 to 0.90.

11. The magnetic recording and reproducing device according to claim 8,

wherein the coefficient of friction measured regarding the base portion of the surface of the magnetic layer is 0.15 to 0.30.

12. The magnetic recording and reproducing device according to claim 8,

wherein the oxide abrasive is an alumina powder.

13. The magnetic recording and reproducing device according to claim 8,

wherein the magnetic recording medium comprises a non-magnetic layer including a non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

14. The magnetic recording and reproducing device according to claim 8,

wherein the magnetic recording medium comprises a back coating layer including a non-magnetic powder and a binding agent on a surface of the non-magnetic support opposite to a surface provided with the magnetic layer.

15. The magnetic recording and reproducing device according to claim 8,

wherein the magnetic recording medium is a magnetic tape.