IP Library Granted Patent US 11,367,461
Granted Patent B2
US 11,367,461 · App. 16/857,502 · Granted Jun 21, 2022

Magnetic recording medium having characterized magnetic layer, and magnetic recording and reproducing apparatus

Inventor: Norihito Kasada (Minami-ashigara, JP)
Assignee: FUJIFILM Corporation
G11B5/733G01B9/02G01B11/30G11B5/7028G11B5/70605G11B5/70678G11B5/73937G11B5/7356G11B5/78
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Quick Facts
Patent No.
US 11,367,461
App. No.
16/857,502
Granted
Jun 21, 2022
Kind
B2
Abstract

The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a difference S after −S before between a spacing S after measured on a surface of the magnetic layer by optical interferometry after methyl-ethyl-ketone cleaning and a spacing S before measured on the surface of the magnetic layer by optical interferometry before methyl-ethyl-ketone cleaning is more than 0 nm and 15.0 nm or less, and the non-magnetic support is an aromatic polyamide support having a moisture absorption of 2.2% or less.

Claims (31)

1. A magnetic recording medium comprising:

a non-magnetic support; and

a magnetic layer including ferromagnetic powder,

wherein a difference S after −S before between a spacing S after measured on a surface of the magnetic layer by optical interferometry after methyl-ethyl-ketone cleaning and a spacing S before measured on the surface of the magnetic layer by optical interferometry before methyl-ethyl-ketone cleaning is more than 0 nm and 15.0 nm or less, and

the non-magnetic support is an aromatic polyamide support having a moisture absorption of 2.2% or less.

2. The magnetic recording medium according to claim 1 ,

wherein the difference S after −S before is 3.0 nm or more and 15.0 nm or less.

3. The magnetic recording medium according to claim 1 ,

wherein the moisture absorption of the aromatic polyamide support is 2.0% or less.

4. The magnetic recording medium according to claim 1 ,

wherein the moisture absorption of the aromatic polyamide support is 1.0% or more and 2.0% or less.

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

a non-magnetic layer including non-magnetic powder 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 non-magnetic powder on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer.

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

8. A magnetic recording and reproducing apparatus comprising:

the magnetic recording medium according to claim 1 ; and

a magnetic head.

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

wherein the difference S after −S before is 3.0 nm or more and 15.0 nm or less.

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

wherein the moisture absorption of the aromatic polyamide support is 2.0% or less.

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

wherein the moisture absorption of the aromatic polyamide support is 1.0% or more and 2.0% or less.

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

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

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

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

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

wherein the magnetic recording medium is a magnetic tape.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 24, 2020
From: KASADA, NORIHITO
To: FUJIFILM CORPORATION
Reel/Frame 052487/0791 →
Priority Claims (1)
JP JP2019-086681 · Apr 26, 2019 · national
Continuity (1)
Related Publication 20200342903A1 · Oct 29, 2020