IP Library Granted Patent US 11,900,977
Granted Patent B2
US 11,900,977 · App. 17/955,113 · Granted Feb 13, 2024

Magnetic tape having characterized magnetic layer surface, magnetic tape cartridge, and magnetic tape device

Inventor: Norihito Kasada (Minamiashigara, JP)
Assignee: FUJIFILM Corporation
G11B5/70615G11B5/7334G11B5/78
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Quick Facts
Patent No.
US 11,900,977
App. No.
17/955,113
Granted
Feb 13, 2024
Kind
B2
Abstract

A magnetic tape in which an arithmetic average roughness Ra measured at a surface of a magnetic layer with an atomic force microscope is 2.0 nm or less, and in an environment with a temperature of 32° C. and a relative humidity of 80%, a frictional force F 45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.

Claims (43)

1. A magnetic tape comprising:

a non-magnetic support; and

a magnetic layer containing a ferromagnetic powder,

wherein an arithmetic average roughness Ra measured at a surface of the magnetic layer with an atomic force microscope is 2.0 nm or less, and

in an environment with a temperature of 32° C. and a relative humidity of 80%,

a frictional force F 45° on the surface of the magnetic layer with respect to an LTO8 head measured at a head tilt angle of 45° is 4 gf to 15 gf, and

a standard deviation of a frictional force F on the surface of the magnetic layer with respect to the LTO8 head measured at each of head tilt angles of 0°, 15°, 30°, and 45° is 10 gf or less.

2. The magnetic tape according to claim 1 ,

wherein the standard deviation of F is 2 gf to 10 gf.

3. The magnetic tape according to claim 1 ,

wherein the arithmetic average roughness Ra is 1.0 nm to 2.0 nm.

4. The magnetic tape according to claim 1 ,

wherein the arithmetic average roughness Ra is 1.0 nm to 1.6 nm.

5. The magnetic tape according to claim 1 ,

wherein a standard deviation of curvature of the magnetic tape in a longitudinal direction is 5 mm/m or less.

6. The magnetic tape according to claim 1 ,

wherein the magnetic layer contains inorganic oxide-based particles.

7. The magnetic tape according to claim 6 ,

wherein the inorganic oxide-based particles are composite particles of an inorganic oxide and a polymer.

8. The magnetic tape according to claim 1 ,

wherein the magnetic layer contains carbon black.

9. The magnetic tape according to claim 1 , further comprising:

a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer.

10. The magnetic tape according to claim 1 ,

wherein a thickness of the non-magnetic layer is 0.1 m to 0.7 m.

11. The magnetic tape 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 provided with the magnetic layer.

12. The magnetic tape according to claim 1 ,

wherein a tape thickness is 5.2 μm or less.

13. The magnetic tape according to claim 1 ,

wherein a tape thickness is 5.0 μm or less.

14. The magnetic tape according to claim 1 ,

wherein a vertical squareness ratio of the magnetic tape is 0.60 or more.

15. The magnetic tape according to claim 1 ,

wherein a vertical squareness ratio of the magnetic tape is 0.65 or more.

16. A magnetic tape cartridge comprising:

the magnetic tape according to claim 1 .

17. A magnetic tape device comprising:

the magnetic tape according to claim 1 .

18. The magnetic tape device according to claim 17 , further comprising:

a magnetic head,

wherein the magnetic head includes a module including an element array having a plurality of magnetic head elements between a pair of servo signal reading elements, and

the magnetic tape device changes an angle θ formed by an axis of the element array with respect to a width direction of the magnetic tape during running of the magnetic tape in the magnetic tape device.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 30, 2022
From: KASADA, NORIHITO
To: FUJIFILM CORPORATION
Reel/Frame 061264/0528 →
Priority Claims (2)
JP 2021-158781 · Sep 29, 2021 · national
JP 2022-138376 · Aug 31, 2022 · national
Continuity (1)
Related Publication 20230115333A1 · Apr 13, 2023