Granted Patent B2

US 12,322,425 · App. 18/516,132 · Granted Jun 3, 2025

Inventor: Norihito Kasada (Minamiashigara, JP)

Assignee: FUJIFILM Corporation

G11B5/7356G11B5/7085G11B5/78

Abstract

Claims (40)

1. A magnetic tape comprising:

a non-magnetic support; and

a magnetic layer containing a ferromagnetic powder,

wherein

the non-magnetic support is polyethylene terephthalate, polyethylene naphthalate or polyamide,

a tape thickness of the magnetic tape is 5.2 μm or less, and

in an environment with a temperature of 23° C. and a relative humidity of 50%,

an AlFeSil abrasion value 45° of a surface of the magnetic layer measured at a tilt angle of 45° of an AlFeSil prism is 20 μm to 50 μm,

a standard deviation of an AlFeSil abrasion value of the surface of the magnetic layer measured at each of tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil prism is 30 μm or less, and

the tilt angle of the AlFeSil prism is an angle formed by a longitudinal direction of the AlFeSil prism and a width direction of the magnetic tape.

2. The magnetic tape according to claim 1 ,

wherein the standard deviation of the AlFeSil abrasion value is 15 μm to 30 μm.

3. The magnetic tape according to claim 1 ,

wherein the tape thickness is 4.0 μm to 5.2 μm.

4. The magnetic tape according to claim 1 ,

wherein the tape thickness is 4.0 μm to 5.0 μm.

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 one or more kinds of non-magnetic powder.

7. The magnetic tape according to claim 6 ,

wherein the non-magnetic powder includes an alumina powder.

8. 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.

9. The magnetic tape according to claim 8 ,

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

10. 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.

11. The magnetic tape device according to claim 1 ,

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

12. The magnetic tape device according to claim 1 ,

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

13. A magnetic tape cartridge comprising:

the magnetic tape according to claim 1 .

14. A magnetic tape device comprising:

the magnetic tape according to claim 1 .

15. The magnetic tape device according to claim 14 , 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 the width direction of the magnetic tape during running of the magnetic tape in the magnetic tape device.

Priority Claims (2)

Continuity (2)

References Cited (268)