IP Library › Granted Patent US 12,614,563
Granted Patent B2
US 12,614,563 · App. 18/467,474 · Granted Apr 28, 2026

Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

Inventor: Norihito Kasada (Minamiashigara, JP)
Assignee: FUJIFILM Corporation
G11B5/70615G11B5/00817G11B5/588
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Quick Facts
Patent No.
US 12,614,563
App. No.
18/467,474
Granted
Apr 28, 2026
Kind
B2
Abstract

The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which a friction coefficient measured on a base portion of a surface of the magnetic layer is 0.35 or less, and standard deviation σ of the friction coefficient in a width direction of the surface of the magnetic layer is 0.05 nm or less.

Claims (43)

1 . A magnetic tape comprising:

a non-magnetic support; and

a magnetic layer containing a ferromagnetic powder,

wherein a friction coefficient measured on a base portion of a surface of the magnetic layer is 0.35 or less,

standard deviation σ of the friction coefficient in a width direction of the surface of the magnetic layer is 0.05 nm or less, and

a non-linear component of tape width deformation generated by storage for 10 days in an environment of a temperature of 60° C. and a relative humidity of 20% is 70 nm or less,

said non-linear component of tape width deformation being determined from an absolute value of a difference between (i) a non-linear component of tape width deformation at an initial stage where the magnetic tape is wound around a reel and stored for 24 hours or longer at 20° C. to 25° C. and a relative humidity of 40% to 60% and (ii) a non-linear component of tape width deformation after storage for 10 days at 60° C. and a relative humidity of 20%.

2 . The magnetic tape according to claim 1 ,

wherein the friction coefficient measured on the base portion is 0.20 or more and 0.35 or less.

3 . The magnetic tape according to claim 1 ,

wherein the standard deviation σ of the friction coefficient is 0.01 or more and 0.05 or less.

4 . The magnetic tape according to claim 1 ,

wherein the standard deviation σ of the friction coefficient is 0.01 or more and 0.02 or less.

5 . 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.

6 . The magnetic tape according to claim 5 ,

wherein a thickness of the non-magnetic layer is 0.1 μm or more and 0.7 μm or less.

7 . 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 having the magnetic layer.

8 . The magnetic tape according to claim 1 ,

wherein a tape thickness is 5.2 μm or less.

9 . The magnetic tape according to claim 1 ,

wherein a tape thickness is 5.0 μm or less.

10 . The magnetic tape according to claim 1 ,

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

11 . The magnetic tape according to claim 1 ,

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

12 . The magnetic tape according to claim 1 ,

wherein the friction coefficient measured on the base portion is 0.20 or more and 0.35 or less,

the standard deviation σ of the friction coefficient is 0.01 or more and 0.02 or less,

the magnetic tape further includes a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer,

a thickness of the non-magnetic layer is 0.1 μm or more and 0.7 μm or less,

the magnetic tape further includes a back coating layer containing a non-magnetic powder on a surface side of the non-magnetic support opposite to a surface side having the magnetic layer,

a tape thickness is 5.0 μm or less, and

a perpendicular 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 apparatus comprising:

the magnetic tape according to claim 1 .

15 . The magnetic tape apparatus according to claim 14 , further comprising:

a magnetic head,

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

the magnetic tape apparatus 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 apparatus.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 18, 2023
From: KASADA, NORIHITO
To: FUJIFILM CORPORATION
Reel/Frame 064938/0971 →
Priority Claims (1)
JP 2022-146870 · Sep 15, 2022 · national
Continuity (1)
Related Publication 20240096364A1 · Mar 21, 2024
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