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

Patent metadata

Field	Value
Publication number	US-12308059-B2
Application number	US-202318524342-A
Country	US
Kind code	B2
Filing date	Nov 30, 2023
Priority date	Sep 29, 2021
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

A magnetic tape in which a vertical switching field distribution SFD of the magnetic tape is 1.5 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.

First claim

What is claimed is:

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 vertical switching field distribution SFD of the magnetic tape is 1.5 or less, and
in an environment with a temperature of 32° C. and a relative humidity of 80%,
a frictional force F 45 ° on a 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 vertical switching field distribution SFD of the magnetic tape is 0.5 to 1.5.

4. 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.

5. The magnetic tape according to claim 1 ,
wherein the magnetic layer contains inorganic oxide-based particles.

6. The magnetic tape according to claim 5 ,
wherein the inorganic oxide-based particles are composite particles of an inorganic oxide and a polymer.

7. The magnetic tape according to claim 1 ,
wherein the magnetic layer contains carbon black.

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 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.

10. The magnetic tape according to claim 1 ,
wherein a tape thickness is 5.2 μm or less.

11. The magnetic tape according to claim 1 ,
wherein the standard deviation of F is 2 gf to 10 gf,
the vertical switching field distribution SFD of the magnetic tape is 0.5 to 1.5,
a standard deviation of curvature of the magnetic tape in a longitudinal direction is 5 mm/m or less,
the magnetic layer contains composite particles of an inorganic oxide and a polymer,
the magnetic tape further comprises:
a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer, and
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, and
a tape thickness is 5.2 μm or less.

12. The magnetic tape according to claim 1 ,
wherein the standard deviation of F is 2 gf to 10 gf,
the vertical switching field distribution SFD of the magnetic tape is 0.5 to 1.5,
a standard deviation of curvature of the magnetic tape in a longitudinal direction is 5 mm/m or less,
the magnetic layer contains carbon black,
the magnetic tape further comprises:
a non-magnetic layer containing a non-magnetic powder between the non-magnetic support and the magnetic layer, and
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, and
a tape thickness is 5.2 μm or less.

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 having an element array including 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.

Assignees

• Fujifilm Corp

Inventors

• Kasada Norihito

Classifications

• G11B5/78

  Tape carriers · CPC title

• G11B5/68

  comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent · CPC title

• G11B5/7334 Primary

  Base layer characterised by composition or structure · CPC title