Magnetic tape and magnetic tape device

• US 9,779,772 B1
• Filed: 03/21/2017
• Issued: 10/03/2017
• Est. Priority Date: 03/22/2016
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Kasada, Norihito, Kaneko, Tetsuya, Ozawa, Eiki
• Primary Examiner(s): Cao, Allen T
• Application Number:
  US15/464,991
• Publication Number:
  US 20170278533A1
• Time in Patent Office: 196 Days
• Field of Search: 360134
• CPC Class Codes: G11B 5/5926 recorded in separate tracks, e.g. servo tracks
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/712 characterised by the surface treatment or coating of magnetic particles
• CPC Class Codes: G11B 5/78 Tape carriers

Abstract

The magnetic tape has a magnetic layer containing ferromagnetic powder and binder on a nonmagnetic support, wherein a timing based servo pattern is present on the magnetic layer, the centerline average surface roughness Ra that is measured on the surface of the magnetic layer is less than or equal to 1.8 nm, and the coefficient of friction that is measured on the base portion of the surface of the magnetic layer is less than or equal to 0.35.

Claims

1. A magnetic tape,

which comprises a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, wherein

a timing based servo pattern is present on the magnetic layer;

a centerline average surface roughness Ra that is measured on a surface of the magnetic layer is less than or equal to 1.8 nm; and

a coefficient of friction that is measured on a base portion of the surface of the magnetic layer is less than or equal to 0.35.

2. The magnetic tape according to claim 1,

wherein the coefficient of friction that is measured on the base portion falls within a range of 0.15 to 0.35.

3. The magnetic tape according to claim 1,

wherein the coefficient of friction that is measured on the base portion falls within a range of 0.15 to 0.30.

4. The magnetic tape according to claim 1,

wherein the centerline average surface roughness Ra falls within a range of 1.2 nm to 1.8 nm.

5. The magnetic tape according to claim 1,

wherein the centerline average surface roughness Ra falls within a range of 1.2 nm to 1.6 nm.

6. The magnetic tape according to claim 1,

which comprises a nonmagnetic layer comprising nonmagnetic powder and binder between the nonmagnetic support and the magnetic layer.

7. The magnetic tape according to claim 1,

wherein the coefficient of friction that is measured on the base portion fails within a range of 0.20 to 0.35;

and

the centerline average surface roughness Ra falls within a range of 1.5 nm to 1.8 nm.

8. A magnetic tape device,

which comprises a magnetic tape, a magnetic head and a servo head, wherein

the magnetic tape is a magnetic tape which comprises a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, wherein

a timing based servo pattern is present on the magnetic layer;

a centerline average surface roughness Ra that is measured on a surface of the magnetic layer is less than or equal to 1.8 nm; and

a coefficient of friction that is measured on a base portion of the surface of the magnetic layer is less than or equal to 0.35.

9. The magnetic tape device according to claim 8,

wherein the coefficient of friction that is measured on the base portion falls within a range of 0.15 to 0.35.

10. The magnetic tape device according to claim 8,

wherein the coefficient of friction that is measured on the base portion falls within a range of 0.15 to 0.30.

11. The magnetic tape device according to claim 8,

wherein the centerline average surface roughness Ra falls within a range of 1.2 nm to 1.8 nm.

12. The magnetic tape device according to claim 8,

wherein the centerline average surface roughness Ra falls within a range of 1.2 nm to 1.6 nm.

13. The magnetic tape device according to claim 8,

wherein the magnetic tape comprises a nonmagnetic layer comprising nonmagnetic powder and binder between the nonmagnetic support and the magnetic layer.

14. The magnetic tape device according to claim 8,

wherein the coefficient of friction that is measured on the base portion falls within a range of 0.20 to 0.35;

and

the centerline average surface roughness Ra falls within a range of 1.5 nm to 1.8 nm.