Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

Patent metadata

Field	Value
Publication number	US-11430476-B2
Application number	US-202117242798-A
Country	US
Kind code	B2
Filing date	Apr 28, 2021
Priority date	Jan 31, 2019
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

The magnetic tape includes a non-magnetic support and a magnetic layer including ferromagnetic powder and a binding agent, in which the magnetic layer has a timing-based servo pattern, an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference (L99.9−L0.1) between a value L99.9 of a cumulative distribution function of 99.9% and a value L0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and an isoelectric point of a surface zeta potential of the magnetic layer is 3.8 or less.

First claim

What is claimed is:

1. A magnetic tape comprising:
a non-magnetic support;
a magnetic layer including ferromagnetic powder and a binding agent;
a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer; and
a back coating layer including non-magnetic powder and a binding agent on a surface side of the non-magnetic support opposite to a surface side provided with the magnetic layer,
wherein the magnetic layer has a timing-based servo pattern,
wherein the ferromagnetic powder comprises hexagonal ferrite powder and/or ε-iron oxide powder,
wherein an edge shape of the timing-based servo pattern, specified by magnetic force microscopy is a shape in which a difference L 99.9 −L 0.1 between a value L 99.9 of a cumulative distribution function of 99.9% and a value L 0.1 of a cumulative distribution function of 0.1% in a position deviation width from an ideal shape of the magnetic tape in a longitudinal direction is 180 nm or less, and
wherein an isoelectric point of a surface zeta potential of the magnetic layer is 3.8 or less.

2. The magnetic tape according to claim 1 ,
wherein the isoelectric point is 2.5 or more and 3.8 or less.

3. The magnetic tape according to claim 1 ,
wherein the binding agent included in the magnetic layer is a binding agent containing an acidic group.

4. The magnetic tape according to claim 1 ,
wherein the timing-based servo pattern is a linear servo pattern which continuously extends from one side of the magnetic tape in a width direction to the other side thereof and is inclined at an angle α with respect to the width direction, and
wherein the ideal shape is a linear shape extending in a direction of the angle α.

5. The magnetic tape according to claim 1 ,
wherein the difference L 99.9 −L 0.1 is 100 nm or more and 180 nm or less.

6. The magnetic tape according to claim 1 ,
wherein the thickness of the non-magnetic support ranges from 3.00 μm to 5.00 μm.

7. The magnetic tape according to claim 1 ,
wherein the thickness of the non-magnetic layer ranges from 0.10 μm to 1.00 μm.

8. The magnetic tape according to claim 1 ,
wherein the ferromagnetic powder is vertically oriented.

9. A magnetic tape cartridge comprising:
the magnetic tape according to claim 1 .

10. The magnetic tape cartridge according to claim 9 ,
wherein the isoelectric point is 2.5 or more and 3.8 or less.

11. The magnetic tape cartridge according to claim 9 ,
wherein the binding agent included in the magnetic layer is a binding agent containing an acidic group.

12. The magnetic tape cartridge according to claim 9 ,
wherein the ferromagnetic powder is vertically oriented.

13. The magnetic tape cartridge according to claim 9 ,
wherein the timing-based servo pattern is a linear servo pattern which continuously extends from one side of the magnetic tape in a width direction to the other side thereof and is inclined at an angle α with respect to the width direction, and
wherein the ideal shape is a linear shape extending in a direction of the angle α.

14. The magnetic tape cartridge according to claim 9 ,
wherein the difference L 99.9 −L 0.1 is 100 nm or more and 180 nm or less.

15. A magnetic tape apparatus comprising:
a magnetic tape;
a reading element unit; and
an extraction unit,
wherein the magnetic tape is the magnetic tape according to claim 1 ,
wherein the reading element unit includes a plurality of reading elements each of which reads data from a specific track region including a reading target track in a track region included in the magnetic tape, and
wherein the extraction unit performs a waveform equalization process with respect to each reading result for each reading element, to extract, from the reading result, data derived from the reading target track.

16. The magnetic tape apparatus according to claim 15 ,
wherein the isoelectric point is 2.5 or more and 3.8 or less.

17. The magnetic tape apparatus according to claim 15 ,
wherein the binding agent included in the magnetic layer is a binding agent containing an acidic group.

18. The magnetic tape apparatus according to claim 15 ,
wherein the ferromagnetic powder is vertically oriented.

19. The magnetic tape apparatus according to claim 15 ,
wherein the timing-based servo pattern is a linear servo pattern which continuously extends from one side of the magnetic tape in a width direction to the other side thereof and is inclined at an angle α with respect to the width direction, and
wherein the ideal shape is a linear shape extending in a direction of the angle α.

20. The magnetic tape apparatus according to claim 15 ,
wherein the difference L 99.9 −L 0.1 is 100 nm or more and 180 nm or less.

Assignees

• Fujifilm Corp

Inventors

• Kasada Norihito
• Ozawa Eiki
• Musha Atsushi

Classifications

• G11B5/708

  characterised by addition of non-magnetic particles to the layer · CPC title

• G11B5/3958

  the active elements being arranged in a single plane, e.g. "matrix" disposition · CPC title

• G11B5/7022

  containing mixtures of polyurethanes or polyisocyanates with other polymers · CPC title

• B82Y10/00

  Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic · CPC title

• G11B2005/0013

  of transducers, e.g. linearisation, equalisation · CPC title