Magnetic tape having characterized magnetic layer, magnetic tape cartridge, and magnetic tape apparatus

Patent metadata

Field	Value
Publication number	US-11508408-B2
Application number	US-202117160535-A
Country	US
Kind code	B2
Filing date	Jan 28, 2021
Priority date	Jan 31, 2020
Publication date	Nov 22, 2022
Grant date	Nov 22, 2022

Abstract

The magnetic tape in which a difference (S0.1−S1.6) between a spacing S0.1 and a spacing S1.6 obtained after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 32 nm. The S0.1 is a value obtained as a spacing under a pressing force of 0.1 atm from a relational expression between a pressure and a spacing obtained by performing a spacing measurement on the surface of the magnetic layer by an optical interference method under a pressing force of each of a plurality of different pressures after the n-hexane cleaning, and S1.6 is a spacing measured on the surface of the magnetic layer by the optical interference method under the pressing force of 1.6 atm after the n-hexane cleaning.

First claim

What is claimed is:

1. A magnetic tape comprising:
a non-magnetic support; and
a magnetic layer containing a ferromagnetic powder,
wherein a difference, S 0.1 −S 1.6 , between a spacing S 0.1 and a spacing S 1.6 each obtained after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 32 nm,
the spacing S 0.1 is a value obtained as a spacing under a pressing force of 0.1 atm from a relational expression between a pressure and a spacing obtained by performing a spacing measurement on the surface of the magnetic layer by an optical interference method under a pressing force of each of a plurality of different pressures after n-hexane cleaning, and
the spacing S 1.6 is a spacing measured on the surface of the magnetic layer by the optical interference method under a pressing force of 1.6 atm after n-hexane cleaning.

2. The magnetic tape according to claim 1 ,
wherein the difference is equal to or less than 30 nm.

3. The magnetic tape according to claim 1 ,
wherein the difference is equal to or more than 10 nm and equal to or less than 30 nm.

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

5. The magnetic tape according to claim 4 ,
wherein the inorganic oxide particles are composite particles of an inorganic oxide and a polymer.

6. The magnetic tape according to claim 1 ,
wherein a non-magnetic layer containing a non-magnetic powder is provided between the non-magnetic support and the magnetic layer.

7. The magnetic tape according to claim 1 ,
wherein a back coating layer containing a non-magnetic powder is provided 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 equal to or less than 5.3 μm.

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

10. The magnetic tape cartridge according to claim 9 ,
wherein the difference is equal to or less than 30 nm.

11. The magnetic tape cartridge according to claim 9 ,
wherein the difference is equal to or more than 10 nm and equal to or less than 30 nm.

12. The magnetic tape cartridge according to claim 9 ,
wherein the magnetic layer contains inorganic oxide particles.

13. The magnetic tape cartridge according to claim 12 ,
wherein the inorganic oxide particles are composite particles of an inorganic oxide and a polymer.

14. The magnetic tape cartridge according to claim 9 ,
wherein a non-magnetic layer containing a non-magnetic powder is provided between the non-magnetic support and the magnetic layer of the magnetic tape.

15. The magnetic tape cartridge according to claim 9 ,
wherein a back coating layer containing a non-magnetic powder is provided on a surface side of the non-magnetic support opposite to a surface side having the magnetic layer of the magnetic tape.

16. The magnetic tape cartridge according to claim 9 ,
wherein a tape thickness of the magnetic tape is equal to or less than 5.3 μm.

17. A magnetic tape apparatus comprising the magnetic tape cartridge according to claim 9 .

Assignees

• Fujifilm Corp

Inventors

• Kurokawa Takuto
• Sano Naoki
• Kasada Norihito

Classifications

• G11B5/714

  characterised by the dimension of the magnetic particles · CPC title

• G11B5/70678 Primary

  Ferrites · CPC title

• G11B5/7085 Primary

  non-magnetic abrasive particles · CPC title

• G11B5/00817

  on longitudinal tracks only, e.g. for serpentine format recording · CPC title

• G11B5/7356

  comprising non-magnetic particles in the back layer, e.g. particles of TiO2, ZnO or SiO2 · CPC title