Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

Patent metadata

Field	Value
Publication number	US-2020211592-A1
Application number	US-201916727181-A
Country	US
Kind code	A1
Filing date	Dec 26, 2019
Priority date	Dec 28, 2018
Publication date	Jul 2, 2020
Grant date	—

Abstract

Provided are a magnetic tape including: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape, a magnetic tape cartridge and a magnetic tape apparatus including this magnetic tape.

First claim

What is claimed is:

1 . A magnetic tape comprising:
a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, wherein a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40.

2 . The magnetic tape according to claim 1 ,
wherein a difference Nxy−Nz between the refractive index Nxy and the refractive index Nz is 0.25 to 0.40.

3 . The magnetic tape according to claim 1 , further comprising:
a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

4 . The magnetic tape according to claim 1 ,
wherein the total thickness of the magnetic tape is 3.00 μm to 5.30 μm.

5 . The magnetic tape according to claim 1 , further comprising:
a back coating layer including non-magnetic powder and a binding agent on a surface of the non-magnetic support opposite to a surface provided with the magnetic layer.

6 . The magnetic tape according to claim 1 ,
wherein the center line average surface roughness Ra measured on the surface of the magnetic layer is 1.2 nm to 1.8 nm.

7 . The magnetic tape according to claim 1 ,
wherein the servo pattern is a timing-based servo pattern.

8 . A magnetic tape cartridge comprising:
a magnetic tape, which comprises: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, wherein a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40.

9 . The magnetic tape cartridge according to claim 8 ,
wherein a difference Nxy−Nz between the refractive index Nxy and the refractive index Nz is 0.25 to 0.40.

10 . The magnetic tape cartridge according to claim 8 ,
wherein the magnetic tape further comprises: a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

11 . The magnetic tape cartridge according to claim 8 ,
wherein the total thickness of the magnetic tape is 3.00 μm to 5.30 μm.

12 . The magnetic tape cartridge according to claim 8 ,
wherein the magnetic tape further comprises: a back coating layer including non-magnetic powder and a binding agent on a surface of the non-magnetic support opposite to a surface provided with the magnetic layer.

13 . The magnetic tape cartridge according to claim 8 ,
wherein the center line average surface roughness Ra measured on the surface of the magnetic layer is 1.2 nm to 1.8 nm.

14 . The magnetic tape cartridge according to claim 8 ,
wherein the servo pattern is a timing-based servo pattern.

15 . A magnetic tape apparatus comprising:
a magnetic head; and a magnetic tape, which comprises: a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, wherein a total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer has a servo pattern, a center line average surface roughness Ra measured on a surface of the magnetic layer is equal to or smaller than 1.8 nm, and an absolute value ΔN of a difference between a refractive index Nxy of the magnetic layer, measured in an in-plane direction and a refractive index Nz of the magnetic layer, measured in a thickness direction is 0.25 to 0.40.

16 . The magnetic tape apparatus according to claim 15 ,
wherein a difference Nxy−Nz between the refractive index Nxy and the refractive index Nz is 0.25 to 0.40.

17 . The magnetic tape apparatus according to claim 15 ,
wherein the magnetic tape further comprises: 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 of the non-magnetic support opposite to a surface provided with the magnetic layer.

18 . The magnetic tape apparatus according to claim 15 ,
wherein the total thickness of the magnetic tape is 3.00 μm to 5.30 μm.

19 . The magnetic tape apparatus according to claim 15 ,
wherein the center line average surface roughness Ra measured on the surface of the magnetic layer is 1.2 nm to 1.8 nm.

20 . The magnetic tape apparatus according to claim 15 ,
wherein the servo pattern is a timing-based servo pattern.

Assignees

• Fujifilm Corp

Inventors

• Kasada Norihito

Classifications

• G11B5/845

  in a magnetic field · CPC title

• G11B5/7356

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

• G11B5/733

  characterised by the addition of non-magnetic particles {(base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739)} · CPC title

• G11B5/7085

  non-magnetic abrasive particles · CPC title

• G11B5/70678

  Ferrites · CPC title