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

Patent metadata

Field	Value
Publication number	US-11468911-B2
Application number	US-201916658565-A
Country	US
Kind code	B2
Filing date	Oct 21, 2019
Priority date	Oct 22, 2018
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

The magnetic tape includes a non-magnetic support; a non-magnetic layer including a non-magnetic powder and a binding agent on the non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic layer, in which a total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μm, an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5, the magnetic layer includes an oxide abrasive, and an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm.

First claim

What is claimed is:

1. A magnetic tape comprising:
a non-magnetic support;
a non-magnetic layer including a non-magnetic powder and a binding agent on the non-magnetic support; and
a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic layer,
wherein a total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μm,
an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5,
the magnetic layer includes an oxide abrasive, and
an average particle diameter of the oxide abrasive obtained from a secondary ion image obtained by irradiating the surface of the magnetic layer with a focused ion beam is 0.04 μm to 0.08 μm.

2. The magnetic tape according to claim 1 ,
wherein the isoelectric point is 5.5 to 7.0.

3. The magnetic tape according to claim 1 ,
wherein the magnetic layer includes a binding agent having an acidic group.

4. The magnetic tape according to claim 3 ,
wherein the acidic group is at least one kind of acidic group selected from the group consisting of a sulfonic acid group and a salt thereof.

5. The magnetic tape according to claim 1 ,
wherein the oxide abrasive is an alumina powder.

6. The magnetic tape according to claim 2 ,
wherein the oxide abrasive is an alumina powder.

7. The magnetic tape according to claim 3 ,
wherein the oxide abrasive is an alumina powder.

8. The magnetic tape according to claim 4 ,
wherein the oxide abrasive is an alumina powder.

9. The magnetic tape according to claim 1 ,
wherein the total thickness of the non-magnetic layer and the magnetic layer is 0.15 μm to 0.60 μm.

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

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

12. The magnetic tape cartridge according to claim 11 ,
wherein the isoelectric point is 5.5 to 7.0.

13. The magnetic tape cartridge according to claim 11 ,
wherein the magnetic layer includes a binding agent having an acidic group.

14. The magnetic tape cartridge according to claim 13 ,
wherein the acidic group is at least one kind of acidic group selected from the group consisting of a sulfonic acid group and a salt thereof.

15. The magnetic tape cartridge according to claim 11 ,
wherein the oxide abrasive is an alumina powder.

16. A magnetic tape apparatus comprising:
the magnetic tape according to claim 1 ; and
a magnetic head.

17. The magnetic tape apparatus according to claim 16 ,
wherein the isoelectric point is 5.5 to 7.0.

18. The magnetic tape apparatus according to claim 16 ,
wherein the magnetic layer includes a binding agent having an acidic group.

19. The magnetic tape apparatus according to claim 18 ,
wherein the acidic group is at least one kind of acidic group selected from the group consisting of a sulfonic acid group and a salt thereof.

20. The magnetic tape apparatus according to claim 16 ,
wherein the oxide abrasive is an alumina powder.

Assignees

• Fujifilm Corp

Inventors

• Iwamoto Takahiro
• Kasada Norihito

Classifications

• G11B5/78

  Tape carriers · CPC title

• G11B5/702

  characterised by the bonding agent · CPC title

• G11B5/70

  on a base layer · CPC title

• G11B23/041

  Details · CPC title

• G11B5/71

  characterised by the lubricant · CPC title