Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

Patent metadata

Field	Value
Publication number	US-11430478-B2
Application number	US-201916727205-A
Country	US
Kind code	B2
Filing date	Dec 26, 2019
Priority date	Dec 28, 2018
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

Provided are a magnetic tape including: a non-magnetic support; a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support, in which an isoelectric point of a surface zeta potential of the magnetic layer is equal to or greater than 5.5, and an isoelectric point of a surface zeta potential of the back coating layer is equal to or greater than 4.5, 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;
a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and
a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support,
wherein the isoelectric point of the surface zeta potential of the magnetic layer is equal to or greater than 5.5, and
the isoelectric point of the surface zeta potential of the back coating layer is greater than or equal to 4.5 and less than or equal to 5.8.

2. The magnetic tape according to claim 1 ,
wherein the isoelectric point of the surface zeta potential of the magnetic layer is 5.5 to 7.0.

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

4. The magnetic tape according to claim 3 ,
wherein the acidic group includes 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 binding agent of the back coating layer is a binding agent including an acidic group.

6. The magnetic tape according to claim 5 ,
wherein the acidic group includes at least one kind of acidic group selected from the group consisting of a sulfonic acid group and a salt thereof.

7. 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.

8. A magnetic tape cartridge comprising:
a magnetic tape, which comprises:
a non-magnetic support;
a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and
a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support,
wherein the isoelectric point of the surface zeta potential of the magnetic layer is equal to or greater than 5.5, and
the isoelectric point of the surface zeta potential of the back coating layer is greater than or equal to 4.5 and less than or equal to 5.8.

9. The magnetic tape cartridge according to claim 8 ,
wherein the isoelectric point of the surface zeta potential of the magnetic layer is 5.5 to 7.0.

10. The magnetic tape cartridge according to claim 8 ,
wherein the binding agent of the magnetic layer and/or the binding agent of the back coating layer is a binding agent including an acidic group.

11. The magnetic tape cartridge according to claim 10 ,
wherein the acidic group includes at least one kind of acidic group selected from the group consisting of a sulfonic acid group and a salt thereof.

12. 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.

13. A magnetic tape apparatus comprising:
a magnetic head; and
a magnetic tape, which comprises:
a non-magnetic support;
a magnetic layer including ferromagnetic powder and a binding agent on one surface side of the non-magnetic support; and
a back coating layer including non-magnetic powder and a binding agent on the other surface side of the non-magnetic support,
wherein the isoelectric point of the surface zeta potential of the magnetic layer is equal to or greater than 5.5, and
the isoelectric point of the surface zeta potential of the back coating layer is greater than or equal to 4.5 and less than or equal to 5.8.

14. The magnetic tape apparatus according to claim 13 ,
wherein the isoelectric point of the surface zeta potential of the magnetic layer is 5.5 to 7.0.

15. The magnetic tape apparatus according to claim 13 ,
wherein the binding agent of the magnetic layer and/or the binding agent of the back coating layer is a binding agent including an acidic group.

16. The magnetic tape apparatus according to claim 15 ,
wherein the acidic group includes at least one kind of acidic group selected from the group consisting of a sulfonic acid group and a salt thereof.

17. The magnetic tape apparatus according to claim 13 ,
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.

Assignees

• Fujifilm Corp

Inventors

• Kasada Norihito

Classifications

• G11B5/7358 Primary

  specially adapted for achieving a specific property, e.g. average roughness [Ra] · CPC title

• G11B5/70689

  Magnetite · CPC title

• G11B5/70 Primary

  on a base layer · CPC title

• G11B5/702

  characterised by the bonding agent · CPC title

• G11B5/78

  Tape carriers · CPC title