Magnetic tape having characterized magnetic layer and hexagonal ferrite powder

Patent metadata

Field	Value
Publication number	US-10477072-B2
Application number	US-201715620916-A
Country	US
Kind code	B2
Filing date	Jun 13, 2017
Priority date	Jun 22, 2016
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A magnetic tape is provided in which ferromagnetic powder included in a magnetic layer is ferromagnetic hexagonal ferrite powder having an activation volume less than or equal to 1,600 nm 3 . The magnetic layer includes one or more components selected from a fatty acid and a fatty acid amide, and an abrasive. The C—H derived C concentration calculated from the C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is greater than or equal to 45 atom %. Also, the tilt cos θ of the ferromagnetic hexagonal ferrite powder with respect to the surface of the magnetic layer acquired by cross section observation performed by using a scanning transmission electron microscope is 0.85 to 1.00.

First claim

What is claimed is:

1. A magnetic tape comprising:
a non-magnetic support; and
a magnetic layer including ferromagnetic powder and a binder on the non-magnetic support,
wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm 3 ,
the magnetic layer includes one or more components selected from the group consisting of fatty acid and fatty acid amide, and an abrasive,
a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is equal to or greater than 45 atom %, and
a tilt cos θ of the ferromagnetic hexagonal ferrite powder with respect to the surface of the magnetic layer acquired by cross section observation performed by using a scanning transmission electron microscope is 0.85 to 1.00.

2. The magnetic tape according to claim 1 ,
wherein the C—H derived C concentration is 45 atom % to 80 atom %.

3. The magnetic tape according to claim 1 ,
wherein the C—H derived C concentration is 50 atom % to 80 atom %.

4. The magnetic tape according to claim 1 ,
wherein the activation volume of the ferromagnetic hexagonal ferrite powder is 800 nm 3 to 1,600 nm 3 .

5. The magnetic tape according to claim 2 ,
wherein the activation volume of the ferromagnetic hexagonal ferrite powder is 800 nm 3 to 1,600 nm3.

6. The magnetic tape according to claim 3 ,
wherein the activation volume of the ferromagnetic hexagonal ferrite powder is 800 nm 3 to 1,600 nm 3 .

7. The magnetic tape according to claim 1 ,
wherein the abrasive includes alumina powder.

8. The magnetic tape according to claim 1 ,
wherein the magnetic layer further includes a polyester chain-containing compound having a weight-average molecular weight of 1,000 to 80,000.

9. The magnetic tape according to claim 2 ,
wherein the magnetic layer further includes a polyester chain-containing compound having a weight-average molecular weight of 1,000 to 80,000.

10. The magnetic tape according to claim 3 ,
wherein the magnetic layer further includes a polyester chain-containing compound having a weight-average molecular weight of 1,000 to 80,000.

11. The magnetic tape according to claim 4 ,
wherein the magnetic layer further includes a polyester chain-containing compound having a weight-average molecular weight of 1,000 to 80,000.

12. The magnetic tape according to claim 5 ,
wherein the magnetic layer further includes a polyester chain-containing compound having a weight-average molecular weight of 1,000 to 80,000.

13. The magnetic tape according to claim 6 ,
wherein the magnetic layer further includes a polyester chain-containing compound having a weight-average molecular weight of 1,000 to 80,000.

14. The magnetic tape according to claim 7 ,
wherein the magnetic layer further includes a polyester chain-containing compound having a weight-average molecular weight of 1,000 to 80,000.

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

16. The magnetic tape according to claim 15 ,
wherein magnetic layer and the non-magnetic layer respectively include one or more components selected from the group consisting of fatty acid and fatty acid amide.

Assignees

• Fujifilm Corp

Inventors

• Kasada Norihito

Classifications

• H04N1/405

  Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels · CPC title

• G11B5/00813

  magnetic tapes · CPC title

• H04N1/4053

  with threshold modulated relative to input image data or vice versa · CPC title

• G11B5/70605 Primary

  metals or alloys · CPC title

• G11B5/78

  Tape carriers · CPC title