Magnetic tape including characterized magnetic layer

Patent metadata

Field	Value
Publication number	US-10497388-B2
Application number	US-201715624792-A
Country	US
Kind code	B2
Filing date	Jun 16, 2017
Priority date	Jun 23, 2016
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

A magnetic tape is provided having a total thickness of the non-magnetic and magnetic layers of less than or equal to 0.60 μm. The C—H derived C concentration calculated from the C—H peak area ratio of C1s spectra by ESCA on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is greater than or equal to 45 atom %. The full widths at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before and after vacuum heating with respect to the magnetic tape are respectively greater than 0 nm and less than or equal to 7.0 nm, and the difference between a spacing measured after the vacuum heating and a spacing measured before the vacuum heating is greater than 0 nm and less than or equal to 8.0 nm.

First claim

What is claimed is:

1. A magnetic tape comprising:
a non-magnetic support;
a non-magnetic layer including non-magnetic powder and a binder on the non-magnetic support; and
a magnetic layer including ferromagnetic powder and a binder on the non-magnetic layer,
wherein the total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μm,
the magnetic layer includes one or more components selected from the group consisting of fatty acid and fatty acid amide, and fatty acid ester,
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 %,
a full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before performing vacuum heating with respect to the magnetic tape, is greater than 0 nm and equal to or smaller than 7.0 nm,
a full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape, is greater than 0 nm and equal to or smaller than 7.0 nm, and
a difference S after −S before between a spacing S after measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape and a spacing S before measured by optical interferometry regarding the surface of the magnetic layer before performing the vacuum heating with respect to the magnetic tape, is greater than 0 nm and equal to or smaller than 8.0 nm.

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

3. The magnetic tape according to claim 1 ,
wherein the C—H derived C concentration is in a range of 60 to 80 atom %.

4. The magnetic tape according to claim 1 ,
wherein the difference S after −S before is greater than 0 nm and equal to or smaller than 7.0 nm.

5. The magnetic tape according to claim 1 ,
wherein the difference S after −S before is 2.0 nm to 7.0 nm.

6. The magnetic tape according to claim 1 ,
wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before performing vacuum heating with respect to the magnetic tape, is greater than 0 nm and equal to or smaller than 5.0 nm.

7. The magnetic tape according to claim 1 ,
wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape, is greater than 0 nm and equal to or smaller than 5.0 nm.

8. The magnetic tape according to claim 2 ,
wherein the difference S after −S before is greater than 0 nm and equal to or smaller than 7.0 nm.

9. The magnetic tape according to claim 2 ,
wherein the difference S after −S before is 2.0 nm to 7.0 nm.

10. The magnetic tape according to claim 2 ,
wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before performing vacuum heating with respect to the magnetic tape, is greater than 0 nm and equal to or smaller than 5.0 nm.

11. The magnetic tape according to claim 2 ,
wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape, is greater than 0 nm and equal to or smaller than 5.0 nm.

12. The magnetic tape according to claim 3 ,
wherein the difference S after −S before is greater than 0 nm and equal to or smaller than 7.0 nm.

13. The magnetic tape according to claim 3 ,
wherein the difference S after −S before is 2.0 nm to 7.0 nm.

14. The magnetic tape according to claim 3 ,
wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before performing vacuum heating with respect to the magnetic tape, is greater than 0 nm and equal to or smaller than 5.0 nm.

15. The magnetic tape according to claim 3 ,
wherein the full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer after performing the vacuum heating with respect to the magnetic tape, is greater than 0 nm and equal to or smaller than 5.0 nm.

16. The magnetic tape according to claim 1 ,
wherein the total thickness of the non-magnetic layer and the magnetic layer is 0.20 μm to 0.60 μm.

17. The magnetic tape according to claim 1 ,
wherein the magnetic layer includes a non-magnetic filler.

18. The magnetic tape according to claim 9 ,
wherein the non-magnetic filler is colloidal particles.

19. The magnetic tape according to claim 10 ,
wherein the non-magnetic filler is colloidal particles.

Assignees

• Fujifilm Corp

Inventors

• Ozawa Eiki
• Kasada Norihito
• Kurokawa Takuto

Classifications

• G11B5/71

  characterised by the lubricant · CPC title

• G11B5/712

  characterised by the surface treatment or coating of magnetic particles · CPC title

• G11B5/78 Primary

  Tape carriers · CPC title

• G11B5/00817

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

• G11B5/70

  on a base layer · CPC title