Protective layer for mitigating protruding defects in magnetic tape recording media

Patent metadata

Field	Value
Publication number	US-11488629-B2
Application number	US-201916447706-A
Country	US
Kind code	B2
Filing date	Jun 20, 2019
Priority date	May 18, 2016
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A method for forming a magnetic recording medium according to one embodiment includes forming a magnetic layer above an underlayer. The magnetic layer includes a first magnetic material and particulates. A protective layer is formed above the magnetic layer, the protective layer including a second material. A method for forming a magnetic recording medium according to another embodiment includes forming a first nonmagnetic layer above a base film. The first nonmagnetic layer has first nonmagnetic particles. A second nonmagnetic layer is formed above the first nonmagnetic layer, the second nonmagnetic layer having second nonmagnetic particles. A magnetic layer is formed above the second nonmagnetic layer, the magnetic layer including a magnetic material.

First claim

What is claimed is:

1. A method for forming a magnetic recording medium, the method comprising:
forming a magnetic layer above an underlayer, the magnetic layer including a first magnetic material and particulates; and
forming a protective layer above the magnetic layer, the protective layer including a second material,
wherein a thickness of the protective layer is such that at least some of the particulates of the magnetic layer protrude completely through the protective layer and are exposed along an upper surface of the protective layer.

2. The method as recited in claim 1 , wherein the second material is magnetic, wherein a composition of the protective layer is different than a composition of the magnetic layer.

3. The method as recited in claim 2 , wherein a total thickness of the magnetic and protective layers is a design magnetic thickness of the magnetic recording medium.

4. The method as recited in claim 1 , wherein the second material is nonmagnetic.

5. The method as recited in claim 1 , wherein the protective layer is constructed of a material that does not contain the particulates.

6. The method as recited in claim 1 , wherein the protective layer is an outermost layer of the magnetic recording medium.

7. The method as recited in claim 1 , wherein the protective layer includes a lubricating material.

8. The method as recited in claim 1 , wherein a thickness of the protective layer is at least 10% of a total thickness of the magnetic recording medium.

9. The method as recited in claim 1 , wherein the first magnetic material in the magnetic layer includes barium ferrite.

10. The method as recited in claim 1 , wherein the second material in the protective layer includes barium ferrite.

11. The method as recited in claim 1 , wherein the particulates include aluminum oxide.

12. A method for forming a magnetic recording medium, the method comprising:
forming a magnetic layer above an underlayer, the magnetic layer including a first magnetic material and particulates; and
forming a protective layer above the magnetic layer,
wherein a composition of the protective layer is different than a composition of the magnetic layer,
wherein at least some of the particulates of the magnetic layer protrude completely through the protective layer, and are exposed along an upper surface of the protective layer, and
wherein a thickness of the protective layer is at least 10% of a total thickness of the magnetic recording medium.

13. The method as recited in claim 12 , wherein the protective layer is constructed of a material that does not contain the particulates.

14. A method for forming a magnetic recording medium, the method comprising:
forming a magnetic layer above an underlayer
forming a protective layer above the magnetic layer, the magnetic layer having a first magnetic material and particulates, the protective layer including a second material,
wherein at least some of the particulates of the magnetic layer protrude through the protective layer and are exposed along an upper surface of the protective layer.

15. The method as recited in claim 14 , wherein the protective layer is constructed of a material that does not contain the particulates.

16. The method as recited in claim 14 , wherein the protective layer is an outermost layer of the magnetic recording medium.

17. The method as recited in claim 14 , wherein the protective layer includes a lubricating material.

18. The method as recited in claim 14 , wherein the first magnetic material in the magnetic layer includes barium ferrite.

19. The method as recited in claim 14 , wherein the at least some of the particulates of the magnetic layer are exposed above an upper surface of the protective layer.

Assignees

• IBM

Inventors

• Biskeborn Robert G
• Lo Calvin S

Classifications

• G11B5/716

  characterised by two or more magnetic layers · CPC title

• G11B5/7368

  Non-polymeric layer under the lowermost magnetic recording layer (base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739) · CPC title

• G11B5/708 Primary

  characterised by addition of non-magnetic particles to the layer · CPC title

• G11B5/737

  Physical structure of underlayer, e.g. texture · CPC title

• G11B5/72

  Protective coatings, e.g. anti-static {or antifriction} · CPC title