Protective layer for mitigating protruding defects in magnetic tape recording media

Patent metadata

Field	Value
Publication number	US-10395684-B2
Application number	US-201615158447-A
Country	US
Kind code	B2
Filing date	May 18, 2016
Priority date	May 18, 2016
Publication date	Aug 27, 2019
Grant date	Aug 27, 2019

Abstract

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

First claim

What is claimed is:

1. A magnetic recording medium, comprising:
an underlayer;
a magnetic layer above the underlayer, the magnetic layer including a first magnetic material and particulates; and
a protective layer above the magnetic layer, the protective layer including a second material, wherein the second material is magnetic, 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.

2. The magnetic recording medium as recited in claim 1 , wherein a total thickness of the magnetic and protective layers is a design magnetic thickness of the magnetic recording medium.

3. The magnetic recording medium as recited in claim 1 , wherein the second material is nonmagnetic.

4. The magnetic recording medium as recited in claim 1 , wherein the protective layer is constructed of a material that does not contain the particulates.

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

6. The magnetic recording medium as recited in claim 1 , wherein the protective layer includes a lubricating material.

7. A magnetic recording medium, comprising:
an underlayer;
a magnetic layer above the underlayer, the magnetic layer including a first magnetic material and particulates; and
a protective layer above the magnetic layer, the protective layer including a second material, wherein a thickness of the protective layer is at least 10% of a total thickness of the magnetic recording medium,
wherein at least some of the particulates of the magnetic layer protrude completely through the protective layer.

8. The magnetic recording medium as recited in claim 1 , wherein the first magnetic material in the magnetic layer includes barium ferrite.

9. The magnetic recording medium as recited in claim 1 , wherein the second material in the protective layer includes barium ferrite.

10. The magnetic recording medium as recited in claim 1 , wherein the particulates include aluminum oxide.

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

12. The method as recited in claim 11 , comprising adding a lubricant on an outer surface of the protective layer.

13. The method as recited in claim 11 , wherein the protective layer is viscous when formed.

14. The method as recited in claim 11 , wherein at least one of the layers of the magnetic recording medium is formed using extrusion.

15. The method as recited in claim 11 , wherein at least two layers of the magnetic recording medium are co-extruded, and thereby cure together.

16. The magnetic recording medium as recited in claim 1 , wherein some of the particulates protrude beyond and are thereby exposed along an upper surface of the protective layer.

17. The method as recited in claim 11 , wherein a composition of the protective layer is different than a composition of the magnetic layer.

18. The method as recited in claim 11 , wherein a total thickness of the magnetic and protective layers is a design magnetic thickness of the magnetic recording medium.

Assignees

• IBM

Inventors

• Biskeborn Robert G
• Lo Calvin S

Classifications

• G11B5/716

  characterised by two or more magnetic layers · CPC title

• G11B5/708 Primary

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

• G11B5/7305

  Physics · mapped topic

• G11B5/72

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

• G11B5/737

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