Magnetic recording medium having a thin film magnetic layer and a sulfonamide lubricant

• US 5,591,503 A
• Filed: 05/10/1995
• Issued: 01/07/1997
• Est. Priority Date: 05/25/1994
• Status: Expired due to Fees

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Kar, Kishore K., Morgan, Ted A., Pews, R. Garth
• Primary Examiner(s): Resan, Stevan A.
• Application Number:
  US08/438,943
• Time in Patent Office: 608 Days
• Field of Search: 428/694 TP, 428/694 TF, 428/694 BP, 428/694 BF, 428/336, 428/900, 428/694 TC, 428/65.4, 427/131
• US Class Current: 428/835.6
• CPC Class Codes: G11B 5/71 characterised by the lubricant
• CPC Class Codes: G11B 5/725 containing a lubricant , e.g. organic compounds inorganic carbon protective coating G11B5/727
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A magnetic recording medium, comprising a substrate, a magnetic recording lamina and at least one sulfonamide wherein the at least one sulfonamide is present in an amount sufficient to provide desirable tribological properties. A process for lubricating magnetic recording media comprising applying at least one sulfonamide to a surface of the magnetic recording media or incorporating at least one sulfonamide into the lamina of the magnetic recording media.

Claims

1. A magnetic recording medium, comprising a substrate having a thin film magnetic recording lamina deposited thereon, wherein the lamina comprises a magnetic layer and at least one sulfonamide, and wherein the at least one sulfonamide is present in an average thickness of 1 to 1000 å

ngstr oms, and wherein the sulfonamide contains up to 60 carbon atoms and is of formula R₁ --SO₂ NR₂ R₃ wherein R₁ is an unsubstituted alkyl of up to 18 carbons or an aromatic moiety of up to 12 carbons which can be substituted by halo, methyl, ethyl, methoxy, ethoxy, trihalomethyl, trihalomethoxy or polyhaloethoxy and R₂ and R₃ are independently hydrogen or alkyl of up to 20 carbons with the proviso that no more than one of R₂ or R₃ can be hydrogen.

2. The magnetic recording medium of claim 1 wherein R₁ is an unsubstituted alkyl of from 4 to 10 carbons, and R₂ and R₃ are independently methyl, octyl, dodecyl or octadecyl.

3. The magnetic recording medium of claim 1 wherein the aromatic moiety of R₁ can contain one or more nitrogen atoms within a ring.

4. The magnetic recording medium of claim 1 wherein the aromatic moiety of R₁ is phenoxyphenyl, phenyl, naphtyl, biphenyl, quinolinyl, pyridinyl, pyridazinyl or pyrimidinyl.

5. The magnetic recording medium of claim 1 wherein R₁ is a trihalomethyl substituted aromatic moiety, R₂ is n-octyl, and R₃ is n-octyl.

6. The magnetic recording medium of claim 1 wherein at least one sulfonamide is N-dodecylbenzenesulfonamide, N,N'"'"'-di-n-octyl-2,4-bis(2,2,2-trifluoroethoxy) benzenesulfonamide, N,N'"'"'-di-n-octyl-3-trifluoromethylbenzenesulfonamide, N,N'"'"'-di-n-octyl-2,4-diethoxybenzenesulfonamide, N,N'"'"'-di-n-octyl-4-(3-trifluoromethylphenoxy)benzenesulfonamide, N,N'"'"'-di-n-octyl-2,4-dichlorobenzenesulfonamide, N,N'"'"'-di-n-octyl-3,4-difluorobenzenesulfonamide, N,N'"'"'-di-n-octyl-8-quinolinesulfonamide, N,N'"'"'-di-n-octyl-4-phenoxybenzenesulfonamide, N-N'"'"'-di-n-octyl-4-chlorobenzenesulfonamide, N,N'"'"'-di-n-octyl-2-napthalenesulfonamide, N,N'"'"'-di-n-octylbenzenesulfonamide, N,N'"'"'-di-n-octylbutanesulfonamide, N,N'"'"'-di-n-octylpentafluorobenzenesulfonamide, N-dodecyl-3-trifluoromethylbenzenesulfonamide or N-octadecyl-3-trifluoromethylbenzenesulfonamide.

7. The magnetic recording medium of claim 1 wherein the at least one sulfonamide has an average thickness of from about 5 to about 100 å

ngstr oms.

8. The magnetic recording medium of claim 1 wherein the magnetic recording medium is a metal evaporated tape.

9. The magnetic recording medium of claim 1 wherein the medium is selected from the group consisting of rigid disks, ultra high density floppy disks, digital audio tape, 8 mm video tape and super VHS tape.

10. The magnetic recording medium of claim 1 wherein the lamina further comprises a protective overcoat between the magnetic layer and the at least one sulfonamide.

11. The magnetic recording medium of claim 10 wherein the protective overcoat is a carbon overcoat.

12. A process useful for lubricating a magnetic recording medium, comprising applying at least one sulfonamide to a surface of the magnetic recording medium to provide a sulfonamide film having an average thickness of 1 to 1000 å

ngstr oms on the surface, wherein at least one sulfonamide contains up to 60 carbon atoms and is of formula R₁ --SO₂ NR₂ R₃, wherein R₁ is an unsubstituted alkyl of up to 18 carbons or an aromatic moiety of up to 12 carbons which can be substituted by halo, methyl, ethyl, methoxy, ethoxy, trihalomethyl, trihalomethoxy, or polyhaloethoxy and R₂ and R₃ are independently hydrogen or alkyl of up to 20 carbons with the proviso that no more than one of R₂ or R₃ can be hydrogen.

13. The process of claim 12 wherein R₁ is an unsubstituted alkyl of from 4 to 10 carbons, and R₂ and R₃ are independently methyl, octyl, dodecyl, or octadecyl.

14. The process of claim 12 wherein the aromatic moiety of R₁ can contain one or more nitrogen atoms within a ring.

15. The process of claim 12 wherein the aromatic moiety of R₁ is phenoxy phenyl, phenyl, naphthyl, biphenyl, quinolinyl, pyridinyl, pyridazinyl or pyrimidinyl.

16. The process of claim 12 wherein the aromatic moiety of R₁ is phenyl, naphthyl, quinolinyl or phenoxyphenyl.

17. The process of claim 12 wherein at least one sulfonamide is N-dodecylbenzenesulfonamide, N,N'"'"'-di-n-octyl-2,4-bis(2,2,2-trifluoroethoxy)benzenesulfonamide, N,N'"'"'-di-n-octyl-3-trifluoromethylbenzenesulfonamide, N,N'"'"'-di-n-octyl-2,4-diethoxybenzenesulfonamide, N,N'"'"'-di-n-octyl-4-(3-trifluoromethylphenoxy) benzenesulfonamide, N,N'"'"'-di-n-octyl-2,4-dichlorobenzenesulfonamide, N,N'"'"'-di-n-octyl-3,4-difluorobenzenesulfonamide, N,N'"'"'-di-n-octyl-8-quinolinesulfonamide, N,N'"'"'-di-n-octyl-4-phenoxybenzenesulfonamide, N-N'"'"'-di-n-octyl-4-chlorobenzenesulfonamide, N,N'"'"'-di-n-octyl-2-napthalenesulfonamide, N,N'"'"'-di-n-octylbenzenesulfonamide, N,N'"'"'-di-n-octylbutanesulfonamide, N,N'"'"'-di-n-octylpentafluorobenzenesulfonamide, N-dodecyl-3-trifluoromethylbenzenesulfonamide or N-octadecyl-3-trifluoromethylbenzenesulfonamide.