US4737419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overcoat for particulate magnetic recording disk
Assignee: International Business Machines Corp
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Filing: 1986-02-13
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Granted: 1988-04-12
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Expires: 2006-02-13
Abstract
Abstract Carbon is sputter-deposited as a protective overcoat on the coating of a magnetic recording disk of the type in which the coating includes magnetic particles dispersed in an organic binder. The carbon film exhibits excellent durability and lubricity, thereby eliminating the need to incorporate alumina or other load-bearing particles into the magnetic coating, and eliminating the need for a liquid lubricant on the disk surface.
Inventors
- 👤 Magdalena M. Hilden
- 👤 Jia-Kuen J. Lee
- 👤 Anthony W. Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:10
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/842; G11B5/62; G11B5/72; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
47 words
In a magnetic recording disk of the type in which a coating of magnetic particles dispersed in an organic binder is formed directly on a substrate, an improvement comprising a carbon layer formed on and adhered to the coating, the carbon layer having an essentially amorphous structure.
Claim 2
Dependent Claim
47 words
In a magnetic recording disk of the type in which a coating of magnetic particles dispersed in an organic binder is formed directly on a substrate, an improvement comprising a carbon layer formed on and adhered to the coating, the carbon layer having an essentially amorphous structure.
Claim 3
Dependent Claim
18 words
The improved magnetic recording disk according to claim 1, wherein the disk coating includes load-bearing particles dispersed therein.
Claim 4
Dependent Claim
19 words
The improved magnetic recording disk according to claim 1 wherein the carbon layer further comprises a sputter-deposited carbon film.
Claim 5
Dependent Claim
38 words
A magnetic recording disk comprising a substrate, a coating on the substrate of magnetic particles dispersed in an organic binder, and a protective carbon film sputter-deposited directly onto the coating, the carbon film having an essentially amorphous structure.
Claim 6
Dependent Claim
38 words
A magnetic recording disk comprising a substrate, a coating on the substrate of magnetic particles dispersed in an organic binder, and a protective carbon film sputter-deposited directly onto the coating, the carbon film having an essentially amorphous structure.
Claim 7
Dependent Claim
14 words
The magnetic recording disk according to claim 4 wherein the coating includes load-bearing particles.
Claim 8
Dependent Claim
77 words
In a process for the fabrication of a magnetic recording disk, the process being of the type which includes preparing a dispersion of magnetic particles in an organic binder, applying the binder over a suitable substrate to form a magnetic coating and curing the coating, an improvement to the process comprising forming an adherent layer of carbon having an essentially amorphous structure directly onto the cured coating, whereby the durability and lubricity of the disk are enhanced.
Claim 9
Dependent Claim
77 words
In a process for the fabrication of a magnetic recording disk, the process being of the type which includes preparing a dispersion of magnetic particles in an organic binder, applying the binder over a suitable substrate to form a magnetic coating and curing the coating, an improvement to the process comprising forming an adherent layer of carbon having an essentially amorphous structure directly onto the cured coating, whereby the durability and lubricity of the disk are enhanced.
Claim 10
Dependent Claim
26 words
The improved process according to claim 6 wherein the step of forming a layer of carbon further comprises the step of sputter-depositing a film of carbon.
Claim 11
Dependent Claim
81 words
A process for fabricating a magnetic recording disk comprising: providing a substrate; providing an organic binder containing polymers; mixing magnetic particles into the binder; applying the binder having magnetic particles dispersed therein onto the substrate as a coating; curing the coating to cross-link the polymers and harden the coating; and applying by sputter-deposition a thin protective film of carbon having an essentially amorphous structure directly onto the cured coating, whereby the durability and lubricity of the magnetic recording disk are enhanced.
Claim 12
Dependent Claim
81 words
A process for fabricating a magnetic recording disk comprising: providing a substrate; providing an organic binder containing polymers; mixing magnetic particles into the binder; applying the binder having magnetic particles dispersed therein onto the substrate as a coating; curing the coating to cross-link the polymers and harden the coating; and applying by sputter-deposition a thin protective film of carbon having an essentially amorphous structure directly onto the cured coating, whereby the durability and lubricity of the magnetic recording disk are enhanced.
Claim 13
Dependent Claim
28 words
The process according to claim 8 including the steps of, prior to applying the thin film of carbon, buffing, washing, and burnishing the cured coating on the substrate.
References Cited (Backward Citations)
US4503125A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |