US4876117A
Expired / Lapsed
US
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Method and coating transition metal oxide on thin film magnetic disks
Assignee: Domain Technology
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Filing: 1988-02-04
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Granted: 1989-10-24
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Expires: 2008-02-04
Abstract
Abstract Hard magnetic recording disks include a rigid substrate, typically aluminum, ceramic, or glass, having an underlayer thereover, typically being nickel-phosphorus. A ferromagnetic film is formed over the underlayer, and a protective coating layer formed over the ferromagnetic layer. The protective coating layer is a metal oxide formed by applying a liquid metal oxide precursor material over the ferromagnetic layer, and curing the liquid precursor material to leave a metal oxide layer in place. Optionally, a lubricating or carbon layer may be formed over the protective layer.
Inventors
- 👤 Jonathan G. Bornstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:40
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/80; C04B41/81; C04B41/89; C03; C03C; C03C17/00; C03C17/34; C03C17/36; C03C17/3602; C03C17/3613; C03C17/3615; C03C17/3634; C03C17/3649; C03C17/3657; C04B41/009; C04B41/45; C04B41/52; C23; C23C; C23C18/00; C23C18/02; C23C18/12; C23C18/1204; C23C18/1208; C23C18/1216; C23C18/1229; C23C18/1245; C23C18/125; C23C18/1295; G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/84; C04B2111/00; C04B2111/00474; C04B2111/00844; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
96 words
A method for forming a protective coating over the surface of a magnetic recording disk, said method comprising: applying a uniform layer of a liquid metal oxide precursor solution over the surface of the magnetic recording disk, said metal being selected from the group consisting of Groups IVB, VB and VIB of the Periodic Table and aluminum, indium, and tin; and heating the layer on the disk to a temperature in the range from about 100° to 300° C. for a sufficient time to convert the precursor to a hardened layer of the corresponding metal oxide.
Claim 2
Independent Claim
96 words
A method for forming a protective coating over the surface of a magnetic recording disk, said method comprising: applying a uniform layer of a liquid metal oxide precursor solution over the surface of the magnetic recording disk, said metal being selected from the group consisting of Groups IVB, VB and VIB of the Periodic Table and aluminum, indium, and tin; and heating the layer on the disk to a temperature in the range from about 100° to 300° C. for a sufficient time to convert the precursor to a hardened layer of the corresponding metal oxide.
Claim 3
Dependent Claim
36 words
A method as in claim 1, wherein the liquid metal oxide precursor solution is an organic solvent having a metal compound selected from the group consisting of metal alkoxides, metal halides, and metal acetylacetonates dissolved therein.
Claim 4
Dependent Claim
21 words
A method as in claim 1, wherein the metal oxide precursor is aluminum sec-butoxide Al(OC 4 H 9 ) 3 .
Claim 5
Dependent Claim
24 words
A method as in claim 1, wherein the metal is selected from the group consisting of tantalum, titanium, niobium, zirconium, aluminum, hafnium, and vanadium.
Claim 6
Dependent Claim
25 words
A method as in claim 1, wherein the liquid metal oxide precursor solution has a viscosity in the range from about 0.5 to 3 cp.
Claim 7
Dependent Claim
27 words
A method as in claim 5, wherein the liquid metal oxide precursor solution is applied to a thickness in the range from about 50 to 1000 Å.
Claim 8
Dependent Claim
31 words
A method as in claim 6, wherein the liquid metal oxide precursor solution is applied by a process selected from the group consisting of spin coating, dipping, roll coating, and spraying.
Claim 9
Dependent Claim
20 words
A method as in claim 1, wherein the metal oxide precursor is heated in the presence of an acid catalyst.
Claim 10
Dependent Claim
26 words
A method as in claim 1, wherein the metal oxide precursor is tantalum ethoxide (Ta(C 2 H 5 O) 5 ) dissolved in an organic solvent.
Claim 11
Dependent Claim
26 words
A method as in claim 1, wherein the metal oxide precursor material is titanium ethoxide Ti(C 2 H 5 O) 4 dissolved in an organic solvent.
Claim 12
Dependent Claim
24 words
A method as in claim 1, wherein the metal oxide precursor is tantalum chloride (Ta 2 Cl 5 ) dissolved in an organic solvent.
Claim 13
Dependent Claim
26 words
A method as in claim 1, wherein the metal oxide precursor is zirconium n-butoxide (Zr(C 4 H 9 O) 4 ) dissolved in an organic solvent.
Claim 14
Dependent Claim
22 words
A method as in claim 1, wherein the metal oxide precursor is zirconium tetrachloride (ZrCl 4 ) dissolved in an organic solvent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-23 | 1993-04-24 | 1993-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-23 | 1997-04-24 | 1997-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-23 | 2001-04-24 | 2001-10-24 | $7700.00 | Window Closed / Lapsed |