US4816119A
Expired / Lapsed
US
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Process for production of magnetic media
Assignee: Maxtor Corp
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Filing: 1987-09-04
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Granted: 1989-03-28
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Expires: 2007-09-04
Abstract
Abstract This invention comprises the use, during the plating processing of thin-film magnetic recording media, of an oxidizing treatment immediately preceding the electroplating of the magnetic layer. This oxidizing treatment can be controlled to produce desired high levels of coercive force and low levels of media noise.
Inventors
- 👤 Gary C. Rauch
- 👤 Young David J.
- 👤 Earl R. C. Johns
- 👤 Robert L. Stone
- 👤 Carolyn A. Messinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:44
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/858; Y; Y10; Y10S; Y10S205/00; Y10S205/922
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
37 words
A process for the production of magnetic recording media comprising the steps of: oxidizing the surface of a layer of an amorphous substrate, and depositing a layer of magnetic material on the oxidized surface of the substrate.
Claim 2
Dependent Claim
37 words
A process for the production of magnetic recording media comprising the steps of: oxidizing the surface of a layer of an amorphous substrate, and depositing a layer of magnetic material on the oxidized surface of the substrate.
Claim 3
Dependent Claim
35 words
The process of claim 1 wherein the surface of the substrate is oxidized by appication of oxidizing treatments selected from the group consisting of exposure to oxygen, acid baths, hydrogen peroxide baths and electrolytic baths.
Claim 4
Dependent Claim
15 words
The method of claim 2 wherein the magnetic material is electrolytically deposited on the substrate.
Claim 5
Dependent Claim
37 words
The method of claim 3 wherein the oxidizing treatment is an electrolytic anodic treatment in a bath of sulfuric acid for from 0.1 to 900% seconds at a current flow of from 0.014 to 14 amps/sq. ft.
Claim 6
Dependent Claim
27 words
The method of claim 4 wherein said anodic treatment is for 15 to 30 seconds at about 0.14 amps/ft. 2 and said bath is 7% sulfuric acid.
Claim 7
Dependent Claim
19 words
The process of claim 3 wherein the oxidizing treatment is exposure to air for from 0.1 to 10 days.
Claim 8
Dependent Claim
21 words
The process of claim 3 when the oxidizing treatment is exposure to sulfuric acid bath for from 2 to 15 minutes.
Claim 9
Dependent Claim
15 words
The process of claim 7 wherein the exposure is for from 5 to 15 minutes.
Claim 10
Dependent Claim
24 words
The process of claim 3 wherein the oxidizing treatment is exposure to a nitric acid bath for from 0.1 minutes to about 5 minutes.
Claim 11
Dependent Claim
24 words
The process of claim 3 wherein the oxidizing treatment is exposure to a 0.1 molar nitric acid bath for from 0.5 to 5.0 minutes.
Claim 12
Dependent Claim
25 words
The process of claim 3 wherein the oxidizing treatment is exposure to a bath of at least 0.1% hydrogen peroxide for at least one minute.
Claim 13
Dependent Claim
21 words
The process of any one of claims 1 through 11 wherein the substrate is comprised of a layer of Ni-P material.
Claim 14
Dependent Claim
13 words
The process of claim 12 wherein the magnetic material is a Co-Ni-P material.
Claim 15
Dependent Claim
18 words
The process of any one of claims 1 through 11 wherein the magnetic material is a Co-Ni-P material.
Claim 16
Dependent Claim
17 words
The method of claim 2 wherein the magnetic material is deposited on the substrate by electroless deposition.
Claim 17
Dependent Claim
37 words
The method of claim 15 wherein the oxidizing treatment is an anodic treatment in a bath of sulfuric acid for from 0.1 to 900 seconds at a current flow of from 0.014 to 14 amps/ft. 2 .
Claim 18
Dependent Claim
27 words
The method of claim 15 wherein said anodic treatment is for 15 to 30 seconds at about 0.14 amps/ft. 2 and said bath is 7% sulfuric acid.
Claim 19
Dependent Claim
19 words
The process of claim 15 wherein the oxidizing treatment is exposure to air for from 0.1 to 10 days.
Claim 20
Dependent Claim
21 words
The process of claim 15 wherein the oxidizing treatment is exposure to sulfuric acid bath for from 2 to 15 minutes.
Claim 21
Dependent Claim
24 words
The process of claim 15 wherein the oxidizing treatment is exposure to a nitric acid bath for from 0.1 minutes to about 5 minutes.
Claim 22
Dependent Claim
24 words
The process of claim 15 wherein the oxidizing treatment is exposure to a 0.1 molar nitric acid bath for from 0.5 to 5.0 minutes.
Claim 23
Dependent Claim
25 words
The process of claim 15 wherein the oxidizing treatment is exposure to a bath of at least 0.1% hydrogen peroxide for at least one minute.
Claim 24
Dependent Claim
21 words
The process of any one of claims 15 through 22 wherein the substrate is comprised of a layer of Ni-P material.
Claim 25
Dependent Claim
16 words
The process of any one of claims 15-22 wherein the magnetic material is a Co-Ni-P material.
Claim 26
Dependent Claim
13 words
The process of claim 24 wherein the substrate material is a Ni-P material.
References Cited (Backward Citations)
US4390562A
Cited
US4581109A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-27 | 1992-09-26 | 1993-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-27 | 1996-09-26 | 1997-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-27 | 2000-09-26 | 2001-03-28 | $7700.00 | Window Closed / Lapsed |