US4835909A
Expired / Lapsed
US
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Surface treatment of disk-shaped nickel-plated aluminum substrates
Assignee: BASF SE
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Filing: 1987-08-06
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Granted: 1989-06-06
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Expires: 2007-08-06
Abstract
Abstract Disk-shaped nickel-plated aluminum substrates which are used as bases in the production of magnetic recording disks having a magnetizable metallic layer are surface treated by polishing and texturing.
Inventors
- 👤 Juergen Richter
- 👤 Werner Grau
- 👤 Gerd Maurer
- 👤 Friedrich Domas
- 👤 Werner Loeser
- 👤 Rainer Bender
- 👤 Axel-Ruediger Schulze
- 👤 Kurt Doerr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:44
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/62; G11B5/73; G11B5/739; G11B5/73911; G11B5/73913; G11B5/73917; G11B5/73919
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
161 words
A process for the surface treatment of a disk-shaped nickel-plated aluminum substrate which is suitable as a base for the production of a metallic film disk having a magnetizable cobalt-phosphorus layer, by polishing and texturing the nickel layer to a peak-to-valley height R t from 0.04 to 1.0 μm, an average peak-to-valley height R z of from 0.04 to 0.1 μm and a center line average value R a of from 0.0065 to 0.0095 μm, wherein the nickel-plated aluminum disk is first polished with a polishing agent, in an automatic machine which laps on both sides, with removal of from 2.0 to 4.0 μm of the surface per side, to a center line average value R a of from 0.004 to 0.006 μm, and directly thereafter is textured in the same automatic machine with the use of a polishing agent which has from 3 to 10 times the particle size of that initially used, with the formation of arcuate radial sections.
Claim 2
Dependent Claim
161 words
A process for the surface treatment of a disk-shaped nickel-plated aluminum substrate which is suitable as a base for the production of a metallic film disk having a magnetizable cobalt-phosphorus layer, by polishing and texturing the nickel layer to a peak-to-valley height R t from 0.04 to 1.0 μm, an average peak-to-valley height R z of from 0.04 to 0.1 μm and a center line average value R a of from 0.0065 to 0.0095 μm, wherein the nickel-plated aluminum disk is first polished with a polishing agent, in an automatic machine which laps on both sides, with removal of from 2.0 to 4.0 μm of the surface per side, to a center line average value R a of from 0.004 to 0.006 μm, and directly thereafter is textured in the same automatic machine with the use of a polishing agent which has from 3 to 10 times the particle size of that initially used, with the formation of arcuate radial sections.
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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) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |