Patent US4769046A successfully refreshed from Google Patents.
US4769046A
Expired / Lapsed
US
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Process for polishing surface of memory hard disc
Assignee: Fujimi Kenmazai Kogyo Co Ltd
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Filing: 1987-08-05
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Granted: 1988-09-06
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Expires: 2007-08-05
Abstract
Abstract A composition for polishing a layer of non-electrolysis nickel plating, an alumite layer or an aluminium substrate in a memory hard disc, the composition comprising water, a polishing agent of aluminium oxide, and a polishing accelerator of one of nickel nitrate and aluminium nitrate, or two compounds, nickel nitrate and aluminium nitrate, or two compounds, nickel sulfate and aluminium nitrate.
Inventors
- 👤 Tetsuji Senda
- 👤 Takashi Baba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:15
CPC Classifications
C; C23; C23F; C23F3/00; C09; C09G; C09G1/00; C09G1/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
In a polishing process comprising polishing the surface of a memory hard disk with a polishing composition applied between the surface of the memory hard disc and the surface of a polishing pad which is slidable on the surface of the memory hard disc, the improvement wherein the surface of the memory hard disc is a non-electrolysis nickel plated surface, an alumite surface, or an aluminum surface, and the polishing composition comprises water, a polishing agent of aluminum oxide, and a polishing accelerator of aluminum nitrate.
Claim 2
Dependent Claim
86 words
In a polishing process comprising polishing the surface of a memory hard disk with a polishing composition applied between the surface of the memory hard disc and the surface of a polishing pad which is slidable on the surface of the memory hard disc, the improvement wherein the surface of the memory hard disc is a non-electrolysis nickel plated surface, an alumite surface, or an aluminum surface, and the polishing composition comprises water, a polishing agent of aluminum oxide, and a polishing accelerator of aluminum nitrate.
Claim 3
Dependent Claim
21 words
A polishing process as set forth in claim 1, wherein the polishing composition contains 1-20% by weight of the polishing accelerator.
Claim 4
Dependent Claim
43 words
A polishing process as set forth in claim 2, wherein the polishing composition contains 2-30% by weight of the polishing agent, and the polishing agent has a mean particle size of 0.7-4.0 μm and a maximum particle size of 20 μm or less.
Claim 5
Dependent Claim
49 words
A polishing process as set forth in claim 3, wherein the polishing agent is α-aluminum oxide prepared by calcining granular boehmite at a temperature of 1,100°-1,200° C. for 2 to 3 hours, crushing relatively large particles into finer particles and separating particles falling within a predetermined particle size distribution.
Claim 6
Dependent Claim
22 words
A polishing process as set forth in claim 1, wherein the non-electrolysis nickel plated surface is a non-electrolysis nickel phosphorus plated surface.
Claim 7
Dependent Claim
22 words
A polishing process as set forth in claim 1, wherein the non-electrolysis nickel plated surface is a non-electrolysis nickel boron plated surface.
Claim 8
Dependent Claim
18 words
A polishing process as set forth in claim 1, wherein the alumite surface is a sulfate alumite surface.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |