Patent US4929257A successfully refreshed from Google Patents.
US4929257A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Abrasive composition and process for polishing
Assignee: Yamaguchi Seiken Kogyo Co Ltd
•
Filing: 1989-03-30
•
Granted: 1990-05-29
•
Expires: 2009-03-30
Abstract
Abstract An abrasive composition comprising: an aluminous abrasive, preferably having an average particle size of 0.5-10 mu m and a concentration of 1 to 25% by weight; nickel sulfamate and/or sulfate, preferably having a concentration of 0.5 to 10% by weight; magnesium nitrate, preferably having a concentration of 0.1 to 12% by weight and water, the composition preferably having a pH of 4 to 7. This abrasive composition produces a superior effect, particularly a reduction of protrusions and pits and deep scratches when used for polishing an aluminum-based substrate for a magnetic recording disc.
Inventors
- 👤 Kunihiro Miyazaki
- 👤 Ken Ishitobi
- 👤 Yosinobu Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:34
CPC Classifications
B; B24; B24D; B24D3/00; B24D3/02; C; C09; C09K; C09K3/00; C09K3/14; C09K3/1454; C09K3/1463; C23; C23F; C23F3/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
38 words
A weak acid or neutral abrasive composition comprising an alpha alumina, a polishing accelerator of nickel sulfamate and/or sulfate, a surface modifying agent of about 0.1 to about 12% by weight of the composition magnesium nitrate, and water.
Claim 2
Dependent Claim
38 words
A weak acid or neutral abrasive composition comprising an alpha alumina, a polishing accelerator of nickel sulfamate and/or sulfate, a surface modifying agent of about 0.1 to about 12% by weight of the composition magnesium nitrate, and water.
Claim 3
Dependent Claim
16 words
A composition according to claim 1, wherein the composition has a pH of 4 to 7.
Claim 4
Dependent Claim
26 words
A composition according to claim 1, wherein the nickel sulfamate and/or sulfate is contained in an amount of 0.5% to 10% by weight of the composition.
Claim 5
Dependent Claim
36 words
A composition according to claim 1, wherein the alpha alumina is contained in an amount of 1% to 25% by weight of the composition and has an average particle size of 0.5 μm to 10 μm.
Claim 6
Dependent Claim
23 words
A composition according to claim 1, further comprising a crystalline cellulose in an amount of up to 1% by weight of the composition.
Claim 7
Dependent Claim
62 words
A composition according to claim 1, for polishing an aluminum-based magnetic-recording-disc substrate, wherein the alpha alumina has an average particle size of 0.5 μm to 10 μm and is contained in an amount of 1% to 25% by weight of the composition, and the nickel sulfamate and/or sulfate is contained in an amount of 0.5% to 10% by weight of the composition.
Claim 8
Dependent Claim
22 words
A composition according to claim 6, further comprising crystalline cellulose in an amount of up to 1% by weight of the composition.
Claim 9
Dependent Claim
49 words
A process for polishing a workpiece comprising contacting said workpiece with a weak acid or neutral abrasive composition comprising an alpha alumina, a polishing accelerator of nickel sulfamate and/or sulfate, a surface modifying agent of about 0.1 to about 12% by weight of the composition magnesium nitrate, and water.
Claim 10
Dependent Claim
49 words
A process for polishing a workpiece comprising contacting said workpiece with a weak acid or neutral abrasive composition comprising an alpha alumina, a polishing accelerator of nickel sulfamate and/or sulfate, a surface modifying agent of about 0.1 to about 12% by weight of the composition magnesium nitrate, and water.
Claim 11
Dependent Claim
24 words
A process according to claim 8, wherein the workpiece is a substrate for a magnetic recording disc, made of aluminum or an aluminum alloy.
Claim 12
Dependent Claim
13 words
A process according to claim 9, wherein the substrate is plated with nickel-phosphine.
Claim 13
Dependent Claim
11 words
A process according to claim 9, wherein the substrate is anodized.
Claim 14
Dependent Claim
17 words
A process according to claim 8, wherein the the composition has a pH of 4 to 7.
Claim 15
Dependent Claim
26 words
A process according to claim 8, wherein the nickel sulfamate and/or sulfate is contained in an amount of 0.5% to 10% by weight of the composition.
Claim 16
Dependent Claim
36 words
A process according to claim 8, wherein the aluminous abrasive is contained in an amount of 1% to 25% by weight of the composition and has an average particle size of 0.5 μm to 10 μm.
Claim 17
Dependent Claim
26 words
A process according to claim 8, wherein the abrasive composition further comprises crystalline cellulose in an amount of up to 1% by weight of the composition.
References Cited (Backward Citations)
US4226623A
Cited
US4358295A
Cited
US4451269A
Cited
JPS61278587A
Cited
US4696697A
Cited
US4705566A
Cited
US4645561A
Cited
US4769073A
Cited
US4853000A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-28 | 1993-11-27 | 1994-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-28 | 1997-11-27 | 1998-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-28 | 2001-11-27 | 2002-05-29 | $7700.00 | Window Closed / Lapsed |