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US4472173A
Expired / Lapsed
US
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Ceramic-coated corundum abrasive grain
Assignee: Dynamit Nobel AG
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Filing: 1982-11-09
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Granted: 1984-09-18
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Expires: 2002-11-09
Abstract
Abstract In corundum abrasive grain which is ceramically coated with ground frit, a binder and fine grain highly abrasive material for the purpose of improving adhesion of the abrasive grain in its processing to resin-bonded abrasives and their use in wet grinding. The fine grain material forms from 1 to 5 weight percent of the untreated corundum grain and ranges in size from 10 to 50 microns, which corresponds to from 1 to 10 percent of the average diameter of the initial grain.
Inventors
- 👤 Klaus Bruning
- 👤 Gerhard Rehfeld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:48
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/14; C09K3/1436
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
69 words
A corundum abrasive grain having a ceramic coating of from 0.25 to 2 weight percent based on the weight of the untreated grain, said coating comprising finely ground frit, a binder and from 1 to 5 weight percent of a highly abrasive fine grain material ranging in size from 10 to 50 microns, which corresponds to from 1 to 10 percent of the average diameter of the initial grain.
Claim 2
Dependent Claim
69 words
A corundum abrasive grain having a ceramic coating of from 0.25 to 2 weight percent based on the weight of the untreated grain, said coating comprising finely ground frit, a binder and from 1 to 5 weight percent of a highly abrasive fine grain material ranging in size from 10 to 50 microns, which corresponds to from 1 to 10 percent of the average diameter of the initial grain.
Claim 3
Dependent Claim
21 words
The corundum abrasive grain of claim 1, wherein the fine grain material in the coating is highly abrasive high-purity synthetic corundum.
Claim 4
Dependent Claim
20 words
The corundum abrasive grain of claim 1, wherein the fine grain material in the coating is highly abrasive silicon carbide.
Claim 5
Dependent Claim
12 words
The corundum abrasive of claim 1 wherein the binder is sodium silicate.
Claim 6
Dependent Claim
21 words
The corundum abrasive of claim 1 wherein the fine grain in the coating has a particle size of 10μ to 50μ.
Claim 7
Dependent Claim
19 words
The corundum abrasive of claim 1 wherein the frit has a particle size of up to about 100 microns.
Claim 8
Independent Claim
56 words
A method for preparing a corundum abrasive grain comprising mixing the corundum abrasive grain with finely ground frit, a solution of the binder, and the highly abrasive fine grain material, drying the mixture, and heating the dried mixture to a temperature above the fusing temperature of the frit and then cooling to form a ceramic coating.
Claim 9
Independent Claim
56 words
A method for preparing a corundum abrasive grain comprising mixing the corundum abrasive grain with finely ground frit, a solution of the binder, and the highly abrasive fine grain material, drying the mixture, and heating the dried mixture to a temperature above the fusing temperature of the frit and then cooling to form a ceramic coating.
Claim 10
Dependent Claim
32 words
The method of claim 7 wherein the mixture is dried at 120° C. and thereafter the dried mixture heated to about 950° C. for about 8 minutes to form the ceramic coating.
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) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |