Patent US4744802A successfully refreshed from Google Patents.
US4744802A
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US
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Process for durable sol-gel produced alumina-based ceramics, abrasive grain and abrasive products
Assignee: 3M Co
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Filing: 1987-01-07
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Granted: 1988-05-17
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Expires: 2007-01-07
Abstract
Abstract A sol-gel process of producing durable alpha alumina-based ceramic particularly useful as abrasive grain from alpha alumina monohydrate is improved by the addition of a nucleating agent. Improved abrasive products containing the durable ceramic abrasive grains are also provided.
Inventors
- 👤 Mark G. Schwabel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:47
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; B; B82; B82Y; B82Y30/00; C01; C01F; C01F7/00; C01F7/02; C01F7/34; C01F7/36; C01F7/44; C01F7/441; C01F7/442; C04B35/111; C04B35/1115; C04B35/16; C04B35/18; C09; C09C; C09C1/00; C09K; C09K3/00; C09K3/14; C09K3/1409; C09K3/1418; C01P; C01P2004/00; C01P2004/60; C01P2004/62; C01P2004/64; C01P2006/00; C01P2006/10; C01P2006/21
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
80 words
In the sol-gel process for forming alumina-based ceramic, the process comprising: a. preparing a dispersion of alpha alumina monohydrate particles; b. gelling the dispersion; c. drying the gel dispersion to form a solid; d. calcining the solid; and e. sintering the calcined solid, the improvement comprising introducing nucleating agents into the dispersion before the drying step by adding to the dispersion a nucleating agent selected from the group consisting of a precursor of alpha ferric oxide and alpha ferric oxide.
Claim 2
Dependent Claim
80 words
In the sol-gel process for forming alumina-based ceramic, the process comprising: a. preparing a dispersion of alpha alumina monohydrate particles; b. gelling the dispersion; c. drying the gel dispersion to form a solid; d. calcining the solid; and e. sintering the calcined solid, the improvement comprising introducing nucleating agents into the dispersion before the drying step by adding to the dispersion a nucleating agent selected from the group consisting of a precursor of alpha ferric oxide and alpha ferric oxide.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the gel also contains a percursor of a modifying additive.
Claim 4
Dependent Claim
13 words
The process of claim 2 where the modifying additive is a metal-containing compound.
Claim 5
Dependent Claim
27 words
The process of claim 3 where the metal-containing compound is at least one precursor of the oxides of magnesium, zinc, cobalt, nickel, zirconium, hafnium, chromium and titanium.
Claim 6
Dependent Claim
13 words
The process of claim 1 where the nucleating agent is alpha ferric oxide.
Claim 7
Dependent Claim
22 words
The process of claim 1 where the nucleating sites are introduced by adding to the dispersion a precursor of alpha ferric oxide.
Claim 8
Dependent Claim
26 words
The process of claim 6 where the amount by weight of alpha ferric oxide is less than the amount by weight of alpha alumina monohydrate particles.
Claim 9
Dependent Claim
13 words
The process of claim 1 where the alumina-based ceramic is an abrasive grain.
Claim 10
Dependent Claim
13 words
The process of claim 1 including the step of crushing the calcined solid.
Claim 11
Dependent Claim
14 words
Alumina-based sol-gel ceramic comprising alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 12
Dependent Claim
14 words
Alumina-based sol-gel ceramic comprising alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 13
Dependent Claim
11 words
The alumina-based sol-gel ceramic of claim 10 including a modifying additive.
Claim 14
Dependent Claim
17 words
The alumina-based sol-gel ceramic consisting essentially of alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 15
Dependent Claim
17 words
The alumina-based sol-gel ceramic consisting essentially of alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 16
Dependent Claim
17 words
Abrasive grain comprising alumina-based sol-gel ceramic comprising alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 17
Dependent Claim
17 words
Abrasive grain comprising alumina-based sol-gel ceramic comprising alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 18
Dependent Claim
10 words
The abrasive grain of claim 13 including a modifying additive.
Claim 19
Dependent Claim
19 words
The abrasive grain of claim 13 consisting essentially of alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 20
Dependent Claim
27 words
An abrasive article comprising abrasive grain at least a portion of which comprises sol-gel abrasive grain comprising alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 21
Dependent Claim
27 words
An abrasive article comprising abrasive grain at least a portion of which comprises sol-gel abrasive grain comprising alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 22
Dependent Claim
16 words
An abrasive article of claim 16 where said sol-gel abrasive grain also includes a modifying additive.
Claim 23
Dependent Claim
29 words
An abrasive article comprising abrasive grain at least a portion of which comprises sol-gel abrasive grain consisting essentially of alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 24
Dependent Claim
29 words
An abrasive article comprising abrasive grain at least a portion of which comprises sol-gel abrasive grain consisting essentially of alpha alumina having alpha ferric oxide nucleating material dispersed therein.
Claim 25
Dependent Claim
17 words
The abrasive article of claim 16, 17 or 18 in the form of a coated abrasive product.
Claim 26
Dependent Claim
17 words
The abrasive article of claim 16, 17 or 18 in the form of a bonded abrasive product.
Claim 27
Dependent Claim
15 words
The bonded abrasive article of claim 19 in the form of a bonded abrasive wheel.
Claim 28
Dependent Claim
18 words
The abrasive article of claims 16, 17 or 18 in the form of a lofty non-woven abrasive product.
Claim 29
Dependent Claim
32 words
Alumina-based sol-gel ceramic comprising alpha alumina substantially in the form of domains which contain a nucleating amount of alpha ferric oxide and have an average diameter of less than about 5 micrometers.
Claim 30
Dependent Claim
32 words
Alumina-based sol-gel ceramic comprising alpha alumina substantially in the form of domains which contain a nucleating amount of alpha ferric oxide and have an average diameter of less than about 5 micrometers.
Claim 31
Dependent Claim
20 words
The alumina-based sol-gel ceramic of claim 23 where said domains have an average diameter of less than about 2 micrometers.
Claim 32
Dependent Claim
12 words
The alumina-based sol-gel ceramic of claim 23 also including a modifying additive.
Claim 33
Dependent Claim
12 words
The alumina-based sol-gel ceramic of claim 23 consisting essentially of alpha alumina.
Claim 34
Dependent Claim
35 words
Abrasive grain comprising alumina-based sol-gel ceramic comprising alpha alumina substantially in the form of domains which contain a nucleating amount of alpha ferric oxide and have an average diameter of less than about 5 micrometers.
Claim 35
Dependent Claim
35 words
Abrasive grain comprising alumina-based sol-gel ceramic comprising alpha alumina substantially in the form of domains which contain a nucleating amount of alpha ferric oxide and have an average diameter of less than about 5 micrometers.
Claim 36
Dependent Claim
19 words
The abrasive grain of claim 27 where said domains have an average diameter of less than about 2 micrometers.
Claim 37
Dependent Claim
11 words
The abrasive grain of claim 27 also including a modifying additive.
Claim 38
Dependent Claim
15 words
The abrasive grain of claim 27 consisting essentially of alpha alumina and alpha ferric oxide.
Claim 39
Dependent Claim
27 words
An abrasive article including abrasive grain, at least a portion of which comprises the sol-gel abrasive grain of any one of claims 27, 28, 29 or 30.
Claim 40
Dependent Claim
28 words
An abrasive article including abrasive grain comprising the sol-gel abrasive grain of any one of claims 27, 28, 29 or 30 and any other type of abrasive grain.
Claim 41
Dependent Claim
22 words
A coated abrasive article including abrasive grain comprising the sol-gel abrasive grain of any one of claims 27, 28, 29 or 30.
Claim 42
Dependent Claim
29 words
A coated abrasive article including abrasive grain comprising the sol-gel abrasive grain of any one of claims 27, 28, 29 or 30 and any other type of abrasive grain.
Claim 43
Dependent Claim
21 words
A bonded abrasive product including abrasive grain comprising the abrasive grain of any one of claims 27, 28, 29 or 30.
Claim 44
Dependent Claim
28 words
A bonded abrasive product including abrasive grain comprising the abrasive grain of any one of claims 27, 28, 29 or 30 and any other type of abrasive grain.
Claim 45
Dependent Claim
23 words
A lofty nonwoven abrasive product including abrasive grain comprising the abrasive grain of any of one of claims 27, 28, 29 or 30.
Claim 46
Dependent Claim
14 words
The process of claim 1 including the step of shaping the gel before drying.
Claim 47
Dependent Claim
14 words
The process of claim 38 wherein said shaping is accomplished by extruding the gel.
Claim 48
Dependent Claim
12 words
The abrasive grain of claim 13 wherein said aluminabased ceramic is shaped.
Claim 49
Dependent Claim
19 words
An abrasive article comprising abrasive grain at least a portion of which is the abrasive grain of claim 40.
Claim 50
Dependent Claim
14 words
The abrasive article of claim 41 in the form of a coated abrasive product.
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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) | 1991-05-17 | 1991-11-16 | 1992-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-17 | 1995-11-16 | 1996-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-17 | 1999-11-16 | 2000-05-17 | $7700.00 | Window Closed / Lapsed |