US5429647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making abrasive grain containing alumina and ceria
Assignee: 3M Co
•
Filing: 1994-01-13
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Granted: 1995-07-04
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Expires: 2014-01-13
Abstract
Abstract A method of preparing abrasive grain includes: preparing a dispersion including alpha alumina oxide monohydrate and ceria sol therein; converting the dispersion to base grit material; and sintering the base grit to form abrasive grains. The grain are useful in abrasive products.
Inventors
- 👤 Henry A. Larmie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:02
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/14; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/1115; C04B35/622; C04B35/626; C09K3/1409; C09K3/1418
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
138 words
A method of preparing abrasive grain, said method comprising the steps of: (a) preparing a dispersion comprising alumina hydrate and a sufficient amount of a sol of ceria particles to provide after steps (b) and (c) abrasive grain having greater than 0.5% by weight ceria present as one of ceria, at least one ceria reaction product, or a combination thereof, based on the total weight of said abrasive grain, wherein at least about 97% by weight of said ceria particles are less than about 0.5 micrometer in size; (b) forming alumina base grits from said dispersion; and (c) sintering said alumina base grits to provide abrasive grain comprising greater than 0.5% by weight ceria present as one of ceria, at least one ceria reaction product, or a combination thereof, based on the total weight of said abrasive grain.
Claim 2
Independent Claim
138 words
A method of preparing abrasive grain, said method comprising the steps of: (a) preparing a dispersion comprising alumina hydrate and a sufficient amount of a sol of ceria particles to provide after steps (b) and (c) abrasive grain having greater than 0.5% by weight ceria present as one of ceria, at least one ceria reaction product, or a combination thereof, based on the total weight of said abrasive grain, wherein at least about 97% by weight of said ceria particles are less than about 0.5 micrometer in size; (b) forming alumina base grits from said dispersion; and (c) sintering said alumina base grits to provide abrasive grain comprising greater than 0.5% by weight ceria present as one of ceria, at least one ceria reaction product, or a combination thereof, based on the total weight of said abrasive grain.
Claim 3
Dependent Claim
51 words
A method according to claim 1 wherein said dispersion comprises a sufficient amount of a sol of ceria particles to provide after steps (b) and (c) abrasive grain having at least about 1% by weight ceria present as one of ceria, at least one ceria reaction product, or a combination thereof.
Claim 4
Dependent Claim
28 words
A method according to claim 2 wherein said dispersion is aqueous, and wherein said alumina base grits of step (b) are calcined before said sintering of step (c).
Claim 5
Dependent Claim
69 words
A method according to claim 1 wherein said dispersion is aqueous and contains sufficient ceria therein such that said abrasive grain comprises between greater than 0.5 and about 15% by weight ceria present as one of ceria, at least one ceria reaction product, or a combination thereof, and said method further comprises the step of calcining said alumina base grits of step (b) before said sintering of step (c).
Claim 6
Dependent Claim
31 words
A method according to claim 3 wherein said ceria sol of step (a) comprises less than about 50% by weight colloidal ceria particles of less than about 0.1 micrometer in size.
Claim 7
Dependent Claim
13 words
A method according to claim 3 wherein said dispersion further comprises zirconia sol.
Claim 8
Dependent Claim
15 words
A method according to claim 3 wherein said aqueous dispersion further comprises a nucleating material.
Claim 9
Dependent Claim
23 words
A method according to claim 3 including providing said sintered abrasive grain with a coating comprising zirconia, alumina, silica, or a combination thereof.
Claim 10
Dependent Claim
63 words
A method according to claim 3, wherein said calcined alumina base grits are porous, said method further comprising the steps of: (i) impregnating said porous alumina base grit material with an impregnating solution of precursor of an oxide selected from the group consisting of: lanthanum, neodymium, yttrium, magnesium, zirconium, and mixtures thereof; and (ii) calcining the impregnated grit prior to said sintering step.
Claim 11
Dependent Claim
116 words
A method according to claim 9, wherein said alumina hydrate is present in said dispersion in an amount sufficient to provide said abrasive grain with about 70 to less than 99.5% by weight alumina; and said sol of ceria particles is present in said dispersion in an amount sufficient to provide said abrasive grain with greater than 0.5 to about 15% by weight ceria; and a sufficient amount of said oxide precursor being impregnated into said alumina base grit to provide up to about 15% by weight of metal oxide selected from the group consisting of magnesium oxide, zirconia, lanthanum oxide, neodymium oxide, yttria, and combinations thereof, based on the total weight of said abrasive grain.
Claim 12
Independent Claim
75 words
A method of preparing abrasive grain, said method comprising the steps of: (a) preparing a dispersion comprising alumina hydrate and an effective amount of a sol of ceria particles, wherein at least about 97% by weight of said ceria particles are less than about 0.5 micrometer in size, said dispersion being essentially free of cerium salt; (b) forming alumina base grits from said dispersion; and (c) sintering said alumina base grits to provide abrasive grain.
Claim 13
Independent Claim
75 words
A method of preparing abrasive grain, said method comprising the steps of: (a) preparing a dispersion comprising alumina hydrate and an effective amount of a sol of ceria particles, wherein at least about 97% by weight of said ceria particles are less than about 0.5 micrometer in size, said dispersion being essentially free of cerium salt; (b) forming alumina base grits from said dispersion; and (c) sintering said alumina base grits to provide abrasive grain.
Claim 14
Dependent Claim
28 words
A method according to claim 11 wherein said dispersion is aqueous, and wherein said alumina base grits of step (b) are calcined before said sintering of step (c).
Claim 15
Dependent Claim
28 words
A method according to claim 12 wherein said dispersion contains sufficient ceria therein such that said abrasive grain comprises between about 0.1 and about 15% by weight ceria.
Claim 16
Dependent Claim
31 words
A method according to claim 12 wherein said ceria sol of step (a) comprises less than about 50% by weight colloidal ceria particles of less than about 0.1 micrometer in size.
Claim 17
Dependent Claim
13 words
A method according to claim 12 wherein said dispersion further comprises zirconia sol.
Claim 18
Dependent Claim
15 words
A method according to claim 12 wherein said aqueous dispersion further comprises a nucleating material.
Claim 19
Dependent Claim
31 words
A method according to claim 12 wherein said aqueous dispersion further comprises a precursor of an oxide selected from the group consisting of: lanthanum, neodymium, yttrium, magnesium, zirconium, and mixtures thereof.
Claim 20
Dependent Claim
42 words
A method according to claim 12 including a step of impregnating said calcined alumina base grits with a precursor of an oxide selected from the group consisting of: lanthanum, neodymium, yttrium, magnesium, zirconium, and mixtures thereof prior to said step of sintering.
Claim 21
Dependent Claim
23 words
A method according to claim 12 including providing said sintered abrasive grain with a coating comprising zirconia, alumina, silica, or a combination thereof.
Claim 22
Dependent Claim
65 words
A method according to claim 12, wherein said calcined alumina base grits are porous, said method further comprising the steps of: (i) impregnating said porous alumina base grit material with an impregnating solution of oxide precursor selected from the group consisting of precursor to oxides of: lanthanum, neodymium, yttrium, magnesium, zirconium, and mixtures thereof; and (ii) calcining the impregnated grit prior to said sintering step.
Claim 23
Dependent Claim
113 words
A method according to claim 20 wherein said alumina hydrate is present in said dispersion in an amount sufficient to provide said abrasive grain with about 70 to about 99.9% by weight alumina; said sol of ceria particles is present in said dispersion in an amount sufficient to provide said abrasive grain with about 0.1 to about 15% by weight ceria; and a sufficient amount of said oxide precursor is impregnated into said alumina base grit to provide up to about 15% by weight of metal oxide selected from the group consisting of magnesium oxide, zirconia, lanthanum oxide, neodymium oxide, yttria, and combinations thereof, based on the total weight of said abrasive grain.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-07-03 | 1999-01-02 | 1999-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-03 | 2003-01-02 | 2003-07-04 | $3760.00 | Window Closed / Lapsed |
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