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Patent US5155071A successfully refreshed from Google Patents.
US5155071A
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US
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Flame-produced partially stabilized zirconia powder
Assignee: Alfred University
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Filing: 1991-08-16
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Granted: 1992-10-13
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Expires: 2011-08-16
Abstract
Abstract Partially stabilized cubic or tetragonal zirconia powder are provided which comprise aggregates of dense equiaxial primary particles, wherein said particles have an average diameter of less than about 150 nm and comprise zirconia and a homogeneously distributed stabilizer, as well as processes for their production employing flame combustion of homogeneous mixtures of ZrCl4 and stabilizer precursors.
Inventors
- 👤 Howard W. Jacobson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:50
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/486; C01; C01G; C01G25/00; C01G25/02; C04B35/622; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3231; C04B2235/3244; C04B2235/3246; Y; Y10; Y10S; Y10S977/00; Y10S977/70; Y10S977/773; Y10S977/775; Y10S977/776
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
33 words
A partially stabilized zirconia powder, comprising aggregates of dense equiaxial primary particles, wherein said particles have an average diameter of less than about 150 nm and comprise zirconia and a homogeneously distributed stabilizer.
Claim 2
Dependent Claim
33 words
A partially stabilized zirconia powder, comprising aggregates of dense equiaxial primary particles, wherein said particles have an average diameter of less than about 150 nm and comprise zirconia and a homogeneously distributed stabilizer.
Claim 3
Dependent Claim
19 words
A zirconia powder of claim 1, wherein the particles have an average diameter of less than about 50 nm.
Claim 4
Dependent Claim
12 words
A zirconia powder of claim 1, wherein the zirconia is primarily cubic.
Claim 5
Dependent Claim
22 words
A zirconia powder of claim 3, wherein the concentration of stabilizer is about 7 to 15 wt % of the total powder.
Claim 6
Dependent Claim
12 words
A zirconia powder of claim 1, wherein the zirconia is primarily tetragonal.
Claim 7
Dependent Claim
22 words
A zirconia powder of claim 5, wherein the concentration of stabilizer is about 1 to 7 wt % of the total powder.
Claim 8
Dependent Claim
27 words
A zirconia powder of claim 1, wherein the stabilizer precursor powder is a halide, nitrate or acetate of magnesium, calcium, cerium, or yttrium or a mixture thereof.
Claim 9
Independent Claim
58 words
A method of preparing a partially stabilized zirconia powder, said powder comprising aggregates of dense equiaxial primary particles, wherein said particles have an average diameter of less than about 150 nm and comprise zirconia and homogeneously distributed stabilizer, comprising combusting a homogeneous mixture of (a) a combustible zirconia precursor and (b) a one or more combustible stabilizer precursors.
Claim 10
Independent Claim
58 words
A method of preparing a partially stabilized zirconia powder, said powder comprising aggregates of dense equiaxial primary particles, wherein said particles have an average diameter of less than about 150 nm and comprise zirconia and homogeneously distributed stabilizer, comprising combusting a homogeneous mixture of (a) a combustible zirconia precursor and (b) a one or more combustible stabilizer precursors.
Claim 11
Dependent Claim
15 words
A method according to claim 8 wherein the combustion step occurs in a flame reactor.
Claim 12
Dependent Claim
19 words
A method according to claim 8, wherein (a) and (b) are fed to a vaporizer by a powder feeder.
Claim 13
Dependent Claim
22 words
A method according to claim 10, wherein at least one of (a) and (b) is vaporized in said vaporizer prior to combustion.
Claim 14
Dependent Claim
15 words
A method according to claim 11 wherein the combustion step occurs in a flame reactor.
Claim 15
Dependent Claim
19 words
A method according to claim 9 or claim 12, wherein the combustion products are quenched in a controlled fashion.
Claim 16
Dependent Claim
24 words
A method according to claim 8 or claim 9 or claim 12, wherein the combustion occurs at temperatures of about 1400° to 2500° C.
Claim 17
Independent Claim
122 words
A method of preparing a partially stabilized zirconia powder, said powder comprising aggregates of dense equiaxial primary particles, wherein said particles have an average diameter of less than about 150 nm and comprise zirconia and homogeneously distributed stabilizer, comprising a) intimately mixing ZrCl 4 powder with a stabilizer precursor powder or a combination of stabilizer precursor powders; b) powder feeding said powder mixture with an inert gas into a vaporizer at a controlled rate; c) vaporizing the volatile components of the powder mixture; d) combusting in a flame reactor the components from step c) conveyed to the flame reactor uniformly in an inert gas, a combustible hydrocarbon gas and oxygen; e) quenching the combustion reaction; and f) recovering partially stabilized zirconia powder.
Claim 18
Independent Claim
122 words
A method of preparing a partially stabilized zirconia powder, said powder comprising aggregates of dense equiaxial primary particles, wherein said particles have an average diameter of less than about 150 nm and comprise zirconia and homogeneously distributed stabilizer, comprising a) intimately mixing ZrCl 4 powder with a stabilizer precursor powder or a combination of stabilizer precursor powders; b) powder feeding said powder mixture with an inert gas into a vaporizer at a controlled rate; c) vaporizing the volatile components of the powder mixture; d) combusting in a flame reactor the components from step c) conveyed to the flame reactor uniformly in an inert gas, a combustible hydrocarbon gas and oxygen; e) quenching the combustion reaction; and f) recovering partially stabilized zirconia powder.
Claim 19
Dependent Claim
26 words
A method of claim 15, wherein the stabilizer precursor powder is a halide, nitrate or acetate of magnesium, calcium, cerium, or yttrium or a mixture thereof.
Claim 20
Dependent Claim
14 words
A method of claim 15, wherein the vaporization temperature is 350° to 600° C.
Claim 21
Dependent Claim
14 words
A method of claim 15, wherein the combustion temperature is 1400° to 2500° C.
Claim 22
Dependent Claim
14 words
A method of claim 15, wherein the combustion time is 10 to 200 msec.
Claim 23
Dependent Claim
14 words
A method of claim 15, wherein the quenching temperature is 1400° to 100° C.
Claim 24
Dependent Claim
30 words
A method of claim 15, further comprising a step of maintaining the combustion products immediately after combustion at a temperature of 1200° to 2000° C. for 10 to 500 msec.
Claim 25
Dependent Claim
47 words
A partially stabilized cubic or tetragonal zirconia powder, comprising aggregates of dense equiaxial primary particles, wherein said particles have an average diameter of less than about 150 nm and comprise zirconia and a homogeneously distributed stabilizer, produced by a method according to claim 8 or claim 15.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 7.5 Years (Year 8) | 1999-10-13 | 2000-04-13 | 2000-10-13 | $3760.00 | Window Closed / Lapsed |
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