US5164263A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aluminum nitride flakes and spheres
Assignee: EIDP Inc
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Filing: 1989-12-21
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Granted: 1992-11-17
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Expires: 2009-12-21
Abstract
Abstract Methods are described for preparing aluminum nitride of controllable morphology for ceramic and heat conduction applications. The methods comprise forming spherical particles or flakes of an intermediate, RAlNH, followed by heating the spheres or flakes of RAlNH at elevated temperatures to produce high purity aluminum nitride of corresponding morphology. Spheres of RAlNH are formed by (i) freezing a suspension of RAlNH in a liquid medium and thawing, by (ii) aging the suspension, or by (iii) dissolving RAlNH in a liquid medium and precipitating it. Flakes are formed by freezing a suspension of RAlNH in a liquid medium and removing frozen medium from the frozen suspension.
Inventors
- 👤 John D. Bolt
- 👤 Walter Mahler
- 👤 Frederick N. Tebbe
- 👤 Robert J. Young, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:09
CPC Classifications
B; B82; B82Y; B82Y30/00; C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/581; C01; C01B; C01B21/00; C01B21/06; C01B21/072; C01P; C01P2004/00; C01P2004/20; C01P2004/30; C01P2004/32; C01P2004/60; C01P2004/61; C01P2004/62; C01P2004/64; C01P2006/00; C01P2006/60; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/29; Y10T428/2982
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
48 words
A method for making spherical particles of RAlNH comprising dissolving RAlNH in a liquid medium and precipitating it by removing part of the liquid medium, wherein R is selected from at least one member of the group C x H 2x+1 , where x is 1 to 20.
Claim 2
Independent Claim
48 words
A method for making spherical particles of RAlNH comprising dissolving RAlNH in a liquid medium and precipitating it by removing part of the liquid medium, wherein R is selected from at least one member of the group C x H 2x+1 , where x is 1 to 20.
Claim 3
Independent Claim
71 words
A method for making spherical particles of aluminum nitride comprising heating the particles of RAlNH made by the method comprising dissolving RAlNH in a liquid medium and precipitating it by removing part of the liquid medium, wherein R is selected from at least one member of the group C x H 2x+1 , where x is 1 to 20, in the presence of a nitrogen-containing compound selected from ammonia and hydrazine.
Claim 4
Independent Claim
71 words
A method for making spherical particles of aluminum nitride comprising heating the particles of RAlNH made by the method comprising dissolving RAlNH in a liquid medium and precipitating it by removing part of the liquid medium, wherein R is selected from at least one member of the group C x H 2x+1 , where x is 1 to 20, in the presence of a nitrogen-containing compound selected from ammonia and hydrazine.
Claim 5
Independent Claim
35 words
A method for making spherical particles of aluminum nitride comprising heating the particles of RAlNH made by the method comprising dissolving RAlNH in a liquid medium and precipitating it by removing part of the liquid
Claim 6
Independent Claim
35 words
A method for making spherical particles of aluminum nitride comprising heating the particles of RAlNH made by the method comprising dissolving RAlNH in a liquid medium and precipitating it by removing part of the liquid
Claim 7
Dependent Claim
9 words
Flakes of aluminum nitride of approximately 1 μm thickness.
Claim 8
Dependent Claim
9 words
Flakes of aluminum nitride of approximately 1 μm thickness.
Claim 9
Dependent Claim
12 words
Flakes according to claim 4 of substantially theoretical density of aluminum nitride.
Claim 10
Dependent Claim
9 words
A densified material comprising the flakes of claim 4.
Claim 11
Dependent Claim
11 words
A densified material made by compacting the flakes of claim 4.
Claim 12
Dependent Claim
9 words
An electronic device comprising the flakes of claim 4.
Claim 13
Dependent Claim
11 words
An electronic device comprising flakes of claim 4 in compacted form.
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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) | 1995-11-17 | 1996-05-18 | 1996-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-17 | 2000-05-18 | 2000-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-17 | 2004-05-18 | 2004-11-17 | $7700.00 | Window Closed / Lapsed |