Patent US4758539A successfully refreshed from Google Patents.
US4758539A
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Process for producing ceramic nitrides and carbonitrides and their precursors
Assignee: United States Department of Energy
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Filing: 1987-02-25
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Granted: 1988-07-19
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Expires: 2007-02-25
Abstract
Abstract A process for preparing ceramic nitrides and carbonitrides in the form of very pure, fine particulate powder. Appropriate precursor is prepared by reacting a transition metal alkylamide with ammonia to produce a mixture of metal amide and metal imide in the form of an easily pyrolyzable precipitate.
Inventors
- 👤 Gilbert M. Brown
- 👤 Leon Maya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:45
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/58007; C04B35/58014; C04B35/58021; C01; C01B; C01B21/00; C01B21/06; C01B21/0615; C01B21/0617; C01B21/062; C01B21/076; C01B21/0766; C01B21/082; C01B21/0828; C04B35/58028; C04B35/58035; C01P; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
26 words
A process for preparing a ceramic precursor comprising the steps: (A) reacting a transition metal alkylamide with ammonia to produce a precipitate; (B) isolating said precipitate.
Claim 2
Dependent Claim
26 words
A process for preparing a ceramic precursor comprising the steps: (A) reacting a transition metal alkylamide with ammonia to produce a precipitate; (B) isolating said precipitate.
Claim 3
Dependent Claim
10 words
A ceramic precursor prepared by the process of claim 1.
Claim 4
Dependent Claim
32 words
The process of claim 1 wherein said transition metal alkylamide is an alkylamide of a transition metal selected from the group consisting of titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten.
Claim 5
Dependent Claim
10 words
A ceramic precursor prepared by the process of claim 3.
Claim 6
Dependent Claim
20 words
The process of claim 3 wherein said transition metal is selected from the group consisting of titanium, zirconium and niobium.
Claim 7
Dependent Claim
10 words
A ceramic precursor prepared by the process of claim 5.
Claim 8
Dependent Claim
27 words
A process for preparing ceramics comprising reacting a transition metal alkylamide with ammonia to produce a precipitate; isolating said precipitate; pyrolyzing said precipitate in a nonoxidizing environment.
Claim 9
Dependent Claim
27 words
A process for preparing ceramics comprising reacting a transition metal alkylamide with ammonia to produce a precipitate; isolating said precipitate; pyrolyzing said precipitate in a nonoxidizing environment.
Claim 10
Dependent Claim
10 words
The process of claim 7 wherein said atmosphere is hydrogen.
Claim 11
Dependent Claim
32 words
The process of claim 7 wherein said transition metal alkylamide is an alkylamide of a transition metal selected from the group consisting of titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum and tungsten.
Claim 12
Dependent Claim
10 words
The process of claim 9 wherein said atmosphere is hydrogen.
Claim 13
Dependent Claim
21 words
The process of claim 9 wherein said transition metal alkylamide is selected from the group consisting of titanium, zirconium and niobium.
Claim 14
Dependent Claim
10 words
The process of claim 11 wherein said atmosphere is hydrogen.
Claim 15
Dependent Claim
19 words
The process of claim 7 wherein said precipitate is pyrolyzed at a temperature of about 600° C. or greater.
Claim 16
Dependent Claim
19 words
The process of claim 9 wherein said precipitate is pyrolyzed at a temperature of about 600° C. or greater.
Claim 17
Dependent Claim
19 words
The process of claim 11 wherein said precipitate is pyrolyzed at a temperature of about 600° C. or greater.
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) | 1991-07-19 | 1992-01-18 | 1992-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-19 | 1996-01-18 | 1996-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-19 | 2000-01-18 | 2000-07-19 | $7700.00 | Window Closed / Lapsed |