US4746501A
Expired / Lapsed
US
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Process for preparing transition metal nitrides and transition metal carbonitrides and their reaction intermediates
Assignee: United States Department of Energy
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Filing: 1987-08-06
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Granted: 1988-05-24
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Expires: 2007-08-06
Abstract
Abstract A process for making ammonolytic precursors to nitride and carbonitride ceramics. Extreme reaction conditions are not required and the precursor is a powder-like substance that produces ceramics of improved purity and morphology upon pyrolysis.
Inventors
- 👤 Leon Maya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:22
CPC Classifications
C; C07; C07F; C07F9/00; C01; C01B; C01B21/00; C01B21/06; C01B21/0615; C01B21/0617; C01B21/062; C01B21/076; C01B21/0763; C01B21/082; C01B21/0828; C01B21/087; C01B21/092; C01B21/0923; C01P; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
89 words
A process for making a precursor to ceramics comprising: placing a transition metal halide and an alkali metal borohydride in liquid ammonia solvent resulting in the formation of an insoluble transition metal haloamide and soluble by-products, alkali metal halide and ammonium borohydride; separating said insoluble transition metal haloamide from said solvent and said soluble by-products; reacting said transition metal haloamide with a salt in liquid ammonia, said salt being one that will react by displacing the halogen atom of said transition metal haloamide and yield a precursor to ceramics.
Claim 2
Dependent Claim
89 words
A process for making a precursor to ceramics comprising: placing a transition metal halide and an alkali metal borohydride in liquid ammonia solvent resulting in the formation of an insoluble transition metal haloamide and soluble by-products, alkali metal halide and ammonium borohydride; separating said insoluble transition metal haloamide from said solvent and said soluble by-products; reacting said transition metal haloamide with a salt in liquid ammonia, said salt being one that will react by displacing the halogen atom of said transition metal haloamide and yield a precursor to ceramics.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein said salt is a carbon salt and said precursor is an organometallic amide.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein said salt is an amide salt and said precursor is a transition metal amide.
Claim 5
Dependent Claim
45 words
The process of claim 1 wherein said transition metal is selected from the group vanadium, tungsten, molybdenum, titanium, niobium; said halide is selected from the group chloride, bromide, and iodide; and said alkali metal borohydride is selected from the group potassium borohydride and sodium borohydride.
Claim 6
Dependent Claim
19 words
The process of claim 4 wherein said salt is a carbon salt and said precursor is an organometallic amide.
Claim 7
Dependent Claim
20 words
The process of claim 4 wherein said salt is an amine salt and said precursor is a transition metal amine.
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) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |