US5002646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making titanium nitride
Assignee: Tioxide Group Ltd
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Filing: 1989-04-20
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Granted: 1991-03-26
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Expires: 2009-04-20
Abstract
Abstract A method which comprises the manufacture of black titanium nitride which comprises heating ammonia and titanium halide by means of an electric plasma formed in a stream of non-oxidizing gas generated by the discharge of direct current electricty between a pair of electrodes. The heated gases are introduced through an inlet nozzle into a reactor so constructed and operated as to induce circulation of the gases with a specifically defined recirculation ratio.
Inventors
- 👤 Terence A. Egerton
- 👤 Anthony G. Jones
- 👤 Stephen R. Blackburn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:39
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/082; C01B21/0821; C01B21/06; C01B21/076; C01B21/0763; B; B01; B01J; B01J2219/00; B01J2219/08; B01J2219/0894; C01P; C01P2006/00; C01P2006/12; C01P2006/60; C01P2006/80
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
170 words
A method for the manufacture of black titanium nitride which comprises (a) heating ammonia and a halide of titanium to a chosen reaction temperature by means of an electric plasma formed in a stream of non-oxidising gas generated by the discharge of direct current electricity between a pair of electrodes, (b) introducing said heated gas through an inlet nozzle into a reactor and said reactor being so constructed and operated so as to induce circulation of the gaseous material in said reactor such that the recirculation ratio (RR) is greater than 2.5 and (c) collecting a black titanium nitride powder in which method the recirculation ratio is defined according to the formula: ##EQU2## wherein Mn=mass flow of gas stream through inlet nozzle R=internal radius of the reactor into which said nozzle flows M=mass flow at a distance 4R downstream from the inlet nozzle Rn=radius of inlet nozzle Dn=density of gas stream passing through the inlet nozzle D=density of gases in reactor at a distance 4R downstream from the inlet nozzle.
Claim 2
Independent Claim
170 words
A method for the manufacture of black titanium nitride which comprises (a) heating ammonia and a halide of titanium to a chosen reaction temperature by means of an electric plasma formed in a stream of non-oxidising gas generated by the discharge of direct current electricity between a pair of electrodes, (b) introducing said heated gas through an inlet nozzle into a reactor and said reactor being so constructed and operated so as to induce circulation of the gaseous material in said reactor such that the recirculation ratio (RR) is greater than 2.5 and (c) collecting a black titanium nitride powder in which method the recirculation ratio is defined according to the formula: ##EQU2## wherein Mn=mass flow of gas stream through inlet nozzle R=internal radius of the reactor into which said nozzle flows M=mass flow at a distance 4R downstream from the inlet nozzle Rn=radius of inlet nozzle Dn=density of gas stream passing through the inlet nozzle D=density of gases in reactor at a distance 4R downstream from the inlet nozzle.
Claim 3
Dependent Claim
36 words
A process according to claim 1 in which the concentration of the said titanium halide, without considering reaction or dissociation lies in the range 5 to 30 molar % with respect to the total gas system.
Claim 4
Dependent Claim
22 words
A process according to claim 1 in which the concentration of the said titanium halide lies in the range 7 to 25%.
Claim 5
Dependent Claim
15 words
A process according to claim 1 in which the said titanium halide is titanium tetrachloride.
Claim 6
Dependent Claim
28 words
A process according to claim 1 in which the net power provided in the plasma is from 50 to 500 kcals per minute per mole of titanium halide.
Claim 7
Dependent Claim
37 words
A process according to claim 1 in which the said non-oxidising gas is argon and said plasma is generated by a d.c. voltage of from 25 to 50 volts and a current of 200 to 600 amperes.
Claim 8
Dependent Claim
40 words
A process according to claim 1 in which the said non-oxidising gas is nitrogen or hydrogen and said plasma is generated by a d.c. voltage of from 90 to 250 volts and a current of from 80 to 250 amps.
Claim 9
Dependent Claim
18 words
A process according to claim 1 in which the said d.c. voltage is from 90 to 220 volts.
Claim 10
Dependent Claim
23 words
A process according to claim 1 in which the mass flow rate of titanium halide is from 0.1 to 5.0 mole per minute.
Claim 11
Dependent Claim
22 words
A process according to claim 1 in which the mass flow rate of ammonia is from 0.2 to 50.0 mole per minute.
Claim 12
Dependent Claim
15 words
A process according to claim 1 wherein the recirculation ratio is not greater than 10.
Claim 13
Dependent Claim
16 words
A process according to claim 1 wherein the recirculation ratio is from 3 to 9 inclusive.
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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) | 1994-03-25 | 1994-09-24 | 1995-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-25 | 1998-09-24 | 1999-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-25 | 2002-09-24 | 2003-03-26 | $7700.00 | Window Closed / Lapsed |