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US5078980A
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US
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Process for the removal of isocyanic acid from a mixture of isocyanic acid and ammonia
Assignee: Chemie Linz GmbH
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Filing: 1990-07-12
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Granted: 1992-01-07
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Expires: 2010-07-12
Abstract
Abstract Process for the removal of isocyanic acid from a gaseous mixture of isocyanic acid and ammonia by introducing a tertiary amine or ether at 250° to 600° C. The gaseous reaction mixture is passed into an inert diluent and cooled, to condense an adduct of isocyanic acid and tertiary amine or ether, and the ammonia being removed as a gas.
Inventors
- 👤 Martin Mullner
- 👤 Gerhard Stern
- 👤 Erich Schulz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:15
CPC Classifications
C; C07; C07C; C07C263/00; C07C263/18; C07C273/00; C07C273/18; C07C273/1809; C07C273/1818; C07C273/1827; C01; C01C; C01C3/00; C01C3/14; C01C3/145; C07C333/00; C07C333/02; C07C333/04
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
77 words
A process for the removal of isocyanic acid from a gaseous mixture of isocyanic acid and ammonia comprising introducing a tertiary amine or an ether into a gaseous mixture of isocyanic acid and ammonia at a temperature of 250° to 600 ° C. and introducing the resulting gaseous reaction mixture into a diluent which is inert under the reaction conditions, and cooling the reaction mixture whereby an adduct of isocyanic acid and tertiary amine or ether condenses.
Claim 2
Dependent Claim
77 words
A process for the removal of isocyanic acid from a gaseous mixture of isocyanic acid and ammonia comprising introducing a tertiary amine or an ether into a gaseous mixture of isocyanic acid and ammonia at a temperature of 250° to 600 ° C. and introducing the resulting gaseous reaction mixture into a diluent which is inert under the reaction conditions, and cooling the reaction mixture whereby an adduct of isocyanic acid and tertiary amine or ether condenses.
Claim 3
Dependent Claim
51 words
A process according to claim 1, comprising employing a tertiary cyclic amine or an amine of the general formula NR 1 R 2 R 3 in which the radicals R 1 , R 2 and R 3 independently of one another denote straight-chain or branched alkyl, aryl, alkylaryl or arylalkyl groups.
Claim 4
Dependent Claim
10 words
A process according to claim 2, comprising employing a trialkylamine.
Claim 5
Dependent Claim
72 words
A process according to claim 1, comprising employing a cyclic ether or an ether of the general formula R 1 --O--(R 4 --O) n --R 2 in which the radicals R 1 and R 2 independently of one another denote a straight-chain or branched alkyl, aryl, alkylaryl or arylalkyl group, R 4 denotes a straight-chain or branched alkylene, arylene, alkylarylene or arylalkylene group and n denotes an integer from 0 to 5.
Claim 6
Dependent Claim
60 words
A process according to claim 4, comprising employing an ether of the formula R 1 --O--R 2 in which R 1 and R 2 are identical and denote alkyl groups, or an ether of the formula R 1 --O--R 4 --O--R 2 in which R 1 and R 2 have the abovementioned meaning and R 4 denotes an alkylene group.
Claim 7
Dependent Claim
26 words
A process according to one of claims 1 to 4, comprising introducing 1 to 7 moles of tertiary amine or ether per mole of isocyanic acid.
Claim 8
Dependent Claim
30 words
A process according to one of claims 1 to 5, comprising carrying out the addition of the tertiary amine or the ether at a temperature of 320° to 380° C.
Claim 9
Dependent Claim
33 words
A process according to one of claims 1 to 4, comprising employing an optionally halogenated aliphatic or aromatic hydrocarbon, an ether, a carboxamide or a mixture of the abovementioned diluents as the diluent.
Claim 10
Dependent Claim
27 words
A process according to one of claims 4 or 5, comprising employing the ether which also forms the adduct of isocyanic acid and ether as the diluent.
References Cited (Backward Citations)
US1887608A
Cited
DE1204643B
Cited
US3752880A
Cited
GB1373291A
Cited
US4398036A
Cited
EP0124704A2
Cited
EP0255022A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-06 | 1995-07-08 | 1996-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-06 | 1999-07-08 | 2000-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-06 | 2003-07-08 | 2004-01-07 | $7700.00 | Window Closed / Lapsed |