Patent US3972938A successfully refreshed from Google Patents.
US3972938A
Expired / Lapsed
US
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Manufacture of hexamethylene diamine
Assignee: BASF SE
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Filing: 1974-03-11
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Granted: 1976-08-03
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Expires: 1994-03-11
Abstract
Abstract A process for the catalytic hydrogenation of adiponitrile in the presence of ammonia, in which a portion of the reaction mixture is recycled and specific molar ratios of adiponitrile and ammonia are maintained.
Inventors
- 👤 Dieter Voges
- 👤 Leopold Hupfer
- 👤 Siegfried Winderl
- 👤 Karl Wilhelm Leonhard
- 👤 Herwig Hoffmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:19
CPC Classifications
C; C07; C07C; C07C209/00; C07C209/44; C07C209/48
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
122 words
A process for the continuous manufacture of 1,6-hexamethylene diamine which comprises continuously hydrogenating adiponitrile in the presence of ammonia in liquid phase and hydrogen and in the presence of hydrogenation catalysts at a hydrogen partial pressure of from 20 to 300 atmospheres gage and a temperature of from 40° to 130° C, in a reaction zone, and continuously withdrawing and recycling the major portion of the hydrogenated reaction mixture leaving the reaction zone, wherein adiponitrile and ammonia are added to the recycled hydrogenated reaction mixture in a molar ratio of from 1:10 to 1:15, the amount of hydrogenated reaction mixture recycled being such that the overall molar ratio of adiponitrile to ammonia on entering the reaction zone is from 1:40 to 1:55.
Claim 2
Dependent Claim
122 words
A process for the continuous manufacture of 1,6-hexamethylene diamine which comprises continuously hydrogenating adiponitrile in the presence of ammonia in liquid phase and hydrogen and in the presence of hydrogenation catalysts at a hydrogen partial pressure of from 20 to 300 atmospheres gage and a temperature of from 40° to 130° C, in a reaction zone, and continuously withdrawing and recycling the major portion of the hydrogenated reaction mixture leaving the reaction zone, wherein adiponitrile and ammonia are added to the recycled hydrogenated reaction mixture in a molar ratio of from 1:10 to 1:15, the amount of hydrogenated reaction mixture recycled being such that the overall molar ratio of adiponitrile to ammonia on entering the reaction zone is from 1:40 to 1:55.
Claim 3
Dependent Claim
24 words
A process as claimed in claim 1, wherein the molar ratio of adiponitrile to ammonia in the fresh feed is from 1:11 to 1:13.
Claim 4
Dependent Claim
25 words
A process as claimed in claim 1, wherein the molar ratio of adiponitrile to ammonia on entering the reaction zone is from 1:40 to 1:50.
Claim 5
Dependent Claim
21 words
A process as claimed in claim 1, wherein the reaction is carried out at temperatures of from 50° to 100° C.
Claim 6
Dependent Claim
25 words
A process as claimed in claim 1, wherein the reaction is carried out at a hydrogen partial pressure of from 30 to 260 atmospheres gage.
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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) | 1979-08-03 | 1980-02-02 | 1980-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-03 | 1984-02-02 | 1984-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-03 | 1988-02-02 | 1988-08-03 | $7700.00 | Window Closed / Lapsed |