US3920743A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of preparing aromatic amines
Assignee: Hoechst AG
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Filing: 1974-10-17
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Granted: 1975-11-18
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Expires: 1994-10-17
Abstract
Abstract Sulfided platinum on carbon catalysts being useful in the selective hydrogenation of halonitroaromates are obtained by saturating a particulate platinum on carbon catalyst with hydrogen in an acidic aqueous medium and treating it with defined amounts of a sulfidizing agent. Said catalysts maintain their activity and selectivity for numerous hydrogenations.
Inventors
- 👤 Konrad Baessler
- 👤 Kurt Mayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:17
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/20; B01J23/00; B01J23/38; B01J23/40; B01J23/42
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
109 words
IN A PROCESS FOR THE HYDROGENATION OF HALONITRO-AROMATES SELCTED FROM THE GROUP CONSISTING OF CHLORO-NITROBENZENE, DICHLORO-NITROBENZENE AND CHLORO NITRO MTHYLBENZENE, THE IMPROVEMENT CONSISTING ESSENTIALLY OF HYDROGENATING SAID COMPOUNDS IN THE PRESENCE OF A SULFIED PLATINUM ON CARBON CATALYST OBTAINED BY SUSPENDING A PARTICULAR PLATINUM ON CARBON CATALYST HAVING AN EFFECTIVE SURFACE OF AT LEAST 800 M2/G IN AN AQUEOUS MEDIUM OF A PH IN THE RANGE OF 0 TO 5, SATURATING WITH HYDROGEN AT A PRESSURE IN THE RANGE OFF NORMAL PRESSURE TO 1 ATMG. TREATING WITH 0.2 TO 0.7 MOL OF A SULFIDIZING AGENT PER EACH MOL OF HYDROGEN ABSORBED AND ISOLATING THE CATALYST FROM THE AQUEOUS MEDIUM.
Claim 2
Dependent Claim
109 words
IN A PROCESS FOR THE HYDROGENATION OF HALONITRO-AROMATES SELCTED FROM THE GROUP CONSISTING OF CHLORO-NITROBENZENE, DICHLORO-NITROBENZENE AND CHLORO NITRO MTHYLBENZENE, THE IMPROVEMENT CONSISTING ESSENTIALLY OF HYDROGENATING SAID COMPOUNDS IN THE PRESENCE OF A SULFIED PLATINUM ON CARBON CATALYST OBTAINED BY SUSPENDING A PARTICULAR PLATINUM ON CARBON CATALYST HAVING AN EFFECTIVE SURFACE OF AT LEAST 800 M2/G IN AN AQUEOUS MEDIUM OF A PH IN THE RANGE OF 0 TO 5, SATURATING WITH HYDROGEN AT A PRESSURE IN THE RANGE OFF NORMAL PRESSURE TO 1 ATMG. TREATING WITH 0.2 TO 0.7 MOL OF A SULFIDIZING AGENT PER EACH MOL OF HYDROGEN ABSORBED AND ISOLATING THE CATALYST FROM THE AQUEOUS MEDIUM.
References Cited (Backward Citations)
US3350450A
Cited
US3261869A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |