US2968676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of dpa over fluoride impregnated catalyst
Assignee: Wyeth Holdings LLC
•
Filing: 1958-10-06
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Granted: 1961-01-17
•
Expires: 1978-10-06
Abstract
No abstract record available.
Inventors
- 👤 Jr Allen G Potter
- 👤 Robert G Weyker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:40
CPC Classifications
C; C07; C07C; C07C209/00; C07C209/64
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
IN A PROCESS FOR THE MANUFACTURE OF DIPHENYLAMINE FROM ANILINE WHEREIN ANILINE VAPOR UNDR SUPERATMOSPHERIC PRESSURE IS CONTACTED WITH AN ALUMINA CATALYST AT A TEMPERATURE ABOVE 400*C., WHEREBY AN EFFLUENT VAPOR MIXTURE, CONTAINING PRODUCT DIPHENYLAMINE IS OBTAINED, THE IMPROVEMENT WHICH COMPRISES USING AS SAID CATALYST AN ACTIVATED ALUMINA PREPARED BY A PROCESS WHICH COMPRISES CONTACTING SAID ALUMINA IN PARTICULATE FORM WITH AN AQUEOUS SOLUTION CONTAINING A CONCENTRATION OF FROM ABOUT 0.5 TO ABOUT 10 WEIGHT PERCENT OF A WATER SOLUBLE INORGANIC FLUORIDE, SEPARATING SO-TREATED PARTICULATE ALUMINA FROM RESIDUAL AQUEOUS SOLUTION AND DRYING THE SOSEPARATED IMPREGNATED PARTICLES, SAID FLUORIDE BEING SELECTED FROM THE GROUP CONSISTING OF THE ALKALI METAL, AMMONIUM AND HYDROGEN FLUORIDES.
Claim 2
Dependent Claim
112 words
IN A PROCESS FOR THE MANUFACTURE OF DIPHENYLAMINE FROM ANILINE WHEREIN ANILINE VAPOR UNDR SUPERATMOSPHERIC PRESSURE IS CONTACTED WITH AN ALUMINA CATALYST AT A TEMPERATURE ABOVE 400*C., WHEREBY AN EFFLUENT VAPOR MIXTURE, CONTAINING PRODUCT DIPHENYLAMINE IS OBTAINED, THE IMPROVEMENT WHICH COMPRISES USING AS SAID CATALYST AN ACTIVATED ALUMINA PREPARED BY A PROCESS WHICH COMPRISES CONTACTING SAID ALUMINA IN PARTICULATE FORM WITH AN AQUEOUS SOLUTION CONTAINING A CONCENTRATION OF FROM ABOUT 0.5 TO ABOUT 10 WEIGHT PERCENT OF A WATER SOLUBLE INORGANIC FLUORIDE, SEPARATING SO-TREATED PARTICULATE ALUMINA FROM RESIDUAL AQUEOUS SOLUTION AND DRYING THE SOSEPARATED IMPREGNATED PARTICLES, SAID FLUORIDE BEING SELECTED FROM THE GROUP CONSISTING OF THE ALKALI METAL, AMMONIUM AND HYDROGEN FLUORIDES.
References Cited (Backward Citations)
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US1392942A
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US2098039A
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US2689226A
Cited
US2625570A
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-01-17 | 1964-07-18 | 1965-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-01-17 | 1968-07-18 | 1969-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-01-17 | 1972-07-18 | 1973-01-17 | $7700.00 | Window Closed / Lapsed |