US2748172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of hydroquinone
Assignee: Eastman Kodak Co
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Filing: 1952-09-18
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Granted: 1956-05-29
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Expires: 1972-09-18
Abstract
No abstract record available.
Inventors
- 👤 George F Rodgers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:10
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
92 words
A PROCESS OF PREPARING HYDROQUINONE COMPRISING ADDING AN ACETONE SOLUTION OF P-DI-ISOPROPYL BENZENE DIHYDROPEROXIDE SLOWLY TO AN AQUEOUS SOLUTION OF PHOSPHORIC ACID OF ABOUT 10-85% CONCENTRATION AND AT A TEMPERATURE OF ABOUT 40-75* C., THE ADDITION BEING CARRIED OUT ONLY AS FAST AS THE DIHYDROPEROXIDE DECOMPOSES, AGITATING THE REACTION MIXTURE FOR A SHORT PERIOD OF TIME AFTER THE REACTION IS COMPLETE, ADDING ADDITIONAL WATER TO THE REACTION MIXTURE, RAISING THE TEMPERATURE OF THE MIXTURE TO ABOUT 95* C. TO DISTILL OFF ACETONE, EXTRACTING THE RESIDUE FROM THE DISTILLATION WITH BENZENE, AND SEPARATING
Claim 2
Dependent Claim
92 words
A PROCESS OF PREPARING HYDROQUINONE COMPRISING ADDING AN ACETONE SOLUTION OF P-DI-ISOPROPYL BENZENE DIHYDROPEROXIDE SLOWLY TO AN AQUEOUS SOLUTION OF PHOSPHORIC ACID OF ABOUT 10-85% CONCENTRATION AND AT A TEMPERATURE OF ABOUT 40-75* C., THE ADDITION BEING CARRIED OUT ONLY AS FAST AS THE DIHYDROPEROXIDE DECOMPOSES, AGITATING THE REACTION MIXTURE FOR A SHORT PERIOD OF TIME AFTER THE REACTION IS COMPLETE, ADDING ADDITIONAL WATER TO THE REACTION MIXTURE, RAISING THE TEMPERATURE OF THE MIXTURE TO ABOUT 95* C. TO DISTILL OFF ACETONE, EXTRACTING THE RESIDUE FROM THE DISTILLATION WITH BENZENE, AND SEPARATING
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-05-29 | 1959-11-28 | 1960-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-05-29 | 1963-11-28 | 1964-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-05-29 | 1967-11-28 | 1968-05-29 | $7700.00 | Window Closed / Lapsed |