Patent US3798277A successfully refreshed from Google Patents.
US3798277A
Expired / Lapsed
US
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Process for the preparation of hydroquinone
Assignee: Fujifilm Holdings Corp
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Filing: 1971-06-18
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Granted: 1974-03-19
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Expires: 1991-06-18
Abstract
Abstract A PROCESS FOR OBTAINING HYDROQINONE IS DISCLOSED WHEREIN THE DECOMPOSITION REACTION PRODUCTS OF PARA-DIISOPROPYL BENZENE DI-HYDROPEROXIDE IN THE PRESENCE OF AN ACID IS NEUTRALIZED WITH AN ALKALI, THE PRECIPITATED ALKALI SALT OF THE ACID IS FILTERED OFF, THE ACETONE IS DISTILLED OFF, THE RESIDUE IS EXTRACTED WITH AN ALIPHATIC HALOGENATED HYDROCARBON, AND FINALLY, THE RESULTING HYDROQUINONE IS SEPARATED FROM THE RESIDUAL AQUEOUS SOLUTION LEFT ON THE EXTRACTION.
Inventors
- 👤 M Sugiyama
- 👤 Y Nishigaki
- 👤 S Itagaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:56
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/68; C07C37/86; C07C37/685; C07C37/70; C07C37/72
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |