US3576598A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of sodium hydrosulfite from formates
Assignee: Hoechst Celanese Chemical Co
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Filing: 1970-02-05
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Granted: 1971-04-27
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Expires: 1990-02-05
Abstract
Abstract METHOD FOR THE PRODUCTION OF ANHYDROUS SODIUM HYDROSULFITE (NA2S2O4) BY FEEDING TOGETHER INTO A REACTOR CONTAINING A WATER-MISCIBLE ALCOHOL (1) A SOLUTION OF SULFUR DIXOIDE (SO2) AND A WATER-MISCIBLE ALCOHOL AND (2) A SOLUTION OF SODIUM HYDROXIDE (NAOH) AND SODIUM FORMATE (HCOONA) IN WATER (H2O), STIRRING AND HEATING UNDER PRESSURE WHILE VENTING CARBON DIOXIDE (CO2) AND COOLING AND RECOVERING THE HYDROSULFITE BY FILTRATION.
Inventors
- 👤 Jack Plentovich
- 👤 Charles Ellis Winslow Jr
- 👤 Mearl A Kise
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:33
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/64; C01B17/66
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) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |