US3411875A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of anhydrous hydrosulfites
Assignee: Mitsubishi Edogawa Kagaku KK
•
Filing: 1965-04-01
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Granted: 1968-11-19
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Expires: 1985-04-01
Abstract
No abstract record available.
Inventors
- 👤 Yoshikawa Yoshio
- 👤 Okazaki Heizo
- 👤 Yamaguchi Takaaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:46
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/64; C01B17/66
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
56 words
PROCESS FOR THE PRODUCTION OF ANHYDROUS ALKALI METAL HYDROSULFITE WHICH COMPRISES ADDING DROPWISE SULFUR DIOXIDE CONTAINING METHANOL AND AN ALKALINE AGENT TO AN AQUEOUS SOLUTION OF ALKALI METAL FORMATE, AT A TEMPERATURE, BETWEEN THE ANHYDROUS-HYDRATE TRASITION POINT OF ALKALI METAL HYDROSULFITE AND THE REFLUX TEMPERATURE OF THE REACTION MIXTURE AT A PH BETWEEN 4 AND 6.5.
Claim 2
Dependent Claim
56 words
PROCESS FOR THE PRODUCTION OF ANHYDROUS ALKALI METAL HYDROSULFITE WHICH COMPRISES ADDING DROPWISE SULFUR DIOXIDE CONTAINING METHANOL AND AN ALKALINE AGENT TO AN AQUEOUS SOLUTION OF ALKALI METAL FORMATE, AT A TEMPERATURE, BETWEEN THE ANHYDROUS-HYDRATE TRASITION POINT OF ALKALI METAL HYDROSULFITE AND THE REFLUX TEMPERATURE OF THE REACTION MIXTURE AT A PH BETWEEN 4 AND 6.5.
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) | 1971-11-19 | 1972-05-20 | 1972-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-11-19 | 1976-05-20 | 1976-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-11-19 | 1980-05-20 | 1980-11-19 | $7700.00 | Window Closed / Lapsed |