Patent US2938770A successfully refreshed from Google Patents.
US2938770A
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Process for the purification of alkali metal hypophosphite solutions containing alkali metal phosphites
Assignee: La Fonte Electrique SA
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Filing: 1958-06-02
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Granted: 1960-05-31
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Expires: 1978-06-02
Abstract
No abstract record available.
Inventors
- 👤 Pahud Rene
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:56
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
99 words
A PROCESS FOR THE PURIFICATION OF AN AQUEOUS ALKALI METAL HYPOPHOSPHITE SOLUTION CONTAINING AN ALKALI METAL PHOSPHITE IN WHICH THE PHOSPHITE IONS ARE PRECIPITATED AS INSOLUBLE ALKALINE EARTH METAL PHOSPHITE BY THE ADDITION OF AN AQUEOUS SOLUTION OF AN ALKALINE EARTH METAL HYPOPHOSPHITE IN AN AMOUNT STOICHIOMETRICALLY EQUIVALENT TO THE AMOUNT OF ALKALI METAL PHOSPHITE IN THE SOLUTION TO BE PURIFIED, THE SAID AQUEOUS SOLUTION OF ALKALINE EARTH METAL HYPOPHOSPHITE HAVING BEEN PREPARED FROM A CONCENTRATED AQUEOUS SOLUTION OF ALKALI METAL HYPOPHOSPHITE BY TREATMENT WITH A CATION EXCHANGER WHEREBY ALKALI METAL IONS ARE SUBSTITUTED BY ALKALINE EARTH METAL IONS.
Claim 2
Dependent Claim
99 words
A PROCESS FOR THE PURIFICATION OF AN AQUEOUS ALKALI METAL HYPOPHOSPHITE SOLUTION CONTAINING AN ALKALI METAL PHOSPHITE IN WHICH THE PHOSPHITE IONS ARE PRECIPITATED AS INSOLUBLE ALKALINE EARTH METAL PHOSPHITE BY THE ADDITION OF AN AQUEOUS SOLUTION OF AN ALKALINE EARTH METAL HYPOPHOSPHITE IN AN AMOUNT STOICHIOMETRICALLY EQUIVALENT TO THE AMOUNT OF ALKALI METAL PHOSPHITE IN THE SOLUTION TO BE PURIFIED, THE SAID AQUEOUS SOLUTION OF ALKALINE EARTH METAL HYPOPHOSPHITE HAVING BEEN PREPARED FROM A CONCENTRATED AQUEOUS SOLUTION OF ALKALI METAL HYPOPHOSPHITE BY TREATMENT WITH A CATION EXCHANGER WHEREBY ALKALI METAL IONS ARE SUBSTITUTED BY ALKALINE EARTH METAL IONS.
References Cited (Backward Citations)
US2595199A
Cited
US2843457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-05-31 | 1963-11-30 | 1964-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-31 | 1967-11-30 | 1968-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-31 | 1971-11-30 | 1972-05-31 | $7700.00 | Window Closed / Lapsed |