Patent US2839408A successfully refreshed from Google Patents.
US2839408A
Expired / Lapsed
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Method of producing condensed phosphoric acids
Assignee: Monsanto Chemicals Ltd
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Filing: 1957-03-04
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Granted: 1958-06-17
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Expires: 1977-03-04
Abstract
No abstract record available.
Inventors
- 👤 Edward J Griffith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:04
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
31 words
THE METHOD OF PREPARING A CONDENSED PHOSPHORIC ACID BY PASSING DIRECT CURRENT BETWEEN NON-REACTIVE ELECTRODES THROUGH A LESS CONDENSED PHOSPHORIC ACID HAVING A MOLE RATIO OF H2O/P2O NOT GREATER THAN 3.
Claim 2
Independent Claim
31 words
THE METHOD OF PREPARING A CONDENSED PHOSPHORIC ACID BY PASSING DIRECT CURRENT BETWEEN NON-REACTIVE ELECTRODES THROUGH A LESS CONDENSED PHOSPHORIC ACID HAVING A MOLE RATIO OF H2O/P2O NOT GREATER THAN 3.
References Cited (Backward Citations)
US1658222A
Cited
US1873457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-16 | 1961-12-16 | 1962-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-16 | 1965-12-16 | 1966-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-16 | 1969-12-16 | 1970-06-17 | $7700.00 | Window Closed / Lapsed |