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US2935379A
Expired / Lapsed
US
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Manufacture of ferric oxide
Assignee: Columbian Carbon Co
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Filing: 1957-06-13
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Granted: 1960-05-03
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Expires: 1977-06-13
Abstract
No abstract record available.
Inventors
- 👤 Martin John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:27
CPC Classifications
C; C01; C01G; C01G49/00; C01G49/02; C01G49/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
69 words
THE PROCESS FOR PRODUCING PIGMENTARY, RED ALPHA FERRIC OXIDE WHICH COMPRISES DIGESTING GAMMA FERRIC OXIDE IN AQUEOUS SUSPENSION CONTAINING A FERROUS SALT OF A MINERAL ACID IN SOLUTION IN THE AQUEOUS PHASE IN MOLAR CONCENTRATION WITHIN THE RANGE OF 0.1 TO 0.5 MOLS PER LITER, AT A TEMPERATURE WITHIN THE RANGE OF 70* TO 100*C., UNTIL THE GAMMA OXIDE HAS BEEN CONVERTED TO A RED NONMAGNETIC ALPHA FERRIC OXIDE.
Claim 2
Dependent Claim
69 words
THE PROCESS FOR PRODUCING PIGMENTARY, RED ALPHA FERRIC OXIDE WHICH COMPRISES DIGESTING GAMMA FERRIC OXIDE IN AQUEOUS SUSPENSION CONTAINING A FERROUS SALT OF A MINERAL ACID IN SOLUTION IN THE AQUEOUS PHASE IN MOLAR CONCENTRATION WITHIN THE RANGE OF 0.1 TO 0.5 MOLS PER LITER, AT A TEMPERATURE WITHIN THE RANGE OF 70* TO 100*C., UNTIL THE GAMMA OXIDE HAS BEEN CONVERTED TO A RED NONMAGNETIC ALPHA FERRIC OXIDE.
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) | 1963-05-03 | 1963-11-02 | 1964-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-03 | 1967-11-02 | 1968-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-03 | 1971-11-02 | 1972-05-03 | $7700.00 | Window Closed / Lapsed |