US3755554A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of iron oxide and hydrated iron oxide pigments
Assignee: Bayer AG
•
Filing: 1971-05-25
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Granted: 1973-08-28
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Expires: 1991-05-25
Abstract
Abstract TREATMENT OF METALLIC IRON CONTAINING MATERIAL WITH OXYGEN CONTAINING GASES IN THE PRESENCE OF AN AQUEOUS SLIGHTLY ACID FERROUS SALT SOLUTION CHARACTERIZED BY ADDITION OF THE METALLIC IRON CONTAINING MATERIAL AS A FINELY DIVIDED POWER INTO THE REACTION MIXTURE AT A RATE MAINTAINING THE PH BETWEEN 1 AND 6, PREFERRABLY BETWEEN 6 AND 6. MODIFYING SUBSTANCES SUCH AS A-FEOOH, Y-FEOOH, $-FEOOH AND A-FE2O3 MAY BE EMPLOYED.
Inventors
- 👤 G Lailach
- 👤 F Rodi
- 👤 H Bade
- 👤 H Koeller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:46
CPC Classifications
C; C01; C01G; C01G49/00; C01G49/02; C01G49/06; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2004/62
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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |