US3036889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of producing black oxide of iron
Assignee: Individual
•
Filing: 1958-04-01
•
Granted: 1962-05-29
•
Expires: 1978-04-01
Abstract
No abstract record available.
Inventors
- 👤 Frey Friedrich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:17
CPC Classifications
C; C01; C01G; C01G49/00; C01G49/02; C01G49/08; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/60
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
113 words
A PROCESS OF PRODUCING BLACK IRON OXIDE PIGMENT, COMPRISING THE STEPS OF SUBJECTING SUBSTANTIALLY DRY FERRIC OXIDE-CONTAINING CONVERTER DUST HAVING A PARTICLE SIZE CORRESPONDING TO THE PARTICLE SIZE OF SAID BLACK IRON OXIDE PIGMENT AND BEING ABOVE COLLOIDAL DIMENSIONS BUT NOT EXCEEDING 5 MICRONS, IN THE PRESENCE OF A REDUCING AGENT ADAPTED TO REDUCE FERRIC OXIDE AT ELEVATED TEMPERATURES TO FERROSO-FERRIC OXIDE, TO SAID ELEVATED TEMPERATURE FOR A PERIOD OF TIME SUFFICIENT TO SUBSTANTIALLY REDUCE SAID FERRIC OXIDE OF SAID CONVERTER DUST TO FERROSO-FERRIC OXIDE; AND COOLING THE THUS OBTAINED MATERIAL BELOW THE TEMPERATURE AT WHICH SAID FERROSO-FERRIC OXIDE IS RE-OXIDIZED TO FERRIC OXIDE, WHEREBY A STABLE BLACK IRON OXIDE PIGMENT IS OBTAINED.
Claim 2
Dependent Claim
113 words
A PROCESS OF PRODUCING BLACK IRON OXIDE PIGMENT, COMPRISING THE STEPS OF SUBJECTING SUBSTANTIALLY DRY FERRIC OXIDE-CONTAINING CONVERTER DUST HAVING A PARTICLE SIZE CORRESPONDING TO THE PARTICLE SIZE OF SAID BLACK IRON OXIDE PIGMENT AND BEING ABOVE COLLOIDAL DIMENSIONS BUT NOT EXCEEDING 5 MICRONS, IN THE PRESENCE OF A REDUCING AGENT ADAPTED TO REDUCE FERRIC OXIDE AT ELEVATED TEMPERATURES TO FERROSO-FERRIC OXIDE, TO SAID ELEVATED TEMPERATURE FOR A PERIOD OF TIME SUFFICIENT TO SUBSTANTIALLY REDUCE SAID FERRIC OXIDE OF SAID CONVERTER DUST TO FERROSO-FERRIC OXIDE; AND COOLING THE THUS OBTAINED MATERIAL BELOW THE TEMPERATURE AT WHICH SAID FERROSO-FERRIC OXIDE IS RE-OXIDIZED TO FERRIC OXIDE, WHEREBY A STABLE BLACK IRON OXIDE PIGMENT IS OBTAINED.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-05-28 | 1965-11-27 | 1966-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-05-28 | 1969-11-27 | 1970-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-05-28 | 1973-11-27 | 1974-05-29 | $7700.00 | Window Closed / Lapsed |