US3093589A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic material
Assignee: Columbian Carbon Co
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Filing: 1961-05-11
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Granted: 1963-06-11
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Expires: 1981-05-11
Abstract
No abstract record available.
Inventors
- 👤 Charles D Downs
- 👤 Martin John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:40
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2683
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
137 words
PROCESS FOR PRODUCING AN IMPROVED BARIUM FERRITE ESPECIALLY ADAPTED TO USE IN THE MAKING PERMANENT MAGNETS WHICH COMPRISES CALCINING AT A TEMPERATURE OF 1600*1800*F. FOR FROM 10 TO 30 MINUTES AN INTIMATE UNIFORM MIXTURE OF FINELY DIVIDED BARIUM CARBONATE AND A FINELY DIVIDED FERRIC OXIDE HAVING AN ACICULAR STRUCTURE, IN PROPORTIONS WITHIN THE RANGE EQUIVALENT TO ONE MOL BAO TO 5.9-6.4 MOLS FE2O3 AND A CATALYTIC AMOUNT OF A CHLORIDE CATALYST, WHICH IS VOLATILE AT THE CALCINING TEMPERATURE EQUIVALENT TO NOT LESS THAN ABOUT 0.1% NOR MORE THAN ABOUT 1% OF BARIUM CHLORIDE ON THE WEIGHT OF THE SOLIDS, THE PARTICLES OF THE FERRIC OXIDE USED HAVING AN AVERAGE LENGTH OF 0.5-2.5 MICRONS AND AN AVERAGE DIAMETER OF 0.1-0.5 MICRON, THE AVERAGE RATIO OF LENGTH TO DIAMETER BEING WITHIN THE RANGE FROM ABOUT 2:1 TO ABOUT 5:1.
Claim 2
Dependent Claim
137 words
PROCESS FOR PRODUCING AN IMPROVED BARIUM FERRITE ESPECIALLY ADAPTED TO USE IN THE MAKING PERMANENT MAGNETS WHICH COMPRISES CALCINING AT A TEMPERATURE OF 1600*1800*F. FOR FROM 10 TO 30 MINUTES AN INTIMATE UNIFORM MIXTURE OF FINELY DIVIDED BARIUM CARBONATE AND A FINELY DIVIDED FERRIC OXIDE HAVING AN ACICULAR STRUCTURE, IN PROPORTIONS WITHIN THE RANGE EQUIVALENT TO ONE MOL BAO TO 5.9-6.4 MOLS FE2O3 AND A CATALYTIC AMOUNT OF A CHLORIDE CATALYST, WHICH IS VOLATILE AT THE CALCINING TEMPERATURE EQUIVALENT TO NOT LESS THAN ABOUT 0.1% NOR MORE THAN ABOUT 1% OF BARIUM CHLORIDE ON THE WEIGHT OF THE SOLIDS, THE PARTICLES OF THE FERRIC OXIDE USED HAVING AN AVERAGE LENGTH OF 0.5-2.5 MICRONS AND AN AVERAGE DIAMETER OF 0.1-0.5 MICRON, THE AVERAGE RATIO OF LENGTH TO DIAMETER BEING WITHIN THE RANGE FROM ABOUT 2:1 TO ABOUT 5:1.
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) | 1966-06-10 | 1966-12-10 | 1967-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-06-10 | 1970-12-10 | 1971-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-06-10 | 1974-12-10 | 1975-06-11 | $7700.00 | Window Closed / Lapsed |