Patent US3424685A successfully refreshed from Google Patents.
US3424685A
Expired / Lapsed
US
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High permeability ferromagnetic ferrite materials
Assignee: TDK Micronas GmbH
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Filing: 1965-03-23
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Granted: 1969-01-28
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Expires: 1985-03-23
Abstract
No abstract record available.
Inventors
- 👤 Andre Pierrot
- 👤 Yves Lescroel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:36
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2658
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
168 words
A METHOD OF MANUFACTURE OF A FERROMAGNETIC FERRITE MATERIAL WHICH INCLUDES FORMING A HOMOGENEOUS INITIAL MIXTURE OF METALLIC OXIDE POWDERS INCLUDING 52.5-54.5 FERRIC OXIDE FE2O3, 29.3-30 MOL PERCENT MANGANESE OXIDE AND 15.5-19.2 MOL PERCENT ZINC OXIDE, TO WHICH IS ADDED AN AMOUNT OF COPPER EXICE BETWEEN 0.05% AND 0.5% BY WEIGHT TOGETHER WITH BETWEEN 0.1% AND 2.0% BY WEIGHT OF AT LEAST ONE OF THE METAL OXIDES: CALCIUM OXIDE, ANTIMONY OXIDE AND VANADIUM OXIDE, THE TOTAL OF ADDITONS BEING AT MOST EQUAL TO 2.5% BY WEIGHT, COMPRESSING THE INITIAL MIXTURE UNDER A PRESSURE OF 1 TO 15 METRIC TONS PER SQUARE CENTIMETRE, AND HEAT TREATING THE COMPRESSED MIXTURE AT A TEMPERATURE BETWEEN 1,200 AND 1,300*C., FOR ABOUT 5 HOURS, IN AN ATMOPHERE OF NITROGEN CONTAINING 1 TO 5 % BY VOLUME OF EXYGEN, FOLLOWED BY COLING IN NITROGEN FOR ABOUT 15 HOURS, THE COMPOSITION OF THE INITIAL MIXTURE BEING SUCH THAT, WITH THE HEAT TREATMENT INDICATED, THE FINAL PORDUCT CONTAINS APPROXIMATELY 50 MOLECULAR PERCENT OF FERRIC OXIDE FE2O3.
Claim 2
Independent Claim
168 words
A METHOD OF MANUFACTURE OF A FERROMAGNETIC FERRITE MATERIAL WHICH INCLUDES FORMING A HOMOGENEOUS INITIAL MIXTURE OF METALLIC OXIDE POWDERS INCLUDING 52.5-54.5 FERRIC OXIDE FE2O3, 29.3-30 MOL PERCENT MANGANESE OXIDE AND 15.5-19.2 MOL PERCENT ZINC OXIDE, TO WHICH IS ADDED AN AMOUNT OF COPPER EXICE BETWEEN 0.05% AND 0.5% BY WEIGHT TOGETHER WITH BETWEEN 0.1% AND 2.0% BY WEIGHT OF AT LEAST ONE OF THE METAL OXIDES: CALCIUM OXIDE, ANTIMONY OXIDE AND VANADIUM OXIDE, THE TOTAL OF ADDITONS BEING AT MOST EQUAL TO 2.5% BY WEIGHT, COMPRESSING THE INITIAL MIXTURE UNDER A PRESSURE OF 1 TO 15 METRIC TONS PER SQUARE CENTIMETRE, AND HEAT TREATING THE COMPRESSED MIXTURE AT A TEMPERATURE BETWEEN 1,200 AND 1,300*C., FOR ABOUT 5 HOURS, IN AN ATMOPHERE OF NITROGEN CONTAINING 1 TO 5 % BY VOLUME OF EXYGEN, FOLLOWED BY COLING IN NITROGEN FOR ABOUT 15 HOURS, THE COMPOSITION OF THE INITIAL MIXTURE BEING SUCH THAT, WITH THE HEAT TREATMENT INDICATED, THE FINAL PORDUCT CONTAINS APPROXIMATELY 50 MOLECULAR PERCENT OF FERRIC OXIDE FE2O3.
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) | 1972-01-28 | 1972-07-29 | 1973-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-01-28 | 1976-07-29 | 1977-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-01-28 | 1980-07-29 | 1981-01-28 | $7700.00 | Window Closed / Lapsed |