US4390461A
Expired / Lapsed
US
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Ferrite electrode material
Assignee: Hitachi Ltd
•
Filing: 1981-04-03
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Granted: 1983-06-28
•
Expires: 2001-04-03
Abstract
Abstract A ferrite electrode material composed principally of a composition comprising barium oxide and iron oxide and having been calcined with heating in an inert gas atmosphere is excellent in minimizing energy loss and suppressing high-frequency noise.
Inventors
- 👤 Nobuyoshi Tsukiyama
- 👤 Ryo Ichige
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:29
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/10; C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/2683
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
49 words
A ferrite electrode material consisting essentially of a calcined mixture of metal oxides of the formulation (BaO) n .(Fe 2 O 3 ) m or (BaO) n .(FeO.Fe 2 O 3 ) m , wherein n is 0.6 to 1.0 and m is 0.8 to 1.2 in molar ratio.
Claim 2
Dependent Claim
49 words
A ferrite electrode material consisting essentially of a calcined mixture of metal oxides of the formulation (BaO) n .(Fe 2 O 3 ) m or (BaO) n .(FeO.Fe 2 O 3 ) m , wherein n is 0.6 to 1.0 and m is 0.8 to 1.2 in molar ratio.
Claim 3
Dependent Claim
40 words
A ferrite electrode material according to claim 1, wherein said mixture of metal oxides is (BaO) n .(Fe 2 O 3 ) m , in which n is 0.6 to 1.0 and m is 0.8 to 1.2 in molar ratio.
Claim 4
Dependent Claim
53 words
A ferrite electrode material according to claim 1, wherein said mixture of metal oxides is (BaO) n .(FeO.Fe 2 O 3 ) m , in which n is 0.6 to 1.0 and m is 0.8 to 1.2 in molar ratio and the molar ratio of FeO/Fe 2 O 3 is 1/2 to 1/5.
Claim 5
Dependent Claim
29 words
A ferrite electrode material according to claim 1, wherein the weight ratio of barium oxide is about 0.5 based on the total weight of barium oxide and iron oxide.
Claim 6
Dependent Claim
29 words
A ferrite electrode material according to claim 3, wherein (BaO) n .(FeO.Fe 2 O 3 ) m is (BaO) 0 .8.(FeO) 0 .2.(Fe 2 O 3 ) 1 .0.
Claim 7
Dependent Claim
45 words
A ferrite electrode material according to claim 1, wherein the calcined mixture is produced by calcining a pulverized mixture of barium oxide and iron oxide or iron oxides at a temperature of 1100°-1250° C. in an inert gas contaning less than 0.01 ppm of oxygen.
Claim 8
Dependent Claim
65 words
A ferrite electrode material according to claim 1, wherein the calcined mixture is produced by calcining a pulverized mixture of barium oxide and iron oxide or iron oxides at a temperature of 1100°-1200° C., pulverizing and mixing the calcined mixture, and re-calcining at a temperature of 1200°-1250° C., the calcining the re-calcining taking place in an inert gas containing less than 0.01 ppm of oxygen.
Claim 9
Dependent Claim
16 words
A ferrite electrode material according to claim 6 or 7, wherein the inert gas is argon.
Claim 10
Dependent Claim
28 words
A ferrite electrode material according to claim 1, wherein the calcined mixture is produced by calcining in an inert gas atmosphere containing less than 0.01 ppm of oxygen.
Claim 11
Dependent Claim
14 words
A ferrite electrode material according to claim 1, which consists of said calcined mixture.
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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) | 1986-06-27 | 1986-12-27 | 1987-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-27 | 1990-12-27 | 1991-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-27 | 1994-12-27 | 1995-06-28 | $7700.00 | Window Closed / Lapsed |