US4272285A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing magnetic metal powders
Assignee: TDK Corp
•
Filing: 1980-07-11
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Granted: 1981-06-09
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Expires: 2000-07-11
Abstract
Abstract In a process for producing a magnetic metal powder, a magnetic metal compound is reduced by wet reduction in a state mixed with a clay or is heat treated in the presence of a clay powder. Alternatively, a magnetic metal powder is prepared by reducing a magnetic metal powder by wet reduction or by reducing a magnetic metal compound in a state mixed with a clay by dry reduction, and then the resulting powder is heat treated in the presence of the clay powder. The clay is typically kaolin.
Inventors
- 👤 Rioichi Horimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:36
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/06; H01F1/065; B; B22; B22F; B22F1/00; B22F1/14; B22F1/142
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
25 words
A process for producing a magnetic metal powder which comprises reducing a magnetic metal compound in a state mixed with a clay by dry reduction.
Claim 2
Dependent Claim
25 words
A process for producing a magnetic metal powder which comprises reducing a magnetic metal compound in a state mixed with a clay by dry reduction.
Claim 3
Dependent Claim
23 words
A process for producing a magnetic metal powder which comprises heat treating a magnetic metal powder in the presence of a clay powder.
Claim 4
Dependent Claim
23 words
A process for producing a magnetic metal powder which comprises heat treating a magnetic metal powder in the presence of a clay powder.
Claim 5
Dependent Claim
31 words
A process for producing a magnetic metal powder which comprises preparing a magnetic metal powder by wet reduction and then heat treating the same in the presence of a clay powder.
Claim 6
Dependent Claim
31 words
A process for producing a magnetic metal powder which comprises preparing a magnetic metal powder by wet reduction and then heat treating the same in the presence of a clay powder.
Claim 7
Dependent Claim
44 words
A process for producing a magnetic metal powder which comprises preparing a magnetic metal powder by reducing a magnetic metal compound in a state mixed with a clay by dry reduction and then heat treating said powder in the presence of the clay powder.
Claim 8
Dependent Claim
44 words
A process for producing a magnetic metal powder which comprises preparing a magnetic metal powder by reducing a magnetic metal compound in a state mixed with a clay by dry reduction and then heat treating said powder in the presence of the clay powder.
Claim 9
Dependent Claim
15 words
A process according to any of claims 1 through 4, wherein said clay is kaolin.
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) | 1984-06-08 | 1984-12-08 | 1985-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-08 | 1988-12-08 | 1989-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-08 | 1992-12-08 | 1993-06-09 | $7700.00 | Window Closed / Lapsed |