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US3933536A
Expired / Lapsed
US
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Method of making magnets by polymer-coating magnetic powder
Assignee: General Electric Co
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Filing: 1972-11-03
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Granted: 1976-01-20
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Expires: 1992-11-03
Abstract
Abstract Magnets are produced by dissolving in a solvent organic polymer which is a binder for magnetic powder, adding a magnetic powder to the solution, then adding to the solution a vehicle in which the polymer is insoluble. The vehicle is added until the polymer has precipitated onto the magnetic particles. These coated particles are then dried and hot pressed within an orienting magnetic field to produce the magnet.
Inventors
- 👤 Manfred Doser
- 👤 Daniel Edwin Floryan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:10
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/0551; H01F1/0552; Y; Y10; Y10S; Y10S264/00; Y10S264/58
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
64 words
The method of making a permanent magnet which comprises: dissolving in a solvent an organic polymer which is a binder for magnetic particles; adding particles of magnetic powder to the resulting solution; adding to said solution a vehicle in which said polymer is insoluble until the polymer precipitates onto the particles; and hot pressing the polymer-coated particles into a compact to form a magnet.
Claim 2
Independent Claim
64 words
The method of making a permanent magnet which comprises: dissolving in a solvent an organic polymer which is a binder for magnetic particles; adding particles of magnetic powder to the resulting solution; adding to said solution a vehicle in which said polymer is insoluble until the polymer precipitates onto the particles; and hot pressing the polymer-coated particles into a compact to form a magnet.
Claim 3
Dependent Claim
22 words
The method of claim 1 in which the magnetic particles are selected from the group consisting of cobalt-rare earth and alnico particles.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein the hot pressing step is carried out within an orienting magnetic field.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein the binder is a polycarbonate resin.
Claim 6
Dependent Claim
17 words
The method of claim 4 wherein the solvent is methylene chloride and the vehicle is methyl alcohol.
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) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |