US4198307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymer based magnetic tags
Assignee: Lockheed Martin Corp
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Filing: 1978-07-24
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Granted: 1980-04-15
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Expires: 1998-07-24
Abstract
Abstract Ferrite particles having a plurality of distinct Curie temperatures are encapsulated within a polymer matrix to provide tagging material especially useful in identifying explosive materials even after detonation. In one embodiment, phosphor is dispersed within the polymer matrix to facilitate collection of tag particles following detonation. The tags are also usable in tagging other articles, especially where harsh environmental conditions are likely to be encountered.
Inventors
- 👤 Ami E. Berkowitz
- 👤 Fred F. Holub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:30
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/34; H01F1/36; H01F1/37; C; C06; C06B; C06B23/00; C06B23/008; Y; Y10; Y10S; Y10S149/00; Y10S149/123
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
34 words
A magnetic tag for identification comprising: a plurality of magnetic particles, collectively exhibiting at least one Curie temperature, said magnetic particles being disposed within a polymer matrix particle having a relatively smooth exterior surface.
Claim 2
Dependent Claim
34 words
A magnetic tag for identification comprising: a plurality of magnetic particles, collectively exhibiting at least one Curie temperature, said magnetic particles being disposed within a polymer matrix particle having a relatively smooth exterior surface.
Claim 3
Dependent Claim
13 words
The tag of claim 1 in which the polymer matrix contains a phosphor.
Claim 4
Dependent Claim
15 words
The tag of claim 2 in which the phosphor is yttrium vanadate doped with europium.
Claim 5
Dependent Claim
15 words
The tag of claim 2 in which the phosphor is zinc silicate doped with manganese.
Claim 6
Dependent Claim
14 words
The tag of claim 1 in which the polymer is a curable polysiloxane resin.
Claim 7
Dependent Claim
16 words
The tag of claim 1 in which the polymer is a curable copolymer of polysiloxane resin.
Claim 8
Dependent Claim
20 words
The tag of claim 1 in which the polymer particles are between approximately 100 microns and 5,000 microns in diameter.
Claim 9
Dependent Claim
22 words
The magnetic tag of claim 1 further comprising an adhesive coating for attachment of the tag to a product to be identified.
Claim 10
Dependent Claim
14 words
The magnetic tag of claim 1 in which said polymer matrix includes fumed silica.
Claim 11
Dependent Claim
14 words
The magnetic tag of claim 1 in which the magnetic particles comprise ferrite particles.
Claim 12
Dependent Claim
26 words
The tagging system of claim 10 in which the ferrite particles are composed of material selected from the group consisting of nickel-zinc ferrites and cobalt-zinc ferrites.
Claim 13
Dependent Claim
36 words
A magnetic tag for identification comprising: a mixture of polymer matrix particles with ferrite particles disposed therein, each individual polymer matrix particle exhibiting a single Curie temperature, said mixture exhibiting a plurality of distinct Curie temperatures.
Claim 14
Dependent Claim
36 words
A magnetic tag for identification comprising: a mixture of polymer matrix particles with ferrite particles disposed therein, each individual polymer matrix particle exhibiting a single Curie temperature, said mixture exhibiting a plurality of distinct Curie temperatures.
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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) | 1983-04-15 | 1983-10-15 | 1984-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-15 | 1987-10-15 | 1988-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-15 | 1991-10-15 | 1992-04-15 | $7700.00 | Window Closed / Lapsed |