US4438179A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resin particles with magnetic particles bonded to surface
Assignee: Dow Chemical Co
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Filing: 1982-02-03
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Granted: 1984-03-20
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Expires: 2002-02-03
Abstract
Abstract Plastic particles having diameters of from about 1 to about 150 microns, a polymeric bonding layer on the surface thereof, are coated with magnetic particles to provide a generally uniform coating having a thickness of from about 0.05 to about 0.8 of a micron.
Inventors
- 👤 Jitka Solc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:20
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/06; H01F1/063; H01F1/0027; H01F1/12; H01F1/14; H01F1/20; H01F1/34; H01F1/36; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
55 words
A synthetic resinous particle having a diameter of from about 1-150 microns, the particle having bonded to the surface thereof a coating comprising a magnetic layer, the magnetic layer being of flocculated magnetic particles being bonded to the surface thereof, the bonding layer comprising a water swellable polymer grafted to the surface of the particle.
Claim 2
Dependent Claim
55 words
A synthetic resinous particle having a diameter of from about 1-150 microns, the particle having bonded to the surface thereof a coating comprising a magnetic layer, the magnetic layer being of flocculated magnetic particles being bonded to the surface thereof, the bonding layer comprising a water swellable polymer grafted to the surface of the particle.
Claim 3
Dependent Claim
57 words
A synthetic resinous particle having a diameter of from about 1 to 150 microns, the particle having a bonding layer of a water swellable polymer grafted to the surface of the particle, the bonding layer bonding a layer of flocculated colloidal magnetic iron oxide particles to thereby form a magnetic layer on the surface of the particle.
Claim 4
Dependent Claim
57 words
A synthetic resinous particle having a diameter of from about 1 to 150 microns, the particle having a bonding layer of a water swellable polymer grafted to the surface of the particle, the bonding layer bonding a layer of flocculated colloidal magnetic iron oxide particles to thereby form a magnetic layer on the surface of the particle.
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) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |