US3977984A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemically reactive resin beads and to methods of their manufacture
Assignee: US Philips Corp
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Filing: 1975-10-23
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Granted: 1976-08-31
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Expires: 1995-10-23
Abstract
Abstract Resin beads impregnated with magnetic powder, e.g. barium ferrite or γ-iron oxide magnetically aligned and located discretely with respect to each other are formed by suspending the beads in a liquid while polymerizing the resin and subjecting the beads to an aligning magnetic field during a portion of the process of polymerization of the resin at which the resin viscosity is sufficient to permit rotation of the magnetic particles and yet sufficiently high to prevent lateral movement, and hence clumping of the magnetic particles, e.g. a molecular weight range of between 1,000 and 10,000 and a viscosity of between 5 and 50 poise.
Inventors
- 👤 Roy Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:32
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/10; H01F1/11; H01F1/113; B; B01; B01J; B01J47/00; B01J47/016
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
58 words
A material comprising resin beads of a condensation polymers selected from the group consisting of polyethylenimine-epichlorohydrin polymer and phenolformaldehyde polymers impregnated with particles of a ferromagnetic material selected from the group consisting of γ-ferricoxide and barium ferrite, magnetically aligned and located discretely with respect to each other when the polymer has a molecular weight between 1000 and 10,000.
Claim 2
Dependent Claim
58 words
A material comprising resin beads of a condensation polymers selected from the group consisting of polyethylenimine-epichlorohydrin polymer and phenolformaldehyde polymers impregnated with particles of a ferromagnetic material selected from the group consisting of γ-ferricoxide and barium ferrite, magnetically aligned and located discretely with respect to each other when the polymer has a molecular weight between 1000 and 10,000.
Claim 3
Independent Claim
144 words
A method of manufacturing resin beads impregnated with magnetic powder particles magnetically aligned and located discretely with respect to each other comprising the steps of forming beads of a condensation polymer selected from the group consisting of polyethylenimine-epichlorohydrin polymers and phenolformaldehyde polymers impregnated with particles of a ferromagnetic material selected from the group consisting of gamma ferric oxide and barium ferrite, suspending the polymer beads impregnated with the ferromagnetic material in a liquid, polymerizing the resin to harden the same, and subjecting the beads suspended in the liquid to an aligning magnetic field during a portion of the process of polymerization of the polymer when the molecular weight of the polymer is between 1000 and 10,000 and the polymer has a viscosity between 5 and 50 poise to permit rotation of the magnetic particles and prevent lateral movement and hence clumping of magnetic particles.
Claim 4
Independent Claim
144 words
A method of manufacturing resin beads impregnated with magnetic powder particles magnetically aligned and located discretely with respect to each other comprising the steps of forming beads of a condensation polymer selected from the group consisting of polyethylenimine-epichlorohydrin polymers and phenolformaldehyde polymers impregnated with particles of a ferromagnetic material selected from the group consisting of gamma ferric oxide and barium ferrite, suspending the polymer beads impregnated with the ferromagnetic material in a liquid, polymerizing the resin to harden the same, and subjecting the beads suspended in the liquid to an aligning magnetic field during a portion of the process of polymerization of the polymer when the molecular weight of the polymer is between 1000 and 10,000 and the polymer has a viscosity between 5 and 50 poise to permit rotation of the magnetic particles and prevent lateral movement and hence clumping of magnetic particles.
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) | 1979-08-31 | 1980-03-01 | 1980-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-31 | 1984-03-01 | 1984-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-31 | 1988-03-01 | 1988-08-31 | $7700.00 | Window Closed / Lapsed |