US4264700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming magnetic toner particles having a concentration of magnetic particles greater than 45 percent by weight by dispersion polymerization techniques
Assignee: Xerox Corp
•
Filing: 1979-10-22
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Granted: 1981-04-28
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Expires: 1999-10-22
Abstract
Abstract Toner particles are prepared by a dispersion polymerization technique wherein a solvent for the monomer is included in the preparation of the discontinuous phase, and the solvent is removed prior to polymerization to increase the weight ratio of the magnetic particles present in the completed toner particles.
Inventors
- 👤 Robert D. Bayley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:30
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0802; G03G9/0804; G03G9/0806
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
73 words
A method of making magnetic toner particles by dispersion polymerization technique which comprises forming a suspension of a discontinuous phase of toner size droplets in a continuous phase, said discontinuous phase containing a vinyl monomer, a polymerization initiator, magnetic particles and a solvent for the monomer, said continuous phase containing water and a suspension stabilizing agent, removing the solvent from the discontinuous phase, heating the monomer and recovering the thus formed toner particles.
Claim 2
Independent Claim
73 words
A method of making magnetic toner particles by dispersion polymerization technique which comprises forming a suspension of a discontinuous phase of toner size droplets in a continuous phase, said discontinuous phase containing a vinyl monomer, a polymerization initiator, magnetic particles and a solvent for the monomer, said continuous phase containing water and a suspension stabilizing agent, removing the solvent from the discontinuous phase, heating the monomer and recovering the thus formed toner particles.
Claim 3
Dependent Claim
30 words
The method of claim 1 wherein the quantity of magnetic particles based on the weight of vinyl monomer present in the discontinuous phase is greater than 45 percent by weight.
Claim 4
Dependent Claim
21 words
The method of claim 2 wherein the quantity of magnetic particles present is from about 50 to 65 percent by weight.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein the size of both the droplets of the discontinuous phase and the toner particles is from about 5 to about 35 microns.
Claim 6
Dependent Claim
11 words
The method of claim 1 wherein the magnetic particles are magnetite.
Claim 7
Dependent Claim
26 words
The method of claim 1 wherein the weight ratio of solvent to the monomer present in the discontinuous phase is from about 0.5:1 to about 2:1.
Claim 8
Dependent Claim
33 words
The method of claim 1 wherein the solvent for the monomer present in the discontinuous phase is soluble in water and is removed from the discontinuous phase by migration to the aqueous phase.
Claim 9
Dependent Claim
32 words
The method of claim 1 wherein the volumetric ratio of the continuous phase to aqueous phase, prior to removal of the solvent for the monomer is from about 0.05:1 to about 1:1.
Claim 10
Dependent Claim
16 words
The method of claim 8 wherein the volumetric ratio is from about 0.1:1 to about 0.5:1.
References Cited (Backward Citations)
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Cited
US3959153A
Cited
US3893933A
Cited
US4077804A
Cited
US4071670A
Cited
US4148741A
Cited
US4097620A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |