US4282304A
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
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Filing: 1979-10-22
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Granted: 1981-08-04
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Expires: 1999-10-22
Abstract
Abstract Toner particles are prepared by a dispersion polymerization technique wherein monomer present in the discontinuous phase is removed after sizing of the monomer droplets to thereby increase the weight ratio of magnetic particles present in the completed toner particles.
Inventors
- 👤 Robert D. Bayley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:34
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0802; G03G9/0804; G03G9/0806
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
83 words
A method of making magnetic toner particles by a dispersion polymerization technique comprising dispersing magnetic particles and a polymerization initiator in a vinyl monomer, sizing the monomer by forming a suspension of toner size droplets in an aqueous medium containing a stabilizing agent, removing monomer from the sized droplets subsequent to formation of the suspension whereby the concentration of magnetic particles in the polymerized particles is increased to greater than 45 percent by weight and separating the polymerized particles from the reaction mixture.
Claim 2
Independent Claim
83 words
A method of making magnetic toner particles by a dispersion polymerization technique comprising dispersing magnetic particles and a polymerization initiator in a vinyl monomer, sizing the monomer by forming a suspension of toner size droplets in an aqueous medium containing a stabilizing agent, removing monomer from the sized droplets subsequent to formation of the suspension whereby the concentration of magnetic particles in the polymerized particles is increased to greater than 45 percent by weight and separating the polymerized particles from the reaction mixture.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein the monomer is removed from the sized droplets, prior to the polymerizing step.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein the monomer is removed from the sized droplets during the polymerizing step.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein the monomer is removed from the sized droplets bath before and during the polymerization step.
Claim 6
Dependent Claim
25 words
The method of claim 1 wherein the original concentration of magnetic particles in the monomer is from about 40 to about 45 percent by weight.
Claim 7
Dependent Claim
23 words
The method of claim 1 wherein the droplet size of the monomer containing magnetic particles is from about 5 to about 30 microns.
Claim 8
Dependent Claim
11 words
The method of claim 1 wherein the magnetic particles are magnetite.
Claim 9
Dependent Claim
23 words
The method of claim 1 wherein the volumetric ratio of the continuous phase to aqueous phase is from about 0.05 to about 1:1.
Claim 10
Dependent Claim
16 words
The method of claim 5 wherein the volumetric ratio is from about 0.1:1 to about 0.5:1.
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) | 1984-08-03 | 1985-02-02 | 1985-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-03 | 1989-02-02 | 1989-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-03 | 1993-02-02 | 1993-08-04 | $7700.00 | Window Closed / Lapsed |