US4113641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carrier particles having the surface thereof treated with perfluoro sulfonic acid and method of making the same
Assignee: Pitney Bowes Inc
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Filing: 1977-10-07
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Granted: 1978-09-12
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Expires: 1997-10-07
Abstract
Abstract It has been found that unexpectedly high charge to mass ratios may be achieved in a development powder if the carrier particle of the development powder is treated with a perfluoroalkyl sulfonic acid. Treating carrier particles with a monolayer of such an acid has produced charge to mass ratios of 20 to 26 × 10 -6 coulombs/gm. The acid concentration in of the solution used in this treatment has been found to be critical.
Inventors
- 👤 George Brana
- 👤 John J. Russell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:07
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1138; B; B82; B82Y; B82Y30/00; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
36 words
A carrier for electrophotographic development of latent electrostatic images, comprising particles selected from the group consisting of metal particles and metallic particles, said particles having adhered to the surface thereof a layer of perfluoroalkyl sulfonic acid.
Claim 2
Dependent Claim
36 words
A carrier for electrophotographic development of latent electrostatic images, comprising particles selected from the group consisting of metal particles and metallic particles, said particles having adhered to the surface thereof a layer of perfluoroalkyl sulfonic acid.
Claim 3
Dependent Claim
20 words
The carrier of claim 1 wherein said carrier particles have a monolayer of said acid adhering to the surface thereof.
Claim 4
Dependent Claim
20 words
The carrier of claim 1 wherein said carrier particles are selected from the group consisting of iron, nickel and aluminum.
Claim 5
Dependent Claim
57 words
In a method of treating a metal or metallic electrostatic carrier particle with a perfluoroalkyl sulfonic acid, the step comprising: a. preparing a perfluoroalkyl sulfonic acid-solvent solution having a 0.001-0.030 concentration of a fluorinated sulfonic acid; b. adding the carrier particles to the solution; c. mixing the carrier particles within said solution; and d. evaporating the solution.
Claim 6
Dependent Claim
57 words
In a method of treating a metal or metallic electrostatic carrier particle with a perfluoroalkyl sulfonic acid, the step comprising: a. preparing a perfluoroalkyl sulfonic acid-solvent solution having a 0.001-0.030 concentration of a fluorinated sulfonic acid; b. adding the carrier particles to the solution; c. mixing the carrier particles within said solution; and d. evaporating the solution.
Claim 7
Dependent Claim
27 words
The method of claim 5 wherein the concentration of the solution is controlled to provide a monolayer about the carrier particles following the evaporation of the solution.
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) | 1981-09-11 | 1982-03-13 | 1982-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-11 | 1986-03-13 | 1986-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-11 | 1990-03-13 | 1990-09-12 | $7700.00 | Window Closed / Lapsed |