Patent US3977871A successfully refreshed from Google Patents.
US3977871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic developer with fibers of polytetrafluoroethylene
Assignee: International Business Machines Corp
•
Filing: 1975-08-15
•
Granted: 1976-08-31
•
Expires: 1995-08-15
Abstract
Abstract The formation of toner film on the photoconductor in electrophotography is reduced by adding to the developer toner a small amount of fibrillatable polytetrafluoroethylene, and working the mixture until a random network of fibers of said polytetrafluoroethylene is formed.
Inventors
- 👤 Walter Crooks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:01
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/087; G03G9/08702; G03G9/08713; G03G9/0872
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
97 words
In an electrophotographic process wherein an electrostatic image is made visible by contacting the surface bearing said image with finally divided toner particles of thermoplastic resin containing coloring material, the improvement according to which toner filming of the image bearing surface is reduced by incorporating in the toner in an amount from about 0.01% up to 10% by weight of the toner an additive of fine powder type polytetrafluoroethylene dispersed throughout said toner in the form of a random network of fibers, said fine powder type polytetrafluoroethylene having been obtained by coagulation of a colloidal acqueous dispersion.
Claim 2
Dependent Claim
97 words
In an electrophotographic process wherein an electrostatic image is made visible by contacting the surface bearing said image with finally divided toner particles of thermoplastic resin containing coloring material, the improvement according to which toner filming of the image bearing surface is reduced by incorporating in the toner in an amount from about 0.01% up to 10% by weight of the toner an additive of fine powder type polytetrafluoroethylene dispersed throughout said toner in the form of a random network of fibers, said fine powder type polytetrafluoroethylene having been obtained by coagulation of a colloidal acqueous dispersion.
Claim 3
Dependent Claim
15 words
A process as claimed in claim 1 wherein the amount of polytetrafluoroethylene is about 1.5%.
Claim 4
Dependent Claim
60 words
A developer composition for electrophotography comprising finely divided toner particles of thermoplastic resin containing coloring matter, and, in an amount from about 0.01% up to 10% by weight of the toner, a random network of fibers of fine powder type polytetrafluoroethylene dispersed throughout said toner, said fine powder type polytetrafluoroethylene having been obtained by coagulation of a colloidal aqueous dispersion.
Claim 5
Dependent Claim
60 words
A developer composition for electrophotography comprising finely divided toner particles of thermoplastic resin containing coloring matter, and, in an amount from about 0.01% up to 10% by weight of the toner, a random network of fibers of fine powder type polytetrafluoroethylene dispersed throughout said toner, said fine powder type polytetrafluoroethylene having been obtained by coagulation of a colloidal aqueous dispersion.
Claim 6
Dependent Claim
21 words
A developer composition as claimed in claim 1 wherein the polytetrafluoroethylene is present in approximately 1.5% by weight of the toner.
References Cited (Backward Citations)
US2297691A
Cited
US2559752A
Cited
US2965573A
Cited
US3236776A
Cited
GB1233869A
Cited
US3873355A
Cited
US3838092A
Cited
US3838064A
Cited
US3850631A
Cited
US3900588A
Cited
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 |