US4187329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic developing process and compositions for use therein
Assignee: IBM Information Products Corp
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Filing: 1971-02-03
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Granted: 1980-02-05
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Expires: 1991-02-03
Abstract
Abstract Wetting by toners of the surface of reusable photoconductors in electrophotographic processes results on image cycling in adhesion of the toner to the photoconductor surface to form a film. Such filming is reduced or eliminated by including in the developer a small amount of certain unpigmented organic polymeric materials having smaller particle size than the pigmented toner particles. Suitable organic polymers are fluorinated hydrocarbon polymers and copolymers, and polyethylene.
Inventors
- 👤 Walter Crooks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:47
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/087; G03G9/08702; G03G9/08713; G03G9/0872; G03G9/097
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
99 words
In an electrophotographic process wherein an electrostatic image is made visible by contacting the surface bearing said image with a developer comprising finely divided toner particles of thermoplastic resin binder containing coloring pigment, the improvement according to which toner filming of the image bearing surface is reduced by incorporating in the developer in an amount up to 10% by weight of the toner and in particle size smaller than the toner, a particulate pigment-free organic polymer additive selected from the group consisting of polytetrafluoroethylene, polyvinylfluoride, polyvinylidenefluoride, polyethylene, polyhexafluoropropylene, copolymers of tetrafluoroethylene with tetrafluoropropylene, and copolymers of tetrafluoroethylene with hexafluoropropylene.
Claim 2
Dependent Claim
99 words
In an electrophotographic process wherein an electrostatic image is made visible by contacting the surface bearing said image with a developer comprising finely divided toner particles of thermoplastic resin binder containing coloring pigment, the improvement according to which toner filming of the image bearing surface is reduced by incorporating in the developer in an amount up to 10% by weight of the toner and in particle size smaller than the toner, a particulate pigment-free organic polymer additive selected from the group consisting of polytetrafluoroethylene, polyvinylfluoride, polyvinylidenefluoride, polyethylene, polyhexafluoropropylene, copolymers of tetrafluoroethylene with tetrafluoropropylene, and copolymers of tetrafluoroethylene with hexafluoropropylene.
Claim 3
Dependent Claim
15 words
A process as claimed in claim 1 wherein the polymer additive is a tetrafluoroethylene-hexafluoropropylene copolymer.
Claim 4
Dependent Claim
13 words
A process as claimed in claim 1 wherein the polymer additive is polyethylene.
Claim 5
Dependent Claim
13 words
A process as claimed in claim 1 wherein the polymer additive is polyhexafluoropropylene.
Claim 6
Dependent Claim
13 words
A process as claimed in claim 1 wherein the polymer additive is polytetrafluoroethylene.
Claim 7
Dependent Claim
19 words
A process as claimed in claim 1 wherein the polymer additive particles have diameters of less than one micron.
Claim 8
Dependent Claim
22 words
A process as claimed in claim 1 wherein said toner and said polymer additive are freely movable in relation to each other.
Claim 9
Dependent Claim
13 words
A process as claimed in claim 1 wherein the polymer additive is polyvinylidenefluoride.
Claim 10
Dependent Claim
85 words
A dry developer composition for electrophotography comprising a toner of finely divided particles of resin and particles of an additive in an amount up to about 10% by weight of said toner, of a synthetic resin other than the resin of said toner, said particles of additive having an average size smaller than that of said toner particles, said particles of additive being at least one pigment-free synthetic resin selected from the group consisting of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl fluoride, polyethylene, polyhexafluoropropylene, poly(tetrafluoroethylene-tetrafluoropropylene) and poly(tetrafluoroethylene-hexafluoropropylene).
Claim 11
Dependent Claim
85 words
A dry developer composition for electrophotography comprising a toner of finely divided particles of resin and particles of an additive in an amount up to about 10% by weight of said toner, of a synthetic resin other than the resin of said toner, said particles of additive having an average size smaller than that of said toner particles, said particles of additive being at least one pigment-free synthetic resin selected from the group consisting of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl fluoride, polyethylene, polyhexafluoropropylene, poly(tetrafluoroethylene-tetrafluoropropylene) and poly(tetrafluoroethylene-hexafluoropropylene).
Claim 12
Dependent Claim
74 words
A dry developer composition for electrophotography comprising a toner of finely divided particles of thermoplastic resin and discrete particles of an additive, the additive being in an amount of up to 10% by weight of said toner and in particle size smaller than said toner, said additive being a pigment-free synthetic resin selected from the group consisting of polytetrafluoroethylene, polyvinylfluoride, polyvinylidenefluoride, polyethylene, polyhexafluoropropylene, copolymers of tetrafluoroethylene with tetrafluoropropylene, and copolymers of tetrafluoroethylene with hexafluoropropylene.
Claim 13
Dependent Claim
74 words
A dry developer composition for electrophotography comprising a toner of finely divided particles of thermoplastic resin and discrete particles of an additive, the additive being in an amount of up to 10% by weight of said toner and in particle size smaller than said toner, said additive being a pigment-free synthetic resin selected from the group consisting of polytetrafluoroethylene, polyvinylfluoride, polyvinylidenefluoride, polyethylene, polyhexafluoropropylene, copolymers of tetrafluoroethylene with tetrafluoropropylene, and copolymers of tetrafluoroethylene with hexafluoropropylene.
Claim 14
Dependent Claim
12 words
A composition as claimed in claim 10 wherein the additive is polytetrafluoroethylene.
Claim 15
Dependent Claim
12 words
The composition as claimed in claim 10 wherein the additive is polyvinylidenefluoride.
Claim 16
Dependent Claim
12 words
The composition as claimed in claim 10 wherein the additive is polyethylene.
Claim 17
Dependent Claim
12 words
A composition as claimed in claim 10 wherein the additive is polyhexafluoropropylene.
Claim 18
Dependent Claim
17 words
A composition as claimed in claim 10 wherein the additive is a copolymer of tetrafluoroethylene and hexafluoropropylene.
References Cited (Backward Citations)
US2611153A
Cited
US2638416A
Cited
US2618551A
Cited
US2940934A
Cited
US2788288A
Cited
US3030260A
Cited
US2985918A
Cited
US3280036A
Cited
US3079342A
Cited
US3153681A
Cited
US3262806A
Cited
US3392139A
Cited
US3349703A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-04 | 1983-08-06 | 1984-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-04 | 1987-08-06 | 1988-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-04 | 1991-08-06 | 1992-02-05 | $7700.00 | Window Closed / Lapsed |