Patent US3922381A successfully refreshed from Google Patents.
US3922381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemically treated carrier particles for use in electrophotographic process
Assignee: AB Dick Co
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Filing: 1974-06-14
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Granted: 1975-11-25
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Expires: 1994-06-14
Abstract
Abstract Carrier particles for use in an electrophotographic process are prepared by applying a perfluoro acid to the surface of the carrier particle. The resulting carriers are long lived and capable of imparting a positive triboelectric charge to electroscopic powders mixed therewith.
Inventors
- 👤 Pabitra Datta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:17
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1138
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
70 words
A CARRIER FOR USE IN ELECTROPHOTOGRAPHIC DEVELOPMENT OF LATENT ELECTROSTATIC IMAGES CAPABLE OF INDUCING AN ELECTROSTATIC CHARGE IN A TONER MIXED THEREWITH WHICH COMPRISES A MEMBER SELECTED FROM THE GROUP CONSISTING OF METALLIC PARTICLES AND SILICEOUS PARTICLES TO THE SURFACE OF WHICH IS ADHERED A MEMBER SELECTED FROM THE GROUP CONSISTING OF PERFLUORINATED AND SUBSTANTIALLY PERFLUORINATED CARBOXYLIC ACIDS CONTAINING FROM 3 TO 18 CARBON ATOMS AND ESTERS AND AMIDES THEREOF.
Claim 2
Dependent Claim
70 words
A CARRIER FOR USE IN ELECTROPHOTOGRAPHIC DEVELOPMENT OF LATENT ELECTROSTATIC IMAGES CAPABLE OF INDUCING AN ELECTROSTATIC CHARGE IN A TONER MIXED THEREWITH WHICH COMPRISES A MEMBER SELECTED FROM THE GROUP CONSISTING OF METALLIC PARTICLES AND SILICEOUS PARTICLES TO THE SURFACE OF WHICH IS ADHERED A MEMBER SELECTED FROM THE GROUP CONSISTING OF PERFLUORINATED AND SUBSTANTIALLY PERFLUORINATED CARBOXYLIC ACIDS CONTAINING FROM 3 TO 18 CARBON ATOMS AND ESTERS AND AMIDES THEREOF.
Claim 3
Dependent Claim
29 words
A composition according to claim 1 wherein the carrier comprises a monomolecular layer of Said acid, ester or amide adhered to the surface of said particles by chemical adsorption.
Claim 4
Dependent Claim
12 words
A composition according to claim 1 wherein said acid is perfluorooctanoic acid.
Claim 5
Dependent Claim
12 words
A composition according to claim 1 wherein said acid is perfluoropropionic acid.
Claim 6
Dependent Claim
12 words
A composition according to claim 1 wherein said acid is perfluorobutyric acid.
Claim 7
Dependent Claim
12 words
A composition according to claim 1 wherein said acid is perfluorodecanoic acid.
Claim 8
Dependent Claim
15 words
A composition according to claim 1 wherein said acid is 11 -H - eicosafluoroundecanoic acid.
Claim 9
Dependent Claim
12 words
A composition according to claim 1 wherein said acid is perfluoroglutaric acid.
Claim 10
Dependent Claim
11 words
A composition according to claim 1 wherein said amide is perfluoroacetamide.
Claim 11
Dependent Claim
15 words
A composition according to claim 1 wherein said electrostatic charge is of a positive polarity.
Claim 12
Dependent Claim
11 words
A composition according to claim 1 wherein said particles are magnetic.
Claim 13
Dependent Claim
11 words
A composition according to claim 1 wherein said particles are non-magnetic.
Claim 14
Dependent Claim
11 words
A composition according to claim 1 wherein said particles are iron.
Claim 15
Dependent Claim
13 words
A composition according to claim 1 wherein said particles are spherical iron beads.
Claim 16
Dependent Claim
12 words
A composition according to claim 1 wherein said particles are phosphated iron.
Claim 17
Dependent Claim
98 words
A process for developing a latent electrostatic image which comprises mixing an electroscopic powder with a carrier comprising a member selected from the group consisting of metallic particles and siliceous particles to the surface of which is adhered a member selected from the group consisting of perfluorinated and substantially perfluorinated carboxylic acids containing from 3 to 18 carbon atoms and esters and amides thereof to impart opposite electrostatic charges to said electroscopic powder and said carrier, whereby said electroscopic powder is attracted to said carrier and transferring said electroscopic powder from said carrier to said latent electrostatic image.
Claim 18
Dependent Claim
98 words
A process for developing a latent electrostatic image which comprises mixing an electroscopic powder with a carrier comprising a member selected from the group consisting of metallic particles and siliceous particles to the surface of which is adhered a member selected from the group consisting of perfluorinated and substantially perfluorinated carboxylic acids containing from 3 to 18 carbon atoms and esters and amides thereof to impart opposite electrostatic charges to said electroscopic powder and said carrier, whereby said electroscopic powder is attracted to said carrier and transferring said electroscopic powder from said carrier to said latent electrostatic image.
Claim 19
Dependent Claim
17 words
A process according to claim 16 wherein said transferring step is accomplished by means of cascade development.
Claim 20
Dependent Claim
18 words
A process according to claim 16 wherein said transferring step is accomplished by means of magnetic brush development.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |