US4068017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coated carrier particles for use in electrophotographic process
Assignee: AB Dick Co
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Filing: 1976-07-30
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Granted: 1978-01-10
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Expires: 1996-07-30
Abstract
Abstract Carrier particles for use in an electrophotographic process are prepared by applying a mixture of a perfluoro acid and polyvinylidene fluoride to the surface of the carrier particle. The resulting carriers are long lived, abrasion resistant and capable of imparting a high triboelectric charge to electroscopic powders mixed therewith.
Inventors
- 👤 Virgil William Westdale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:05
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1132; G03G9/1133; G03G9/1134; G03G9/1138; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993; Y10T428/2996; Y10T428/2998; Y10T428/31504; Y10T428/3154
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
93 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 mixture of polyvinylidene fluoride and 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, said polyvinylidene fluoride and acid being present in a ratio by weight of about 0.2:1 to 8:1.
Claim 2
Dependent Claim
93 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 mixture of polyvinylidene fluoride and 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, said polyvinylidene fluoride and acid being present in a ratio by weight of about 0.2:1 to 8:1.
Claim 3
Dependent Claim
24 words
A composition according to claim 1 wherein said polyvinylidene fluoride and acid are present in a ratio by weight of about 2:1 to 3:1.
Claim 4
Dependent Claim
12 words
A composition according to claim 1 wherein said acid is perfluorooctanoic acid.
Claim 5
Dependent Claim
14 words
A composition according to claim 1 wherein said electrostatic charge is of positive polarity.
Claim 6
Dependent Claim
11 words
A composition according to claim 1 wherein said particles are non-magnetic.
Claim 7
Dependent Claim
11 words
A composition according to claim 1 wherein said particles are magnetic.
Claim 8
Dependent Claim
11 words
A composition according to claim 1 wherein said particles are iron.
Claim 9
Dependent Claim
55 words
A process for developing a latent electrostatic image which comprises mixing an electroscopic powder with a carrier according to claim 1 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 10
Dependent Claim
17 words
A process according to claim 8 wherein said transferring step is accomplished by means of cascade development.
Claim 11
Dependent Claim
18 words
A process according to claim 8 wherein said transferring step is accomplished by means of magnetic brush development.
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) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |