US4055684A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coated carrier particles for use in electrophotographic process
Assignee: AB Dick Co
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Filing: 1976-05-03
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Granted: 1977-10-25
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Expires: 1996-05-03
Abstract
Abstract Carrier particles for use in an electrophotographic process are prepared by coating a particulate matrix with an ion exchange resin dispersed in a polymeric binder. The resulting coated carrier particles are long lived and depending upon the choice of ion exchange resin can be used to impart a positive or negative triboelectric charge of the magnitude desired to electroscopic powders mixed therewith.
Inventors
- 👤 Evan Serge Baltazzi
- 👤 Pabitra Datta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:11
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/08; G03G13/09; G03G9/00; G03G9/08; G03G9/10; G03G9/113; G03G9/1132; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
115 words
A process for developing a visual image from a latent electrostatic image which comprises applying to the surface upon which is formed the latent electrostatic image a developer mix comprising a finely divided electroscopic powder and discrete solid carrier particles selected from the group consisting of glass beads, ceramic beads, grains of sand and metallic particles, coated with a dispersion in a low surface energy thermoplastic polymeric binder of dried, finely ground particles in the micron to submicron range of a polymer consisting essentially of a backbone of a highly crosslinked copolymer of styrene and divinylbenzene having ion exchanging groups chemically bonded thereto; said coating being about from 1 micron to 3 microns in thickness.
Claim 2
Dependent Claim
115 words
A process for developing a visual image from a latent electrostatic image which comprises applying to the surface upon which is formed the latent electrostatic image a developer mix comprising a finely divided electroscopic powder and discrete solid carrier particles selected from the group consisting of glass beads, ceramic beads, grains of sand and metallic particles, coated with a dispersion in a low surface energy thermoplastic polymeric binder of dried, finely ground particles in the micron to submicron range of a polymer consisting essentially of a backbone of a highly crosslinked copolymer of styrene and divinylbenzene having ion exchanging groups chemically bonded thereto; said coating being about from 1 micron to 3 microns in thickness.
Claim 3
Dependent Claim
19 words
A process according to claim 1 wherein a positive electrostatic charge is imparted to particles of said electroscopic powder.
Claim 4
Dependent Claim
19 words
A process according to claim 1 wherein a negative electrostatic charge is imparted to particles of said electroscopic powder.
Claim 5
Dependent Claim
47 words
A process according to claim 1 wherein the electroscopic powder is applied to the surface carrying the latent electrostatic image by means of a magnetic brush and a positive electrostatic charge is induced in the particles of the electroscopic powder upon their separation from said carrier particles.
Claim 6
Dependent Claim
47 words
A process according to claim 1 wherein the electroscopic powder is applied to the surface carrying the latent electrostatic image by means of a magnetic brush and a negative electrostatic charge is induced in the particles of the electroscopic powder upon their separation from said carrier particles.
Claim 7
Dependent Claim
19 words
A process according to claim 1 wherein the development of the latent electrostatic image is a direct development process.
Claim 8
Dependent Claim
19 words
A process according to claim 1 wherein the development of the latent electrostatic image is a reversal development process.
Claim 9
Dependent Claim
15 words
A process according to claim 1 wherein the ion exchanging groups are cation exchanging groups.
Claim 10
Dependent Claim
15 words
A process according to claim 1 wherein the ion exchanging groups are anion exchanging groups.
Claim 11
Dependent Claim
30 words
A process according to claim 1 wherein said ion exchanging groups are selected from the group consisting of carboxylic acid groups, sulfonic acid groups, quaternary ammonium groups and amino groups.
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) | 1980-10-24 | 1981-04-25 | 1981-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-24 | 1985-04-25 | 1985-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-24 | 1989-04-25 | 1989-10-25 | $7700.00 | Window Closed / Lapsed |