US4254196A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing lithoplates and plate
Assignee: CNA Holdings LLC
•
Filing: 1979-10-18
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Granted: 1981-03-03
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Expires: 1999-10-18
Abstract
Abstract A process for preparing a lithoplate by electrophotographic means is provided wherein the toned image is fused, the photoconductive layer in the nonimage area is decoated, and finally, the fused toner is selectively removed leaving oleophilic photoconductive material as the image portion.
Inventors
- 👤 Douglas A. Seeley
- 👤 Victor M. Kamhi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:46
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/26; G03G13/28
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
26 words
A press-ready electrophotographic lithographic printing plate comprising a support with a toner-free thin layer comprising a monomeric organic photoconductive insulating material adherent thereupon in imagewise configuration.
Claim 2
Dependent Claim
26 words
A press-ready electrophotographic lithographic printing plate comprising a support with a toner-free thin layer comprising a monomeric organic photoconductive insulating material adherent thereupon in imagewise configuration.
Claim 3
Dependent Claim
17 words
A press-ready electrophotographic printing plate according to claim 1 in which said image contains a 4,5 diphenyloxazole.
Claim 4
Dependent Claim
41 words
A press-ready electrophotographic lithographic printing plate according to claim 1 in which said support is selected from the group consisting of aluminum, zinc, magnesium, copper, specially treated papers, cellulose hydrate, fibers of cellulose acetate, cellulose butyrate, polyamides and metal vaporized films.
Claim 5
Dependent Claim
16 words
A press-ready electrophotographic lithographic printing plate according to claim 2 in which said support is aluminum.
Claim 6
Dependent Claim
128 words
A process for preparing a printing plate which comprises providing a thin coherent organic photoconductive insulating coating adherent on a conductive base material, and a. electostatically charging said photoconductive insulating layer, b. imagewise exposing said charged insulating layer to leak away the charge on the areas struck by light, c. developing the remaining charged areas with electroscopic material, d. fixing the image of electroscopic material thus obtained, e. removing said photoconductive coating in the nonimage areas only by contact with a first selective solvent which does not dissolve or attack the fixed electroscopic material, f. removing the electroscopic material present in imagewise configuration by contact with a second selective solvent incapable of dissolving or attacking said insulating material so that said insulating material is left in imagewise configuration.
Claim 7
Dependent Claim
128 words
A process for preparing a printing plate which comprises providing a thin coherent organic photoconductive insulating coating adherent on a conductive base material, and a. electostatically charging said photoconductive insulating layer, b. imagewise exposing said charged insulating layer to leak away the charge on the areas struck by light, c. developing the remaining charged areas with electroscopic material, d. fixing the image of electroscopic material thus obtained, e. removing said photoconductive coating in the nonimage areas only by contact with a first selective solvent which does not dissolve or attack the fixed electroscopic material, f. removing the electroscopic material present in imagewise configuration by contact with a second selective solvent incapable of dissolving or attacking said insulating material so that said insulating material is left in imagewise configuration.
Claim 8
Dependent Claim
15 words
A process acc. claim 5 in which said photoconductive insulating layer contains a 4,5 diphenyloxazole.
Claim 9
Dependent Claim
42 words
A process according to claim 6 in which said second selective solvent is selected from the group consisting of m,p-diethylbenzene, mesitylene, chlorinated hydrocarbons, methylcyclohexane and commercial mixtures of hydrocarbons approximately, by weight 29%-95% aromatic, 0%-28% naphthenic, 5%-43% paraffinic and mixtures of these.
Claim 10
Dependent Claim
23 words
A process according to claim 6 in which said second selective solvent is approximately by weight 29% aromatic, 28% naphthenic, and 43% aliphatic.
References Cited (Backward Citations)
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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) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |