US4252882A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developing electrophotographic images using aqueous ink and treating smooth, hydrophobic image surface with cleaning liquid
Assignee: Hoechst AG
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Filing: 1977-10-21
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Granted: 1981-02-24
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Expires: 1997-10-21
Abstract
Abstract This invention relates to an improvement in a copying process wherein a latent image produced on a chargeable imaging surface by electrostatic charging and exposure is developed by means of an aqueous ink and transferred onto a receiving material and the imaging surface is then cleaned, the improvement being that the imaging surface has a completely smooth, hydrophobic surface which preferably is not wetted by the aqueous ink applied by means of a known structured applicator element, and the cleaning liquid used to detach residual ink still present after transfer can be easily wiped off and forms a wetting angle of more than 90° with the imaging surface. The invention also relates to the developer liquid and the cleaning liquid used in the process.
Inventors
- 👤 Heinz Herrmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:40
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/06; G03G13/10; G03G21/00; G03G21/0088; G03G5/00; G03G5/005; G03G9/00; G03G9/16; G03G9/18
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
136 words
In a copying process wherein a latent image produced by electrostatic charging and exposure on a chargeable imaging surface containing at least one organic photoconductor is developed by means of an aqueous ink and transferred onto a receiving material and the imaging surface is then cleaned, the improvement comprising that (a) said imaging surface has a completely smooth, hydrophobic surface to which the aqueous ink is applied by means of a known structured applicator element, (b) said aqueous ink applied to said imaging surface does not wet said surface and (c) using a cleaning liquid to detach residual ink still present after transfer, said cleaning liquid being easily wiped off by a simple, sharp-edged doctor blade or by use of an air brush and forming a wetting angle of more than 90° with said imaging surface.
Claim 2
Dependent Claim
136 words
In a copying process wherein a latent image produced by electrostatic charging and exposure on a chargeable imaging surface containing at least one organic photoconductor is developed by means of an aqueous ink and transferred onto a receiving material and the imaging surface is then cleaned, the improvement comprising that (a) said imaging surface has a completely smooth, hydrophobic surface to which the aqueous ink is applied by means of a known structured applicator element, (b) said aqueous ink applied to said imaging surface does not wet said surface and (c) using a cleaning liquid to detach residual ink still present after transfer, said cleaning liquid being easily wiped off by a simple, sharp-edged doctor blade or by use of an air brush and forming a wetting angle of more than 90° with said imaging surface.
Claim 3
Dependent Claim
16 words
A process according to claim 1 in which the imaging surface contains polyvinyl carbazole and trinitrofluorenone.
Claim 4
Dependent Claim
19 words
A process according to claim 1 in which the imaging surface contains a condensation product of 3-bromopyrene and formaldehyde.
Claim 5
Dependent Claim
27 words
A process according to claim 1 in which the imaging surface is a photoconductive double layer composed of a charge carrier-producing layer and a charge carrier-transporting layer.
Claim 6
Dependent Claim
22 words
A process according to claim 1 in which the imaging surface is an organic photoconductor layer covered by a hydrophobic protective layer.
Claim 7
Dependent Claim
14 words
A process according to claim 1 in which the chargeable imaging surface is flexible.
Claim 8
Dependent Claim
20 words
A process according to claim 1 in which the aqueous ink is an aqueous solution of at least one dye.
Claim 9
Dependent Claim
18 words
A process according to claim 1 in which the aqueous ink is an aqueous dispersion of a pigment.
Claim 10
Dependent Claim
18 words
A process according to claim 8, in which the aqueous pigment dispersion contains at least one water-soluble dye.
Claim 11
Dependent Claim
18 words
A process according to claim 1 in which the aqueous ink is readily detached by the cleaning liquid.
Claim 12
Dependent Claim
19 words
A process according to claim 9 in which the aqueous ink is a solution of Paper Deep Black AGX.
Claim 13
Dependent Claim
18 words
A process according to claim 1 including adjusting the viscosity of the aqueous ink by changing its concentration.
Claim 14
Dependent Claim
17 words
A process according to claim 1 including adapting the viscosity to the applicator by adding a thickener.
Claim 15
Dependent Claim
14 words
A process according to claim 1 in which the cleaning liquid is desalted water.
Claim 16
Dependent Claim
18 words
A process according to claim 1 in which the cleaning liquid is desalted water and a weak base.
Claim 17
Dependent Claim
26 words
A process according to claim 1 in which the cleaning liquid used additionally contains an organic liquid by which its surface tension is only slightly reduced.
Claim 18
Dependent Claim
13 words
A process according to claim 16 in which the organic liquid is formamide.
Claim 19
Dependent Claim
24 words
A process according to claim 1 in which the cleaning liquid is a non-wetting liquid ink which is also used as the aqueous ink.
Claim 20
Dependent Claim
15 words
A process according to claim 18 including an anti-foaming agent added to the aqueous ink.
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) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |