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US4373016A
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Process of transferring monocomponent developing powder with a volatile, dielectric liquid
Assignee: Rhone Poulenc Systemes SA
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Filing: 1981-05-12
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Granted: 1983-02-08
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Expires: 2001-05-12
Abstract
Abstract This invention provides a process of electrographic reproduction onto an arbitary support, whereby an image of a magnetic, monocomponent developing powder is transferred, under the influence of electrical means, onto a support covered with a thin layer of volatile dielectric liquid having a volume resistivity greater than 103 ohm-cm2/cm.
Inventors
- 👤 Donald H. M. Kings
- 👤 Jean-Claude Marckmann
- 👤 Pham K. Quang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:19
CPC Classifications
G; G03; G03G; G03G13/00; G03G13/14; G03G13/16
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
102 words
A process of electrographic reproduction comprising the steps of: (a) Forming an image of electrostatic charges on a temporary support, (b) Developing the image with a dry, conductive monocomponent developing powder in which a charge of either polarity is induced by the image of electrostatic charges to form a powder image, and (c) Transferring the powder image to an arbitrary support having deposited thereon a volatile dielectric liquid having a volume resistivity of greater than 10 3 Ωcm 2 /cm, said volatile dielectric liquid not capable of readily dissolving the resins in the developing powder, the arbitrary support or the temporary support.
Claim 2
Dependent Claim
102 words
A process of electrographic reproduction comprising the steps of: (a) Forming an image of electrostatic charges on a temporary support, (b) Developing the image with a dry, conductive monocomponent developing powder in which a charge of either polarity is induced by the image of electrostatic charges to form a powder image, and (c) Transferring the powder image to an arbitrary support having deposited thereon a volatile dielectric liquid having a volume resistivity of greater than 10 3 Ωcm 2 /cm, said volatile dielectric liquid not capable of readily dissolving the resins in the developing powder, the arbitrary support or the temporary support.
Claim 3
Dependent Claim
16 words
A process according to claim 1 wherein the powder image is fixed on the arbitrary support.
Claim 4
Dependent Claim
24 words
A process according to claim 1 or 2 wherein the powder image is transferred onto an arbitrary support which is a rigid metallic roller.
Claim 5
Dependent Claim
31 words
A process according to claim 3 wherein the powder image which has been first transferred onto the metallic roller is simultaneously transferred and fixed onto a copy support by cold pressure.
Claim 6
Dependent Claim
31 words
A process according to claim 4 wherein the powder image which has been first transferred onto the metallic roller is simultaneously transferred and fixed onto a copy support by cold pressure.
Claim 7
Dependent Claim
24 words
A process according to claim 4 wherein the volatile dielectric liquid is evaporated from the metallic roller prior to transferring onto the copy support.
Claim 8
Dependent Claim
27 words
A process according to claim 1 wherein the quantity of the volatile dielectric liquid applied to the arbitrary support is between 0.01 and 16 g/m 2 .
Claim 9
Dependent Claim
27 words
A process according to claim 7 wherein the quantity of the volatile dielectric liquid applied to the arbitrary support is between 2 and 5 g/m 2 .
Claim 10
Dependent Claim
27 words
A process according to claim 1 wherein the volatile dielectric liquid has a volume resistivity of from about 10 3 to about 10 15 Ωcm 2 /cm.
Claim 11
Dependent Claim
20 words
A process according to claim 1 wherein the volatile dielectric liquid has a volatility index of from 0.01 to 0.4.
Claim 12
Dependent Claim
21 words
A process according to claim 1 wherein the volatile dielectric liquid has a boiling point between 60° C. and 230° C.
Claim 13
Dependent Claim
35 words
A process according to claim 1 wherein the volatile dielectric liquid is selected from the group consisting of straight chain aliphatic hydrocarbons, branched chain aliphatic hydrocarbons, saturated cyclic aliphatic hydrocarbons, polyisobutenes, polyfluoroethylenes and mixtures thereof.
Claim 14
Dependent Claim
59 words
A process according to claim 1 wherein the developing powder has a volumetric resistivity of from 10 7 to 10 15 Ωcm 2 /cm, the volumetric resistivity being measured in a cell of cross section 0.07 cm 2 on a sample 2 mm deep under a pressure of 750 g/cm 2 and a continuous electric field of 1000 v/cm.
Claim 15
Dependent Claim
22 words
A process according to claim 1 including the additional step of subjecting the powder image to illumination prior to the transfer step.
Claim 16
Dependent Claim
26 words
A process according to claim 1 wherein the transfer step (c) is conducted using an electric field existing between the temporary support and the arbitrary support.
Claim 17
Dependent Claim
18 words
A process according to claim 1 wherein the transfer step (c) is conducted using a corona effect device.
Claim 18
Dependent Claim
12 words
A process according to claim 1 wherein the developing powder is magnetic.
Claim 19
Dependent Claim
31 words
A process according to claim 1 wherein the powder image is subjected to controlled illumination in order to obtain a partial discharge of the temporary support prior to the transfer step.
Claim 20
Dependent Claim
24 words
A process according to claim 13 wherein the developing powder has a volumetric resistivity of from 10 8 to 10 13 ohm-cm 2 /cm.
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) | 1986-02-07 | 1986-08-09 | 1987-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-07 | 1990-08-09 | 1991-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-07 | 1994-08-09 | 1995-02-08 | $7700.00 | Window Closed / Lapsed |