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US 4,060,415 AGranted
Electrophotographic process
AssigneeOce-van der Grinten N.V.
InventorsPetrus J. M. van Nunen, Willem VAN Barneveld
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AssigneeOce-van der Grinten N.V.
InventorsPetrus J. M. van Nunen, Willem VAN Barneveld
Estimating the term…
Electrophotographic copies having images of high optical density formed on photoconductive layers having little weight and suitably transparent for use as photocopying originals are produced by charging electrostatically and exposing imagewise a photoconductive layer of less than 10 g/m.sup.2 in dry weight and less than 6 microns in thickness which contains zinc oxide and a binder in a weight proportion of between 9 and 14 and is chargeable at most to a surface potential of between 100 and 250 V, this layer being carried on a conductive flexible support having a specific resistance of less than 10.sup.13 ohm. cm, and thereafter developing the resulting charge pattern by contacting it during at most 3 seconds with a "one-component" powder which contains pigment dispersed in resin and has a specific resistance below 10.sup.7 ohm. cm, while maintaining a conductive connection between the developing powder and said support.
An electrophotographic process which comprises charging electrostatically and thereafter exposing imagewise a photoconductive layer of less than 6 microns in thickness containing zinc oxide and a binder in a weight ratio ZnO:binder of between 9 and 14 to 1 and which layer is chargeable at most to a surface potential between 100 and 250 V, said layer being present on a flexible support having a specific resistance of less than 10.sup.13 ohm. cm, and developing the charge pattern resulting on said layer so as to render it visible by contacting it during not more than 3 seconds with one-component developing powder of a mass thereof the particles of which are of substantially the same composition and predominantly comprise resin and finely divided relatively conductive material, and which has a specific resistance below 10.sup.7 ohm. cm, while maintaining a connection for charge conductance, at least in part through said mass, between said powder and said support.
An electrophotographic process which comprises charging electrostatically to a surface potential of between 100 and 200 V and thereafter exposing imagewise a photoconductive layer consisting essentially of zinc oxide and a binder in a weight ratio ZnO:binder of between 9 and 14 to 1, said layer being of less than 8 g/m.sup.2 in dry weight and less than 6 microns in thickness and being present on a flexible support that is transparent to actinic light and has a dry weight of 40 to 75 g/m.sup.2 and has a specific resistance of less than 10.sup.12 ohm. cm, and developing the resulting charge pattern so as to render it visible by contacting said layer with one-component developing powder of a mass thereof the particles of which are of substantially the same composition and of between 10 and 40 microns in size and predominantly comprise resin and finely divided relatively conductive material, and which has a specific resistance of between 10.sup.2 and 10.sup.5 ohm. cm, while maintaining a connection for charge conductance, at least in part through said mass, between said powder and said support.
An electrophotographic copy comprising a flexible support which is transparent to actinic light and has a dry weight of 40 to 75 g/m.sup.2 and a specific resistance of less than 10.sup.12 ohm. cm., on said support a photoconductive layer consisting essentially of zinc oxide and a binder in a weight ratio ZnO:binder of between 9 and 14 to 1 and which is chargeable at most to a surface potential between 100 and 200 V, said layer being of less than 8 g/m.sup.2 in dry weight and less than 6 microns in thickness, and on said layer an electrostatically formed image composed of a developing powder the particles of which are of substantially the same composition and of between 10 and 40 microns in size and predominantly comprise resin and finely divided relatively conductive material, and which has a specific resistance of between 10.sup.2 and 10.sup.5 ohm. cm.
Dependencies are inferred from the claim text.