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US 3,959,574 AGranted
Biasable member and method for making
AssigneeXerox Corporation
InventorsDonald A. Seanor, James A. Lentz, Clifford O. Eddy, Stephen Strella
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AssigneeXerox Corporation
InventorsDonald A. Seanor, James A. Lentz, Clifford O. Eddy, Stephen Strella
Estimating the term…
Rolls, belts and other biasable members having controlled resistivity are described. The resistivity of the elastomeric resilient polyurethane coating on biasable members is controlled by ionic additives incorporated in the polyurethane. Biasable members having at least one layer or coating of a hydrophilic elastomeric polyurethane containing resistivity altering compounds or agents have substantially reduced resistivity changes with changes in relative humidity. The utility of such biasable members is in the transfer of xerographic images from a photoconductor to a final support sheet where the member, for example, a bias transfer roll, electrically cooperates with a photoconductor to establish a directional force field therebetween.
A member for electrically cooperating with a photoconductive surface to attract charged toner particles from the surface towards the member comprising a conductive substrate for supporting a uniform bias potential thereon and at least one coating comprising a resilient elastomeric polyurethane having an additive therein for controlling the resistivity of the elastomeric polyurethane, the coating being in contact with the conductive substrate, and having an electrical resistivity such that the coating is capable of transmitting a bias potential from the substrate to the outer periphery of the coating.
A method of controlling the resistivity of a member for electrically cooperating with a photoconductive surface to attract charged toner particles from the surface towards the member, comprising coating a conductive substrate for supporting a uniform bias potential thereon with at least one layer of a resilient elastomeric polyurethane having at least one additive incorporated therein to alter the resistivity of the elastomeric polyurethane, whereby the elastomeric polyurethane having an altered resistivity is capable of transmitting a bias potential from the substrate to the outer periphery thereof.
A roll for electrically cooperating with a photoconductive plate when brought into contact therewith to attract charged toner particles from the plate toward the roll comprising a rigid cylindrical core of electrically conductive material having at least one coating of a resilient elastomeric polyurethane having an additive therein to control the resistivity of the elastomeric polyurethane, and having an electrical resistivity such that the coating is capable of transmitting a bias potential from the core of electrically conductive material to the outer periphery of the coating.
A method of preventing changes in the resistivity of members for electrically cooperating with a photoconductive surface to attract charged toner particles from the surface towards the members caused by changes in relative humidity comprising adding a quaternary ammonium compound to a resilient hydrophilic elastomeric polyurethane and applying at least one coating of said polyurethane to a cylindrical core of electrically conductive material for electrically cooperating with the photoconductive surface when brought into contact therewith, whereby the elastomer is capable of transmitting a bias potential from the core of electrically conductive material to the outer periphery thereof and significant reductions in the sensitivity of the resistivity to changes in relative humidity occur.
Dependencies are inferred from the claim text.