Electrostatographic carrier coated with thixotropic compositions
AssigneeXerox Corporation
InventorsSteven B. Bolte, Richard B. Lewis
Life of this patent
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Abstract
Electrostatographic carrier coating compositions which provide porous carrier cores with coatings that are more uniform in thickness and complete in integrity are obtained by employing a thixotropic lacquer. The nature of the thixotropic lacquer is such that its viscosity is low under high shear rates, but high under low shear rates as found during the spreading and penetration of the lacquer on the carrier cores.
Claims4
An improved process for preparing coated electrostatographic carrier particles, for use in developing compositions employed in the development of electrostatic latent images in an electrophotographic imaging device, comprising coating carrier core particles selected from the group consisting of iron, steel, ferrite, magnetite, nickel, and mixtures thereof, which particles have an average diameter of between about 30 microns and about 1,000 microns, by spray drying onto said particles a thixotropic coating lacquer comprised of fumed silica particles, in an amount of from about 0.05 percent to about 3.0 percent by weight based on the weight of the coated carrier particles, whereby the properties of the fumed silica particles cause a reduction in the penetration of such particles into the pores of the carrier core particles, thereby producing particles of a stable triboelectric charge.
Dependencies are inferred from the claim text.