A Nodal Model for Non-Linear Conduction in Toner Particles Modified with Conductive Additives

Abstract

Conductive toners utilized in some single- and dualcomponent development systems can be formulated by dispersing fine conductive additives on the surface of insulative toner particles. Electrical conductivity of such toners depends not only on intrinsic conductivity of the additives, but also on their dispersion on toner surface, and, to a great extent, on the method of conductivity measurement.The present model describes electrical conductance of an individual toner particle with a sub-monolayer of fine conductive additives dispersed on its surface. The model is based on an equivalent electrical circuit consisting of nodes assigned to individual additives, and non-linear resistors representing percolation currents between the additives. Non-linear current-balance equations constructed for each node were solved numerically to obtain the overall current-voltage response of an individual toner particle as a function of the size, volume fraction, and level of dispersion of the conductive additives. Experimental verification of the present model and methods of toner conductivity measurements will also be discussed.