Toner Charge Polarity Reversal Phenomena In Two-component Developer

Abstract

The role of carbon black and CCA in triboelectrification was elucidated by studies on the mechanism of charge polarity inversion during agitation of model toners with silicone-coated ferrite carrier. Carbon black itself has very low tribocharging ability. The role of carbon black seems to be to decrease the number of charging sites on the surface of the toner particle. CCA itself has very high tribocharging ability. The role of CCA seems to be that the charge of the toner particle is either increased or decreased from the toner composed only of the resin even if the presence of CCA on the surface of the toner particle decreases the number of charging sites composed of the resin. It is proposed that triboelectrification of two-component developers can be estimated by the concept of the time and energy dependent charging of positive and negative sites that arise on each component (binder resin, carbon black and CCA) of the toner surface.