Electrographic developer compositions and methods

摘要

Disclosed are developer compositions for use in an electrographic development process and methods for using such compositions. The developer includes a hard magnetic material as a carrier, and also a toner material which comprises a polymeric resin, colorant, and a hydrophobic silica or hydrophilic silica, in an amount sufficient to reduce the dusting of toner particles off of the carrier particles during use, as well as to maintain the charge to mass ratio of the toner during use so as to increase the useful life of the developer composition. Also disclosed are methods of using such developer compositions.