Inductive development materials for a magnetic development process

Claim 1

A magnetic brush inductive development process comprising the steps of providing an electrostatographic imaging member having a recording surface, forming an electrostatic latent image on said recording surface, and contacting the recording surface with an electrostatographic developer mixture comprising electrically conductive carrier particles and a finely-divided toner composition, said toner composition comprising a colorant, a thermoplastic resin, a magnetic or magnetically attractable material, present in an amount of form about 10% to about 80% by weight, and being selected from the group consisting of magnetite, ferrites, iron, and nickel, and a triboelectric charging-enhancing material dispersed in the toner composition, present in an amount of between about 0.25% to about 15% by weight, and selected from the group consisting of alkyl pyridinium compounds, long chain hydrazinium compounds, quaternary ammonium compounds, and fluorosurfactants comprising ionic solubilizing groups linked to highly branched perfluoro groups, said toner composition being characterized as possessing triboelectric charging properties such that it is charged to a level of from about 15 microcoulombs per gram to about 30 microcoulombs per gram of toner composition, a resistivity of at least 10 14 ohm-cm, and promotes homogeneous mixing of said toner composition with said carrier particles thereby improving transport of the toner particles and avoiding clumping of the toner particles, whereby at least a portion of said finely-divided toner composition is attracted to and deposited on said recording surface in conformance with said electrostatic image.