Xerox Corporation

Christopher J AuClair

Chin H Lu

Meurig W Williams

Eugene Frederick Young

Peter F Erhardt

Steven R Perez

Alan R Monahan

This invention is directed to a negatively charged toner compositions comprised of resin particles and pigment particles, and from about 0.1 percent by weight to about 20 percent by weight, of an aryl sulfone, or aryl alkyl sulfonamide negative charge enhancing additive of the following formulas.

Toner compositions containing negative charge enhancing additives

This invention is generally directed to dry negatively charged toner compositions comprised of resin particles, pigment particles and a polyanhydride charge enhancing composition of the formula: ##STR1## wherein R is an alkyl group containing from about 6 carbon atoms to about 22 carbon atoms, and n is a number ranging from about 5 to about 2,000.

Toner compositions containing polyanhydride resins

Electrostatographic developer mixtures comprising finely-divided toner particles electrostatically clinging to the surface of carrier particles comprising a core having an outer coating thereon comprising a polyblend of a first polymer possessing negative triboelectric charging characteristics with respect to toner particles and a second polymer which possesses strong adhesive properties with respect to said core. The coated carrier particles have negative triboelectric charging properties and are particularly useful in development of negatively charged photoreceptors. Imaging processes are also disclosed.

Polyblend coated carrier materials

An electrostatographic developer mixture comprising finely-divided positively charging toner particles electrostatically clinging to negatively charging carrier particles. The toner particles comprise a resin, a colorant, and a charge inducing material selected from (1) a long chain hydrazinium compound and (2) an alkyl pyridinium compound. The carrier particles comprise core particles having a coating of fused thermoplastic resin particles wherein the carrier particles are prepared by dry-mixing the core particles with thermoplastic resin particles until the resin particles adhere to the core particles. The mixture of core and resin particles are heated to between 320.degree. F. and 650.degree. F. for between 20 and 120 minutes so that the resin particles melt and fuse to the core particles. The developer mixture is employed to develop electrostatic latent images.

Imaging system

A finely-divided toner composition comprising a thermoplastic vinyl resin and a surface active additive selected from the group consisting of fluorinated surfactants. The toner composition possesses controlled triboelectric charging properties while its other bulk properties remain unaffected. Developer compositions and electrostatographic imaging processes are also disclosed.

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Rochester, NY, United States of America

Christopher J AuClair