Imaging process employing treated carrier particles

Claim 2

AN ELECTROSTATOGRAPHIC IMAGING PROCESS COMPRISING THE STEPS OF FORMING AN ELECTROSTATIC LATENT IMAGE ON AN IMAGING SURFACE AND DEVELOPING SAID ELECTROSTATIC LATENT IMAGE BY CONTACTING SAID ELECTROSTATIC LATENT IMAGE WITH AN ELECTROSTATOGRAPHIC DEVELOPER MIXTURE COMPRISING FINELY DIVIDED TONER PARTICLES ELECTROSTATICALLY CLINGING TO THE SURFACE OF LARGER, DYE-TREATED CARRIER PARTICLES, SAID CARRIER PARTICLES COMPRISING SOLID METALLIC PARTICLES SELECTED FROM THE GROUP CONSISTING OF METALS, METAL ALLOYS, METAL COMPOUNDS, AND MIXTURES THEREOF COATED WITH AN ADSORBED LAYER OF AN ORGANIC DYE WHEREIN SAID DYE-TREATED CARRIER PARTICLES ARE CHARACTERIZED AS BEING RESISTANT TO FLUCTUATIONS IN TRIBOELECTRIC PROPERTIES, WHEREBY AT LEAST A PORTION OF SAID FINELY DIVIDED TONER PARTICLES ARE ATTRACTED TO AND HELD ON SAID IMAGING SUFACE IN CONFORMANCE TO SAID ELECTROSTATIC LATENT IMAGE.

Claim 3

An electrostatographic imaging process comprising the steps of forming an electrostatic latent image on an imaging surface and developing said electrostatic latent image by contacting said electrostatic latent image with an electrostatographic developer mixture comprising finely divided toner particles electrostatically clinging to the surface of dye-treated carrier particles, said dye-treated carrier particles comprising metallic carrier particles coated with an adsorbed layer of an organic dye and wherein said dye-treated carrier particles are characterized as being resistant to fluctuations in triboelectric properties, said carrier particles having an average particle diameter from between about 1 micron and about 1,000 microns and having been selected from the group consisting of metals, metal alloys, metal compounds, and mixtures thereof, said dye having been selected in accordance with its triboelectric properties with respect to said toner particles so that when said toner particles are mixed or brought into contact with said treated carrier particles either said treated carrier particles or said toner particles are charged positively if said toner particles are below said treated carrier particles in a triboelectric series and negatively if said toner particles are above said treated carrier particles in said triboelectric series, whereby at least a portion of said finely divided toner particles are attracted to and held on said imaging surface in conformance to said electrostatic latent image.

Claim 4

An electrostatographic imaging process comprising the steps of forming an electrostatic latent image on an imaging surface and developing said electrostatic latent image by contacting said electrostatic latent image with an electrostatographic developer mixture comprising finely divided toner particles electrostatically clinging to the surface of dye-treated carrier particles, said dye-treated carrier particles comprising metallic carrier particles coated with an adsorbed layer of an organic dye and wherein said dye-treated carrier particles are characterized as being resistant to fluctuations in triboelectric properties, said carrier particles having an average particle diameter from between about 1 micron and about 1,000 microns and having been selected from the group consisting of metals, metal alloys, metal compounds, and mixtures thereof, said dye having been selected in accordance with its triboelectric properties with respect to said toner particles so that when said toner particles are mixed or brought into contact with said treated carrier particles either said treated carrier particles or said toner particles are charged positively if said toner particles are below said treated carrier particles in a triboelectric series and negatively if said toner particles are above said treated carrier particles in said triboelectric series, whereby at least a portion of said finely divided toner particles are attracted to and held on said imaging surface in conformance to said electrostatic latent image.

Claim 5

An electrostatographic imaging process according to claim 2 wherein said metallic carrier particles are selected from aluminum, cobalt, copper, iron, lead, magnesium, nickel, tin, zinc, gold, silver, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, zirconium, metal oxides, refractory nitrides, carbides, and mixtures thereof.

Claim 6

An electrostatographic imaging process according to claim 2 wherein said organic dye is selected from the group consisting of azo dyes, azoic dyes, azine dyes ketone dyes, phthalocyanine dyes, and mixtures thereof.

Claim 7

An electrostatographic imaging process according to claim 2 wherein said organic dye comprises Oil Red dye and said metallic carrier particles comprise iron filings.