Polyester toner microspheres for electrophotographic imaging systems
AssigneeHoechst Celanese Corporation
InventorsMarie Borzo, Kophu Chiang, Eui-Won Choe, Rao D. Mikkilineni, Hyun-Nam Yoon
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Abstract
This invention provides a free-flowing polyester dye microspheric powder which has superior stability and transparency for application in electrophotographic imaging systems. In another embodiment this invention provides a non-aqueous dispersion polymerization process for producing the invention polyester dye microspheric powder. A present invention toner composition comprises polyester dye microspheric powder, and one or more optional ingredients such as a charge control agent or a surfactant.
Claims32
A toner composition for electrophotographic imaging systems which comprises polyester dye microspheres having an average particle size between about 3-10 microns, and having between about 0.1-20 mole percent of recurring chromophoric diester monomer units, and having a weight average molecular weight between about 5000-100,000, and exhibiting a glass transition temperature (T.sub.g) between about 40.degree.-120.degree. C., and a melt-viscosity between about 200-5500 poises at 150.degree. C.
A process for producing a toner composition which comprises polyester dye microspheres having an average particle size between about 3-10 microns, and having between about 0.1-20 mole percent of recurring chromophoric diester monomer units, and having a weight average molecular weight between about 5000-100,000, and exhibiting a glass transition temperature (T.sub.g) between about 40.degree.-120.degree. C., and a melt-viscosity between about 200-5500 poises at 150.degree. C., which process comprises copolymerizing a dispersed insoluble phase of diol monomer and chromophoric diester monomer in a liquid organic medium in the presence of a nonionic surfactant at a temperature between about 100.degree.-280.degree. C. with high shear mixing, and separating the formed polyester dye microspheres from the liquid organic medium.
Dependencies are inferred from the claim text.