Dry electrostatographic developer composition
AssigneeAgfa-Gevaert
InventorsSerge M. Tavernier, Paul F. Sterckx, Jean-Marie O. Dewanckele
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Abstract
A negatively-chargeable dry electrostatographic developer is disclosed containing fluorinated inorganic microparticles, and toner particles comprising an acidic binder resin having an acid value between 10 and 30 mg KOH/G and not comprising (a) charge-controlling agent(s). The developers according to this invention show excellent fluidity and have improved negative chargeability. According to a preferred mode, fluorinated silica-type microparticles are added to the developer as free flowing additive in an amount of 0.1 to 5% by weight with respect to the toner, which preferably comprises an acidic carbon black.
Claims14
Dry electrostatographic developer suitable for use in the development of an electrostatic charge pattern, comprising inorganic microparticles containing fluor containing groups in an amount sufficient to enhance the flowability and negative chargeability of the developer particles and negatively chargeable toner particles comprising an acidic binder resin having an acid value between 10 and 30 mg KOH/g and not comprising (a) charge controlling agent(s) and featuring a classified size distribution wherein more than 90 percent by volume of the toner particles have equivalent particle size diameters between 1 and 7 micron.
Dependencies are inferred from the claim text.