Patent ID: 6294303
Filing Date: 2001-09-25
Classification: G03G

Abstract:
In a monocomponent electrostatographic developer comprising negatively charging toner particles comprising a polymeric binder and magnetic material and wherein the toner particle surface contains particles of positively chargeable inorganic fine powder particles, the improvement wherein:said inorganic fine powder particles have a mean volume average particle size of about 0.5 to 7 .mu.m, and a cleaning ratio of between about 0.76 to 4.0;said cleaning ratio being the volume fraction of particles between 0 and 1.0 .mu.m, divided by the volume fraction of particles greater than 1.0 .mu.m; andthe toner particles have on the surface thereof a flowability improving agent having a BET surface area of at least 30 m.sup.2 /g.