ONE-COMPONENT DRY MAGNETIC TONER

摘要

PURPOSE:To prolong the service life of a toner and to reduce the cost by incorporating specified electrostatic charging agents into the toner particles. CONSTITUTION:Humic acid and a metal-contg. azo dye as electrostatic charging agents are incorporated into toner particles consisting essentially of resin and magnetic powder. The pref. amts. of the humic acid and the metal-contg. azo dye incorporated are 0.1-10wt.% each. The proper amt. of the magnetic powder in the toner particles is 10-70wt.%, especially 30-60wt.%. The dispersibility of the magnetic powder in the binding resin is improved by treatment with a silane or titanium coupling agent. The humic acid and the metal-contg. azo dye provide stable negative chargeability to the toner particles by synergism and prolong the service life.