| 摘要 |
PURPOSE:To obtain an insulative magnetic toner capable of providing picture images having elevated image density and preventing generation of fog by using a polyester resin as binder resin, admixing hydrophobic colloidal silica with the toner, and specifying a degree of coagulation of the toner. CONSTITUTION:A polyester resin is incorporated into an insulative magnetic toner as binder resin. Hydrophobic colloidal silica is also admixed therewith, and a degree of coagulation of the mixture is adjusted to 1-20% at 25 deg.C and 60% humidity. Thus, an insulative magnetic toner usable for obtg. copies having high faithfulness to an original and providing stable picture quality is obtd. The magnetic toner is also usable in a development aiming elimination of tissue fogs due to environmental changes, particularly at high humidity, and prepn. of uniform picture images having sufficient density and high definition. |
