POSITIVE CHARGE TYPE TONER

摘要

PURPOSE: To obtain a toner excellent in environmental stability and stability of a charged state and capable of forming a clear developed image free from fog even by high-speed copying even after storage at high temp. CONSTITUTION: Fine silicon dioxide powder made hydrophobic by treatment is added to toner particles contg. at least a resin binder and a colorant so as to satisfy the formula 90<=S×A×B<310 [where S is the BET specific surface area (m<2> /g) of the fine silicon dioxide powder, A is the amt. (wt.%) of the fine silicon dioxide powder added to the toner particles and B is the rate (%) of surface coating of the toner particles with the fine silicon dioxide powder]. The objective toner is obtd.