MAGNETIC TONER AND ELECTROPHOTOGRAPHIC METHOD

摘要

PURPOSE:To attain high image quality by using a magnetic toner contg. melamine-based fine particles having a specified average particle diameter and negative charge type fine silica particles having a specified BET specific surface area by nitrogen adsorption. CONSTITUTION:This magnetic toner consists of a bonding resin, a magnetic substance and additives which are melamine-based fine particles having 0.01-12mum average particle diameter and 0.1-50m<2>/g BET specific surface area by nitrogen adsorption and negative charge type hydrophobic fine silica particles having 50-350m<2>/g BET specific surface area by nitrogen adsorption. The silica particles are preferably surface-treated with silicone oil and contained by 0.01-5.0 pts.wt. per 100 pts.wt. of this magnetic toner. The magnetic substance is preferably contained by 15-70wt.% of the amt. of this magnetic toner. High image quality with high image density and low surface fog can be attained and filming on a photoreceptor can be prevented even in use over a long period of time.