Patent ID: 6103437
Filing Date: 2000-08-15
Classification: B82Y,C01G,C01P,G03G,Y10S,Y10T

Abstract:
A magnetic toner comprising magnetic iron oxide particles, together with a binder resin, having at least 60%, in particle number, magnetite particles having an average particle diameter of 0.05 to 0.50 .mu.m containing 0.9 to 6.5 atomic % of silicon, calculated as an element Si, based on Fe each of said magnetite particles having a plurality of mountain-shaped protrusions with unsharpened crests on a surface of each particle, and the number of said mountain-shaped protrusions formed on the surface of each magnetite particle being in the range of 2 to 30 when viewed in projected plan, wherein the magnetite particles satisfy the formulae (I) and (II):0.10.ltoreq.x/z.ltoreq.0.40 (I)0.05.ltoreq.y/z.ltoreq.0.30 (II)wherein x represents a bottom length of each of mountain-shaped protrusions, y represents a height each of mountain-shaped protrusions, and z represents an average particle diameter of the magnetite particle on which the mountain-shaped protrusions are present.