Black non-magnetic composite particles for black toner and black toner containing the same

摘要

Black non-magnetic composite particles for black toner according to the present invention have an average particle size of from 0.08 to 1.0 mu m and comprise: (i) black hematite particles or black iron oxide hydroxide particles as core particles; (ii) fine particles on at least a part of the surface of each magnetite particle, comprising an oxide and/or an oxide hydroxide of at least one element selected from Si, Zr, Ti, Al and Ce; and (iii) a methyl hydrogen polysiloxane coating layer on said fine particles or on said fine particles and the exposed surface of the core particles. Such black non-magnetic composite particles are suitable for a black toner which can exhibit not only an excellent flowability but also a high volume resistivity.