Magnetic particle powder null for magnetic toner

摘要

PURPOSE:To provide the fine magnetic powder high in water repellency usable for the magnetic toner and superior in environmental stability and dispersibility in a binder resin. CONSTITUTION:The magnetic powder coated on the surface with an aluminum compound A containing a fluorocarbon chain for the magnetic toner is prepared by (1) adding the aluminum compound A directly to the magnetic powder M and pulverizing both by using a Henschel mixer, a ball mill, an atomizer, a colloid mill, and the like, or (2) adding the compound A and the powder M in an organic solvent, stirring and mixing them, and removing the solvent, or (3) adding the compound A into a mixture of the organic solvent and the powder M and treating them with a heat roll or the like.