| abstract |
(57) [Problem] To provide a granular magnetite particle powder suitably used for a magnetic toner for electrophotography and a resin dispersion type carrier. SOLUTION: 0.1 to 20% by weight of an aqueous resin or And granular magnetite particles coated with SiO 2 . Preferably, the magnetite has a bulk density measurement time in a powder tester of 40 seconds or less and a stirring torque of 0.016 kg ยท m or less. As the aqueous resin, vinyl acetate, an emulsion resin containing vinyl acetate-acrylic copolymer as a main component, a water-soluble resin, an alkyd type, a colloidal dispersion resin containing an epoxy ester type as a main component, an alkyd type, A water-soluble resin whose main component is an acrylic resin can be preferably used. |