Patent ID: 8124306

Claim:
A magnetic toner comprising at least a binder resin and a magnetic material, wherein the magnetic material is magnetic iron oxide whose dielectric breakdown voltage is 160 to 1600 V/cm, the dielectric loss tangent (tan δ) of the magnetic toner at 100 kHz and 40° C. is 2.0×10 −3 to 1.0×10 −2 , the magnetic material contains aluminum (Al) at an amount of 0.5 to 5.0 mass %, the aluminum dissolution percentage with respect to the total Al content of the magnetic material is 40 to 60 mass %, when the magnetic material is washed with a 1 mol/L aqueous sodium hydroxide solution, the aluminum dissolution percentage with respect to the total Al content of the magnetic material is 60 to 85 mass %, when the magnetic material is dissolved in a 1 mol/L aqueous hydrochloric acid solution so that the iron dissolution percentage with respect to the total iron content of the magnetic material is 20 mass %, the aluminum dissolution percentage with respect to the total Al content of the magnetic material is 80 to 95 mass %, when the magnetic material is dissolved in a 1 mol/L aqueous hydrochloric acid solution so that the iron dissolution percentage with respect to the total iron content of the magnetic material is 60 mass %, and the aluminum dissolution percentage with respect to the total Al content of the magnetic material is 95 to 99 mass %, when the magnetic material is dissolved in a 1 mol/L aqueous hydrochloric acid solution so that the iron dissolution percentage with respect to the total iron content of the magnetic material is 80 mass %.