Patent ID: 7070897

Claim:
A two-component developer comprising a toner and a carrier for use in electrophotography, wherein said toner contains a magnetic powder as an external additive, said carrier is a resin coated magnetic carrier of 6.0 to 8.0 in true specific gravity, and the coating resin is a silicone based resin containing a crosslinking agent having a phenyl group and an aminosilane coupling agent, wherein the toner is mixed with a magnetic fine powder as an external additive, said magnetic fine powder is octahedral in shape and contains 1 to 3 wt % of magnetite having aminosilane groups on the surface thereof, the coating resin of said carrier has a content ratio of the aminosilane coupling agent ranging from 14 to 18 wt %, and a 50% average particle size based on volume of the magnetic carrier coated with the coating resin is 40 to 80 μm.