Patent ID: 7618760

Claim:
A two-component developer comprising: a toner containing toner particles which contain a binder resin and a colorant, resin microparticles adhering to surfaces of the toner particles, and silica microparticles adhering to the surfaces of the toner particles; and a carrier containing magnetic particles and resin coat layers coated on surfaces of the magnetic particles, wherein a rate of change ΔA (%) in BET specific surface area A (m 2 /g) of the toner expressed by the expression (i) ΔA=((A 120 −A 1 )/A 1 )×100, and a rate of change ΔC (%) in charge quantity C (μC/g) of the carrier expressed by the expression (ii) ΔC=((C 120 −C 1 )/C 1 )×100, when a mixture of the toner and the carrier is stirred and mixed by a TURBULA shaker mixer are both within 10%, and wherein, in the above-described expressions (i) and (ii), A 1 indicates a BET specific surface area (m 2 /g) of the toner when the mixture of the toner and the carrier is stirred and mixed for 1 minute by a TURBULA shaker mixer, A 120 indicates a BET specific surface area (m 2 /g) of the toner when the mixture of the toner and the carrier is stirred and mixed for 120 minutes by a TURBULA shaker mixer, C 1 indicates a charge quantity (μC/g) of the carrier when the mixture of the toner and the carrier is stirred and mixed for 1 minute by a TURBULA shaker mixer, and C 120 indicates a charge quantity (μC/g) of the carrier when the mixture of the toner and the carrier is stirred and mixed for 120 minutes by a TURBULA shaker mixer.