Patent ID: 7550242

Claim:
A toner, comprising: a core comprising a colorant, a release agent and a binder resin (A); and a shell comprising a binder resin (B), which is located overlying the core, wherein the binder resin (A) comprises a resin having a polyester skeleton, the binder resin (B) comprises a vinyl copolymer resin, and a weight ratio of the shell to the core is from 0.05 to 0.5, and wherein the toner has a volume average particle diameter of from 3 to 8 μm; wherein the shell comprising the binder resin (B) is formed by aggregating a particulate vinyl copolymer resin using an aggregation agent; and wherein the aggregation agent comprises Mg 2+ , and the toner has a fluorescent X-ray intensity of a peak specific to a Mg-Kα X-ray of from 3 to 30 Kcps.