Process for producing toner

摘要

A process for producing a toner comprises the steps of: adjusting to 4.0 to 6.0 the pH of an aqueous medium containing a calcium phosphates obtained by mixing an aqueous phosphate solution with an aqueous calcium salt solution; dispersing in the aqueous medium a polymerizable monomer composition having at least a polymerizable monomer, a colorant, a polar polymer or polar copolymer having a carboxyl group, and a polymerization initiator to form particles of the polymerizable monomer composition; in the aqueous medium, polymerizing the polymerizable monomer contained in the particles to form toner particles; and adjusting the pH of the aqueous medium to 1.0 to 3.0 to dissolve the calcium phosphate, followed by separating the toner particles from the aqueous medium. The circularity of the toner obtained is not less than 0.970 and less than 1.000 as measured with a flow-type particle image analyzer (FIPA).