Patent ID: 6054244
Filing Date: 2000-04-25
Classification: G03G

Abstract:
A process for producing a toner, comprising;adjusting to from 4.0 to 6.0 pH of an aqueous medium containing a calcium phosphate, which is prepared 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;polymerizing in the aqueous medium the polymerizable monomer contained in the particles, to form toner particles; andadjusting the pH of the aqueous medium to from 1.0 to 3.0 to dissolve the calcium phosphate, followed by separating the toner particles from the aqueous medium;said toner particles having a circularity of from 0.970 to less than 1.000 as measured with a flow type particle image analyzer.