Patent ID: 7008747

Claim:
A process for producing a polymerized toner, comprising the step of subjecting a monomer composition comprising a polymerizable monomer and a colorant to suspension polymerization in an aqueous dispersion medium containing a dispersion stabilizer to form colored polymer particles, wherein at least one water-soluble compound selected from the group consisting of water-soluble boron compounds and water-soluble phosphorus compounds is caused to exist in the aqueous dispersion medium to conduct the suspension polymerization, wherein the production process comprises forming colored polymer particles (A 1 ) by the step of subjecting a monomer mixture containing a polymerizable monomer and a colorant to suspension polymerization and then adding the step of polymerizing a polymerizable monomer, which is capable of forming a polymer having a glass transition temperature higher than that of the polymer component making up the colored polymer particles (A 1 ), in the presence of the colored polymer particles (A 1 ) to form a layer of the polymer having a higher glass transition temperature on the surfaces of the colored polymer particles (A 1 ), thereby forming a polymerized toner composed of core-shell type colored polymer particles (A 2 ).