Patent ID: 7514193

Claim:
A developing toner for electrostatic latent images comprising: coloring resin particles containing a binder resin and carbon black; and hydrophobic fluidizing particles deposited on surfaces of the coloring resin particles, the binder resin containing a polyester resin, a polyalkylene selected from the group consisting of a paraffin wax, an oxidized polyethylene wax, a polypropylene wax, a polybutene wax, an ethylene-propylene copolymer wax, an ethylene-butene copolymer wax, and a non-oxidized polypropylene; a polyolefin dispersant and a non-oxidized polyethylene wax, in which the polyolefin dispersant is a polyolefin dispersant selected from a polyolefin resin having a side chain of a styrenic polymer chain or styrene (meth)acrylic polymer, wherein the amount of carbon black is 10 to 20 parts by weight based on 100 parts by weight of a polyester resin, the amount of the hydrophobic fluidizing particles having a specific surface area of from 110 to 200 m 2 /g, are from 1.2 to 2.8 parts by weight based on 100 parts by weight of the coloring resin particles, and a time constant τ of the toner being from 135 to 220 msec, wherein the polyester resin consists of an unsaturated polyester resin which is synthesized from raw materials consisting of a polybasic acid and a polyhydric alcohol under the presence of a catalyst in an organic solvent, the polyester resin having an acid value of from 20 to 25 mg KOH/g and a hydroxyl value of from 11 to 17 mg KOH/g.