Patent ID: 7186494

Claim:
A process for forming a toner, comprising: mixing a pigment dispersion with a polymer latex resin, a wax dispersion, and a metal halide coagulant in water, wherein the polymer latex resin contains a polymer selected from the group consisting of poly(styrene-butyl acrylate) and poly(styrene-butyl acrylate-β-carboxyethyl acrylate); forming aggregates by heating the mixture at an aggregation temperature below the glass transition temperature of the latex resin; increasing the pH of the aggregates with a base; and coalescing the aggregates by heating the mixture at a coalescence temperature above the glass transition temperature of the latex resin and lowering the pH to between 5 to 6.5 with an acid to form toner particles; wherein the polymer latex has a static yield stress of about 0.5 dyne/cm 2 and a viscosity of about 17.26 centipoises (cps); and wherein the toner possesses a volume average particle size distribution index GSDv of about 1.19, a number average particle size distribution index GSDn of about 1.22, a low number average particle size index GSDn 50/16 of about 1.25, and a ratio of the volume average particle size distribution index GSDv to a number average particle size distribution index GSDn of about 0.975.