Patent ID: 8450040

Claim:
A method of making toner particles, comprising: a) mixing at least one emulsion of at least one resin, a colorant, an optional wax, and optional additives to form a slurry, wherein said at least one resin includes a first amorphous resin, a second amorphous resin different than said first amorphous resin, and a crystalline resin; b) heating the slurry to an aggregation temperature to form aggregated particles in the slurry; c) freezing aggregation of the particles with a buffer solution, the buffer solution comprising: an organic compound selected from the group consisting of tris(hydroxymethyl)aminomethane (“TRIS”), Tricine, Bicine, Glycine, HEPES, Trietholamine hydrochloride, and MOPS; and an acid selected from the group consisting of an aliphatic acid, an aromatic acid, acetic acid, citric acid, hydrochloric acid, boric acid, formic acid, oxalic acid, phthalic acid, and salicylic acid; d) increasing a temperature of the aggregated particles and slurry to a coalescing temperature without addition of any pH adjustment agent; and then e) allowing the aggregated particles to coalesce into toner particles, wherein the freezing aggregation of the particles with the buffer solution comprises: adjusting the pH of the slurry to about 3.5 to about 6 using the buffer to make an adjusted slurry, adding to the adjusted slurry a chelating agent, and further adjusting the pH of the adjusted slurry to about 6 to about 9 using the buffer.