US Patent 7749672 Polyester toner compositions

An emulsion aggregation polyester toner including a polyester resin having modified end groups, wherein the polyester resin includes at least one carboxylic end group. A process of making the toner by oxidation of a polyester resin including reacting the polyester with a hypohalite and a phase transfer catalyst results in a polyester resin endcapped with at least one acidic group. Stable xerographic charging in all ambient environments for all colors, and excellent resistivity and cohesion of the toner, may be achieved.