Crash cooling method to prepare toner
AssigneeLexmark International, Inc.
InventorsKasturi Rangan Srinivasan, Rahel Bekru Bogale, Trent Duane Peter, Brian David Munson
Life of this patent
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Abstract
The present disclosure relates generally to a method to make a chemically prepared toner that employs a crash cooling process. In particular, the crash cooling process involves the addition of a toner slurry having a temperature between 70° C. and 90° C. to an equivalent amount of cold water having a temperature between 5° C. and 20° C. Polyester and styrene acrylic toners as well as polyester core shell toners having a borax coupling agent between the toner core and toner shell made from this cooling process results in an improvement to the amount of toner waste, thereby achieving a higher toner usage efficiency for an electrophotographic printing system.
Claims4
A method for producing a core shell toner, comprising:
- combining and agglomerating a polymer emulsion with a colorant dispersion and a release agent dispersion to form toner cores;
- combining and agglomerating a second polymer emulsion with the toner cores to form toner shells around the toner cores;
- fusing the aggregated toner cores and toner shells to form toner particles;
- forming a hot toner slurry by suspending the toner particles in an aqueous medium wherein the hot toner slurry has a temperature between 70° C. and 90° C.;
- adding the hot toner slurry to cold water in an external container wherein the cold water has a temperature between 5° C. and 20° C. and the quantity of the hot toner slurry is equivalent to the quantity of the cold water;
- filtering the toner particles out of the hot toner slurry;
- washing the filtered toner particles with deionized water;
- and
- repeating the filtering and washing steps until the conductivity of the filtered toner particles less than or equal to 5 μS/cm.
Dependencies are inferred from the claim text.