Crash cooling method to prepare toner
View Patent ↗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.
1. 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.
2. The method of claim 1 , wherein the hot toner slurry has a temperature between 80° C. and 84° C.
3. The method of claim 1 , wherein the cold water has a temperature between 7° C. and 14° C.
4. A toner prepared by the process of claim 1 .