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US 6,582,873 B2Granted
Toner coagulant processes
AssigneeXerox Corporation
InventorsLu Jiang, Nan-Xing Hu, Raj D. Patel, Walter Mychajlowskij, Michael A. Hopper
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Abstract
A toner process including, for example, mixing a latex with a colorant wherein the latex contains resin and an ionic surfactant, and the colorant contains a surfactant and a colorant; adding a polyaluminum chloride; affecting aggregation by heating; adding a chelating component and a base wherein the base increases the pH of the formed aggregates; heating the resulting mixture to accomplish coalescence; and isolating the toner.
Claims8
A toner process comprising
- (i) blending a colorant dispersion of a colorant, water, and an ionic surfactant with a latex emulsion comprised of resin, water, and an ionic surfactant;
- adding to the resulting blend containing the latex and colorant a coagulant of polyaluminum sulfosilicate, aluminum sulfate, or polyaluminum chloride with an opposite polarity to that of the ionic surfactant in the latex emulsion to thereby initiate flocculation of the resin latex and colorant;
- heating the resulting mixture below about the glass transition temperature (Tg) of the latex resin to form a suspension of toner aggregates;
- optionally adding a second latex comprised of resin particles suspended in an aqueous phase to the formed toner aggregates resulting in a coating or a shell wherein the shell is optionally of from about 0.1 to about 1 micron in thickness;
- adding an organic chelating agent to the resulting mixture, followed by adjusting the mixture resulting with a base thereby resulting in a ph of about 5 to about 9;
- heating the resulting aggregate suspension above about the Tg glass transition temperature of the latex resin;
- and changing the pH of the resulting mixture by the addition of a metal salt to arrive at a pH in the of about 2.8 to about 5, and isolating said toner.
4 more elements
Dependencies are inferred from the claim text.