Charge control agents and particle dispersions including the same
AssigneeE Ink Corporation
InventorsEugene Bzowej, John L. Marshall, Stephen J. Telfer, Brandon Macdonald
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Abstract
Mixtures are disclosed containing a plurality of charged pigment particles and one or more charge control agents. At least one of the charge control agents has a chemical structure that includes a cationic head group, such as an ammonium cation or an iminium compound, and a non-ionic, polar functional group, other than an acyclic secondary amide group. The mixtures are useful as dispersions for forming electrophoretic media that may be incorporated into electrophoretic displays. Alternatively, the dispersions may be useful for forming electrophotographic toners and dispersions for other printing applications.
Claims13
An electrophoretic medium comprising a dispersion comprising a non-polar fluid, a plurality of charged particles and a blend of a first charge control agent and a second charge control agent, wherein the first charge control agent comprises a cationic head group and having a chemical structure according to Formula I;
- wherein m is 0, 1, 2, or 3;
- wherein each R is independently selected from the group consisting of an alkyl group, and an aryl group;
- wherein Z is one of a branched alkanediyl group, and an unbranched alkanediyl group;
- wherein n is an integer less than or equal to 20;
- wherein HT is a hydrophobic moiety;
- the second charge control agent being represented by Formula XV, Formula XVI, or Formula XVII;
- wherein each R21, R22, R23 is independently selected from the group consisting of an alkyl group or an aryl group;
- wherein v is an integer of at least 2 and less than or equal to 20;
- wherein HT is a hydrophobic moiety;
- wherein HT of Formulas XVI and XVII is a hydrophobic moiety comprising a functional group selected from the group consisting of poly(hydroxystearic acid), poly(ricinoleic acid), poly(isobutylene), and an unbranched or a branched alkyl group, wherein the unbranched or the branched alkyl group comprises from about 10 to about 35 carbon atoms,
- and wherein the plurality of charged particles are capable of moving through the non-polar fluid upon application of an electric field.
Dependencies are inferred from the claim text.