| abstract |
Additives for electrophoretic media comprising esters of branched polyols and fatty acids, such as esters of pentaerythritol propoxylate (5/4 PO/OH) and stearic acid. The fatty acids may be saturated or unsaturated, branched or unbranched. In some embodiments, the fatty acids are perfluorinated, or partially fluorinated. In some embodiments, the branched polyol will include oligomers of polypropylene oxide or polyethylene oxide. When the additives are included in an electrophoretic medium in a display, the resulting display has an improved contrast ratio and reducing ghosting. |