US Patent 7286279 Microencapsulation processes and compositions for electrophoretic displays

The present invention is directed to a method for improving the performance of an electrophoretic display, which method comprises adding a fluorinated quaternary nitrogen salt in either the internal phase or the continuous phase in a microencapsulation process for the formation of pigment-containing microparticles. One or more of the following materials may be further added to the internal phase or continuous phase in the microencapsulation process: a fluorinated protective colloid, a second charge controlling agent or a second monomer or oligomer.