The invention relates to electrophoretic displays comprising core-shell pigment particles having a core of low specific gravity and low refractive index and a shell of high refractive index.
This application is a continuation-in-part of U.S. application Ser. No. 10/364,270, filed Feb. 10, 2003 now abandoned; which claims the benefit of Provisional Application No. 60,356,226, filed Feb. 11, 2002; the content of both are incorporated herein by reference in their entirety.
An electrophoretic ink includes fluid having either (a) at least two sets of differently colored particles with the fluid been a substantially clear fluid, or (b) at least one set of colored particles with the fluid been a differently colored fluid than the colored particles, wherein at least one set of colored particles includes at least one electrophoretic particle having a core-shell structure. The at least one electrophoretic particle includes a shell and a core located within the shell, wherein the core includes a colorant and a fluorescent compound. An electric field may be applied adjacently to the fluid of the ink, and the at least one set of colored particles having the core-shell structure is movable within the fluid of the ink by the electric field.
A method for preparing a nanodispersion comprising the steps of: (i) introducing into a milling apparatus a solid fluorinated phthalocycanine pigment according to Formula (I): ##STR00001## Wherein M is a metal cation chosen from Groups 1b, 2b, 2a or 3a of the Periodic Table of the Elements; R is fluorine, a perfluoroalkyl or a perfluoroaryl group; z is 1 to 4; L is an anionic ligand; and n is 0 or 1 such that the overall charge on the molecular unit is neutral; followed by milling with agitation the solid fluorinated phthalocyanine in an organic solvent into a suspension of particles so that at least 80 volume % of the particles have a particle size of less than 100 nm.
