Abstract: Microcapsules for electrophoretic display were prepared by in situ polymerization of urea-formaldehyde, in which organic pigment of benzidine yellow (PY-12) was used as displaying particles, tetrachloroethylene and toluene as dispersion media, oil soluble blue N dye as light absorber and super dispersant CH-2C as stabilizing agent. The morphology and size of microcapsules were checked through optical transmission microscope. The response to the change of electric field and display performance of the microcapsules were investigated. It was shown that the microcapsules without pigment particles made by this method were of good smoothness and transparence. Fast and reversible display of the microcapsules with pigment particles was achieved in an electric field.

Key words: Electrophoretic ink, Electrophoretic display, Microcapsule, Urea-formaldehyde, In situ polymerization