Preparation and application of microcapsule-encapsulated color electrophortic fluid in Isopar M system for electrophoretic display

The use of Isopar M as a liquid suspending fluid for electrophoretic display was studied. The dispersion stability and chargeability of pigments suspended in Isopar M were investigated. Polyisobutylene monosuccinimide (T-151) as the charge control additive in Isopar M electrophoretic fluid can provide a good electrophoretic mobility to the particles. The wall materials of a series of blue–white, red–white and yellow–white dual-particle microcapsules were prepared by in situ polymerization of urea and formaldehyde. The mass ratio of wall/core material was a key factor in influencing the yield of microcapsules. The concentration of resorcinol has an impact on the surface morphology and mechanical strength of microcapsule wall. Microcapsules’ surface morphologies were characterized by optical microscopy and scanning electron microscopy. The performance of the microcapsules with different binder materials and adhesive layers were investigated. Contrast ratio of microcapsules display device were tested every 10 days for a period of 90 days. The compatibility of Isopar M with both the electrophoretic particles and bounding capsule was studied.

► Isopar M was chosen as dispersion medium for electrophoretic dispaly.
► Microcapsules were prepared by in situ polymerization containing Isopar M fluid.
► An appropriate dosage of resorcinol can help to shape microcapsule.
► The contrast ratio of electrophoretic display device was improved.
► The electrophoretic display device prototype possesses a longer working life.