THE PREPARATION OF ELECTROPHORETIC INK MICROCAPSULES BY USING UREA FORMALDEHYDE OLIGOMER

In the process of preparing electrophoretic ink microcapsules by in-situ polymerization,oligomers instead of traditional prepolymers (hydroxymethyl urea and dihydroxymethyl urea) of urea-formaldehyde were used as monomers of reaction,because oligomers are more likely to be adsorbed on the surface of oil phase droplets.The general problems of in-situ polymerization such as coagulating,sticking,coarse surface,low productivity etc.have been solved.The properties of viscosity and surface activity of urea-formaldehyde oligomers were studied,as well as their relationship with the encapsulation efficiency of microcapsules.The electrophoretic ink microcapsules were prepared successfully by this method.