Preparation of Dispersants for Color Inks and its Application in Electrowetting Display

With condensation reaction of amino-anthraquinone and polyisobutyl maleic anhydride, two kinds of dispersing agents are prepared for electrophoretic non-polar ink materials with amino-anthraquinone as anchoring group and polyisobutylene as cosolvent group. The anchoring group of the novel dispersant is an anthracene ring, which has a high structural similarity with an anthraquinone-based organic pigment, so the anchoring group has a good adsorption force with the dispersed pigment; meanwhile, it has 22 carbon atoms. The polyisobutylene long-chain group is a ultra- solubilizing group in the electrowetting ink system, and its large molecular weight provides spatial stereo protection for improving the solubility and stability of the dispersed ink system., and is prepared. With the mechanical grinding method, the electrowetting display dispersing ink material with higher absorbance is obtained with the dispersing red-FB as a pigment and with the 1:1, 1:2 and 1:3 mass ratios of the dispersing agent and the dispersed red-FB. The average particle size is 267 nm. The device application test shows that the dispersed ink material has good device response performance.