The Synthesis Of Colorants For Color Display Of The Smectic Liquid Crystal

Smectic liquid crystal is a new type of electronic display materials with very promising application prospect. Because of the commercial available smectic phase liquid crystal display could shows monochrome image only currently, and refer to the development path of the display, the color display is an inevitable trend, it is necessary to find and add the appropriate colorant for color display.According to the features and specific characters of the smectic liquid crystal, several amino anthraquinones derivatives and quinolinone derivatives were designed and synthesized as liquid crystal coloring agent. The influence of reaction conditions such as catalyst and temperature were discussed as well as catalytic mechanism. Their application performance were investigated in the smectic phase LCD.Because of the better performances of heat-resistance and light-resistance as well as the stabilities than the azo colorants, anthraquinone colorants were considered for color display preferred, but the anthraquinone colorants have poor solubility in the normal organic solvents, and the introduction of the alkoxy chain in anthraquinone could be a good solution. With sodium hydroxide as base and ethanol as solvent, several kinds of p-alkoxy bromobenzene and p-alkoxy phenol were synthesized by Williams etherification reaction,10amino anthraquinones derivatives were synthesized by Ullmann condensation reaction of amino anthraquinone and of p-alkoxy bromobenzene used Cu/CuCl as catalyst, Which are yellow or red coloring agent. In addition, a quinolinone derivative was synthesized as yellow colorant by reaction of α-methyl quinoline and phthalic anhydride. The reaction conditions were optimized. All of the molecules synthesised were characterized by1H NMR and Mass. They were added into a specific smectic phase liquid crystal as colorants, respectively. Their solubility, store-stability and the transmittances both in haze and transparent states as well as driving speed in the liquid crystal were measured. The results indicated that they dissolved well in the smectic phase liquid crystal, with fast driving speed and the reasonable ratio of transmittance in haze and transparent states, implying they could meet the requirements for color display in the smectic phase liquid crystal.