| 摘要 |
PURPOSE:To improve the contrast of a display image and an extend service life of a display element, by using a specified anthraquinone-based red coloring matter with a high dichromatic ratio and excellent light resistance, as red colorant for a display element which utilizes a guest-host effect. CONSTITUTION:The liquid crystal display element is prepared by using a red coloring matter of formula I (where R is H, alkyl, alkoxyl, alkylthio, aryl, aralkyl, aryloxy, eetc.; R1 and R2 are H, alkyl, aryl, aralkyl, etc.) as dichromatic colorant to be contained in a liquid crystal compsn. for a display element. The red coloring matter of formula I is synthesized by reacting a phenolic compd. of formula III with a compd. of formula II in the presence of a deoxidizer. Examples of I are shown by formulas IV, V, etc.
|
