Liquid crystal alignment composition

Abstract

A liquid crystal alignment composition, including at least one polymer and a mixed solvent. The polymer is selected from polyamic acid, polyimide or a combination of the above two. The mixed solvent is selected from ethylene glycol butyl ether. The combination with nitrogen-isopropyl-2-pyrrolidone, or the combination of ethylene glycol butyl ether, nitrogen-isopropyl-2-pyrrolidone and an auxiliary solvent, wherein the auxiliary solvent can increase the effect of the mixed solvent on the polymer. solubility. The composition can reduce the risk of polymer precipitation during the process of coating on the substrate using inkjet printing, and enables the liquid crystal alignment composition to have stable droplet coating conditions and high collimation during the coating process. In addition, it also has excellent diffusion and leveling properties on the substrate.

Description

technical field [0001] The present invention relates to a liquid crystal alignment composition, in particular to a liquid crystal alignment composition suitable for inkjet printing and coating. Background technique [0002] Liquid crystal displays mainly use an external electric field to change the alignment state of liquid crystal molecules, thereby causing changes in the polarization state and direction of light, so as to obtain a display effect of light and dark contrast. [0003] With the enlargement of the screen size, the liquid crystal display has been developed to a liquid crystal display element equipped with a thin-film transistor (Thin-Film Transistor, TFT) in each pixel. When the liquid crystal molecules are placed between a pair of substrates containing electrodes, the alignment of the liquid crystal molecules needs to be controlled by controlling the electric field because the dielectric constants of the liquid crystals are different between directions parallel...

AI Technical Summary

Problems solved by technology

[0006] However, although the existing inkjet printing technology has many advantages over roller printing, there are still many technologies to be overcome, such as liquid crystal alignment for coating on the substrate and forming a liquid crystal alignment film in inkjet printing. Composition, in the coating process, in addition to reducing the risk of precipitation of the alignment film material of polyamic acid or polyimide, it also needs to have stable droplet coating and high alignment, and the alignment composition It should also have excellent diffusion and leveling properties on the substrate to avoid uneven diffusion or uneven film thickness of the formed alignment film.

Images