Liquid crystal alignment composition

Abstract

A liquid crystal alignment composition contains at least one polymer and a mixed solvent. The polymer is polyamide acid, polyimide or the combination of both, and the mixed solvent is the combination of butyl cellosolve and nitrogen-ispropyl-2-pyrrolidone or the combination of butyl cellosolve, nitrogen-ispropyl-2-pyrrolidone and aiding solvents, wherein the aiding solvents can improve the solubility of the mixed solvent to the polymer. When the composition is applied to a substrate during the use of an ink jet printing mode, the polymer precipitation risks can be reduced; in the applying process, the liquid crystal alignment composition has stable drop applying condition and high collimation, and shows excellent diffusivity and leveling property 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.

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