Preparation of polyimide alignment films with high photosensitivity and low solid content

In order to reduce the cost, a polyimide (BF-CA) with high photosensitivity and low solid content was prepared by one-step method using 2,2-bis (3-amino-4-hydroxyphenyl) propane (BAP), 4,4'-(hexafluoroisopropyl) phthalic anhydride (6FDA) as monomer and cinnamoyl chloride as photosensitive group. The BF-CA films exhibit good alignment performance after non-polarised ultraviolet light (NPUVL) irradiation for 20 minutes. Meanwhile, the effect of solid content on the alignment performance is mainly discussed, because reducing solid content helps to reduce costs. In addition, the BF-CA shows good thermal stability. The pretilt angle of the liquid crystal cells is 0.5 degrees, which meet the requirements of practical application in In-Plane Switching liquid crystal display.

Automated summary

A polyimide (BF-CA) with high photosensitivity and low solid content was prepared using a one-step method, showing good alignment performance after NPUVL irradiation. The study highlights the importance of reducing solid content to lower costs and achieve good alignment performance for liquid crystal cells. The thermal stability of BF-CA was also demonstrated, meeting the requirements for practical applications in In-Plane Switching liquid crystal displays.