Newly Synthesized Polyimide for Aligning Nematic Liquid Crystals Accompanying High Pretilt Angles

Abstract A series of special polyimides was synthesized to use them for aligning nematic liquid crystals accompanying a pretilt angle from a few degrees up to 30 degrees by using a rubbing technique. The chemically synthesized polyimide is comprised of two parts: one is an ordinary long-chain polymer and the other is an extra chemically attached hydrocarbon branch with a finite length. The former part is considered to play a role in aligning liquid crystals in a single direction due to the rubbing and the latter is responsible for producing a high pretilt angle if appropriate rubbing is done. This newly synthesized polyimide was successfully used to make a supertwisted nematic liquid crystal display with 270 degrees twist and 12 degrees pretilt.