Photochemical reaction on the polymer layer for liquid crystal display

Polyimide containing the chalcone moiety is expected to show the high photodimerization rate and stable alignment characteristics. We introduced the chalcone moiety as a side chain into the polyimide backbone to apply to the photo-alignment layer. The tilted angle of incident light produced out-of-the-plane orientation of chalcone side chain. The orientation effects align the LC in LCD, which possesses the various pretilt angles depending on the length of side chains.