Price: 10.00
In liquid crystal (LC) display, primary alignment of the LC molecule is generally performed on the polyimide thin film by mechanical rubbing. It has been, however, desired non-contacting method, what is called the rubbing free technique, because of many problems on the rubbing process such as evolution of dusts and electrostatics. In recent years, the alignment of liquid crystal with the control of molecular orientation by the photochemical reaction under irradiation of linearly polarized light (LPL) has attracted attention due to practical possibility as a rubbing free It has been reported that the LC photoalignment is performed with the mechanism based on cis-trans conformational or photodissociation of Poly(vinyl cinnamate)s, PVCis ,which have photoreactive site in side chain to be crosslink have been investigated for photoalignment. We previously proposed the photoalignment materials, poly(oxyalkyleneoxy-1 ,4-phenylenediacryloyl), PDA-n, containing the photoreactive site in main chain. They have the ability to align the nematic liquid crystal in the direction on perpendicular to that of the We newly prepared a series of polyester, CPCA-n (n = 3-5), which have a similar structure to be liquid crystal molecule as shown in Fig. 1. In addition we prepared some CPCA-n derivatives introduced one or two methoxy groups to benzene ring next ethenylene in the molecule. We report herein the photoalignment films of CPCA-n and the derivatives and discuss the effect of the molecular structure on the reaction induced by LPL and that on the LC alignments.
