Optical anisotropy conversion of retarder film made of rodlike and crosslike reactive molecules, and its dependence on the relative ratio and the orientation of the constituent molecules

Abstract

We reported an optical anisotropy conversion of a retarder film composed of rodlike and crosslike reactive molecules. We investigated the dependence of the optical anisotropy of the composite film on the relative ratio and the orientation of the constituent molecules. We used the rodlike molecule as a host and the crosslike molecule as a guest. We prepared the retarder films which were composed of various concentration of the constituent molecules. The retarder film showed + c plate-like property when no guest was used. On the other hand, the optical anisotropy of the film was gradually changed to + b, z, and –b plate when the guest concentration was increased to 5, 10 and 20 wt%, respectively. From the Fourier Transform-Infrared (FT-IR) dichroism measurement of the retarder films, it was found that the host molecules were vertically aligned when no guest was doped. The host molecules were tilted by doping the guest and then the in-plane optical anisotropy was shown. Consequently, the sign of the ratio of the out-of-plane optical anisotropy to the in-plane optical anisotropy was converted from negative to positive with its magnitude reduced.