High Reliability Fluorinated Diluter and Reactive Monomer Solubilized in Liquid Crystal Compounds and Application toward Liquid Crystal Displays

Abstract

Diluters play crucial role for reducing rotational viscosity of liquid crystal (LC) materials for improvement of response speed of LC displays (LCDs). However, conventional diluters tend to deteriorate relatively easily under ultraviolet (UV) exposure due to existence of vinyl groups. Hence it was difficult to prepare polymer layers in the LC cells by exposing UV for polymerization regarding polymer sustained alignment (PSA) and polyimide-free (PI-free) technologies. In this study, however, we succeeded in development of a highly reliable fluorinated diluter C3-CyFF-Cy-C3 (Cy : cyclohexane group, C3 : propyl group, F : fluorinated group) under the UV exposure, which carries fluorinated groups for inducing stable nematic phase and high affinity with other fluorinated LC compounds. We succeeded in developing the PSA and the PI-free in-plane switching mode LC cells with the diluter developed in this study. The LC cells with the polymer layers formed by the monomer carrying an azobenzene moiety showed both fast response speed and high stability under the UV exposure.