Defect-Free FLCD's with High Optical Quality Based Upon New FLC's

We have designed new FLC compounds and new FLC materials based upon them, and we have found general criteria of the preparation of FLCD's with uniform and stable orientation of FLC materials [1]. The influence of the molecular structure on the quality of orientation, on thermal and mechanical stability and on the contrast ratio was investigated by using 4 types of aligning materials in the thin and thick testing cells. The correlation between the number, type and amount of achiral and 3-, 4-ring chiral compounds in the mixture and contrast ratio of our FLCD's was found. Finally we optimized the FLC-mixtures, alignment conditions and we prepared the defect-free samples with optical contrast about 700:1.