PURPOSE: To provide the titled element capable of forming optical image corresponding to the optical signal transmitted from He-Ne laser, YAG laser, semiconductor laser and Ar laser, comprising a liquid crystal composition containing specific azulenium compound.
CONSTITUTION: The objective element comprising a liquid crystal composition containing pref. 1W5wt% of an azulenium compound of formula [R1, R1', R2, R3, R3', R4, R4', R5, R5', R6, R6', R7 and R7' are each H, halogen or monovalent organic residue (e.g. alkyl, alkoxy, aryl, aralkyl, acyl, amino, etc.), Z- is anonic residue]. Said compound will be prepared by the reaction, in a solvent such as alcohol or nitrile in the presence of strong acid at room temperature- boiling point, between 1,3-diformyl azulene compound and the orginal azulene compound.
OGUCHI YOSHIHIRO
KANBE JIYUNICHIROU
TAKASU YOSHIO
