| abstract |
PURPOSE: A liquid crystal composition having a large order parameter in a host liquid crystal and presenting a bright color in a small amt., which contains a specified anthraquinone pigment. n CONSTITUTION: A compd. of formula I [wherein X is O, S or -NR-(wherein R is H or lower alkyl); Ar is an aryl group having a substituent such as an aryl group, an alkyl group or halogen] is reduced with NaS, hydrazine, etc. to obtain an anthraquinone pigment of formula II. Then 0.1W10wt% said anthraquinone pigment is added to a host liquid crystal material contg. an optically active material. n EFFECT: The pigment is excellent in stability to light, heat, water, oxygen, etc. and largely soluble in a liquid crystal, giving arbitrary concentration required, and exerts no inferior influence on the electricl characteristics of an element by ion dissociation, etc. n COPYRIGHT: (C)1981,JPO&Japio |