2,2'-difluoro-4-alkoxy-4'-hydroxydiphenyls and their derivatives, their production process and their use in liquid crystal display devices

摘要

The invention relates to novel compounds usable as liquid crystals in liquid crystal display devices utilizing the electrically controlled birefringence effect. These compounds comply with formula: <IMAGE> (I) in which R1 represents an alkoxy or alkyl radical with 1 to 12 carbon atoms and Z represents a single bond or a radical chosen from among: <IMAGE> provided that R1 represents an alkyl radical when Z represents a single bond and R2 represents an alkyl radical with 1 to 12 carbon atoms. They can be obtained by reacting an acid chloride of formula R1-z-COCL with a 2,2'-difluoro-4-alkoxy-4'-hydroxydiphenyl of formula: <IMAGE> (II)