Liquid crystal composition containing azo dyes

A liquid crystal composition containing azo dyes represented by the formula (I-1) ##STR148## wherein Y represents a hydrogen atom, an alkyl group, an alkoxy group, a nitro group, a cyano group, a carboxylic acid ester group, an acyloxy group, an aryl group, an alkylsulfonyl group, a halogen atom or ##STR149## wherein R.sup.2 and R.sup.3 each represents a hydrogen atom, an alkyl group, or R.sup.2 and R.sup.3 may be connected to each other to form a nitrogen containing ring;

• X represents ##STR150## R.sup.1 represents a hydrogen atom, an alkyl group, an alkoxyalkyl group, an aryloxyalkyl group, a dialkylaminoalkyl group, an arylaminoalkyl group, an alkoxy group, an alkoxyalkoxy group, an arylalkoxy group, an aryl group, a halogen atom or a group of ##STR151## D.sup.2 represents an aromatic group which does not contain an ionic group;
• U.sup.1 and U.sup.2 each represents a hydrogen atom, a halogen atom, a methyl group, a methoxy group or an ethoxy group;
• Y.sup.1 represents --O-- or ##STR152## R represents an alkyl group or may be connected to Z.sup.10 to Z.sup.12 to form a ring;
• Z.sup.1 to Z.sup.3 each represents a hydrogen atom, a halogen atom, a methyl group, a hydroxy group, a methoxy group, a cyano group, or Z.sup.1, Z.sup.2 or Z.sup.3 may be connected to R.sup.2 or R.sup.3 to form a nitrogen containing ring;
• Z.sup.4 to Z.sup.12 each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acylamino group or a cyano group, or Z.sup.1 and Z.sup.2, Z.sup.4 and Z.sup.5, Z.sup.7 and Z.sup.8, and Z.sup.10 and Z.sup.11 may be connected to each other to form an aromatic ring;
• and
• n represents 0, 1 or 2;
• with the proviso that at least one of (Z.sup.1 and Z.sup.2), (Z.sup.4 and Z.sup.5), and (Z.sup.7 and Z.sup.8) is connected to each other to form an aromatic ring when R.sup.1 is not a group of ##STR153## and that the dye does not contain a cyclohexyl group.