A compound serving as a dichroic pigment which has a maximum absorption wavelength in a range of 350 nm to 510 nm is represented by the following Formula (1):

##STR00001##

In Formula (1), R.sup.1 represents a hydrogen atom or a C1-C20 alkyl group; R.sup.2 through R.sup.4 are substituents which are not hydrogen atoms and each independently represent a C1-C4 alkyl group; n, m, and p are each independently an integer of 0 to 2; and Ar.sup.1 represents a nitrogen-containing saturated heterocyclic group which is a 5 to 8-membered ring and in which (i) N is bonded to a phenylene group and (ii) at least one -position is an oxygen atom or a sulfur atom.

A composition is provided which contains a compound represented by Formula (1) below and a polymerizable smectic liquid crystal compound:

##STR00001##

In Formula (1), R.sup.1 represents a hydrogen atom or a C1-C20 alkyl group; R.sup.2 through R.sup.4 each independently represent a C1-C4 alkyl group; n, p, and q are each independently an integer of 0 to 2; and R.sup.5 is (i) a nitrogen-containing saturated heterocyclic group which is a 6-membered ring and in which N is bonded to a phenylene group, or (ii) a group in which N is bonded to at least one C1-C10 alkyl group.

The present invention relates to an ink comprising: a solvent having a relative permittivity, measured at a frequency of 1 kHz and a temperature of 22 C., of 3 or less and a solubility in water at 25 C. of 20 mg/L or less; and a specific azo compound.

The present invention relates to an ink comprising: a solvent having a relative permittivity, measured at a frequency of 1 kHz and a temperature of 22 C., of 3 or less and a solubility in water at 25 C. of 20 mg/L or less; and a specific azo compound.