An azo compound represented by the following formula (1) or a salt thereof, Wherein A.sup.1 represents a naphthyl group which may have a substituent; A.sup.2, A.sup.3, and A.sup.4 each independently represent a phenyl group which may have a substituent or a naphthyl group which may have a substituent; R.sup.1 represents a hydrogen atom, a hydroxy group, a C1-4 alkoxy group, or a substituted or unsubstituted amino group; m represents an integer of 0 to 5; M represents a hydrogen atom or ion, a metal ion, or an ammonium ion; n represents 1 or 2; k represents 0 or 1; and each hydrogen atom on ring a and ring b may be substituted with the substituent R.sup.1 or substituent SO.sub.3M.

##STR00001##

An azo compound represented by the following formula (1) or a salt thereof, Wherein A.sup.1 represents a naphthyl group which may have a substituent; A.sup.2, A.sup.3, and A.sup.4 each independently represent a phenyl group which may have a substituent or a naphthyl group which may have a substituent; R.sup.1 represents a hydrogen atom, a hydroxy group, a C1-4 alkoxy group, or a substituted or unsubstituted amino group; m represents an integer of 0 to 5; M represents a hydrogen atom or ion, a metal ion, or an ammonium ion; n represents 1 or 2; k represents 0 or 1; and each hydrogen atom on ring a and ring b may be substituted with the substituent R.sup.1 or substituent SO.sub.3M.

##STR00001##

Dichroic azo-azomethine dyes of formula (A) or (B), wherein Ar.sup.1 to Ar.sup.10 are specific (hetero)aromatic moieties and L is a linking group, as defined in the present claims, a dichroic dye mixture comprising said azo-azomethine dyes and a process for preparing the dyes are provided. The dyes are well suited for combination with liquid crystal material for use, inter alia, in a light absorption anisotropic element, for example, in a switchable optical device or an optically anisotropic film.

##STR00001##

Dichroic azo-azomethine dyes of formula (A) or (B), wherein Ar.sup.1 to Ar.sup.10 are specific (hetero)aromatic moieties and L is a linking group, as defined in the present claims, a dichroic dye mixture comprising said azo-azomethine dyes and a process for preparing the dyes are provided. The dyes are well suited for combination with liquid crystal material for use, inter alia, in a light absorption anisotropic element, for example, in a switchable optical device or an optically anisotropic film.

##STR00001##

An ink set includes a magenta ink composition; a cyan ink composition; a yellow ink composition; and a black ink composition, in which the magenta ink composition contains at least one compound represented by the general formula (1) as defined herein, the cyan ink composition contains at least one compound represented by the general formula (2) as defined herein, the yellow ink composition contains at least one compound selected from the group Y as defined herein, and the black ink composition contains at least one compound selected from the group BK as defined herein.

An ink set includes a magenta ink composition; a cyan ink composition; a yellow ink composition; and a black ink composition, in which the magenta ink composition contains at least one compound represented by the general formula (1) as defined herein, the cyan ink composition contains at least one compound represented by the general formula (2) as defined herein, the yellow ink composition contains at least one compound selected from the group Y as defined herein, and the black ink composition contains at least one compound selected from the group BK as defined herein.

A coloring composition containing one or more species of compounds represented by Formula (I) or Formula (II) below, wherein each of R.sub.1 and R.sub.2 represents a hydrogen atom or substituent, each of Ar.sub.1 to Ar.sub.8 independently represents an optionally substituted aromatic hydrocarbon group or optionally substituted heterocyclic group, and each of L.sub.1 and L.sub.2 independently represents a divalent linking group which interrupts ? electron conjugated system: ##STR00001##

A coloring composition containing one or more species of compounds represented by Formula (I) or Formula (II) below, wherein each of R.sub.1 and R.sub.2 represents a hydrogen atom or substituent, each of Ar.sub.1 to Ar.sub.8 independently represents an optionally substituted aromatic hydrocarbon group or optionally substituted heterocyclic group, and each of L.sub.1 and L.sub.2 independently represents a divalent linking group which interrupts ? electron conjugated system: ##STR00001##

The present invention relates to an azo compound that is useful as a dichroic pigment used in a polarizing plate having excellent polarizing performance and durability and having little color leakage in a visible light region, and used in a neutral gray polarizing plate for vehicle mounting that uses the aforementioned polarizing plate. More specifically, the invention relates to an azo compound that is represented by formula (1) [In the formula, R.sub.1-R.sub.4 each independently represent a hydrogen atom, a C1-5 alkyl group, a C1-5 alkoxy group, a sulfo group, or a C1-5 alkoxy group having a sulfo group, X represents an amino group having a substituent, a benzoylamino group having a substituent, a phenylamino group having a substituent, a phenylazo group having a substituent, or a naphthotriazole group having a substituent, m represents 3 or 4, n represents 1 or 2, and p represents 1, 2, or 3.], or to a salt of said compound.

The present invention relates to an azo compound that is useful as a dichroic pigment used in a polarizing plate having excellent polarizing performance and durability and having little color leakage in a visible light region, and used in a neutral gray polarizing plate for vehicle mounting that uses the aforementioned polarizing plate. More specifically, the invention relates to an azo compound that is represented by formula (1) [In the formula, R.sub.1-R.sub.4 each independently represent a hydrogen atom, a C1-5 alkyl group, a C1-5 alkoxy group, a sulfo group, or a C1-5 alkoxy group having a sulfo group, X represents an amino group having a substituent, a benzoylamino group having a substituent, a phenylamino group having a substituent, a phenylazo group having a substituent, or a naphthotriazole group having a substituent, m represents 3 or 4, n represents 1 or 2, and p represents 1, 2, or 3.], or to a salt of said compound.