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##

The present invention relates to a composition for forming a dye-type polarizer, which can be used to provide a dye-type polarizer showing excellent degree of polarization, heat resistance and dichroic ratio, and to a dye-type polarizer. The composition for forming a dye-type polarizer includes a curable anisotropic dye having a particular chemical structure; and an orientation auxiliary agent having a predetermined chemical structure.

The present invention relates to a composition for forming a dye-type polarizer, which can be used to provide a dye-type polarizer showing excellent degree of polarization, heat resistance and dichroic ratio, and to a dye-type polarizer. The composition for forming a dye-type polarizer includes a curable anisotropic dye having a particular chemical structure; and an orientation auxiliary agent having a predetermined chemical structure.

Electrowetting apparatus including at least one compound selected from the group consisting of: ##STR00001##
wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is independently an alkyl group. In examples a fluid includes a dye compound selected from: ##STR00002##

Electrowetting apparatus including at least one compound selected from the group consisting of: ##STR00001##
wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is independently an alkyl group. In examples a fluid includes a dye compound selected from: ##STR00002##

The purpose of the present invention is to provide: a high performance dye-based polarizing film and dye-based polarizing plate, in particular a neutral gray high performance dye-based film and dye-based polarizing plate, having excellent polarizing performance and moisture resistance, heat resistance and light resistance; and an azo compound or a salt thereof able to produce same. The present invention provides an azo compound represented by formula (1) or a salt thereof.

##STR00001##

The purpose of the present invention is to provide: a high performance dye-based polarizing film and dye-based polarizing plate, in particular a neutral gray high performance dye-based film and dye-based polarizing plate, having excellent polarizing performance and moisture resistance, heat resistance and light resistance; and an azo compound or a salt thereof able to produce same. The present invention provides an azo compound represented by formula (1) or a salt thereof.

##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##

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##