Polarizer and image display device

A polarizer which is formed of a polarizer-forming composition containing a liquid crystal compound, a first dichroic material comprising one or more molecules, and a second dichroic material that is different from the first dichroic material, comprising one or more molecules,

• wherein the first dichroic material is a compound represented by Formula (1),
• the second dichroic material is a compound represented by Formula (2), and
• when a sum of an energy in a state in which one molecule of the first dichroic material in a super cell of the first dichroic material is replaced with one molecule of the second dichroic material, and an energy of one molecule of the first dichroic material, is set to X1, and
• when a sum of an energy of a super cell formed of only the first dichroic material before one molecule of the first dichroic material in the super cell is replaced with one molecule of the second dichroic material, and an energy of one molecule of the second dichroic material, is set to X2,
• a stabilization energy ratio, which is a ratio of the X1 to the X2, is 0.22 to 1.50,
• in Formula (1),
• Ar1 and Ar2 each independently represent a phenylene group which may have a substituent or a naphthylene group which may have a substituent,
• R1 represents a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group, an alkylthio group, an alkylsulfonyl group, an alkylcarbonyl group, an alkyloxycarbonyl group, an acyloxy group, an alkylcarbonate group, an alkylamino group, an acylamino group, an alkylcarbonylamino group, an alkoxycarbonylamino group, an alkylsulfonylamino group, an alkylsulfamoyl group, an alkylcarbamoyl group, an alkylsulfinyl group, an alkylureido group, an alkylphosphoric acid amide group, an alkylimino group, or an alkylsilyl group,
• R2 and R3 each independently represent a linear or branched alkyl group having 1 to 20 carbo atoms which may be substituted with an acryloyloxy group,
• in Formula (2),
• n represents 1 or 2,
• Ar3, and Ar4 each independently represent a phenylene group which may have a substituent,
• Ar5 represents a phenylene group which may have a substituent, a naphthylene group which may have a substituent, or a heterocyclic group which may have a substituent,
• R4 represents a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group, an alkylthio group, an alkylsulfonyl group, an alkylcarbonyl group, an alkyloxycarbonyl group, an acyloxy group, an alkylcarbonate group, an alkylamino group, an acylamino group, an alkylcarbonylamino group, an alkoxycarbonylamino group, an alkylsulfonylamino group, an alkylsulfamoyl group, an alkylcarbamoyl group, an alkylsulfinyl group, an alkylureido group, an alkylphosphoric acid amide group, an alkylimino group, or an alkylsilyl group,
• R5 and R6 each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group, an alkoxy group, an acyl group, an alkyloxycarbonyl group, an alkylamide group, an alkylsulfonyl group, an aryl group, an arylcarbonyl group, an arylsulfonyl group, an aryloxycarbonyl group, or an arylamide group, R5 and R6 may be bonded to each other to form a ring,
• when R4 represents an alkyl group, at least one carbon atom of the alkyl group in R4 is substituted with —O—, —CO—, —C(O)—O—, —O—C(O)—, —Si(CH3)2—O—Si(CH3)2—, —N(R1′)—, —N(R1′)—CO—, —CO—N(R1′)—, —N(R1′)—C(O)—O—, —O—C(O)—N(R1′)—, —N(R1′)—C(O)—N(R1′)—, —CH═CH—, —C≡C—, —N═N—, —C(R1′)=CH—C(O)—, or —O—C(O)—O, R1′ represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and when a plurality of (R1′)'s are present in each group, these may be the same as or different from one another.