Polarizer and image display device

A polarizer comprising:

• a composition for forming a polarizer which contains a polymer liquid crystal compound and a dichroic material,
• wherein the dichroic material includes a first dichroic material and a second dichroic material,
• an absolute value of a difference between a log P value of the first dichroic material and a log P value of the second dichroic material is 1.0 or less,
• a stabilization energy in a case where one dichroic material of the first dichroic material or the second dichroic material is incorporated into a structure formed of the other dichroic material of the first dichroic material or the second dichroic material is 30 kcal/mol or less, and
• the second dichroic material is a compound represented by Formula (2):
• in Formula (2), n represents 1 or 2,
• in Formula (2), Ar3, Ar4, and Ar5 each independently represent 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,
• in Formula (2), R4 represents a hydrogen atom, an alkyl group, 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, which may have a substituent,
• in Formula (2), R5 and R6 each independently represent a hydrogen atom, an alkyl group, 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, which may have a substituent, and R5 and R6 may be bonded to each other to form a ring, and R5 or R6 may be bonded to Ar5 to form a ring.