Patent ID: 8491823

Claim:
A process for producing a water-resistant polarizing film comprising the step of performing water-resistant treatment by bringing a liquid including a divalent cation into contact with at least one surface of a polarizing film including an organic dye having at least two sulfonic acid groups or sulfonate groups, wherein the organic dye before the water-resistant treatment is an azo compound represented by the following general formula (1): wherein Q1 is an aryl group which has a substituent group; R is a hydrogen atom, an alkyl group having 1 to 3 carbon numbers, an acetyl group, a benzoyl group, or a phenyl group which has a substituent group; m is an integer from 0 to 5, n is an integer from 0 to 5 in which m+n≦5, and at least one of m and n is not 0; and M represents an element to provide a monovalent cation.