Process for producing water-resistant polarizing film
AssigneeNitto Denko Corporation
InventorsJunzo Miyazaki, Shoichi Matsuda, Kyoko Nishiguchi
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Abstract
To obtain a water-resistant polarizing film free from deterioration in dichroic ratio caused by water-resistant treatment, it is critical that adjacent sulfonic acid groups or sulfonate groups in the organic dyes to be used for the polarizing film are spaced at moderate intervals. In a process for producing a water-resistant polarizing film of the present invention, the polarizing film before water-resistant treatment includes an organic dye which comprises an azo compound 20 represented by the following general formula (2)
Claims6
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 (2):
- wherein Q2 is respectively 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;
- k is an integer from 0 to 5;
- l is an integer from 0 to 5 in which k+l≦5 and at least one of k and l is not 0;
- and M represents an element to provide a monovalent cation.
Dependencies are inferred from the claim text.