Production method for ion exchange membrane for alkali chloride electrolysis, and production method for alkali chloride electrolysis apparatus

A production method for an ion exchange membrane for alkali chloride electrolysis, which is a method for producing an ion exchange membrane for alkali chloride electrolysis having a layer containing a fluorinated polymer having carboxylic acid type functional groups, by immersing an ion exchange membrane precursor film having a precursor layer containing a fluorinated polymer having groups convertible to carboxylic acid type functional groups, in an alkaline aqueous solution containing an alkali metal hydroxide, a water-soluble organic solvent and water, and subjecting the groups convertible to carboxylic acid type functional groups to hydrolysis treatment to convert them to carboxylic acid type functional groups, wherein

• the proportion of structural units having the carboxylic acid type functional groups in the fluorinated polymer having the carboxylic acid type functional groups, is from 13.10 to 14.50 mol %, in all structural units (100 mol %) in the fluorinated polymer having the carboxylic acid type functional groups,
• in the layer containing a fluorinated polymer having carboxylic acid type functional groups, the following value of resistivity is from 4.0×103 to 25.0×103 Ω·cm, and the following variation in resistivity is at most 4.0×103 Ω·cm, and
• the concentration of the water-soluble organic solvent is from 1 to 60 mass % in the alkaline aqueous solution (100 mass %):
• Value of resistivity and variation in resistivity:
• Five points in the ion exchange membrane for alkali chloride electrolysis are randomly selected;
• at the respective points, the resistivity in the layer containing a fluorinated polymer having carboxylic acid type functional groups is measured;
• and the average value of the resistivity at the 5 points in the ion exchange membrane for alkali chloride electrolysis is taken as the value of the resistivity, and further, the value twice the standard deviation in the resistivity at the 5 points in the ion exchange membrane for alkali chloride electrolysis is taken as the variation in the resistivity.