Multilayer cation exchange chlor-alkali membrane

The invention relates to a multi-layer cation exchange chlor-alkali membrane. The invention provides a multi-layer cation exchange membrane used in a chlor-alkali method. The multi-layer cation exchange membrane comprises a carboxylate layer comprising a fluorinated ionomer comprising carboxylate groups on one side of the membrane, an outer sulfonate layer comprising a fluorinated ionomer comprising sulfonate groups on the side of the membrane opposite the carboxylate layer, and an inner sulfonate layer comprising a fluorinated ionomer containing sulfonate groups between the carboxylate layer and the outer sulfonate layer, the outer sulfonate layer having an ion exchange rate of greater than about 11.3, and the inner sulfonate layer having an ion exchange rate of less than about 11. 本申请涉及多层阳离子交换氯碱膜。本发明提供了一种在氯碱法中使用的多层阳离子交换膜，所述多层阳离子交换膜包括位于所述膜的一侧上的包含含有羧酸根基团的氟化离聚物的羧酸盐层、位于所述膜的与所述羧酸盐层相对的侧上的包含含有磺酸根基团的氟化离聚物的外部磺酸盐层、以及位于所述羧酸盐层与所述外部磺酸盐层之间的包含含有磺酸根基团的氟化离聚物的内部磺酸盐层，所述外部磺酸盐层具有大于约11.3的离子交换率，并且所述内部磺酸盐层具有小于约11的离子交换率。