PURPOSE: To reclaim the polymers respectively by a simple economical process, by converting the ion exchange groups in each polymer layer of a specified double-layer F-containing ion exchange membrane into an acid form or an alkali metal salt form and dissolving the polymers in respective solvents by immersion.
CONSTITUTION: Two F-containing monomers are polymerized with each other to obtain a double-layer F-containing ion exchange membrane comprising at least two F- containing polymer layers having polymer units of formulas I and II [wherein X and X' are each F, Cl, H or CF3, A is SO3M or COOM (wherein M is Na or K), Y is a group of formula III or IV (wherein Z is F or a 1W10C perfluoroalkyl and x is 1W10)] and having an ion exchange capacity ≥0.8meq/g dry resin (for COOM) or an ion exchange capacity ≥0.6meq/g dry resin (for SO3M). In the reclamation of this ion exchange membrane, the ion exchange groups in each polymer layer of this membrane are converted into an acid form or an alkali metal salt form and the membrane is immersed in a water-soluble organic solvent (e.g., acetone) to cause delamination. Each layer is dissolved by immersion in a highly polar water-soluble organic solvent, recovered and resolidified into a desired form.
SUGAYA YOSHIO
YAMADA RYOJI
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