Method of regenerating electrochemical properties of cation exchange membrane of fluorinated polymer
AssigneeAsahi Glass Company, Limited
InventorsTatsuro Asawa, Tomoki Gunjima
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Abstract
Electrochemical properties of a cation exchange membrane of a carboxylic acid type fluorinated polymer which is used for an electrolysis of an aqueous solution of an alkali metal chloride is recovered by converting ion exchange groups of --COO).sub.m M; wherein M represents an alkali metal or an alkaline earth metal; and m represents a valence of M; to the corresponding acid or ester groups of --COOR wherein R represents hydrogen or a C.sub.1 - C.sub.5 alkyl group and heat-treating the fluorinated polymer having the groups of --COOR.
Claims12
In a method of regenerating the electrochemical properties of cation exchange membrane of a carboxylic acid type fluorinated polymer having ion exchange groups of --COO).sub.m M wherein M represents an alkali metal or an alkaline earth metal;
- and m represents a valence of M, an improvement which comprises converting the ion exchange groups of --COO).sub.m M to the corresponding acid or ester groups of --COOR wherein R represents hydorgen or a C.sub.1 -C.sub.5 alkyl group and heat-treating the fluorinated polymer having said --COOR groups at a temperature greater than that at which said fluorinated polymer has a volumetric melt flow rate of 0.1 mm.sup.3 /sec and below the thermal decomposition temperature of said fluorinated polymer.
Dependencies are inferred from the claim text.