IMPROVED PROCESS FOR FUSION BONDING OF FLUOROCARBON TYPE POLYMERS

摘要

A fluorinated polymer having pendant cation exchange groups selected from sulfonic acid, carboxylic acid or sulfonamide groups, or their salts, is modified with a sulfonium compound and/or a phosphonium compound for substitution of the counter-ions of the cation exchange groups with sulfonium ions and/or phosphonium ions. The polymers treated in this manner are improved in their melt-flow characteristic to make fusion bonding between these polymers possible. The process is particularly suitable for repairing damaged cation exchange membranes for use in chlor-alkali electrolytic cells to advantageously elongate the life of the membranes.