Back to results
US 4,284,460 AGranted
Heat sealing untreated sulfonamide-type cation exchange membranes
AssigneeOlin Corporation
InventorsSanders H. Moore, John O. Adams
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeOlin Corporation
InventorsSanders H. Moore, John O. Adams
Estimating the term…
A method of heat sealing together two untreated layers of a sulfonated perfluorovinyl ether ion exchange diaphragm or membrane material having pendant groups predominantly in the sulfonamide form by placing a layer of untreated sulfonated perfluorovinyl ether material having pendant groups predominantly in the sulfonic acid form between the sulfonamide layers to create a "sandwich". The preferred heat sealing involves applying from 1 to 5, and preferably from 3.5 to 5.0 kg/cm.sup.2 pressure at from 260.degree. to 350.degree. C. and preferably from 280.degree. to 320.degree. C. for from 3.5 to 7.5, and preferably from 3.5 to 5.0 seconds to this "sandwich". It had been previously taught that such untreated sulfonamide layers could not be heat sealed together. The novel heat sealing technique of this invention enables fabrication of a cathode-membrane unit using ion exchange membranes having such a sulfonamide layer facing the cathode of an electrolytic cell.
A method of joining two sheets of a cation exchange material, which material has not been treated with either a tertiary amine or a quaternary ammonium base or the salt of either said amine or said base, each of said sheets having a first side, which first side has an external layer of a sulfonated perfluorovinyl ether polymer having pendant sulfonamide cation exchange groups, which consists essentially of the steps of:
The method of claim 2 wherein said time is within the range of from about 3.5 to about 5.0 seconds.
Dependencies are inferred from the claim text.