The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 05, 1981
Filed:
Oct. 23, 1979
Stanley K Baczek, Painesville, OH (US);
G Howard McCain, Painesville, OH (US);
Diamond Shamrock Corporation, Dallas, TX (US);
Abstract
Normally solid copolymers of a fluorinated vinyl monomer and a perfluorinated vinyl compound having a carboxyl and/or sulfonyl group attached directly to the perfluorinated vinyl group or indirectly through an alkyl or ether linkage have been found to be soluble in low molecular weight polymers of perhalogenated alkyl ethers, low molecular weight polymers of perhalogenated alkyls and perfluoro kerosenes, each of said solvent materials having boiling points between about 200.degree. C. and 350.degree. C. The copolymeric material dissolved in accordance with the instant invention can readily be resolidified by solvent removal and hydrolyzed or converted to the salt form to become a cation exchange material having an equivalent weight in the range of 1000 to 1600. When these cation exchange materials in the salt form become damaged or contaminated during operation, for example in an electrochemical cell, they may now be reclaimed rather than discarded. The process involves conversion of the salt form of the cation exchanger to the precursor sulfonyl fluoride, carbonyl fluoride, sulfonate ester, or carboxylate ester form followed by dissolution in one of the solvents mentioned above. Dissolved impurities are then removed, e.g., by filtration, and the purified precursor cation exchange material in dissolved state may be shaped into the desired form by solvent removal and hydrolyzed back to the purified cation exchange polymeric material.