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:
Jan. 04, 1983
Filed:
Mar. 21, 1979
Applicant:
Inventors:
Assignee:
Toyo Soda Manufacturing Co., Ltd., Yamaguchi, JP;
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
210636 ; 210638 ; 210639 ; 2041 / ;
Abstract
Characteristics of a cation exchange membrane used for an electrolysis of an alkali metal chloride are recovered by immersing the perfluorocarbon type cation exchange membrane in an organic solvent having a water miscibility and a boiling point of higher than 120.degree. C. in 760 mmHg; holding the immersed membrane between a pair of smooth plates and heating at 40.degree. C. to 180.degree. C.; treating the heat-treated membrane in hydrochloric acid and then, immersing it in an aqueous solution of sodium hydroxide and the organic solvent is preferably ethyleneglycol, propyleneglycol, isopropyleneglycol butanediol, pentanediol, hexanediol, glycerin or polyethyleneglycol.