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:
Nov. 13, 1990
Filed:
Dec. 15, 1986
Asahi Glass Company, Ltd., Tokyo, JP;
Abstract
A method for producing an alkali metal hydroxide by electrolysis in an electrolytic cell comprising an anode compartment and a cathode compartment, which comprises supplying an alkali metal chloride to the anode compartment and water or a dilute alkali metal hydroxide to the cathode compartment, wherein a fluorine-containing cation exchange membrane comprising a first outer layer of a perfluorocarbon polymer having --SO.sub.3 M groups (wherein M is an alkali metal) with a thickness of at least 5 .mu.m, and a second layer of a perfluorocarbon polymer having --CO.sub.2 M groups (wherein M is an alkali metal) and a water content of from 2 to 7% by weight in a 45% wt % NaOH aqueous solution with a thickness of at least 5 .mu.m, the water content of the first layer being higher than that of the second layer, is disposed with the first layer facing the cathode compartment.