Method for producing an alkali metal hydroxide
US5039382A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1989 |
| Grant date | Aug 13, 1991 |
| Priority date | — |
| Expiry date | Feb 3, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2371/12
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
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 aqueous alkali metal chloride solution to the anode compartment and withdrawing an aqueous alkali metal hydroxide solution from the cathode compartment, wherein a fluorine-containing cation exchange membrane comprising a first layer of an alkali resistant cation exchanger with a thickness of at least 5 .mu.m selected from the group consisting of the following (a), (b), and (c), 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 thicknesss of at least 5 .mu.m, is disposed with the first layer facing the cathode compartment; PA1 (a) a layer of a cation exchanger having alkali resistant inorganic particles or fibrils dispersed therein, PA1 (b) a layer of porous material of a cation exchange resin with minimum permability, and PA1 (c) a layer of a cation exchanger having an alkali resistant polymer having no ion exchange groups embedded therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.