Claims
- 1. A method of installing a shaped membrane in an electrolytic cell over an electrode wherein the material of the membrane consists of a fluorinated polymer containing active cation exchange groups of the formula: --(COO).sub.m X, wherein X is an alkali metal atom or --NHRR'R", wherein R, R' and R" independently represent hydrogen or lower alkyl and m is the valence of X, comprising:
- installing said membrane in said cell as a fluorinated polymer containing carboxyl groups of the formula: --COOL, wherein L is hydrogen or C.sub.1 -C.sub.20 alkyl over said electrode; and converting the carboxyl groups of the formula: COOL of said membrane into carboxyl groups of the formula:--(COO).sub.m X by passing an aqueous solution of an alkali metal hydroxide into a cathode compartment of said cell and passing an aqueous solution of an alkali chloride into an anode compartment of said cell.
- 2. A method of installing a shaped membrane between a given pair of electrodes in a finger type electrolytic cell having an electrode structure of an electrode of one polarity positioned between the electrodes of the opposite polarity, said membrane being utilized as a cation exchange membrane consisting of a fluorinated polymer having ion exchange groups of the formula: --(COO).sub.m X, wherein X is an alkali metal atom or --NHRR'R", wherein R, R' and R" independently represent hydrogen or lower alkyl, and m is the valence of X, comprising:
- installing said membrane in said cell as a fluorinated polymer containing carboxyl groups of the formula: --COOL, wherein L is hydrogen or C.sub.1 --C.sub.20 alkyl over all electrodes in said cell of the same polarity; and
- converting the carboxyl groups of the formula: --COOL of said membrane into carboxyl groups of the formula: --(COO).sub.m X, by passing an aqueous solution of an alkali metal hydroxide into a cathode compartment of said cell and passing an aqueous solution of an alkali chloride into an anode compartment of said cell.
- 3. The method of claim 1 or 2 wherein said aqueous solution of an alkali metal chloride in said anode compartment is acidic.
- 4. The method of claim 1 or 2, wherein the ion exchange capacity of said carboxylic acid groups of said cation exchange membrane is within the range of 0.8 to 2.0 meq/g of dry polymer.
- 5. The method of claim 1 or 2, wherein said cation exchange membrane is formed of a fluorinated polymer prepared from monomer units of the formula: ##STR3## wherein X represents a fluorine, chlorine or hydrogen atom or --CF.sub.3 ; X' represents X or CF.sub.3 (CF.sub.2)--.sub.m ; m represents an integer from 1 to 5; Y represents a unit selected from the group consisting of: ##STR4## wherein x, y and z each represent an integer from 1 to 10; Z and Rf each represent --F or a C.sub.1 --C.sub.10 perfluoroalkyl group; and A represents a functional group which is convertible during electrolysis into a group of the formula --(COO).sub.m X as defined in Claim 1.
- 6. The method of claim 1 or 2, wherein said cation exchange membrane is a perfluoropolymer.
- 7. The method of claim 1 or 2, wherein said membrane is of a thickness ranging from 20 to 600 microns.
- 8. The method of claim 7; wherein said membrane is of a thickness ranging from 50 to 400 microns.
- 9. The method of claim 1 or 2, wherein said carboxyl group of the formula: --COOL is converted into the cation exchange form by treatment of the membrane with an aqueous solution of an alkali metal hydroxide at a concentration of 3 to 40 wt. % at a temperature of 5.degree. C. to 120.degree. over a period of 1 to 100 hours.
- 10. The method of claim 5, wherein the amount of units (N) in said fluorinated polymer ranges from 1 to 40 mole percent.
Priority Claims (1)
Number |
Date |
Country |
Kind |
55-93866 |
Jul 1980 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 279,752, filed July 2, 1981 now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2013242 |
Aug 1979 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
279752 |
Jul 1981 |
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