US4151053A
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Cation exchange membrane preparation and use thereof
Assignee: Asahi Kasei Corp
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Filing: 1978-03-17
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Granted: 1979-04-24
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Expires: 1998-03-17
Abstract
Abstract Cation exchange membrane comprising a fluorocarbon polymer characterized by the presence of pendant carboxylic acid groups of the formula -- OCF 2 COOH -- and derivatives thereof.
Inventors
- 👤 Naomi Seko
- 👤 Yasumichi Yamakoshi
- 👤 Hirotsugu Miyauchi
- 👤 Mitsunobu Fukumoto
- 👤 Kyoji Kimoto
- 👤 Itaru Watanabe
- 👤 Toshioki Hane
- 👤 Sakae Tsushima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:44
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/12; C08J5/00; C08J5/20; C08J5/22; C08J5/2287; C08J5/2293; C25; C25B; C25B1/00; C25B1/01; C25B1/34; C25B1/46; C08J2327/00; C08J2327/02; C08J2327/12
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
40 words
A cation exchange membrane comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups of the formula --OCF 2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms.
Claim 2
Dependent Claim
40 words
A cation exchange membrane comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups of the formula --OCF 2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms.
Claim 3
Dependent Claim
28 words
A cation exchange membrane as in claim 1, wherein the fluorocarbon polymer further contains pendant sulfonic acid or salt groups represented by the formula: --OCF.sub.2 CF.sub.2 SO.sub.3 M.
Claim 4
Dependent Claim
67 words
a cation exchange membrane as in claim 1, comprising (a) at least one stratum at least 100 A in thickness of a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups of the formula --OCF 2 COOM and (b) a fluorocarbon polymer having cation exchange groups substantially consisting of sulfonic acid or salt groups of the formula --OCF 2 CF 2 SO 3 M.
Claim 5
Dependent Claim
33 words
A cation exchange membrane as in claim 3, wherein the fluorocarbon polymer of stratum (a) further contains pendant sulfonic acid or salt groups of the formula --OCF 2 CF 2 SO 3 M.
Claim 6
Dependent Claim
23 words
A cation exchange membrane as in claim 3, wherein the fluorocarbon polymer (a) is a surface stratum on one surface of the membrane.
Claim 7
Dependent Claim
30 words
A cation exchange membrane as in claim 1, substantially consisting of the fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups of the formula --OCF 2 COOM.
Claim 8
Dependent Claim
31 words
A cation exchange membrane as in claim 1, wherein at least 20 mol percent of the ion exchange groups contained as pendant groups of the fluorocarbon polymer are --OCF 2 COOM.
Claim 9
Dependent Claim
22 words
The cation exchange membrane of claim 1 reinforced with a material selected from the group consisting of woven fabrics of inert fibers.
Claim 10
Dependent Claim
13 words
The cation exchange membrane of claim 8 wherein the inert fibers are polytetrafluoroethylene.
Claim 11
Dependent Claim
137 words
A cation exchange membrane comprising two bonded polymer films, a first film comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups represented by the formula: --OCF.sub.2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms; and a second film comprising a fluorocarbon polymer containing pendant sulfonic acid or salt groups represented by the formula: --OCF.sub.2 CF.sub.2 SO.sub.3 M wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms; the equivalent weight of the polymer in each film being from 1000 to 2000; the equivalent weight of the polymer in the first film being at least 150 higher than the polymer in the second film; the thickness of the first film being up to 50% of the total thickness.
Claim 12
Dependent Claim
137 words
A cation exchange membrane comprising two bonded polymer films, a first film comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups represented by the formula: --OCF.sub.2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms; and a second film comprising a fluorocarbon polymer containing pendant sulfonic acid or salt groups represented by the formula: --OCF.sub.2 CF.sub.2 SO.sub.3 M wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms; the equivalent weight of the polymer in each film being from 1000 to 2000; the equivalent weight of the polymer in the first film being at least 150 higher than the polymer in the second film; the thickness of the first film being up to 50% of the total thickness.
Claim 13
Dependent Claim
32 words
A cation exchange membrane as in claim 10, wherein the fluorocarbon polymer in the first film further contains pendant sulfonic acid or salt groups represented by the formula: --OCF.sub.2 CF.sub.2 SO.sub.3 M.
Claim 14
Dependent Claim
92 words
a cation exchange membrane as in claim 10, wherein the first film comprises (a) a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups of the formula --OCF 2 COOM and (b) a fluorocarbon polymer having cation exchange groups substantially consisting of sulfonic acid or salt groups of the formula --OCF 2 CF 2 SO 3 M, said fluorocarbon polymer (a) existing as at least one layer in a thickness of each of at least 100 A on the surface or in the internal portion of the first film.
Claim 15
Dependent Claim
31 words
A cation exchange membrane as in claim 12, wherein the fluorocarbon polymer (a) further contains pendant sulfonic acid or salt groups of the formula --OCF 2 CF 2 SO 3 M.
Claim 16
Dependent Claim
32 words
A cation exchange membrane as in claim 12, wherein the fluorocarbon polymer (a) is present as a surface stratum at least about 100 A in thickness on one surface of the membrane.
Claim 17
Dependent Claim
34 words
A cation exchange membrane as in claim 10, wherein the first film substantially consists of the fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups of the formula --OCF 2 COOM.
Claim 18
Dependent Claim
35 words
A cation exchange membrane as in claim 10, wherein at least 20 mol percent of the ion exchange groups contained as pendant groups of the fluorocarbon polymer in the first film are --OCF 2 COOM.
Claim 19
Dependent Claim
22 words
The cation exchange membrane of claim 10, reinforced with a material selected from the group consisting of woven fabrics of inert fibers.
Claim 20
Dependent Claim
13 words
The cation exchange membrane of claim 17, wherein the inert fibers are polytetrafluoroethylene.
Claim 21
Dependent Claim
17 words
The cation exchange membrane of claim 17, wherein the reinforcing material is embedded in the second film.
Claim 22
Independent Claim
114 words
A method for the production of a cation exchange membrane comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups represented by the formula: --OCF.sub.2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms, which method comprises treating with a reducing agent a membrane comprising a corresponding fluorocarbon polymer characterized by the presence of sulfonyl groups represented by the formula: ##STR7## wherein X is selected from the group consisting of halogen; hydroxyl; alkyl containing up to four carbon atoms; aryl; and OZ wherein Z is selected from the group consisting of metallic atoms, alkyl containing up to four carbon atoms and aryl.
Claim 23
Independent Claim
114 words
A method for the production of a cation exchange membrane comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups represented by the formula: --OCF.sub.2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms, which method comprises treating with a reducing agent a membrane comprising a corresponding fluorocarbon polymer characterized by the presence of sulfonyl groups represented by the formula: ##STR7## wherein X is selected from the group consisting of halogen; hydroxyl; alkyl containing up to four carbon atoms; aryl; and OZ wherein Z is selected from the group consisting of metallic atoms, alkyl containing up to four carbon atoms and aryl.
Claim 24
Dependent Claim
10 words
A method as in claim 20 wherein X is chlorine.
Claim 25
Dependent Claim
21 words
A method as in claim 20 in which the sulfonyl groups are initially converted to sulfinic acid groups or salts thereof.
Claim 26
Dependent Claim
33 words
A method as in claim 22 wherein the initially formed membrane is further treated with a reducing agent to convert the sulfinic acid groups or salts thereof to carboxylic acid or salt groups.
Claim 27
Dependent Claim
41 words
A method as in claim 22 wherein the initially formed membrane is heated at from 60° C. to 400° C. for from 15 to 120 minutes to convert the sulfinic acid groups or salts thereof to carboxylic acid or salt groups.
Claim 28
Dependent Claim
45 words
A method as in claim 20, wherein the reducing agent is at least one selected from the group consisting of: (1) inorganic acids possessing reducing activity; (2) mixtures of metals and acids; (3) low-valency metal compounds; and (4) salts of inorganic acids possessing reducing activity.
Claim 29
Dependent Claim
84 words
A method as in claim 20, wherein the starting membrane comprises two bonded films, each film containing sulfonyl groups represented by the formula: ##STR8## the equivalent weight in each film being from 1000 to 2000; the equivalent weight of the polymer in the first film being at least 150 higher than the polymer in the second film; and the thickness of the first film being up to 50% of the total thickness, said treatment with a reducing agent being applied onto the first film.
Claim 30
Dependent Claim
26 words
A method as in claim 20, wherein the starting membrane is reinforced with a material selected from the group consisting of woven fabrics of inert fibers.
Claim 31
Dependent Claim
22 words
A method as in claim 27, wherein treatment with a reducing agent is applied onto the side opposite to the reinforced side.
Claim 32
Dependent Claim
30 words
A method as in claim 26, wherein the second film in the starting membrane is reinforced with a material selected from the group consisting of woven fabrics of inert fibers.
Claim 33
Dependent Claim
51 words
An electrolytic cell comprising an anode portion and a cathode portion separated by a membrane comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups represented by the formula: --OCF.sub.2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms.
Claim 34
Dependent Claim
51 words
An electrolytic cell comprising an anode portion and a cathode portion separated by a membrane comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups represented by the formula: --OCF.sub.2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms.
Claim 35
Dependent Claim
86 words
An electrolytic cell comprising an anode portion and a cathode portion separated by a membrane comprising (a) a surface stratum at least 100 A in thickness of a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups of the formula --OCF 2 COOM and (b) a fluorocarbon polymer having cation exchange groups substantially consisting of sulfonic acid or salt groups of the formula --OCF 2 CF 2 SO 3 M, said surface stratum of the membrane facing the cathode side of the cell.
Claim 36
Dependent Claim
86 words
An electrolytic cell comprising an anode portion and a cathode portion separated by a membrane comprising (a) a surface stratum at least 100 A in thickness of a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups of the formula --OCF 2 COOM and (b) a fluorocarbon polymer having cation exchange groups substantially consisting of sulfonic acid or salt groups of the formula --OCF 2 CF 2 SO 3 M, said surface stratum of the membrane facing the cathode side of the cell.
Claim 37
Dependent Claim
161 words
An electrolytic cell comprising an anode portion and a cathode portion separated by a membrane comprising two bonded polymer films, a first film comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups represented by the formula: --OCF.sub.2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms; and a second film comprising a fluorocarbon polymer containing pendant sulfonic acid or salt groups represented by the formula: --OCF.sub.2 CF.sub.2 SO.sub.3 M wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms; the equivalent weight of the polymer in each film being from 1000 to 2000; the equivalent weight of the polymer in the first film being at least 150 higher than the polymer in the second film; the thickness of the first film being up to 50% of the total thickness, the side of said first film facing the cathode side of the cell.
Claim 38
Dependent Claim
161 words
An electrolytic cell comprising an anode portion and a cathode portion separated by a membrane comprising two bonded polymer films, a first film comprising a fluorocarbon polymer containing a plurality of pendant carboxylic acid or salt groups represented by the formula: --OCF.sub.2 COOM wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms; and a second film comprising a fluorocarbon polymer containing pendant sulfonic acid or salt groups represented by the formula: --OCF.sub.2 CF.sub.2 SO.sub.3 M wherein M is selected from the group consisting of hydrogen; ammonium; quaternary ammonium; and metallic atoms; the equivalent weight of the polymer in each film being from 1000 to 2000; the equivalent weight of the polymer in the first film being at least 150 higher than the polymer in the second film; the thickness of the first film being up to 50% of the total thickness, the side of said first film facing the cathode side of the cell.
Claim 39
Dependent Claim
36 words
In a method for the electrolysis of an aqueous solution of an alkali metal halide for the production of the corresponding halogen and alkali metal hydroxide, the improvement comprising utilizing the electrolytic cell of claim 30.
Claim 40
Dependent Claim
14 words
A method as in claim 33, wherein the alkali metal halide is sodium chloride.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-23 | 1982-10-23 | 1983-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-23 | 1986-10-23 | 1987-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-23 | 1990-10-23 | 1991-04-24 | $7700.00 | Window Closed / Lapsed |