US4470889A
Expired / Lapsed
US
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Electrolytic cell having an improved ion exchange membrane and process for operating
Assignee: Dow Chemical Co
•
Filing: 1980-06-11
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Granted: 1984-09-11
•
Expires: 2000-06-11
Abstract
Abstract An electrolytic cell and a process for electrolysis using the cell are provided. The electrolytic cell is separated into an anode chamber and a cathode chamber by a fluorinated polymer membrane; wherein the membrane comprises: (a) at least 60 mole percent [CFX--CF 2 ] where X=F or Cl; (b) an ion exchange equivalent weight of at least 600; (c) pendant sulfonyl ion exchange groups; and (d) pendant substantially fluorinated carbon groups which have no ion exchange functionality. These cells are particularly useful for the electrolysis of aqueous, alkali metal halides.
Inventors
- 👤 Bobby R. Ezzell
- 👤 William P. Carl
- 👤 William A. Mod
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:05
CPC Classifications
C; C25; C25B; C25B13/00; C25B13/04; C25B13/08; C25B1/00; C25B1/01; C25B1/34; C25B1/46; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; C08J5/2231; C08J5/2237; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
144 words
In an electrolytic cell of the type having an anode in an anode chamber; a cathode in a cathode chamber and an ion exchange membrane separating the anode chamber from the cathode chamber, wherein said membrane is a copolymer of CFXCF 2 , where X is F or Cl, and a fluorinated vinyl ether compound having sulfonyl ion exchange functionality, wherein said copolymer has a polymeric backbone with sulfonyl-containing pendant groups attached thereto; wherein the improvement comprises the copolymer having additional pendant groups attached to the backbone represented by the formula: ##STR11## where X' and X'" are independently selected from the group consisting of F, Cl and Br n', a' and b' are independently zero or an integer greater than zero, provided n'+a'+b'≠0 R f and R f ' are independently selected from the group consisting of fluorine, chlorine, fluoroalkyls and chlorofluoro alkyls. PG,26
Claim 2
Dependent Claim
144 words
In an electrolytic cell of the type having an anode in an anode chamber; a cathode in a cathode chamber and an ion exchange membrane separating the anode chamber from the cathode chamber, wherein said membrane is a copolymer of CFXCF 2 , where X is F or Cl, and a fluorinated vinyl ether compound having sulfonyl ion exchange functionality, wherein said copolymer has a polymeric backbone with sulfonyl-containing pendant groups attached thereto; wherein the improvement comprises the copolymer having additional pendant groups attached to the backbone represented by the formula: ##STR11## where X' and X'" are independently selected from the group consisting of F, Cl and Br n', a' and b' are independently zero or an integer greater than zero, provided n'+a'+b'≠0 R f and R f ' are independently selected from the group consisting of fluorine, chlorine, fluoroalkyls and chlorofluoro alkyls. PG,26
Claim 3
Dependent Claim
68 words
The cell of claim 1 wherein the sulfonyl-containing pendant groups are represented by the general formula: ##STR12## where n=0 or an integer greater than zero; X=F, Cl or Br; M=hydrogen or an alkali metal; R f and R f ' are independently selected the group consisting of F, Cl, fluoroalkyl and chlorofluoroalkyl; a=zero or an integer greater than zero; b=zero or an integer greater than zero, provided a+b≠0.
Claim 4
Dependent Claim
21 words
The cell of claims 1 or 2 where a'=0-3; b'=0-3; R f =Cl or F; and R f '=Cl or F.
Claim 5
Dependent Claim
15 words
The cell of claims 1 or 2 where n=0-3 and X'=Cl or F when n≠0.
Claim 6
Dependent Claim
9 words
The cell of claims 1 or 2 where n'=0.
Claim 7
Dependent Claim
13 words
The cell of claims 1 or 2 where n=0 and X'"=F or Cl.
Claim 8
Dependent Claim
7 words
The cell of claims 2 where n=0-3.
Claim 9
Dependent Claim
19 words
The cell of claims 2 where a=0-3; b=0-3; R f =Cl or F and R f '=Cl or F.
Claim 10
Dependent Claim
12 words
The cell of claim 2 wherein n=0; n'=0; and X'"=F or Cl.
Claim 11
Dependent Claim
9 words
The cell of claim 2 where n'=1 and n=0.
Claim 12
Dependent Claim
9 words
The cell of claim 2 where n'=0 and n=1.
Claim 13
Dependent Claim
9 words
The cell of claim 2 where X=Cl and X'=Cl.
Claim 14
Dependent Claim
55 words
An electrolytic method using the cell of claims 1, 2, 9, 10, 11 or 12 comprising: (a) feeding an alkali metal halide solution into the anode chamber; (b) impressing an electrical current to the anode and the cathode at a level sufficient to cause electrolysis; and (c) removing the products of electrolysis from the cell.
Claim 15
Dependent Claim
49 words
An electrolytic method using the cell of claim 3 comprising: (a) feeding an alkali metal halide solution into the anode chamber; (b) impressing an electrical current to the anode and the cathode at a level sufficient to cause electrolysis; and (c) removing the products of electrolysis from the cell.
Claim 16
Dependent Claim
49 words
An electrolytic method using the cell of claim 4 comprising: (a) feeding an alkali metal halide solution into the anode chamber; (b) impressing an electrical current to the anode and the cathode at a level sufficient to cause electrolysis; and (c) removing the products of electrolysis from the cell.
Claim 17
Dependent Claim
49 words
An electrolytic method using the cell of claim 5 comprising: (a) feeding an alkali metal halide solution into the anode chamber; (b) impressing an electrical current to the anode and the cathode at a level sufficient to cause electrolysis; and (c) removing the products of electrolysis from the cell.
Claim 18
Dependent Claim
49 words
An electrolytic method using the cell of claim 6 comprising: (a) feeding an alkali metal halide solution into the anode chamber; (b) impressing an electrical current to the anode and the cathode at a level sufficient to cause electrolysis; and (c) removing the products of electrolysis from the cell.
Claim 19
Dependent Claim
49 words
An electrolytic method using the cell of claim 7 comprising: (a) feeding an alkali metal halide solution into the anode chamber; (b) impressing an electrical current to the anode and the cathode at a level sufficient to cause electrolysis; and (c) removing the products of electrolysis from the cell.
Claim 20
Dependent Claim
49 words
An electrolytic method using the cell of claim 8 comprising: (a) feeding an alkali metal halide solution into the anode chamber; (b) impressing an electrical current to the anode and the cathode at a level sufficient to cause electrolysis; and (c) removing the products of electrolysis from the cell.
Claim 21
Dependent Claim
122 words
An improved ion exchange membrane suitable for use in a chlor-alkali electrolytic cell; said membrane being a copolymer of CFXCF 2 , where X is F or Cl, and a fluorinated vinyl ether compound having sulfonyl ion exchange functionality; wherein said copolymer has a polymeric backbone with sulfonyl-containing pendant groups attached thereto; wherein the improvement comprises the copolymer having additional pendant groups attached to the backbone represented by the formula: ##STR13## where X' and X'" are independently selected from the group consisting of F, Cl and Br n', a' and b' are independently zero or an integer greater than zero, provided n'+a'+b'≠0 R f and R f ' are independently selected from the group consisting of fluorine, chlorine, fluoroalkyls and chlorofluoro alkyls.
Claim 22
Dependent Claim
122 words
An improved ion exchange membrane suitable for use in a chlor-alkali electrolytic cell; said membrane being a copolymer of CFXCF 2 , where X is F or Cl, and a fluorinated vinyl ether compound having sulfonyl ion exchange functionality; wherein said copolymer has a polymeric backbone with sulfonyl-containing pendant groups attached thereto; wherein the improvement comprises the copolymer having additional pendant groups attached to the backbone represented by the formula: ##STR13## where X' and X'" are independently selected from the group consisting of F, Cl and Br n', a' and b' are independently zero or an integer greater than zero, provided n'+a'+b'≠0 R f and R f ' are independently selected from the group consisting of fluorine, chlorine, fluoroalkyls and chlorofluoro alkyls.
Claim 23
Dependent Claim
70 words
The membrane of claim 20 wherein the sulfonyl-containing pendant groups are represented by the general formula: ##STR14## where n=0 or an integer greater than zero; X=F, Cl or Br; M=hydrogen or an alkali metal; R f and R f ' are independently selected from the the group consisting of F, Cl, fluoroalkyl and chlorofluoroalkyl; a=zero or an integer greater than zero; b=zero or an integer greater than zero, provided a+b≠0.
Claim 24
Dependent Claim
21 words
The membrane of claims 20 or 21 where a'=0-3; b'=0-3; R f =Cl or F; and R f '=Cl or F.
Claim 25
Dependent Claim
15 words
The membrane of claims 20 or 21 where n=0-3 and X'=Cl or F when n≠0.
Claim 26
Dependent Claim
9 words
The membrane of claims 20 or 21 where n'=0.
Claim 27
Dependent Claim
13 words
The membrane of claims 20 or 21 where n=0 and X'"=F or Cl.
Claim 28
Dependent Claim
7 words
The membrane of claims 21 where n=0-3.
Claim 29
Dependent Claim
19 words
The membrane of claims 21 where a=0-3; b=0-3; R f =Cl or F and R f '=Cl or F.
Claim 30
Dependent Claim
12 words
The membrane of claim 21 where n=0; n'=0; and X'"=F or Cl.
Claim 31
Dependent Claim
9 words
The membrane of claim 21 where n'=1 and n=0.
Claim 32
Dependent Claim
9 words
The membrane of claim 21 where n'=0 and n=1.
Claim 33
Dependent Claim
9 words
The membrane of claim 21 where X=Cl and X'=Cl.
Claim 34
Dependent Claim
20 words
The membrane of claims 20 or 21 wherein at least 60 mole percent of the membrane is CFXCF 2 .
Claim 35
Dependent Claim
18 words
The membrane of claims 20 or 21 wherein the membrane has an equivalent weight of at least 600.
Claim 36
Dependent Claim
18 words
The cell of claims 1 or 2 wherein the membrane has an equivalent weight of at least 600.
Claim 37
Dependent Claim
20 words
The cell of claims 1 or 2 wherein at least 60 mole percent of the membrane is CFXCF 2 .
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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) | 1987-09-11 | 1988-03-12 | 1988-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-11 | 1992-03-12 | 1992-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-11 | 1996-03-12 | 1996-09-11 | $7700.00 | Window Closed / Lapsed |