Patent US4036728A successfully refreshed from Google Patents.
US4036728A
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Converting a diaphragm electrolytic cell to a membrane electrolytic cell
Assignee: Diamond Shamrock Corp
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Filing: 1976-05-21
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Granted: 1977-07-19
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Expires: 1996-05-21
Abstract
Abstract Disclosed is a method for converting a diaphragm electrolytic cell to a membrane electrolytic cell by using the standard diaphragm cell equipment and applying a membrane over top of a matting material upon the cathode surface. This method permits a manufacturer having a diaphragm electrolytic cells to convert those cells to membrane electrolytic cells without significant capital expenditure to achieve the desirable characteristics of a membrane electrolytic cell.
Inventors
- 👤 Andrew D. Babinsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:04
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; C08J5/2231; C08J5/2237; C25; C25B; C25B13/00; C25B13/04; C25B13/05; C25B13/06; C25B13/08; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
138 words
A method for forming a membrane over a standard diaphragm cell foraminous electrode comprising the steps of: suspending a matting material in a fluid medium; inserting a foraminous electrode into the suspension; vacuum forming a layer of the suspended matting material over the surface of the foraminous electrode so as to substantially reduce the porosity of the foraminous electrode material; applying to the surface of the foraminous electrode with the matting material thereon, a layer of thermoplastic material including NAFION particles in the sulfonyl fluoride form; baking the foraminous electrode with the layers in place until the thermoplastic material is fused into a thin and uniform film on the surface of the matting material which is substantially impermeable to hydraulic flow; and hydrolyzing the NAFION to change the sulfonyl fluoride form to the cation exchange sulfonic acid form.
Claim 2
Independent Claim
138 words
A method for forming a membrane over a standard diaphragm cell foraminous electrode comprising the steps of: suspending a matting material in a fluid medium; inserting a foraminous electrode into the suspension; vacuum forming a layer of the suspended matting material over the surface of the foraminous electrode so as to substantially reduce the porosity of the foraminous electrode material; applying to the surface of the foraminous electrode with the matting material thereon, a layer of thermoplastic material including NAFION particles in the sulfonyl fluoride form; baking the foraminous electrode with the layers in place until the thermoplastic material is fused into a thin and uniform film on the surface of the matting material which is substantially impermeable to hydraulic flow; and hydrolyzing the NAFION to change the sulfonyl fluoride form to the cation exchange sulfonic acid form.
Claim 3
Dependent Claim
24 words
A method according to claim 1 wherein the thermoplastic material is applied by vacuum forming a slurry of thermoplastic material in FREON 113 solvent.
Claim 4
Dependent Claim
15 words
A method according to claim 1 wherein the thermoplastic material is applied by plasma spray.
Claim 5
Dependent Claim
23 words
A method according to claim 1 wherein said baking step is done at a temperature within the range of 240° to 300° C.
Claim 6
Dependent Claim
38 words
A method according to claim 1 wherein said hydrolyzing step is done in a solution having active ingredients selected from the group of: sodium hydroxide, potassium hydroxide, sodium hydroxide in dimethyl sulfoxide, or potassium hydroxide in dimethyl sulfoxide.
Claim 7
Dependent Claim
19 words
A method according to claim 1 wherein the matting material is selected from the group of: asbestos or cellulose.
Claim 8
Dependent Claim
173 words
A membrane separator for a standard diaphragm electrolytic cell comprising: a standard diaphragm cell foraminous electrode; on the surface of said standard diaphragm cell foraminous electrode, a layer of a matting material of such thickness as to substantially reduce the porosity of said standard diaphragm cell foraminous electrode; and on the surface of said matting material, a thin and uniform hydraulically impermeable cation exchange membrane consisting essentially of a film of copolymer having the repeating structural units of the formula: ##STR5## wherein R represents the group ##STR6## in which R 1 is fluorine or perfluoroalkyl of 1 to 10 carbon atoms; Y is fluorine or trifluoromethyl; m is 1, 2 or 3; n is 0 or 1; x is fluorine, chlorine, or trifluoromethyl; x 1 is x or CF 3 (CF 2 ) a O-; a is 0 or integer from 1 to 5; and the units of formula (1) being present in an amount to provide a copolymer having a --SO 3 H equivalent weight in the range of 800 to 1600.
Claim 9
Dependent Claim
173 words
A membrane separator for a standard diaphragm electrolytic cell comprising: a standard diaphragm cell foraminous electrode; on the surface of said standard diaphragm cell foraminous electrode, a layer of a matting material of such thickness as to substantially reduce the porosity of said standard diaphragm cell foraminous electrode; and on the surface of said matting material, a thin and uniform hydraulically impermeable cation exchange membrane consisting essentially of a film of copolymer having the repeating structural units of the formula: ##STR5## wherein R represents the group ##STR6## in which R 1 is fluorine or perfluoroalkyl of 1 to 10 carbon atoms; Y is fluorine or trifluoromethyl; m is 1, 2 or 3; n is 0 or 1; x is fluorine, chlorine, or trifluoromethyl; x 1 is x or CF 3 (CF 2 ) a O-; a is 0 or integer from 1 to 5; and the units of formula (1) being present in an amount to provide a copolymer having a --SO 3 H equivalent weight in the range of 800 to 1600.
Claim 10
Dependent Claim
22 words
A membrane separator according to claim 7 wherein said membrane material is surface treated to improve the selectivity of said membrane material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |