US4255523A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cation exchange membrane of fluorinated polymer for electrolysis and preparation thereof
Assignee: AGC Inc
•
Filing: 1978-05-03
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Granted: 1981-03-10
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Expires: 1998-05-03
Abstract
Abstract A cation exchange membrane of a fluorinated polymer is formed by incorporating fibrils of polytetrafluoroethylene into a cation exchange resin of a fluorinated polymer having carboxylic acid groups or functional groups which can be converted to carboxylic acid groups.
Inventors
- 👤 Hiroshi Ukihashi
- 👤 Tatsuro Asawa
- 👤 Tomoki Gunjima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:45
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/34; C25B1/46; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; C08J5/2231; C08J5/2237; C08L; C08L27/00; C08L27/02; C08L27/12; C08L27/18; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
59 words
A fluorinated polymer cation exchange membrane for electrolysis which comprises a cation exchange resin of a perfluorocarbon polymer having carboxylic acid groups or functional groups which can be converted to carboxylic acid groups said resin having 0.5 to 2.8 wt. % fibrils of polytetrafluoroethylene incorporated therein, wherein said fibrils are formed by applying shear stress to particles of polytetrafluoroethylene.
Claim 2
Dependent Claim
59 words
A fluorinated polymer cation exchange membrane for electrolysis which comprises a cation exchange resin of a perfluorocarbon polymer having carboxylic acid groups or functional groups which can be converted to carboxylic acid groups said resin having 0.5 to 2.8 wt. % fibrils of polytetrafluoroethylene incorporated therein, wherein said fibrils are formed by applying shear stress to particles of polytetrafluoroethylene.
Claim 3
Dependent Claim
38 words
A cation exchange membrane according to claim 1 wherein 1.0 to 2.8 wt. % of the fibrils of polytetrafluoroethylene are incorporated based on the total weight of the fibrils and the cation exchange resin of a fluorinated polymer.
Claim 4
Dependent Claim
27 words
A cation exchange membrane according to claim 1 or 2 wherein the cation exchange resin has an ion exchange capacity of 0.5 to 2.5 meq/g dry polymer.
Claim 5
Dependent Claim
103 words
A cation exchange membrane according to claim 1 wherein the fluorinated polymer is comprised of 60 to 95 mole % of units (a) --CF 2 --CXX'-- and 5 to 40 mole % of units ##STR4## wherein X represents fluorine, or --CF 3 ; X' represents X or CF 3 (CF 2 ) m ; m represents 1 to 5; and Y represents ##STR5## wherein x, y and z respectively represent 1 to 10; Z and R f respectively represent -F or a C 1 -C 10 perfluoroalkyl group; A represents --COOH or a functional group which can be converted to --COOH by hydrolysis.
Claim 6
Dependent Claim
35 words
A cation exchange membrane according to claim 1 or 2 wherein the fibrils of polytetrafluoroethylene are fibrils of polytetrafluoroethylene having a specific surface area of 3 to 30 cm 2 /g prepared by emulsion polymerization.
Claim 7
Dependent Claim
48 words
A cation exchange membrane according to claim 1 or 3 wherein the fibrils of polytetrafluoroethylene are fibrils of a copolymer of tetrafluoroethylene having less than 5 mole % of units of a comonomer having the formula ##STR6## wherein R f represents a C 1 -C 10 fluoroalkyl group.
Claim 8
Dependent Claim
84 words
A process for preparing a cation exchange membrane of a fluorinated polymer for eletrolysis which comprises mixing 0.5 to 2.8 wt. % polytetrafluoroethylene for forming fibrils with a cation exchange resin of the fluorinated polymer having carboxylic acid groups or functional groups which can be converted to carboxylic acid groups; and kneading the mixture in the condition of applying shear stress to form fibrils of polytetrafluoroethylene and fabricating it to a membrane, wherein said membrane comprises from 0.5 to 2.8 wt. % of fibrils.
Claim 9
Dependent Claim
84 words
A process for preparing a cation exchange membrane of a fluorinated polymer for eletrolysis which comprises mixing 0.5 to 2.8 wt. % polytetrafluoroethylene for forming fibrils with a cation exchange resin of the fluorinated polymer having carboxylic acid groups or functional groups which can be converted to carboxylic acid groups; and kneading the mixture in the condition of applying shear stress to form fibrils of polytetrafluoroethylene and fabricating it to a membrane, wherein said membrane comprises from 0.5 to 2.8 wt. % of fibrils.
Claim 10
Dependent Claim
29 words
A process according to claim 7 wherein the fibrils of polytetrafluoroethylene are formed at a temperature higher than 100° C. and lower than the melting point of the polytetrafluoroethylene.
Claim 11
Dependent Claim
19 words
A process according to claim 7 wherein the polytetrafluoroethylene has a secondary particle diameter of less than 5 mm.
Claim 12
Dependent Claim
18 words
A process according to claim 7, 8, or 9 wherein the polytetrafluoroethylene is produced by an emulsion polymerization.
Claim 13
Dependent Claim
31 words
A cation exchange membrane according to claim 4 wherein A is selected from the group consisting of --CN, --COF, and COOR, wherein R represents a C 1 -C 10 alkyl group.
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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) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |