US4132682A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing cation-exchange membrane
Assignee: Tosoh Corp
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Filing: 1977-06-27
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Granted: 1979-01-02
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Expires: 1997-06-27
Abstract
Abstract A cation-exchange membrane is prepared by impregnating a diene monomer having carboxylic acid group or a functional group which can be converted to a carboxylic acid group, into a fluorinated polymer membrane having cation-exchangeable groups; partially polymerizing said diene monomer; swelling the membrane with a water miscible organic solvent and heat-treating the swollen membrane and if necessary, converting the functional groups to carboxylic acid groups.
Inventors
- 👤 Toru Seita
- 👤 Kenji Takahashi
- 👤 Shunichi Asami
- 👤 Akihiko Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:42
CPC Classifications
C; C08; C08F; C08F259/00; C08F259/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
76 words
A process for preparing a cation-exchange membrane which comprises impregnating a diene monomer having at least one carboxylic acid group or functional group which can be converted to a carboxylic acid group into a fluorinated polymer membrane having cation-exchangeable groups; partially polymerizing said diene monomer; swelling said membrane with a water miscible organic solvent and heat-treating the swollen membrane and converting to carboxylic acid groups said functional groups which can be converted to carboxylic acid groups.
Claim 2
Dependent Claim
76 words
A process for preparing a cation-exchange membrane which comprises impregnating a diene monomer having at least one carboxylic acid group or functional group which can be converted to a carboxylic acid group into a fluorinated polymer membrane having cation-exchangeable groups; partially polymerizing said diene monomer; swelling said membrane with a water miscible organic solvent and heat-treating the swollen membrane and converting to carboxylic acid groups said functional groups which can be converted to carboxylic acid groups.
Claim 3
Dependent Claim
40 words
A process according to claim 1, wherein said fluorinated polymer membrane having cation-exchangeable groups is treated by swelling it with a water miscible organic solvent and removing said solvent under reduced pressure or atmospheric pressure before impregnating said diene monomer.
Claim 4
Dependent Claim
33 words
A process according to claim 1, wherein said fluorinated polymer membrane having cation-exchangeable groups is treated by swelling it with a water miscible organic solvent and heat-treating it before impregnating said diene monomer.
Claim 5
Dependent Claim
27 words
A process according to claim 1, wherein said water miscible solvent is miscible with water at least to the extent of 0.1 g/100 g H 2 O.
Claim 6
Dependent Claim
25 words
A process according to claim 1, wherein said water miscible solvent is selected from the group consisting of aliphatic alcohols, esters, ketones, ethers and chloroform.
Claim 7
Dependent Claim
16 words
A process according to claim 1, wherein said water miscible solvent is methanol, ethanol,propanol or butanol.
Claim 8
Dependent Claim
19 words
A process according to claim 1, wherein said water miscible solvent is a lower alkyl ester, tetrahydrofuran or chloroform.
Claim 9
Dependent Claim
33 words
A process according to claim 1, wherein said fluorinated polymer membrane contains, after hydrolysis, acidic groups selected from the group consisting of sulfonic acid groups and carboxylic acid groups as cation exchangeable groups.
Claim 10
Dependent Claim
33 words
A process according to claim 1, wherein said diene monomer having a carboxylic acid group or a functional group which can be converted to a carboxylic acid group is a conjugated diene monomer.
Claim 11
Dependent Claim
38 words
A process according to claim 1, wherein said partial polymerization is carried out by thermal polymerization, radical polymerization, photopolymerization or radiation-induced polymerization, to such an extent that said cation-exchange membrane is swellable by said water miscible organic solvent.
Claim 12
Dependent Claim
33 words
A process according to claim 1, wherein said diene monomer having a carboxylic acid group or a functional group which can be converted to a carboxylic acid group is a non-conjugated diene monomer.
References Cited (Backward Citations)
US3839172A
Cited
US4012303A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-01 | 1982-07-03 | 1983-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-01 | 1986-07-03 | 1987-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-01 | 1990-07-03 | 1991-01-02 | $7700.00 | Window Closed / Lapsed |