US4262041A
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US
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Process for preparing a composite amphoteric ion exchange membrane
Assignee: Kanegafuchi Chemical Industry Co Ltd
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Filing: 1978-02-02
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Granted: 1981-04-14
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Expires: 1998-02-02
Abstract
Abstract A process for preparing a composite amphoteric ion exchange membrane, which comprises forming a thin membrane not exceeding 5 microns thick by applying to a surface of a microporous polymer substrate having a physical, selective permeability of its own, a coating consisting of a polymer having either a cation or anion exchange group and a functional group capable of receiving another ion exchange group having an opposite sign from the cation or anion exchange group or a mixture of two polymers one of which has either a cation or an anion exchange group and the other of which has a functional group capable of receiving an ion exchange group having an opposite sign from the cation or anion exchange group, and introducing the ion exchange group having an opposite sign to said functional group to provide a ratio of anion to cation exchange capacity in the range of from 0.5 to 2.0.
Inventors
- 👤 Tamiyuki Eguchi
- 👤 Seiichi Mori
- 👤 Masaaki Shimokawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:52
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2275; C08J2327/00; C08J2327/02; C08J2327/04; C08J2327/06
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
149 words
A process for preparing a composite amphoteric ion exchange membrane, which comprises forming a thin membrane not exceeding 5 microns thick by applying to a microporous polymer substrate having a physical, selective permeability of its own, a coating consisting of a polymer having either a cation or anion exchange group and a functional group capable of receiving another ion exchange group having an opposite sign from the cation or anion exchange group or a mixture of two polymers one of which was either a cation or an anion exchange group and the other of which has a functional group capable of receiving an ion exchange group having an opposite sign from the cation or anion exchange group, and introducing the ion exchange group having an opposite sign to said functional group to provide a ratio of anion to cation exchange capacity in the range of from 0.5 to 2.0.
Claim 2
Dependent Claim
149 words
A process for preparing a composite amphoteric ion exchange membrane, which comprises forming a thin membrane not exceeding 5 microns thick by applying to a microporous polymer substrate having a physical, selective permeability of its own, a coating consisting of a polymer having either a cation or anion exchange group and a functional group capable of receiving another ion exchange group having an opposite sign from the cation or anion exchange group or a mixture of two polymers one of which was either a cation or an anion exchange group and the other of which has a functional group capable of receiving an ion exchange group having an opposite sign from the cation or anion exchange group, and introducing the ion exchange group having an opposite sign to said functional group to provide a ratio of anion to cation exchange capacity in the range of from 0.5 to 2.0.
Claim 3
Dependent Claim
24 words
The process according to claim 1, wherein the ratio of anion to cation exchange capacity is in the range of from 0.67 to 1.5.
Claim 4
Dependent Claim
24 words
The process according to claim 2, wherein the ratio of anion to cation exchange capacity is in the range of from 0.8 to 1.25.
Claim 5
Dependent Claim
67 words
The process according to claim 1, wherein the microporous polymer substrate is coated with a composition containing a polymer having a quaternary ammonium group and a functional group capable of receiving a sulfonic acid group, the composition is cross-linked in the presence of concentrated sulfuric acid, and the introduction of the sulfonic acid group and cross-linking are simultaneously carried out in the presence of concentrates sulfuric acid.
Claim 6
Dependent Claim
92 words
The process according to claim 1, wherein the microporous polymer substrate is coated with a composition containing two polymers, one of which has a quaternary ammonium group and a functional group capable of being cross-linked in the presence of sulfuric acid and the other of which has a functional group capable of receiving a sulfonic acid group and a functional group capable of being cross-linked in the presence of sulfuric acid, the introduction of the sulfonic acid group and the cross-linking being simultaneously carried out in the presence of concentrated sulfuric acid.
Claim 7
Dependent Claim
40 words
The process according to claim 4, wherein the functional group capable of receiving a sulfonic acid group is a phenyl group and the functional group capable of being cross-linked is a phenyl group having attached thereto an alkyl halide group.
Claim 8
Dependent Claim
40 words
The process according to claim 5, wherein the functional group capable of receiving a sulfonic acid group is a phenyl group and the functional group capable of being cross-linked is a phenyl group having attached thereto an alkyl halide group.
Claim 9
Dependent Claim
55 words
The process according to claim 4, wherein a polystyrene in which some benzene rings have an alkyl halide group is modified to possess a quaternary ammonium group by the use of tertiary amine which reacts with a part of said alkyl halide group and the microporous polymer substrate is coated with the polymer thus modified.
Claim 10
Dependent Claim
19 words
The process according to claim 4, wherein the concentration of sulfuric acid is 90 percent by weight or more.
Claim 11
Dependent Claim
19 words
The process according to claim 5, wherein the concentration of sulfuric acid is 90 percent by weight or more.
Claim 12
Dependent Claim
19 words
The process according to claim 8, wherein the concentration of sulfuric acid is 94 to 97 percent by weight.
Claim 13
Dependent Claim
41 words
The process according to claim 1, wherein the anion is one member or a mixture of at least two members selected from the group consisting of a primary, a secondary and a tertiary ammonium group and the cation is carboxylic acid.
Claim 14
Dependent Claim
14 words
The process according to claim 1, wherein the microporous polymer substrate is polyvinyl chloride.
Claim 15
Dependent Claim
141 words
A process for preparing a composite amphoteric ion exchange membrane, which comprises forming a thin membrane not exceeding 5 microns thick by applying to a microporous polymer substrate having a physical, selective permeability of its own, a coating consisting of a polymer having an ion exchange group which is either a quaternary ammonium group or a sulfonic acid group and a functional group capable of receiving the other exchange group or of a mixture of two polymers one of which has an ion exchange group which is either a quaternary ammonium group or a sulfonic acid group and the other of which has a functional group capable of receiving the other exchange group; and introducing said other ion exchange group to said functional group to provide a ratio of anion to cation exchange capacity in the range of 0.5 to 2.0.
Claim 16
Dependent Claim
141 words
A process for preparing a composite amphoteric ion exchange membrane, which comprises forming a thin membrane not exceeding 5 microns thick by applying to a microporous polymer substrate having a physical, selective permeability of its own, a coating consisting of a polymer having an ion exchange group which is either a quaternary ammonium group or a sulfonic acid group and a functional group capable of receiving the other exchange group or of a mixture of two polymers one of which has an ion exchange group which is either a quaternary ammonium group or a sulfonic acid group and the other of which has a functional group capable of receiving the other exchange group; and introducing said other ion exchange group to said functional group to provide a ratio of anion to cation exchange capacity in the range of 0.5 to 2.0.
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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) | 1984-04-13 | 1984-10-13 | 1985-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-13 | 1988-10-13 | 1989-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-13 | 1992-10-13 | 1993-04-14 | $7700.00 | Window Closed / Lapsed |