US3945927A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ion-exchange group bearing composite membranes
Assignee: Kanegafuchi Chemical Industry Co Ltd
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Filing: 1974-09-10
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Granted: 1976-03-23
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Expires: 1994-09-10
Abstract
Abstract Composite membranes bearing ion-exchange groups suitable for use in membrane separation processes are produced by providing a porous substrate which is physically semipermeable by itself, applying a coating composition consisting essentially of a filmforming polymeric material to which ion-exchange groups are introduceable and a liquid medium onto the surface of said substrate, removing said liquid medium to provide an ultrathin membrane of said material having a thickness less than 10 microns, and treating said ultrathin membrane to provide said ion-exchange groups throughout said ultrathin membrane.
Inventors
- 👤 Satoshi Imai
- 👤 Tamiyuki Eguchi
- 👤 Masaaki Shimokawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:34
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0093; B01D67/00931; B01D69/00; B01D69/12; C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2275; B01D2323/00; B01D2323/30; C08J2327/00; C08J2327/02; C08J2327/04; C08J2327/06; C08J2409/00; C08J2409/06; C08J2427/00; C08J2427/02; C08J2427/04; C08J2427/06
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
137 words
A method for preparing a selectively permeable composite membrane having an ultrathin layer of ion exchange polymer film adhered to a polymeric microporous supporting substrate which is permeable to ions and molecules which pass through said ultrathin layer, which comprises: a. coating said substrate with a composition consisting essentially of an inert diluent and a film-forming polymer which is substantially impermeable to said substrate and which contains at least on reactive site selected from the group consisting of benzene rings, double bonds, halogen atoms, hydroxyl groups or nitrile groups; b. removing said inert diluent to form an ultrathin layer of said film-forming polymer having a dry thickness of less than 10 microns adhered to said substrate; and c. converting said ultrathin layer into an ion exchange layer by chemically introducing ion exchange groups into said reactive sites.
Claim 2
Independent Claim
137 words
A method for preparing a selectively permeable composite membrane having an ultrathin layer of ion exchange polymer film adhered to a polymeric microporous supporting substrate which is permeable to ions and molecules which pass through said ultrathin layer, which comprises: a. coating said substrate with a composition consisting essentially of an inert diluent and a film-forming polymer which is substantially impermeable to said substrate and which contains at least on reactive site selected from the group consisting of benzene rings, double bonds, halogen atoms, hydroxyl groups or nitrile groups; b. removing said inert diluent to form an ultrathin layer of said film-forming polymer having a dry thickness of less than 10 microns adhered to said substrate; and c. converting said ultrathin layer into an ion exchange layer by chemically introducing ion exchange groups into said reactive sites.
Claim 3
Dependent Claim
30 words
A method according to claim 1, wherein said ion exchange groups are at least one member selected from the group consisting of sulfonyl, carboxyl, quaternary ammonium and tertiary amino groups.
Claim 4
Dependent Claim
28 words
A method according to claim 1, wherein said film-forming polymer is selected from the group consisting of a butadiene-styrene copolymer, a vinyl chloride-acrylonitrile copolymer and a polyvinyl alcohol.
Claim 5
Dependent Claim
11 words
A method according to claim 1, wherein said substrate comprises polyvinylchloride.
Claim 6
Dependent Claim
17 words
A method according to claim 4, wherein the film-forming polymer is a copolymer of butadiene and styrene.
Claim 7
Dependent Claim
23 words
A method according to claim 5, wherein said ion exchange groups are introduced by sulfonating benzene ring reactive sites in said ultrathin layer.
Claim 8
Dependent Claim
27 words
A method according to claim 6, further comprising reacting the resultant ion exchange layer with a mixture of epichlorohydrin and pyridine to introduce quaternary ammonium groups therein.
Claim 9
Dependent Claim
18 words
A method according to claim 4, wherein said film-forming polymer is a copolymer of vinyl chloride and acrylonitrile.
Claim 10
Dependent Claim
28 words
A method according to claim 8, wherein said ion exchange groups are introduced by substituting halogen atom reactive sites in said ultrathin layer with a tertiary amino group.
Claim 11
Dependent Claim
23 words
A method according to claim 8, wherein said ion exchange groups are introduced by hydrolyzing nitrile group reactive sites in said ultrathin layer.
Claim 12
Dependent Claim
22 words
A method according to claim 10, further comprising reacting the resultant ion exchange layer with ethylenediamine to introduce tertiary amino groups therein.
Claim 13
Dependent Claim
13 words
A selectively permeable composite membrane prepared according to the process of claim 1.
Claim 14
Dependent Claim
13 words
A selectively permeable composite membrane prepared according to the process of claim 2.
Claim 15
Dependent Claim
13 words
A selectively permeable composite membrane prepared according to the process of claim 3.
Claim 16
Dependent Claim
13 words
A selectively permeable composite membrane prepared according to the process of claim 4.
Claim 17
Dependent Claim
13 words
A selectively permeable composite membrane prepared according to the process of claim 6.
Claim 18
Dependent Claim
13 words
A selectively permeable composite membrane prepared according to the process of claim 7.
Claim 19
Dependent Claim
13 words
A selectively permeable composite membrane prepared according to the process of claim 10.
Claim 20
Dependent Claim
13 words
A selectively permeable composite membrane prepared according to the process of claim 11.
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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) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |