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US4012324A
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Crosslinked, interpolymer fixed-charge membranes
Assignee: Individual
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Filing: 1974-01-15
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Granted: 1977-03-15
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Expires: 1994-01-15
Abstract
Abstract Interpolymer fixed-charge membranes of macroscopic homogeneity are prepared by providing a solution containing a matrix polymer, a polyelectrolyte and a crosslinking agent, evaporating the solvent until substantially the desired pore size and other physical properties are obtained in a film cast from the solution, the thereafter chemically crosslinking the film to insolubilize the membrane.
Inventors
- 👤 Harry P. Gregor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:57
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; C08J5/2268; B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0011; B01D67/0013; B01D69/00; B01D69/02; B29; B29D; B29D7/00; B29D7/01; B01D2323/00; B01D2323/30
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
80 words
A chemically cross-linked non-fouling polymeric membrane including polyelectrolytes having fixed-charge groups and characterized by a hydraulic permeability of 10.sup. -3 to 10.sup. -7 cm/sec. atm. measured in water or dilute salt solution under a pressure of 60 to 100 psi, a water content of from about 15 to about 75%, and characterized by a uniform porosity which produces a salt rejection of from 1.0 to 85% measured using 0.01 M potassium chloride solution at 25°C and 60 to 100 psi.
Claim 2
Dependent Claim
80 words
A chemically cross-linked non-fouling polymeric membrane including polyelectrolytes having fixed-charge groups and characterized by a hydraulic permeability of 10.sup. -3 to 10.sup. -7 cm/sec. atm. measured in water or dilute salt solution under a pressure of 60 to 100 psi, a water content of from about 15 to about 75%, and characterized by a uniform porosity which produces a salt rejection of from 1.0 to 85% measured using 0.01 M potassium chloride solution at 25°C and 60 to 100 psi.
Claim 3
Dependent Claim
19 words
The polymeric membrane of claim 1, wherein the fixed-charge groups are supplied by a polyelectrolyte containing sulfonic acid radicals.
Claim 4
Dependent Claim
19 words
The polymeric membrane of claim 1, wherein the fixed-charge groups are supplied by a polyelectrolyte containing quaternary ammonium radicals.
References Cited (Backward Citations)
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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) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |