US4039440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reverse osmosis membrane
Assignee: United States Department of the Interior
•
Filing: 1975-01-16
•
Granted: 1977-08-02
•
Expires: 1995-01-16
Abstract
Abstract A reverse osmosis membrane is prepared by reaction of a film or layer of polyethylenimine with a polyfunctional reagent whose functional groups are capable of reacting with amine groups. The polyfunctional reagent is preferably a water-soluble, aromatic or heterocyclic compound having acid chloride or isocyanate functional groups.
Inventors
- 👤 John E. Cadotte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:42
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D69/125; B01D71/00; B01D71/06; B01D71/58; B01D71/60; B01D71/601
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
79 words
A process for the preparation of a reverse osmosis membrane consisting of the steps of (1) coating a porous support with a film of polyethyleneimine; (2) contacting the product of step (1) with a solution of a polyfunctional cross-linking reagent in a non-polar organic solvent, said cross-linking reagent consisting of isophthaloyl chloride; and () heat curing the product of step (2) at a temperature of about 90° to 130° C. for a period of about 5 to 30 minutes.
Claim 2
Dependent Claim
79 words
A process for the preparation of a reverse osmosis membrane consisting of the steps of (1) coating a porous support with a film of polyethyleneimine; (2) contacting the product of step (1) with a solution of a polyfunctional cross-linking reagent in a non-polar organic solvent, said cross-linking reagent consisting of isophthaloyl chloride; and () heat curing the product of step (2) at a temperature of about 90° to 130° C. for a period of about 5 to 30 minutes.
Claim 3
Dependent Claim
12 words
The process of claim 1 in which said porous support comprises polysulfone.
Claim 4
Dependent Claim
14 words
The process of claim 1 in which said porous support comprises chlorinated polyvinyl chloride.
Claim 5
Dependent Claim
11 words
A reverse osmosis membrane prepared by the process of claim 1.
Claim 6
Dependent Claim
37 words
In a process for desalination of saline water by reverse osmosis comprising contacting the saline water under pressure with a reverse osmosis membrane, the improvement comprising using the membrane of claim 4 as the reverse osmosis membrane.
References Cited (Backward Citations)
US3723306A
Cited
US3276996A
Cited
US3647086A
Cited
US3744642A
Cited
US3714010A
Cited
US3951815A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |