US3593855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High flow porous reverse osmosis membranes containing lipids
Assignee: Westinghouse Electric Corp
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Filing: 1969-05-13
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Granted: 1971-07-20
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Expires: 1989-05-13
Abstract
Abstract A semipermeable membrane containing a supportive layer and a lipid containing osmotic skin layer of polymeric film forming cellulosic material is made by (1) admixing film forming cellulosic material, solvent, swelling additive and lipid to provide a casting solution (2) casting a film from the solution (3) drying the film (4) leaching the film to form a semipermeable osmotic skin membrane containing a residue of lipid, and (5) optionally curing the membrane.
Inventors
- 👤 Regis R Stana
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:03
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/22; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0011; B01D71/14; B01D2323/00; B01D2323/15; B01D2323/16
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
32 words
The semipermeable membrane of claim 1 wherein the polymeric film forming cellulosic material is selected from the group consisting of cellulose esters and cellulose ethers and the lipds are glycerol ester lipids.
Claim 2
Dependent Claim
37 words
The semipermeable membrane of claim 2 wherein the polymeric film forming cellulosic material is selected from the group consisting of cellulose acetate, cellulose acetate-butyrate, cellulose propionate and ethyl cellulose and the glycerol ester lipid has the formula
Claim 3
Dependent Claim
13 words
The semipermeable membrane of claim 3 wherein the glycerol ester lipid is triacetin.
Claim 4
Dependent Claim
19 words
The semipermeable membrane of claim 3 wherein the membrane is cured to reduce the size of the foraminous passageways.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |