US3673084A
Expired / Lapsed
US
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Reverse osmosis and process and composition for manufacturing cellulose acetate membranes wherein the swelling agent is a di-or tri-basic aliphatic acid
Assignee: Aerojet Rocketdyne Inc
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Filing: 1969-07-14
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Granted: 1972-06-27
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Expires: 1989-07-14
Abstract
Abstract A casting solution for the preparation of a cellulose membrance containing cellulose acetate, an organic solvent and a watersoluble organic swelling agent, which is capable of hydrogen bonding with ketone and hydroxyl groups of the cellulose acetate, said organic swelling agent being present in an amount between about 1.0 to about 10 parts by weight of each 10 parts of the cellulose acetate, said organic swelling agent being of a different composition than the organic solvent and being, for example, a di- or a tri-basic aliphatic acid having from two to 13 carbon atoms.
Inventors
- 👤 William M King
- 👤 Paul A Cantor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:59
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/14; B01D71/16; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0011; B01D67/0081; B01D67/0083; B01D2323/00; B01D2323/15; B01D2323/16
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
110 words
In a process of forming a cellulose acetate membrane as for reverse osmosis, the improvement comprising forming a casting solution containing cellulose acetate, an organic solvent and a water-soluble organic swelling agent, which is capable of hydrogen bonding with ketone and hydroxyl groups of the cellulose acetate, said organic swelling agent being present in an amount ranging between about 1.0 to about 10 parts by weight for each 10 parts of the cellulose acetate, and casting said solution to form a membrane, said organic swelling agent being of a different composition than the organic solvent and being a di- or tri-basic aliphatic acid having from two to 13 carbon atoms.
Claim 2
Dependent Claim
11 words
A process of claim 2 wherein said acid is malonic acid.
Claim 3
Dependent Claim
11 words
A process of claim 2 wherein said acid is oxalic acid.
Claim 4
Dependent Claim
11 words
A process of claim 2 wherein said acid is succinic acid.
Claim 5
Dependent Claim
11 words
A process of claim 2 wherein said acid is glutaric acid.
Claim 6
Dependent Claim
11 words
A process of claim 2 wherein said acid is maleic acid.
Claim 7
Dependent Claim
11 words
A process of claim 2 wherein said acid is tartaric acid.
Claim 8
Dependent Claim
11 words
A process of claim 2 wherein said acid is glycolic acid.
Claim 9
Dependent Claim
11 words
A process of claim 2 wherein said acid is lactic acid.
Claim 10
Dependent Claim
11 words
A process of claim 2 wherein said acid is citric acid.
Claim 11
Dependent Claim
92 words
A casting solution for the preparation of a cellulose acetate membrane, containing cellulose acetate, an organic solvent and a water-soluble organic swelling agent, which is capable of hydrogen bonding with ketone and hydroxyl groups of the cellulose acetate, said organic swelling agent being present in an amount between about 1 to about 10 parts by weight for each 10 parts of the cellulose acetate, said organic swelling agent being of a different composition than the organic solvent and being a di- or tri-basic aliphatic acid having from two to 13 carbon atoms.
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |