US4663050A
Expired / Lapsed
US
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Semipermeable membranes prepared from polymers containing adjacent, pendent carboxy groups
Assignee: Standard Oil Co
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Filing: 1983-06-01
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Granted: 1987-05-05
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Expires: 2003-06-01
Abstract
Abstract Semipermeable membranes useful for separating mixtures of ethanol and water into enriched fractions of each are prepared by cross-linking 50-90 weight percent of at least one polymer containing pendent, adjacent carboxy groups with 10-50 weight percent of at least one diamine. Membranes prepared from copolymers of maleic anhydride and styrene cross-linked with a polyoxyalkylene diamine are exemplary. These membranes are also useful in gas separation processes, such as separating oxygen from nitrogen.
Inventors
- 👤 George S. Li
- 👤 William M. Giffen, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:10
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/40
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
41 words
A semipermeable membrane comprising about: (a) 50-90 weight percent of at least one polymer containing pendent, adjacent carboxy groups, and (b) 10-50 weight percent of at least one long-chain diamine having a weight average molecular weight of at least about 2,000.
Claim 2
Dependent Claim
41 words
A semipermeable membrane comprising about: (a) 50-90 weight percent of at least one polymer containing pendent, adjacent carboxy groups, and (b) 10-50 weight percent of at least one long-chain diamine having a weight average molecular weight of at least about 2,000.
Claim 3
Dependent Claim
69 words
The membrane of claim 1 where the polymer is a copolymer prepared from about (a) 3-50 molar parts of a monomer selected from maleic anhydride, maleic acid, an ester of maleic acid, and α,β-unsaturated dicarboxylic acids, anhydrides and their lower alkyl esters where a carbon to carbon double bond is an α,β-position to both of the carboxy functions, and (b) 97-50 molar parts of at least one vinyl monomer.
Claim 4
Dependent Claim
28 words
The membrane of claim 2 where the monomer of (a) is selected from maleic anhydride, maleic acid and a C 1 -C 4 alkyl ester of maleic acid.
Claim 5
Dependent Claim
25 words
The membrane of claim 3 where the vinyl monomer of (b) is selected from aliphatic and aromatic compounds having up to about 18 carbon atoms.
Claim 6
Dependent Claim
11 words
The membrane of claim 4 where the vinyl monomer is styrene.
Claim 7
Dependent Claim
13 words
The membrane of claim 5 where the monomer of (a) is maleic anhydride.
Claim 8
Dependent Claim
24 words
The membrane of claim 6 where the copolymer is prepared from about 6-50 molar parts of maleic anhydride and about 94-50 molar parts styrene.
Claim 9
Dependent Claim
20 words
The membrane of claim 7 where the weight average molecular weight of the polymer is between about 10,000 and 200,000.
Claim 10
Dependent Claim
20 words
The membrane of claim 8 where the weight average molecular weight of the polymer is between about 50,000 and 100,000.
Claim 11
Dependent Claim
21 words
The membrane of claim 9 where the diamine is a substantially linear polyoxyalkylene terminated at each end with an amine group.
Claim 12
Dependent Claim
21 words
The membrane of claim 10 where the diamine is a substantially linear polyoxypropylene terminated at each end with an amine group.
Claim 13
Dependent Claim
20 words
The membrane of claim 11 where the diamine has a weight average molecular weight of between about 2,000 and 10,000.
Claim 14
Dependent Claim
16 words
The membrane of claim 12 where at least part of the carboxy groups are acid groups.
Claim 15
Dependent Claim
18 words
The membrane of claim 12 where at least part of the carboxy groups are NH 4 + salts.
Claim 16
Dependent Claim
14 words
The membrane of claim 12 having a thickness between 25 mils and 1,000 angstroms.
Claim 17
Dependent Claim
58 words
A process of separating a liquid mixture of ethanol and water into enriched fractions of each, the process comprising contacting the mixture with the membrane of claim 1 in such a manner that the water portion of the mixture is selectively passed through the membrane while the ethanol portion of the mixture is selectively rejected by the membrane.
Claim 18
Dependent Claim
58 words
A process of separating a gaseous mixture containing oxygen and nitrogen into enriched fractions of each, the process comprising contacting the mixture with the membrane of claim 1 in such a manner that the oxygen portion of the mixture is selectively passed through the membrane while the nitrogen portion of the mixture is selectively rejected by the membrane.
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) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |