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US4717394A
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Polyimide gas separation membranes
Assignee: LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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Filing: 1986-10-27
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Granted: 1988-01-05
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Expires: 2006-10-27
Abstract
Abstract Semi-flexible aromatic polyimides, prepared by polycondensation of dianhydrides with diamines having alkyl substituents on all ortho positions to the amine functions, or with mixtures of diamines, some components having substituents on all positions ortho to the amine functions, are disclosed. Membranes formed from this class of polyimides have improved environmental stability and superior gas permeability. The range of gas permeation properties observed allows for the tailoring of membrane material for widely diverse gas separations. The high permeabilities of some gases from multicomponent mixtures is due to the optimization of the molecular free volume in the polymer.
Inventors
- 👤 Richard A. Hayes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:02
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1039; B; B01; B01D; B01D71/00; B01D71/06; B01D71/58; B01D71/62; B01D71/64; C08G73/1057; C08G73/1064; C08G73/1067; C08G73/1071; C08G73/1075
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
159 words
A process for separating gases comprising bringing two or more gases under pressuer into contact with a membrane formed of an aromatic polyimide comprising units of the formula ##STR11## where --Ar-- is ##STR12## or mixtures thereof, R is ##STR13## or mixtures thereof, --Ar'-- is ##STR14## or mixtures thereof, ##STR15## is ##STR16## or mixtures thereof, and --R"-- is ##STR17## where n=0 to 4, alkylene radicals of 1 to 3 carbon atoms or mixtures thereof, --X, --X 1 , --X 2 , and --X 3 are independently alkyl groups having 1 to 6 carbon atoms preferably methyl or ethyl, or aromatic groups of 6 to 13 carbon atoms, Z is --H, --X, --X 1 , --X 2 , or --X 3 W is 5% to 100% Q is 5% to 100% Y is 100% minus W V is 100% minus V Y plus V is at least 5%, whereby at least one of said gases is enriched upon permeating the membrane.
Claim 2
Dependent Claim
159 words
A process for separating gases comprising bringing two or more gases under pressuer into contact with a membrane formed of an aromatic polyimide comprising units of the formula ##STR11## where --Ar-- is ##STR12## or mixtures thereof, R is ##STR13## or mixtures thereof, --Ar'-- is ##STR14## or mixtures thereof, ##STR15## is ##STR16## or mixtures thereof, and --R"-- is ##STR17## where n=0 to 4, alkylene radicals of 1 to 3 carbon atoms or mixtures thereof, --X, --X 1 , --X 2 , and --X 3 are independently alkyl groups having 1 to 6 carbon atoms preferably methyl or ethyl, or aromatic groups of 6 to 13 carbon atoms, Z is --H, --X, --X 1 , --X 2 , or --X 3 W is 5% to 100% Q is 5% to 100% Y is 100% minus W V is 100% minus V Y plus V is at least 5%, whereby at least one of said gases is enriched upon permeating the membrane.
Claim 3
Dependent Claim
26 words
The The process of claim 1 wherein --X, --X 1 , --X 2 , or --X 3 are --CH 3 or --C 2 H 5 .
Claim 4
Dependent Claim
12 words
The process of claim 2 wherein R is ##STR18## or mixtures thereof.
Claim 5
Dependent Claim
132 words
A gas separation membrane formed of an aromatic polyimide comprising units of the formula ##STR19## where --Ar-- is ##STR20## or mixtures thereof, --R-- is ##STR21## or mixtures thereof, --Ar'-- is ##STR22## or mixtures thereof, ##STR23## is ##STR24## or mixtures thereof, and --R"-- is ##STR25## where n=0 to 4, alkylene radicals of 1 to 3 carbon atoms or mixtures thereof, --X, --X 1 , --X 2 , and --X 3 are independently alkyl groups having 1 to 6 carbon atoms preferably methyl or ethyl, or aromatic groups of 6 to 13 carbon atoms, Z is --H, --X, --X 1 , --X 2 , or X 3 W is 5% to 100% Q is 5% to 100% Y is 100% minus W V is 100% minus V Y plus V is at least 5%.
Claim 6
Dependent Claim
132 words
A gas separation membrane formed of an aromatic polyimide comprising units of the formula ##STR19## where --Ar-- is ##STR20## or mixtures thereof, --R-- is ##STR21## or mixtures thereof, --Ar'-- is ##STR22## or mixtures thereof, ##STR23## is ##STR24## or mixtures thereof, and --R"-- is ##STR25## where n=0 to 4, alkylene radicals of 1 to 3 carbon atoms or mixtures thereof, --X, --X 1 , --X 2 , and --X 3 are independently alkyl groups having 1 to 6 carbon atoms preferably methyl or ethyl, or aromatic groups of 6 to 13 carbon atoms, Z is --H, --X, --X 1 , --X 2 , or X 3 W is 5% to 100% Q is 5% to 100% Y is 100% minus W V is 100% minus V Y plus V is at least 5%.
Claim 7
Dependent Claim
13 words
The membrane of claim 4 wherein Y plus V is 10 to 50%.
Claim 8
Dependent Claim
25 words
The membrane of claim 5 wherein --X, --X 1 , --X 2 , or --X 3 are --CH 3 or --C 2 H 5 .
Claim 9
Dependent Claim
9 words
The membrane of claim 6 wherein Y is --0.
References Cited (Backward Citations)
US30351A
Cited
US3822202A
Cited
GB1435151A
Cited
USRE30351E
Cited
US3816303A
Cited
US3925211A
Cited
US4113628A
Cited
US4240914A
Cited
US4378324A
Cited
US4578166A
Cited
US4358378A
Cited
GB2073654A
Cited
US4370290A
Cited
EP0043265A1
Cited
US4378400A
Cited
US4460526A
Cited
US4474662A
Cited
GB2098994A
Cited
GB2101137A
Cited
GB2102333A
Cited
GB2102726A
Cited
US4440643A
Cited
US4485056A
Cited
JPS585344A
Cited
GB2104832A
Cited
US4486376A
Cited
US4528004A
Cited
JPS588512A
Cited
GB2104411A
Cited
US4474858A
Cited
GB2104905A
Cited
JPS5955313A
Cited
JPS5998704A
Cited
EP0113574A2
Cited
EP0125908A2
Cited
US4532041A
Cited
EP0132221A1
Cited
JPS59225705A
Cited
JPS6022902A
Cited
JPS6082103A
Cited
EP0141781A2
Cited
EP0143552A2
Cited
JPS60257805A
Cited
JPS61133118A
Cited
JPS61133117A
Cited
JPS61133106A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |