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US4994095A
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Semipermeable membranes based on specific 4,4'-(1H-alkylidene)bis[2,3,6-trialkylphenol]type polyesters
Assignee: Praxair Technology Inc
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Filing: 1989-12-05
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Granted: 1991-02-19
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Expires: 2009-12-05
Abstract
Abstract Permeable membranes comprised predominantly of specifically defined polyester of 4,4'-(1H-alkylidene)bis[2,3,6-trialkylphenol] and aromatic dicarboxylic acids. The invention also pertains to the novel permeation processes for recovery of an oxygen/nitrogen or carbon dioxide/methane or helium/methane component from a mixture of said component with other components in the mixture.
Inventors
- 👤 James H. Kawakami
- 👤 Natarajan Muruganandam
- 👤 George L. Brode
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:48
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/68; C08G63/682; C08G63/6824; C08G63/6826; B; B01; B01D; B01D71/00; B01D71/06; B01D71/48; B01D71/481
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
91 words
A gas separation membrane comprising a thin layer consisting predominantly of a polyester or copolyester derived essentially from the reaction of an aromatic dicarboxylic acid or derivative thereof and a 4,4'-(1H-alkylidene)bis[2,3,6-trialkylphenol] of the general formula: ##STR10## wherein R is an alkyl group having from 1 to about 3 carbon atoms and R' is an alkyl group having from 1 to about 4 carbon atoms; said membrane having a combination of high selectivity and high permeation rate values for O 2 /N 2 , CO 2 /CH 4 and He/CH 4 separations.
Claim 2
Dependent Claim
91 words
A gas separation membrane comprising a thin layer consisting predominantly of a polyester or copolyester derived essentially from the reaction of an aromatic dicarboxylic acid or derivative thereof and a 4,4'-(1H-alkylidene)bis[2,3,6-trialkylphenol] of the general formula: ##STR10## wherein R is an alkyl group having from 1 to about 3 carbon atoms and R' is an alkyl group having from 1 to about 4 carbon atoms; said membrane having a combination of high selectivity and high permeation rate values for O 2 /N 2 , CO 2 /CH 4 and He/CH 4 separations.
Claim 3
Dependent Claim
15 words
A gas separation membrane as claimed in claim 1 wherein R and R' are methyl.
Claim 4
Dependent Claim
28 words
A gas separation membrane as claimed in claim 1 wherein said aromatic dicarboxylic acid comprises isophthalic acid or derivative thereof, terephthalic acid or derivative thereof, or mixtures thereof.
Claim 5
Dependent Claim
28 words
A gas separation membrane as claimed in claim 2 wherein said aromatic dicarboxylic acid comprises isophthalic acid or derivative thereof, terephthalic acid or derivative thereof, or mixtures thereof.
Claim 6
Dependent Claim
17 words
A gas separation membrane as claimed in claim 2 wherein said aromatic dicarboxylic acid is terephthalic acid.
Claim 7
Dependent Claim
17 words
A gas separation membrane as claimed in claim 2 wherein said aromatic dicarboxylic acid is isophthalic acid.
Claim 8
Dependent Claim
17 words
A gas separation membrane as claimed in claim 2 wherein said aromatic carboxylic acid is 4-bromoisophthalic acid.
Claim 9
Dependent Claim
17 words
A gas separation membrane as claimed in claim 2 wherein said aromatic dicarboxylic acid is 2-bromoterephthalic acid.
Claim 10
Dependent Claim
23 words
A gas separation membrane as claimed in claim 2 wherein said aromatic dicarboxylic acid is a mixture of 4-bromoisophthalic acid and 2-bromoterephthalic acid.
Claim 11
Dependent Claim
17 words
A gas separation membrane as claimed in claim 2 wherein said aromatic dicarboxylic acid is a mixture.
Claim 12
Dependent Claim
34 words
A gas separation membrane as claimed in claim 2 wherein said aromatic dicarboxylic acid is a mixture of (i) isophthalic acid or derivative thereof and (ii) 4-bromoisophthalic acid or 2-bromoterephthalic acid or mixture thereof.
Claim 13
Dependent Claim
34 words
A gas separation membrane as claimed in claim 2 wherein said aromatic dicarboxylic acid is a mixture of (i) terephthalic acid or derivative thereof and (ii) 4-bromoisophthalic acid or 2-bromoterephthalic acid or mixture thereof.
Claim 14
Dependent Claim
134 words
A process for separating a component from an O 2 /N, CO 2 /CH 4 or He/CH 4 gas mixture containing said component which comprises contacting said gas mixture with one side of a gas separation membrane comprising a thin layer consisting predominantly of a polyester or copolyester derived from the reaction of a 4,4'-(1H-alkylidene) bis[2,3,6-trialkylphenol] of the general formula: ##STR11## wherein R is an alkyl group having from 1 to about 3 carbon atoms and R' is an alkyl group having from 1 to about 4 carbon atoms, and an aromatic dicarboxylic acid or derivative thereof; said membrane having a combination of high selectivity and high permeation rate values, while maintaining a pressure differential across the two sides of the membrane and removing the permeated component from the other side of the membrane.
Claim 15
Dependent Claim
134 words
A process for separating a component from an O 2 /N, CO 2 /CH 4 or He/CH 4 gas mixture containing said component which comprises contacting said gas mixture with one side of a gas separation membrane comprising a thin layer consisting predominantly of a polyester or copolyester derived from the reaction of a 4,4'-(1H-alkylidene) bis[2,3,6-trialkylphenol] of the general formula: ##STR11## wherein R is an alkyl group having from 1 to about 3 carbon atoms and R' is an alkyl group having from 1 to about 4 carbon atoms, and an aromatic dicarboxylic acid or derivative thereof; said membrane having a combination of high selectivity and high permeation rate values, while maintaining a pressure differential across the two sides of the membrane and removing the permeated component from the other side of the membrane.
Claim 16
Dependent Claim
13 words
A process as claimed in claim 13 wherein R and R' are methyl.
Claim 17
Dependent Claim
15 words
A process as claimed in claim 14 wherein said gas mixture comprises oxygen and nitrogen.
Claim 18
Dependent Claim
13 words
A process as claimed in claim 14 wherein said gas mixture comprises air.
Claim 19
Dependent Claim
16 words
A process as claimed in claim 14 wherein said gas mixture comprises carbon dioxide and methane.
Claim 20
Dependent Claim
15 words
A process as claimed in claim 14 wherein said gas mixture comprises helium and methane.
Claim 21
Dependent Claim
26 words
A process as claimed in claim 13 wherein said aromatic dicarboxylic acid comprises isophthalic acid or derivative thereof, terephthalic acid or derivative thereof, or mixtures thereof.
Claim 22
Dependent Claim
26 words
A process as claimed in claim 14 wherein said aromatic dicarboxylic acid comprises isophthalic acid or derivative thereof, terephthalic acid or derivative thereof, or mixtures thereof.
Claim 23
Dependent Claim
15 words
A process as claimed in claim 14 wherein said aromatic dicarboxylic acid is terephthalic acid.
Claim 24
Dependent Claim
15 words
A process as claimed in claim 14 wherein said aromatic dicarboxylic acid is isophthalic acid.
Claim 25
Dependent Claim
15 words
A process as claimed in claim 14 wherein said aromatic dicarboxylic acid is 4-bromoisophthalic acid.
Claim 26
Dependent Claim
15 words
A process as claimed in claim 14 wherein said aromatic dicarboxylic acid is 2-bromoterephthalic acid.
Claim 27
Dependent Claim
21 words
A process as claimed in claim 14 wherein said aromatic dicarboxylic acid is a mixture of 4-bromoisophthalic acid and 2-bromoterephthalic acid.
Claim 28
Dependent Claim
32 words
A process as claimed in claim 14 wherein said aromatic dicarboxylic acid is a mixture of (i) isophthalic acid or derivative thereof and (ii) 4-bromoisophthalic acid or 2-bromoterephthalic acid or mixture thereof.
Claim 29
Dependent Claim
32 words
A process as claimed in claim 14 wherein said aromatic dicarboxylic acid is a mixture of (i) terephthalic acid or derivative thereof and (ii) 4-bromoisophthalic acid or 2-bromoterephthalic acid or mixture thereof.
Claim 30
Dependent Claim
46 words
A polyester gas separation membrane as claimed in claim 1 wherein the predominant recurring unit of said polyester has the structural formula: ##STR12## wherein R and R' are as defined in claim 1 and x is an integer having a value of at least about 20.
Claim 31
Dependent Claim
43 words
A process as claimed in claim 13 wherein the predominant recurring unit of said polyester has the structural formula: ##STR13## wherein R and R' are as defined in claim 13 and x is an integer having a value of at least about 20.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-02-18 | 1994-08-20 | 1995-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-18 | 1998-08-20 | 1999-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-18 | 2002-08-20 | 2003-02-19 | $7700.00 | Window Closed / Lapsed |