US4657564A
Expired / Lapsed
US
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Fluorinated polymeric membranes for gas separation processes
Assignee: Air Products and Chemicals Inc
•
Filing: 1985-12-13
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Granted: 1987-04-14
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Expires: 2005-12-13
Abstract
Abstract The present invention is a treated, semi-permeable, polymeric membrane having improved selectivity for separating components of a gas mixture. The membrane is provided by fluorinating a polymer cast into membrane form, having the general structural formula: <IMAGE> wherein R1 is a linear or branched C1-C4 alkyl group; R2 and R3 are independently linear or branched C1-C6 alkyl groups; R4 is a linear or branched C1-C12 alkyl or aryl group; X is a C1-C3 alkyl group or <IMAGE> m is at least 100; and n is 0 or 1.
Inventors
- 👤 Michael Langsam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:43
CPC Classifications
B; B01; B01D; B01D71/00; B01D67/00; B01D67/0081; B01D67/0093; B01D71/06; B01D71/44; C; C08; C08F; C08F8/00; C08F8/18; C08F8/20; C08F8/22; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31645; Y10T428/31649
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
159 words
A process for separating a feed gas mixture containing at least two components, said process comprising bringing said feed gas mixture into contact with a treated, semi-permeable, polymeric membrane comprising a polymer, cast into membrane form, having the general structural formula: ##STR11## wherein R 1 is a linear or branched C 1 -C 4 alkyl group; R 2 and R 3 are independently linear or branched C 1 -C 6 alkyl groups; R 4 is a linear or branched C 1 -C 12 alkyl or aryl group; X is a C 1 -C 3 alkyl group or ##STR12## m is at least 100; and n is 0 or 1, which has been treated with a reactive source of fluorine for a time sufficient to modify the membrane such that the O 2 /N 2 selectivity ratio of the membrane is increased by at least 50% over that of the membrane prior to treatment with the reactive elemental fluorine source.
Claim 2
Dependent Claim
159 words
A process for separating a feed gas mixture containing at least two components, said process comprising bringing said feed gas mixture into contact with a treated, semi-permeable, polymeric membrane comprising a polymer, cast into membrane form, having the general structural formula: ##STR11## wherein R 1 is a linear or branched C 1 -C 4 alkyl group; R 2 and R 3 are independently linear or branched C 1 -C 6 alkyl groups; R 4 is a linear or branched C 1 -C 12 alkyl or aryl group; X is a C 1 -C 3 alkyl group or ##STR12## m is at least 100; and n is 0 or 1, which has been treated with a reactive source of fluorine for a time sufficient to modify the membrane such that the O 2 /N 2 selectivity ratio of the membrane is increased by at least 50% over that of the membrane prior to treatment with the reactive elemental fluorine source.
Claim 3
Dependent Claim
22 words
A process in accordance with claim 1 wherein the reactive elemental fluorine source is a gas stream containing between 0.01-25% fluorine gas.
Claim 4
Dependent Claim
22 words
A process in accordance with claim 2 wherein the reactive elemental fluorine source is a gas stream containing between 0.1-2% fluorine gas.
Claim 5
Dependent Claim
34 words
A process in accordance with claim 1 wherein said treated, semi-permeable, polymeric membrane has been contacted with a reactive source of elemental fluorine for a period of time between 10 seconds and 24 hours.
Claim 6
Dependent Claim
34 words
A process in accordance with claim 4 wherein said treated, semi-permeable, polymeric membrane has been contacted with a reactive source of elemental fluorine for a period of time between 0.5 min and 120 min.
Claim 7
Dependent Claim
35 words
A process in accordance with claim 1 wherein said feed gas mixture is brought into contact with a treated, semi-permeable, polymeric membrane comprising a polymer, cast into membrane form, having a structural formula wherein n=0.
Claim 8
Dependent Claim
60 words
A process in accordance with claim 6 wherein said feed gas mixture is brought into contact with a treated, semi-permeable, polymeric membrane comprising a polymer, cast into membrane form, having a structural formula wherein R 1 , R 2 and R 3 are CH 3 groups and R 4 is a linear or branched C 1 -C 12 alkyl group.
Claim 9
Dependent Claim
40 words
A process in accordance with claim 7 wherein said feed gas mixture is brought into contact with a treated, semi-permeable, polymeric membrane comprising a polymer, cast into membrane form, having the structural formula: ##STR13## wherein m is at least 100.
Claim 10
Dependent Claim
50 words
A process in accordance with claim 1 wherein the feed gas mixture is selected from the group consisting of: O 2 /N 2 , He/CH 4 , H 2 /CH 4 , H 2 /CO, CO 2 /CH 4 , CO 2 /N 2 and H 2 /N 2 .
Claim 11
Dependent Claim
150 words
A treated, semi-permeable, polymeric membrane having improved selectivity for use in separating components of a feed gas mixture, said membrane comprising a polymer, cast into membrane form, having the general structural formula: ##STR14## wherein R 1 is a linear or branched C 1 -C 4 alkyl group; R 2 and R 3 are independently linear or branched C 1 -C 6 alkyl groups; R 4 is a linear or branched C 1 -C 12 alkyl or aryl group; X is a C 1 -C 3 alkyl group or ##STR15## m is at least 100; and n is 0 or 1, which has been treated with a reactive source of flourine for a time sufficient to modify the membrane such that the O 2 /N 2 selectivity ratio of the membrane is increased by at least 50% over that of the membrane prior to treatment with the reactive elemental fluorine source.
Claim 12
Dependent Claim
150 words
A treated, semi-permeable, polymeric membrane having improved selectivity for use in separating components of a feed gas mixture, said membrane comprising a polymer, cast into membrane form, having the general structural formula: ##STR14## wherein R 1 is a linear or branched C 1 -C 4 alkyl group; R 2 and R 3 are independently linear or branched C 1 -C 6 alkyl groups; R 4 is a linear or branched C 1 -C 12 alkyl or aryl group; X is a C 1 -C 3 alkyl group or ##STR15## m is at least 100; and n is 0 or 1, which has been treated with a reactive source of flourine for a time sufficient to modify the membrane such that the O 2 /N 2 selectivity ratio of the membrane is increased by at least 50% over that of the membrane prior to treatment with the reactive elemental fluorine source.
Claim 13
Dependent Claim
25 words
A treated, semi-permeable, polymeric membrane in accordance with claim 10 wherein the reactive elemental fluorine source is a gas stream containing between 0.01-25% fluorine gas.
Claim 14
Dependent Claim
25 words
A treated, semi-permeable, polymeric membrane in accordance with claim 11 wherein the reactive elemental fluorine source is a gas stream containing between 0.1-2% fluorine gas.
Claim 15
Dependent Claim
32 words
A trreated, semi-permeable, polymeric membrane in accordance with claim 10 which has been contacted with a reactive source of elemental fluorine for a period of time between 10 seconds and 24 hours.
Claim 16
Dependent Claim
32 words
A treated, semi-permeable, polymeric membrane in accordance with claim 13 which has been contacted with a reactive source of elemental fluorine for a period of time between 0.5 min and 120 min.
Claim 17
Dependent Claim
23 words
A treated, semi-permeable, polymeric membrane in accordance with claim 10 wherein said polymer cast into membrane form has a structural formula wherein n=0.
Claim 18
Dependent Claim
48 words
A treated, semi-permeable, polymeric membrane in accordance with claim 10 wherein said polymer cast into membrane form has a structural formula wherein R 1 , R 2 and R 3 are CH 3 groups and R 4 is a linear or branched C 1 -C 12 alkyl group.
Claim 19
Dependent Claim
23 words
A treated, semi-permeable, polymeric membrane in accordance with claim 16 wherein said polymer cast into membrane form has a structural formula wherein n=0.
Claim 20
Dependent Claim
30 words
A treated, semi-permeable, polymeric membrane in accordance with claim 10 in which the polymer cast into membrane form has the following structural formula: ##STR16## wherein m is at least 100.
Claim 21
Dependent Claim
28 words
A membrane in accordance with claim 10 wherein the polymer is cast into the form of an asymmetric membrane having a thin dense layer over a porous layer.
Claim 22
Dependent Claim
30 words
A membrane in accordance with claim 10 wherein the polymer, prior to treatment with a reactive source of elemental fluorine, is first coated onto the surface of a porous substrate.
Claim 23
Dependent Claim
26 words
A membrane in accordance with claim 20 wherein the porous substrate is in the form of a flat sheet or hollow fiber prior to being coated.
Claim 24
Dependent Claim
14 words
A membrane in accordance with claim 20 wherein the porous substrate is a polyolefin.
Claim 25
Dependent Claim
15 words
A membrane in accordance with claim 20 wherein the porous substrate is polyethylene or polypropylene.
Claim 26
Independent Claim
158 words
A method of producing a semi-permeable, polymeric membrane having improved selectivity for use in separating components of a feed gas mixture, said method comprising: (1) casting into membrane form a polymer having the general structural formula: ##STR17## wherein R 1 is a linear or branched C 1 -C 4 alkyl group; R 2 and R 3 are independently linear or branched C 1 -C 6 alkyl groups; R 4 is a linear or branched C 1 -C 12 alkyl or aryl group; X is a C 1 -C 3 alkyl group or ##STR18## m is at least 100; and n is 0 or 1; and (2) treating said polymer in membrane form with a reactive source of fluorine for a time sufficient to modify the membrane such that the O 2 /N 2 selectivity ratio of the membrane is increased by at least 50% over that of the membrane prior to treatment with the reactive elemental fluorine source.
Claim 27
Independent Claim
158 words
A method of producing a semi-permeable, polymeric membrane having improved selectivity for use in separating components of a feed gas mixture, said method comprising: (1) casting into membrane form a polymer having the general structural formula: ##STR17## wherein R 1 is a linear or branched C 1 -C 4 alkyl group; R 2 and R 3 are independently linear or branched C 1 -C 6 alkyl groups; R 4 is a linear or branched C 1 -C 12 alkyl or aryl group; X is a C 1 -C 3 alkyl group or ##STR18## m is at least 100; and n is 0 or 1; and (2) treating said polymer in membrane form with a reactive source of fluorine for a time sufficient to modify the membrane such that the O 2 /N 2 selectivity ratio of the membrane is increased by at least 50% over that of the membrane prior to treatment with the reactive elemental fluorine source.
Claim 28
Dependent Claim
23 words
A method in accordance with claim 24 wherein the reactive source of elemental fluorine is a gas stream containing between 0.01-25% fluorine gas.
Claim 29
Dependent Claim
33 words
A method in accordance with claim 25 wherein the polymer in membrane form is treated with a reactive source of elemental fluorine for a period of time between 10 seconds and 24 hours.
Claim 30
Dependent Claim
47 words
A method in accordance with claim 24 wherein the polymer cast into membrane form has the general structural formula wherein R 1 , R 2 and R 3 are CH 3 groups, R 4 is a linear or branched C 1 -C 12 alkyl group and n=0.
Claim 31
Dependent Claim
26 words
A method in accordance with claim 24 wherein the polymer cast into membrane form has the following structural formula: ##STR19## wherein m is at least 100.
Claim 32
Dependent Claim
29 words
A method in accordance with claim 24 wherein said polymer in membrane form is treated with a reactive source of elemental fluorine under ambient conditions of temperature and pressure.
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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) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |