US4657564A — Fluorinated polymeric membranes for gas separatio…

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.

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

Fluorinated polymeric membranes for gas separation processes

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