US4437951A — Membrane, electrochemical cell, and electrolysis …

Claim 1

Independent Claim 174 words

A membrane which is impermeable to hydraulic flow of liquid, which comprises at least two layers of fluorinated polymer which have --COOR or --S 2 W functional groups, where R is lower alkyl and W is F or Cl, adjacent said layers being in adherent contact with one another, and a web of support material embedded therein, there being at least a first said layer of polymer whose functional groups are --COOR functional groups and a second said layer of polymer whose functional groups are --COOR or --SO 2 W functional groups, each said polymer with --COOR groups having an equivalent weight of 770 to 1250, and any said polymer with --SO 2 W groups having an equivalent weight of 900 to 1400, the total thickness of said at least two layers of fluorinated polymer used in preparation of said membrane being in the range of about 50 to 250 microns, said web of support material having a thickness of about 25 to 125 microns and consisting of both reinforcing members and sacrificial members.

Claim 2

Dependent Claim 174 words

A membrane which is impermeable to hydraulic flow of liquid, which comprises at least two layers of fluorinated polymer which have --COOR or --S 2 W functional groups, where R is lower alkyl and W is F or Cl, adjacent said layers being in adherent contact with one another, and a web of support material embedded therein, there being at least a first said layer of polymer whose functional groups are --COOR functional groups and a second said layer of polymer whose functional groups are --COOR or --SO 2 W functional groups, each said polymer with --COOR groups having an equivalent weight of 770 to 1250, and any said polymer with --SO 2 W groups having an equivalent weight of 900 to 1400, the total thickness of said at least two layers of fluorinated polymer used in preparation of said membrane being in the range of about 50 to 250 microns, said web of support material having a thickness of about 25 to 125 microns and consisting of both reinforcing members and sacrificial members.

Claim 3

Dependent Claim 45 words

The membrane of claim 1 wherein said --COOR functional groups are part of --(CF 2 ) t --COOR moieties where t is 1, 2 or 3, and any said --SO 2 W functional groups are part of --CF 2 --CF 2 --SO 2 W moieties.

Claim 4

Dependent Claim 100 words

The membrane of claim 1 wherein said web of support material is a woven fabric whose reinforcing members are perhalocarbon polymer threads which are 50 to 600 denier and have an aspect ratio in the range of 2 to 20, whose sacrificial members are sacrificial threads which are 40 to 100 denier, said woven fabric having a thread count in each of the warp and weft in the range of 1.6 to 16 perhalocarbon polymer threads/cm, and a ratio of sacrificial threads to perhalocarbon polymer threads in each of the warp and weft in the range of 1:1 to 10:1.

Claim 5

Dependent Claim 45 words

The membrane of claim 3 wherein said --COOR functional groups are part of --(CF 2 ) t --COOR moieties where t is 1, 2 or 3, and any said --SO 2 W functional groups are part of --CF 2 --CF 2 --SO 2 W moieties.

Claim 6

Dependent Claim 12 words

The membrane of claim 4 wherein said layers are of perfluorinated polymers.

Claim 7

Dependent Claim 14 words

The membrane of claim 5 wherein said perhalocarbon polymer threads are perfluorocarbon polymer threads.

Claim 8

Dependent Claim 29 words

The membrane of claim 6 wherein there are two layers of said perfluorinated polymer, said second layer being of perfluorinated polymer whose functional groups are --SO 2 W groups.

Claim 9

Dependent Claim 27 words

The membrane of claim 6 wherein there are two layers of said perfluorinated polymer, said second layer being of perfluorinated polymer whose functional groups are --COOR groups.

Claim 10

Dependent Claim 39 words

The membrane of claim 6 wherein said fabric has a thickness of 50 to 100 microns, and said perfluorocarbon polymer threads are of 100 to 300 denier and have an aspect ratio in the range of 4 to 10.

Claim 11

Dependent Claim 50 words

The membrane of claim 9 wherein said fabric has a thread count in each of the warp and weft in the range of 3 to 8 perfluorocarbon polymer threads/cm, and a ratio of sacrificial threads to perfluorocarbon polymer threads in each of the warp and weft of 4:1 or 8:1.

Claim 12

Dependent Claim 14 words

The membrane of claim 10 wherein said perfluorocarbon polymer threads are monofilament of polytetrafluoroethylene.

Claim 13

Dependent Claim 54 words

The membrane of claim 11 wherein said perflurocarbon polymer threads have a substantially rectangular cross section, an aspect ratio in the range of 4 to 8, and a thickness of about 35 to 40 microns, and the ratio of sacrificial threads to perfluorocarbon polymer threads in each of the warp and weft is 4:1.

Claim 14

Dependent Claim 13 words

The membrane of claim 10 wherein each said perfluorocarbon polymer thread is multistranded.

Claim 15

Dependent Claim 60 words

The membrane of claim 10 wherein there are two layers of fluorinated polymer, said first layer having a thickness in the range of 13 to 75 microns, said second layer having a thickness in the range of 50 to 125 microns, and said total thickness of said layers of fluorinated polymer being in the range of 75 to 150 microns.

Claim 16

Dependent Claim 25 words

The membrane of claim 7, 8, 11, 12, 13 or 14 wherein said --COOR functional groups are part of --O--(CF 2 ) t --COOR moieties.

Claim 17

Dependent Claim 34 words

The membrane of claim 7, 8, 11, 12, 13 or 14 wherein t is 2 and any said --SO 2 W functional groups are part of --O--CF 2 --CF 2 --SO 2 W moieties.

Claim 18

Dependent Claim 26 words

The membrane of claim 7, 8, 11, 12, 13 or 14 wherein said woven fabric lies at least predominantly in said second layer of perfluorinated polymer.

Claim 19

Dependent Claim 21 words

The membrane of claim 7, 8, 11, 12, 13 or 14 wherein said sacrificial threads are polyester, polyamide or cellulosic threads.

Claim 20

Dependent Claim 55 words

The membrane of claim 1 wherein said web of support material is a nonwoven paper whose reinforcing members are 10 to 90% by wt. of perhalocarbon polymer fibers and whose sacrificial members are 90 to 10% by wt. of sacrificial fibers, said paper having a basis weight of about 25 to 125 g/m 2 .

Claim 21

Dependent Claim 45 words

The membrane of claim 19 wherein said --COOR functional groups are part of --(CF 2 ) t --COOR moieties where t is 1, 2 or 3, and any said --SO 2 W functional groups are part of --CF 2 --CF 2 --SO 2 W moieties.

Claim 22

Dependent Claim 12 words

The membrane of claim 19 wherein said layers are of perfluorinated polymers.

Claim 23

Dependent Claim 14 words

The membrane of claim 21 wherein said perhalocarbon polymer fibers are perfluorocarbon polymer fibers.

Claim 24

Dependent Claim 29 words

The membrane of claim 22 wherein there are two layers of said perfluorinated polymer, said second layer being of perfluorinated polymer whose functional groups are --SO 2 W groups.

Claim 25

Dependent Claim 27 words

The membrane of claim 22 wherein there are two layers of said perfluorinated polymer, said second layer being of perfluorinated polymer whose functional groups are --COOR groups.

Claim 26

Dependent Claim 28 words

The membrane of claim 22 wherein said nonwoven paper has a thickness of 50 to 75 microns and a basis weight of 25 to 50 g/m 2 .

Claim 27

Dependent Claim 24 words

The membrane of claim 25 wherein said perfluorocarbon polymer fibers are 5 to 10 denier and have a length of 3 to 20 mm.

Claim 28

Dependent Claim 26 words

The membrane of claim 26 wherein said sacrificial fibers are cellulosic kraft fibers having a freeness in the range of 500 to 700 ml Canadian Standard.

Claim 29

Dependent Claim 31 words

The membrane of claim 27 wherein said nonwoven paper consists of 25 to 75% by wt. of said perfluorocarbon polymer fibers and 75 to 25% by wt. of said kraft fibers.

Claim 30

Dependent Claim 60 words

The membrane of claim 27 wherein there are two layers of fluorinated polymer, said first layer having a thickness in the range of 13 to 75 microns, said second layer having a thickness in the range of 50 to 125 microns, and said total thickness of said layers of fluorinated polymer being in the range of 75 to 150 microns.

Claim 31

Dependent Claim 23 words

The membrane of claim 23, 24, 28 or 29 wherein said --COOR functional groups are part of --O--(CF 2 ) t --COOR moieties.

Claim 32

Dependent Claim 32 words

The membrane of claim 23, 24, 28 or 29 wherein t is 2 and any said --SO 2 W functional groups are part of --O--CF 2 --CF 2 --SO 2 W moieties.

Claim 33

Dependent Claim 24 words

The membrane of claim 23, 24, 28 or 29 wherein said nonwoven paper lies at least predominantly in said second layer of perfluorinated polymer.

Claim 34

Dependent Claim 25 words

The membrane of claim 1 wherein said membrane further comprises a gas- and liquid-permeable porous layer of electrocatalyst composition on at least one surface thereof.

Claim 35

Dependent Claim 23 words

The membrane of claim 1 wherein said membrane further comprises a gas- and liquid-permeable porous non-electrode layer on at least one surface thereof.

Claim 36

Dependent Claim 233 words

An ion exchange membrane which is impermeable to hydraulic flow of liquid, which comprises at least two layers of fluorinated polymer having --COOM or --SO 3 M functional groups, where M is H, Na, K or NH 4 , adjacent said layers being in adherent contact with one another, and a web of support material embedded therein, there being at least a first said layer of polymer whose functional groups are --COOM functional groups and a second said layer of polymer whose functional groups are --COOM or --SO 3 M functional groups, each said polymer with --COOM groups having an equivalent weight of 770 to 1250, and any said polymer with --SO 3 M groups having an equivalent weight of 900 to 1400, the total thickness of said at least two layers of fluorinated polymer, as measured on the layers of precursor polymer having --COOR or --SO 2 W functional groups where R is lower alkyl and W is F or Cl used in preparation of said membrane, being in the range of 50 to 250 microns, said web of support material having a thickness of about 25 to 125 microns and an openness of at least 50% and consisting of reinforcing members, said reinforcing members defining window areas therebetween, and channels in said membrane extending from said window areas to blind areas where said reinforcing members are proximate to said first layer.

Claim 37

Dependent Claim 233 words

An ion exchange membrane which is impermeable to hydraulic flow of liquid, which comprises at least two layers of fluorinated polymer having --COOM or --SO 3 M functional groups, where M is H, Na, K or NH 4 , adjacent said layers being in adherent contact with one another, and a web of support material embedded therein, there being at least a first said layer of polymer whose functional groups are --COOM functional groups and a second said layer of polymer whose functional groups are --COOM or --SO 3 M functional groups, each said polymer with --COOM groups having an equivalent weight of 770 to 1250, and any said polymer with --SO 3 M groups having an equivalent weight of 900 to 1400, the total thickness of said at least two layers of fluorinated polymer, as measured on the layers of precursor polymer having --COOR or --SO 2 W functional groups where R is lower alkyl and W is F or Cl used in preparation of said membrane, being in the range of 50 to 250 microns, said web of support material having a thickness of about 25 to 125 microns and an openness of at least 50% and consisting of reinforcing members, said reinforcing members defining window areas therebetween, and channels in said membrane extending from said window areas to blind areas where said reinforcing members are proximate to said first layer.

Claim 38

Dependent Claim 18 words

The membrane of claim 35 wherein said channels are open to the exposed surface of said second layer.

Claim 39

Dependent Claim 45 words

The membrane of claim 35 wherein said --COOM functional groups are part of --(CF 2 ) t --COOM moieties where t is 1, 2 or 3, and any said --SO 3 M functional groups are part of --CF 2 --CF 2 --SO 3 M moieties.

Claim 40

Dependent Claim 108 words

The membrane of claim 35 wherein said web of support material is a fabric whose reinforcing members are perhalocarbon polymer threads which are 50 to 600 denier and have an aspect ratio in the range of 2 to 20, said fabric having a thread count in each of the warp and weft in the range of 1.6 to 16 perhalocarbon polymer threads/cm, said threads in the warp meeting said threads in the weft at junctions, each adjacent pair of junctions defining a thread segment, there being at least one said channel extending from a window area to said blind areas adjacent at least half of said thread segments.

Claim 41

Dependent Claim 45 words

The membrane of claim 38 wherein said --COOM functional groups are part of --(CF 2 ) t --COOM moieties where t is 1, 2 or 3, and any said --SO 3 M functional groups are part of --CF 2 --CF 2 --SO 3 M moieties.

Claim 42

Dependent Claim 28 words

The membrane of claim 39 wherein there is at least one said channel extending from a window area to said blind areas adjacent all of said thread segments.

Claim 43

Dependent Claim 12 words

The membrane of claim 40 wherein said layers are of perfluorinated polymers.

Claim 44

Dependent Claim 14 words

The membrane of claim 41 wherein said perhalocarbon polymer threads are perfluorocarbon polymer threads.

Claim 45

Dependent Claim 29 words

The membrane of claim 42 wherein there are two layers of said perfluorinated polymer, said second layer being of perfluorinated polymer whose functional groups are --SO 3 M groups.

Claim 46

Dependent Claim 27 words

The membrane of claim 42 wherein there are two layers of said perfluorinated polymer, said second layer being of perfluorinated polymer whose functional groups are --COOM groups.

Claim 47

Dependent Claim 39 words

The membrane of claim 42 wherein said fabric has a thickness of 50 to 100 microns, and said perfluorocarbon polymer threads are of 100 to 300 denier and have an aspect ratio in the range of 4 to 10.

Claim 48

Dependent Claim 29 words

The membrane of claim 45 wherein said fabric has a thread count in each of the warp and weft in the range of 3 to 8 perfluorocarbon polymer threads/cm.

Claim 49

Dependent Claim 14 words

The membrane of claim 46 wherein said perfluorocarbon polymer threads are monofilament of polytetrafluoroethylene.

Claim 50

Dependent Claim 35 words

The membrane of claim 47 wherein said perfluorocarbon polymer threads have a substantially rectangular cross section, an aspect ratio in the range of 4 to 8, and a thickness of about 35 to 40 microns.

Claim 51

Dependent Claim 13 words

The membrane of claim 46 wherein each said perfluorocarbon polymer thread is multistranded.

Claim 52

Dependent Claim 73 words

The membrane of claim 46 wherein there are two layers of said perfluorinated polymer, said --COOM groups are part of --O--(CF 2 ) t --COOM moieties, said first layer having a thickness in the range of 13 to 75 microns, said second layer having a thickness in the range of 50 to 125 microns, and said total thickness of said layers of fluorinated polymer being in the range of 75 to 150 microns.

Claim 53

Dependent Claim 18 words

The membrane of claim 50 wherein said channels are open to the exposed surface of said second layer.

Claim 54

Dependent Claim 17 words

The membrane of claim 46 wherein said channels have a nominal diameter of 10 to 50 microns.

Claim 55

Dependent Claim 25 words

The membrane of claim 43, 44, 47, 48, 49 or 50 wherein said --COOR functional groups are part of --O--(CF 2 ) t --COOR moieties.

Claim 56

Dependent Claim 34 words

The membrane of claim 43, 44, 47, 48, 49 or 50 wherein t is 2 and any said --SO 3 M functional groups are part of --O--CF 2 --CF 2 --SO 3 M moieties.

Claim 57

Dependent Claim 25 words

The membrane of claim 43, 44, 47, 48, 49 or 50 wherein said fabric lies at least predominantly in said second layer of fluorinated polymer.

Claim 58

Dependent Claim 35 words

The membrane of claim 35 wherein said web of support material is a nonwoven paper whose reinforcing members are perhalocarbon polymer fibers and which has a basis weight of 2.5 to 112.5 g/m 2 .

Claim 59

Dependent Claim 45 words

The membrane of claim 56 wherein said --COOM functional groups are part of --(CF 2 ) t --COOM moieties where t is 1, 2 or 3, and any said --SO 3 M functional groups are part of --CF 2 --CF 2 --SO 3 M moieties.

Claim 60

Dependent Claim 12 words

The membrane of claim 57 wherein said layers are of perfluorinated polymers.

Claim 61

Dependent Claim 14 words

The membrane of claim 58 wherein said perhalocarbon polymer fibers are perfluorocarbon polymer fibers.

Claim 62

Dependent Claim 29 words

The membrane of claim 59 wherein there are two layers of said perfluorinated polymer, said second layer being of perfluorinated polymer whose functional groups are --SO 3 M groups.

Claim 63

Dependent Claim 27 words

The membrane of claim 59 wherein there are two layers of said perfluorinated polymer, said second layer being of perfluorinated polymer whose functional groups are --COOM groups.

Claim 64

Dependent Claim 28 words

The membrane of claim 59 wherein said nonwoven paper has a thickness of 50 to 75 microns and a basis weight of 2.5 to 45 g/m 2 .

Claim 65

Dependent Claim 24 words

The membrane of claim 60 wherein said perfluorocarbon polymer fibers are 5 to 10 denier and have a length of 3 to 20 mm.

Claim 66

Dependent Claim 73 words

The membrane of claim 60 wherein there are two layers of said perfluorinated polymer, said --COOM groups are part of --O--(CF 2 ) t --COOM moieties, said first layer having a thickness in the range of 13 to 75 microns, said second layer having a thickness in the range of 50 to 125 microns, and said total thickness of said layers of fluorinated polymer being in the range of 75 to 150 microns.

Claim 67

Dependent Claim 16 words

The membrane of claim 61 wherein said channels have nominal diameters of 1 to 20 microns.

Claim 68

Dependent Claim 23 words

The membrane of claim 60, 61, 64 or 65 wherein said --COOR functional groups are part of --O--(CF 2 ) t --COOR moieties.

Claim 69

Dependent Claim 32 words

The membrane of claim 60, 61, 64 or 65 wherein t is 2 and any said --SO 3 M functional groups are part of --O--CF 2 --CF 2 --SO 3 M moieties.

Claim 70

Dependent Claim 24 words

The membrane of claim 60, 61, 64 or 65 wherein said nonwoven paper lies at least predominantly in said second layer of perfluorinated polymer.

Claim 71

Dependent Claim 25 words

The membrane of claim 35 wherein said membrane further comprises a gas- and liquid-permeable porous layer of electrocatalyst composition on at least one surface thereof.

Claim 72

Dependent Claim 23 words

The membrane of claim 35 wherein said membrane further comprises a gas- and liquid-permeable porous non-electrode layer on at least one surface thereof.

Claim 73

Dependent Claim 44 words

The membrane of claim 50 wherein said membrane further comprises a gas- and liquid-permeable porous layer of cathodic electrocatalyst composition on the exposed surface of said first layer, and a gas- and liquid-permeable porous non-electrode layer on the exposed surface of said second layer.

Claim 74

Dependent Claim 44 words

An electrochemical cell which comprises an anode compartment, an anode situated within said anode compartment, a cathode compartment, a cathode situated within said cathode compartment, and, between said compartments, said membrane of claim 35, 38, 43, 44, 48, 50, 56, 64, 59 or 70.

Claim 75

Dependent Claim 22 words

The electrochemical cell of claim 72 wherein the spacing between said anode and said cathode is no greater than about 3 mm.

Claim 76

Dependent Claim 22 words

The electrochemical cell of claim 73 wherein said membrane is in contact with at least one of said anode and said cathode.

Claim 77

Dependent Claim 19 words

The electrochemical cell of claim 74 wherein said membrane is in contact with both said anode and said cathode.

Claim 78

Dependent Claim 61 words

In a process for electrolysis of brine in a chloralkali cell which comprises an anode, an anode compartment, a cathode, a cathode compartment, and a fluorine-containing cation exchange membrane which separates said compartments, to form caustic and chlorine, the improvement which comprises employing as said membrane the membrane of claim 35, 38, 43, 44, 48, 50, 56, 64, 59 or 70.

Claim 79

Dependent Claim 21 words

The process of claim 76 wherein the spacing between said anode and said cathode is no greater than about 3 mm.

Claim 80

Dependent Claim 21 words

The process of claim 77 wherein said membrane is in contact with at least one of said anode and said cathode.

Claim 81

Dependent Claim 18 words

The process of claim 78 wherein said membrane is in contact with both said anode and said cathode.

Claim 82

Dependent Claim 12 words

The membrane of claim 18 wherein said sacrificial threads are cellulosic threads.

Claim 83

Dependent Claim 12 words

The membrane of claim 18 wherein said sacrificial threads are polyester threads.

Claim 84

Dependent Claim 22 words

The membrane of claim 81 wherein said membrane comprises a gas- and liquid-permeable porous non-electrode layer on at least one surface thereof.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1987-03-20	1987-09-19	1988-03-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1991-03-20	1991-09-19	1992-03-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1995-03-20	1995-09-19	1996-03-20	$7700.00	Window Closed / Lapsed

Membrane, electrochemical cell, and electrolysis process

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