US4437952A
Expired / Lapsed
US
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Coextruded multilayer cation exchange membranes
Assignee: EIDP Inc
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Filing: 1982-10-25
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Granted: 1984-03-20
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Expires: 2002-10-25
Abstract
Abstract Multilayer fluorinated cation exchange membranes prepared by coextrusion of precursor polymers.
Inventors
- 👤 Roger A. Smith
- 👤 Michael S. Withers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:39
CPC Classifications
C; C25; C25B; C25B13/00; C25B13/02; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2275; C08J5/2281; C08J2327/00; C08J2327/02; C08J2327/12
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
96 words
A process for the preparation of a multilayer cationic ion exchange membrane by heating at least two substantially incompatible melt-fabricable fluorinated polymers containing pendant side chains having functional groups selected from sulfonyl and carboxyl to a temperature above the melting point of the polymers, bringing the molten polymers into contact while each is at a temperature above the melting point of the polymer, coextruding the polymers into a composite film, cooling the resulting composite to a temperature below the melting points of each of the films, and subsequently converting the functional groups to ionizable functional groups.
Claim 2
Dependent Claim
96 words
A process for the preparation of a multilayer cationic ion exchange membrane by heating at least two substantially incompatible melt-fabricable fluorinated polymers containing pendant side chains having functional groups selected from sulfonyl and carboxyl to a temperature above the melting point of the polymers, bringing the molten polymers into contact while each is at a temperature above the melting point of the polymer, coextruding the polymers into a composite film, cooling the resulting composite to a temperature below the melting points of each of the films, and subsequently converting the functional groups to ionizable functional groups.
Claim 3
Dependent Claim
10 words
A process of claim 1 wherein two polymers are extruded.
Claim 4
Dependent Claim
20 words
A process of claim 2 wherein one polymer contains sulfonyl functional groups and the other polymer contains carboxylic functional groups.
Claim 5
Dependent Claim
21 words
A process of claim 2 wherein both polymers contain sulfonyl functional groups and differ in equivalent weight by at least 200.
Claim 6
Dependent Claim
18 words
A process of claim 1 wherein the extrusion temperature is maintained at about from 260 to 330° C.
Claim 7
Dependent Claim
22 words
A process of claim 1 wherein the multilayer membrane is extruded to a total thickness of about from 25 to 250 microns.
Claim 8
Dependent Claim
21 words
A process of claim 6 wherein the multilayer membrane is extruded to a thickness of about from 75 to 150 microns.
Claim 9
Dependent Claim
24 words
A process of claim 1 wherein the composite is laminated to a reinforcing web prior to converting the functional groups to ionizable functional groups.
Claim 10
Dependent Claim
12 words
A coextruded cation exchange membrane resulting from the process of claim 1.
Claim 11
Dependent Claim
12 words
A coextruded cation exchange membrane resulting from the process of claim 8.
Claim 12
Dependent Claim
83 words
In a process for the continuous production of alkali metal hydroxide which comprises continuously providing an aqueous alkali metal halide solution to the anode compartment of an electrolytic cell having an anode, a cathode, and a cation exchange membrane separating the anode and the cathode; electrolyzing the solution; and continuously removing alkali metal hydroxide solution, hydrogen, and halogen from the electrolytic cell, the improvement wherein the exchange membrane consists essentially of a coextruded cation exchange membrane resulting from the process of claim 1.
Claim 13
Dependent Claim
42 words
In an electrolytic cell having an anode, a cathode, and a cation exchange membrane separating the anode and the cathode, the improvement wherein the cation exchange membrane consists essentially of a coextruded cation exchange membrane resulting from the process of claim 1.
Claim 14
Dependent Claim
22 words
An electrolytic cell of claim 12 wherein the gap between the anode and the cathode is no greater than about 3 mm.
Claim 15
Dependent Claim
23 words
An electrolytic cell of claim 13 wherein the cation exchange membrane is in contact with at least one of the anode and cathode.
Claim 16
Dependent Claim
29 words
A process of claim 1 further comprising applying to at least one surface of the multilayered cationic ion exchange membrane a gas- and liquid-permeable porous layer of electrocatalyst composition.
Claim 17
Dependent Claim
27 words
A process of claim 1 further comprising applying to at least one surface of the multilayered cationic ion exchange membrane a gas- and liquid-permeable porous non-electrode layer.
Claim 18
Dependent Claim
36 words
A process of claim 1 further comprising applying to at least one surface of the resulting multilayered cationic ion exchange membrane at least one gas- and liquid-permeable porous layer selected from electrocatalyst composition and non-electrode material.
Claim 19
Dependent Claim
29 words
A process of claim 1 further comprising embossing at least one surface of the resulting multilayered cationic ion exchange membrane to provide a surface roughness of about 2-5 microns.
Claim 20
Dependent Claim
25 words
A process of claim 16 wherein the gas and liquid permeable porous non-electrode layer is applied as a dispersion of inorganic compound in a binder.
Claim 21
Dependent Claim
12 words
A process of claim 19 wherein the binder is a fluorocarbon polymer.
Claim 22
Dependent Claim
27 words
A process of claim 20 wherein the inorganic component is selected from the group consisting of tin oxide, titanium oxide, zirconium oxide, nickel oxide and iron oxide.
Claim 23
Dependent Claim
14 words
A process of claim 21 wherein the inorganic component consists essentially of zirconium oxide.
Claim 24
Dependent Claim
16 words
A process of claim 20 wherein at least the surface of the fluorocarbon polymer is hydrophilic.
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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) | 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 |