US3926864A
Expired / Lapsed
US
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Ion exchange membranes having a macroporous surface area
Assignee: Veolia WTS Systems USA Inc
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Filing: 1973-02-20
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Granted: 1975-12-16
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Expires: 1993-02-20
Abstract
Abstract This invention is directed to electrodialysis equipment particularly to components comprising the ion exchange membranes. These membranes are fabricated with a polymeric macroporous surface as contrasted to the prior art microporous ''''gel'''' type membranes. The macroporous membrane surface or layer lessens the tendency for membranes especially the anion selective type to foul when employed in the electrodialysis of solutions containing fouling constituents. The macroporous membranes are obtaining by polymerizing the liquid monomers in the presence of a nonpolymerizable solvent pair or diluent comprised of both a ''''good'''' and a ''''poor'''' solvent, said solvent characterized with respect to the solvents ability to swell the cross-linked polymer that is formed.
Inventors
- 👤 Jr Russell B Hodgdon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:10
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0006; B01D61/00; B01D61/42; B01D61/44; B01D61/46; C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; H; H01; H01M; H01M50/00; H01M50/40; H01M50/409; H01M50/411; H01M50/414; H01M50/489; H01M50/491; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
198 words
A METHOD OF PREPARING A SUBSTANTIALLY INSOLUBLE CROSSLINKED, POLYMERIC NON-LAMINATED, ONE PIECE BOARD SUITABLE FOR THE MANUFACTURE OF ION-SELECTIVE MEMBRANES, THE BOARDS HAVING AT LEAST TWO DIMENSIONS IN EXCESS OF ONE CENTIMETER WITH BOTH MAJOR SURFACES HAVING A MACROPOROUS STRUCTURE OF PORE DIAMETER SIZES BETWEEN ABOUT 500-1500 ANGSTROMS WITH THE INTERIOR PORTION OF SAID BOARDS SUBSTANTIALLY COMPRISIG A MICROPOROUS STRUCTURE HAVING PORE DIAMETER SIZES IN THE RANGE OF ABOUT 10-30 ANGSTROMS, THE METHOD COMPRISING PREPARING A MONOMERIC MIXTURE OF AT LEAST ONE MONOVINYL AROMATIC MONOMER AND AT LEAST ONE POLYVINYL AROMATIC CROSS-LINKING MONOMERS, SAID CROSS-LINKING COMPOUND BEING PRESENT BETWEEN ABOUT 20-80 MOLE% OF THE TOTAL POLYMERIZABLE MONOMERS OF SAID MIXTURE, SAID MIXTURE FURTHER CONTAINING DISSOLVED THEREIN BETWEEN ABOUT 15 TO 75% BY VOLUME OF AN INERT, NON-POLYMERIZABLE, ORGANIC SOLVENT PAIR, SAID SOLVENT PAIR COMPRISING AT LEAST ONE GOOD SOLVENT AND AT LEAST ONE POOR SOLVENT AND POLYMERIZING SAID MONOMERIC MIXTURE UNDER CONDITIONS TO SUBSTANTIALLY PREVENT THE ESCAPE OF SAID POOR SOLVENT FROM THE MONOMER MIXTURE DURING THE FORMATION OF SAID POLYMERIZED BOARD STRUCTURE, SAID POOR SOLVENT BEING PRESENT IN AN AMOUNT OF BETWEEN ABOUT 15 TO 55% BY VOLUME BASED ON THE TOTAL VOLUME OF SAID SOLVENT PAIR.
Claim 2
Independent Claim
198 words
A METHOD OF PREPARING A SUBSTANTIALLY INSOLUBLE CROSSLINKED, POLYMERIC NON-LAMINATED, ONE PIECE BOARD SUITABLE FOR THE MANUFACTURE OF ION-SELECTIVE MEMBRANES, THE BOARDS HAVING AT LEAST TWO DIMENSIONS IN EXCESS OF ONE CENTIMETER WITH BOTH MAJOR SURFACES HAVING A MACROPOROUS STRUCTURE OF PORE DIAMETER SIZES BETWEEN ABOUT 500-1500 ANGSTROMS WITH THE INTERIOR PORTION OF SAID BOARDS SUBSTANTIALLY COMPRISIG A MICROPOROUS STRUCTURE HAVING PORE DIAMETER SIZES IN THE RANGE OF ABOUT 10-30 ANGSTROMS, THE METHOD COMPRISING PREPARING A MONOMERIC MIXTURE OF AT LEAST ONE MONOVINYL AROMATIC MONOMER AND AT LEAST ONE POLYVINYL AROMATIC CROSS-LINKING MONOMERS, SAID CROSS-LINKING COMPOUND BEING PRESENT BETWEEN ABOUT 20-80 MOLE% OF THE TOTAL POLYMERIZABLE MONOMERS OF SAID MIXTURE, SAID MIXTURE FURTHER CONTAINING DISSOLVED THEREIN BETWEEN ABOUT 15 TO 75% BY VOLUME OF AN INERT, NON-POLYMERIZABLE, ORGANIC SOLVENT PAIR, SAID SOLVENT PAIR COMPRISING AT LEAST ONE GOOD SOLVENT AND AT LEAST ONE POOR SOLVENT AND POLYMERIZING SAID MONOMERIC MIXTURE UNDER CONDITIONS TO SUBSTANTIALLY PREVENT THE ESCAPE OF SAID POOR SOLVENT FROM THE MONOMER MIXTURE DURING THE FORMATION OF SAID POLYMERIZED BOARD STRUCTURE, SAID POOR SOLVENT BEING PRESENT IN AN AMOUNT OF BETWEEN ABOUT 15 TO 55% BY VOLUME BASED ON THE TOTAL VOLUME OF SAID SOLVENT PAIR.
Claim 3
Dependent Claim
36 words
The method of claim 1 wherein the said poor solvent is selected from the group consisting of the lower alcohols, the isomers of the lower alcohols, polypropylene glycol, polyethylene glycol, isooctane and mixture of the same.
Claim 4
Dependent Claim
82 words
The method of claim 1 wherein said monovinyl aromatic monomer is selected from the group consisting of styrene, ethyl styrene, methyl styrene and mixtures thereof, said polyvinyl aromatic monomer selected from the group consisting of divinyl benzene, ethylene glycol dimethacrylate, divinyl toluene, trivinylbenzene and mixtures thereof, the said volume of the non-polymerizable solvent pair being between 20-50% and the said cross-linking monomer being polymerized in an amount equal to about 25 to 50% on a molar basis of the total polymerizable monomers.
Claim 5
Dependent Claim
46 words
The method of claim 1 wherein, the monovinyl monomer is ethyl styrene, the cross-linking monomer is divinyl benzene and wherein the resulting cross-linked polymerized board structure is treated by chloromethylation and amination whereby there is bonded to the aromatic nuclei of said monomers, quaternary ammonium groups.
Claim 6
Dependent Claim
97 words
A substantially insoluble, cross-linked, polyvinyl, polymeric non-laminated, one piece resin sheet suitable for the manufacture of ion-selective membranes, the sheet having at least two dimensions in excess of one centimeter, said sheet comprising a copolymer of at least one monovinyl aromatic monomer and at least one polyvinyl aromatic cross-linking monomer of which both major surfaces of said polymeric sheet is of a macroporous structure having pore diameter sizes between about 500-1500 angstroms with the remaining interior portion of said sheet substantially comprising the microporous structure having a pore diameter size in the range of about 10-30 angstroms.
Claim 7
Dependent Claim
97 words
A substantially insoluble, cross-linked, polyvinyl, polymeric non-laminated, one piece resin sheet suitable for the manufacture of ion-selective membranes, the sheet having at least two dimensions in excess of one centimeter, said sheet comprising a copolymer of at least one monovinyl aromatic monomer and at least one polyvinyl aromatic cross-linking monomer of which both major surfaces of said polymeric sheet is of a macroporous structure having pore diameter sizes between about 500-1500 angstroms with the remaining interior portion of said sheet substantially comprising the microporous structure having a pore diameter size in the range of about 10-30 angstroms.
Claim 8
Dependent Claim
21 words
The polymeric sheet of claim 5 wherein each macroporous surface or layer has a thickness between about 0.1 to 10 mils.
Claim 9
Dependent Claim
28 words
The polymeric sheet of claim 5 wherein there is bonded to the said aromatic nuclei of the said monomers, quarternary ammonium groups to form an anion permselective membrane.
Claim 10
Dependent Claim
22 words
The anion membrane of claim 7 characterized by a resistivity between about 20-40 ohm-cm2. and an anion transport number between about 0.80-0.94.
Claim 11
Dependent Claim
40 words
The polymeric resin sheet of claim 5 characterized by carrying the ion-exchange reactive group selected from the groups consisting of primary, secondary oR tertiary amine, quaternary ammonium, phosphonium, tertiary sulphonium, sulfonic, phosphonic, carboxy, phosphinic, thiophosphonic, arsonic groups and mixture thereof.
Claim 12
Dependent Claim
28 words
The polymeric sheet of claim 5 wherein there is bonded to the said aromatic nuclei of the said monomers, sulfonic acid groups to form a cation permselective membrane.
Claim 13
Dependent Claim
112 words
An anion permselective non-laminated, one piece membrane comprising a substantially, insoluble, cross-linked polyvinyl aromatic polymer having both major surfaces of a macroporous structure having pore diameter sizes between about 500-1500 angstroms and the remaining inner portions of the membrane of a microporous structure having pore diameter sizes between about 10-30 angstroms, said membrane possessing a resistivity of between about 20-40 ohm-cm2 and a transport number between about 0.80-0.94, said macroporous and microporous structure caused by the polymer having been prepared in the presence of a solvent pair comprising a good and a poor solvent wherein the poor solvent comprised between about 15-55% by volume of the total volume of the solvent pair.
Claim 14
Dependent Claim
112 words
An anion permselective non-laminated, one piece membrane comprising a substantially, insoluble, cross-linked polyvinyl aromatic polymer having both major surfaces of a macroporous structure having pore diameter sizes between about 500-1500 angstroms and the remaining inner portions of the membrane of a microporous structure having pore diameter sizes between about 10-30 angstroms, said membrane possessing a resistivity of between about 20-40 ohm-cm2 and a transport number between about 0.80-0.94, said macroporous and microporous structure caused by the polymer having been prepared in the presence of a solvent pair comprising a good and a poor solvent wherein the poor solvent comprised between about 15-55% by volume of the total volume of the solvent pair.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |