Patent US5145569A successfully refreshed from Google Patents.
US5145569A
Expired / Lapsed
US
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Process for desalting solvent-containing electrolyte solutions by electrodialysis
Assignee: Hoechst AG
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Filing: 1990-01-31
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Granted: 1992-09-08
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Expires: 2010-01-31
Abstract
Abstract A process for desalting mixtures of water and water-soluble highly active organic solvents, which contain metal salts, which comprises subjecting the mixtures to electrodialysis employing commercially available ion exchanger membranes. The electrodes are preferably washed with an electrolyte solution which is free of sulfate ions.
Inventors
- 👤 Michael Schneider
- 👤 Georg E. Miess
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:18
CPC Classifications
D; D01; D01F; D01F13/00; D01F13/04; B; B01; B01D; B01D61/00; B01D61/42; B01D61/44; Y; Y02; Y02A; Y02A20/00; Y02A20/124; Y02P; Y02P70/00; Y02P70/50; Y02P70/62
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
52 words
A process for desalting mixtures of water and water-soluble highly active organic solvents, which contain metal salts, which comprises subjecting mixtures of water and 20% to 80% by weight water-soluble highly active organic solvents selected from the group consisting of tetramethylurea, dimethylacetamide and N-methylpyrrolidone to electrodialysis employing commercially available ion exchanger membranes.
Claim 2
Dependent Claim
52 words
A process for desalting mixtures of water and water-soluble highly active organic solvents, which contain metal salts, which comprises subjecting mixtures of water and 20% to 80% by weight water-soluble highly active organic solvents selected from the group consisting of tetramethylurea, dimethylacetamide and N-methylpyrrolidone to electrodialysis employing commercially available ion exchanger membranes.
Claim 3
Dependent Claim
22 words
The process as claimed in claim 1, wherein the electrodes are washed with an electrolyte solution which is free of sulfate ions.
Claim 4
Dependent Claim
20 words
The process as claimed in claim 1, wherein ion exchanger membranes based on copolymers of styrene and divinylbenzene are employed.
Claim 5
Dependent Claim
27 words
The process as claimed in claim 1, wherein ion exchanger membranes with a capacity of 0.8 to 3, preferably 1.2 to 2.2, milliequivalent per g are employed.
Claim 6
Dependent Claim
18 words
The process as claimed in claim 1, wherein the process is carried out at 10 to 40° C.
Claim 7
Dependent Claim
19 words
The process as claimed in claim 1, wherein a current density of 1 to 200 A/m 2 is used.
Claim 8
Dependent Claim
28 words
The process as claimed in claim 1, including using an electrode washing solution comprising an aqueous solution of an alkali metal salt of a lower organic carboxylic acid.
Claim 9
Dependent Claim
19 words
The process as claimed in claim 1, including using an electrode washing solution comprising an aqueous sodium acetate solution.
Claim 10
Dependent Claim
32 words
The use of the process of claim 1 for desalting mixtures of water and organic solvents which contain up to 80% by weight solvent and up to 10% by weight metal salts.
Claim 11
Dependent Claim
13 words
The use of the process of claim 1 for desalting coagulating spin baths.
Claim 12
Dependent Claim
71 words
A process for desalting mixtures of water and water-soluble highly active organic solvents, which contain metal salts, which comprises subjecting mixtures of water and 20% to 80% by weight water-soluble highly active organic solvents used in the manufacture of aliphatic or aromatic polyamide fibers and polyimide fibers to electrodialysis employing commercially available ion exchanger membranes, and wherein the electrodes are washed with an electrolyte solution which is free of sulfate ions.
Claim 13
Dependent Claim
71 words
A process for desalting mixtures of water and water-soluble highly active organic solvents, which contain metal salts, which comprises subjecting mixtures of water and 20% to 80% by weight water-soluble highly active organic solvents used in the manufacture of aliphatic or aromatic polyamide fibers and polyimide fibers to electrodialysis employing commercially available ion exchanger membranes, and wherein the electrodes are washed with an electrolyte solution which is free of sulfate ions.
Claim 14
Dependent Claim
76 words
A process for desalting mixtures of water and water-soluble highly active organic solvents, which contain metal salts, which comprises subjecting mixtures of water and 20% to 80% by weight water-soluble highly active organic solvents used in the manufacture of aliphatic or aromatic polyamide fibers and polyimide fibers to electrodialysis employing commercially available ion exchanger membranes, and using an electrode washing solution comprising an aqueous solution of an alkali metal salt of a lower organic carboxylic acid.
Claim 15
Dependent Claim
76 words
A process for desalting mixtures of water and water-soluble highly active organic solvents, which contain metal salts, which comprises subjecting mixtures of water and 20% to 80% by weight water-soluble highly active organic solvents used in the manufacture of aliphatic or aromatic polyamide fibers and polyimide fibers to electrodialysis employing commercially available ion exchanger membranes, and using an electrode washing solution comprising an aqueous solution of an alkali metal salt of a lower organic carboxylic acid.
Claim 16
Dependent Claim
67 words
A process for desalting mixtures of water and water-soluble highly active organic solvents, which contain metal salts, which comprises subjecting mixtures of water and 20% to 80% by weight water-soluble highly active organic solvents used in the manufacture of aliphatic or aromatic polyamide fibers and polyimide fibers to electrodialysis employing commercially available ion exchanger membranes, and using an electrode washing solution comprising an aqueous sodium acetate solution.
Claim 17
Dependent Claim
67 words
A process for desalting mixtures of water and water-soluble highly active organic solvents, which contain metal salts, which comprises subjecting mixtures of water and 20% to 80% by weight water-soluble highly active organic solvents used in the manufacture of aliphatic or aromatic polyamide fibers and polyimide fibers to electrodialysis employing commercially available ion exchanger membranes, and using an electrode washing solution comprising an aqueous sodium acetate solution.
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) | 1995-09-08 | 1996-03-09 | 1996-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-08 | 2000-03-09 | 2000-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-08 | 2004-03-09 | 2004-09-08 | $7700.00 | Window Closed / Lapsed |