US4714530A
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Method for producing high purity quaternary ammonium hydroxides
Assignee: Sachem Inc
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Filing: 1986-07-11
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Granted: 1987-12-22
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Expires: 2006-07-11
Abstract
Abstract A process is described for improving the purity of quaternary ammonium hydroxides. In one embodiment, the process of the present invention comprises the steps of (a) charging an aqueous solution containing the quaternary ammonium hydroxide to the anolyte compartment of an electrolysis cell which comprises an anolyte compartment and a catholyte compartment containing water separated from each other by a cation-exchange membrane, (b) passing a direct current through the electrolysis cell to produce a high purity quaternary ammonium hydroxide in the catholyte compartment, and (c) recovering the high purity quaternary ammonium hydroxide from the catholyte compartment. In a preferred embodiment, the aqueous solution containing the quaternary ammonium hydroxide charged to the anolyte compartment is heated to an elevated temperature for a given period of time prior to subjecting the quaternary ammonium hydroxide to the electrolytic process of the present invention. The process of the present invention results in the formation of quaternary ammonium hydroxide solutions containing significantly reduced amounts of halogen (both ionic and latent), carbonates and/or metals, and the solutions also are characterized by improved color.
Inventors
- 👤 Cecil H. Hale
- 👤 Alan R. Tanner
- 👤 Bryan M. Hale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:47
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/42; B01D61/44; C; C07; C07C; C07C209/00; C07C209/82; C07C209/84; C25; C25B; C25B3/00
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
96 words
A process of improving the purity of quaternary ammonium hydroxides obtained by the electrolysis of the corresponding quaternary ammonium salt which comprises the steps of (a) charging an aqueous solution containing the quaternary ammonium hydroxide to the anolyte compartment of an electrolysis cell which comprises an anolyte compartment and a catholyte compartment containing water separated from each other by a cation-exchange membrane, (b) passing a direct current through the electrolysis cell to produce a high purity quaternary ammonium hydroxide in the catholyte compartment, and (c) recovering the high purity quaternary ammonium hydroxide from the catholyte compartment.
Claim 2
Dependent Claim
96 words
A process of improving the purity of quaternary ammonium hydroxides obtained by the electrolysis of the corresponding quaternary ammonium salt which comprises the steps of (a) charging an aqueous solution containing the quaternary ammonium hydroxide to the anolyte compartment of an electrolysis cell which comprises an anolyte compartment and a catholyte compartment containing water separated from each other by a cation-exchange membrane, (b) passing a direct current through the electrolysis cell to produce a high purity quaternary ammonium hydroxide in the catholyte compartment, and (c) recovering the high purity quaternary ammonium hydroxide from the catholyte compartment.
Claim 3
Dependent Claim
58 words
The method of claim 1 wherein the quaternary ammonium hydroxide is characterized by the formula ##STR2## wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl or hydroxyalkyl groups containing from one to about 10 carbon atoms, alkoxyalkyl groups containing from two to about 10 carbon atoms, aryl groups, or hydroxyaryl groups.
Claim 4
Dependent Claim
30 words
The method of claim 2 wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl or hydroxyalkyl groups containing one to three carbon atoms.
Claim 5
Dependent Claim
22 words
The method of claim 2 wherein R 1 , R 2 , R 3 and R 4 are methyl or ethyl groups.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein the quaternary ammonium salt is a quaternary ammonium halide.
Claim 7
Dependent Claim
15 words
The method of claim 5 wherein the quaternary ammonium halide is a quaternary ammonium chloride.
Claim 8
Dependent Claim
21 words
The method of claim 1 wherein the cation-exchange membrane comprises a perfluorosulfonic acid or a perfluorosulfonic acid/perfluorocarboxylic acid perfluorohydrocarbon polymer membrane.
Claim 9
Dependent Claim
30 words
The process of claim 1 wherein the concentration of the quaternary ammonium hydroxide in the aqueous solution charged in step (a) is from about 3 to about 55% by weight.
Claim 10
Dependent Claim
17 words
The process of claim 8 wherein the concentration is from about 5 to about 30% by weight.
Claim 11
Dependent Claim
57 words
The method of claim 1 wherein the aqueous solution containing the quaternary ammonium hydroxide charged to the anolyte compartment is heated at an elevated temperature of from about 50° C. to about 200° C. for a period of from about 0.1 hour to about 4 days prior to being charged to the anolyte compartment in step (a).
Claim 12
Dependent Claim
172 words
A process for improving the purity of quaternary ammonium hydroxides prepared by electrolyzing a quaternary ammonium halide salt in an electrolysis cell containing a cation-exchange membrane which comprises the steps of (a) charging an aqueous solution containing said quaternary ammonium hydroxide into the anolyte compartment of an electrolysis cell comprising an anolyte compartment and a water-containing catholyte compartment separated by a cation-exchange membrane, said aqueous solution containing a concentration of halide ions, and said quaternary ammonium hydroxide being characterized by the formula ##STR3## wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl or hydroxyalkyl groups containing from one to about 10 carbon atoms, (b) passing a direct current into the electrolysis cell for a period of time effective to form a quaternary ammonium hydroxide in the catholyte compartment, and (c) recovering the quaternary ammonium hydroxide from the catholyte compartment, said quaternary ammonium hydroxide containing less halogen than the amount of halogen present in the quaternary ammonium hydroxide charged to the anolyte compartment in step (a).
Claim 13
Dependent Claim
172 words
A process for improving the purity of quaternary ammonium hydroxides prepared by electrolyzing a quaternary ammonium halide salt in an electrolysis cell containing a cation-exchange membrane which comprises the steps of (a) charging an aqueous solution containing said quaternary ammonium hydroxide into the anolyte compartment of an electrolysis cell comprising an anolyte compartment and a water-containing catholyte compartment separated by a cation-exchange membrane, said aqueous solution containing a concentration of halide ions, and said quaternary ammonium hydroxide being characterized by the formula ##STR3## wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl or hydroxyalkyl groups containing from one to about 10 carbon atoms, (b) passing a direct current into the electrolysis cell for a period of time effective to form a quaternary ammonium hydroxide in the catholyte compartment, and (c) recovering the quaternary ammonium hydroxide from the catholyte compartment, said quaternary ammonium hydroxide containing less halogen than the amount of halogen present in the quaternary ammonium hydroxide charged to the anolyte compartment in step (a).
Claim 14
Dependent Claim
29 words
The process of claim 11 wherein the concentration of quaternary ammonium hydroxide in the aqueous solution recovered in step (c) is between about 5 to about 40% by weight.
Claim 15
Dependent Claim
24 words
The process of claim 11 wherein R 1 , R 2 , R 3 and R 4 each contain one or two carbon atoms.
Claim 16
Dependent Claim
20 words
The process of claim 11 wherein R 1 , R 2 , R 3 and R 4 are methyl groups.
Claim 17
Dependent Claim
48 words
The process of claim 11 wherein the quaternary ammonium hydroxide solution charged in step (a) is heated at a temperature of from about 50° to about 200° C. for a period of at least about 0.1 hour prior to being charged to the anolyte compartment in step (a).
Claim 18
Dependent Claim
33 words
The process of claim 15 wherein the aqueous solution is heated at a temperature of from about 80° to about 175° C. for a period of about 0.1 hour to about 4 days.
Claim 19
Dependent Claim
134 words
A process for reducing the halide content of quaternary ammonium hydroxides prepared by the electrolysis of quaternary ammonium halides which comprises the steps of (a) heating said quaternary ammonium hydroxide at an elevated temperature of from about 50° to about 200° C. for a period of at least about 0.1 hour, (b) charging said aqueous quaternary ammonium hydroxide solution obtained in step (a) into the anolyte compartment of an electrolysis cell comprising an anolyte compartment and a water-containing catholyte compartment separated by a cation-exchange membrane, (c) passing a direct current through the electrolysis cell for a period of time sufficient to form the quaternary ammonium hydroxide in the catholyte compartment, and (d) recovering the quaternary ammonium hydroxide solution from the catholyte compartment, said solution containing less halide than the solution heated in step (a).
Claim 20
Dependent Claim
134 words
A process for reducing the halide content of quaternary ammonium hydroxides prepared by the electrolysis of quaternary ammonium halides which comprises the steps of (a) heating said quaternary ammonium hydroxide at an elevated temperature of from about 50° to about 200° C. for a period of at least about 0.1 hour, (b) charging said aqueous quaternary ammonium hydroxide solution obtained in step (a) into the anolyte compartment of an electrolysis cell comprising an anolyte compartment and a water-containing catholyte compartment separated by a cation-exchange membrane, (c) passing a direct current through the electrolysis cell for a period of time sufficient to form the quaternary ammonium hydroxide in the catholyte compartment, and (d) recovering the quaternary ammonium hydroxide solution from the catholyte compartment, said solution containing less halide than the solution heated in step (a).
Claim 21
Dependent Claim
43 words
The process of claim 17 wherein the quaternary ammonium hydroxide is represented by the formula ##STR4## wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl or hydroxyalkyl groups containing from one to about 10 carbon atoms.
Claim 22
Dependent Claim
24 words
The process of claim 18 wherein R 1 , R 2 , R 3 and R 4 contain from one to three carbon atoms.
Claim 23
Dependent Claim
20 words
The process of claim 18 wherein R 1 , R 2 , R 3 and R 4 are methyl groups.
Claim 24
Dependent Claim
21 words
The process of claim 17 wherein the cation-exchange membrane is a perfluorosulfonic acid or a perfluorosulfonic acid/perfluorocarboxylic acid perfluorocarbon polymer membrane.
Claim 25
Dependent Claim
22 words
The process of claim 17 wherein the quaternary hydroxide heated in step (a) is obtained by the electrolysis of the corresponding chloride.
Claim 26
Dependent Claim
12 words
The aqueous quaternary ammonium hydroxide obtained by the process of claim 1.
Claim 27
Dependent Claim
12 words
The aqueous quaternary ammonium hydroxide obtained by the process of claim 11.
Claim 28
Dependent Claim
12 words
The aqueous quaternary ammonium hydroxide obtained by the process of claim 17.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-12-21 | 1991-06-22 | 1991-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-21 | 1995-06-22 | 1995-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-21 | 1999-06-22 | 1999-12-22 | $7700.00 | Window Closed / Lapsed |