US3867439A
Expired / Lapsed
US
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Preparation of potassium benzoate
Assignee: Dow Chemical Co
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Filing: 1972-04-17
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Granted: 1975-02-18
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Expires: 1992-04-17
Abstract
Abstract Substantially pure potassium benzoate is obtained in high yield by reacting an aromatic hydrocarbon solution of benzoic acid such as that obtained from a toluene oxidation process with potassium hydroxide preferably in concentrated aqueous solution, thereby precipitating solid potassium benzoate.
Inventors
- 👤 David J Hills
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:36
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/41; C07C51/412
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
140 words
IN THE PROCESS WHEREIN LIQUID TOLUENE IS OXIDIZED TO BENZOIC ACID BY MOLECULAR OXYGEN IN THE PRESENCE OF A HEAVY METAL COMPOUND CATALYST AT ABOUT 100*-200*C., THEREBY PRODUCING A LIQUID PROCESS EFFLUENT CONSISTING ESSENTIALLY OF A TOLUENE SOLUTION OF BENZOIC ACID AND METAL COMPOUND, THE IMPROVEMENT WHEREBY BENZOIC ACID IS SEPARATED FROM SAID EFFLUET AS THE SUBSTANTIALLY PURE POTASSIUM SALT BY TREATING THE LIQUID EFFLUENT TO REMOVE AT LEAST A SUBSTANTIAL PART OF SAID HEAVY METAL COMPOUND AND TO ADJUST THE BENZOIC ACID CONCENTRATION TO ABOUT 5-30 PERCENT BY WEIGHT, ADDING POTASSIUM HYDROXIDE CONTAINING UP TO 60 PERCENT BY WEIGHT, OF WATER TO THE ADJUSTED EFFLUENT AT A TEMPERATURE BETWEEN THE CRYSTALLIZATION POINT OF THE BENZOIC ACID SOLUTION AND ABOUT 150*C., THEREBY FORMING A SLURRY OF SOLID POTASSIUM BENZOATE FROM SAID TOLUENE AND SEPARATING SAID POTASSIUM BENZOATE FROM SAID SLURRY.
Claim 2
Dependent Claim
140 words
IN THE PROCESS WHEREIN LIQUID TOLUENE IS OXIDIZED TO BENZOIC ACID BY MOLECULAR OXYGEN IN THE PRESENCE OF A HEAVY METAL COMPOUND CATALYST AT ABOUT 100*-200*C., THEREBY PRODUCING A LIQUID PROCESS EFFLUENT CONSISTING ESSENTIALLY OF A TOLUENE SOLUTION OF BENZOIC ACID AND METAL COMPOUND, THE IMPROVEMENT WHEREBY BENZOIC ACID IS SEPARATED FROM SAID EFFLUET AS THE SUBSTANTIALLY PURE POTASSIUM SALT BY TREATING THE LIQUID EFFLUENT TO REMOVE AT LEAST A SUBSTANTIAL PART OF SAID HEAVY METAL COMPOUND AND TO ADJUST THE BENZOIC ACID CONCENTRATION TO ABOUT 5-30 PERCENT BY WEIGHT, ADDING POTASSIUM HYDROXIDE CONTAINING UP TO 60 PERCENT BY WEIGHT, OF WATER TO THE ADJUSTED EFFLUENT AT A TEMPERATURE BETWEEN THE CRYSTALLIZATION POINT OF THE BENZOIC ACID SOLUTION AND ABOUT 150*C., THEREBY FORMING A SLURRY OF SOLID POTASSIUM BENZOATE FROM SAID TOLUENE AND SEPARATING SAID POTASSIUM BENZOATE FROM SAID SLURRY.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein about 0.5-1 mole of potassium hydroxide is added per mole of benzoic acid.
Claim 4
Dependent Claim
19 words
The process of claim 1 where about a mole of potassium hydroxide is added per mole of benzoic acid.
Claim 5
Dependent Claim
15 words
The process of claim 1 wherein the potassium hydroxide is added as a powdered solid.
Claim 6
Dependent Claim
16 words
The process of claim 1 wherein the potassium hydroxide is employed as a liquid aqueous solution.
Claim 7
Dependent Claim
17 words
The process of claim 5 wherein the aqueous solutions contains 50-66 per cent by weight of KOH.
Claim 8
Dependent Claim
19 words
The process of claim 1 wherein the benzoic acid solution contains 10-20 per cent by weight of benzoic acid.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein the metal compound is removed from the liquid effluent by an aqueous extraction.
Claim 10
Dependent Claim
45 words
The process of claim 8 wherein the aqueous extraction is carried out using a minor proportion based on the liquid effluent of dilute aqueous mineral acid as the aqueous extractant wherein the mineral acid is hydrochloric acid, nitric acid, sulfuric acid, or a mixture thereof.
Claim 11
Dependent Claim
28 words
The process of claim 1 wherein the potassium hydroxide is added to the adjusted benzoic acid solution at between ambient temperature and the boiling point of the solution.
References Cited (Backward Citations)
US3259651A
Cited
US3309289A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |