Patent US2494049A successfully refreshed from Google Patents.
US2494049A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of producing fumaric acid
Assignee: Chemical Concentrates Corp
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Filing: 1948-07-30
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Granted: 1950-01-10
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Expires: 1968-07-30
Abstract
No abstract record available.
Inventors
- 👤 Levin David
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:18
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/347; C07C51/353
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
94 words
THE METHOD OF PRODUCING FUMARIC ACID WHICH COMPRISES REACTING, IN AN AQUEOUS SOLUTION, 0.1 TO 10 MOLS PER LITER OF WATER PRESENT OF MALEIC ACID WITH 0.1 TO 15 MOLS PER LITER OF WATER PRESENT OF FREE HYDROHALOGEN ACID SELECTED FROM THE CLASS CONSISTING OF HYDROCHLORIC ACID AND HYDROBROMIC ACID IN THE PRESENCE OF 0.1 MOL PER LITER OF WATER PRESENT TO THE SOLUBILITY LIMIT OF A HALIDE SELECTED FROM THE CLASS CONSISTING OF ALKALI METAL CHLORIDES, ALKALI METAL BROMIDES, AMMONIUM CHLORIDE AND AMMONIUM BROMIDE AND SEPARATING THE RESULTING FUMARIC ACID FROM THE MIXTURE.
Claim 2
Independent Claim
94 words
THE METHOD OF PRODUCING FUMARIC ACID WHICH COMPRISES REACTING, IN AN AQUEOUS SOLUTION, 0.1 TO 10 MOLS PER LITER OF WATER PRESENT OF MALEIC ACID WITH 0.1 TO 15 MOLS PER LITER OF WATER PRESENT OF FREE HYDROHALOGEN ACID SELECTED FROM THE CLASS CONSISTING OF HYDROCHLORIC ACID AND HYDROBROMIC ACID IN THE PRESENCE OF 0.1 MOL PER LITER OF WATER PRESENT TO THE SOLUBILITY LIMIT OF A HALIDE SELECTED FROM THE CLASS CONSISTING OF ALKALI METAL CHLORIDES, ALKALI METAL BROMIDES, AMMONIUM CHLORIDE AND AMMONIUM BROMIDE AND SEPARATING THE RESULTING FUMARIC ACID FROM THE MIXTURE.
Claim 3
Independent Claim
138 words
THE METHOD OF PRODUCING FUMARIC ACID FROM A LIQUOR CONTANING MALEIC ACID WHICH COMPRISES PARTIALLY NEUTRALIZING THE WASTE LIQUOR BY THE ADDITION OF A MEMBER SELECTED FROM THE CLASS CONSISTING OF SODIUM CARBONATE, SODIUM BICARBONATE AND SODIUM HYDROXIDE UNTIL THE PH OF SAID LIQUOR IS WITHIN THE RANGE OF 3.5 TO 3.7, COOLING THE MIXTURE TO BELOW 25*C., SEPARATING THE PRECIPITATED SODIUM ACID MALEATE FROM THE MIXTURE, REACTING IN AN AQUEOUS MEDIUM ABOUT 4 MOLS PER LITER OF WATER PRESENT OF THE SEPARATED SODIUM ACID MALEATE WITH HYDROCHLORIC ACID IN THE PRESENCE OF ABOUT 4 MOLS OF SODIUM CHLORIDE PER LITER OF WATER PRESENT AND SEPARATING THE RESULTING FUMARIC ACID FROM THE MIXTURE, THE AMOUNT OF HYDROCHLORIC ACID BEING ABOUT 2 MOLS PER LITER OF WATER PRESENT ABOVE THAT THEORETICALLY REQUIRED TO CONVERT THE MALEATE TO MALEIC ACID.
Claim 4
Independent Claim
138 words
THE METHOD OF PRODUCING FUMARIC ACID FROM A LIQUOR CONTANING MALEIC ACID WHICH COMPRISES PARTIALLY NEUTRALIZING THE WASTE LIQUOR BY THE ADDITION OF A MEMBER SELECTED FROM THE CLASS CONSISTING OF SODIUM CARBONATE, SODIUM BICARBONATE AND SODIUM HYDROXIDE UNTIL THE PH OF SAID LIQUOR IS WITHIN THE RANGE OF 3.5 TO 3.7, COOLING THE MIXTURE TO BELOW 25*C., SEPARATING THE PRECIPITATED SODIUM ACID MALEATE FROM THE MIXTURE, REACTING IN AN AQUEOUS MEDIUM ABOUT 4 MOLS PER LITER OF WATER PRESENT OF THE SEPARATED SODIUM ACID MALEATE WITH HYDROCHLORIC ACID IN THE PRESENCE OF ABOUT 4 MOLS OF SODIUM CHLORIDE PER LITER OF WATER PRESENT AND SEPARATING THE RESULTING FUMARIC ACID FROM THE MIXTURE, THE AMOUNT OF HYDROCHLORIC ACID BEING ABOUT 2 MOLS PER LITER OF WATER PRESENT ABOVE THAT THEORETICALLY REQUIRED TO CONVERT THE MALEATE TO MALEIC ACID.
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) | 1953-01-09 | 1953-07-11 | 1954-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-01-09 | 1957-07-11 | 1958-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-01-09 | 1961-07-11 | 1962-01-10 | $7700.00 | Window Closed / Lapsed |