Patent US2832802A successfully refreshed from Google Patents.
US2832802A
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Recovery of purified maleic acid
Assignee: California Spray Chemical Corp
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Filing: 1954-09-07
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Granted: 1958-04-29
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Expires: 1974-09-07
Abstract
No abstract record available.
Inventors
- 👤 Gustave K Kohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:47
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/48
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
98 words
A METHOD OF TREATING AN AQUEOUS SOLUTION OF MALEIC ACID CONTAINING ASSOCIATED IMPURITIES AND ALKALI METAL CATIONS WHICH COMPRISES INTRODUCING SAID AQUEOUS SOLUTION OF MALEIC ACID INTO CONTACT WITH AN INERT LIQUID COMPOSED OF SATURATED ALIPHATIC HYDROCARBONS BOILING IN THE RANGE OF 180* TO 400*C., MAINTAINING SAID INERT LIQUID AT REFLUX TEMPERATURES, INTRODUCING SAID AQUEOUS SOLUTION OF MALEIC ACIOD AT A RATE NOT GREATER THAN THE RATE OF CONVERSIOON OF MALEIC ACID TO MALEIC ANHYDRIDE, WITHDRAWING AND AT LEAST PARTIALLY CONDENSING THE RESULTING VAPOR PHASE MIXTURE OF MALEIC ANHYDRIDE AND WATER AND RECOVERING A PURIFIED MALEIC ACID SOLUTION.
Claim 2
Independent Claim
98 words
A METHOD OF TREATING AN AQUEOUS SOLUTION OF MALEIC ACID CONTAINING ASSOCIATED IMPURITIES AND ALKALI METAL CATIONS WHICH COMPRISES INTRODUCING SAID AQUEOUS SOLUTION OF MALEIC ACID INTO CONTACT WITH AN INERT LIQUID COMPOSED OF SATURATED ALIPHATIC HYDROCARBONS BOILING IN THE RANGE OF 180* TO 400*C., MAINTAINING SAID INERT LIQUID AT REFLUX TEMPERATURES, INTRODUCING SAID AQUEOUS SOLUTION OF MALEIC ACIOD AT A RATE NOT GREATER THAN THE RATE OF CONVERSIOON OF MALEIC ACID TO MALEIC ANHYDRIDE, WITHDRAWING AND AT LEAST PARTIALLY CONDENSING THE RESULTING VAPOR PHASE MIXTURE OF MALEIC ANHYDRIDE AND WATER AND RECOVERING A PURIFIED MALEIC ACID SOLUTION.
References Cited (Backward Citations)
US2734854A
Cited
US1424138A
Cited
US2129166A
Cited
US2140140A
Cited
US2250091A
Cited
US2340490A
Cited
US2683110A
Cited
US2729599A
Cited
US2670355A
Cited
US2696489A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-04-28 | 1961-10-28 | 1962-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-04-28 | 1965-10-28 | 1966-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-04-28 | 1969-10-28 | 1970-04-29 | $7700.00 | Window Closed / Lapsed |