US2832802A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of purified maleic acid
Assignee: California Spray Chemical Corp
•
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 07:21
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.
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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 |