Patent US2863880A successfully refreshed from Google Patents.
US2863880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous dehydration of aqueous solutions of crude maleic acid
Assignee: California Spray Chemical Corp
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Filing: 1957-07-23
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Granted: 1958-12-09
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Expires: 1977-07-23
Abstract
No abstract record available.
Inventors
- 👤 Gustave K Kohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:42
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/56
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
75 words
A PROCESS FOR DEHYDRATING MALEIC ACID ASSOCIATED WITH AT LEAST 50 P. P. M. OF ALKALI METAL CATION TO MALEIC ANHYDRIDE WITHOUT APPRECIABLE DECOMPOSITION OF MALEIC ANHYDRIDE, WHICH COMPRISES INCORPORATING WITH SAID MALEIC ACID A MINOR PROPORTION OF AN OXYGEN ACID OF PENTAVALENT PHOSPHORUS IN AMOUNTS OF AT LEAST ONE EQUIVALENT ACID GROUP PER ATOMIC EQUIVALENT OF ALKALI METAL CATION, AND SUBJECTING THE COMPOUNDED MALEIC ACID TO DEHYDRATING CONDITIONS AND RECOVERING THE RESULTANT MALEIC ANHYDRIDE.
Claim 2
Dependent Claim
75 words
A PROCESS FOR DEHYDRATING MALEIC ACID ASSOCIATED WITH AT LEAST 50 P. P. M. OF ALKALI METAL CATION TO MALEIC ANHYDRIDE WITHOUT APPRECIABLE DECOMPOSITION OF MALEIC ANHYDRIDE, WHICH COMPRISES INCORPORATING WITH SAID MALEIC ACID A MINOR PROPORTION OF AN OXYGEN ACID OF PENTAVALENT PHOSPHORUS IN AMOUNTS OF AT LEAST ONE EQUIVALENT ACID GROUP PER ATOMIC EQUIVALENT OF ALKALI METAL CATION, AND SUBJECTING THE COMPOUNDED MALEIC ACID TO DEHYDRATING CONDITIONS AND RECOVERING THE RESULTANT MALEIC ANHYDRIDE.
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) | 1961-12-08 | 1962-06-09 | 1962-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-08 | 1966-06-09 | 1966-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-08 | 1970-06-09 | 1970-12-09 | $7700.00 | Window Closed / Lapsed |