US2716133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification and separation of dicarboxylic acids
Assignee: CP Hall Co
•
Filing: 1950-06-21
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Granted: 1955-08-23
•
Expires: 1970-06-21
Abstract
No abstract record available.
Inventors
- 👤 Leo S Pooler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:24
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/43
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
102 words
THE PROCESS OF RECOVERING DICARBOXYLIC ACID FROM A SOLUTION OF LONGER AND SHORTER CHAIN DICARBOXYLIC ACIDS IN A DICHLORO BENZENE, WHICH COMPRISES COOLING THE SOLUTION FROM A RELATIVELY HIGH TEMPERATURE AT WHICH AT LEAST A PART OF THE ACID OF SHORTEST CHAIN LENGTH IS CRYSTALLIZED FROM THE SOLUTION WHILE RETAINING ACID OF LONGER CHAIN LENGTH IN SOLUTION, DISSOLVING IN WATER AT A RELATIVELY HIGH TEMPERATURE ACID THUS CRYSTALLIZED FROM THE SOLUTION AND ADDING A MINOR PER CENT OF NITRIC ACID THERETO, AND THEN COOLING THIS AQUEOUS SOLUTION TO A RELATIVELY LOW TEMPERATURE AND THERBY CRYSTALLIZING DICARBOXYLIC ACID OF SHORTER CHAIN LENGTH THEREFROM.
Claim 2
Dependent Claim
102 words
THE PROCESS OF RECOVERING DICARBOXYLIC ACID FROM A SOLUTION OF LONGER AND SHORTER CHAIN DICARBOXYLIC ACIDS IN A DICHLORO BENZENE, WHICH COMPRISES COOLING THE SOLUTION FROM A RELATIVELY HIGH TEMPERATURE AT WHICH AT LEAST A PART OF THE ACID OF SHORTEST CHAIN LENGTH IS CRYSTALLIZED FROM THE SOLUTION WHILE RETAINING ACID OF LONGER CHAIN LENGTH IN SOLUTION, DISSOLVING IN WATER AT A RELATIVELY HIGH TEMPERATURE ACID THUS CRYSTALLIZED FROM THE SOLUTION AND ADDING A MINOR PER CENT OF NITRIC ACID THERETO, AND THEN COOLING THIS AQUEOUS SOLUTION TO A RELATIVELY LOW TEMPERATURE AND THERBY CRYSTALLIZING DICARBOXYLIC ACID OF SHORTER CHAIN LENGTH THEREFROM.
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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) | 1958-08-22 | 1959-02-21 | 1959-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-08-22 | 1963-02-21 | 1963-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-08-22 | 1967-02-21 | 1967-08-23 | $7700.00 | Window Closed / Lapsed |