US2664440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of isophthalic and terephthalic acids from their mixtures
Assignee: California Research LLC
•
Filing: 1952-10-04
•
Granted: 1953-12-29
•
Expires: 1972-10-04
Abstract
No abstract record available.
Inventors
- 👤 Jr William G Toland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:05
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/487
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
72 words
A PROCESS FOR SEPARATING MIXTURES OF ISOPHTHALIC ACID AND TEREPHTHALIC ACID WHICH COMPRISES NEUTRALIZING THE ACIDS WITH A TERTIARY AMINE, FORMING A CONCENTRATED AQUEOUS SOLUTION OF THE SALTS THUS OBTAINED, CRYSTALLIZING A FRACTION OF THE DISSOVLED SALTS FROM THE SOLUTION, SEPARATING THE SALT FRACTION CRYSTALLIZED FROM THE SOLUTION, HEATING SAID FRACTION TO DECOMPOSE THE SALTS TO THEIR CORRESPONDING ACIDS AND TERTIARY AMINE AND RECOVERING THE TERTIARY AMINE AND ACIDS AS DECOMPOSITION PRODUCTS.
Claim 2
Dependent Claim
72 words
A PROCESS FOR SEPARATING MIXTURES OF ISOPHTHALIC ACID AND TEREPHTHALIC ACID WHICH COMPRISES NEUTRALIZING THE ACIDS WITH A TERTIARY AMINE, FORMING A CONCENTRATED AQUEOUS SOLUTION OF THE SALTS THUS OBTAINED, CRYSTALLIZING A FRACTION OF THE DISSOVLED SALTS FROM THE SOLUTION, SEPARATING THE SALT FRACTION CRYSTALLIZED FROM THE SOLUTION, HEATING SAID FRACTION TO DECOMPOSE THE SALTS TO THEIR CORRESPONDING ACIDS AND TERTIARY AMINE AND RECOVERING THE TERTIARY AMINE AND ACIDS AS DECOMPOSITION PRODUCTS.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-12-28 | 1957-06-29 | 1957-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-12-28 | 1961-06-29 | 1961-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-12-28 | 1965-06-29 | 1965-12-29 | $7700.00 | Window Closed / Lapsed |