US2697723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of isophthalic and terephthalic acid mixtures
Assignee: California Research LLC
•
Filing: 1952-06-26
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Granted: 1954-12-21
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Expires: 1972-06-26
Abstract
No abstract record available.
Inventors
- 👤 Earl F Carlston
- 👤 Funston G Lum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:55
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
56 words
A PROCESS FOR SEPARATING MIXTURES OF AN ALKALI METAL SALT OF ISOPHTHALIC ACID AND THE SAME ALKALI METAL SALT OF TEREPHTHALIC ACID WHICH COMPRISES FORMING AN INTIMATE MIXTURE OF THE SALTS WITH A QUANTITY OF WATER INSUFFICIENT TO DISSOLVE ALL OF THE SALTS AND SEPARATING A SOLID PHASE AND A LIQUID PHASE FROM THE INTIMATE MIXTURE.
Claim 2
Dependent Claim
56 words
A PROCESS FOR SEPARATING MIXTURES OF AN ALKALI METAL SALT OF ISOPHTHALIC ACID AND THE SAME ALKALI METAL SALT OF TEREPHTHALIC ACID WHICH COMPRISES FORMING AN INTIMATE MIXTURE OF THE SALTS WITH A QUANTITY OF WATER INSUFFICIENT TO DISSOLVE ALL OF THE SALTS AND SEPARATING A SOLID PHASE AND A LIQUID PHASE FROM THE INTIMATE MIXTURE.
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) | 1957-12-20 | 1958-06-21 | 1958-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-12-20 | 1962-06-21 | 1962-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-12-20 | 1966-06-21 | 1966-12-21 | $7700.00 | Window Closed / Lapsed |