US2732399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for separating isophthalic acid
Assignee: —
•
Filing: —
•
Granted: 1956-01-24
•
Expires: 1973-01-24
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:40
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
67 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 CONCENTRATED AQUEOUS SOLUTION OF A WATER-MISCIBLE ALCOHOL, SAID AQUEOUS SOLUTION BEING INSUFFICIENT TO DISSOLVE ALL OF THE MIXED ALKALI METAL PHTHALATES AND SEPARATING A SOLID PHASE AND A LIQUID PHASE FROM THE INTIMATE MIXTURE.
Claim 2
Dependent Claim
67 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 CONCENTRATED AQUEOUS SOLUTION OF A WATER-MISCIBLE ALCOHOL, SAID AQUEOUS SOLUTION BEING INSUFFICIENT TO DISSOLVE ALL OF THE MIXED ALKALI METAL PHTHALATES AND SEPARATING A SOLID PHASE AND A LIQUID PHASE FROM THE INTIMATE MIXTURE.
References Cited (Backward Citations)
GB623836A
Cited
US2531173A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-01-23 | 1959-07-25 | 1960-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-01-23 | 1963-07-25 | 1964-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-01-23 | 1967-07-25 | 1968-01-24 | $7700.00 | Window Closed / Lapsed |