Patent US2734854A successfully refreshed from Google Patents.
US2734854A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification and recovery of maleic
Assignee: —
•
Filing: —
•
Granted: 1956-02-14
•
Expires: 1973-02-14
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:47
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/573
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
83 words
A METHOD OF RECOVERING MALEIC ANHYDRIDE FROM IMPURITIES AND ASSOCIATED COMPOUNDS WHICH COMPRISES CONTINUOUSLY INTRODUCING TO A BODY OF IMPURE MALEIC ANHYDRIDE AN ORGANIC LIQUID, CHEMICALLY INERT TO SAID MALEIC ANHYDRIDE AND POSSESSING THE CHARACTERISTIC OF FORMING A CONSTANT-BOILING MIXTURE WITH SAID MALEIC ANHYDRIDE WITHIN THE RANGE OF 135-190* C., CONTINUOUSLY DISTILLING THE AZEOTRPE OF SAID ORGANIC LIQUID AND MALEIC ANHYDRIDE, RECOVERING SUBSTANTIALLY PURE MALEIC ANHYDRIDE FROM THE EFFLUENT DISTILLATE AND RECYLING THE SAID ORGANIC LIQUID TO FURTHER CONTACT WITH IMPURE MALEIC ANHYDRIDE.
References Cited (Backward Citations)
US1424138A
Cited
US1912628A
Cited
GB415748A
Cited
US2140140A
Cited
US2308588A
Cited
US2683110A
Cited
US2462444A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-02-13 | 1959-08-15 | 1960-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-02-13 | 1963-08-15 | 1964-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-02-13 | 1967-08-15 | 1968-02-14 | $7700.00 | Window Closed / Lapsed |