Patent US1445907A successfully refreshed from Google Patents.
Patent US2587623A successfully refreshed from Google Patents.
US2587623A
Expired / Lapsed
US
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Acylation of dextran in formamide
Assignee: United States Department of Agriculture
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Filing: 1951-01-16
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Granted: 1952-03-04
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Expires: 1971-01-16
Abstract
No abstract record available.
Inventors
- 👤 Allene R Jeanes
- 👤 Carl A Wilham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:17
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0009; C08B37/0021
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
44 words
THE METHOD COMPRISING DISSOLVING DEXTRAN IN FORMAMIDE AND THEREAFTER ACETYLATING THE DISSOLVED DEXTRAN WITH ACETIC ANHYDRIDE IN THE PRESENCE OF PYRIDINE AT A TEMPERATURE OF ABOUT FROM 15* C. TO 30* C. TO PRODUCE DEXTRAN TRIACETATE CHARACTERIZED IN THAT IT IS SOLUBLE IN TETRACHLOROETHANE.
Claim 2
Independent Claim
44 words
THE METHOD COMPRISING DISSOLVING DEXTRAN IN FORMAMIDE AND THEREAFTER ACETYLATING THE DISSOLVED DEXTRAN WITH ACETIC ANHYDRIDE IN THE PRESENCE OF PYRIDINE AT A TEMPERATURE OF ABOUT FROM 15* C. TO 30* C. TO PRODUCE DEXTRAN TRIACETATE CHARACTERIZED IN THAT IT IS SOLUBLE IN TETRACHLOROETHANE.
References Cited (Backward Citations)
US2538903A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-03-04 | 1955-09-03 | 1956-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-03-04 | 1959-09-03 | 1960-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-03-04 | 1963-09-03 | 1964-03-04 | $7700.00 | Window Closed / Lapsed |