US3617201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Esterification of cellulosic textiles with sorbic acid in the presence of trifluoroacetic anhydride using controlled cellulose-acid-anhydride ratios
Assignee: United States Department of Agriculture
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Filing: 1969-11-19
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Granted: 1971-11-02
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Expires: 1989-11-19
Abstract
Abstract This invention relates to the production of partial cellulose esters with improved crease recovery through esterification of cellulose with unsaturated fatty acids in the presence of trifluoroacetic anhydride (TFAA) in benzene solution.
Inventors
- 👤 Ralph J Berni
- 👤 Ruth B Benerito
- 👤 John B Mckelvey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:14
CPC Classifications
D; D06; D06M; D06M13/00; D06M13/10; D06M13/184; D06M13/207; D06M13/21; D06M13/213; D06M13/203; D06M13/224; D06M13/236
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3493319A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |