US3635909A
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US
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Method for polymerizing alpha-amino acid n - carboxyanhydrides using alkali metal salts of 2-pyrrolidone
Assignee: KH Neochem Co Ltd
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Filing: 1970-06-02
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Granted: 1972-01-18
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Expires: 1990-06-02
Abstract
Abstract THE POLYMERIZATION OF A-AMINO ACID N-CARBOXYAHYDRIDES IS CARRIED OUT IN THE PRESENCE OF AN ALKALI METAL SALT OF 2-PYRROLIDONE OR DERRIVATES THEREOF TO PRODUCE AMINO ACID POLYMERS.
Inventors
- 👤 Yasuo Fujimoto
- 👤 Keizo Tatsukawa
- 👤 Toru Doiuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:08
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |