US3705874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of polyhydantoin plastics containing imide groups
Assignee: Bayer AG
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Filing: 1971-06-08
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Granted: 1972-12-12
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Expires: 1991-06-08
Abstract
Abstract POLYHYDANTOIN PLASTICS CONTAINING IMIDE-UNITS AND A PROCESS FOR THEIR PRODUCTION BY REACTION OF IN A FIRST STAGE A POLYVALENT GLYCINE ESTER DERIVATIVE WITH AN EXCESS OF A POLYISOCYANATE AND IN A SECOND STAGE THE PREADDUCT THUS OBTAINED WITH A POLYVALENT COMPOUND CONTAINING AT LEAST ONE CYCLIC CARBOXYLIC ACID ANHYDRIDE GROUP.
Inventors
- 👤 Rudolf Merten
- 👤 Wilfried Zecher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:19
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/38; C08G18/3819; C08G18/3821; C08G18/3823; C08G18/3825; Y; Y10; Y10S; Y10S260/00; Y10S260/34; Y10S528/00; Y10S528/906
Claims Analysis
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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) | 1975-12-12 | 1976-06-12 | 1976-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-12 | 1980-06-12 | 1980-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-12 | 1984-06-12 | 1984-12-12 | $7700.00 | Window Closed / Lapsed |