US3794629A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized aromatic polycarbonates
Assignee: Bayer AG
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Filing: 1972-08-09
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Granted: 1974-02-26
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Expires: 1992-08-09
Abstract
Abstract AROMATIC POLYCARBONATES HAVING ADDED A NEUTRAL ESTER OF PHOSPHOROUS ACID WITH AT LEAST ONE OXETANE GROUP, THE LATTER FUNCTIONS AS A STABILIZER FOR THE POLYCARBONATE TO LESSEN DISCOLORATION AFTER EXPOSURE TO HEAT. THUS, THE POLYCARBONATES OF THE INVENTION ARE PARTICULARLY USEFUL IN THE LIGHTING FIELD.
Inventors
- 👤 E Eimers
- 👤 H Schmid
- 👤 D Margotte
- 👤 R Dhein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:07
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/547; C07F9/655; C07F9/6551; C08; C08K; C08K5/00; C08K5/49; C08K5/51; C08K5/52; C08K5/529
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |