US2789971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polycarbonates from 4, 4'-bis (beta-hydroxyethyl)-biphenyl-bis
Assignee: Eastman Kodak Co
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Filing: 1953-12-08
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Granted: 1957-04-23
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Expires: 1973-12-08
Abstract
No abstract record available.
Inventors
- 👤 Delbert D Reynolds
- 👤 Kenneth R Dunham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:25
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/30; C08G64/16; C08G64/1608
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
19 words
A PROCESS FOR PREPARING A HIGHLY POLYMERIC LINEAR POLYCARBONATE COMPRISING (A) SELF-CONDENSING A BIS(CARBONATE) MONOMER HAVING THE FOLLOWING FORMULA:
Claim 2
Dependent Claim
19 words
A PROCESS FOR PREPARING A HIGHLY POLYMERIC LINEAR POLYCARBONATE COMPRISING (A) SELF-CONDENSING A BIS(CARBONATE) MONOMER HAVING THE FOLLOWING FORMULA:
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-04-22 | 1960-10-22 | 1961-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-22 | 1964-10-22 | 1965-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-22 | 1968-10-22 | 1969-04-23 | $7700.00 | Window Closed / Lapsed |