US3247164A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solubilization of salts of bisphenols in manufacture of polycarbonates
Assignee: Eastman Kodak Co
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Filing: 1961-09-14
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Granted: 1966-04-19
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Expires: 1981-09-14
Abstract
No abstract record available.
Inventors
- 👤 John R Caldwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:30
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/22; C08G64/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
64 words
A PROCESS FOR SYNTHESIS OF POLYCARBONATES COMPRISING THE STEP OF INTIMATELY CONTACTING AN ALKALINE AQUEOUS PHASE TO WHICH A BISPHENOL HAS BEEN ADDED AND AN ORGANIC SOLVENT PHASE TO WHICH HAS BEEN ADDED A DIACID CHLORIDE SELECTED FROM THE GROUP CONSISTING OF PHOSGENE AND DIOL BISCHLOROFORMATES, WHEREIN SAID AQUEOUS PHASE CONSISTS OF A SOLUTION PREPARED BY MIXING WATER, A BISPHENOL HAVING THE GENERAL FORMULA
Claim 2
Dependent Claim
64 words
A PROCESS FOR SYNTHESIS OF POLYCARBONATES COMPRISING THE STEP OF INTIMATELY CONTACTING AN ALKALINE AQUEOUS PHASE TO WHICH A BISPHENOL HAS BEEN ADDED AND AN ORGANIC SOLVENT PHASE TO WHICH HAS BEEN ADDED A DIACID CHLORIDE SELECTED FROM THE GROUP CONSISTING OF PHOSGENE AND DIOL BISCHLOROFORMATES, WHEREIN SAID AQUEOUS PHASE CONSISTS OF A SOLUTION PREPARED BY MIXING WATER, A BISPHENOL HAVING THE GENERAL 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) | 1969-04-18 | 1969-10-18 | 1970-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-04-18 | 1973-10-18 | 1974-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-04-18 | 1977-10-18 | 1978-04-19 | $7700.00 | Window Closed / Lapsed |