US3240755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of polycarbonates
Assignee: Honeywell International Inc
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Filing: 1960-12-29
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Granted: 1966-03-15
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Expires: 1980-12-29
Abstract
No abstract record available.
Inventors
- 👤 Thomas M Cawthon
- 👤 Bryce C Oxenrider
- 👤 Logan C Bostian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:27
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/22; C08G64/24; C08B; C08B15/00; C08B31/00; C08G64/205; C08G64/40; C09; C09B; C09B62/00; Y; Y10; Y10S; Y10S159/00; Y10S159/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
135 words
A PROCESS FOR THE PRPARATION OF POLYCARBONATE RESINS HAVING A UNIFORM, NARROW MOLECULAR WEIGHT DISTRIBUTION WHICH IS PRESELECTED FROM WITHIN AN AVERAGE MOLECULAR WEIGHT RANGE OF FROM ABOUT 10,000 TO 100,000, WHICH COMPRISES FORMING POLYCARBONATE RESIN BY REATING A MIXTURE CONSISTING ESSENTAILLY OF PHOSGENE AND 2,2-(4,4''-DIHYDROXYDIPHENYL)-PROPANE IN AN AQUEOUS ALKALINE MEDIUM AND IN THE PRESENCE OF A WTER-IMMISCIBLE PARTIAL SOLVENT WHICH IS INERT UNDER THE CONDITIONS OF REACTION AND HAS A COHESIVE ENERGY DENSITY OF FROM ABOUT 65 TO 82, SAID PARTIAL SOLVENT BEING A NON-SILVENT FOR POLYCARBONATE RESINS HAVING MOLECULAR WEIGHT OF AT LEAST ABOUT SAID PRE-SELECTED UNIFORM, NARROW MOLECULAR WEIGHT DISTRIBUTION AND A SOLVENT FOR POLYCARBONATE RESIN HAVING MOLECULAR WEIGHT OF LESS THAN ABOUT SAID PRE-SELECTED UNIFORM, NARROW MOLECULAR WEIGHT DISTRIBUTION, WHEREBY POLYCARBONATE RESIN FORMED HAVING MOLECULAR WEIGHT OF AT LEAST ABOUT SAID
Claim 2
Dependent Claim
135 words
A PROCESS FOR THE PRPARATION OF POLYCARBONATE RESINS HAVING A UNIFORM, NARROW MOLECULAR WEIGHT DISTRIBUTION WHICH IS PRESELECTED FROM WITHIN AN AVERAGE MOLECULAR WEIGHT RANGE OF FROM ABOUT 10,000 TO 100,000, WHICH COMPRISES FORMING POLYCARBONATE RESIN BY REATING A MIXTURE CONSISTING ESSENTAILLY OF PHOSGENE AND 2,2-(4,4''-DIHYDROXYDIPHENYL)-PROPANE IN AN AQUEOUS ALKALINE MEDIUM AND IN THE PRESENCE OF A WTER-IMMISCIBLE PARTIAL SOLVENT WHICH IS INERT UNDER THE CONDITIONS OF REACTION AND HAS A COHESIVE ENERGY DENSITY OF FROM ABOUT 65 TO 82, SAID PARTIAL SOLVENT BEING A NON-SILVENT FOR POLYCARBONATE RESINS HAVING MOLECULAR WEIGHT OF AT LEAST ABOUT SAID PRE-SELECTED UNIFORM, NARROW MOLECULAR WEIGHT DISTRIBUTION AND A SOLVENT FOR POLYCARBONATE RESIN HAVING MOLECULAR WEIGHT OF LESS THAN ABOUT SAID PRE-SELECTED UNIFORM, NARROW MOLECULAR WEIGHT DISTRIBUTION, WHEREBY POLYCARBONATE RESIN FORMED HAVING MOLECULAR WEIGHT OF AT LEAST ABOUT SAID
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) | 1969-03-14 | 1969-09-13 | 1970-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-14 | 1973-09-13 | 1974-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-14 | 1977-09-13 | 1978-03-15 | $7700.00 | Window Closed / Lapsed |