Patent US2989501A successfully refreshed from Google Patents.
US2989501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bisphenol polyoxalates
Assignee: EIDP Inc
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Filing: 1958-02-27
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Granted: 1961-06-20
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Expires: 1978-02-27
Abstract
No abstract record available.
Inventors
- 👤 Stamatoff Gelu Stoeff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:40
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/16; C08G63/18; C08G63/19; C08G63/193
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
88 words
A NOVEL BIS(4-HYDROXYPHENYL)-2,2-PROPANE POLYOXALATE, CHARACTERIZED IN THAT IT HAS AN INHERENT VISCOSITY IN THE RANGE OF 0.4 TO 1.0, MEASURED IN CHLOROFORM AT 0.5% CONCENTRATION AT 35* C., AND IS OBTAINED BY HEATING BIS(4HYDROXYPHENYL)-2,2-PROPANE WITH A DIARYL OXALATE OF THE FORMULA (COOR)2 IN EQUIMOLAL PROPORTIONS, R BEING A MONOCYCLIC ARYL HYDROCARBON RADICAL, UNTIL ALL OF THE RESULTING PHENOL OF THE FORMULA ROH IS REMOVED FROM THE SYSTEM, FOLLOWED BY FURTHER HEATING THE RESULTANT POLYOXALATE AT A TEMPERATURE OF 250* TO 325* C. UNTIL A CHLOROFORM-SOLUBLE PRODUCT IS OBTAINED.
Claim 2
Dependent Claim
88 words
A NOVEL BIS(4-HYDROXYPHENYL)-2,2-PROPANE POLYOXALATE, CHARACTERIZED IN THAT IT HAS AN INHERENT VISCOSITY IN THE RANGE OF 0.4 TO 1.0, MEASURED IN CHLOROFORM AT 0.5% CONCENTRATION AT 35* C., AND IS OBTAINED BY HEATING BIS(4HYDROXYPHENYL)-2,2-PROPANE WITH A DIARYL OXALATE OF THE FORMULA (COOR)2 IN EQUIMOLAL PROPORTIONS, R BEING A MONOCYCLIC ARYL HYDROCARBON RADICAL, UNTIL ALL OF THE RESULTING PHENOL OF THE FORMULA ROH IS REMOVED FROM THE SYSTEM, FOLLOWED BY FURTHER HEATING THE RESULTANT POLYOXALATE AT A TEMPERATURE OF 250* TO 325* C. UNTIL A CHLOROFORM-SOLUBLE PRODUCT IS OBTAINED.
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) | 1964-06-19 | 1964-12-19 | 1965-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-19 | 1968-12-19 | 1969-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-19 | 1972-12-19 | 1973-06-20 | $7700.00 | Window Closed / Lapsed |