US2946766A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing polycarbonates
Assignee: Bayer AG
•
Filing: 1956-07-09
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Granted: 1960-07-26
•
Expires: 1976-07-09
Abstract
No abstract record available.
Inventors
- 👤 Schnell Hermann
- 👤 Fritz Gerhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:33
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/04; C08G64/06; C08G64/20; C08G64/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
90 words
A PROCESS FOR PRODUCING HIGH MOLECULAR WEIGHT FILM AND FIBER-FORMING RESINOUS LINEAR POLYCARBONATES, WHICH CONSISTS ESSENTIALLY OF HEATING AT A TEMPERATURE BETWEEN 120 AND 280*C., AND AT A REDUCED PRESSURE A COMPOSITION THAT CONSISTS ESSENTIALLY OF (I) A COMPOUND SELECTED FROM THE CLASS CONSISTING OF ARYL, ALKLY AND CYCLOALKYL DIESTERS OF THE BIS-MONOCARBONATES OF AROMATIC DIHYDROXY HYDROCARBONS, AND (II) NO MOTE THAN AN EQUIMOLAR AMOUNT OF AN UNESTERIFIED AROMATIC DIHYDROXY COMPOUND, AND CONTINUING THE HEATING FOR A TIME SUFFICIENT TO CAUSE LINEAR INTERESTERIFICATION AND THE FORMATION OF THE DESIRED POLYCARBONATE.
Claim 2
Dependent Claim
90 words
A PROCESS FOR PRODUCING HIGH MOLECULAR WEIGHT FILM AND FIBER-FORMING RESINOUS LINEAR POLYCARBONATES, WHICH CONSISTS ESSENTIALLY OF HEATING AT A TEMPERATURE BETWEEN 120 AND 280*C., AND AT A REDUCED PRESSURE A COMPOSITION THAT CONSISTS ESSENTIALLY OF (I) A COMPOUND SELECTED FROM THE CLASS CONSISTING OF ARYL, ALKLY AND CYCLOALKYL DIESTERS OF THE BIS-MONOCARBONATES OF AROMATIC DIHYDROXY HYDROCARBONS, AND (II) NO MOTE THAN AN EQUIMOLAR AMOUNT OF AN UNESTERIFIED AROMATIC DIHYDROXY COMPOUND, AND CONTINUING THE HEATING FOR A TIME SUFFICIENT TO CAUSE LINEAR INTERESTERIFICATION AND THE FORMATION OF THE DESIRED POLYCARBONATE.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-07-26 | 1964-01-25 | 1964-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-07-26 | 1968-01-25 | 1968-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-07-26 | 1972-01-25 | 1972-07-26 | $7700.00 | Window Closed / Lapsed |