US3022271A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Finishing of solid diphenolic polycarbonates
Assignee: PPG Industries Inc
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Filing: 1960-08-10
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Granted: 1962-02-20
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Expires: 1980-08-10
Abstract
No abstract record available.
Inventors
- 👤 Donald E Darr
- 👤 Richard P Naworski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:20
CPC Classifications
B; B29; B29B; B29B13/00; B29B13/06; B29B7/00; B29B7/30; B29B7/34; B29B7/38; B29B7/46; B29B7/48; B29B7/482; B29B7/484; B29B7/80; B29B7/84; B29B7/845; B29C; B29C48/00; B29C48/25; B29C48/268; B29C48/36; B29C48/50; B29C48/505; B29C48/63; B29C48/76; B29C48/765; B29C48/766; B29C48/767; C; C08; C08G; C08G64/00; C08G64/20; C08G64/205; B29C48/03; Y; Y10; Y10S; Y10S159/00; Y10S159/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
91 words
A METHOD OF RECOVERING SOLID POLYCARBONATE OF A DIPHENOL FROM SOLUTION IN INERT SOLVENT NORMALLY BOILING BELOW THE TEMPERATURE AT WHICH THE POLYCARBONATE IS FLOWABLE WHICH COMPRISES HEATING THE SOLUTION TO VOLATILIZE SOLVENT THEREFROM AND RAISE THE SOLUTION TO A TEMPERATURE AT WHICH THE POLYCARBONATE IS FLOWABLE WHILE MAINTAINING SUPERATMOSPHERIC PRESSURE UPON THE SOLUTION SUFFICIENT TO CONTROL THE VOLATILIZATION SO AS TO RETAIN WITH THE POLYCARBONATE SUFFICIENT SOLVENT TO KEEP THE POLYCARBONATE-SOLVENT MIXTURE FLOWABLE UNTIL ATTAINING A TEMPERATURE AT WHICH THE POLYCARBONATE IS FLOWABLE AND THEREAFTER EXTRUDING THE SOLVENT-LEAN FLOWABLE POLYCARBONATE.
Claim 2
Independent Claim
91 words
A METHOD OF RECOVERING SOLID POLYCARBONATE OF A DIPHENOL FROM SOLUTION IN INERT SOLVENT NORMALLY BOILING BELOW THE TEMPERATURE AT WHICH THE POLYCARBONATE IS FLOWABLE WHICH COMPRISES HEATING THE SOLUTION TO VOLATILIZE SOLVENT THEREFROM AND RAISE THE SOLUTION TO A TEMPERATURE AT WHICH THE POLYCARBONATE IS FLOWABLE WHILE MAINTAINING SUPERATMOSPHERIC PRESSURE UPON THE SOLUTION SUFFICIENT TO CONTROL THE VOLATILIZATION SO AS TO RETAIN WITH THE POLYCARBONATE SUFFICIENT SOLVENT TO KEEP THE POLYCARBONATE-SOLVENT MIXTURE FLOWABLE UNTIL ATTAINING A TEMPERATURE AT WHICH THE POLYCARBONATE IS FLOWABLE AND THEREAFTER EXTRUDING THE SOLVENT-LEAN FLOWABLE POLYCARBONATE.
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) | 1965-02-19 | 1965-08-21 | 1966-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-02-19 | 1969-08-21 | 1970-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-02-19 | 1973-08-21 | 1974-02-20 | $7700.00 | Window Closed / Lapsed |