Patent US3223677A successfully refreshed from Google Patents.
US3223677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing polycarbonates
Assignee: Union Carbide Corp
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Filing: 1963-07-02
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Granted: 1965-12-14
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Expires: 1983-07-02
Abstract
No abstract record available.
Inventors
- 👤 Matzner Markus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:33
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/22; C08G64/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
90 words
PROCESS FOR PREPARING POLYCARBONE RESINS WHICH COMPRISES DISSOLVING A DIHYDRIC PHENOL, PHOSGENE AND A CATALYTIC AMOUNT OF A FRIEDEL-CRAFTS CATALYST IN AN INERT LIQUID ORGANIC SOLVENT TO FORM A REACTION MIXTURE AT A TEMPERATURE BELOW THE BOILING POINT OF THE MIXTURE, HEATING THE MIXTURE AT JEST THE BOILING POINT, REMOVING HE HCL EVOLVED, CONTINUING HEATING THE MIXTURE AT HIGHER TEMPERATURES AS PHOSGENE IS CONSUMED BUT JUST AT THE BOILING POINT OF THE MIXTURE AND FINALLY HEATING THE MIXTURE UNTIL THE BOILING POINT OF THE SOLVENT AT OPERATING PRESSURES IS REACHED.
Claim 2
Dependent Claim
90 words
PROCESS FOR PREPARING POLYCARBONE RESINS WHICH COMPRISES DISSOLVING A DIHYDRIC PHENOL, PHOSGENE AND A CATALYTIC AMOUNT OF A FRIEDEL-CRAFTS CATALYST IN AN INERT LIQUID ORGANIC SOLVENT TO FORM A REACTION MIXTURE AT A TEMPERATURE BELOW THE BOILING POINT OF THE MIXTURE, HEATING THE MIXTURE AT JEST THE BOILING POINT, REMOVING HE HCL EVOLVED, CONTINUING HEATING THE MIXTURE AT HIGHER TEMPERATURES AS PHOSGENE IS CONSUMED BUT JUST AT THE BOILING POINT OF THE MIXTURE AND FINALLY HEATING THE MIXTURE UNTIL THE BOILING POINT OF THE SOLVENT AT OPERATING PRESSURES IS REACHED.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-12-13 | 1969-06-14 | 1969-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-13 | 1973-06-14 | 1973-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-13 | 1977-06-14 | 1977-12-14 | $7700.00 | Window Closed / Lapsed |