US2970131A
Expired / Lapsed
US
⏱️ 0.0 years remaining
polycarbonate process
Assignee: —
•
Filing: —
•
Granted: 1961-01-31
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Expires: 1978-01-31
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:59
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/22; C08G64/24; C08G64/04; C08G64/06; C08G64/14; C08G64/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
61 words
A PROCESS FOR PREPARING SUBSTANTIALLY LINEAR, THERMOPLASTIC POLYCARBONATE RESINS WHICH COMPRISES REATING A DI(MONOHYDROXY-PHENYL)-SUBSTITUTED ALIPHATIC HYDROCARBON, IN WHICH BOTH HYDROXY-PHENYL GROUPS ARE ATTACHED TO THE SAME CARBON WITH PHOSGENE IN THE PRESENCE OF AN ALKALI METAL HYDROXIDE, SAID ALKALI METAL HYDROXIDE BEING PRESENT IN AN AMOUNT SUFFICIENT TO IMPART TO THE REACTION SYSTEM A PH VALUE BETWEEN ABOUT 10.5 TO 11.55.
Claim 2
Dependent Claim
61 words
A PROCESS FOR PREPARING SUBSTANTIALLY LINEAR, THERMOPLASTIC POLYCARBONATE RESINS WHICH COMPRISES REATING A DI(MONOHYDROXY-PHENYL)-SUBSTITUTED ALIPHATIC HYDROCARBON, IN WHICH BOTH HYDROXY-PHENYL GROUPS ARE ATTACHED TO THE SAME CARBON WITH PHOSGENE IN THE PRESENCE OF AN ALKALI METAL HYDROXIDE, SAID ALKALI METAL HYDROXIDE BEING PRESENT IN AN AMOUNT SUFFICIENT TO IMPART TO THE REACTION SYSTEM A PH VALUE BETWEEN ABOUT 10.5 TO 11.55.
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) | 1964-01-31 | 1964-08-01 | 1965-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-01-31 | 1968-08-01 | 1969-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-01-31 | 1972-08-01 | 1973-01-31 | $7700.00 | Window Closed / Lapsed |