US3262913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing polycarbonates
Assignee: Fujifilm Holdings Corp
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Filing: 1963-07-08
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Granted: 1966-07-26
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Expires: 1983-07-08
Abstract
No abstract record available.
Inventors
- 👤 Chiba Toshio
- 👤 Izuka Masao
- 👤 Tsuji Nobuo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:53
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/26; C08G64/28; C08G64/22; C08G64/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
63 words
A PROCESS FOR THE PRODUCTION OF A POLYCARBONATE WHICH COMPRISES CONDENSATION-REACTING A BIS(MONOHYDROXYARYL)-ALKANE WITH A COMPOUND SELECTED FROM THE CLASS CONSISTING OF PHOSGENE AND A BIS-CHLORO-CARBONIC ACID ESTER OF A BIS-(MONOHYDROXYARYL)-ALKANE IN THE PRESENCE OF AN ACID-ACCEPTOR CONSISTING OF A CAUSTIC ALKALI AND IN THE PRESENCE OF A CATALYST SELECTED FROM THE CLASS CONSISTING OF THOSE ACID AMIDES REPRESENTED BY THE FOLLOWING FORMULAS
Claim 2
Dependent Claim
63 words
A PROCESS FOR THE PRODUCTION OF A POLYCARBONATE WHICH COMPRISES CONDENSATION-REACTING A BIS(MONOHYDROXYARYL)-ALKANE WITH A COMPOUND SELECTED FROM THE CLASS CONSISTING OF PHOSGENE AND A BIS-CHLORO-CARBONIC ACID ESTER OF A BIS-(MONOHYDROXYARYL)-ALKANE IN THE PRESENCE OF AN ACID-ACCEPTOR CONSISTING OF A CAUSTIC ALKALI AND IN THE PRESENCE OF A CATALYST SELECTED FROM THE CLASS CONSISTING OF THOSE ACID AMIDES REPRESENTED BY THE FOLLOWING FORMULAS
References Cited (Backward Citations)
US2964797A
Cited
US3148985A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-07-25 | 1970-01-24 | 1970-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-07-25 | 1974-01-24 | 1974-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-07-25 | 1978-01-24 | 1978-07-26 | $7700.00 | Window Closed / Lapsed |