Patent US3291774A successfully refreshed from Google Patents.
US3291774A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polycarbonates from diphenolic acids
Assignee: Armstrong World Industries Inc
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Filing: 1960-10-07
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Granted: 1966-12-13
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Expires: 1980-10-07
Abstract
No abstract record available.
Inventors
- 👤 Nicholas C Bolgiano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:01
CPC Classifications
C; C08; C08G; C08G64/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
75 words
AN ALKALI SOLUBLE POLYCARBONATE PREPARED BY THE REACTION OF, IN AN AQUEOUS MEDIUM AT A PH OF FROM ABOUT 10-11, (A) A MEMBER THE SOLE REACTIVE GROUPS OF WHICH ARE, UNDER THE CONDITIONS OF THE CONDENSATION REACTION, THE PHENYL HYDROXY GROUPS, SAID MEMBER BEING SELECTED FROM THE CLASS CONSISTING OF ADIPHENOLIC ACID AND A MIXTURE OF BISPHENOLS OF WHICH AT LEAST 5 MOLS PERCENT IS A DIPHENOLIC ACID, SAID DIPHENOLIC ACID BEING OF THE FORMULA
Claim 2
Dependent Claim
75 words
AN ALKALI SOLUBLE POLYCARBONATE PREPARED BY THE REACTION OF, IN AN AQUEOUS MEDIUM AT A PH OF FROM ABOUT 10-11, (A) A MEMBER THE SOLE REACTIVE GROUPS OF WHICH ARE, UNDER THE CONDITIONS OF THE CONDENSATION REACTION, THE PHENYL HYDROXY GROUPS, SAID MEMBER BEING SELECTED FROM THE CLASS CONSISTING OF ADIPHENOLIC ACID AND A MIXTURE OF BISPHENOLS OF WHICH AT LEAST 5 MOLS PERCENT IS A DIPHENOLIC ACID, SAID DIPHENOLIC ACID BEING OF THE FORMULA
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) | 1969-12-12 | 1970-06-13 | 1970-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-12-12 | 1974-06-13 | 1974-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-12-12 | 1978-06-13 | 1978-12-13 | $7700.00 | Window Closed / Lapsed |