Patent US3810870A successfully refreshed from Google Patents.
US3810870A
Expired / Lapsed
US
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Aromatic polyethers
Assignee: Imperial Chemical Industries Ltd
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Filing: 1972-05-12
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Granted: 1974-05-14
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Expires: 1992-05-12
Abstract
Abstract A POLYMER IS PROVIDED HAVING RECURRING UNITS OF THE FORMULA -(NAPHTH-1,4-YLENE)-O-E-(NAPHTH-1,4-YLENE)- WHERE E IS PREFERABLY A DIRECT LINK OR MAY BE A GROUP HAVING THE FORMULA -X-O- WHERE X IS DIVALENT NONPOLAR RESIDUE.
Inventors
- 👤 R Feasey
- 👤 J Freeman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:17
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/04; C08G64/06; C08G61/00; C08G61/12
Claims Analysis
Total Claims: 0
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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) | 1977-05-13 | 1977-11-12 | 1978-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-13 | 1981-11-12 | 1982-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-13 | 1985-11-12 | 1986-05-14 | $7700.00 | Window Closed / Lapsed |