US3634355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aromatic polymers from dihalogenoben-zenoid compounds and alkali metal hydroxide
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1968-03-21
•
Granted: 1972-01-11
•
Expires: 1988-03-21
Abstract
Abstract AROMATIC POLYMERS CONTAINING BENZENOID GROUPS AND OXYGEN ATOMS IN THE POLYMER CHAINS ARE MADE BY THE ACTION OF AN ALKALI METAL HYDROXIDE ON A DIHALOGENOBENZENOID COMPOUND IN WHICH EACH HALOGEN ATOM IS ACTIVATED BY AN INERT ELECTRON-ATTRACTING GROUP SUCH AS -SO2-. WHEN A BIS-(4-HALOGENOPHENYL) SULPHONE IS REACTED WITH AN ALKALI METAL HYDROXIDE, THE ALKALI METAL SALT OF A 4-(4-HALOGENOPHENYLSULPHONYL) PHENOL IS FORMED AS A READILY ISOLATED INTERMEDIATE WHICH POLYMERISES IN THE PRESENCE OR SOLVENT TO GIVE A POLYMER HAVING REPEATING UNITS OF THE STRUCTURE -(1,4-PHENYLENE-SO2-1,4-PHENYLENE-O
Inventors
- 👤 Dennis Arthur Barr
- 👤 John Brewster Rose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:24
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/34; C08G65/38
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |