US3830781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
4-hydroxy-3,3',4'-trichlorodiphenyl sulphone
Assignee: Imperial Chemical Industries Ltd
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Filing: 1973-01-15
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Granted: 1974-08-20
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Expires: 1993-01-15
Abstract
Abstract NEW AROMATIC POLYMERS WHOSE MOLECULAR CHAINS COMPRISE UNITS OF THE FORMULA -O-(2-(CL-)-1,4-PHENYLENE)-SO2-(3-(CL-)-1,4-PHENYLENE)EITHER ALONE OR COPOLYMERISED WITH OTHER UNITS, AND IN PARTICULAR WITH UNITS OF THE FORMULA -O-1,4-PHENYLENE-SO2-1,4-PHENYLENEPOLYMERS CONTAINING UNITS OF THE FORMER FORMULA ARE OF HIGHER FIRE RESISTANCE THAN EQUIVALENT POLYMERS HAVING UNITS OF THE LATTER FORMULA ALONE.
Inventors
- 👤 V Leslie
- 👤 J Rose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:19
CPC Classifications
C; C08; C08G; C08G75/00; C08G75/20; C08G75/23; C07; C07C; C07C309/00; C07C309/78; C07C309/86; C07C317/00; C07C317/14; C07C317/16; C07C317/22; C08G65/00; C08G65/34; C08G65/38
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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |