Patent US3787372A successfully refreshed from Google Patents.
US3787372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of aromatic copolyamide-phosphonamides
Assignee: Hoechst AG
•
Filing: 1971-12-16
•
Granted: 1974-01-22
•
Expires: 1991-12-16
Abstract
Abstract NEW FILM- AND FIBER-FORMING HIGH MOLECULAR WEIGHT AROMATIC COPOLYAMIDE-PHOSPHONAMIDES ARE OBTAINED BY ADDING A PHOSPHONIC ACID DIHALIDE AT ELEVATED TEMPERATURE TO A MELT OF AT LEAST ONE AROMATIC DIAMINE IN EXCESS, BY DISSOLVING THE REACTION PRODUCT, AFTER COMPELTE REACTION, IN A SOLVENT OF THE AMIDE KIND, BY ADDING AT LEAST ONE AROMATIC DICARBOXYLIC ACID HALIDE TO THIS SOLUTION AT A TEMPERATURE OF FROM ABOUT -20* TO +30*C., AND THUS POLYCONDNESING IT TO FORM A HIGH MOLECULAR WEIGHT AROMATIC COPOLYAMIDE-PHOSPHONAMIDE. SHAPED ARTICLES MADE FROM THESE COPOLYAMIDE-PHOSPHONAMIDES ARE DISTINGUISHED BY THEIR GOOD AFFINITY TO DYESTUFFS AND POOR FLAMMABILITY.
Inventors
- 👤 E Blocker
- 👤 P Eckardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:40
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/32; C08G79/00; C08G79/02; Y; Y10; Y10S; Y10S8/00; Y10S8/92; Y10S8/924
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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |