Patent US3763113A successfully refreshed from Google Patents.
US3763113A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyamides
Assignee: Celanese Corp
•
Filing: 1966-06-15
•
Granted: 1973-10-02
•
Expires: 1986-06-15
Abstract
Abstract A METHOD FOR INCREASING THE MOLECULAR WEIGHT OF A POLYAMIDE AND THE COMPOSITION PRODUCED THEREBY, COMPRISING HEATING A POLYAMIDE IN THE PRESENCE OF A PHOSPHONIC ACID MATERIAL AT AN ELEVATED TEMPERATURE FOR A PERIOD OF TIME SUFFICIENT TO INCREASE THE RELATIVE VISCOSITY OF THE POLYAMIDE. THE PROCESS IS PARTICULARLY USEFUL FOR FINISHING POLYAMIDE FIBER-FORMING AND MOLDING COMPOSITION TO A HIGH RELATIVE VISCOSITY WHILE AVOIDING UNDERSIRABLE DEGRADATION OF THE POLYMER.
Inventors
- 👤 H Burrows
- 👤 S Hepworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:22
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/49; C08K5/51; C08K5/53; C08K5/5313; C08B; C08B3/00; C08B3/22; C08B3/30; C08G; C08G69/00; C08G69/02; C08G69/04; C08G69/08; C08G69/14; C08G69/16; C08G69/26; C08G69/28; C08K5/5317; C08L; C08L77/00
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) | 1976-10-01 | 1977-04-02 | 1977-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-01 | 1981-04-02 | 1981-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-01 | 1985-04-02 | 1985-10-02 | $7700.00 | Window Closed / Lapsed |