US2865892A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for stabilizing molten polyethylene terephthalate
Assignee: EIDP Inc
•
Filing: 1953-09-30
•
Granted: 1958-12-23
•
Expires: 1973-09-30
Abstract
No abstract record available.
Inventors
- 👤 Izard Emmette Farr
- 👤 Sroog Cyrus Efrem
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:42
CPC Classifications
C; C08; C08J; C08J3/00; C08J2367/00; C08J2367/02; Y; Y10; Y10S; Y10S8/00; Y10S8/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
71 words
A PROCESS FOR STABILIZING THE MOLECULAR WEIGHT OF A POLYETHYLENE TEREPHTHALATE POLYMER IN MOLTEN FORM WHICH COMPRISES MAINTAINING AN UNDEGRADED POLYETHYLENE TEREPHTHALATE AT A TEMPERATURE OF FROM ABOUT 265* TO ABOUT 280*C., AND UNDER A REDUCED PRESSURE WITHIN THE RANGE OF FROM 15 TO 40 MILLIMETERS OF MERCURY, MAINTAINING AN INERT RELATIVELY QUIESCENT, ATMOSPHERE SUBSTANTIALLY FREE OF FREE OXYGEN ABOVE THE SURFACE OF THE MOLTEN POLYMER, AND CONTINUOUSLY STIRRING THE MELT.
Claim 2
Dependent Claim
71 words
A PROCESS FOR STABILIZING THE MOLECULAR WEIGHT OF A POLYETHYLENE TEREPHTHALATE POLYMER IN MOLTEN FORM WHICH COMPRISES MAINTAINING AN UNDEGRADED POLYETHYLENE TEREPHTHALATE AT A TEMPERATURE OF FROM ABOUT 265* TO ABOUT 280*C., AND UNDER A REDUCED PRESSURE WITHIN THE RANGE OF FROM 15 TO 40 MILLIMETERS OF MERCURY, MAINTAINING AN INERT RELATIVELY QUIESCENT, ATMOSPHERE SUBSTANTIALLY FREE OF FREE OXYGEN ABOVE THE SURFACE OF THE MOLTEN POLYMER, AND CONTINUOUSLY STIRRING THE MELT.
References Cited (Backward Citations)
US2503251A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-12-22 | 1962-06-23 | 1962-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-22 | 1966-06-23 | 1966-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-22 | 1970-06-23 | 1970-12-23 | $7700.00 | Window Closed / Lapsed |