US2957849A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for stabilizing polypropylene
Assignee: Sunoco Inc
•
Filing: 1957-03-27
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Granted: 1960-10-25
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Expires: 1977-03-27
Abstract
No abstract record available.
Inventors
- 👤 Robert M Kennedy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:10
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/0008; C08K5/005
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
55 words
PROCESS FOR THE PREPARATION OF STABILIZED POLYPROPYLENE WHICH COMPRISES ADMIXING SOLID POLYPROPYLENE WITH A STABILIZER THEREOF, SUBJECTING THE RESULTING MIXTURE TO A VACUUM EFFECTIVE TO REMOVE SUBSTANTIALLY ALL OXYGEN, MAINTAINING THE MIXTURE IN SAID VACUUM WHILE HEATING THE MIXTURE TO A TEMPERATURE NOT SUBSTANTIALLY HIGHER THAN ABOUT 30* C. ABOVE THE MELTING POINT OF THE
Claim 2
Dependent Claim
55 words
PROCESS FOR THE PREPARATION OF STABILIZED POLYPROPYLENE WHICH COMPRISES ADMIXING SOLID POLYPROPYLENE WITH A STABILIZER THEREOF, SUBJECTING THE RESULTING MIXTURE TO A VACUUM EFFECTIVE TO REMOVE SUBSTANTIALLY ALL OXYGEN, MAINTAINING THE MIXTURE IN SAID VACUUM WHILE HEATING THE MIXTURE TO A TEMPERATURE NOT SUBSTANTIALLY HIGHER THAN ABOUT 30* C. ABOVE THE MELTING POINT OF THE
References Cited (Backward Citations)
US2776274A
Cited
US2255729A
Cited
US2806009A
Cited
US2824090A
Cited
US2880201A
Cited
US2835659A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-10-25 | 1964-04-25 | 1964-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-10-25 | 1968-04-25 | 1968-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-10-25 | 1972-04-25 | 1972-10-25 | $7700.00 | Window Closed / Lapsed |