Patent US2600716A successfully refreshed from Google Patents.
US2600716A
Expired / Lapsed
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Preparation of cellulose esters
Assignee: Celanese Corp
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Filing: 1948-09-09
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Granted: 1952-06-17
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Expires: 1968-09-09
Abstract
No abstract record available.
Inventors
- 👤 Blanche B White
- 👤 Leonard J Rosen
- 👤 Blackman Peter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:57
CPC Classifications
C; C08; C08B; C08B3/00; C08B3/22; C08B3/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
88 words
PROCESS FOR TREATING CELLULOSE PROPIONATE, WHICH COMPRISES RIPENING SAID CELLULOSE PROPIONATE AT A PRESSURE OF ABOUT 150 POUNDS PER SQUARE INCH AT A TEMPERATURE OF ABOUT 155* C., AND SUBJECTING A MIXTURE OF 10 PARTS BY WEIGHT OF SAID RIPENED CELLULOSE PROPIONATE IN SOLID FORM AND 100 PARTS BY WEIGHT OF DILUTE PROPIONIC ACID HAVING AN ACID CONCENTRATION OF ABOUT 20% BY WEIGHT, TO SUPER-ATMOSPHERIC PRESSURE OF ABOUT 25 POUNDS PER SQUARE INCH, AT A TEMPERATURE OF ABOUT 130* C. WHEREBY SAID CELLULOSE PROPIONATE IS RENDERED MORE STABLE.
Claim 2
Dependent Claim
88 words
PROCESS FOR TREATING CELLULOSE PROPIONATE, WHICH COMPRISES RIPENING SAID CELLULOSE PROPIONATE AT A PRESSURE OF ABOUT 150 POUNDS PER SQUARE INCH AT A TEMPERATURE OF ABOUT 155* C., AND SUBJECTING A MIXTURE OF 10 PARTS BY WEIGHT OF SAID RIPENED CELLULOSE PROPIONATE IN SOLID FORM AND 100 PARTS BY WEIGHT OF DILUTE PROPIONIC ACID HAVING AN ACID CONCENTRATION OF ABOUT 20% BY WEIGHT, TO SUPER-ATMOSPHERIC PRESSURE OF ABOUT 25 POUNDS PER SQUARE INCH, AT A TEMPERATURE OF ABOUT 130* C. WHEREBY SAID CELLULOSE PROPIONATE IS RENDERED MORE STABLE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-06-17 | 1955-12-17 | 1956-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-06-17 | 1959-12-17 | 1960-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-06-17 | 1963-12-17 | 1964-06-17 | $7700.00 | Window Closed / Lapsed |