US2498010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of cellulose esters
Assignee: Celanese Corp
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Filing: 1947-08-28
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Granted: 1950-02-21
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Expires: 1967-08-28
Abstract
No abstract record available.
Inventors
- 👤 George W Seymour
- 👤 Blanche B White
- 👤 Plunguian Mark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:06
CPC Classifications
C; C08; C08B; C08B3/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
115 words
IN A PROCESS FOR THE PRODUCTION OF ORGANIC ACID ESTER OF CELLULOSE WHEREIN CELLULOSE IS ESTERIFIED WITH A LOWER ALIPHATIC ACID ANHDRIDE EMPLOYING AN ACID ESTERFICATION CATALYST, THE STEPS WHICH COMPRISE COOLING THE REACTION MIXTURE BELOW ATMOSPHERIC TEMPERATURE AND EFFECTING THE ESTERIFICATION REACTION IN A PLURALITY OF REACTION STAGES, THE FIRST STAGE BEING CARRIED OUT WITH THE ESTERIFICTION REACTION TEMPERATURE BEING MAINTAINED AT ABOUT 20 TO 40*C. FROM ABOUT 5 TO 40 MINUTES UNTIL THE MAJOR PORTION OF THE CELLULOSE IS ESTERIFIED, THEN RAISING THE REACTION TEMPERATURE TO ABOUT 25 TO 60*C. AND CONTINUING THE ESTERIFICATION REACTION AT THE HIGHER TEMPERATURE FOR FROM 5 TO 40 MINUTES WHEREBY THE ESTERIFICATION OF THE CELLULOSE IS COMPLETED.
Claim 2
Dependent Claim
115 words
IN A PROCESS FOR THE PRODUCTION OF ORGANIC ACID ESTER OF CELLULOSE WHEREIN CELLULOSE IS ESTERIFIED WITH A LOWER ALIPHATIC ACID ANHDRIDE EMPLOYING AN ACID ESTERFICATION CATALYST, THE STEPS WHICH COMPRISE COOLING THE REACTION MIXTURE BELOW ATMOSPHERIC TEMPERATURE AND EFFECTING THE ESTERIFICATION REACTION IN A PLURALITY OF REACTION STAGES, THE FIRST STAGE BEING CARRIED OUT WITH THE ESTERIFICTION REACTION TEMPERATURE BEING MAINTAINED AT ABOUT 20 TO 40*C. FROM ABOUT 5 TO 40 MINUTES UNTIL THE MAJOR PORTION OF THE CELLULOSE IS ESTERIFIED, THEN RAISING THE REACTION TEMPERATURE TO ABOUT 25 TO 60*C. AND CONTINUING THE ESTERIFICATION REACTION AT THE HIGHER TEMPERATURE FOR FROM 5 TO 40 MINUTES WHEREBY THE ESTERIFICATION OF THE CELLULOSE IS COMPLETED.
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) | 1953-02-20 | 1953-08-22 | 1954-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-02-20 | 1957-08-22 | 1958-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-02-20 | 1961-08-22 | 1962-02-21 | $7700.00 | Window Closed / Lapsed |