US2596656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of precipitating high acetyl cellulose acetate
Assignee: Eastman Kodak Co
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Filing: 1951-03-06
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Granted: 1952-05-13
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Expires: 1971-03-06
Abstract
No abstract record available.
Inventors
- 👤 Carlton L Crane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:41
CPC Classifications
C; C08; C08B; C08B3/00; C08B3/22; C08B3/26; C08B3/28
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
96 words
IN A PROCESS FOR THE MANUFACTURE OF CELLULOSE ACETATE HAVING AN ACETYL CONTENT OF AT LEAST 42% IN WHICH CELLULOSE IS ESTERIFIED WITH ACETIC ANHYDRIDE AND A SULFURIC ACID CATALYST AND THE TEMPERATURE OF THE COMPLETED ESTERIFICATION MIXTURE IS 80-120* F., THE STEPS OF ADDING TO THE MASS A MIXTURE HEATED TO 180*-190* F. OF AQUEOUS ACETIC ACID CONTAINING 5-21% OF WATER IN AN AMOUNT TO BRING THE MASS TO, BUT NOT SUBSTANTIALLY BEYOND, THE GLACIAL POINT AND A BASIC MAGNESIUM COMPOUND IN AN AMOUNT SUFFICIENT TO COMPLETELY NEUTRALIZE THE SULFURIC ACID IN THE MASS, ACCOM-
References Cited (Backward Citations)
US2469395A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-05-13 | 1955-11-12 | 1956-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-05-13 | 1959-11-12 | 1960-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-05-13 | 1963-11-12 | 1964-05-13 | $7700.00 | Window Closed / Lapsed |