Patent US2622079A successfully refreshed from Google Patents.
US2622079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of cellulose acetate sulfate in fibrous form
Assignee: Eastman Kodak Co
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Filing: 1950-12-08
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Granted: 1952-12-16
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Expires: 1970-12-08
Abstract
No abstract record available.
Inventors
- 👤 Carlton L Crane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:29
CPC Classifications
C; C08; C08B; C08B7/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
152 words
A METHOD FOR PREPARING A MIXED ESTER OF CELLULOSE OF SULFURIC ACID AND A LOWER FATTY ACID IN FIBROUS FORM WHICH COMPRISES ESTERIFYING CELLULOSE IN A BATH CONTAINING: (1) 33-275 PARTS OF COMBINED SO4 PER 100 PARTS OF CELLULOSE, 5-50 PER CENT OF THE SO4 BEING IN THE FORM OF FREE SULFURIC ACID AND 95-20 PER CENT OF THE SO4 BEING IN THE FORM OF THE ACID SULFATE; (2) LOWER FATTY ACID AND ANHYDRIDE, THE RATIO OF THE LOWER FATTY ACID AND ANYHDRIDE TO CELLULOSE BEING 4.8-13:1, THE PARTS OF LOWER FATTY ACID ANHYDRIDE BEING AT LEAST THAT INDICATED BY THE EQUATION Y=245-.135X, WHEREIN Y IS THE PARTS OF 100% ACETIC ANHYDRIDE AND X IS THE PARTS OF 100% SULFURIC ACID PER 100 PARTS OF BONE-DRY CELLULOSE, THE MAXIMUM TEMPERATURE OF THE REACTION BEING WITHIN THE RANGE OF 60-80* F., WHEREBY THE CELLULOSE IS ESTERIFIED WITHOUT BECOMING DISSOLVED IN THE ESTERIFICATION MASS.
Claim 2
Independent Claim
152 words
A METHOD FOR PREPARING A MIXED ESTER OF CELLULOSE OF SULFURIC ACID AND A LOWER FATTY ACID IN FIBROUS FORM WHICH COMPRISES ESTERIFYING CELLULOSE IN A BATH CONTAINING: (1) 33-275 PARTS OF COMBINED SO4 PER 100 PARTS OF CELLULOSE, 5-50 PER CENT OF THE SO4 BEING IN THE FORM OF FREE SULFURIC ACID AND 95-20 PER CENT OF THE SO4 BEING IN THE FORM OF THE ACID SULFATE; (2) LOWER FATTY ACID AND ANHYDRIDE, THE RATIO OF THE LOWER FATTY ACID AND ANYHDRIDE TO CELLULOSE BEING 4.8-13:1, THE PARTS OF LOWER FATTY ACID ANHYDRIDE BEING AT LEAST THAT INDICATED BY THE EQUATION Y=245-.135X, WHEREIN Y IS THE PARTS OF 100% ACETIC ANHYDRIDE AND X IS THE PARTS OF 100% SULFURIC ACID PER 100 PARTS OF BONE-DRY CELLULOSE, THE MAXIMUM TEMPERATURE OF THE REACTION BEING WITHIN THE RANGE OF 60-80* F., WHEREBY THE CELLULOSE IS ESTERIFIED WITHOUT BECOMING DISSOLVED IN THE ESTERIFICATION MASS.
References Cited (Backward Citations)
US1866532A
Cited
US2582009A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-12-16 | 1956-06-16 | 1956-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-12-16 | 1960-06-16 | 1960-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-12-16 | 1964-06-16 | 1964-12-16 | $7700.00 | Window Closed / Lapsed |