US2759787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cellulose citrates and their preparation
Assignee: Eastman Kodak Co
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Filing: 1953-05-15
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Granted: 1956-08-21
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Expires: 1973-05-15
Abstract
No abstract record available.
Inventors
- 👤 George P Touey
- 👤 John E Kiefer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:42
CPC Classifications
C; C08; C08B; C08B3/00; C08B3/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
36 words
CELLULOSE ACID CITRATE HAVING A FREE CARBOXYL CONTENT OF 1-15.5% WHICH ESTER IS CHARACTERIZED BY BEING INSOLUBLE BOTH IN THE FORM OF THE FREE ACID AND OF ITS SALT IN WATER ORGANIC SOLVENTS AND AQUEOUS ALKALIES.
Claim 2
Dependent Claim
36 words
CELLULOSE ACID CITRATE HAVING A FREE CARBOXYL CONTENT OF 1-15.5% WHICH ESTER IS CHARACTERIZED BY BEING INSOLUBLE BOTH IN THE FORM OF THE FREE ACID AND OF ITS SALT IN WATER ORGANIC SOLVENTS AND AQUEOUS ALKALIES.
Claim 3
Independent Claim
41 words
A METHOD OF PREPARING CELLULOSE ACID CITRATES INSOLUBLE IN WATER AND ORGANIC SOLVENTS IN THE FORM OF BOTH THE FREE ACID AND ITS SALT WHICH COMPRISES HEATING AN INTIMATE MIXTURE OF CELLULOSE AND CITRIC ACID AT 60-180* C. FOR 1-24 HOURS.
Claim 4
Independent Claim
41 words
A METHOD OF PREPARING CELLULOSE ACID CITRATES INSOLUBLE IN WATER AND ORGANIC SOLVENTS IN THE FORM OF BOTH THE FREE ACID AND ITS SALT WHICH COMPRISES HEATING AN INTIMATE MIXTURE OF CELLULOSE AND CITRIC ACID AT 60-180* C. FOR 1-24 HOURS.
References Cited (Backward Citations)
US2146755A
Cited
GB534894A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-08-21 | 1960-02-20 | 1960-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-08-21 | 1964-02-20 | 1964-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-08-21 | 1968-02-20 | 1968-08-21 | $7700.00 | Window Closed / Lapsed |