US2852508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Precipitation of dicarboxylic acid esters of cellulose ethers and lower fatty acid esters
Assignee: Eastman Kodak Co
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Filing: 1956-03-20
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Granted: 1958-09-16
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Expires: 1976-03-20
Abstract
No abstract record available.
Inventors
- 👤 Gordon D Hiatt
- 👤 Carlton L Crane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:48
CPC Classifications
C; C08; C08B; C08B13/00; C08B3/00; C08B3/22; C08B3/26; C08B3/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
A METHOD OF PREPARING CELLULOSE DIACARBOXYLIC ACID ESTERS WHICH COMPRISES REACTING UPON A CELLULOSE MATERIAL SELECTED FROM THE GROUP CONSISTING OF THE CELLULOSE ETHERS AND THE LOWER FATTY ACID ESTERS OF CELLULOSE CONTAINING FREE AND ESTERIFIABLE HYDROXYL GROUPS WITH A BATH ESSENTIALLY CONSISTING OF NOT MORE THAN 3 PARTS OF DICARBOXYLIC ACID ANHYDRIDE AS THE ESTERIFING REAGENT, NOT MORE THAN 3 PARTS OF A LOWER FATTY ACID AS THE SOLVENT THEREIN AND A BASIC CATALYST PER PART OF CELLULOSE MATERIAL FOR A SUFFICIENT TIME TO ASSURE AN ALKALI SOLUBLE PRODUCT FOLLOWED BY COOLING THE REACTION MASS TO 50-100*F. AND WITHOUT ADDING DILUENT ADDING TO THE MASS 2-3.5 PARTS OF WATER PER PART OF LOWER FATTY ACID IN AN AMOUNT SUFFICIENT TO CAUSE PERFIPITATION OF THE CELLULOSE DICARBOXYLIC ACID ESTER THEREIN.
Claim 2
Independent Claim
130 words
A METHOD OF PREPARING CELLULOSE DIACARBOXYLIC ACID ESTERS WHICH COMPRISES REACTING UPON A CELLULOSE MATERIAL SELECTED FROM THE GROUP CONSISTING OF THE CELLULOSE ETHERS AND THE LOWER FATTY ACID ESTERS OF CELLULOSE CONTAINING FREE AND ESTERIFIABLE HYDROXYL GROUPS WITH A BATH ESSENTIALLY CONSISTING OF NOT MORE THAN 3 PARTS OF DICARBOXYLIC ACID ANHYDRIDE AS THE ESTERIFING REAGENT, NOT MORE THAN 3 PARTS OF A LOWER FATTY ACID AS THE SOLVENT THEREIN AND A BASIC CATALYST PER PART OF CELLULOSE MATERIAL FOR A SUFFICIENT TIME TO ASSURE AN ALKALI SOLUBLE PRODUCT FOLLOWED BY COOLING THE REACTION MASS TO 50-100*F. AND WITHOUT ADDING DILUENT ADDING TO THE MASS 2-3.5 PARTS OF WATER PER PART OF LOWER FATTY ACID IN AN AMOUNT SUFFICIENT TO CAUSE PERFIPITATION OF THE CELLULOSE DICARBOXYLIC ACID ESTER THEREIN.
References Cited (Backward Citations)
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US2285536A
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US2352261A
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US2555050A
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US2759909A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-09-15 | 1962-03-17 | 1962-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-15 | 1966-03-17 | 1966-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-15 | 1970-03-17 | 1970-09-16 | $7700.00 | Window Closed / Lapsed |