Patent US2775585A successfully refreshed from Google Patents.
US2775585A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ripening cellulose esters in solution
Assignee: Acordis UK Ltd
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Filing: 1953-06-05
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Granted: 1956-12-25
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Expires: 1973-06-05
Abstract
No abstract record available.
Inventors
- 👤 Bates Harold
- 👤 Fisher James Wotherspoon
- 👤 Smith John Richard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:31
CPC Classifications
C; C08; C08B; C08B3/00; C08B3/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
164 words
A PROCESS FOR RIPENING CELLULOSE ESTERS OF CARBOXYLIC ACIDS CONTAINING 2 TO 4 CARBON ATOMS IN THE MOLECULE MADE BY ESTERIFYING CELLULOSE WITH THE ANHYDRIDE OF AT LEAST ONE SUCH ACID IN THE PRESENCE OF MORE THAN 350% ON THE WEIGHT OF THE CELLULOSE OF A SOLVENT SELECTED FROM THE GROUP WHICH CONSISTS OF METHYLENE CHLORIDE AND ETHYLENE CHLORIDE AND OF SULPHURIC ACID AS CATALYST, WHICH COMPRISES ADDING WATER TO THE PRIMARY ESTERIFICATION SOLUTION IN AMOUNT SUFFICIENT BOTH TO HYDROLYSE RESIDUAL ACID ANHYDRIDE AND TO PROVIDE WATER FOR THE RIPENING REACTION, NEUTRALISING SUBSTANTIALLY ALL THE SULPHURIC ACID IN THE SOLUTION, REMOVING FROM SOLUTION BY DISTILLATION A SUBSTANTIAL PROPORTION OF ITS CONTENT OF THE SOLVENT BUT RETAINING AN AMOUNT OF SOLVENT WHICH FOR METHYLENE CHLORIDE IS AT LEAST 30% AND FOR ETHYLENE CHLORIDE IS AT LEAST 50% OF THE WEIGHT OF THE CELLULOSE AND THEN HEATING THE SOLUTION TO A TEMPERATURE BETWEEN 100* AND 220* C. UNTIL THE DESIRED DEGREE OF RIPENING HAS TAKEN PLACE.
Claim 2
Dependent Claim
164 words
A PROCESS FOR RIPENING CELLULOSE ESTERS OF CARBOXYLIC ACIDS CONTAINING 2 TO 4 CARBON ATOMS IN THE MOLECULE MADE BY ESTERIFYING CELLULOSE WITH THE ANHYDRIDE OF AT LEAST ONE SUCH ACID IN THE PRESENCE OF MORE THAN 350% ON THE WEIGHT OF THE CELLULOSE OF A SOLVENT SELECTED FROM THE GROUP WHICH CONSISTS OF METHYLENE CHLORIDE AND ETHYLENE CHLORIDE AND OF SULPHURIC ACID AS CATALYST, WHICH COMPRISES ADDING WATER TO THE PRIMARY ESTERIFICATION SOLUTION IN AMOUNT SUFFICIENT BOTH TO HYDROLYSE RESIDUAL ACID ANHYDRIDE AND TO PROVIDE WATER FOR THE RIPENING REACTION, NEUTRALISING SUBSTANTIALLY ALL THE SULPHURIC ACID IN THE SOLUTION, REMOVING FROM SOLUTION BY DISTILLATION A SUBSTANTIAL PROPORTION OF ITS CONTENT OF THE SOLVENT BUT RETAINING AN AMOUNT OF SOLVENT WHICH FOR METHYLENE CHLORIDE IS AT LEAST 30% AND FOR ETHYLENE CHLORIDE IS AT LEAST 50% OF THE WEIGHT OF THE CELLULOSE AND THEN HEATING THE SOLUTION TO A TEMPERATURE BETWEEN 100* AND 220* C. UNTIL THE DESIRED DEGREE OF RIPENING HAS TAKEN PLACE.
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) | 1959-12-25 | 1960-06-25 | 1960-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-12-25 | 1964-06-25 | 1964-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-12-25 | 1968-06-25 | 1968-12-25 | $7700.00 | Window Closed / Lapsed |