US2523384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ripening process
Assignee: Celanese Corp
•
Filing: 1946-07-17
•
Granted: 1950-09-26
•
Expires: 1966-07-17
Abstract
No abstract record available.
Inventors
- 👤 Mervin E Martin
- 👤 William E Kight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 03:02
CPC Classifications
C; C08; C08B; C08B3/00; C08B3/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
121 words
IN A PROCESS FOR THE PRODUCTION OF ORGANIC ACID ESTERS OF CELLULOSE OF IMPROVED CHARACTERISTICS WHEREIN CELLULOSE IS ESTERIFIED WITH A LOWER ALIPHATIC ACID ANHYDRIDE EMPLOYING A LOWER ALIPHATIC ACID AS SOLVENT AND AN INORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF SULFURIC ACID AND PHOSPHORIC ACID AS CATALYST, THE STEPS WHICH COMPRISE ADDING TO THE PRIMARY CELLULOSE ESTER SOLUTION, OBTAINED ON COMPLETION OF ESTERIFICATION, WATER FOR RIPENING AND A NEUTRALIZING AGENT IN AN AMOUNT AT LEAST SUFFICIENT TO NEUTRALIZE COMPLETELY ALL THE INORGANIC ACID EMPLOYED AS CATALYST, ADDING AMMOMIUM BISULFATE TO THE PRIMARY CELLULOSE ESTER SOLUTION, AND RIPENING THE PRIMARY CELLULOSE ESTER TO A SECONDARY CELLULOSE ESTER AT AN ELEVATED TEMPERATURE, SAID AMMONIUM BISULFATE ACTING AI AID THE RIPENING REACTION.
Claim 2
Dependent Claim
121 words
IN A PROCESS FOR THE PRODUCTION OF ORGANIC ACID ESTERS OF CELLULOSE OF IMPROVED CHARACTERISTICS WHEREIN CELLULOSE IS ESTERIFIED WITH A LOWER ALIPHATIC ACID ANHYDRIDE EMPLOYING A LOWER ALIPHATIC ACID AS SOLVENT AND AN INORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF SULFURIC ACID AND PHOSPHORIC ACID AS CATALYST, THE STEPS WHICH COMPRISE ADDING TO THE PRIMARY CELLULOSE ESTER SOLUTION, OBTAINED ON COMPLETION OF ESTERIFICATION, WATER FOR RIPENING AND A NEUTRALIZING AGENT IN AN AMOUNT AT LEAST SUFFICIENT TO NEUTRALIZE COMPLETELY ALL THE INORGANIC ACID EMPLOYED AS CATALYST, ADDING AMMOMIUM BISULFATE TO THE PRIMARY CELLULOSE ESTER SOLUTION, AND RIPENING THE PRIMARY CELLULOSE ESTER TO A SECONDARY CELLULOSE ESTER AT AN ELEVATED TEMPERATURE, SAID AMMONIUM BISULFATE ACTING AI AID THE RIPENING REACTION.
References Cited (Backward Citations)
US1723614A
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US2099753A
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US2095326A
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US2165850A
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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) | 1953-09-25 | 1954-03-27 | 1954-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-09-25 | 1958-03-27 | 1958-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-09-25 | 1962-03-27 | 1962-09-26 | $7700.00 | Window Closed / Lapsed |