US2740776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Organic acid esters of cellulose
Assignee: Celanese Corp
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Filing: 1952-01-10
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Granted: 1956-04-03
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Expires: 1972-01-10
Abstract
No abstract record available.
Inventors
- 👤 Leonard J Rosen
- 👤 Adam J Pikor
- 👤 Blanche B White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:31
CPC Classifications
C; C08; C08B; C08B3/00; C08B3/22; C08B3/26; C08B3/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
164 words
IN A PROCESS FOR THE PRODUCTION OF ORGANIC ACID ESTERS OF CELLULOSE WHEREIN A CELLULOSIC MATERIAL IS ESTERIFIED IN THE PRESENCE OF AN ACID ESTERIFICATION CATALYST AND A LOWER ALIPHATIC ACID SOLVENT FOR THE ORGANIC ACID ESTER OF CELLULOSE BEING FORMED WHEREBY AN ACID DOPE IS OBTAINED, THE STEPS WHICH COMPRISE NEUTRALIZING AT LEAST A PART OF THE ACID ESTERIFICATION CATALYST WITH AN ALKALINE MATERIAL, SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM ACETATE, MAGNESIUM PROPIONATE AND MAGNESIUM BUTYRATE, WHICH WILL REACT WITH THE CATALYT TO PRODUCE A SALT DIFFICULTLY SOLUBLE IN THE ACID DOPE, FILTERING THE ACID DOPE WHEREBY ALL OF THE SALT IS REMOVED THEREFROM, AND MIXING THE SALT-FREE ACID DOPE WITH AN AQUEOUS PRECIPITATING MEDIUM, CONTAINING THEREIN A DISSOLVED SALT, SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM SULFATE, SODIUM SULFATE, MAGNESIUM ACETATE, CALCIUM ACETATE AND MAGNESIUM NITRATE, WHEREBY THE ORGANIC ACID ESTER OF CELLULOSE IS PRECIPITATED FROM THE ACID DOPE IN THE FORM OF A FIBROUS FLAKE HAVING A HIGH BULK DENSITY.
Claim 2
Dependent Claim
164 words
IN A PROCESS FOR THE PRODUCTION OF ORGANIC ACID ESTERS OF CELLULOSE WHEREIN A CELLULOSIC MATERIAL IS ESTERIFIED IN THE PRESENCE OF AN ACID ESTERIFICATION CATALYST AND A LOWER ALIPHATIC ACID SOLVENT FOR THE ORGANIC ACID ESTER OF CELLULOSE BEING FORMED WHEREBY AN ACID DOPE IS OBTAINED, THE STEPS WHICH COMPRISE NEUTRALIZING AT LEAST A PART OF THE ACID ESTERIFICATION CATALYST WITH AN ALKALINE MATERIAL, SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM ACETATE, MAGNESIUM PROPIONATE AND MAGNESIUM BUTYRATE, WHICH WILL REACT WITH THE CATALYT TO PRODUCE A SALT DIFFICULTLY SOLUBLE IN THE ACID DOPE, FILTERING THE ACID DOPE WHEREBY ALL OF THE SALT IS REMOVED THEREFROM, AND MIXING THE SALT-FREE ACID DOPE WITH AN AQUEOUS PRECIPITATING MEDIUM, CONTAINING THEREIN A DISSOLVED SALT, SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM SULFATE, SODIUM SULFATE, MAGNESIUM ACETATE, CALCIUM ACETATE AND MAGNESIUM NITRATE, WHEREBY THE ORGANIC ACID ESTER OF CELLULOSE IS PRECIPITATED FROM THE ACID DOPE IN THE FORM OF A FIBROUS FLAKE HAVING A HIGH BULK DENSITY.
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) | 1959-04-03 | 1959-10-03 | 1960-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-04-03 | 1963-10-03 | 1964-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-04-03 | 1967-10-03 | 1968-04-03 | $7700.00 | Window Closed / Lapsed |