Patent US2631144A successfully refreshed from Google Patents.
US2631144A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Activation of cellulose
Assignee: EIDP Inc
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Filing: 1950-10-23
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Granted: 1953-03-10
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Expires: 1970-10-23
Abstract
No abstract record available.
Inventors
- 👤 Jr Lejaren Arthur Hiller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:18
CPC Classifications
C; C08; C08B; C08B1/00; C08B1/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
36 words
IN THE ESTERIFLCATION OF CELLULOSE WITH ACID ANHYDRIDES IN THE PRESENCE OF A BASIC CATALYST, THE IMPROVEMENT WHICH COMPRISES HEATING THE CELLULOSE PRIOR TO ESTERIFICATION AT A TEMPERATURE OF ABOUT 75* C. TO ABOUT 125* C.
Claim 2
Dependent Claim
36 words
IN THE ESTERIFLCATION OF CELLULOSE WITH ACID ANHYDRIDES IN THE PRESENCE OF A BASIC CATALYST, THE IMPROVEMENT WHICH COMPRISES HEATING THE CELLULOSE PRIOR TO ESTERIFICATION AT A TEMPERATURE OF ABOUT 75* C. TO ABOUT 125* C.
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) | 1956-03-09 | 1956-09-08 | 1957-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-03-09 | 1960-09-08 | 1961-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-03-09 | 1964-09-08 | 1965-03-10 | $7700.00 | Window Closed / Lapsed |