US2638415A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of cellulose
Assignee: Celanese Corp
•
Filing: 1948-12-27
•
Granted: 1953-05-12
•
Expires: 1968-12-27
Abstract
No abstract record available.
Inventors
- 👤 Jones John Edward
- 👤 Stott Reginald Richard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:14
CPC Classifications
D; D21; D21C; D21C1/00; D21C1/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
89 words
PROCESS FOR THE PRODUCTION OF CELLULOSE FROM RAW LIGNO-CELLULOSIC MATERIAL, WHICH COMPRISES IMPREGNATING THE MATERIAL WITH A 2 TO 5% AQUEOUS SOLUTION OF A CAUSTIC ALKALI, LOWERING THE TEMPERATURE OF THE IMPREGNATED MATERIAL TO A LEVEL AT WHICH ALL THE WATER CONTAINED THEREIN IS FROZEN, KEEPING THE IMPREGNATED MATERIAL IN THIS CONDITION FOR 1 TO 5 HOURS, RAISING THE TEMPERATURE SO AS TO MELT ALL THE ICE FORMED, REMOVING AT LEAST THE GREATER PART OF THE ALKALI SOLUTION FROM THE MATERIAL AND SUBJECTING THE MATERIAL TO A DELIGNIFYING TREATMENT.
Claim 2
Dependent Claim
89 words
PROCESS FOR THE PRODUCTION OF CELLULOSE FROM RAW LIGNO-CELLULOSIC MATERIAL, WHICH COMPRISES IMPREGNATING THE MATERIAL WITH A 2 TO 5% AQUEOUS SOLUTION OF A CAUSTIC ALKALI, LOWERING THE TEMPERATURE OF THE IMPREGNATED MATERIAL TO A LEVEL AT WHICH ALL THE WATER CONTAINED THEREIN IS FROZEN, KEEPING THE IMPREGNATED MATERIAL IN THIS CONDITION FOR 1 TO 5 HOURS, RAISING THE TEMPERATURE SO AS TO MELT ALL THE ICE FORMED, REMOVING AT LEAST THE GREATER PART OF THE ALKALI SOLUTION FROM THE MATERIAL AND SUBJECTING THE MATERIAL TO A DELIGNIFYING TREATMENT.
References Cited (Backward Citations)
US1602253A
Cited
GB267226A
Cited
US1755657A
Cited
GB301088A
Cited
GB317046A
Cited
US2061616A
Cited
US2138283A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-05-11 | 1956-11-10 | 1957-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-11 | 1960-11-10 | 1961-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-11 | 1964-11-10 | 1965-05-12 | $7700.00 | Window Closed / Lapsed |