Patent US2680738A successfully refreshed from Google Patents.
US2680738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of alkali cellulose
Assignee: Hercules Powder Co
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Filing: 1952-04-11
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Granted: 1954-06-08
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Expires: 1972-04-11
Abstract
No abstract record available.
Inventors
- 👤 Kenneth C Laughlin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:38
CPC Classifications
C; C08; C08B; C08B1/00; C08B1/08; C08B11/00; C08B11/02; C08B11/04; C08B11/10; C08B11/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
135 words
A PROCESS FOR PREPARING UNIFORMLY SUBSTITUTED ALKALI CELLULOSE WHICH COMPRISES FORMING A SLURRY OF CELLULOSE IN A MEDIUM OF THE GROUP CONSISTING OF THE ALIPHATIC ALCOHOLS HAVING FROM 2 TO 5 CARBON ATOMS PER MOLECULE, DIOXANE, TETRAHYDROFURAN, AND MIXTURE THEREOF, SIMULTANEOUSLY INTRODUCING RESULTING SLURRY AND AN AQUEOUS SOLUTION OF CAUSTIC ALKALI TO A REACTION VESSEL AT A RATE SUCH THAT THE RATIO OF CAUSTIC ALKALI TO CELLULOSE IS MAINTAINED WITHIN THE RANGE OF 0.2 TO 1.8 PARTS OF CAUSTIC ALIKLI PER PART OF CELLULOSE, AND THE RATIO OF WATER TO CELLULOSE IS MAINTAINED WITHIN THE RANGE OF 0.5 TO 8 PARTS OF WATER PER PART OF CELLULOSE, AND CONTACTING SAID CAUSTIC ALKALI AND CELLULOSE WHILE MAINTAINING SAID RATIOS FOR A PERIOD OF 3 TO 15 MINUTES AT A TEMPERATURE NOT IN EXCESS OF 30* C.
Claim 2
Dependent Claim
135 words
A PROCESS FOR PREPARING UNIFORMLY SUBSTITUTED ALKALI CELLULOSE WHICH COMPRISES FORMING A SLURRY OF CELLULOSE IN A MEDIUM OF THE GROUP CONSISTING OF THE ALIPHATIC ALCOHOLS HAVING FROM 2 TO 5 CARBON ATOMS PER MOLECULE, DIOXANE, TETRAHYDROFURAN, AND MIXTURE THEREOF, SIMULTANEOUSLY INTRODUCING RESULTING SLURRY AND AN AQUEOUS SOLUTION OF CAUSTIC ALKALI TO A REACTION VESSEL AT A RATE SUCH THAT THE RATIO OF CAUSTIC ALKALI TO CELLULOSE IS MAINTAINED WITHIN THE RANGE OF 0.2 TO 1.8 PARTS OF CAUSTIC ALIKLI PER PART OF CELLULOSE, AND THE RATIO OF WATER TO CELLULOSE IS MAINTAINED WITHIN THE RANGE OF 0.5 TO 8 PARTS OF WATER PER PART OF CELLULOSE, AND CONTACTING SAID CAUSTIC ALKALI AND CELLULOSE WHILE MAINTAINING SAID RATIOS FOR A PERIOD OF 3 TO 15 MINUTES AT A TEMPERATURE NOT IN EXCESS OF 30* C.
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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) | 1957-06-07 | 1957-12-07 | 1958-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-06-07 | 1961-12-07 | 1962-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-06-07 | 1965-12-07 | 1966-06-08 | $7700.00 | Window Closed / Lapsed |