Patent US2882965A successfully refreshed from Google Patents.
US2882965A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High viscosity, high percentage alpha cellulose from sulfite pulp
Assignee: Columbia Cellulose Co Ltd
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Filing: 1955-02-23
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Granted: 1959-04-21
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Expires: 1975-02-23
Abstract
No abstract record available.
Inventors
- 👤 Wayman Morris
- 👤 William A Kraske
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:36
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/08; D21C9/083
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
A MULTI-STAGE PROCESS FOR THE PURIFICATON OF SULFITE PULP WHICH COMPRISES SLURRYING THE PULP WITH A FIRST CAUSTIC SODA SOLUTION HAVING A CAUSTIC CONCENTRATION OF BETWEEN ABOUT 1 AND 13% BY WEIGHT BASED ON THE WEIGHT OF THE PULP, AT A TEMPERATURE BETWEEN ABOUT 90 AND 170*C. AND AT A CONSISTENCY OF BETWEEN ABOUT 5 AND 20% BY WEIGHT FOR A PERIOD OF BETWEEN ABOUT 8 AND 240 MINUTES, AND, AS THE NEXT IMMEDIATE CHEMICAL TREATMENT OF THE PULP, SLURRYING THE PULP WITH A SECOND CAUSTIC SODA SOLUTION HAVING A CAUSTIC CONCENTRATON OF BETWEEN ABOUT 40 AND 220 GRAMS PER LITER, AT A TEMPERATURE OF BETWEEN ABOUT 5 AND 50*C., AND AT A CONSISTENCY OF BETWEEN ABOUT 2 AND 18% BY WEIGHT, FOR A PERIOD OF BETWEEN ABOUT 5 AND 120 MINUTES.
Claim 2
Dependent Claim
132 words
A MULTI-STAGE PROCESS FOR THE PURIFICATON OF SULFITE PULP WHICH COMPRISES SLURRYING THE PULP WITH A FIRST CAUSTIC SODA SOLUTION HAVING A CAUSTIC CONCENTRATION OF BETWEEN ABOUT 1 AND 13% BY WEIGHT BASED ON THE WEIGHT OF THE PULP, AT A TEMPERATURE BETWEEN ABOUT 90 AND 170*C. AND AT A CONSISTENCY OF BETWEEN ABOUT 5 AND 20% BY WEIGHT FOR A PERIOD OF BETWEEN ABOUT 8 AND 240 MINUTES, AND, AS THE NEXT IMMEDIATE CHEMICAL TREATMENT OF THE PULP, SLURRYING THE PULP WITH A SECOND CAUSTIC SODA SOLUTION HAVING A CAUSTIC CONCENTRATON OF BETWEEN ABOUT 40 AND 220 GRAMS PER LITER, AT A TEMPERATURE OF BETWEEN ABOUT 5 AND 50*C., AND AT A CONSISTENCY OF BETWEEN ABOUT 2 AND 18% BY WEIGHT, FOR A PERIOD OF BETWEEN ABOUT 5 AND 120 MINUTES.
References Cited (Backward Citations)
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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) | 1962-04-20 | 1962-10-20 | 1963-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-20 | 1966-10-20 | 1967-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-20 | 1970-10-20 | 1971-04-21 | $7700.00 | Window Closed / Lapsed |