US3124503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Formaldehyde pulping
Assignee: —
•
Filing: —
•
Granted: 1964-03-10
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Expires: 1981-03-10
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:52
CPC Classifications
D; D21; D21C; D21C3/00; D21C3/003
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
146 words
A PROCESS FOR PRODUCING PULP FROM SUBDIVIDED HARDWOOD MATERIAL WHEREIN SAID MATERIAL IS DIGESTED AT A TEMPERATURE OF ABOUT 130*C. TO ABOUT 200*C. FOR A PERIOD OF ABOUT 5 TO ABOUT 300 MINUTES IN THE PRESENCE OF ABOUT TWO TO ABOUT TEN TIMES ITS BONE DRY WEIGHT OF AN AQUEOUS SOLUTION CONTAINING ABOUT 25% TO ABOUT 50% OF FORMALDHYDE, THEREBY SUBSTANTIALLY COMPLETELY RELEASING THE LIGNIN IN SAID MATERIAL FROM ITS BOUND CONDITION WITH THE CELLULOSIC MATERIAL AND CONVERGING ANY REMAINING LIGNIN TO A CONDITION WHEREIN IT IS READILY EXTRACTABLE WITH A DILUTE AQUEOUS SOLUTION OF SODIUM HYDROXIDE, THE FINAL PH OF THE DIGESTING SOLUTION BEING FROM ABOUT 1 TO ABOUT 11, RECOVERING FROM THE DIGESTION SOLUTION A PULP HAVING A SUBSTANTIALLY REDUCED LIGNIN AND PENTOSAN CONTENT AS COMPARED WITH THE UNDIGESTED LIGNOCELLULOSIC MATERIAL, AND EXTRACTING THE RECOVERED PULP WITH A DILUTE AQUEOUS SOLUTION OF SODIUM HYDROXIDE.
Claim 2
Dependent Claim
146 words
A PROCESS FOR PRODUCING PULP FROM SUBDIVIDED HARDWOOD MATERIAL WHEREIN SAID MATERIAL IS DIGESTED AT A TEMPERATURE OF ABOUT 130*C. TO ABOUT 200*C. FOR A PERIOD OF ABOUT 5 TO ABOUT 300 MINUTES IN THE PRESENCE OF ABOUT TWO TO ABOUT TEN TIMES ITS BONE DRY WEIGHT OF AN AQUEOUS SOLUTION CONTAINING ABOUT 25% TO ABOUT 50% OF FORMALDHYDE, THEREBY SUBSTANTIALLY COMPLETELY RELEASING THE LIGNIN IN SAID MATERIAL FROM ITS BOUND CONDITION WITH THE CELLULOSIC MATERIAL AND CONVERGING ANY REMAINING LIGNIN TO A CONDITION WHEREIN IT IS READILY EXTRACTABLE WITH A DILUTE AQUEOUS SOLUTION OF SODIUM HYDROXIDE, THE FINAL PH OF THE DIGESTING SOLUTION BEING FROM ABOUT 1 TO ABOUT 11, RECOVERING FROM THE DIGESTION SOLUTION A PULP HAVING A SUBSTANTIALLY REDUCED LIGNIN AND PENTOSAN CONTENT AS COMPARED WITH THE UNDIGESTED LIGNOCELLULOSIC MATERIAL, AND EXTRACTING THE RECOVERED PULP WITH A DILUTE AQUEOUS SOLUTION OF SODIUM HYDROXIDE.
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) | 1967-03-10 | 1967-09-09 | 1968-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-03-10 | 1971-09-09 | 1972-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-03-10 | 1975-09-09 | 1976-03-10 | $7700.00 | Window Closed / Lapsed |