US2789974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing tanning agents from black liquor lignin
Assignee: SVENSKA CELLULOSAFORENINGENS C
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Filing: 1955-06-13
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Granted: 1957-04-23
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Expires: 1975-06-13
Abstract
No abstract record available.
Inventors
- 👤 Hagglund Erik Karl Mauritz
- 👤 Hallstrom Lars Eric Georg
- 👤 Richtzenhain Hermann Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:52
CPC Classifications
C; C14; C14C; C14C3/00; C14C3/02; C14C3/08; C14C3/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
133 words
IN THE MANUFACTURE OF WATER-SOLUBLE PRODUCTS POSSESSING TANNING PROPERTIES FROM BLACK LIQUOR LIGNIN, THE PROCESS WHICH COMPRISES FRACTIONALLY PRECIPITATING LIGNIN FROM BLACK LIQUOR BY INTRODUCING AN ACID THEREIN AT DECREASING PH-VALUES UNTIL AT LEAST AN AMOUNT OF LIGNIN CORRESPONDING TO ABOUT 30% OF THE METHOXYL CONTENT OF THE LIQUOR IS PRECIPITATED, SAID LIGNIN FRACTION CONTAINING THE MOST HIGH-MOLECULAR LIGNIN OF THE LIQUOR, SEPARATING THE PRECIPITATE THUS FORMED, CONTINUING INTRODUCTION OF ACID INTO THE REMAINING LIQUOR AT STILL LOWER PHVALUES, WHEREBY MORE LOW-MOLECULAR LIGNIN IS PRECIPITATED, ISOLATING THE LIGNIN FRACTION THUS PRECIPITATED, SULPHONATING SAID ISOLATED LIGNIN FRACTION CONTAINING THE LOWMOLECULAR LIGNIN BY SUBJECTING IF TO THE ACTION OF A SULPHONATING AGENT, SELECTED FROM THE CLASS CONSISTING OF SULPHUROUS ACID AND WATER-SOLUBLE SALTS OF SULPHUROUS ACID, AND THEN RECOVERING THE RESULTING WATER-SOLUBLE SULPHONATED LIGNIN PRODUCT.
Claim 2
Dependent Claim
133 words
IN THE MANUFACTURE OF WATER-SOLUBLE PRODUCTS POSSESSING TANNING PROPERTIES FROM BLACK LIQUOR LIGNIN, THE PROCESS WHICH COMPRISES FRACTIONALLY PRECIPITATING LIGNIN FROM BLACK LIQUOR BY INTRODUCING AN ACID THEREIN AT DECREASING PH-VALUES UNTIL AT LEAST AN AMOUNT OF LIGNIN CORRESPONDING TO ABOUT 30% OF THE METHOXYL CONTENT OF THE LIQUOR IS PRECIPITATED, SAID LIGNIN FRACTION CONTAINING THE MOST HIGH-MOLECULAR LIGNIN OF THE LIQUOR, SEPARATING THE PRECIPITATE THUS FORMED, CONTINUING INTRODUCTION OF ACID INTO THE REMAINING LIQUOR AT STILL LOWER PHVALUES, WHEREBY MORE LOW-MOLECULAR LIGNIN IS PRECIPITATED, ISOLATING THE LIGNIN FRACTION THUS PRECIPITATED, SULPHONATING SAID ISOLATED LIGNIN FRACTION CONTAINING THE LOWMOLECULAR LIGNIN BY SUBJECTING IF TO THE ACTION OF A SULPHONATING AGENT, SELECTED FROM THE CLASS CONSISTING OF SULPHUROUS ACID AND WATER-SOLUBLE SALTS OF SULPHUROUS ACID, AND THEN RECOVERING THE RESULTING WATER-SOLUBLE SULPHONATED LIGNIN PRODUCT.
References Cited (Backward Citations)
US2680113A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-04-22 | 1960-10-22 | 1961-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-22 | 1964-10-22 | 1965-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-22 | 1968-10-22 | 1969-04-23 | $7700.00 | Window Closed / Lapsed |