US2795579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purification of chitosan by means of the salicylic acid salt thereof
Assignee: Warner Lambert Co LLC
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Filing: 1953-10-09
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Granted: 1957-06-11
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Expires: 1973-10-09
Abstract
No abstract record available.
Inventors
- 👤 Doczi John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:10
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0024; C08B37/0027; C08B37/003
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
62 words
THE METHOD OF RECOVERING PURIFFIED CHITOSAN FROM CRUDE CHITOSAN WHICH COMPRISES FORMING AN AQUEOUS SOLUTION OF AN ACID SALT OF CRUDE CHITOSAN, ADDING AT LEAST TWO EQUIVALENTS OF A SOLUBLE SALICYLATE PER EQUIVALENT OF CHITOSAN TO SAID SOLUTION OF CHITOSAN SALT, SEPARATING THE RESULTING PRECIPITATE OF CHITOSAN SALICYLATE, DECOMPOSING SAID CHITOSAN SALICYLATE WITH A BASE AND SEPARATING THE RESULTING PURIFIED REGENERATED CHITOSAN.
Claim 2
Independent Claim
62 words
THE METHOD OF RECOVERING PURIFFIED CHITOSAN FROM CRUDE CHITOSAN WHICH COMPRISES FORMING AN AQUEOUS SOLUTION OF AN ACID SALT OF CRUDE CHITOSAN, ADDING AT LEAST TWO EQUIVALENTS OF A SOLUBLE SALICYLATE PER EQUIVALENT OF CHITOSAN TO SAID SOLUTION OF CHITOSAN SALT, SEPARATING THE RESULTING PRECIPITATE OF CHITOSAN SALICYLATE, DECOMPOSING SAID CHITOSAN SALICYLATE WITH A BASE AND SEPARATING THE RESULTING PURIFIED REGENERATED CHITOSAN.
Claim 3
Independent Claim
98 words
THE METHOD OF FRACTIONATING CHITOSAN INTO A PLURALITY OF FRACTIONS OF INCREASED HOMOGENEITY WHICH COMPRISES ADDING AT LEAST TWO EQUIVALENTS OF A SOLUBLE SALICYLATE PER EQUIVALENT OF CHITOSAN TO AN AQUEOUS SOLUTION OF AN ACID SALT OF CHITOSAN, WARMING THE RESULTING MIXTURE UNTIL SUBSTANTIALLY CLEAR SOLUTION RESULTS, GRADUALLY COOLING THE SOLUTION TO A SERIES OF PROGRESSIVELY LOWER TEMPERATURE LEVELS, SEPARATING THE FRACTION OF CHITOSAN SALICYLATE WHICH PRECIPITATES AT EACH OF SAID TEMPERATURE LEVELS, SEPARATELY DECOMPOSING EACH OF SAID FRACTIONS OF CHITOSAN SALICYLATE WITH A BASE AND SEPARATING THE RESULTING SERIES OF REGENERATED CHITOSAN FRACTIONS OF VARYING MOLECULAR WEIGHTS.
Claim 4
Independent Claim
98 words
THE METHOD OF FRACTIONATING CHITOSAN INTO A PLURALITY OF FRACTIONS OF INCREASED HOMOGENEITY WHICH COMPRISES ADDING AT LEAST TWO EQUIVALENTS OF A SOLUBLE SALICYLATE PER EQUIVALENT OF CHITOSAN TO AN AQUEOUS SOLUTION OF AN ACID SALT OF CHITOSAN, WARMING THE RESULTING MIXTURE UNTIL SUBSTANTIALLY CLEAR SOLUTION RESULTS, GRADUALLY COOLING THE SOLUTION TO A SERIES OF PROGRESSIVELY LOWER TEMPERATURE LEVELS, SEPARATING THE FRACTION OF CHITOSAN SALICYLATE WHICH PRECIPITATES AT EACH OF SAID TEMPERATURE LEVELS, SEPARATELY DECOMPOSING EACH OF SAID FRACTIONS OF CHITOSAN SALICYLATE WITH A BASE AND SEPARATING THE RESULTING SERIES OF REGENERATED CHITOSAN FRACTIONS OF VARYING MOLECULAR WEIGHTS.
References Cited (Backward Citations)
US2040879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-06-10 | 1960-12-10 | 1961-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-06-10 | 1964-12-10 | 1965-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-06-10 | 1968-12-10 | 1969-06-11 | $7700.00 | Window Closed / Lapsed |