US2837468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of polyhydric alcohols
Assignee: Trojan Powder Co
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Filing: 1955-12-23
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Granted: 1958-06-03
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Expires: 1975-12-23
Abstract
No abstract record available.
Inventors
- 👤 Robert J Ruhf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:31
CPC Classifications
C; C07; C07C; C07C43/00; C07C43/02; C07C43/03; C07C43/04; C07C43/13
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
120 words
IN PURIFYING POLYOLS OF THE GENERAL TYPE FORMULA R4-NC(CH2OH)N WHEREIN R REPRESENTS MONOVALENT UNITS CONTAINING EACH NOT MORE THAN 4 CARBON ATOMS SELECTED FROM THE GROUP CONSISTING OF ALKYL AND ALKOXY GROUPS AND N IS AN INTEGER WITHIN THE RANGE 2-4, THE PROCESS WHICH COMPRISES INTRODUCING INTO THE POLYOL AN ACID IN ANY AMOUNT REQUIRED TO ESTABLISH THE PH OF THE RESULTING MIXTURE APPROXIMATELY WITHIN THE RANGE 5-6.7 DURING THE DISTILLATION OF THE POLYOL, SUBJECTING THE MIXTURE IN SUBSTANTIALLY ANHYDROUS CONDITION TO DISTILLATION AT A TEMPERATURE OF 136*-206*C. AND AT A PRESSURE CORRESPONDING TO NOT MORE THAN ABOUT 50 MM. OF MERCURY, AND MAINTAINING THE PH IN THE SAID MIXTURE DURING THE DISTILLATION OF THE POLYOL WITHIN THE SAID RANGE.
Claim 2
Dependent Claim
120 words
IN PURIFYING POLYOLS OF THE GENERAL TYPE FORMULA R4-NC(CH2OH)N WHEREIN R REPRESENTS MONOVALENT UNITS CONTAINING EACH NOT MORE THAN 4 CARBON ATOMS SELECTED FROM THE GROUP CONSISTING OF ALKYL AND ALKOXY GROUPS AND N IS AN INTEGER WITHIN THE RANGE 2-4, THE PROCESS WHICH COMPRISES INTRODUCING INTO THE POLYOL AN ACID IN ANY AMOUNT REQUIRED TO ESTABLISH THE PH OF THE RESULTING MIXTURE APPROXIMATELY WITHIN THE RANGE 5-6.7 DURING THE DISTILLATION OF THE POLYOL, SUBJECTING THE MIXTURE IN SUBSTANTIALLY ANHYDROUS CONDITION TO DISTILLATION AT A TEMPERATURE OF 136*-206*C. AND AT A PRESSURE CORRESPONDING TO NOT MORE THAN ABOUT 50 MM. OF MERCURY, AND MAINTAINING THE PH IN THE SAID MIXTURE DURING THE DISTILLATION OF THE POLYOL WITHIN THE SAID RANGE.
References Cited (Backward Citations)
US2333696A
Cited
US2381855A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-02 | 1961-12-02 | 1962-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-02 | 1965-12-02 | 1966-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-02 | 1969-12-02 | 1970-06-03 | $7700.00 | Window Closed / Lapsed |