Patent US2838473A successfully refreshed from Google Patents.
US2838473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rapid method for producing stable novolaks
Assignee: Dow Chemical Co
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Filing: 1953-09-28
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Granted: 1958-06-10
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Expires: 1973-09-28
Abstract
No abstract record available.
Inventors
- 👤 Alexander M Partansky
- 👤 Jr Mack A King
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:28
CPC Classifications
C; C08; C08G; C08G8/00; C08G8/04; C08G8/08; C08G8/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
148 words
THE RAPID METHOD FOR MAKING A STABLE NOVOLAK FROM PHENOL AND FORMALDEHYDE WHICH COMPRISES SUPPLYING TO A PRESSURE VESSEL A MIXTURE CONSISTING ESSENTIALLY OF (A) PHENOL, (B) FROM 0.5 TO 0.9 MOL OF FORMALDEHYDE PER MOL OF PHENOL, (C) FROM 0.5 TO 2 TIMES AS MUCH WATER AS PHENOL BY WEIGHT AND (D) FROM 0.1 TO 5 PERCENT, BASED ON THE WEIGHT OF PHENOL, OF A STRONG MINERAL ACID, CLOSING THE VESSEL, SUPPLYING HEAT TO THE MIXTURE ONLY UNTIL VIGOROUS EXOTHERMIC REACTION IS FIRST EVIDENCED, MAINTAINING THE MIXTURE IS SAID CLOSED VESSEL UNDER THE VARYING AUTOGENOUS SUPERATMOSPHERIC PRESSURE UNTIL THE TEMPERATURE AND PRESSURE VALUES CEASE RISING AND START TO DECLINE; AND THEN ALLOWING THE CLOSED VESSEL AND THE MIXTURE THEREIN TO COOL BY UNAIDED RADIATION TO A TEMPERATURE BELOW 150*C., AND THEREAFTER COOLING THE MIXTURE INA THE CLOSED VESSEL UNTIL THE PRESSURE IN THE VESSEL IS ATMOSPHERIC PRESSURE.
Claim 2
Dependent Claim
148 words
THE RAPID METHOD FOR MAKING A STABLE NOVOLAK FROM PHENOL AND FORMALDEHYDE WHICH COMPRISES SUPPLYING TO A PRESSURE VESSEL A MIXTURE CONSISTING ESSENTIALLY OF (A) PHENOL, (B) FROM 0.5 TO 0.9 MOL OF FORMALDEHYDE PER MOL OF PHENOL, (C) FROM 0.5 TO 2 TIMES AS MUCH WATER AS PHENOL BY WEIGHT AND (D) FROM 0.1 TO 5 PERCENT, BASED ON THE WEIGHT OF PHENOL, OF A STRONG MINERAL ACID, CLOSING THE VESSEL, SUPPLYING HEAT TO THE MIXTURE ONLY UNTIL VIGOROUS EXOTHERMIC REACTION IS FIRST EVIDENCED, MAINTAINING THE MIXTURE IS SAID CLOSED VESSEL UNDER THE VARYING AUTOGENOUS SUPERATMOSPHERIC PRESSURE UNTIL THE TEMPERATURE AND PRESSURE VALUES CEASE RISING AND START TO DECLINE; AND THEN ALLOWING THE CLOSED VESSEL AND THE MIXTURE THEREIN TO COOL BY UNAIDED RADIATION TO A TEMPERATURE BELOW 150*C., AND THEREAFTER COOLING THE MIXTURE INA THE CLOSED VESSEL UNTIL THE PRESSURE IN THE VESSEL IS ATMOSPHERIC PRESSURE.
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) | 1961-06-09 | 1961-12-09 | 1962-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-09 | 1965-12-09 | 1966-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-09 | 1969-12-09 | 1970-06-10 | $7700.00 | Window Closed / Lapsed |