Patent FR463838A successfully refreshed from Google Patents.
US3216481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of phthalic and maleic acid from solutions
Assignee: Badger Co Inc
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Filing: 1962-04-17
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Granted: 1965-11-09
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Expires: 1982-04-17
Abstract
No abstract record available.
Inventors
- 👤 William K Henze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:08
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/43; Y; Y10; Y10S; Y10S159/00; Y10S159/25
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
127 words
PROCESS OF SEPARATING PHTAHLIC ACID AND MALEIC ACID IN SEPARATE PORTIONS FROMAN UNSATURATED AQUEOUS SOLUTION THEREOF, COMPRISING FIRST CONCENTRATING THE SOLUTION BY EVAPORATION AT REDUCED PRESSURE AND RELATAIVELY LOW TEMPERATURE BEYOND THE SATURATION POINT OF THE PHTHALIC ACID CONAINED THEREINTO EFFECT ITS SUBSTANTIAL SEPARATION BY CRYSTALLIZATON FROM THE SAID SOLUTION, SAID EVAPORATION BEING INSUFFICIENT TO SATURATE THE SAID SOLUTION WITH MALEIC ACID, SEPARATING THE PHTHALIC ACID CRYSTALS FROM THE MOTHER LIQUOR AND THEN HEATING THE SOLUTION TO A SUBSTANTIALLY HIGHER TEMPERATREU AND CORRESPONDING PRESSURE, CONTINUING THE EVAPORATION OF THE MOTHER LIQUOR UNTIL THE MALEIC ACID CRYSTALS THEN SEPARATE, AND SEPARATING MEALIC ACID CRYSTALS FROM THE MOTHER LIQUOR, THE LOW TEMPERAURE OF THE FIRST EVAPORATION BEING NOT LESS THAN ABOUT 50*F. AND THE HIGH TEMPERATURE OF THE SECOND
Claim 2
Dependent Claim
127 words
PROCESS OF SEPARATING PHTAHLIC ACID AND MALEIC ACID IN SEPARATE PORTIONS FROMAN UNSATURATED AQUEOUS SOLUTION THEREOF, COMPRISING FIRST CONCENTRATING THE SOLUTION BY EVAPORATION AT REDUCED PRESSURE AND RELATAIVELY LOW TEMPERATURE BEYOND THE SATURATION POINT OF THE PHTHALIC ACID CONAINED THEREINTO EFFECT ITS SUBSTANTIAL SEPARATION BY CRYSTALLIZATON FROM THE SAID SOLUTION, SAID EVAPORATION BEING INSUFFICIENT TO SATURATE THE SAID SOLUTION WITH MALEIC ACID, SEPARATING THE PHTHALIC ACID CRYSTALS FROM THE MOTHER LIQUOR AND THEN HEATING THE SOLUTION TO A SUBSTANTIALLY HIGHER TEMPERATREU AND CORRESPONDING PRESSURE, CONTINUING THE EVAPORATION OF THE MOTHER LIQUOR UNTIL THE MALEIC ACID CRYSTALS THEN SEPARATE, AND SEPARATING MEALIC ACID CRYSTALS FROM THE MOTHER LIQUOR, THE LOW TEMPERAURE OF THE FIRST EVAPORATION BEING NOT LESS THAN ABOUT 50*F. AND THE HIGH TEMPERATURE OF THE SECOND
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-08 | 1969-05-10 | 1969-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-08 | 1973-05-10 | 1973-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-08 | 1977-05-10 | 1977-11-09 | $7700.00 | Window Closed / Lapsed |