US2676143A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Formaldehyde concentration process
Assignee: EIDP Inc
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Filing: 1949-11-22
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Granted: 1954-04-20
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Expires: 1969-11-22
Abstract
No abstract record available.
Inventors
- 👤 Donald D Lee
- 👤 Herbert S Lecky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:59
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/78; C07C45/81
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
103 words
IN A PROCESS FOR DEHYDRATING FORMALDEHYDE THE STEPS WHICH COMPRISE FLASH EVAPORATING A SOLUTION OF FORMALDEHYDE CONTAINING ABOUT 60% FORMALDEHYDE AT A PRESSURE BELOW 300 MM. OF MERCURY, PASSING THE DISTILLATE TO PRESSURE DISTILLATION AND THE BOTTOMS TO VACUUM CONCENTRATION UNDER A PRESSURE OF LESS THAN 600 MM. OF MERCURY, DURING VACUUM CONCENTRATION ADDING METHANOL, PASSING THE BOTTOMS TO CONCENTRATED FORMALDEHYDE STORAGE AND DISTILLATE TO A METHANOL STRIPPING OPERATION, DURING PRESSURE DITILLATION PASSING THE DILTILLATE TO THE METHANOL STRIPPING OPERATION AND THE BOTTOMS TO SEWER, DURING THE METHANOL STRIPPING OPERATION PASSING THE DISTILLATE TO VACUUM CONCENTRATION AND THE BOTTOMS TO VACUUM FLASH EVAPORATION.
Claim 2
Dependent Claim
103 words
IN A PROCESS FOR DEHYDRATING FORMALDEHYDE THE STEPS WHICH COMPRISE FLASH EVAPORATING A SOLUTION OF FORMALDEHYDE CONTAINING ABOUT 60% FORMALDEHYDE AT A PRESSURE BELOW 300 MM. OF MERCURY, PASSING THE DISTILLATE TO PRESSURE DISTILLATION AND THE BOTTOMS TO VACUUM CONCENTRATION UNDER A PRESSURE OF LESS THAN 600 MM. OF MERCURY, DURING VACUUM CONCENTRATION ADDING METHANOL, PASSING THE BOTTOMS TO CONCENTRATED FORMALDEHYDE STORAGE AND DISTILLATE TO A METHANOL STRIPPING OPERATION, DURING PRESSURE DITILLATION PASSING THE DILTILLATE TO THE METHANOL STRIPPING OPERATION AND THE BOTTOMS TO SEWER, DURING THE METHANOL STRIPPING OPERATION PASSING THE DISTILLATE TO VACUUM CONCENTRATION AND THE BOTTOMS TO VACUUM FLASH EVAPORATION.
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) | 1957-04-19 | 1957-10-19 | 1958-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-04-19 | 1961-10-19 | 1962-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-04-19 | 1965-10-19 | 1966-04-20 | $7700.00 | Window Closed / Lapsed |