US2988581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for melting or concentrating to a melt solutions of urea and other organic compounds
Assignee: Stamicarbon BV
•
Filing: 1955-12-02
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Granted: 1961-06-13
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Expires: 1975-12-02
Abstract
No abstract record available.
Inventors
- 👤 Wilhelm P J Van Berkel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:38
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/02; C07C273/14; C07C273/16; B; B01; B01J; B01J6/00; B01J6/005; C05; C05C; C05C9/00; C05C9/005; C07H; C07H1/00; H; H05; H05B; H05B3/00; H05B3/60
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
92 words
IN A PROCESS FOR FORMING A MELT OF A SOLID ORGANIC COMPOUND WHICH, WHEN SOLID, HAS A SPECIFIC RESISTANCE OF AT LEAST ABOUT 10 MILLION OHMS CM. BUT WHICH, WHEN IN A LIQUID STATE, SHOWS A SPECIFIC RESISTANCE NOT OVER ABOUT ONE MILLION OHMS CM., THE IMPROVEMENT COMPRISING GENERATING THE HEAT FOR MAINTAINING THE MELT BY DIRECT PASSAGE OF AN ELECTRIC CURRENT THROUGH A PORTION OF THE COMPOUND IN THE MOLTEN STATE AND ADDING THE BALANCE OF THE COMPOUND IN NON-MOLTEN FORM DURING THE PASSAGE OF ELECTRICITY AND RECOVERING THE MOLTEN PRODUCT.
Claim 2
Dependent Claim
92 words
IN A PROCESS FOR FORMING A MELT OF A SOLID ORGANIC COMPOUND WHICH, WHEN SOLID, HAS A SPECIFIC RESISTANCE OF AT LEAST ABOUT 10 MILLION OHMS CM. BUT WHICH, WHEN IN A LIQUID STATE, SHOWS A SPECIFIC RESISTANCE NOT OVER ABOUT ONE MILLION OHMS CM., THE IMPROVEMENT COMPRISING GENERATING THE HEAT FOR MAINTAINING THE MELT BY DIRECT PASSAGE OF AN ELECTRIC CURRENT THROUGH A PORTION OF THE COMPOUND IN THE MOLTEN STATE AND ADDING THE BALANCE OF THE COMPOUND IN NON-MOLTEN FORM DURING THE PASSAGE OF ELECTRICITY AND RECOVERING THE MOLTEN PRODUCT.
References Cited (Backward Citations)
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US1717308A
Cited
US2300891A
Cited
US2370238A
Cited
US2666127A
Cited
US2749379A
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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) | 1964-06-12 | 1964-12-12 | 1965-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-12 | 1968-12-12 | 1969-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-12 | 1972-12-12 | 1973-06-13 | $7700.00 | Window Closed / Lapsed |