Patent US2640803A successfully refreshed from Google Patents.
US2640803A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of treating high molecular weight hydrocarbons
Assignee: Shell Development Co
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Filing: 1951-07-30
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Granted: 1953-06-02
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Expires: 1971-07-30
Abstract
No abstract record available.
Inventors
- 👤 John C Illman
- 👤 Harry J Sommer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:06
CPC Classifications
C; C10; C10C; C10C3/00; C10C3/02; C10C3/04
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
47 words
THE METHOD OF TREATING AN ASPHALT WHICH COMPRISES BLOWING SAID ASPHALT IN THE PRESENCE OF A MINOR AMOUNT OF A FLUORINATED PHOSPHORIC ACID WITH A GASEOUS STREAM CONTAINING FREE OXYGEN WHILE SAID ASPHALT IS AT AN ELEVATED TEMPERATURE OF THE ORDER OF 400* F. TO 550* F.
References Cited (Backward Citations)
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US2281728A
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US2438318A
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US2409248A
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US2508428A
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US2508431A
Cited
US2508924A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |