US3730877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of base oils for the production of lubricating oil
Assignee: Shell USA Inc
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Filing: 1968-12-05
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Granted: 1973-05-01
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Expires: 1988-12-05
Abstract
Abstract HIGH VISCOSITY INDEX LUBRICATING BASE OILS ARE PREPARED BY TREATING PARAFFINIC-NAPHTHENIC OILS HAVING A LOW AROMATIC CONTENT AND A HIGH CONTENT OF NAPHTHENES WITH CONDENSED RINGS WITH HYDROGEN IN THE PRESENCE OF PLATINUM ON ALUMINA CATALYST CONTAINING NOT MORE THAN 4% WT. OF AN ALKALI OR ALKALINE EARTH METAL AT A HYDROGEN PARTIAL PRESSURE ABOVE 10 KG./CM.2 AND A TEMPERATURE OF AT LEAST 345*C.
Inventors
- 👤 W Quik
- 👤 Weeren P Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:28
CPC Classifications
C; C10; C10G; C10G45/00; C10G45/58; C10G45/60; C10G45/62; C10G2400/00; C10G2400/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |