US3554911A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Viscosity index improvers
Assignee: Phillips Petroleum Co
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Filing: 1967-11-30
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Granted: 1971-01-12
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Expires: 1987-11-30
Abstract
Abstract SHEAR-STABLE, HIGH VISCOSITY INDEX LUBRICATING OIL FORMULATIONS ARE FORMED BY THE ADDITION OF A SMALL AMOUNT OF A HYDROGENATED RANDOM BUTADIENE-STYRENE COPOLYMER HAVING A BUTADIENE CONTENT OF 30 TO 44 WEIGHT PERCENT.
Inventors
- 👤 Sidney Schiff
- 👤 Marvin M Johnson
- 👤 William L Streets
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:54
CPC Classifications
C; C10; C10M; C10M143/00; C10M143/12; C08; C08F; C08F8/00; C08F8/04; C10M2203/00; C10M2203/10; C10M2205/00; C10M2205/06; C10M2207/00; C10M2207/02; C10M2207/023; C10M2209/00; C10M2209/02; C10M2209/08; C10M2209/084; C10M2215/00; C10M2215/086; C10M2215/24; C10M2215/28; C10M2219/00; C10M2219/04; C10M2219/044; C10M2219/046; C10M2223/00; C10M2223/02; C10M2223/04; C10M2223/045; C10N; C10N2010/00; C10N2010/04; C10N2040/00; C10N2040/08
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) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |