US3639441A
Expired / Lapsed
US
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Pentaerythritol-di- and tetra-pivaloyl-diorthosilicic acid-hexa-alkyl esters
Assignee: RUHRCHEMIC AG
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Filing: 1969-10-02
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Granted: 1972-02-01
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Expires: 1989-10-02
Abstract
Abstract DIORTHOSILICIC ACID ESTERS OF THE FORMULA: A(OSI)2(OR'')6 WHEREIN A IS A MONOPENTAERYTHRITOL-DICARBOXYLIC ACID ESTER OR A DIPENTAERYTHRITOL-TETRA-CARBOXYLIC ACID ESTER WHICH ACID HAS A QUATERNARY CARBON ATOM THEREIN AND R'' IS AN ALKYL GROUP OR MORE THAN 3, PREFERABLY AT LEAST 8, CARBON ATOMS; AND LUBRICANTS CONTAINING SUCH.
Inventors
- 👤 Hans Feichtinger
- 👤 Herbert Gothel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:59
CPC Classifications
C; C10; C10M; C10M3/00; C07; C07F; C07F7/00; C07F7/02; C07F7/04; C10M2207/00; C10M2207/04; C10M2207/28; C10M2207/282; C10M2207/34; C10M2209/00; C10M2209/02; C10M2209/10; C10M2223/00; C10M2223/02; C10M2223/04; C10M2223/042; C10M2227/00; C10M2227/02; C10N; C10N2040/00; C10N2040/08
Claims Analysis
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References Cited (Backward Citations)
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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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |