US4036910A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Block copolymers as viscosity index improvers for lubrication oils
Assignee: Shell USA Inc
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Filing: 1973-03-14
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Granted: 1977-07-19
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Expires: 1993-03-14
Abstract
Abstract Certain two-block copolymers have been found to be highly effective viscosity index improving additives for mineral oils and are especially effective at elevated temperatures.
Inventors
- 👤 William S. Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:49
CPC Classifications
C; C10; C10M; C10M143/00; C10M143/02; C10M143/10; C10M143/12; C10M2205/00; C10M2205/02; C10M2205/022; C10M2205/04; C10M2205/06; C10M2207/00; C10M2207/04; C10M2207/28; C10M2207/282; C10M2207/34; C10M2209/00; C10M2209/10; C10M2209/103; C10M2209/104; C10M2215/00; C10M2215/02; C10M2215/04; C10M2215/086; C10M2215/24; C10M2215/26; C10M2215/28; C10M2217/00; C10M2217/02; C10M2217/04; C10M2217/046; C10M2217/06; C10M2219/00; C10M2219/04; C10M2219/044; C10M2219/046; C10M2219/06; C10M2219/062; C10M2219/066; C10M2219/068; C10M2223/00; C10M2223/02; C10M2223/04; C10M2223/045; C10M2229/00; C10M2229/02; C10M2229/04; C10M2229/05; C10N; C10N2010/00; C10N2010/04; C10N2040/00; C10N2040/02; C10N2040/08; C10N2050/00; C10N2050/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
58 words
As a new composition of matter, a block copolymer having the configuration polystyrene-hydrogenated polyisoprene wherein the polystyrene block has an average molecular weight between about 5,000 and 50,000 and the hydrogenated polyisoprene block has an average molecular weight between about 10,000 and 1,000,000, at least 50% of the double bonds of the polyisoprene block being reduced by hydrogenation.
Claim 2
Dependent Claim
58 words
As a new composition of matter, a block copolymer having the configuration polystyrene-hydrogenated polyisoprene wherein the polystyrene block has an average molecular weight between about 5,000 and 50,000 and the hydrogenated polyisoprene block has an average molecular weight between about 10,000 and 1,000,000, at least 50% of the double bonds of the polyisoprene block being reduced by hydrogenation.
Claim 3
Dependent Claim
51 words
A block copolymer according to claim 1 wherein the polystyrene block has an average molecular weight between about 9,000 and 35,000 and the hydrogenated polyisoprene block has an average molecular weight between about 15,000 and 200,000, at least 80% of the double bonds of the polyisoprene block being reduced by hydrogenation.
References Cited (Backward Citations)
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Cited
US3598886A
Cited
US3595942A
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US3700748A
Cited
US3696088A
Cited
US3700633A
Cited
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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) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |