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Patent US3965019A successfully refreshed from Google Patents.
US3965019A
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Lubricating compositions containing hydrogenated block copolymers as viscosity index improvers
Assignee: Shell USA Inc
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Filing: 1974-12-19
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Granted: 1976-06-22
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Expires: 1994-12-19
Abstract
Abstract Lubricating compositions having improved operating life comprise lubricants containing hydrogenated polymers of conjugated dienes wherein at least 98% of the olefinic double bonds present in the non-hydrogenated precursors are reduced and at least 20% of the polymeric molecules contain no olefinic double bonds in the polymer backbone.
Inventors
- 👤 David J. St. Clair
- 👤 Ronald K. Crossland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:06
CPC Classifications
C; C10; C10M; C10M1/00; C10M1/08; C10M143/00; C10M143/12; C10M2205/00; C10M2205/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
65 words
A lubricating composition comprising a major proportion of a petroleum lubricating oil and from about 0.1% to about 10% by weight of a selectively hydrogenated block copolymer having the structure polystyrene-hydrogenated polyisoprene wherein at least 98% of the olefinic double bonds present in the non-hydrogenated precursor of said polymer are reduced by hydrogenation, at least 20% of the polymer chains containing no in-chain olefinic unsaturation.
Claim 2
Dependent Claim
65 words
A lubricating composition comprising a major proportion of a petroleum lubricating oil and from about 0.1% to about 10% by weight of a selectively hydrogenated block copolymer having the structure polystyrene-hydrogenated polyisoprene wherein at least 98% of the olefinic double bonds present in the non-hydrogenated precursor of said polymer are reduced by hydrogenation, at least 20% of the polymer chains containing no in-chain olefinic unsaturation.
Claim 3
Dependent Claim
19 words
A composition according to claim 1 wherein at least 50% of the polymeric chains contain no in-chain olefinic unsaturation.
Claim 4
Dependent Claim
19 words
A composition according to claim 1 wherein at least 70% of the polymeric chains contain no in-chain olefinic unsaturation.
References Cited (Backward Citations)
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Cited
US3630905A
Cited
US3595942A
Cited
US3763044A
Cited
US3775329A
Cited
US3772196A
Cited
US3835053A
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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) | 1979-06-22 | 1979-12-22 | 1980-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-22 | 1983-12-22 | 1984-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-22 | 1987-12-22 | 1988-06-22 | $7700.00 | Window Closed / Lapsed |