Patent US4210541A successfully refreshed from Google Patents.
US4210541A
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Stabilized hydraulic fluid composition
Assignee: Chevron USA Inc
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Filing: 1978-11-27
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Granted: 1980-07-01
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Expires: 1998-11-27
Abstract
Abstract Mineral oil or synthetic hydrocarbon base hydraulic fluids containing a zinc bis(dialkyldithiophosphate) as an antiwear agent are stabilized against degradation at elevated operating temperatures by the incorporation in the hydraulic fluid of an appropriate Group I or Group II metal dialkylnaphthalene sulfonate and a fatty acid imidazoline. For example, a hydraulic fluid containing a zinc bis(dialkyldithiophosphate) is stabilized by the presence of a minor amount of zinc dinonylnaphthalene sulfonate and a tallow fatty acid imidazoline.
Inventors
- 👤 James T. Mann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:15
CPC Classifications
C; C10; C10M; C10M141/00; C10M141/10; C10M2205/00; C10M2205/02; C10M2205/028; C10M2207/00; C10M2207/02; C10M2207/023; C10M2207/026; C10M2215/00; C10M2215/22; C10M2215/223; C10M2215/224; C10M2219/00; C10M2219/04; C10M2219/044; C10M2223/00; C10M2223/02; C10M2223/04; C10M2223/045; C10M2229/00; C10M2229/02; C10M2229/04; C10M2229/041; C10M2229/05; C10N; C10N2010/00; C10N2010/02; C10N2010/04; C10N2040/00; C10N2040/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
159 words
A hydraulic fluid stabilized against thermal degradation comprising a base oil having a 100° F. (37.8° C.) viscosity of between about 100 SUS (20.6 cs.) and about 1,000 SUS (215 cs.) and selected from highly refined mineral oils, alpha-olefin oligomers and mixtures thereof; from about 0.1 to about 2.0 volume percent of a zinc bis(dialkyldithiophosphate) in which the alkyl groups have between about four and about twelve carbon atoms; from about 0.01 to about 1.0 volume percent of a metal dialkylnaphthalene sulfonate in which the metal is selected from lithium, sodium, magnesium, calcium, barium and zinc and the alkyl groups contain between about six and about twenty carbon atoms; and from about 0.01 to about 1.0 weight percent of a composition having the general formula ##STR2## where n is an integer selected from 0, 1, 2 and 3 and R is selected from alkyl, alkenyl, alkadienyl, alkatrienyl, and mixtures thereof having from about ten to about thirty carbon atoms.
Claim 2
Dependent Claim
159 words
A hydraulic fluid stabilized against thermal degradation comprising a base oil having a 100° F. (37.8° C.) viscosity of between about 100 SUS (20.6 cs.) and about 1,000 SUS (215 cs.) and selected from highly refined mineral oils, alpha-olefin oligomers and mixtures thereof; from about 0.1 to about 2.0 volume percent of a zinc bis(dialkyldithiophosphate) in which the alkyl groups have between about four and about twelve carbon atoms; from about 0.01 to about 1.0 volume percent of a metal dialkylnaphthalene sulfonate in which the metal is selected from lithium, sodium, magnesium, calcium, barium and zinc and the alkyl groups contain between about six and about twenty carbon atoms; and from about 0.01 to about 1.0 weight percent of a composition having the general formula ##STR2## where n is an integer selected from 0, 1, 2 and 3 and R is selected from alkyl, alkenyl, alkadienyl, alkatrienyl, and mixtures thereof having from about ten to about thirty carbon atoms.
Claim 3
Dependent Claim
146 words
A hydraulic fluid stabilized against thermal degradation comprising a base oil having a 100° F. (37.8° C.) viscosity of between about 100 SUS (20.6 cs.) and about 1,000 SUS (215 cs.) and selected from highly refined mineral oils, alpha-olefin oligomers and mixtures thereof; from about 0.1 to about 2.0 volume percent of a zinc bis(dialkyldithiophosphate) in which the alkyl groups have between about four and about twelve carbon atoms; from about 0.01 to about 1.0 volume percent of a zinc dialkylnaphthalene sulfonate in which the alkyl groups contain between about six and about twenty carbon atoms, and from about 0.01 to about 1.0 weight percent of a composition having the general formula ##STR3## where n is an integer selected from 0, 1, 2 and 3 and R is selected from alkyl, alkenyl, alkadienyl, alkatrienyl, and mixtures thereof having from about ten to about thirty carbon atoms.
Claim 4
Dependent Claim
146 words
A hydraulic fluid stabilized against thermal degradation comprising a base oil having a 100° F. (37.8° C.) viscosity of between about 100 SUS (20.6 cs.) and about 1,000 SUS (215 cs.) and selected from highly refined mineral oils, alpha-olefin oligomers and mixtures thereof; from about 0.1 to about 2.0 volume percent of a zinc bis(dialkyldithiophosphate) in which the alkyl groups have between about four and about twelve carbon atoms; from about 0.01 to about 1.0 volume percent of a zinc dialkylnaphthalene sulfonate in which the alkyl groups contain between about six and about twenty carbon atoms, and from about 0.01 to about 1.0 weight percent of a composition having the general formula ##STR3## where n is an integer selected from 0, 1, 2 and 3 and R is selected from alkyl, alkenyl, alkadienyl, alkatrienyl, and mixtures thereof having from about ten to about thirty carbon atoms.
Claim 5
Dependent Claim
33 words
A hydraulic fluid stabilized against thermal degradation in accordance with claims 1 or 2 in which the alkyl groups in the zinc bis(dialkyldithiophosphate) compound have between about seven and about nine carbon atoms.
Claim 6
Dependent Claim
46 words
A hydraulic fluid stabilized against thermal degradation in accordance with claims 1 or 2 in which alkyl groups in the metal dialkylnaphthalene sulfonate have between about eight and about twelve carbon atoms, R has between about 12 and about 18 carbon atoms and n is 1.
Claim 7
Dependent Claim
31 words
A hydraulic fluid stabilized against thermal degradation in accordance with claims 1 or 2 in which there is between about 0.05 and about 0.5 volume percent of the metal dialkylnaphthalene sulfonate.
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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) | 1983-07-01 | 1983-12-31 | 1984-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-01 | 1987-12-31 | 1988-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-01 | 1991-12-31 | 1992-07-01 | $7700.00 | Window Closed / Lapsed |