Cooling and flame-retardant lubricating composition for a propulsion system of an electric or hybrid vehicle
The present invention relates to a composition for lubricating a propulsion system of an electric or hybrid vehicle, comprising at least one base oil and at least one fire retardant corresponding to formula (I) R F -L-R H (I) in which R F is a perfluorinated or partially fluorinated group, R H is a hydrocarbon-based group, and L is a linker. The invention also relates to the use of at least one fire retardant of formula (I), in a composition for lubricating a propulsion system of an electric or hybrid vehicle, including at least one battery, to give it ignition-resistance properties. Finally, the invention relates to a process for cooling and fire-protecting a battery of a propulsion system of an electric or hybrid vehicle, comprising at least one step of placing at least one battery, in particular a lithium-ion or nickel-cadmium battery, in contact with a composition according to the invention.
1. A composition for lubricating a propulsion system of an electric or hybrid vehicle, comprising:
at least one base oil; and
at least one fire retardant represented by formula (I):
R F -L-R H (I),
in which,
R F is a perfluorinated or partially fluorinated group,
R H is a hydrocarbon-based group, and
L is a linker chosen from the following: —CH 2 —, —CH═CH—, —O—, —S—, or —PO 4 —,
wherein the composition has a kinematic viscosity of between 2 and 8 mm 2 /s, measured at 100° C. according to the standard ASTM D445.
2. The composition as claimed in claim 1 , wherein R H includes between 3 and 22 carbon atoms.
3. The composition as claimed in claim 1 , wherein:
R F is a perfluorinated or partially fluorinated (C 1 -C 16 )alkyl group, optionally interrupted with one or two heteroatoms independently chosen from a nitrogen atom and an oxygen atom; and
R H is a (C 1 -C 15 )alkyl group, or (C 2 -C 15 )alkenyl group that is optionally substituted with a (C 3 -C 6 )cycloalkyl, phenyl, or benzyl group.
4. The composition as claimed in claim 1 , wherein the composition comprises the fire retardant in an amount of between 0.5% and 40% by weight, relative to the total weight of the composition.
5. The composition as claimed in claim 1 , wherein the base oil has a kinematic viscosity ranging from 1.5 to 8 mm 2 /s, measured at 100° C. according to the standard ASTM D445.
6. The composition as claimed in claim 1 , wherein the base oil is chosen from synthetic oils, poly-α-olefins, or polyalkylene glycols obtained by polymerization or copolymerization of alkylene oxides comprising from 2 to 8 carbon atoms.
7. The composition as claimed in claim 1 , wherein:
the composition comprises from 60% to 99.5% by weight of the base oil, relative to the total weight of the composition; and
the base oil has a kinematic viscosity ranging from 1.5 to 8 mm 2 /s, measured at 100° C. according to the standard ASTM D445.
8. The composition as claimed in claim 1 , further comprising at least one additive chosen from friction modifiers, detergents, anti-wear additives, extreme-pressure additives, dispersants, antioxidants, pour-point improvers, antifoam agents, or mixtures thereof.
9. The composition as claimed in claim 1 , further comprising at least one free-radical inhibitor and/or at least one additional fire retardant.
10. The composition as claimed in claim 9 , wherein:
the free-radical inhibitor is chosen from compounds in the form of a pentavalent phosphorus of the phosphate or phosphazene family or in the form of a trivalent phosphorus of the phosphite family; and
the additional fire retardant is chosen from halogenated compounds other than fluoro compounds.
11. A method for giving ignition-resistance properties to a composition for lubricating a propulsion system of an electric or hybrid vehicle including at least one battery, comprising:
adding into the composition at least one fire retardant as claimed in claim 1 ; and
lubricating the propulsion system with the composition.
12. The method as claimed in claim 11 , wherein the composition further comprises at least one free-radical inhibitor and/or at least one additional fire retardant.
13. The method as claimed in claim 11 , wherein the composition comprises between 0.5% and 40% by weight of the fire retardant, relative to the total weight of the composition.
14. A process for cooling and/or fire-protecting a battery of a propulsion system of an electric or hybrid vehicle, comprising contacting the battery with a composition as claimed in claim 1 .
15. The process as claimed in claim 14 , wherein contacting the battery comprises:
completely or partially immersing the battery in a static or circulating amount of the composition; and/or
injecting, jetting, misting, and/or spraying the composition on the battery using pressure or gravity.
16. The composition as claimed in claim 1 , wherein:
R F is a perfluorinated or partially fluorinated group including from 1 to 16 carbon atoms; and
R H is a hydrocarbon-based group including from 1 to 16 carbon atoms.
17. The composition as claimed in claim 1 , wherein the composition comprises between 3% and 10% by weight of the fire retardant, relative to the total weight of the composition.
18. The composition as claimed in claim 1 , wherein the base oil has a kinematic viscosity ranging from 1.5 to 2.1 mm 2 /s, measured at 100° C. according to the standard ASTM D445.
19. The composition as claimed in claim 1 , wherein:
the composition comprises from 90% to 97% by weight of base oil, relative to the total weight of the composition; and
the base oil has a kinematic viscosity ranging from 1.5 to 8 mm 2 /s, measured at 100° C. according to the standard ASTM D445.