EP-4739757-A1 - LUBRICATING OIL COMPOSITION

Abstract

The invention provides lubricating oil composition comprising a base oil composition and a friction modifier, said base oil composition comprising i. a first base oil selected from Fischer-Tropsch derived Group III base oils; and ii. no more than 25wt%, based on the overall weight of the lubricating oil composition, of a further base oil consisting of a monoester base oil, wherein the friction modifier is present in an amount in the range of from 0.25 to 2.5wt% based on the overall weight of the lubricating oil composition and is selected from a glycerol mono ester and a mono ester amine salt of formula (I) wherein R is selected from a saturated or unsaturated C4 to C22 hydrocarbon group, R1 is selected from a saturated or unsaturated C1 to C24 hydrocarbon group and n is an integer in the range of from 1 to 4, and wherein the lubricating oil composition has a kinematic viscosity at 100˚C in the range of from 1.5 to 4.0 mm 2 /s, a flash point, measured by the open cup method, of at least 160˚C and an aniline point of at least 80˚C.

Inventors

• UEDA, Mao

Assignees

• Shell Internationale Research Maatschappij B.V.

Dates

Publication Date

20260513

Application Date

20240628

Claims (1)

1. SP3011 - 16 - C L A I M S 1. A lubricating oil composition comprising a base oil composition and a friction modifier, said base oil composition compris ing i. a first b ase oil selecte d from F ischer-Tropsch 5 derived Group III base oi ls; and ii. no more than 25wt%, based on the overall weight of the lubricating oil composition, of a further base oil consisting of a monoester base oil, wherein the friction modifier is present in an amount in 10 the range of from 0.25 to 2.5wt% based on the overall weight of the lubricating oil composition and is selected from a glycerol mono ester and a mono ester amine salt of formula (I) 15 wherein R is or unsaturated C4 to C22 hydrocarbo grou p, is selected from a saturated or unsaturated C1 to C24 hydrocarbon group and n is an integer in the range of from 1 to 4, and wherein the lubricating oil composition has a 20 kinematic viscosity at 100˚C in the range of from 1.5 to 4.0 mm 2 /s, a flash point, measured by the open cup method, of at least 160˚C and an aniline point of at least 80˚C. 2. A lubricating oil as claimed in Claim 1, wherein the lubricating oil composition contains at least 25 0.025 wt% of phosphorus based on the overall weight of the composition. 3. A lubricating oil composition as claimed in Claim 1 or Claim 2, wherein the Fischer-Tropsch derived Group III base oil has a kinematic viscosity at 100°C in the range of from 1.5 to 4.5 mm 2 /s, preferably in the range of from 1.5 to 4.0 mm 2 /s. 4. A lubricating oil composition as claimed in any one of Claims 1 to 3, wherein the monoester base oil is present 5 in an amount of at least 5wt%, preferably at least 10wt%, more preferably at least 15wt%. 5. A lubricating oil composition as claimed in any one of Claims 1 to 4, wherein the friction modifier is present in an amount in the range of from 0.5 to 2.0wt% based on the 10 overall weight of the lubricating oil composition. 6. Use of a lubricating oil composition as claimed in any one of Claims 1 to 5 as a reduction gear oil in an electric vehicle. 15

Description

SP3011 - 1 - LUBRICATING OIL COMPOSITION Field of the Invention This invention relates to a lubricating oil composition and the use of said lubricating oil composition as a reduction gear oil in an electric 5 vehicle. Background of the invention E-mobility refers to vehicles powered, at least in part, by batteries, including fully battery powered electric vehicles and the complete range of hybrid 10 vehicles (e.g. plug-in hybrids, series hybrids, etc.). The number of these vehicles on the road has increased rapidly in recent years and it is expected that the rate of take up of vehicles relying on some form of battery power will continue to increase considerably over the coming decades. 15 The growth of, at least partially, electric vehicles has led to increased demands for fluids suitable for use in the powertrain of such vehicles. There is less uniformity between different types of electric vehicle (EV) powertrains than there is in internal combustion 20 engine (ICE) vehicles . In part, this is due to the degree of electrification of any vehicle, but also on the differences in design of the powertrain for vehicles with similar levels of electrification by different manufacturers. The design of fluids suitable for a range 25 of e-mobility options contains many challenges. Transmissions in pure battery-operated vehicles (BEVs) typically have a simple reduction gear set. Such vehicles have higher torques at low speeds and much higher rotational speeds than ICE powertrains. The absence of an 30 internal combustion engine usually means that BEVs operate at lower temperatures than ICE vehicles. Creating fluids to perform effectively in these conditions is a challenge. The provision of a lubricating oil composition for a reduction gear set in an electric or hybrid electric vehicle requires a careful balance in order to provide a 5 low viscosity composition which still provides excellent friction characteristics. Typically, lowering the viscosity of a lubricating oil composition negatively impacts on performance characteristics such as flash point and anti-wear performance. The use of friction modifiers 10 often leads to copper corrosion, potentially damaging key componentry in an electric or hybrid vehicle. JP2019-0137829 describes a lubricating oil composition for electric vehicles comprising, in addition to base oil, a phosphite or an amine salt thereof, a 15 borate, a sulfur-based extreme pressure agent and an organic friction modifier. Further improvements, such as the improvement of efficiency by reducing friction without compromising other performance such as flash point, wear protection and 20 copper corrosion, are still required to provide the necessary characteristics for a lubricating oil composition suitable for use as a reduction gear oil in an electric vehicle. Summary of the Invention 25 The present invention provides a lubricating oil composition comprising a base oil composition and a friction modifier, said base oil composition comprising: i. a first base oil selected from Fischer-Tropsch derived Group III base oils; and 30 ii. no more than 25wt%, based on the overall weight of the lubricating oil composition, of a further base oil consisting of a monoester base oil, wherein the friction modifier is present in an amount in the range of from 0.25 to 2.5wt% based on the overall weight of the lubricating oil composition and is selected from a glycerol mono ester and a mono ester amine salt of formula (I) 5 wherein R is or unsaturated C4 to C22 hydrocarbo grou p is selected from a saturated or unsaturated C1 to C24 hydrocarbon group and n is an integer in the range of from 1 to 4, and wherein the lubricating oil composition has a 10 kinematic viscosity at 100˚C in the range of from 1.5 to 4.0 mm2/s, a flash point, measured by the open cup method, of at least 160˚C and an aniline point of at least 80˚C. The present invention also provides the use of such a lubricating oil as a reduction gear oil in 15 an electric vehicle. Detailed Description of the Invention One or more specific embodiments of the present disclosure will be described below. These described embodiments are examples of the presently disclosed 20 techniques. Additionally, in an effort to provide a concise description of these embodiments, not all features of an actual implementation may be described in the specification. When introducing elements of various embodiments of 25 the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 30 Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. In the conte