Lubricating oil composition for hybrid vehicles

Abstract

A lubricating oil composition for a hybrid vehicle comprises a majority amount of oil of lubricating viscosity and a carboxylic acid having the formula: 1 -(OR 2 ) n and ethoxylated alcohol demulsifiers represented by the formula R -OH. 1 R is a branched or linear hydrocarbon group having 6 to 20 carbon atoms. 2 is a saturated hydrocarbon group having 2 to 4 carbon atoms, and n is an integer of 1 to 10.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates to lubricating oil compositions and methods of using the lubricating oil compositions. More specifically, the lubricating oil compositions provide rust inhibition benefits in hybrid vehicles. [Background technology]

[0002] Modern lubricants are often formulated according to strict specifications set by OEM manufacturers. This often requires carefully selected lubricant additives to be mixed with a base oil of lubricating viscosity. The classes or types of lubricant additives that may be included in a lubricant composition include, for example, dispersants, detergents, antioxidants, antiwear agents, rust inhibitors, corrosion inhibitors, antifoam agents, and / or friction modifiers. In general, the specific application or use (e.g., hybrid vehicles) will determine the combination of additives that will be formulated into the lubricant composition.

[0003] Hybrid vehicles rely on two very different types of power technologies: an internal combustion engine and an electric motor. The internal combustion engine primarily drives the vehicle at higher speeds. The electric motor drives the vehicle at lower speeds and can also assist the internal combustion engine when extra power is needed. In hybrid vehicles, it is important to have a balanced power distribution between the engine and the electric motor as the vehicle speed increases.

[0004] Hybrid vehicles typically have a start-stop system that shuts off the engine when the vehicle is stopped, and the engine's fuel system is temporarily suspended when the vehicle is only powered by the motor or braking action. As a result, water and fuel buildup in the oil becomes an issue because the engine cannot adequately evaporate the water and fuel. This results in the formation of an unstable emulsion, which negatively impacts engine performance and leads to corrosion / rust of engine parts.

[0005] Due to the significant differences between hybrid vehicles and conventional automobiles, conventional engine oils are not necessarily optimized for use in hybrid vehicles. Thus, there is a need for lubricating oil compositions specifically designed for hybrid vehicles. More specifically, there is a need for lubricating oil compositions that improve the anti-corrosion / rust effects of engine parts in hybrid vehicles. Summary of the Invention

[0006] In one embodiment, a lubricating oil composition for hybrid vehicles comprises a majority amount of oil of lubricating viscosity and an ethoxylated alcohol demulsifier of the formula: R 1 -(OR 2 ) n -OH(in the formula, R 1 is a branched or linear hydrocarbon group having 6 to 20 carbon atoms, R 2 is a saturated hydrocarbon group having 2 to 4 carbon atoms, and n is an integer from 1 to 10.

[0007] In another aspect, a method for reducing corrosion in a hybrid vehicle includes: supplying to an engine of the hybrid vehicle a majority amount of oil of lubricating viscosity and an ethoxylated alcohol demulsifier of the formula: R 1 -(OR 2 ) n -OH(in the formula, R 1 is a branched or linear hydrocarbon group having 6 to 20 carbon atoms, R 2 is a saturated hydrocarbon group having 2 to 4 carbon atoms, and n is an integer from 1 to 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are described in detail herein. It should be understood, however, that the description of specific embodiments herein is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0009] To facilitate understanding of the subject matter disclosed herein, certain terms, abbreviations, or other shorthand notations used herein are defined below. Any term, abbreviation, or shorthand notation not defined will be understood to have its ordinary meaning as used by those of ordinary skill in the art at the time of filing of this application.

[0010] As used herein, the following terms have the following meanings unless otherwise specified:

[0011] By "major amount" it is meant greater than 50% by weight of the composition.

[0012] By "minor amount" is meant less than 50% by weight of the composition, expressed with respect to the additive being listed and with respect to the total weight of all additives present in the composition, considered as the active ingredient of the additive.

[0013] "Active ingredient" or "actives" or "oil-free" refers to additive materials that are not diluents or solvents.

[0014] The term "oil-soluble" means that for a particular additive, the amount required to provide the desired level of activity or performance can be added by dissolving, dispersing or suspending in an oil of lubricating viscosity. Typically, "oil-soluble" means that at least 0.001 wt.% of the additive can be incorporated into a lubricating oil composition. The term "fuel-soluble" is a similar expression that describes an additive that is dissolved, dispersed or suspended in a fuel.

[0015] An "engine" or "combustion engine" is a heat engine in which the combustion of fuel takes place in a combustion chamber. An "internal combustion engine" is a heat engine in which the combustion of fuel takes place in a restricted space (the "combustion chamber"). A "spark ignition engine" is a heat engine in which the combustion is ignited by a spark, usually from a spark plug. This is in contrast to a "compression ignition engine", usually a diesel engine, in which the heat generated by the injection and compression of the fuel is sufficient to initiate combustion without an external spark.

[0016] The term "hydrocarbyl" refers to a chemical group or moiety derived from a hydrocarbon, including saturated and unsaturated hydrocarbons. Examples of hydrocarbyl groups include alkenyl, alkyl, polyalkenyl, polyalkyl, phenyl, and the like.

[0017] All percentages reported are by weight on an active ingredient basis (ie, without regard to carrier or diluent oil) unless otherwise noted.

[0018] All ASTM standards referred to herein are the most current editions as of the filing date of this application.

[0019] The present invention provides lubricating oil compositions that are particularly useful in engines that are subject to corrosion and / or wear, such as engines in hybrid vehicles. The lubricating oil compositions generally comprise (a) a majority amount of oil of lubricating viscosity, and (b) an ethoxylated alcohol demulsifier. Lubricant Additives

[0020] The lubricating oil compositions of the present invention may contain the lubricating oil additives described herein.

[0021] The lubricating oil additive composition of the present invention comprises an ethoxylated alcohol demulsifier having the formula: R 1 -(OR 2 ) n -OH R 1R is a branched or straight chain hydrocarbon group having 6 to 20 carbon atoms (e.g., 8 to 18, 10 to 18, 10 to 16, 12 to 14, etc.). 2 is a saturated hydrocarbon group having 2 to 4 carbon atoms, and n is an integer from 1 to 10 (eg, 2 to 8, 3 to 6, etc.).

[0022] In some embodiments, R 1 The hydrocarbyl group may be an alkyl or alkenyl group. An alkyl group refers to a saturated hydrocarbon group that may be linear, branched, cyclic, or a combination of cyclic, linear, and / or branched. An alkenyl group refers to an unsaturated hydrocarbon group that may be linear, branched, cyclic, or a combination of cyclic, linear, and / or branched.

[0023] In some embodiments, the ethoxylated alcohol demulsifier is a primary alcohol. In some embodiments, the ethoxylated alcohol demulsifier is a secondary alcohol. In some embodiments, the ethoxylated alcohol demulsifier is a tertiary alcohol.

[0024] For illustrative purposes, the following non-limiting examples of ethoxylated alcohol demulsifiers are provided: [ka]

[0025] Typically, the ethoxylated alcohol demulsifier is present in an amount ranging from about 0.15 to about 5.0 wt %, based on the total weight of the lubricating oil composition. In one embodiment, the one or more additive compounds may be present in the lubricating oil composition of the present disclosure in an amount ranging from about 0.15 to about 4.0 wt %, based on the total weight of the lubricating oil composition. In one embodiment, the one or more additive compounds may be present in the lubricating oil composition of the present disclosure in an amount ranging from about 0.15 to about 3.0 wt %, based on the total weight of the lubricating oil composition. In one embodiment, the one or more additive compounds may be present in the lubricating oil composition of the present disclosure in an amount ranging from about 0.15 to about 2.0 wt %, based on the total weight of the lubricating oil composition.

[0026] lubricating oil composition An oil of lubricating viscosity (sometimes referred to as a "base stock" or "base oil") is the primary liquid component of a lubricant into which additives and possibly other oils are mixed to provide, for example, the final lubricant (i.e., lubricant composition). Base oils useful for making concentrates and for making lubricating oil compositions therefrom may be selected from natural (vegetable, animal, or mineral) and synthetic lubricating oils and mixtures thereof.

[0027] The definitions of base stocks and base oils in this disclosure are the same as those set forth in American Petroleum Institute (API) Publication 1509 Annex E ("API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils," December 2016). Group I base stocks contain less than 90% saturates and / or more than 0.03% sulfur and have a viscosity index of 80 or greater and less than 120, using the test methods set forth in Table E-1. Group II base stocks contain 90% or greater saturates and 0.03% or less sulfur and have a viscosity index of 80 or greater and less than 120, using the test methods set forth in Table E-1. Group III base stocks contain 90% or greater saturates and 0.03% or less sulfur and have a viscosity index of 120 or greater, using the test methods set forth in Table E-1. Group IV base stocks are polyalphaolefins (PAOs). Group V base stocks include all other base stocks not included in Groups I, II, III, or IV.

[0028] Natural oils include animal oils, vegetable oils (e.g., castor oil and lard oil), and mineral oils. Animal and vegetable oils with favorable thermo-oxidative stability can be used. Of the natural oils, mineral oils are preferred. Mineral oils vary widely according to their crude source, e.g., paraffinic, naphthenic, or mixed paraffinic and naphthenic. Oils derived from coal or shale are also useful. Natural oils also vary according to the methods used to produce and refine them, e.g., their distillation range, and whether they are straight run, cracked, hydrorefined, or solvent extracted.

[0029] Synthetic oils include hydrocarbon oils, such as polymerized and copolymerized olefins (e.g., polybutylene, polypropylene, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylene-alpha olefin copolymers). Polyalphaolefin (PAO) oil bases are commonly used synthetic hydrocarbon oils. Examples include C8-C 14 Olefins, e.g. C8, C 10 , C 12 , C 14 In some cases, PAOs derived from olefins, or mixtures thereof may be utilized.

[0030] Other useful fluids for use as base oils include non-conventional or unconventional base stocks that have been treated (preferably catalytically) or synthetically to provide high performance properties.

[0031] Unconventional or exotic base stocks / base oils include one or more mixtures of base stock(s) derived from one or more Gas-to-Liquids (GTL) materials, as well as isomer / isodewaxed base stock(s) derived from natural wax or waxy feeds, mineral oil and / or non-mineral oil waxy feeds such as slack wax, natural wax, and waxy base stocks such as gas oil, waxy fuels hydrocracker bottoms, waxy raffinates, hydrocrackates, pyrolysates, or other minerals, mineral oils, or even non-petroleum derived waxy materials such as waxy materials obtained from coal liquids or shale oil, and mixtures of such base stocks.

[0032] The base oils for use in the lubricating oil compositions of the present disclosure can be any of a variety of oils corresponding to API Group I, Group II, Group III, Group IV, and Group V oils and mixtures thereof, preferably API Group II, Group III, Group IV, and Group V oils and mixtures thereof, and more preferably Group III to Group V base oils due to their superior volatility, stability, viscosity, and detergency characteristics.

[0033] Typically, the base oil has a viscosity of 2.5 to 20 mm at 100°C. 2 / s (e.g., 3 to 12 mm 2 / s, 4~10mm 2 / s, or 4.5 to 8 mm 2 / s) range of kinematic viscosity (ASTM D445).

[0034] The lubricating oil composition may also contain conventional lubricant additives to provide auxiliary functions, to obtain a finished lubricating oil composition in which these additives are dispersed or dissolved.For example, the lubricating oil composition may be mixed with antioxidants, ashless dispersants, antiwear agents, detergents such as metal detergents, rust inhibitors, anti-foam agents, demulsifiers, friction modifiers, metal deactivators, pour point depressants, viscosity modifiers, antifoam agents, co-solvents, package compatibility agents, corrosion inhibitors, pigments, extreme pressure agents, etc., and mixtures thereof.Various additives are known and commercially available.These additives or similar compounds may be used in the preparation of the lubricating oil composition of the present invention by conventional blending procedures.

[0035] Each of the above additives, when used, is used in a functionally effective amount to impart the desired properties to the lubricant. Thus, for example, if the additive is an ashless dispersant, a functionally effective amount of the ashless dispersant is an amount sufficient to impart the desired dispersant characteristics to the lubricant. In general, the concentration of each of these additives when used can range from about 0.001 to about 20% by weight, for example, from about 0.01 to about 10% by weight, unless otherwise specified. Additional Lubricant Additives

[0036] The lubricating oil compositions of the present disclosure may contain other conventional additives capable of imparting desired properties to or improving the lubricating oil compositions in which they are dispersed or dissolved. Any additive known to those skilled in the art may be used in the lubricating oil compositions disclosed herein. Some suitable additives are described in Mortier et al., "Chemistry and Technology of Lubricants," 2nd Edition, London, Springer, (1996), and Leslie R. Rudnick, "Lubricant Additives: Chemistry and Applications," New York, Marcel Dekker (2003), both of which are incorporated herein by reference. For example, the lubricating oil composition may be mixed with antioxidants (e.g., alkylated diphenylamines, phenolic antioxidants), antiwear agents, detergents such as metal detergents, rust inhibitors, anti-tarnish agents, demulsifiers, metal deactivators, friction modifiers (e.g., ester-based friction modifiers), viscosity modifiers (e.g., olefin copolymers), pour point depressants, antifoam agents (e.g., silicon-based antifoam agents), co-solvents, corrosion inhibitors, dispersants, multifunctional agents, pigments, extreme pressure agents, and the like, and mixtures thereof. A variety of additives are known and commercially available. These additives, or similar compounds thereof, may be used in the preparation of the lubricating oil composition of the present disclosure by conventional mixing methods.

[0037] In the preparation of lubricating oil formulations, it is common practice to introduce the additives in the form of a 10 to 100% by weight concentrate of the active ingredient in a hydrocarbon-based oil (e.g. a mineral lubricating oil) or other suitable solvent.

[0038] Typically, these concentrates can be diluted with 3 to 100 (e.g., 5 to 40) parts by weight of lubricating oil per part by weight of the additive package to form a finished lubricant (e.g., crankcase motor oil). The purpose of the concentrates, of course, is to reduce the difficulty and awkwardness of handling the various materials and to facilitate dissolution or dispersion in the final mixture.

[0039] Each of the above additives, when used, is used in a functionally effective amount to impart the desired characteristics to the lubricant. Thus, for example, if an additive is a friction modifier, a functionally effective amount of the friction modifier is an amount sufficient to impart the desired friction modifying characteristic to the lubricant.

[0040] Generally, the concentration of each of the additives in the lubricating oil composition, if used, can range from about 0.001% to about 20% by weight, about 0.01% to about 15% by weight, or about 0.1% to about 10% by weight, about 0.005% to about 5% by weight, or about 0.1% to about 2.5% by weight, based on the total weight of the lubricating oil composition. Additionally, the total amount of additives in the lubricating oil composition can range from about 0.001% to about 20% by weight, about 0.01% to about 10% by weight, or about 0.1% to about 5% by weight, based on the total weight of the lubricating oil composition.

[0041] The following examples are presented to illustrate the embodiments of the present disclosure, but are not intended to limit the present disclosure to the specific embodiments described. Unless otherwise specified, all parts and percentages are by weight. All numerical values ​​are approximate. When numerical ranges are given, it should be understood that embodiments outside the ranges described may also fall within the scope of the present invention. The specific details described in each example should not be construed as essential features of the present invention.

[0042] It will be understood that various modifications may be made to the embodiments disclosed herein. Thus, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. For example, the functions described above and implemented as the best mode for operating the invention are for illustrative purposes only. Other configurations and methods may be implemented by those skilled in the art without departing from the scope and spirit of the present disclosure. Moreover, other modifications within the scope and spirit of the appended claims will occur to those skilled in the art. EXAMPLES

[0043] The following examples are for illustrative purposes only and are not intended to limit the scope of the disclosure in any way.

[0044] Each lubricant was evaluated according to the Japanese Industrial Standards (JIS) K2246 test, slightly modified for hybrid vehicle lubricants. In the JIS K2246 test, test specimens are coated with the test oil and the test specimens are examined for rust formation. The modified JIS K2246 test differs from the standard JIS K2246 test only in that the test specimens are coated with a mixture containing the test oil and distilled water. As a result, the modified JIS K2246 test is more suitable for evaluating the expected rust performance of vehicles that are prone to rust (e.g., hybrid vehicles). Table 1 summarizes the modified JIS K2246 test results.

[0045] The test specimens were placed in a humidity cabinet at 49°C and >95% relative humidity (RH) for 72 hours. This test evaluated the ability of the oil to prevent rusting of metal materials or metal products, primarily made of steel.

[0046] The ASTM D1748 test (humidity cabinet rust test) was performed in the same manner. The lower the rust formation rating, the better the corrosion resistance performance. A rating of 10 or less indicates a pass.

[0047] Mixtures containing the test oils and distilled water were prepared according to the following steps. 1. Mix 30 ml of distilled water and 270 ml of test oil in a plastic container. 2. Transfer the test oil and distilled water mixture into a 500 ml container. 3. On the day of the JIS K2246 test, stir the mixture containing the test oil and distilled water, then shake by hand for 30 seconds. 4. Heat the test oil in a 70°C convection oven for 30 minutes. 5. After 30 minutes, remove the test oil from the oven and allow to cool to room temperature. 6. Immediately prior to immersion of the test specimen in the test oil, the test oil is again shaken by hand for 30 seconds. 7.Start JIS K2246 testing. Comparative Example 1

[0048] Lubricating oil compositions were prepared containing a majority of a Group III base oil of lubricating viscosity and the following additives to provide finished oils of 5W-30 SAE viscosity grade: 1. A mixture of borated and non-borated succinimide dispersants; 2. A mixture of overbased and underbased / neutral calcium detergents at 850 ppm (as calcium content); 3.610 ppm (as magnesium content) of an overbased magnesium detergent; 4.810 ppm (as zinc content) of secondary zinc dialkyldithiophosphate; 5. 0.1% by weight of a molybdenum succinimide complex; 6. 1.5% by weight of a mixture of an alkylated diphenylamine antioxidant and a phenolic antioxidant; 7. 0.3 wt. % of an ester-based friction modifier, 8. Small amounts of silicone-based foam inhibitors, olefin copolymer (OCP) viscosity modifiers, and pour point depressants.

[0049] Examples 1 to 5 Examples 1-5 were prepared similarly to Comparative Example 1, except for the addition of 0.5-1.0 wt% of an ethoxylated alcohol demulsifier, which is an ethoxylated secondary alcohol shown in Structure 1. The JIS K2246 results are summarized in Table 1. Examples 1-5, which contain additional demulsifier, show improved rust prevention efficacy compared to the baseline formulation. [Table 1]

[0050] Unless inconsistent with this document, all documents described herein, including any priority documents and / or test procedures, are incorporated herein by reference. As is apparent from the general description and specific embodiments set forth above, although several forms of the present disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, the present disclosure is not intended to be limited thereby.

[0051] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, a range from any lower limit may be combined with any upper limit to enumerate a range not explicitly stated, and a range from any lower limit may be combined with any other lower limit to enumerate a range not explicitly stated, and a range from any upper limit may be combined with any other upper limit to enumerate a range not explicitly stated. Furthermore, a range includes every point or individual value between its endpoints, even if not explicitly enumerated. Thus, every point or individual value may be combined with other points or individual values, or with other lower or upper limits, to act as its own lower or upper limit, enumerating a range not explicitly stated.

[0052] Similarly, the term "comprising" is considered synonymous with the term "including." Similarly, whenever the transitional phrase "comprising" precedes a composition, element, or group of elements, it is understood to also contemplate the same composition or group of elements with the transitional phrase "consisting essentially of," "consisting of," "selected from the group consisting of," or "is," preceding the description of the composition, element, or group of elements, and vice versa.

[0053] As used herein, the terms "a" and "the" are understood to encompass the plural as well as the singular.

[0054] Various terms are defined above. To the extent that a term used in the claims is not defined above, it should be given the broadest definition that a person skilled in the relevant art would give that term, as reflected in at least one printed publication or issued patent. Furthermore, all patents, test methods, and other documents cited in this application are incorporated by reference in their entirety to the extent such disclosure is not inconsistent with this application and in all jurisdictions where such incorporation is permitted.

[0055] The foregoing description of the disclosure illustrates and describes the disclosure. Moreover, the disclosure shows and describes only the preferred embodiments, but as noted above, it is to be understood that the disclosure can be used in various other combinations, modifications, and environments, and that changes or modifications are possible within the scope of the concepts expressed herein, consistent with the teachings above and / or the skill or knowledge of the relevant art. While the foregoing is directed to embodiments of the disclosure, other and further embodiments of the disclosure can be devised without departing from the basic scope thereof, the scope of which is determined by the claims that follow.

[0056] Where combinations, subsets, groups, etc. of elements (e.g., combinations of components in a composition or combinations of steps in a method) are disclosed, it is understood that specific reference to each of the various individual and collective combinations and permutations of those elements is specifically contemplated and described herein, even though it may not be explicitly disclosed.

[0057] The embodiments described herein above are further intended to further describe the best mode known for carrying out the invention and to enable others skilled in the art to utilize the present disclosure in such or other embodiments, with various modifications necessary for a particular application or use. Therefore, the description is not intended to be limited to the forms disclosed herein. Also, it is intended that the appended claims be construed to include alternative embodiments.

Claims

1. A lubricating oil composition for a hybrid vehicle, comprising: a. a majority amount of oil of lubricating viscosity; b. An ethoxylated alcohol demulsifier of the formula: R １ -(O-R ２ ) ｎ -OH (In the formula, R １ is a branched or straight chain hydrocarbon group having 6 to 20 carbon atoms, R ２ is a saturated hydrocarbon group having 2 carbon atoms, and n is an integer from 1 to 10; the ethoxylated alcohol demulsifier is a secondary alcohol; the ethoxylated alcohol demulsifier is present at 0.15 wt % to 5 wt %, based on the total weight of the lubricating oil composition; The lubricating oil composition.

2. R １ But C １２ ~C １４ 10. The lubricating oil composition of claim 1, wherein the hydroxyl group is a hydrocarbyl group.

3. 2. The lubricating oil of claim 1, wherein n is an integer from 3 to 6.

4. 10. The lubricating oil composition of claim 1, further comprising a polar modifier, a dispersant, a detergent, an antiwear agent, an antioxidant, a friction modifier, a viscosity modifier, or a pour point depressant.

5. 1. A method for reducing corrosion in a hybrid vehicle, comprising: a. a majority amount of oil of lubricating viscosity; b. An ethoxylated alcohol demulsifier of the formula: R １ -(O-R ２ ) ｎ -OH (In the formula, R １ is a branched or straight chain hydrocarbon group having 6 to 20 carbon atoms, R ２ is a saturated hydrocarbon group having 2 carbon atoms, and n is an integer from 1 to 10; and the ethoxylated alcohol demulsifier is a secondary alcohol; the ethoxylated alcohol demulsifier is present at 0.15 wt % to 5 wt %, based on the total weight of the lubricating oil composition; The method.

6. R １ is C １２ ~C １４ The method of claim 5, wherein the alkyl group is a hydrocarbyl group.

7. The method of claim 5, wherein n is an integer from 3 to 6.

8. 6. The method of claim 5, wherein the lubricating oil composition further comprises a polar modifier, a dispersant, a detergent, an antiwear agent, an antioxidant, a friction modifier, a viscosity modifier, or a pour point depressant.

9. A method for reducing corrosion in a hybrid vehicle to a passing rating of 10 or less as determined according to a modified JIS K2246 test, comprising: R 1 -(O-R 2 ) n -OH wherein R 1 is a branched or straight chain hydrocarbon group having 6 to 20 carbon atoms, R 2 is a saturated hydrocarbon group having 2 to 4 carbon atoms, and n is an integer from 1 to 10, The lubricating oil composition is supplied to an engine of the hybrid vehicle, The method of claim 1, wherein the alkoxylated alcohol demulsifier is present at 0.15 wt % to 5 wt %, based on the total weight of the lubricating oil composition.

10. A method for reducing corrosion in a hybrid vehicle to a passing rating of 10 or less as determined in accordance with a modified JIS K2246 test, comprising: R 1 -(O-R 2 ) n -OH wherein R 1 is a branched or linear hydrocarbon group having from 6 to 20 carbon atoms, R 2 is a saturated hydrocarbon group having from 2 to 4 carbon atoms, and n is an integer from 1 to 10, in a lubricating oil composition for a hybrid vehicle, comprising: The lubricating oil composition is supplied to an engine of the hybrid vehicle, The method of claim 1, wherein the alkoxylated alcohol demulsifier is present at 0.15 wt % to 5 wt %, based on the total weight of the lubricating oil composition.

11. The method of claim 9 or 10, wherein the alkoxylated alcohol demulsifier is an ethoxylated secondary alcohol.