Patent Description:
Modern lubricating oils are formulated to exacting specifications often set by original equipment manufacturers. This often requires blending carefully selected lubricant additives with base oils of lubricating viscosity. The classes or types of lubricant additives found in lubricating oil compositions include, for example, dispersants, detergents, antioxidants, wear inhibitors, rust inhibitors, corrosion inhibitors, foam inhibitors, and/or friction modifiers. The specific application or use (e.g., hybrid vehicles) will typically govern the set of additives that goes into a lubricating oil composition.

Hybrid vehicles rely on two distinctly different types of motive technologies - internal combustion engine and electric motor. The internal combustion engine mainly drives the vehicle at high speeds. The electric motor drives the vehicle at low speeds and can also assist the internal combustion engine when additional power is needed. It is important for hybrid vehicles to distribute power from the engine and the motor in a well-balanced manner as the vehicle speed increases.

Hybrid vehicle typically feature a start-stop system in which the engine stops when the vehicle comes to a stop and the engine fuel system suspends when the vehicle is driven only by motor or braking. Consequently, accumulation of water and fuel in the oil is a problem as the engine is not able to sufficiently evaporate the water and fuel. This results in the formation of unstable emulsions which negatively impacts engine performance and leads to corrosion/rust in engine parts.

The differences between hybrid vehicles and conventional automobile vehicles are significant enough that conventional engine oils are not optimized for use in hybrid vehicles. As a result, lubricating oil compositions designed specifically for hybrid vehicles are needed. More particularly, there is a need for lubricating oil compositions that improve corrosion/rust protection of engine parts in hybrid vehicles.

<CIT> discloses an internal combustion engine lubricating oil composition which is used for improving the ability of a lubricating oil contaminated with water and fuel to reduce corrosion in the engine of a hybrid vehicle.

In one aspect, there is provided a lubricating oil composition for hybrid vehicles comprising: a major amount of an oil of lubricating viscosity; an ethoxylated alcohol demulsifier of the following formula: R<NUM>-(O-R<NUM>)n-OH wherein R<NUM> is a branched or linear hydrocarbon group having from <NUM> to <NUM> carbon atoms, R<NUM> is a saturated hydrocarbon group having <NUM> carbon atoms, and n is an integer from <NUM> to <NUM>.

In another aspect, there is provided a method of reducing corrosion in hybrid vehicle, the method comprising: supplying to the engine of the hybrid vehicle a lubricating oil composition comprising: a major amount of an oil of lubricating viscosity; an ethoxylated alcohol demulsifier of the following formula: R<NUM>-(O-R<NUM>)n-OH wherein R<NUM> is a branched or linear hydrocarbon group having from <NUM> to <NUM> carbon atoms, R<NUM> is a saturated hydrocarbon group having <NUM> carbon atoms, and n is an integer from <NUM> to <NUM>.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are herein described in detail. It should be understood, however, that the description herein of specific embodiments 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 scope of the disclosure as defined by the appended claims.

As used herein, the following terms have the following meanings, unless expressly stated to the contrary.

A "major amount" means in excess of <NUM> weight % of a composition.

A "minor amount" means less than <NUM> weight % of a composition, expressed in respect of the stated additive and in respect of the total mass of all the additives present in the composition, reckoned as active ingredient of the additive or additives.

"Active ingredients" or "actives" or "oil free" refers to additive material that is not diluent or solvent.

The term "oil soluble" means that for a given additive, the amount needed to provide the desired level of activity or performance can be incorporated by being dissolved, dispersed or suspended in an oil of lubricating viscosity. Usually, this means that at least <NUM>% by weight of the additive can be incorporated in a lubricating oil composition. The term "fuel soluble" is an analogous expression for additives dissolved, dispersed or suspended in fuel.

An "engine" or a "combustion engine" is a heat engine where the combustion of fuel occurs in a combustion chamber. An "internal combustion engine" is a heat engine where the combustion of fuel occurs in a confined space ("combustion chamber"). A "spark ignition engine" is a heat engine where the combustion is ignited by a spark, usually from a spark plug. This is contrast to a "compression-ignition engine," typically a diesel engine, where the heat generated from compression together with injection of fuel is sufficient to initiate combustion without an external spark.

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

All percentages reported are weight % on an active ingredient basis (i.e., without regard to carrier or diluent oil) unless otherwise stated.

All ASTM standards referred to herein are the most current versions as of the filing date of the present application.

The present invention provides a lubricating oil composition that is useful for engines that are particularly susceptible to corrosion and/or wear (e.g., engines in hybrid vehicles). The lubricating oil composition generally comprise: (a) a major amount of an oil of lubricating viscosity; and (b) an ethoxylated alcohol demulsifier.

The lubricating oil composition of the present invention may include lubricating oil additives described herein.

A lubricating oil additive composition of the present invention includes an alcohol demulsifier having the following formula:.

R<NUM> is a branched or linear hydrocarbyl group having from <NUM> to <NUM> carbon atoms (such as from <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, and so forth). R<NUM> is a saturated hydrocarbon group having from <NUM> to <NUM> carbon atoms and n is an integer from <NUM> to <NUM> (such as from <NUM> to <NUM>, <NUM> to <NUM>, and the like).

In some embodiments, the R<NUM> hydrocarbyl group can be an alkyl group or an alkenyl group. Alkyl groups refer to saturated hydrocarbyl groups, which can be linear, branched, cyclic, or a combination of cyclic, linear and/or branched. Alkenyl groups refer to unsaturated hydrocarbyl groups, which can be linear, branched, cyclic, or a combination of cyclic, linear and/or branched.

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.

For illustrative purposes, the following non-limiting examples of the ethoxylated alcohol demulsifier are provided. <CHM>
<CHM>
<CHM>.

The alcohol demulsifier is present in an amount ranging from about <NUM> to about <NUM> wt. %, based on the total weight of the lubricating oil composition. In one embodiment, the one or more additive compounds can be present in the lubricating oil composition of the present disclosure in an amount ranging from about <NUM> to about <NUM> wt. %, based on the total weight of the lubricating oil composition. In one embodiment, the one or more additive compounds can be present in the lubricating oil composition of the present disclosure in an amount ranging from about <NUM> to about <NUM> wt. %, based on the total weight of the lubricating oil composition. In another embodiment, the one or more additive compounds can be present in the lubricating oil composition of the present disclosure in an amount ranging from about <NUM> to about <NUM> wt. %, based on the total weight of the lubricating oil composition.

Definitions for the base stocks and base oils in this disclosure are the same as those found in American Petroleum Institute (API) Publication <NUM> Annex E ("API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils," December <NUM>). Group I base stocks contain less than <NUM>% saturates and/or greater than <NUM>% sulfur and have a viscosity index greater than or equal to <NUM> and less than <NUM> using the test methods specified in Table E-<NUM>. Group II base stocks contain greater than or equal to <NUM>% saturates and less than or equal to <NUM>% sulfur and have a viscosity index greater than or equal to <NUM> and less than <NUM> using the test methods specified in Table E-<NUM>. Group III base stocks contain greater than or equal to <NUM>% saturates and less than or equal to <NUM>% sulfur and have a viscosity index greater than or equal to <NUM> using the test methods specified in Table E-<NUM>. Group IV base stocks are polyalphaolefins (PAO). Group V base stocks include all other base stocks not included in Group I, II, III, or IV.

Synthetic oils include hydrocarbon oil. Hydrocarbon oils include oils such as polymerized and interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylene-alphaolefin copolymers). Polyalphaolefin (PAO) oil base stocks are commonly used synthetic hydrocarbon oil. By way of example, PAOs derived from C<NUM> to C<NUM> olefins, e.g., C<NUM>, C<NUM>, C<NUM>, C<NUM> olefins or mixtures thereof, may be utilized.

Typically, the base oil will have a kinematic viscosity at <NUM> (ASTM D445) in a range of <NUM> to <NUM><NUM>/s (e.g., <NUM> to <NUM><NUM>/s, <NUM> to <NUM><NUM>/s, or <NUM> to <NUM><NUM>/s).

The present lubricating oil compositions may also contain conventional lubricant additives for imparting auxiliary functions to give a finished lubricating oil composition in which these additives are dispersed or dissolved. For example, the lubricating oil compositions can be blended with antioxidants, ashless dispersants, anti-wear agents, detergents such as metal detergents, rust inhibitors, dehazing agents, demulsifying agents, friction modifiers, metal deactivating agents, pour point depressants, viscosity modifiers, antifoaming agents, co-solvents, package compatibilizers, corrosion-inhibitors, dyes, extreme pressure agents and the like and mixtures thereof. A variety of the additives are known and commercially available. These additives, or their analogous compounds, can be employed for the preparation of the lubricating oil compositions of the invention by the usual blending procedures.

Each of the foregoing additives, when used, is used at a functionally effective amount to impart the desired properties to the lubricant. Thus, for example, if an additive is an ashless dispersant, a functionally effective amount of this ashless dispersant would be an amount sufficient to impart the desired dispersancy characteristics to the lubricant. Generally, the concentration of each of these additives, when used, may range, unless otherwise specified, from about <NUM> to about <NUM> wt %, such as about <NUM> to about <NUM> wt %.

The lubricating oil compositions of the present disclosure may also contain other conventional additives that can impart a desirable property to or improve the lubricating oil composition in which these additives are dispersed or dissolved. Any additive known to a person of ordinary skill in the art may be used in the lubricating oil compositions disclosed herein. Some suitable additives have been described in <NPL>); and <NPL>). For example, the lubricating oil compositions can be blended with antioxidants (e.g., alkylated diphenylamine, phenolic antioxidants), anti-wear agents, detergents such as metal detergents, rust inhibitors, dehazing agents, demulsifying agents, metal deactivating agents, friction modifiers (e.g., ester-based friction modifier), viscosity modifiers (e.g., olefin copolymer), pour point depressants, antifoaming agents (e.g., silicon-based foam inhibitors), co-solvents, corrosion-inhibitors, dispersants, multifunctional agents, dyes, extreme pressure agents and the like and mixtures thereof. A variety of the additives are known and commercially available. These additives, or their analogous compounds, can be employed for the preparation of the lubricating oil compositions of the disclosure by the usual blending procedures.

Each of the foregoing additives, when used, is used at a functionally effective amount to impart the desired properties to the lubricant. Thus, for example, if an additive is a friction modifier, a functionally effective amount of this friction modifier would be an amount sufficient to impart the desired friction modifying characteristics to the lubricant.

In general, the concentration of each of the additives in the lubricating oil composition, when used, may range from about <NUM> wt. % to about <NUM> wt. %, from about <NUM> wt. % to about <NUM> wt. %, or from about <NUM> wt. % to about <NUM> wt. %, from about <NUM> wt. % to about <NUM> wt. %, or from about <NUM> wt. % to about <NUM> wt. %, based on the total weight of the lubricating oil composition. Further, the total amount of the additives in the lubricating oil composition may range from about <NUM> wt. % to about <NUM> wt. %, from about <NUM> wt. % to about <NUM> wt. %, or from about <NUM> wt. % to about <NUM> wt. %, based on the total weight of the lubricating oil composition.

The following examples are presented to exemplify embodiments of the disclosure but are not intended to limit the disclosure to the specific embodiments set forth. Unless indicated to the contrary, 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 stated ranges may still fall within the scope of the disclosure. Specific details described in each example should not be construed as necessary features of the disclosure.

It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, 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 present disclosure are for illustration purposes only. Other arrangements and methods may be implemented by those skilled in the art without departing from the scope of this disclosure. Moreover, those skilled in the art will envision other modifications within the scope of the claims appended hereto.

The lubricating oils were evaluated by the Japanese Industrial Standard (JIS) K2246 test that has been slightly modified for hybrid vehicle lubricants. JIS K2246 test involves coating test piece sample with test oil and checking for rusting on the test sample. The modified JIS K2246 test only differs from the standard JIS K2246 test in that the test piece sample is coated with a mixture containing test oil and distilled water. As a result, the modified JIS K2246 test is more appropriate for evaluating the expected rust performance in vehicles susceptible to rust (e.g., hybrid vehicles). Table <NUM> summarizes the modified JIS K2246 test results.

The test piece sample was placed in a humidity cabinet above <NUM>% relative humidity (RH) at <NUM> and allowed to stand for <NUM> hours. The test assessed the ability of oils to prevent rust on metal materials or metal products, mainly consisting of iron and steel.

The ASTM D1748 test (humidity cabinet rust test) was performed in a similar fashion. A lower rust rating indicates better anti-corrosion performance. A rating of <NUM> or lower indicates a pass rating.

The mixture containing test oil and distilled water was prepared according to the following steps:.

A lubricating oil composition was prepared that contained a major amount of a group III base oil of lubricating viscosity and the following additives, to provide a finished oil having a 5W-<NUM> SAE viscosity grade:.

Examples <NUM>-<NUM> were prepared identically as Comparative Example <NUM>, with the addition of <NUM>-<NUM> wt% of an ethoxylated alcohol demulsifier, ethoxylated secondary alcohol, shown in Structure <NUM>. Table <NUM> summarizes the JIS K2246 results. Examples <NUM>-<NUM> containing the additional demulsifier shows improved rust inhibition compared to the baseline formulation.

As is apparent from the foregoing general description and the specific embodiments, while forms of the present disclosure have been illustrated and described, various modifications can be made without departing from the scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby.

For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, within a range includes every point or individual value between its end points even though not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

Likewise, the term "comprising" is considered synonymous with the term "including. " Likewise whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising," it is understood that we also contemplate the same composition or group of elements with transitional phrases "consisting essentially of," "consisting of," "selected from the group of consisting of," or "is" preceding the recitation of the composition, element, or elements and vice versa.

The terms "a" and "the" as used herein are understood to encompass the plural as well as the singular.

The foregoing description of the disclosure illustrates and describes the present disclosure. Additionally, the disclosure shows and describes only the preferred embodiments but, as mentioned above, it is to be understood that the disclosure is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the concept as expressed herein, commensurate with the above teachings and/or the skill or knowledge of the relevant art. While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

It is understood that when combinations, subsets, groups, etc. of elements are disclosed (e.g., combinations of components in a composition, or combinations of steps in a method), that while specific reference of each of the various individual and collective combinations and permutations of these elements may not be explicitly disclosed, each is specifically contemplated and described herein.

Claim 1:
A lubricating oil composition for hybrid vehicles comprising:
a. a major amount of an oil of lubricating viscosity;
b. an ethoxylated alcohol demulsifier of the following formula:

        R<NUM>-(O-R<NUM>)n-OH

wherein R<NUM> is a branched or linear hydrocarbon group having from <NUM> to <NUM> carbon atoms, R<NUM> is a saturated hydrocarbon group having <NUM> carbon atoms, and n is an integer from <NUM> to <NUM>, wherein the ethoxylated alcohol demulsifier is secondary alcohol, and wherein the ethoxylated alcohol demulsifier is present in <NUM> wt% to <NUM> wt% based on total weight of the lubricating oil composition.