JP2023525328A - Lubricating oil composition containing comb polymethacrylate and ethylene-based olefin copolymer viscosity modifier - Google Patents

Abstract

A lubricating oil composition, e.g., SAE 0W-20, comprising (a) a major amount of an oil of lubricating viscosity, (b) a non-dispersing comb polymethacrylate (PMA), and (c) a non-dispersing ethylene-based olefin copolymer, or lower viscosity grade. Also provided is a method of reducing wear in an internal combustion engine by lubricating the engine with a lubricating oil composition. [Selection figure] None

Description

TECHNICAL FIELD The disclosed technology relates to lubricating oils for internal combustion engines, in particular, lubricating oils for spark ignition engines.

Engine oils are mixed with various additives to meet performance requirements. A challenge in engine oil formulations is to simultaneously achieve wear, deposit and gloss control while also achieving improved fuel economy.

One known method for improving the fuel economy of lubricating oil compositions is to lower the viscosity (ie, high temperature high shear (HTHS) viscosity). HTHS is a measure of the viscosity of a lubricating oil composition under severe engine conditions. However, this approach is reaching the limits of current equipment capabilities and standards. At a given viscosity, the addition of organic or organometallic friction modifiers reduces the surface friction of lubricating oil compositions, allowing for better fuel economy. However, these additives often lead to adverse effects such as increased deposit formation and seal impact, or they overwhelm the anti-wear component in a finite surface area, thereby preventing the formation of a wear-resistant film and reducing wear. cause an increase in

Viscosity modifiers are also widely used to improve the viscosity index (VI) of lubricating oil compositions to thicken the oil with increasing temperature. However, at high temperatures and under high stress conditions, viscosity modifier degradation can occur. When this occurs, the viscosity of the lubricating oil composition decreases, which can lead to increased engine wear.

Accordingly, engine lubricants that provide good fuel economy while also providing excellent antiwear performance, particularly those having a viscosity grade of SAE 0W-20 or lower, have advanced in lubricant formulation technology. However, it continues to be needed.

In one aspect, the present disclosure provides a lubricating oil composition having a 100° C. kinematic viscosity of less than 9.3 mm ² /s, comprising:
a) a major amount of oil of lubricating viscosity;
b) a non-dispersed comb polymethacrylate (PMA); and c) a non-dispersed ethylene-based olefin copolymer.

Another aspect of the present disclosure is a method of reducing wear in an internal combustion engine comprising lubricating the engine with a lubricating oil composition having a 100° C. kinematic viscosity of less than 9.3 mm ² /s, comprising: The composition
a) a major amount of oil of lubricating viscosity;
b) a non-dispersed comb polymethacrylate (PMA); and c) a non-dispersed ethylenic olefin copolymer.

Yet another aspect of the present disclosure is a lubricating oil composition comprising:
a) a major amount of oil of lubricating viscosity;
b) non-dispersed comb polymethacrylate (PMA) in an amount of 0.4% to 1.9% by weight, based on the total weight of the lubricating oil composition; and c), based on the total weight of the lubricating oil composition. as a lubricating oil composition comprising a non-dispersed ethylene-based olefin copolymer in an amount of 0.01% to 0.36% by weight.

Another aspect of the present disclosure is a method of reducing wear in an internal combustion engine comprising lubricating the engine with a lubricating oil composition, wherein the lubricating oil composition comprises:
a) a major amount of oil of lubricating viscosity;
b) non-dispersed comb polymethacrylate (PMA) in an amount of 0.4% to 1.9% by weight, based on the total weight of the lubricating oil composition; and c), based on the total weight of the lubricating oil composition. As a non-dispersed ethylene-based olefin copolymer in an amount of 0.01% to 0.36% by weight.

To facilitate understanding of the subject matter disclosed herein, a number of terms, abbreviations or other abbreviations used herein are defined below. It is understood that any term, abbreviation or shorthand not defined has its ordinary meaning as used by one of ordinary skill in the art contemporaneous with the filing of this application.

Definitions As used herein, the following words and expressions have the meanings indicated below when used.

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

"Minor amount" is expressed in terms of the additive indicated and in terms of the total mass of all additives present in the composition, counting as active ingredient of the additive or additives, 50% by weight of the composition means less than

"Active ingredient" or "active substance" refers to an additive substance that is neither a diluent nor a solvent.

All percentages reported are weight percent (wt %) on an active ingredient basis (ie, not related to carrier or diluent oil), unless otherwise specified.

The abbreviation "ppm" means parts per million by weight based on the total weight of the lubricating oil composition.

100° C. kinematic viscosity (KV) is measured in mm ² /s and determined according to ASTM D445.

150° C. High Temperature High Shear (HTHS) viscosity is determined according to ASTM D4683.

Apparent viscosity at temperatures between -35°C and -5°C is measured by cold cranking simulator according to ASTM D5293.

Metal - The term "metal" refers to alkali metals, alkaline earth metals or mixtures thereof.

Oil soluble or dispersible materials can be incorporated by dissolving, dispersing or suspending in the oil of lubricating viscosity the amount of material required to provide the desired level of activity or performance. means that Generally, this means that at least about 0.001% by weight of the material can be incorporated into the lubricating oil composition. For further discussion regarding the term oil-soluble or dispersible, particularly the term "stable dispersible", see U.S. Pat. invoke.

As used herein, the term "sulphated ash" refers to the non-combustible residue resulting from detergents and metallic additives in lubricating oils. Sulfated ash can be determined according to ASTM D874.

As used herein, the term "total base number" or "TBN" refers to the amount of base equivalent to milligrams of KOH in 1 gram of sample. Therefore, higher TBN numbers reflect more alkaline products and therefore stronger alkalinity. TBN is determined according to ASTM D2896.

Boron, calcium, magnesium, molybdenum, phosphorus, sulfur and zinc contents are determined according to ASTM D5185.

Weight average molecular weight (Mw) and number average molecular weight (Mw) are determined by GPC (gel permeation chromatography) using polystyrene as a standard.

Shear Stability Index (SSI) is measured according to ASTM D7109.

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

Olefins - The term "olefins" refers to a class of unsaturated aliphatic hydrocarbons with one or more carbon-carbon double bonds, obtained by multiple processes. Those containing one double bond are called monoalkenes, those with two double bonds are called dienes, alkyldienes or diolefins. Alpha olefins are particularly reactive because the double bond is between the primary and secondary carbons. Examples are 1-octene and 1-octadecene, which are used as starting points for moderately biodegradable surfactants. Linear and branched olefins are also included in the definition of olefins.

While this disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are described in detail herein. However, the descriptions of specific embodiments herein are not intended to limit the disclosure to the particular forms disclosed, but rather the present invention as defined by the following claims. It is to be understood that the disclosure is intended to cover all modifications, equivalents and alternatives falling within the spirit and scope of the disclosure.

that not all of the activities listed in the general description or examples are required, that some of the specific activities may not be required, and that in addition to those listed Note that one or more further activities may be performed. Moreover, the order in which activities are listed is not necessarily the order in which they are performed.

Benefits, other advantages, and solutions to problems are described herein with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause or make more prominent any benefits, advantages, or solutions to problems may be claimed in any or all of the claims. It should not be construed as an essential, necessary or essential feature.

The specification and illustrations of the embodiments described herein are intended to provide a comprehensive understanding of the structure of various embodiments.

As used herein, "comprises", "comprising", "includes", "including", "has", "has or any other variation thereof is intended to include non-exclusive inclusion. For example, a process, method, article or apparatus that includes recited features is not necessarily limited to those features only, and other features or such processes, methods, articles that are not explicitly recited. Or it may include other features inherent in the device. Further, "or" means inclusively and not exclusively or, except where expressly stated otherwise. For example, condition A or B is satisfied by any one of the following: A is true (or exists) B is false (or does not exist) A is false (or does not exist) ) B is true (or exists) and both A and B are true (or exist).

Use of "a" or "an" are employed to describe elements and components described herein. This is done merely for convenience and to give a general idea of the scope of the embodiments of the disclosure. This description should be read to include one or at least one and the singular also includes the plural and vice versa, unless it is clear that it means otherwise. except for.

The term "on average" when referring to values is intended to mean mean, geometric mean or median. Group numbers corresponding to columns in the periodic table of elements use the "new notation" convention as found in the CRC Handbook of Chemistry and Physics, 81st Edition (2000-2001).

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. Unless stated herein, many details regarding specific materials and treatment practices are conventional and can be found in textbooks and other sources within the lubricant and oil and gas industries.

The specification and illustrations are intended to serve as exhaustive and comprehensive descriptions of all elements and features of formulations, compositions, devices and systems using the structures or methods described herein. do not have. Separate embodiments may be provided in combination as a single embodiment and, conversely, various features that are for simplicity described in the context of a single embodiment may be combined separately or in any part. It may also be offered as a target combination. Further, reference to values stated in ranges include each and every value within that range. Many other embodiments may be apparent to those of skill in the art upon reading this specification. Other embodiments may be used and derived from the present disclosure such that structural, logical, or other changes may be made without departing from the scope of the present disclosure. Accordingly, the present disclosure is to be considered illustrative rather than restrictive.

Oil of Lubricating Viscosity/Base Oil Component An oil of lubricating viscosity (sometimes referred to as a “base stock” or “base oil”) is the major liquid component of a lubricating oil composition, containing additives and optionally is blended with other oils to form, for example, the final lubricating oil composition. Base oils are useful for making concentrates and for making lubricating oil compositions therefrom, and may be selected from natural and synthetic oils, and combinations thereof.

Natural oils include animal and vegetable oils, liquid petroleum oils, and hydrorefined and solvent-treated paraffinic, naphthenic and mixed paraffin-naphthenic mineral lubricating oils. Oils of lubricating viscosity derived from coal or shale are also useful base oils.

Synthetic oils include hydrocarbon oils such as polymeric and copolymerized olefins such as polybutylene, polypropylene, propylene-isobutylene copolymers, chlorinated polybutylenes, poly(1-hexene), poly(1-octene) and poly(1-decene). ); alkylbenzenes (such as dodecylbenzene, tetradecylbenzene, dinonylbenzene and di(2-ethylhexyl)benzene); polyphenols (such as biphenyls, terphenyls, and alkylated polyphenols); and alkylated diphenyl ethers and alkylated diphenyl sulfides. , and derivatives, analogs and homologs thereof).

Another suitable class of synthetic oils are dicarboxylic acids such as malonic, alkylmalonic, alkenylmalonic, succinic, alkyl and alkenylsuccinic acids, maleic acid, fumaric acid, azelaic acid, suberic acid, sebacine acid, adipic acid, linoleic acid dimer, and phthalic acid) with various alcohols such as butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether and propylene glycol. include. Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, Included are dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting 1 mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of 2-ethylhexanoic acid. .

The base oil can be a renewable or bio-derived engine oil. Examples of such engine oils are disclosed in WO2016061050, which is incorporated herein by reference. According to some embodiments, the renewable or bio-derived base oil comprises bio-hydrocarbons, for example isoparaffinic hydrocarbons derived from hydrocarbon terpenes such as myrcene, ocimene and farnesene.

Esters useful as synthetic oils also include those made from _C5 - _C12 monocarboxylic acids and polyols, and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and tripentaerythritol. included.

The base oil may be obtained from hydrocarbons synthesized by the Fischer-Tropsch process. Fischer-Tropsch synthesized hydrocarbons are made from synthesis gas containing H ₂ and CO using a Fischer-Tropsch catalyst. Such hydrocarbons typically require further processing to be useful as base oils. For example, hydrocarbons can be hydroisomerized; hydrocracked and hydroisomerized; dewaxed; or hydroisomerized and dewaxed using processes known to those skilled in the art.

Unrefined, refined and re-refined oils can be used as the base oil in the lubricating oil compositions of this invention. Unrefined oils are oils obtained directly from a natural or synthetic source without further purification treatment. For example, a shale oil obtained directly from retorting operations, a petroleum oil obtained directly from distillation, or an ester oil obtained directly from an esterification process and used without further treatment is an unrefined oil. deaf. Refined oils are similar to unrefined oils, except that they have been further treated in one or more purification steps to improve one or more properties. Many such purification techniques are known to those skilled in the art, such as distillation, solvent extraction, acid or base extraction, filtration and leaching.

Therefore, the base oils that may be used to make the lubricating oil compositions of the present invention are those of Groups IV base oils as defined in the American Petroleum Institute (API) Base Oil Compatibility Code (API Publication 1509). Either can be selected. Such base oil groups are summarized in Table 1 below:

Suitable base oils for use herein are any of the grades corresponding to API Group II, Group III, Group IV and Group V oils, and combinations thereof, preferably with their exceptional volatility , is a Group III to Group V oil due to its characteristics relating to stability, viscosity and cleanliness.

The base oil constitutes the major component of the lubricating oil composition and is present in an amount ranging from greater than 50 wt% to 99 wt% (eg, 70-95 wt%, or 85-95 wt%).

The base oil may be selected from any of the synthetic or natural oils typically used as crankcase lubricants for spark ignited internal combustion engines. Base oils typically have 100° C. kinematic viscosities in the range of 1.5-6 mm ² /s. If the 100° C. kinematic viscosity of the lubricating base oil exceeds 6 mm ² /s, low-temperature viscosity characteristics may deteriorate, and sufficient fuel efficiency may not be obtained. At kinematic viscosities of 1.5 mm ² /s or less, the formation of an oil film at the lubricating location is insufficient, and for this reason the lubricity may be low and the evaporation loss of the lubricating oil composition may increase.

However, in some embodiments a base oil with a kinematic viscosity greater than 6 mm ² /s is required. For example, the base oil as a whole may contain minor proportions of heavier base oils, such as 10 cSt polyalphaolefins.

Preferably, the base oil has a viscosity index of at least 90 (eg at least 95, at least 105, at least 110, at least 115 or at least 120). If the viscosity index is less than 90, not only will the viscosity-temperature properties, thermal and oxidation stability, and volatility resistance decrease, but also the coefficient of friction will tend to increase, and the resistance to abrasion will tend to decrease. will also become

The lubricating oil composition may be a multigrade oil having a viscosity grade of SAE OW-XX, where XX is any one of 8, 10, 12, 16 and 20. According to one preferred embodiment, the lubricating oil composition has a viscosity grade of SAE 0W-20.

The lubricating oil composition has 3.0 cP or less (eg, 1.0 cP to 3.0 cP, or 1.3 cP to 3.0 cP), 2.8 cP or less (eg, 1.0 cP to 2.8 cP, or 1.3 cP ~2.8 cP), 2.7 cP or less (eg, 1.0 cP to 2.7 cP, or 1.3 cP to 2.7 cP), 2.6 cP or less (eg, 1.0 cP to 2.6 cP, or 1.3 cP ~2.6 cP), such as 2.5 cP or less (eg, 1.0 cP to 2.5 cP, or 1.3 cP to 2.5 cP), or 2.0 cP or less (eg, 1.0 cP to 2.0 cP, or 1 .3 cP to 2.0 cP) at 150° C. High Temperature High Shear (HTHS) viscosity. According to exemplary embodiments, the lubricating oil composition has a 150° C. HTHS viscosity of 2.5 cP to 2.6 cP, 2.55 cP to less than 2.9 cP, or 2.55 cP to 2.58 cP.

The lubricating oil composition is at least 135 (eg, 135-400, or 135-250), at least 150 (eg, 150-400, or 150-250), at least 165 (eg, 165-400, or 165-250) , a viscosity index of at least 190 (eg, 190-400, or 190-250), or at least 200 (eg, 200-400, or 200-250). If the viscosity index of the lubricating oil composition is less than 135, it can be difficult to maintain the desired 150° C. HTHS viscosity while improving fuel efficiency. If the viscosity index of the lubricating oil composition is greater than 400, evaporative properties may be degraded and defects may occur due to poor additive solubility and matching properties with the seal material. be. According to exemplary embodiments, the lubricating oil composition has a viscosity index of 200-240, 203-235, 200-210, 220-225, or 230-240.

^{The lubricating oil composition has an _ _} It has a range of 100°C kinematic viscosities. According to exemplary embodiments, the lubricating oil composition has from 6.9 mm ² /s to less than 9.3 mm ² /s, from 7.4 mm 2 /s to 7.8 mm ² /s, 7.45 ^{mm 2} /s ~7.76 mm ² /s, 7.4 mm 2 / ^s ~ 7.5 mm ² /s, 7.5 mm 2 / ^s ~ 7.6 mm 2 /s ^{, 7.6} mm 2 /s ^~ 7.7 mm ² /s, Alternatively, it has a 100° C. kinematic viscosity in the range of 7.7 mm ² /s to 7.8 mm ² /s.

The lubricating oil composition has an apparent viscosity of 3600 mPa·s to 3900 mPa·s at temperatures ranging from 35° C. to −5° C. as measured by a cold cranking simulator (CCS). According to exemplary embodiments, the lubricating oil composition has an apparent viscosity of 3600 mPa·s to 3700 mPa·s, 3700 mPa·s to 3800 mPa·s, or 3800 mPa·s to 3900 mPa·s.

Generally, the sulfur level in the lubricating oil composition is about 0.7 weight percent or less, based on the total weight of the lubricating oil composition. For example, the lubricating oil composition may contain from about 0.01 wt% to 0.5 wt%, 0.01 wt% to 0.4 wt%, 0.01 wt% to 0.3 wt%, 0.01 wt% It may have a sulfur level of ~0.2 wt%, or 0.01 wt% to 0.10 wt%. In one embodiment, the sulfur level in the lubricating oil composition is about 0.60 wt.% or less, about 0.50 wt.% or less, about 0.40 wt.%, based on the total weight of the lubricating oil composition. less than or equal to about 0.30 weight percent, less than or equal to about 0.20 weight percent, or less than or equal to about 0.10 weight percent.

In one embodiment, the level of phosphorus in the lubricating oil composition is no more than about 0.08 wt%, for example from about 0.01 wt% to about 0.08 wt%, based on the total weight of the lubricating oil composition. 08% by weight phosphorus level. In one embodiment, the level of phosphorus in the lubricating oil composition is no more than about 0.07 wt%, for example from about 0.01 wt% to about 0.07 wt%, based on the total weight of the lubricating oil composition. 07% by weight phosphorus level. In one embodiment, the phosphorus level in the lubricating oil composition is no greater than about 0.05 wt%, for example from about 0.01 wt% to about 0.05 wt%, based on the total weight of the lubricating oil composition. 05% by weight phosphorus level.

In one embodiment, the level of sulfated ash produced by the lubricating oil composition is no greater than about 1.00 wt% as determined by ASTM D874, such as about 0.10 wt% as determined by ASTM D874. a sulfated ash level of to about 1.00% by weight. In one embodiment, the level of sulfated ash produced by the lubricating oil composition is no greater than about 0.80 wt% as determined by ASTM D874, such as about 0.10 wt% as determined by ASTM D874. a sulfated ash level of to about 0.80% by weight. In one embodiment, the level of sulfated ash produced by the lubricating oil composition is no greater than about 0.60 wt% as determined by ASTM D874, such as about 0.10 wt% as determined by ASTM D874. a sulfated ash level of to about 0.60% by weight.

Suitably, the lubricating oil composition of the present invention contains 4 to 15 mg KOH/g (such as 5 mg KOH/g to 12 mg KOH/g, 6 mg KOH/g to 12 mg KOH/g, or 8 mg KOH/g to 12 mg KOH/g). KOH/g) total base number (TBN).

Viscosity Modifiers Viscosity modifiers (VM), sometimes referred to as viscosity index improvers (VII), are present in lubricating oil compositions to impart high and low temperature operability. Viscosity modifiers increase the viscosity of the lubricating oil composition at elevated temperatures, thereby increasing film thickness, while having limited impact on low temperature viscosity.

Viscosity modifiers may be used to serve their sole function or may be multifunctional. A multifunctional viscosity modifier can also function as a dispersant.

Examples of suitable viscosity modifiers are polymers and copolymers of methacrylates, butadiene, olefins or alkylated styrenes. Other suitable viscosity modifiers include copolymers of ethylene and propylene, hydrogenated block copolymers of styrene and isoprene, and polyacrylates (eg, copolymers of acrylates of various chain lengths).

Viscosity modifiers may be present in the lubricating oil composition in a total amount of 0.001% to 10% by weight, based on the total weight of the lubricating oil composition. In other embodiments, the viscosity modifier is 0.01 wt% to 8 wt%, 0.1 wt% to 5 wt%, 0.4 wt% to 4 wt%, based on the total weight of the lubricating oil composition. %, 0.6 wt % to 3 wt %, 0.7 wt % to 2 wt %, 1 wt % to 1.5 wt %, or 1.05 wt % to 1.44 wt % . In some exemplary embodiments, the viscosity modifier, based on the total weight of the lubricating oil composition, is 1.0 wt% to 1.2 wt%, 1.3 wt% to 1.4 wt%, or present in a total amount of 1.4% to 1.5% by weight.

Particularly useful in lubricating oil compositions are combinations of non-dispersed comb polymethacrylate (comb PMA) and at least one non-dispersed ethylenic olefin copolymer (OCP).

Non-dispersed Comb Polymethacrylates United States Patent Application 20070010000 Kind Code: A1 Non-dispersed comb polymethacrylates (comb PMA) are comb-shaped polymers and therefore macromolecules in which the main chain has one long branch per repeat unit. is.

In one embodiment, the non-dispersed comb PMA is from 300,000 g/mol to 600,000 g/mol, from 350,000 g/mol to 550,000 g/mol, from 375,000 g/mol to 500,000 g/mol, or It has a weight average molecular weight (Mw) of 390,000 g/mol to 460,000 g/mol.

In one embodiment, the non-dispersed comb PMA is from 35,000 g/mol to 105,000 g/mol, from 45,000 g/mol to 95,000 g/mol, from 55,000 g/mol to 85,000 g/mol, or It has a number average molecular weight (Mn) of 65,000 g/mol to 75,000 g/mol. In another embodiment, the non-dispersed comb PMA has a number average molecular weight (Mn) from 150,000 g/mol to 250,000 g/mol, or from 200,000 g/mol to 215,000 g/mol.

In one embodiment, the non-dispersed comb PMA has a shear stability index (SSI) of 0.1-1.0, 0.2-0.9, or 0.3-0.8.

The non-dispersed comb PMA of the lubricating oil composition may be described as shown in US2017/0298287A1 and JP2019014802, the disclosures of which are incorporated herein by reference. Non-dispersed comb PMA can be provided by Viscoplex® Viscosity Index Improvers 3-201 and/or 3-162, which are available from Evonik.

According to one embodiment, the non-dispersed comb PMA is provided by a compound called Viscoplex® 3-201, which contains comb PMA as the main resin component. This non-dispersed comb PMA has a weight average molecular weight (Mw) of 420,000 g/mol, a number average molecular weight (Mn) of 70,946 g/mol, and a Mw/Mn of 5.92. The compounds have at least structural units derived from macromonomers with Mn of 500 or greater. The non-dispersed comb PMA is present in an amount of 19% by weight, based on the total weight of the compound.

According to another embodiment, the non-dispersed comb PMA is provided by a compound called Viscoplex® 3-162, which also contains comb PMA as the main resin component. This non-dispersed comb PMA has a weight average molecular weight (Mw) of 399,292 g/mol, a number average molecular weight (Mn) of 205,952 g/mol, a Mw/Mn of 1.94, and a shear stable have a sex index (SSI).

According to another embodiment, the non-dispersed comb PMA is provided by a combination of compounds, for example the combination of Viscoplex® 3-201 and Viscoplex® 3-162.

The non-dispersed comb PMA is typically 0.4 wt% to 2.0 wt%, 0.5 wt% to 1.9 wt%, 0.6 wt%, based on the total weight of the lubricating oil composition. Present in an amount from 0.77 wt% to 1.5 wt%, or from 0.76 wt% to 1.33 wt%. According to one embodiment, the non-dispersed comb PMA is present in an amount of 0.4% to 1.9% by weight, based on the total weight of the lubricating oil composition.

Non-dispersing Ethylene-Based Olefin Copolymer The lubricating oil composition also includes a non-dispersing ethylene-based olefin copolymer (OCP) as a viscosity modifier. In one embodiment, the non-dispersed ethylene-based olefin copolymer is of weight average molecular weight (Mw). For example, the non-dispersed ethylene-based olefin copolymer has a weight average It can also have a molecular weight.

In one embodiment, the non-dispersed ethylenic olefin copolymer is from 20,000 g/mol to 100,000 g/mol, from 30,000 g/mol to 90,000 g/mol, or from 35,000 g/mol to 85,000 g/mol with a number average molecular weight (Mn) of

In one embodiment, the nondispersant ethylene-based olefin copolymer has a Shear Stability Index (SSI) of 10-70, 15-65, or 20-60.

Non-dispersed ethylene-based olefin copolymers can be described as follows and as shown in US2013/0203640, the disclosure of which is incorporated herein by reference.

In one embodiment, the non-dispersing ethylenic olefin copolymer is an ethylene propylene copolymer.

In one embodiment, the non-dispersing ethylene-based olefin copolymer has a total ethylene content of 35% to 70%, or 40% to 65% by weight, based on the total weight of the non-dispersing ethylene-based olefin copolymer. have. In another embodiment, the non-dispersing ethylene-based olefin copolymer has a total ethylene content of 45% to 60% by weight, based on the total weight of the non-dispersing ethylene-based olefin copolymer.

The lubricating oil composition may contain more than one non-dispersed ethylene-based olefin copolymer. In one embodiment, the lubricating oil composition comprises a combination of a first ethylene-α-olefin copolymer (a) and a second ethylene-α-olefin copolymer (b). In this case, the lubricating oil composition typically comprises from about 30% to about 70% by weight of the first ethylene-α-olefin copolymer (a) and from about 70% to about 30% by weight of the second ethylene- and an α-olefin copolymer (b), based on the total amount of (a) and (b) in the lubricating oil composition. In another embodiment, the lubricating oil composition comprises from about 40% to about 60% by weight of the first ethylene-α-olefin copolymer (a) and from about 60% to about 40% by weight of the second ethylene-α. - an olefin copolymer (b), based on the total amount of (a) and (b) in the composition. In certain embodiments, the lubricating oil composition comprises from about 50% to about 54% by weight of the first ethylene-α-olefin copolymer (a) and from about 46% to about 50% by weight of the second ethylene-α. - an olefin copolymer (b), based on the total amount of (a) and (b) in the composition.

In one embodiment, the weight average molecular weight of the first ethylene-α-olefin copolymer is typically from about 60,000 g/mol to about 120,000 g/mol. In another embodiment, the weight average molecular weight of the first ethylene-α-olefin copolymer is typically from about 70,000 g/mol to about 110,000 g/mol. In one embodiment, the weight average molecular weight of the second ethylene-α-olefin copolymer is typically from about 60,000 g/mol to about 120,000 g/mol. In another embodiment, the weight average molecular weight of the second ethylene-α-olefin copolymer is typically from about 70,000 g/mol to about 110,000 g/mol. In one embodiment, the weight average molecular weight of the composition of the first ethylene-α-olefin copolymer and the second ethylene-α-olefin copolymer is typically from about 60,000 g/mol to about 120,000 g/mol. be. In another embodiment, the weight average molecular weight of the composition of the first ethylene-α-olefin copolymer and the second ethylene-α-olefin copolymer is typically from about 70,000 g/mol to about 110,000 g/mol is. In further embodiments, the weight average molecular weight of the composition of the first ethylene-α-olefin copolymer and the second ethylene-α-olefin copolymer is typically from about 80,000 g/mol to about 100,000 g/mol. be. The molecular weight distribution of each ethylene-α-olefin copolymer is typically less than about 2.5, more typically from about 2.1 to about 2.4. Polymer distributions determined by GPC are typically unimodal.

The at least one non-dispersed ethylenic olefin copolymer is typically 0.01 wt% to 1.5 wt%, 0.05 wt% to 1.0 wt%, based on the total weight of the lubricating oil composition , 0.08% to 0.4%, 0.1% to 0.5%, or 0.15% to 0.4% by weight. According to one embodiment, the at least one non-dispersed ethylene-based olefin copolymer is present in an amount of 0.01 wt% to 0.36 wt%, based on the total weight of the lubricating oil composition.

Additional Additives In addition to the non-dispersed comb PMA and non-dispersed ethylene-based olefin copolymer viscosity modifiers described above, the lubricating oil compositions of the present disclosure impart or add any desired properties of the lubricating oil composition. It may contain one or more additional performance additives that may improve it. 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 are those described by R.I. M. Mortier et al. "Chemistry and Technology of Lubricants," 3rd Edition, Springer (2010); R. Rudnik, "Lubricant Additives: Chemistry and Applications," Second Edition, CRC Press (2009).

For example, the lubricating oil composition may contain antioxidants, antiwear agents, metal detergents, dispersants, additional friction modifiers, corrosion inhibitors, demulsifiers, additional viscosity modifiers, pour point depressants, demulsifiers. It may contain foaming agents and the like.

Generally, the concentration of each additive in the lubricating oil composition when used is 0.001 wt% to 10 wt% (e.g., 0.01 wt% to 5 wt%) based on the total weight of the lubricating oil composition. %, or range from 0.05% to 2.5%). Further, the total amount of additives in the lubricating oil composition is, based on the total weight of the lubricating oil composition, 0.001 wt% to 20 wt% (eg, 0.01 wt% to 15 wt%, or 0 .1% to 10% by weight).

Antioxidants Antioxidants slow the oxidative deterioration of base oils during service. Such deterioration can cause deposits on metal surfaces, the presence of sludge, or increased viscosity of the lubricating oil composition. Useful antioxidants include hindered phenols, aromatic amines and sulfurized alkylphenols, and alkali and alkaline earth metal salts thereof.

Hindered phenol antioxidants may contain secondary and/or tertiary butyl groups as sterically hindered groups. The phenolic group may be further substituted with a hydrocarbyl group and/or a bridging group linking it to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 2,2′-methylenebis(6-tert-butyl- 4-methylphenol), 4,4′-bis(2,6-di-tert-butylphenol), and 4,4′-methylenebis(2,6-di-tert-butylphenol). Hindered phenol antioxidants can be esters or addition products derived from 2,6-di-tert-butylphenol and alkyl acrylates, where the alkyl groups contain from 1 to 18 carbon atoms. obtain.

Suitable aromatic amine antioxidants include diarylamines such as alkylated diphenylamines (eg, dioctyldiphenylamine, dinonyldiphenylamine), phenyl-alpha-naphthalenes, and alkylated phenyl-alpha-naphthalenes.

According to an exemplary embodiment, the lubricating oil composition comprises an aminic antioxidant.

Antiwear Agents Antiwear agents help reduce wear on metal parts lubricated with the lubricating oil composition. Examples of antiwear agents include phosphorus containing antiwear/extreme pressure agents such as metal thiophosphates, phosphate esters and salts thereof; phosphorus containing carboxylic acids, esters, ethers and amides; and phosphites. The antiwear agent may be zinc dialkyldithiophosphate (ZnDTP). Non-phosphorus containing antiwear agents include borate esters (including borated epoxides), dithiocarbamate compounds, molybdenum containing compounds, and sulfurized olefins.

According to one exemplary embodiment, the lubricating oil composition comprises ZnDTP as an antiwear agent.

Metal Detergents Typical detergents are anionic materials containing a long chain hydrophobic portion of the molecule and a smaller anionic or oleophobic hydrophilic portion of the molecule. The anionic portion of the detergent is typically an organic acid such as sulfuric acid, carboxylic acid, phosphoric acid, phenol or mixtures thereof. Counterions are typically alkaline earth or alkali metal.

In some embodiments, the lubricating oil compositions provided herein comprise at least a neutral or overbased metallic detergent as an additive or additive component. In some embodiments, the metal detergent in the lubricating oil composition acts as a neutralizer for acid products in the lubricating oil composition. In some embodiments, the metal detergent prevents the formation of deposits on the surfaces of the engine. Depending on the nature of the acid used, detergents may have additional functions, such as antioxidant properties. In some embodiments, the lubricating oil composition contains metallic detergents, including either overbased detergents or mixtures of neutral and overbased detergents. The term "overbased" is intended to define an additive containing metals in excess of that required by the stoichiometry of the particular metal and the particular organic acid used. . The excess metal is present in the form of particles of inorganic base (eg hydroxide or carbonate) surrounded by a coating of metal salt. The coating serves to keep the particles dispersed in the liquid oily vehicle. The amount of excess metal is generally expressed as a ratio of total equivalents of excess metal to equivalents of organic acid, typically in the range of 0.1-30.

Some examples of suitable metal detergents include sulfurized or non-sulfurized alkyl or alkenyl phenates, alkyl or alkenyl aromatic sulfonates, borated sulfonates, sulfurized or non-sulfurized metal salts of polyhydroxyalkyl or alkenyl aromatic compounds, Included are alkyl or alkenyl hydroxyaromatic sulfonates, sulfurized or unsulfurized alkyl or alkenyl naphthenates, metal salts of alkanoic acids, metal salts of alkyl or alkenyl polyacids, and chemical and physical mixtures thereof. Other examples of suitable metal detergents include metal sulfonates, phenates, salicylates, phosphonates, thiophosphonates and combinations thereof. The metal can be any metal suitable for making sulfonate, phenate, salicylate or phosphonate detergents. Non-limiting examples of suitable metals include alkali metals, alkaline metals and transition metals. In some embodiments, the metal is Ca, Mg, Ba, K, Na, Li, and the like.

Metal detergents can be overbased detergents, such as low overbased (LOB), medium overbased (MOB) or high overbased (HOB) detergents.

Low overbased detergents can be overbased salts having a base number (BN) of less than 100. In one embodiment, the BN of the low overbased salt can be from about 5 to about 50. In another embodiment, the BN of the low overbased salt can be from about 10 to about 30. In yet another embodiment, the BN of the low overbased salt can be from about 15 to about 20. Base numbers for overbased detergents are measured in the presence of diluent oil rather than on an oil-free basis.

Medium overbased detergents can be overbased salts having a BN of about 100 to about 250. In one embodiment, the BN of the intermediate overbased salt can be from about 100 to about 200. In another embodiment, the BN of the intermediate overbased salt can be from about 125 to about 175. Base numbers for overbased detergents are measured in the presence of diluent oil rather than on an oil-free basis.

A highly overbased detergent can be an overbased salt having a BN greater than 250. In one embodiment, the BN of the highly overbased salt can be from about 250 to about 550. Base numbers for overbased detergents are measured in the presence of diluent oil rather than on an oil-free basis.

Exemplary metal detergents that may be employed in the lubricating oil composition include overbased calcium phenates. According to another exemplary embodiment, the lubricating oil composition comprises LOB Ca sulfonate, HOB Ca salicylate, and MOB Ca salicylate as detergents.

Ashless Dispersants Dispersants are additives whose primary function is to keep solid and liquid contaminants in suspension, thereby passivating them, mitigating sludge settling as well as reducing engine deposits. For example, dispersants maintain in suspension oil-insoluble materials produced by oxidation during use of the lubricating oil composition, thus preventing sludge flocculation and deposition or settling on metal parts of the engine. Typically, dispersants are "ashless", non-metallic organic materials that form substantially no ash upon combustion, unlike materials that contain metals and therefore form ash. They contain a long hydrocarbon chain with a polar head, the polarity being derived from containing at least one nitrogen, oxygen or phosphorous atom. The hydrocarbon is a lipophilic group that confers oil solubility and has, for example, 40 to 500 carbon atoms. Thus, ashless dispersants can include an oil-soluble polymeric backbone.

A preferred class of olefin polymers consists of polybutylenes, specifically polyisobutylene (PIB) or poly-n-butylenes, such as can be prepared by polymerization of C4 refinery streams.

Dispersants include, for example, derivatives of long chain hydrocarbon-substituted carboxylic acids, examples of which are derivatives of high molecular weight hydrocarbyl-substituted succinic acids. A notable group of dispersants is composed of hydrocarbon-substituted succinimides, for example made by reacting the above acids (or derivatives) with a nitrogen-containing compound, conveniently a polyalkylenepolyamine, such as a polyethylenepolyamine. . A typical commercially available polyisobutylene-based succinimide dispersant is polyisobutylene having a number average molecular weight ranging from 900 to 2500 functionalized with maleic anhydride and derivatized with a polyamine having a molecular weight ranging from 100 to 350. Contains polymer.

Other suitable dispersants include succinate esters and ester amides, Mannich bases, polyisobutylene succinate (PIBSA), and other related ingredients.

Succinate esters are formed by condensation reactions between hydrocarbon-substituted succinic anhydrides and alcohols or polyols. For example, condensation products of hydrocarbon-substituted succinic anhydrides and pentaerythritol are useful dispersants.

Succinate ester-amides are formed by condensation reactions between hydrocarbon-substituted succinic anhydrides and alkanolamines. For example, suitable alkanolamines include ethoxylated polyalkylpolyamines, propoxylated polyalkylpolyamines, and polyalkenylpolyamines such as polyethylene polyamines. One example is propoxylated hexamethylenediamine.

Mannich bases are made from the reaction of alkylphenols, formaldehyde and polyalkylenepolyamines. The molecular weight of the alkylphenol can range from 800-2500.

Nitrogen-containing dispersants can be post-treated in a conventional manner to improve their properties by reaction with any of a variety of agents. Included among these are boron compounds (eg boronic acids) and cyclic carbonates (eg ethylene carbonate).

According to one exemplary embodiment, the lubricating oil composition comprises borated succinimide and ethylene carbonate (EC) treated succinimide as ashless dispersants.

Friction Modifiers Lubricating oil compositions may include friction modifiers. A friction modifier is any substance or substances that can change the coefficient of friction of a surface lubricated by any lubricant or fluid containing such substance(s). Friction modifiers include alkoxylated fatty amines, borated fatty epoxides, fatty phosphates, fatty epoxides, fatty amines, borated alkoxylated fatty amines, metal salts of fatty acids, fatty acid amides, glycerol esters, boron Oxidized glycerol esters, and aliphatic imidazolines. As used herein, the term "aliphatic" means a hydrocarbon chain having 10-22 carbon atoms, typically a straight hydrocarbon chain.

According to an exemplary embodiment, the lubricating oil composition comprises organo-molybdenum compounds, also referred to as molybdenum-containing compounds. Organomolybdenum compounds contain at least molybdenum, carbon and hydrogen atoms, but may also contain sulfur, phosphorus, nitrogen and/or oxygen atoms. Suitable organo-molybdenum compounds include molybdenum dithiocarbamates, molybdenum dithiophosphates, and various organo-molybdenum complexes such as molybdenum carboxylates, molybdenum esters, molybdenum amines, molybdenum amides, which are molybdenum oxide or ammonium molybdate. can be obtained by reacting with fats, glycerides or fatty acids or fatty acid derivatives (eg esters, amines and amides). The term "aliphatic" means carbon chains having from 10 to 22 carbon atoms, typically straight carbon chains.

Molybdate esters can be prepared by methods disclosed in US 4,889,647 and US 6,806,241 B2. A commercial example is MOLYVAN® 855 additive, which is available from R.I. T. Vanderbilt Company, Inc. Manufactured by

〔式中、Ｒ^１、Ｒ^２、Ｒ^３、及びＲ^４は互いに独立して、４～１８個の炭素原子（例えば、８～１３個の炭素原子）を有する直鎖または分岐アルキル基である〕
によって表される有機モリブデン化合物である。 According to an exemplary embodiment, the lubricating oil composition comprises molybdenum dithiocarbamate (MoDTC). Molybdenum dithiocarbamate (MoDTC) has the following structure (I):

[wherein R ¹ , R ² , R ³ and R ⁴ are each independently a linear or branched alkyl group having 4 to 18 carbon atoms (eg, 8 to 13 carbon atoms) ]
is an organic molybdenum compound represented by

The preparation of these compounds is well known in the literature and US Pat. Nos. 3,356,702 and 4,098,705, which are incorporated herein by reference. Commercially available examples include R.I. T. Vanderbilt Company Inc. MOLYVAN® 807, MOLYVAN® 822 and MOLYVAN® 2000 manufactured by ADEKA CORPORATION, SAKURA-LUBE® 165 and SAKURA-LUBE® 515 manufactured by ADEKA CORPORATION , as well as Naugalube® MolyFM manufactured by Chemtura Corporation.

Trinuclear molybdenum dialkyldithiocarbamates are also known in the art, as taught by US Pat. Nos. 5,888,945 and 6,010,987, which are incorporated herein by reference. The trinuclear molybdenum compound preferably has the formula _Mo3S4 ( _dtc ) ₄ , _Mo3S7 ( _dtc ) ₄ , and mixtures thereof, where dtc is an independently selected organic group. Represents an independently selected diorganodithiocarbamate ligand containing, the ligand having, among other things, a sufficient number of carbon atoms among the organic groups of the ligand of the compound to render the compound soluble or dispersible in a lubricating oil composition. I am doing something.

〔式中、Ｒ^５、Ｒ^６、Ｒ^７及びＲ^８は互いに独立して、４～１８個の炭素原子（例えば、８～１３個の炭素原子）を有する直鎖または分岐アルキル基である〕
によって表される有機モリブデン化合物である。 According to another embodiment, the lubricating oil composition comprises molybdenum dithiophosphate (MoDTP). MoDTP has the following structure (2):

[wherein R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a linear or branched alkyl group having 4 to 18 carbon atoms (eg, 8 to 13 carbon atoms)]
is an organic molybdenum compound represented by

Molybdenum carboxylates are described in US Pat. No. RE38,929 and US Pat. No. 6,174,842, which are incorporated herein by reference. Molybdenum carboxylates can be derived from any oil-soluble carboxylic acid. Typical carboxylic acids include naphthenic acid, 2-ethylhexanoic acid, and linolenic acid. Commercial sources of carboxylates produced from these particular acids are MOLYBDENUM NAP-ALL, MOLYBDENUM HEX-CEM, and MOLYBDENUM LIN-ALL, respectively. The manufacturer of these products is OMG OM Group.

Ammonium molybdate is optionally treated with an acidic molybdenum source such as molybdenum trioxide, molybdic acid, ammonium molybdate and thiomolybdic acid, optionally in the presence of a sulfur source such as sulfur, inorganic sulfides, polysulfides and carbon disulfide. Prepared by the reaction of ammonium with oil-soluble amines. Preferred amine-based compounds are polyamine dispersants commonly used in engine oil compositions. Examples of such dispersants are succinimides and Mannich-type dispersants. References to these dispersants are in U.S. Pat. Nos. 4,259,194; 4,259,195; Nos. 4,283,295 and 4,285,822.

〔式中、ＲはＣ_２４～Ｃ_３５０（例えば、Ｃ_７０～Ｃ_１２８）アルキルまたはアルケニル基であり、Ｒ’は、２～３個の炭素原子を有する直鎖または分岐鎖アルキレン基であり、ｘは１～１１であり、ｙは１～１０である〕
またはそれらの混合物と反応させることを含むプロセスによって調製される。 In one embodiment, the molybdenum amine is a molybdenum-succinimide complex. Suitable molybdenum-succinimide complexes are described, for example, in US Pat. No. 8,076,275. These complexes convert acidic molybdenum compounds into alkyl or alkenyl succinimides of polyamines of structures (3) and (4):

wherein R is a C ₂₄ -C ₃₅₀ (eg, C ₇₀ -C ₁₂₈ ) alkyl or alkenyl group, R' is a straight or branched chain alkylene group having 2 to 3 carbon atoms, x is 1 to 11 and y is 1 to 10]
or mixtures thereof.

The molybdenum compound used to prepare the molybdenum-succinimide complex is an acidic molybdenum compound or a salt of an acidic molybdenum compound. By "acidic" is meant that the molybdenum compound will react with basic nitrogen compounds as measured by ASTM D664 or D2896. Generally, acidic molybdenum compounds are hexavalent. Representative examples of suitable molybdenum compounds include molybdenum trioxide, molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate and other alkali metal molybdates, as well as other molybdenum salts such as hydrogen salts (e.g. sodium hydrogen molybdate), MoOCl ₄ , MoO ₂ Br ₂ , Mo ₂ O ₃ Cl ₆ and the like.

Succinimides that can be used to prepare molybdenum-succinimide complexes are disclosed in many references and are well known in the art. Some of the basic succinimides and related substances encompassed by the term "succinimide" are described in U.S. Pat. is taught in The term "succinimide" is understood in the art to include many of the amide, imide and amidine species that may be further formed. However, the major product is succinimide, a term generally accepted to mean the product of the reaction of an alkyl- or alkenyl-substituted succinic acid or anhydride with a nitrogen-containing compound. Preferred succinimides are those prepared by reacting polyisobutenyl succinic anhydride having about 70 to 128 carbon atoms with a polyalkylenepolyamine selected from triethylenetetramine, tetraethylenepentamine and mixtures thereof.

In one embodiment, the molybdenum-containing compound is sulfur-free.

Molybdenum-succinimide complexes may be post-treated with a sulfur source at suitable pressures and temperatures not exceeding 120° C. to yield molybdenum sulfide-succinimide complexes. The sulfurization step may be conducted over a period of about 0.5-5 hours (eg, 0.5-2 hours). Suitable sulfur sources include elemental sulfur, hydrogen sulfide, phosphorus pentasulfide, organic polysulfides of formula R ₂ S _x , where R is hydrocarbyl (eg, C ₁ -C ₁₀ alkyl) and x is at least 3 is), C ₁ -C ₁₀ mercaptans, inorganic sulfides and polysulfides, thioacetamides, and thioureas.

The molybdenum-containing compound is used in an amount that provides an amount of molybdenum in the lubricating oil composition of 50 ppm to 1200 ppm, 50 ppm to 1000 ppm, 50 ppm to 800 ppm, 50 ppm to 600 ppm, 50 ppm to 400 ppm, or 50 ppm to 200 ppm.

In some embodiments, the lubricating oil composition is substantially free of molybdenum-containing compounds.

The molybdenum-containing compound may promote the formation of a molybdenum-containing lubricating film on the metal surfaces of the engine during use of the lubricating oil composition in the engine.

According to an exemplary embodiment, the lubricating oil composition comprises MoDTC in an amount of 0.6% to 0.8% by weight, based on the total weight of the lubricating composition.

Corrosion Inhibitors Corrosion inhibitors protect lubricated metal surfaces from chemical attack by water or other contaminants. Suitable corrosion inhibitors include polyoxyalkylene polyols and their esters, polyoxyalkylene phenols, thiadiazoles, and anionic alkyl sulfonic acids.

Pour Point Depressants Pour point depressants lower the minimum temperature at which a fluid will flow or can be poured. Suitable pour point depressants include C8-C18 dialkyl fumarate/vinyl acetate copolymers, polyalkyl methacrylates, and the like.

Foam suppressors Foam suppressors retard the formation of stable foam. Examples of suitable suds suppressors include polysiloxanes, polyacrylates, and the like.

Process for Preparing Lubricating Oil Compositions The lubricating oil compositions disclosed herein may be prepared by any method known to those skilled in the art for making lubricating oils. Viscosity modifiers and other additives may be added to the base oil separately or simultaneously. In some embodiments, additives are added to the base oil individually in one or more additions, and the additions can be in any order. In other embodiments, additives are added to the base oil at the same time, optionally in the form of an additive concentrate. According to another embodiment, some of the additives are added individually and some are added in the form of additive concentrates. In some embodiments, solubilizing the additive in the base oil includes heating the mixture to a temperature of about 25°C to about 200°C, about 50°C to about 150°C, or about 75°C to about 125°C. can be assisted by

Any mixing or dispersing equipment known to those skilled in the art can be used to blend, mix or solubilize the ingredients used to form the lubricating oil composition. Blending, mixing or solubilizing can be performed by compounders, agitators, dispersers, mixers (e.g. planetary mixers and double planetary mixers), homogenizers (e.g. Gorlin homogenizers and Rannie homogenizers), grinders (e.g. , colloid mills, ball mills and sand mills), or any other mixing or dispersing equipment known in the art.

Uses of Lubricating Oil Compositions The lubricating oil compositions disclosed herein may be suitable for use as motor oils (engine oils or crankcase oils) in spark-ignited internal combustion engines. The lubricating oil composition is preferably used in engines or crankcases requiring an SAE 0W-20, 0W-16, or 0W-12 viscosity grade. For example, the lubricating oil composition can be used to lubricate an engine that includes a valve train system with a roller follower rocker arm.

The following examples of the invention are provided to illustrate embodiments of the invention and are not intended to limit the invention to the specific embodiments presented. All parts and percentages are by weight except where indicated to the contrary. All numerical values are approximate. When numerical ranges are given, it should be understood that embodiments deviating from the specified ranges may still fall within the scope of the invention. Specific details described in each example should not be construed as necessary features of the invention.

The baseline formulation for all of the inventive and comparative examples was prepared by blending the following ingredients, provided in weight percent, based on the total weight of the lubricating oil composition:
(a) 1% by weight of borated succinimide,
(b) 3% by weight of ethylene carbonate (EC) treated succinimide;
(c) 0.34% by weight of a second ZnDTP;
(d) 0.72 wt% of a first ZnDTP;
(e) 0.5 wt% LOB Ca sulfonate;
(f) 0.77 wt% HOB Ca salicylate;
(g) 0.5 wt% MOB Ca salicylate;
(h) 2% by weight of an amine antioxidant;
(i) 0.004% by weight of a suds suppressor, and (h) a diluent oil.

The weight percentages of ingredients (a)-(h) include any diluents and/or solvents that may be present and are therefore not based on activity.

All inventive examples and comparative examples were based on a Group III base oil, Yubase 4+, in which the baseline formulation was first treated with 0.7 wt% molybdenum dithiocarbamate (MoDTC) to 700 ppm molybdenum, were made by treating with the viscosity modifier(s) of Tables 2 and 3 (comb PMA and/or OCP) to obtain a lubricating oil composition having a viscosity grade of SAE 0W-20. Compositions of examples of the invention are shown in Table 2, and compositions of comparative examples are shown in Table 3.

Fuel Economy Test in Toyota 2ZR-FE Motor Engine The lubricating oil compositions of Inventive Examples 1-9 and Comparative Examples 1-4 were tested for their fuel economy performance in a gasoline motor engine test. The engine was a Toyota 2ZR-FE 1.8L with an in-line 4-cylinder arrangement. A torque meter was placed between the motor and crankshaft of the engine and the percent torque change was measured between the reference and candidate lubricating oil compositions. The percent torque change was measured at oil temperatures of 60°C, 80°C and 100°C and engine speeds of 400, 550, 750, 1000, 1500 and 2000 rpm. A lower (ie, more negative) percent torque change reflects better fuel economy. The motor engine friction torque test arrangement and its test conditions are further described in SAE Paper 2013-01-2606. Table 4 shows the average % change in torque at oil temperatures of 60°C, 80°C and 100°C for the inventive example compositions and Table 5 shows the 60°C, 80°C for the comparative example compositions. and the average torque change % at an oil temperature of 100°C.

Claims (23)

A lubricating oil composition,
a) a major amount of oil of lubricating viscosity;
b) a non-dispersed comb polymethacrylate (PMA); and c) a non-dispersed ethylene-based olefin copolymer, wherein the lubricating oil composition has a 100° C. kinematic viscosity of less than 9.3 mm ² /s. Composition. The lubricating oil composition of claim 1, wherein said non-dispersed comb PMA has a weight average molecular weight (Mw) of from 390,000 g/mol to 460,000 g/mol. The lubricating oil composition of claim 1, wherein said non-dispersed comb PMA has a Shear Stability Index (SSI) of 0.3 to 0.8. The lubricating oil composition of claim 1, wherein the non-dispersed comb PMA is present in an amount of 0.4 wt% to 2.0 wt%, based on the total weight of the lubricating oil composition. 2. The lubricating oil composition of claim 1, wherein said non-dispersed ethylene-based olefin copolymer has a weight average molecular weight (Mw) of from 90,000 g/mol to 160,000 g/mol. The lubricating oil composition of claim 1, wherein said non-dispersed ethylene-based olefin copolymer has a Shear Stability Index (SSI) of 10-70. The lubricating oil composition of claim 1, wherein said non-dispersed ethylene-based olefin copolymer is present in an amount of 0.08 wt% to 0.4 wt%, based on the total weight of said lubricating oil composition. The lubricating oil composition of claim 1, wherein said non-dispersing ethylene-based olefin copolymer has a total ethylene content of 45% to 60% by weight, based on the total weight of said non-dispersing ethylene-based olefin copolymer. . 2. The lubricating oil composition of claim 1, wherein said non-dispersed ethylenic olefin copolymer is an ethylene propylene copolymer. Based on the total weight of the lubricating oil composition, the non-dispersed comb PMA is present in an amount of 0.76% to 1.33% by weight, and the non-dispersed ethylene-based olefin copolymer is present in an amount of 0.08-1.33% by weight. 2. The lubricating oil composition of claim 1, present in an amount of 0.4% by weight. Claim 1, wherein said non-dispersed comb PMA and said non-dispersed ethylene-based olefin copolymer are present in a total amount of 0.4 wt% to 4 wt%, based on the total weight of said lubricating oil composition. lubricating oil composition. 2. The lubricating oil composition of claim 1, wherein said oil of lubricating viscosity is an API Group III base oil. 2. The lubricating oil composition of claim 1, wherein said composition further comprises a molybdenum compound. 14. The lubricating oil composition of claim 13, wherein said molybdenum compound is molybdenum dithiocarbamate (MoDTC). 14. The lubricating oil composition of claim 13, wherein said molybdenum compound provides said lubricating oil composition with an amount of molybdenum ranging from 50 ppm to 1200 ppm. The lubricating oil composition of claim 1, wherein the lubricating oil composition has a viscosity grade of SAE 0W-20, 0W-16, or 0W-12. The lubricating oil composition of claim 1, wherein said lubricating oil composition has a 150°C high temperature high shear (HTHS) viscosity of less than 2.55 cP to 2.9 cP. The lubricating oil composition of claim 1, wherein said lubricating oil composition has a viscosity index of 200-240. A method of reducing wear in an internal combustion engine comprising:
lubricating said engine with a lubricating oil composition having a 100° C. kinematic viscosity of less than 9.3 mm ² /s, said lubricating oil composition comprising:
a) a major amount of oil of lubricating viscosity;
b) a non-dispersed comb polymethacrylate (PMA); and c) a non-dispersed ethylenic olefin copolymer. 20. The method of claim 19, wherein said engine comprises a roller follower rocker arm. A lubricating oil composition,
a) a major amount of oil of lubricating viscosity;
b) a non-dispersed comb polymethacrylate (PMA) in an amount of 0.4% to 1.9% by weight, based on the total weight of the lubricating oil composition; and c) the total weight of the lubricating oil composition. The lubricating oil composition comprising a non-dispersed ethylene-based olefin copolymer in an amount of 0.01% to 0.36% by weight based on the. A method of reducing wear in an internal combustion engine comprising:
lubricating said engine with a lubricating oil composition, said lubricating oil composition comprising:
a) a major amount of oil of lubricating viscosity;
b) a non-dispersed comb polymethacrylate (PMA) in an amount of 0.4% to 1.9% by weight, based on the total weight of the lubricating oil composition; and c) the total weight of the lubricating oil composition. the non-dispersed ethylenic olefin copolymer in an amount of 0.01% to 0.36% by weight based on the above. 23. The method of claim 22, wherein said engine comprises a roller follower rocker arm.