Formulating with Functional Polymers for Improved Retained Fuel Economy Performance

This application claims priority to and the benefit of U.S. Ser. No. 63/632,099 filed Apr. 10, 2024.

This disclosure relates to lubricating oil compositions. It more particularly relates to lubricating oil compositions that provide improved friction modification and improvement in fuel economy performance to an internal combustion engine.

Certain items of the patent literature and non-patent technical literature are cited herein, including citation of various tests standard in the automobile engineering and engine lubrication industries. All such items are hereby incorporated by reference in their entirety and for all purposes by such citation.

Fuel economy (FE) has become an increasingly important attribute for formulations as Original Equipment Manufacturers (OEMs) move towards more environmentally friendly vehicles. Many OEMs have Fuel Economy tests in their specifications, and these can be either stand engine tests (such as MB M111FE, PSA EB2FE, or RN K9K) or vehicles on chassis dynamometers (CD) (such as BMW B48 FE, or MB C400). In the vast majority of these tests, candidate oils are to achieve a target FE improvement compared to a reference fluid. More recently, certain OEMs are moving to retained fuel economy testing, where an aged candidate oil needs to demonstrate equivalent fuel economy to a fresh oil reference fluid. Such tests include the VW PV1811 standard tests

Presently, friction modifiers and oil viscometrics are understood in the art to be the primary variables for achieving the required fuel economy, depending on the type of drive cycle used in the test. Corporate Average Fuel Economy (CAFE) and Worldwide Light vehicles Test Cycle (WLTC) standard tests result in the engine spending more time under boundary lubrication regimes, where friction modifiers bring the most benefit. The New European Driving Cycle (NEDC) standard test examines a more hydrodynamic lubrication regime, where oil viscometrics is the most impactful factor. Other additives can impact fuel economy, such as antiwear agents like ZDDP, dispersants and detergents. Negatively, this can be by inhibiting the mode of action of a friction modifier, competing for the engine surface or by bringing a significant viscometric contribution. Positively this can be by accelerating the formation of tribofilms or by sheer thinning, reducing viscosity.

References of interest include US2024-0141156 and U.S. patent application Ser. No. 18/626,652, filed Apr. 4, 2024, claiming priority to U.S. Ser. No. 63/584,675, filed Sep. 22, 2023.

In a first aspect, the present disclosure relates to a composition, such as a lubricating oil composition, comprising:

Such a lubricating oil composition can be one that is substantially free of an organic friction modifying ingredient, for example, a composition can be substantially free of an organic friction modifying ingredient that is a fatty acid ester, such as a glyceryl monoleate ester (GMO).

Lubricating oil compositions in this disclosure that lack an organic friction modifying ingredient can include instead a molybdenum-based friction modifying ingredient, preferably at 150 ppm or less of molybdenum. A lubricating oil composition as disclosed herein may be substantially free of a molybdenum-based friction modifier.

A lubricating oil composition as disclosed herein can be substantially free of both of an organic friction modifying ingredient and a molybdenum-based friction modifier.

Alternatively, a lubricating oil composition as in this disclosure can include both of an organic friction modifying ingredient and a molybdenum-based friction modifying ingredient, preferably at 150 ppm or less of molybdenum.

Additionally or alternatively, a lubricating oil composition as disclosed herein can be one that optionally includes, one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants having a Mn 1600 g/mol or more (alternately 2000 g/mol or more, alternately 2200 g/mol or more). In some preferable embodiments, a lubricating oil composition as disclosed herein does not include a higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant.

Additionally or alternatively, a lubricating oil composition as disclosed herein can be one that optionally includes, one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants having a Mn of less than 1600 g/mol (alternately less than 1200 g/mol, alternately less than 1000 g/mol).

Additionally or alternatively, a lubricating oil composition as disclosed herein can be one that optionally includes: 1) one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants having a Mn of 1600 g/mol or more (alternately 2000 g/mol or more, alternately 2200 g/mol or more), and 2) one or more, borated lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants having a Mn of less than 1600 g/mol (alternately less than 1200 g/mol, alternately less than 1000 g/mol).

In another embodiment, a lubricating oil composition as disclosed herein is one comprising or resulting from the admixing of:

Another lubricating oil composition as disclosed herein is one comprising or resulting from the admixing of:

Another aspect of the present disclosure is a concentrate comprising or resulting from the admixing of:

A further aspect of the present disclosure is a concentrate comprising or resulting from the admixing of:

Another aspect of the present disclosure is a method of making a lubricating oil composition comprising combining:

Another aspect of the present disclosure is a method of lubricating an engine comprising supplying to the engine a lubricating oil composition as described above. Such method preferably further includes providing a fuel to the engine and combusting the fuel in the engine.

Another aspect of the present disclosure is a method of improving fuel economy of an engine during operation comprising supplying to the engine a lubricating oil composition as described above. Such a method preferably further includes providing a fuel to the engine and combusting the fuel in the engine.

Another aspect of the present disclosure is a method of reducing the Average Friction/Traction Coefficient of an engine during operation comprising supplying to the engine a lubricating oil composition as described above. Such a method preferably further includes providing a fuel to the engine and combusting the fuel in the engine.

Preferably the lubricating oil compositions described herein provide an Average Friction/Traction Coefficient (as determined by HFRR as described in the Experimental section below) of 0.174 or less, or 0.170 or less, or 0.165 or less, or 0.160 or less, or 0.155 or less, or 0.150 or less, or 0.145 or less, or 0.140 or less, or 0.135 or less, or 0.130 or less, or 0.125 or less, or 0.120 or less, or 0.115 or less, or 0.110 or less, or 0.100 or less, or 0.095 or less, or 0.090 or less, or 0.085 or less, or 0.080 or less, or 0.075 or less, or 0.070 or less, or 0.065 or less, or 0.060 or less, or 0.055 or less, or 0.050 or less, or 0.045 or less.

Preferably the lubricating oil compositions described herein (containing components (Bi) and or B2, such as containing (B2)) provide a relative torque reduction of 6.5 percent or more, such as 7 percent or more, such as 8% or more, such as 9% or more, such as 10% or more (as compared to reference oil 1 or 2 in Table 4 below when measured at 105° C., 1100 rpm using the Motored Friction Rig test described in the Experimental section below). Reference oil 1 is use as the reference oil when friction modifier (organic or inorganic) is absent, specifically when molybdenum compounds such as molybdenum dialkyldithiocarbamate are absent. Reference oil 2 is use as the reference oil when friction modifier (organic or inorganic) is present, specifically when molybdenum compounds such as molybdenum dialkyldithiocarbamate (dimer and or trimer) are present. Preferably, the lubricating oil compositions also provide a relative torque reduction of equivalent to or higher than reference oil 1 or 2 in Table 4 below when measured at 70° C., 1500 rpm using the Motored Friction Rig test described in the Experimental section below).

Alternately, the lubricating oil compositions described herein provide a relative torque reduction of 2%, or more, such as 3% or more (as compared to reference oil 2 in Table 4 below when measured at 70° C., 1500 rpm using the Motored Friction Rig test described in the Experimental section below) when, Component (132) is present and molybdenum compound is present, and optionally PIBSA-PAM derived from PIB having an Mn over 1600 g/mol (such as 2000 g/mol or more, such as 2100 g/mol or more) is absent.

Alternately, the lubricating oil compositions described herein provide a relative torque reduction of 2%, or more, such as 2.6% or more, such as 3% or more (as compared to reference oil 2 in Table 4 below when measured at 105° C., 1100 rpm using the Motored Friction Rig test described in the Experimental section below) when, Component (B2) is present and molybdenum compound is present, and optionally PIBSA-PAM derived from PIB having an Mn over 1600 g/mol (such as 2000 g/mol or more, such as 2100 g/mol or more) is absent. See Example 5 below.

Alternately, the lubricating oil compositions described herein provide a relative torque reduction of 2.5%, or more, 2.6 or more, such as 3% or more (as compared to reference oil 2 in Table 4 below when measured at 105° C., 1100 rpm using the Motored Friction Rig test described in the Experimental section below) when, Component (132) is present, organic friction modifier is absent (such as glycerolmonooleate is absent) and molybdenum compound is present, and optionally PIBSA-PAM derived from PIB having an Mn over 1600 g/mol (such as 2000 g/mol or more, such as 2100 g/mol or more) is absent. See Example 6 below.

Alternately, the lubricating oil compositions described herein provide a relative torque reduction of 3.8%, or more, such as 4% or more (as compared to reference oil 2 in Table 4 below when measured at 70° C., 1500 rpm using the Motored Friction Rig test described in the Experimental section below) when, Component (B2) is present, organic friction modifier is absent (such as glycerolmonooleate is absent) and molybdenum compound is present, and optionally PIBSA-PAM derived from PIB having an Mn over 1600 g/mol (such as 2000 g/mol or more, such as 2100 g/mol or more) is absent. See Example 6 below.

In these latter three aspects, the engine can be a gasoline engine, and the fuel can be a non-renewable gasoline fuel or a renewable gasoline fuel, or a combination thereof. Or, the engine can be a diesel engine, and the fuel can be a non-renewable diesel fuel or a renewable diesel fuel, or a combination thereof. Or, the engine can be a natural gas engine, and the fuel can be a non-renewable natural gas fuel, a renewable natural gas fuel, or a combination thereof. Or, the engine can be a hydrogen engine, and the fuel can be a renewable hydrogen fuel, a non-renewable hydrogen fuel, or a combination thereof.

For purposes of this specification and all claims to this invention, the following words and expressions, if and when used, have the meanings ascribed below.

For purposes herein, the new numbering scheme for the Periodic Table of the Elements is used as set out in CHEMICAL AND ENGINEERING NEWS, 63(5), 27 (1985), i.e., Alkali metals are group 1 metals (e.g., Li, Na, K, etc.) and Alkaline earth metals are group 2 metals (e.g., Mg, Ca, Ba, etc.).

The term “comprising” or any cognate word specifies the presence of stated features, steps, or integers or components, but does not preclude the presence or addition of one or more other features, steps, integers, components or groups thereof. The expressions “consists of” or “consists essentially of” or cognates may be embraced within “comprises” or cognates, wherein “consists essentially of” permits inclusion of substances not materially affecting the characteristics of the composition to which it applies.

The term “LOC” means lubricating oil composition.

The term “major amount” means more than 50 mass % of a composition, such as more than 60 mass % of a composition, such as more than 70 mass % of a composition, such as from 80 to 99.009 mass % of a composition, such as from 80 to 99.9 from 80 to 99.009 mass % of a composition, of a composition based upon the mass of the composition.

The term “minor amount” means 50 mass % or less of a composition; such as 40 mass % or less of a composition; such as 30 mass % or less of a composition, such as from 20 to 0.001 mass %, such as from 20 to 0.1 mass %, based upon the mass of the composition.

The term “mass %” means mass percent of a component, based upon the mass of the composition as measured in grams, unless otherwise indicated, and is alternately referred to as weight percent (“weight %”, “wt %”, or “% w/w”).

The term “active ingredient” (also referred to as “a.i.” or “A.I.”) refers to additive material that is neither diluent nor solvent. Unless otherwise indicated, amounts herein are described as active ingredient.

The terms “oil-soluble” and “oil-dispersible,” or cognate terms, used herein do not necessarily indicate that the compounds or additives are soluble, dissolvable, miscible, or are capable of being suspended in the oil in all proportions. These do mean, however, that they are, for example, soluble or stably dispersible in oil to an extent sufficient to exert their intended effect in the environment in which the oil is employed. Moreover, the additional incorporation of other additives may also permit incorporation of higher levels of a particular additive, if desired.

The terms “group” and “radical” are used interchangeably herein.

The term “hydrocarbon” means a compound of hydrogen and carbon atoms. A “heteroatom” is an atom other than carbon or hydrogen. When referred to as “hydrocarbons,” particularly as “refined hydrocarbons,” the hydrocarbons may also contain one or more heteroatoms or heteroatom-containing groups (such as halo, especially chloro and fluoro, amino, alkoxyl, mercapto, alkylmercapto, nitro, nitroso, sulfoxy, etc.) in minor amounts (e.g., where the heteroatom(s) do not substantially alter the hydrocarbon properties of the hydrocarbon compound).

The term “hydrocarbyl” means a radical that contains hydrogen and carbon atoms. Preferably, the group consists essentially of, more preferably consists only of, hydrogen and carbon atoms, unless specified otherwise. Preferably, the hydrocarbyl group comprises an aliphatic hydrocarbyl group. The term “hydrocarbyl” includes “alkyl,” “alkenyl,” “alkynyl,” and “aryl” as defined herein. Hydrocarbyl groups may contain one or more atoms/groups other than carbon and hydrogen provided they do not affect the essentially hydrocarbyl nature of the hydrocarbyl group. Those skilled in the art will be aware of such atoms/groups (e.g., halo, especially chloro and fluoro, amino, alkoxyl, mercapto, alkylmercapto, nitro, nitroso, sulfoxy, etc.).

The term “alkyl” means a radical of carbon and hydrogen (such as a Cto C, such as a Cto Cgroup). Alkyl groups in a compound are typically bonded to the compound directly via a carbon atom. Unless otherwise specified, alkyl groups may be linear (i.e., unbranched) or branched, be cyclic, acyclic, or part cyclic/acyclic. Preferably, the alkyl group comprises a linear or branched acyclic alkyl group. Representative examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, neo-pentyl, hexyl, heptyl, octyl, dimethyl hexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl and triacontyl.

The term “alkenyl” means a radical of carbon and hydrogen (such as a Cto Cradical, such as a Cto Cradical) having at least one double bond. Alkenyl groups in a compound are typically bonded to the compound directly via a carbon atom. Unless otherwise specified, alkenyl groups may be linear (i.e., unbranched) or branched, be cyclic, acyclic or part cyclic/acyclic.

The term “alkylene” means a C1 to C, preferably a Cto C, bivalent saturated aliphatic radical, which may be linear or branched. Representative examples of alkylene include methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, 1-methyl ethylene, 1-ethyl ethylene, 1-ethyl-2-methyl ethylene, 1,1-dimethyl ethylene and 1-ethyl propylene.

An “olefin”, alternatively referred to as “alkene,” is a linear, branched, or cyclic compound of carbon and hydrogen having at least one double bond. For purposes of this specification and the Ees appended thereto, when a polymer or copolymer is referred to as comprising an olefin, the olefin present in such polymer or copolymer is the polymerized form of the olefin. For example, when a copolymer is said to have an “isoprene” content of 55 wt % to 95 wt %, it is understood that the mer unit in the copolymer is derived from isoprene in the polymerization reaction and said derived units are present at 55 wt % to 95 wt %, based upon the weight of the copolymer. A “polymer” has two or more of the same or different mer units. A “homopolymer” is a polymer having mer units that are the same. A “copolymer” is a polymer having two or more mer units that are different from each other. “Different” as used to refer to mer units indicates that the mer units differ from each other by at least one atom or are different isomerically. An “isoprene polymer” or “isoprene copolymer” is a polymer or copolymer comprising at least 50 mol % isoprene derived units, a “butadiene polymer” or “butadiene copolymer” is a polymer or copolymer comprising at least 50 mol % butadiene derived units, and so on. Likewise, when a polymer is referred to as a “partially or fully saturated polymer comprising Colefins,” the Colefin(s) present in such polymer or copolymer are the polymerized form of the olefin(s), and the polymer has been partially or fully saturated (such as by hydrogenation) after polymerization of the monomers.

The term “alkynyl” means a Cto C(such as a Cto C) radical, which includes at least one carbon-to-carbon triple bond.

The term “aryl” means a group containing at least one aromatic ring, such a cyclopentadiene, phenyl, naphthyl, anthracenyl, and the like. Aryl groups are typically Cto C(such as Cto C, such as Cto C) aryl groups, optionally substituted by one or more hydrocarbyl groups, heteroatoms, or heteroatom-containing groups (such as halo, hydroxyl, alkoxy and amino groups). Preferred aryl groups include phenyl and naphthyl groups and substituted derivatives thereof, especially phenyl, and alkyl substituted derivatives of phenyl.

The term “substituted” means that a hydrogen atom has been replaced with hydrocarbon group, a heteroatom, or a heteroatom-containing group. An alkyl substituted derivative means a hydrogen atom has been replaced with an alkyl group. An “alkyl substituted phenyl” is a phenyl group where a hydrogen atom has been replaced by an alkyl group, such as a Cto Calkyl group, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, neo-pentyl, hexyl, heptyl, octyl, dimethyl hexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl and/or triacontyl.

The term “halogen” or “halo” means a group 17 atom or a radical of group 17 atom, such as fluoro, chloro, bromo, and iodo.

The term “ashless” in relation to an additive means the composition does not include a metal.