LUBRICANT COMPOSITIONS COMPRISING OLEFIN COPOLYMER DISPERSANTS IN COMBINATION WITH ADDITIVES

FIELD

The present disclosure relates to lubricants including olefin copolymer dispersants and supplemental lubricant additives to achieve low friction coefficients and good low temperature viscosity characteristics.

BACKGROUND

Friction coefficients are an important characteristic of lubricant compositions. High friction coefficients can be associated with high boundary friction, which is undesirable in certain applications, for example, engine, transmission, axle, and industrial lubricants, because it can negatively impact the wear of the machine parts and the overall machine efficiency. Another important feature of many lubricants is the viscosity at low temperatures. Acceptable low temperature viscosity is required for performance at low temperatures.

Typically low molecular weight friction modifiers are used as the main lever to control the boundary friction of a fluid and viscosity index improvers are used to positively impact the low temperature viscosity characteristics of a fluid. Dispersants, which comprise up to about 50% of an additive package, are not known to have a major impact on either boundary friction or low temperature properties of a lubricant.

Typical dispersants are made by reacting polyisobutylene with maleic anhydride to form a polyisobutylene succinic anhydride (PIBSA). PIBSA is then reacted with amines to form the dispersant. These types of dispersants, when combined with certain additives, tend to have little to no effect in lowering the boundary friction of a lubricant. Some dispersants are formed by reacting an ethylene/propylene copolymer with maleic anhydride to form an ethylene/propylene succinic anhydride (EPSA) which is then reacted with amines to form the dispersant. However, these dispersants can negatively impact the low temperature viscosity of a lubricant.

Accordingly, there is a need for a dispersant, that when combined with certain additives, reduces the friction coefficient of a lubricant that also imparts positive low temperature viscosity characteristics to the fluid.

SUMMARY

The present disclosure relates to lubricant compositions comprising an olefin copolymer dispersant and one or more phosphorus-containing compounds blended in a base oil of lubricating viscosity. The olefin copolymer is derived from ethylene and one or more C₃to C₁₀alpha-olefins and has a number average molecular weight of less than 5,000 g/mol as measured by GPC using polystyrene as a calibration reference. The olefin copolymer has an ethylene monomer moiety content of greater than 40 mol % as measured by ¹H-NMR spectroscopy, a terminal unsaturation of 70 mol % or greater as determined by ¹³C NMR spectroscopy, and at least 70 mol % of the terminal unsaturation is selected from terminal vinylidene, one or more tri-substituted isomers of the terminal vinylidene, and any combination thereof, as measured by ¹H-NMR spectroscopy. Further, the olefin copolymer has an experimental average ethylene run length n_{C2,Experimental}, as determined by ¹³C NMR spectroscopy, of less than 2.6 and also satisfies the relationship:

n
_{C2,Experimental}
<n
_{C2,Statistical} (Equation 6).

The one or more phosphorus-containing compounds may be present in an amount to provide up to 5000 ppm phosphorous to the lubricant composition and may be independently selected from the group consisting of a thiophosphate, a di-thiophosphate, a metal phosphate, a metal thiophosphate, a metal dithiophosphate, a phosphate, a phosphite, a phosphonate, salts thereof, and mixtures thereof.

In each of the foregoing embodiments, the olefin copolymer may have a metal content of 25 ppmw or less, based on the total weight of the copolymer. In each of the foregoing embodiments, the metal content of the olefin copolymer may be the Zr, Ti, Al and B content, derived from a single-site catalyst and an optional co-catalyst. In each of the foregoing embodiments, the olefin copolymer may have a metal content of 10 ppmw or less, or 5 ppmw or less, or 1 ppmw or less, based on the total weight of the copolymer. In any of the foregoing embodiments, the olefin copolymer may have a fluorine content of less than 10 ppmw, or less than 8 ppmw, or less than 5 ppmw, based on the total weight of the copolymer.

In each of the foregoing embodiments, the olefin copolymer dispersant can be obtained by reacting the olefin copolymer with an acylating agent to form an acylated copolymer and reacting the acylated copolymer with a nitrogen source. The acylating agent, for each of the foregoing embodiments, may be maleic anhydride. The nitrogen source, for each of the foregoing embodiments, may be ammonia or a polyalkylene polyamine. The polyalkylene polyamine, for each of the foregoing embodiments, may be a mixture of polyethylene polyamines having an average of 5 nitrogen atoms, triethylene tetramine, tetraethylene pentamine, or combinations thereof.

In each of the foregoing embodiments the olefin copolymer dispersant may be selected from the group consisting of succinimide dispersants, succinic ester dispersants, succinic ester amide dispersants, amide dispersants, ester amide dispersants, or Mannich dispersants. Any of the previously listed olefin copolymer dispersants may be phosphorylated, boronated, maleated, or phosphorylated and borated, or borated and maleated, or phosphorylated and maleated.

In any of the above embodiments, the olefin copolymer may have an ethylene content of at least 49 mol % and less than 80 mol %, or at least 49 mol % and less than 60 mol %. In any of the above embodiments, the one or more C₃to C₁₀alpha-olefins may be selected from the group consisting of propylene, 1-butylene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, or 1-decene. In any of the foregoing embodiments, the one or more C₃to C₁₀alpha-olefin is propylene.

In any of the above embodiments, one or more phosphorus-containing compounds may comprise about 5 to about 20 weight percent phosphorus. In each of the foregoing embodiments, the one or more phosphorus-containing compound(s) may be present in an amount to provide at least 50 ppm, between 300-1500 ppm, up to 600 ppm, or up to 900 ppm phosphorus to the lubricant composition.

In each of the foregoing embodiments, one or more phosphorus-containing compounds may be independently selected from the group consisting of metal phosphate, metal thiophosphate, or metal dithiophosphate. When the one or more phosphorus-containing compounds is metal dithiophosphate, the metal dithiophosphate includes 12 to 32 total carbon atoms within alkyl groups thereon, wherein each of the alkyl groups independently averages between 3 to 8 carbon atoms. When the one or more phosphorus-containing compounds is metal dithiophosphate, at least about 40% of the alkyl groups may be derived from secondary alcohols, or about 100% of the alkyl groups may be derived from secondary alcohols.

When the one or more phosphorus-containing compounds is metal phosphate, metal thiophosphate, or metal dithiophosphate, the metal may be independently selected from the group consisting of aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium, tungsten, zirconium, or zinc. In any of the above embodiments, the metal may be zinc. In each of the foregoing embodiments, the one or more phosphorus-containing compounds may have about 6 to about 10 weight percent phosphorus, about 6 to about 9 weight percent zinc, and about 12 to about 18 weight percent sulfur.

In each of the foregoing embodiments, one or more phosphorus-containing compounds may have the formula:

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wherein R may be independently C₃to C₈alkyl chains so that the total number of carbon atoms is 12 to 32. A may be aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium, tungsten, zirconium, or zinc. In each of these embodiments, R may have at least 40% of the alkyl chains independently derived from secondary alcohols. In each of these embodiments, A may be zinc and R may have about 40% of the alkyl chains independently derived from secondary alcohols, wherein the alkyl chains may have an average of C₄to C₅carbon atoms. In each of the foregoing embodiments, A may be zinc and R may have about 100% of the alkyl chains derived from secondary alcohols, wherein 50% of the alkyl chains may be C₃and 50% of the alkyl chains may be C₆. In each of the foregoing embodiments, A may zinc and R may have about 100% of the alkyl chains derived from secondary alcohols, wherein about 100% of the alkyl chains may be C₆. In each of the foregoing embodiments, A may zinc and R may have about 100% of the alkyl chains derived from primary alcohols, wherein about 100% of the alkyl chains may be C₈.

In each of the foregoing embodiments, the lubricant composition of the present invention may comprise one or more phosphorus-containing compounds of the Formula XIII and the olefin copolymer of the olefin copolymer dispersant may be derived from ethylene and propylene and may have a number average molecular weight of at least about 1300 g/mol, at least about 1390 g/mol, at least about 1600 g/mol, about 1390 g/mol, about 1600 g/mol, about 2700 g/mol, about 1300 g/mol to about 2700 g/mol, or about 1390 g/mol to about 2700 g/mol. In any of these instances, A may be zinc and the phosphorus-containing compound may be present in an amount to provide between 70-800 ppm phosphorus to the lubricant composition.

In each of the foregoing embodiments, the one or more phosphorus-containing compounds may be independently selected from the group consisting of thiophosphate, dithiophosphate, phosphate, phosphite, phosphonate, salts thereof, and mixtures thereof. The phosphorus-containing compounds may be further independently selected from the group consisting of dialkyl dithiophosphate ester, amyl acid phosphate, diamyl acid phosphate, dibutyl hydrogen phosphonate, and dimethyl octadecyl phosphonate, salts thereof, and mixtures thereof.

In each of the foregoing embodiments, the one or more phosphorus-containing compounds has the formula:

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wherein R₁may be S, or O, R₂may be —OR″, —OH, or —R″, R₃may be —OR″, —OH, H, or SR′″C(O)OH, R₄may be —OR″, R″″ may be C₁to C₃branched or linear alkyl chain, and R″ may be a C₁to C₁₈hydrocarbyl chain.

In each of the foregoing embodiments, when the lubricant composition contains the one or more phosphorus-containing compounds of Formula XIV, the one or more phosphorus-containing compounds may be present in an amount to provide about 80 to about 4500 ppm phosphorus to the lubricant composition. In each of the foregoing embodiments, when the lubricant composition contains the one or more phosphorus-containing compounds of Formula XIV, the one or more phosphorus-containing compounds may comprise about 8 to about 16 weight percent phosphorus.

In any of the above embodiments, the lubricant composition comprises the one or more phosphorus-containing compounds of Formula XIV wherein R₁may be S, R₂may be —OR″, R₃may be SR′″C(O)OH, R₄may be OR″, R′″ may be C₃branched alkyl chain, R″ may be C₄, and the one or more phosphorus-containing compounds may be present in an amount to deliver between 180-900 ppm phosphorus to the lubricating composition. In each of the embodiments, R₁may be O, R₂may be —OH, R₃may be —OR″ or —OH, R₄may be —OR″, R″ may be C₅, and the one or more phosphorus-containing compounds may be present in an amount to deliver between 150-1500 ppm phosphorus to the lubricating composition. In each of the foregoing embodiments, R₁may be O, R₂may be —OR″, R₃may be H, R₄may be —OR″, R″ may be C₄, and the one or more phosphorus-containing compounds may be present in an amount to deliver between 300-1550 ppm phosphorus to the lubricating composition. In each of the forgoing embodiments, R₁may be O, R₂may be —R″, R₃may be —OCH₃or —OH, R₄may be —OCH₃, R″ may be C₁₈, and the one or more phosphorus-containing compounds may be present in an amount to deliver between 80-850 ppm phosphorus to the lubricating composition.

The lubricant composition of the present invention may comprise one or more phosphorus-containing compounds of the Formula XIV and the olefin copolymer of the olefin copolymer dispersant may be derived from ethylene and propylene and may have a number average molecular weight of at least 1300 g/mol, at least about 1390 g/mol, at least about 1600 g/mol, about 1390 g/mol, about 1600 g/mol, about 2700 g/mol, about 1300 g/mol to about 2700 g/mol, or about 1390 g/mol to about 2700 g/mol. In any of the foregoing embodiments, the phosphorus-containing compound may be present in an amount to provide between 300-1500 ppm phosphorus to the lubricant composition.

In each of the foregoing embodiments the olefin copolymer dispersant may be present in an amount from about 1 weight percent to about 15 weight percent, or to about 8 weight percent, or to about 4 weight percent, based on the lubricating composition.

In each of the foregoing embodiments the olefin copolymer dispersant may have a formula selected from Formula V, Formula VI, and Formula VII, or mixtures thereof:

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wherein R₅may be a hydrocarbyl radical obtained from the olefin copolymer derived from ethylene and one or more C₃-C₁₀alpha-olefins, R₆may be a divalent C₁-C₆alkylene, R₇may be a divalent C₁-C₆alkylene, each of R₈and R₉, independently, may be H, C₁-C₆alkyl,

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or, together with the N to which they are attached to, form a 5- or 6-membered ring, optionally fused with an aromatic or non-aromatic ring, R₁₀is H; R₁₁may be H or C₁-C₆alkyl, or —CH₂—(NH—R₇)_n—NR₈R₉, W may be a covalent bond or C(O), n may be 0, 1, 2, 3, 4, 5, 6, 7, or 8, and y+z=1. In any of the foregoing embodiments, when y=1, R₅may be C₁₂to C₃₀. In any of the foregoing embodiments, when y=1, R₅may be C₂₀to C₃₀.

In each of the foregoing embodiments, the olefin copolymer dispersant may be selected from Formula V and R₈and R₉together with the N to which they are attached form

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In each of the foregoing embodiments, the olefin copolymer dispersant may be selected from Formula V and R₈and R₉together with the N to which they are attached to, form a 5- or 6-membered ring, fused with an aromatic ring of having the following formula

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In each of the above embodiments, the olefin copolymer dispersant may be post-treated with boric acid and/or maleic anhydride.

In each of the above embodiments, the lubricant composition may also include a base oil of lubricating viscosity selected from a mineral oil, an animal oil, a vegetable oil, a synthetic oil, and mixtures thereof. In each of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than about 120, and a kinematic viscosity at 100° C. from about 2 to about 8 cSt. In each of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than 120, and a kinematic viscosity at 100° C. of about 4 cSt. In each of the foregoing embodiments, the base oil of lubricating viscosity may comprise C_P(paraffinic carbon content) of greater than 55%, C_A(aromatic carbon content) of less than 1%, and C_N(naphthenic carbon content) of greater than 30%, and a ratio of 1 ring naphthenes to 2-6 ring naphthenes of less than 1.5.

In each of the foregoing embodiments, the lubricant composition may include an olefin copolymer dispersant described herein and a zinc dithiophosphate. The olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. The ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The zinc dithiophosphate may deliver between 100 ppm and 1500 ppm phosphorus to the fluid. In each of the foregoing embodiments, at least 40% of the alkyl chains on the zinc dithiophosphate may be derived from secondary alcohols.

In one embodiment, the lubricant composition may include an olefin copolymer dispersant described herein and a zinc dialkyl dithiophosphate. In this embodiment, the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. In this embodiment, the ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. In this embodiment, the olefin copolymer may have a metal content of 10 ppmw or less based on the total weight of the copolymer. In this embodiment, the olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The zinc dialkyl dithiophosphate may deliver between 100 ppm and 1500 ppm phosphorus to the fluid. In this embodiment, at least 40% of the alkyl chains on the zinc dialkyl dithiophosphate may be derived from secondary alcohols.

In each of the foregoing embodiments the lubricant composition may include an olefin copolymer dispersant described herein and one or more phosphorus-containing compound(s) independently selected from the group consisting of dialkyl dithiophosphate ester, amyl acid phosphate, diamyl acid phosphate, dibutyl hydrogen phosphonate, dimethyl octadecyl phosphonate, salts thereof, and mixtures thereof. The olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. The ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more phosphorus-containing compound(s) may deliver between 100 ppm and 1500 ppm phosphorus to the fluid.

In one embodiment, the lubricant composition may include an olefin copolymer dispersant described herein and one or more phosphorus-containing compound(s) independently selected from the group consisting of dialkyl dithiophosphate ester, amyl acid phosphate, diamyl acid phosphate, dibutyl hydrogen phosphonate, dimethyl octadecyl phosphonate, salts thereof, and mixtures thereof. In this embodiment, the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. In this embodiment, the ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. In this embodiment, the olefin copolymer may have a metal content of 10 ppmw or less based on the total weight of the copolymer. In this embodiment, the olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more phosphorus-containing compound(s) may deliver between 100 ppm and 1500 ppm phosphorus to the fluid.

The present disclosure also relates to lubricant compositions comprising an olefin copolymer dispersant and one or more detergent(s) blended in a base oil of lubricating viscosity. The olefin copolymer is derived from ethylene and one or more C₃to C₁₀alpha-olefins and has a number average molecular weight of less than 5,000 g/mol as measured by GPC using polystyrene as a calibration reference. The olefin copolymer has an ethylene monomer moiety content of greater than 40 mol % as measured by ¹H-NMR spectroscopy, a terminal unsaturation of 70 mol % or greater as determined by ¹³C NMR spectroscopy, and at least 70 mol % of the terminal unsaturation is selected from terminal vinylidene, one or more tri-substituted isomers of the terminal vinylidene, and any combination thereof, as measured by ¹H-NMR spectroscopy. Further, the olefin copolymer has an experimental average ethylene run length n_{C2,Experimental}, as determined by ¹³C NMR spectroscopy, of less than 2.6 and also satisfies the relationship:

n
_{C2,Experimental}
<n
_{C2,Statistical} (Equation 6).

In each of the foregoing embodiments, the one or more detergent(s) may be independently selected from the group consisting of a sulfonate, a phenate, a salicylate, a salixrate, a saligenin and mixtures thereof. In each of the foregoing embodiments, the detergent may be independently selected from the group consisting of calcium sulfonate, calcium phenate, magnesium sulfonate, calcium salicylate, and mixtures thereof.

In each of the foregoing embodiments, the lubricant composition comprises one or more detergent(s) and the olefin copolymer dispersant wherein the dispersant can be obtained by reacting the olefin copolymer with an acylating agent to form an acylated copolymer and reacting the acylated copolymer with a nitrogen source. The acylating agent, for each of the foregoing embodiments, may be maleic anhydride. The nitrogen source, for each of the foregoing embodiments, may be ammonia or a polyalkylene polyamine. The polyalkylene polyamine may be selected from the group consisting of a mixture of polyethylene polyamines having an average of 5 nitrogen atoms, triethylenetetramine, tetraethylenepentamine, and combinations thereof.

In each of the foregoing embodiments, the lubricant composition comprises one or more detergent(s) and the olefin copolymer dispersant wherein the dispersant may be selected from the group consisting of succinimide dispersants, succinic ester dispersants, succinic ester amide dispersants, amide dispersants, ester amide dispersants, and Mannich dispersants. Any of the previously listed olefin copolymer dispersants may be phosphorylated, boronated, maleated, or phosphorylated and borated, or borated and maleated, or phosphorylated and maleated.

In each of the above embodiments, the olefin copolymer may have an ethylene content of at least 49 mol % and less than 80 mol %, or less than 60 mol %. In each of the above embodiments, the one or more C₃to C₁₀alpha-olefins may be selected from the group consisting of propylene, 1-butylene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. In each of the foregoing embodiments, the one or more C₃to C₁₀alpha-olefin may be propylene.

In each of the foregoing embodiments, the one or more detergent(s) may be present in the lubricating composition to deliver up to about 12.0 TBN, or between 0.1 TBN and 12 TBN, or between 0.5 TBN and about 8 TBN, or between 3.0 TBN and about 12 TBN to the lubricant composition.

In each of the foregoing embodiments, the one or more detergent(s) may be present in an amount to deliver between 0.1 TBN and 12.0 TBN to the lubricant composition and the olefin copolymer dispersant may be present in an amount to deliver about 180 ppm to about 1500 ppm nitrogen to the lubricant composition. In each of the foregoing embodiments, the lubricant composition may include the one or more detergent(s) in an amount to deliver between about 0.4 TBN to about 8.0 TBN to the lubricant composition and the olefin copolymer dispersant may be present in an amount to deliver about 700 ppm to about 1500 ppm nitrogen to the lubricant composition. In each of the foregoing embodiments, the lubricant composition may include the one or more detergent(s) in an amount to deliver between about 3.0 TBN to about 12.0 TBN to the lubricant composition and the olefin copolymer dispersant may be present in an amount to deliver 700 ppm to about 1500 ppm nitrogen to the lubricant composition. In each of the foregoing embodiments, the lubricant composition may include the one or more detergent(s) in an amount to deliver between about 3.0 TBN to about 7.5 TBN to the lubricant composition and the olefin copolymer dispersant may be present in an amount to deliver 700 ppm to about 800 ppm nitrogen to the lubricant composition.

In each of the foregoing embodiments, the lubricant composition may include the one or more detergent(s) and the olefin copolymer dispersant present at in an amount to deliver between approximately 180 ppm to approximately 1500 ppm of nitrogen to the lubricant composition. In each of the foregoing embodiments, the lubricant composition may include one or more detergent(s) may include the one or more detergent(s) and the olefin copolymer dispersant at an amount to deliver approximately 720 ppm nitrogen to the lubricant composition. In each of the foregoing embodiments, the one or more detergent(s) may be present at an amount to deliver about 3.0 TBN to about 12.0 TBN to the lubricant composition and the olefin copolymer dispersant may be present in an amount to deliver 720 ppm nitrogen to the lubricant composition.

In each of the foregoing embodiments, the one or more detergent(s) may include a metal independently selected from the group consisting of calcium, magnesium, and sodium. In each of the foregoing embodiments, the one or more detergent(s) detergent may comprise a metal independently selected from the group consisting of calcium and magnesium.

In each of the foregoing embodiments, the one or more detergent(s) may be present in an amount to deliver at least 0.3 TBN to the lubricant composition. In each of the foregoing embodiments, the one or more detergent(s) may be present in an amount to deliver between about 0.5 TBN and about 7.5 TBN to the lubricant composition. In each of the foregoing embodiments, the one or more detergent(s) may be present in an amount to deliver at between about 3.0 TBN and about 7.5 TBN to the lubricant composition.

In each of the foregoing embodiments, when the lubricant composition comprises one or more detergent(s), the olefin copolymer dispersant may be present in an amount to deliver up to about 1440 ppm nitrogen to the fluid and the one or more detergent(s) may be present in an amount to deliver at least 0.3 TBN to the fluid. In each of the foregoing embodiments, the olefin copolymer dispersant may be present in an amount to deliver up to about 800 ppm nitrogen to the fluid and the one or more detergent(s) may be present in an amount to deliver at least 4.5 TBN to the fluid.

In each of the foregoing embodiments, the lubricant composition may contain a detergent and the olefin copolymer dispersant wherein the olefin copolymer may be derived from ethylene and propylene and may have a number average molecular weight of at least 1300 g/mol, at least about 1390 g/mol, at least about 1600 g/mol, about 1390 g/mol, about 1600 g/mol, about 2700 g/mol, about 1300 g/mol to about 2700 g/mol, or about 1390 g/mol to about 2700 g/mol.

In each of the foregoing embodiments, the one or more detergent(s) may be independently selected from the group consisting of a 300 TBN calcium sulfonate, 250 TBN calcium phenate, 400 TBN magnesium sulfonate, 165 TBN calcium salicylate, and a 28 TBN calcium sulfonate and the olefin copolymer may be derived from ethylene and one or more C₃to C₁₀alpha-olefins, wherein the one or more C₃to C₁₀alpha-olefins may be propylene and the olefin copolymer may have a number average molecular weight of at least about 1300 g/mol to about 2700 g/mol.

In each of the foregoing embodiments, the lubricant composition may contain the one or more detergent(s) and the olefin copolymer dispersant may have a formula selected from Formula V, Formula VI, and Formula VII, and mixtures thereof:

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wherein R₅may be a hydrocarbyl radical obtained from the olefin copolymer derived from ethylene and one or more C₃-C₁₀alpha-olefins; R₆may be a divalent C₁-C₆alkylene; R₇may be a divalent C₁-C₆alkylene; each of R₈and R₉, independently, may be H, C₁-C₆alkyl,

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or, together with the N to which they are attached to, form a 5- or 6-membered ring, optionally fused with an aromatic or non-aromatic ring; R₁₀is H; R₁₁may be H or C₁-C₆alkyl, or —CH₂—(NH—R₇)_n—NR₈R₉; W may be a covalent bond or C(O); and n may be 0, 1, 2, 3, 4, 5, 6, 7, or 8; and y+z=1. In each of the foregoing embodiments, when y=1, R₅may be C₁₂to C₃₀. In each of the foregoing embodiments, when y=1, R₅may be C₂₀to C₃₀.

In each of the foregoing embodiments, the lubricant composition may comprise one or more detergent(s) and the olefin copolymer dispersant may be selected from Formula V and wherein R₈and R₉together with the N to which they are attached, may form

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In each of the foregoing embodiments, the olefin copolymer dispersant may be selected from Formula V and wherein R₈and R₉together with the N to which they are attached, may form a 5- or 6-membered ring, fused with an aromatic ring of having the following formula

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In each of the foregoing embodiments, the lubricant composition may comprise one or more detergent(s) and the olefin copolymer dispersant, wherein the dispersant may be post-treated with boric acid and/or maleic anhydride.

In each of the foregoing embodiments, the lubricant composition may include the olefin copolymer dispersant, one or more detergent(s) and a base oil of lubricating viscosity selected from a mineral oil, an animal oil, a vegetable oil, a synthetic oil, and mixtures thereof. In each of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than about 120, and a kinematic viscosity at 100° C. from about 2 to about 8 cSt. In each of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than 120, and a kinematic viscosity at 100° C. of about 4 cSt. In each of the foregoing embodiments, the base oil of lubricating viscosity may comprise C_P(paraffinic carbon content) of greater than 55%, C_A(aromatic carbon content) of less than 1%, and C_N(naphthenic carbon content) of greater than 30%; and a ratio of 1 ring naphthenes to 2-6 ring naphthenes of less than 1.5

In each of the foregoing embodiments, the lubricant composition may include an olefin copolymer dispersant and one or more detergent(s), wherein the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. The ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more detergent(s) may deliver between about 0.5 TBN and about 7.5 TBN to the lubricant composition and the olefin copolymer dispersant may deliver at least 700 ppm nitrogen to the lubricant composition.

In one embodiment, the lubricant composition may include an olefin copolymer dispersant and one or more detergent(s), wherein the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. In this embodiment, the ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. In this embodiment, the olefin copolymer may have a metal content of 10 ppmw or less based on the total weight of the copolymer. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more detergent(s) may deliver between about 0.5 TBN and about 7.5 TBN to the lubricant composition and the olefin copolymer dispersant may deliver at least 700 ppm nitrogen to the lubricant composition.

The present disclosure also relates to lubricant compositions comprising the olefin copolymer dispersant and one or more extreme pressure agent(s) blended in a base oil of lubricating viscosity. The olefin copolymer is derived from ethylene and one or more C₃to C₁₀alpha-olefins and has a number average molecular weight of less than 5,000 g/mol as measured by GPC using polystyrene as a calibration reference. The olefin copolymer has an ethylene monomer moiety content of greater than 40 mol % as measured by ¹H-NMR spectroscopy, a terminal unsaturation of 70 mol % or greater as determined by ¹³C NMR spectroscopy, and at least 70 mol % of the terminal unsaturation selected from terminal vinylidene, one or more tri-substituted isomers of the terminal vinylidene, and any combination thereof, as measured by ¹H-NMR spectroscopy. Further, the olefin copolymer has an experimental average ethylene run length n_{C2,Experimental}, as determined by ¹³C NMR spectroscopy, of less than 2.6 and also satisfies the relationship:

n
_{C2,Experimental}
<n
_{C2,Statistical} (Equation 6).

The one or more extreme pressure agent(s) may be independently selected from the group consisting of a sulfurized olefin, a sulfurized animal fat or fatty acid esters, a sulfurized vegetable fat or fatty acid esters, a thiadiazole, a sulfurized isobutylene, a dihydrocarbyl polysulfide, a sulfur-containing amino heterocyclic compound, and mixtures thereof. In of each of the foregoing embodiments, the one or more extreme pressure agent(s) may be independently selected from the group consisting of sulfurized olefin, sulfurized isobutylene, 2,5-dimercapto-1,3,4-thiadiazole, a mixture of polysulfides having a majority of S₃and S₄sulfides, and mixtures thereof.

In each of the foregoing embodiments, the lubricant composition may comprise one or more extreme pressure agent(s) and the olefin copolymer dispersant wherein the dispersant may be obtained by reacting the olefin copolymer with an acylating agent to form an acylated copolymer and reacting the acylated copolymer with a nitrogen source. The acylating agent, for each of the foregoing embodiments, may be maleic anhydride. The nitrogen source, for each of the foregoing embodiments, may be ammonia or a polyalkylene polyamine. The polyalkylene polyamine, for each of the foregoing embodiments, may be a mixture of polyethylene polyamines having an average of 5 nitrogen atoms, triethylene tetramine, tetraethylene pentamine, or combinations thereof.

In each of the foregoing embodiments, the lubricant composition may comprise one or more extreme pressure agent(s) and olefin copolymer dispersant may be selected from the group consisting of succinimide dispersants, succinic ester dispersants, succinic ester amide dispersants, amide dispersants, ester amide dispersants, and Mannich dispersants. Any of the previously listed olefin copolymer dispersants comprising an olefin copolymer may be phosphorylated, boronated, or phosphorylated and borated.

In any of the above embodiments, the olefin copolymer may have an ethylene content of at least 49 mol % and less than 80 mol %, or less than 60 mol %. In any of the above embodiments, the one or more C₃to C₁₀alpha-olefins may be selected from the group consisting of propylene, 1-butylene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. In any of the foregoing embodiments, the one or more C₃to C₁₀alpha-olefin may be propylene.

In any of the foregoing embodiments, the one or more extreme pressure agent(s) may be present in an amount to deliver up to 10,500 ppm sulfur to the lubricant composition. In any of the foregoing embodiments, the one or more extreme pressure agent(s) may be present in an amount to deliver between 100 ppm sulfur and 4800 ppm sulfur to the lubricant composition. In any of the foregoing embodiments, the one or more extreme pressure agent(s) may be present in an amount to deliver between about 350 ppm sulfur and 4600 ppm sulfur to the lubricant composition. In any of the foregoing embodiments, the one or more extreme pressure agent(s) may be present in an amount to deliver between about 350 ppm sulfur and 3500 ppm sulfur to the lubricant composition. In any of the foregoing embodiments, the one or more extreme pressure agent(s) may be present in an amount to deliver between about 350 ppm sulfur and 800 ppm sulfur to the lubricant composition.

In any of the foregoing embodiments, the one or more extreme pressure agent(s) may be present in an amount to deliver about 350 to about 10,500 ppm sulfur to the lubricant composition and the olefin copolymer dispersant may be present in an amount to deliver between about 180 ppm nitrogen to about 1440 ppm nitrogen to the lubricant composition. In any of the foregoing embodiments, the one or more extreme pressure agent(s) may be present in an amount to deliver about 760 ppm to about 4,800 ppm sulfur to the lubricant composition and the olefin copolymer dispersant may be present in an amount to deliver between about 180 ppm nitrogen to about 720 ppm nitrogen to the lubricant composition.

In any of the foregoing embodiments, the one or more extreme pressure agent(s) is present in an amount to deliver at least 350 ppm sulfur to the lubricant composition and the olefin copolymer dispersant may be present in an amount to deliver at least 180 ppm nitrogen to the lubricant composition. In any of the foregoing embodiments, the one or more extreme pressure agent(s) may deliver between about 125 ppm may be present in an amount to deliver between about 720 ppm nitrogen and about 14,400 ppm nitrogen to the lubricant composition. In any of the foregoing embodiments, the one or more extreme pressure agent(s) may deliver between about 750 ppm sulfur and about 5,000 ppm sulfur to the lubricant composition and the olefin copolymer dispersant may be present in an amount to deliver between about 720 ppm nitrogen to the lubricant composition.

In any of the foregoing embodiments, the lubricant composition may contain one or more extreme pressure agent(s) and the olefin copolymer dispersant wherein the olefin copolymer may be derived from ethylene and propylene and may have a number average molecular weight of at least 1300 g/mol, at least about 1390 g/mol, at least about 1600 g/mol, about 1390 g/mol, about 1600 g/mol, about 2700 g/mol, about 1300 g/mol to about 2700 g/mol, or about 1390 g/mol to about 2700 g/mol.

In any of the foregoing embodiments, the one or more extreme pressure agent(s) may be independently selected from the group consisting of a sulfurized olefin, a 2,5-dimercapto-1,3,4-thiadiazole, a sulfurized isobutylene, a mixture of polysulfides having a majority of S₃and S₄sulfides, and mixtures thereof, and the olefin copolymer may be derived from ethylene and one or more C₃to C₁₀alpha-olefins, wherein the one or more C₃to C₁₀alpha-olefins may be propylene and the olefin copolymer may have a number average molecular weight of about 1300 g/mol to about 2700 g/mol.

In any of the foregoing embodiments, the lubricant composition may contain one or more extreme pressure agent(s) and the olefin copolymer dispersant may have a formula selected from Formula V, Formula VI, and Formula VII, and mixtures thereof:

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or, together with the N to which they are attached to, form a 5- or 6-membered ring, optionally fused with an aromatic or non-aromatic ring; R₁₀may be H; R₁₁may be H or C₁-C₆alkyl, or —CH₂—(NH—R₇)_n—NR₈R₉; W may be a covalent bond or C(O); and n may be 0, 1, 2, 3, 4, 5, 6, 7, or 8; and y+z=1. In one embodiment, when y=1, R₅may be C₁₂to C₃₀. In another embodiment, when y=1, R₅may be C₂₀to C₃₀.

In any of the foregoing embodiments, the lubricant composition may contain one or more extreme pressure agent(s) and the olefin copolymer dispersant of Formula V above, wherein R₈and R₉together with the N to which they are attached form

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In any of the foregoing embodiments, the olefin copolymer dispersant may be post-treated with boric acid and/or maleic anhydride.

In any of the foregoing embodiments, the lubricant composition includes the olefin copolymer dispersant, one or more extreme pressure agent(s), and a base oil of lubricating viscosity selected from a mineral oil, an animal oil, a vegetable oil, a synthetic oil, and mixtures thereof. In any of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than about 120, and a kinematic viscosity at 100° C. from about 2 to about 8 cSt. In any of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than 120, and a kinematic viscosity at 100° C. of about 4 cSt. In any of the foregoing embodiments, the base oil of lubricating viscosity may comprise C_P(paraffinic carbon content) of greater than 55%, C_A(aromatic carbon content) of less than 1%, and C_N(naphthenic carbon content) of greater than 30%; and a ratio of 1 ring naphthenes to 2-6 ring naphthenes of less than 1.5

In each of the foregoing embodiments, the lubricant composition may include an olefin copolymer dispersant and one or more extreme pressure agent(s), wherein the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. The ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more extreme pressure agent(s), may deliver between about 350 ppm nitrogen to about 4,800 ppm nitrogen to the lubricant composition and the olefin copolymer dispersant may deliver at least 700 ppm nitrogen to the lubricant composition.

In one embodiment, the lubricant composition may include an olefin copolymer dispersant and one or more extreme pressure agent(s), wherein the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. In this embodiment, the ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. In this embodiment, the olefin copolymer may have a metal content of 10 ppmw or less based on the total weight of the copolymer. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more extreme pressure agent(s), may deliver between about 350 ppm nitrogen to about 4,800 ppm nitrogen to the lubricant composition and the olefin copolymer dispersant may deliver at least 700 ppm nitrogen to the lubricant composition.

The present disclosure also relates to lubricant compositions comprising the olefin copolymer and one or more friction modifier(s) blended in a base oil of lubricating viscosity. The olefin copolymer is derived from ethylene and one or more C₃to C₁₀alpha-olefins and has a number average molecular weight of less than 5,000 g/mol as measured by GPC using polystyrene as a calibration reference. The olefin copolymer has an ethylene monomer moiety content of greater than 40 mol % as measured by ¹H-NMR spectroscopy, a terminal unsaturation of 70 mol % or greater as determined by ¹³C NMR spectroscopy, and at least 70 mol % of the terminal unsaturation selected from terminal vinylidene, one or more tri-substituted isomers of the terminal vinylidene, and any combination thereof, as measured by ¹H-NMR spectroscopy. Further, the olefin copolymer has an experimental average ethylene run length n_{C2,Experimental}, as determined by ¹³C NMR spectroscopy, of less than 2.6 and also satisfies the relationship:

n
_{C2,Experimental}
<n
_{C2,Statistical} (Equation 6).

The one or more friction modifier(s) may be selected from the group consisting of imidazolines, amides, amines, succinimides, alkoxylated amines, oleates, sarcosines, tartrate derivatives, cerium nanoparticles, titanium-containing compounds, and molybdenum-containing compounds, and mixtures thereof. In any of the foregoing embodiments, the one or more friction modifier(s) may be selected from the group consisting of an oleate, oleic acid, an imidazoline or derivatives thereof, an amine, a sarcosine, a tartrate or derivative thereof, cerium nanoparticles, a titanium-containing compound, a dithiocarbamate, and mixtures thereof In any of the foregoing embodiments, the one or more friction modifier(s) may be independently selected from the group consisting of glycerol monooleate, glycerol dioleate, glycerol trioleate, oleic acid, imidazoline derivative, ethoxylated amine, an olelyamine, an olelyl sarcosine, a tartrimide, a tartramide, titanium-containing compound, cerium nanoparticles, molybdenum dithocarbamate, and mixtures thereof. In any of the foregoing embodiments, the one or more friction modifier(s) may be independently selected from the group consisting of glycerol monooleate, glycerol dioleate, glycerol trioleate, oleic acid, 2-(2-heptadec-1-enyl-4,5-dihydroimidazol-1-yl)ethanol, N,N-bis(2-hydroxyethyl)-N-tallow amine, olelyamine, olelyl sarcosine, oleylamine tartrimide, titanium-containing compound obtained from the reaction of titanium alkoxide and neodecanoic acid, cerium nanoparticles obtained from the reaction of cerium (III) acetate, oleic acid, and oleyl amine, molybdenum dithocarbamate, and mixtures thereof.

In any of the foregoing embodiments, the lubricant composition comprises one or more friction modifier(s) and the olefin copolymer dispersant wherein the dispersant can be obtained by reacting the olefin copolymer with an acylating agent to form an acylated copolymer and reacting the acylated copolymer with a nitrogen source. The acylating agent, for each of the foregoing embodiments, may be maleic anhydride. The nitrogen source, for each of the foregoing embodiments, may be ammonia or a polyalkylene polyamine. The polyalkylene polyamine, for each of the foregoing embodiments, may be a mixture of polyethylene polyamines having an average of 5 nitrogen atoms, triethylene tetramine, tetraethylene pentamine, or combinations thereof.

In any of the foregoing embodiments, the lubricant composition comprises one or more friction modifier(s) and the olefin copolymer dispersant wherein the dispersant may be selected from the group consisting of succinimide dispersants, succinic ester dispersants, succinic ester amide dispersants, amide dispersants, ester amide dispersants, and Mannich dispersants. Any of the previously listed olefin copolymer dispersants comprising an olefin copolymer may be phosphorylated, boronated, maleated, phosphorylated and borated, borated and maleate, or phosphorylated and maleated.

In any of the foregoing embodiments, the olefin copolymer may have an ethylene content of at least 49 mol % and less than 80 mol %, or less than 60 mol %. In any of the above embodiments, the one or more C₃to C₁₀alpha-olefins may be selected from the group consisting of propylene, 1-butylene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. In any of the foregoing embodiments, the one or more C₃to C₁₀alpha-olefin may be propylene.

In any of the foregoing embodiments, the one or more friction modifier(s) may be present in the lubricating composition in an amount of up to about 3.0 wt %. In any of the foregoing embodiments, the one or more friction modifier (s) may be present from about 0.1 wt % to about 0.3 wt %, based on the total lubricant composition. In any of the foregoing embodiments, the one or more friction modifier(s) may be present in an amount of about 0.3 wt %, based on the total lubricant composition.

In any of the foregoing embodiments, the one or more friction modifier(s) may be present in an amount from about 0.1 wt % to about 3.0 wt %, and the olefin copolymer dispersant may be present in an amount between 1.0 wt % and about 8.0 wt %, based on the total lubricant composition. In any of the foregoing embodiments, the one or more friction modifier(s) may be present in an amount from about 0.1 wt % to about 0.3 wt %, and the olefin copolymer dispersant may be present in an amount between 1.0 wt % and about 8.0 wt %, based on the total lubricant composition. In any of the foregoing embodiments, the one or more friction modifier(s) may be present in amount of about 0.3 wt %, and the olefin copolymer dispersant may be present in an amount of about 4.0 wt %, based on the total lubricant composition.

In any of the foregoing embodiments, the lubricant composition may contain one or more friction modifier(s) and the olefin copolymer dispersant wherein the olefin copolymer may be derived from ethylene and propylene and may have a number average molecular weight of at least 1300 g/mol, at least about 1390 g/mol, at least about 1600 g/mol, about 1390 g/mol, about 1600 g/mol, about 2700 g/mol, about 1300 g/mol to about 2700 g/mol, or about 1390 g/mol to about 2700 g/mol.

In any of the foregoing embodiments, the one or more friction modifier(s) may be independently selected from the group consisting of glycerol monooleate, glycerol dioleate, glycerol trioleate, oleic acid, imidazoline derivative, ethoxylated amine, olelyamine, olelyl sarcosine, a tartrimide, a tartramide, cerium nanoparticles, titanium-containing compound, molybdenum dithocarbamate, and mixtures, and the one or more C₃to C₁₀alpha-olefins may be propylene and the olefin copolymer may have a number average molecular weight of about 1300 g/mol to about 2700 g/mol.

In any of the foregoing embodiments, the lubricant composition may contain one or friction modifier(s) and the olefin copolymer dispersant may have a formula selected from Formula V, Formula VI, and Formula VII, and mixtures thereof:

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or, together with the N to which they are attached to, form a 5- or 6-membered ring, optionally fused with an aromatic or non-aromatic ring; R₁₀may be H; R₁₁may be H or C₁-C₆alkyl, or —CH₂—(NH—R₇)_n—NR₈R₉; W may be a covalent bond or C(O); and n may be 0, 1, 2, 3, 4, 5, 6, 7, or 8; and y+z=1. In one embodiment, when y=1, R₅is C₁₂to C₃₀. In another embodiment, when y=1, R₅may be C₂₀to C₃₀.

In any of the foregoing embodiments, the lubricant composition may contain one or more friction modifier(s) and the olefin copolymer dispersant of Formula V above, wherein R₈and R₉together with the N to which they are attached form

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In any of the foregoing embodiments, the olefin copolymer dispersant may be post-treated with boric acid and/or maleic anhydride.

In any of the foregoing embodiments, the lubricant composition may include the olefin copolymer dispersant, one or more friction modifier (s), and a base oil of lubricating viscosity selected from a mineral oil, an animal oil, a vegetable oil, a synthetic oil, and mixtures thereof. In any of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than about 120, and a kinematic viscosity at 100° C. from about 2 to about 8 cSt. In any of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than 120, and a kinematic viscosity at 100° C. of about 4 cSt. In any of the foregoing embodiments, the base oil of lubricating viscosity comprises C_P(paraffinic carbon content) of greater than 55%, C_A(aromatic carbon content) of less than 1%, and C_N(naphthenic carbon content) of greater than 30%; and a ratio of 1 ring naphthenes to 2-6 ring naphthenes of less than 1.5.

In each of the foregoing embodiments, the lubricant composition may include an olefin copolymer dispersant and one or more friction modifier(s), wherein the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. The ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more friction modifier(s), may be present from about 0.3 wt % to about 8.0 wt % based on the total lubricant composition.

In one embodiment, the lubricant composition may include an olefin copolymer dispersant and one or more friction modifier(s), wherein the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. In this embodiment, the ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. In this embodiment, the olefin copolymer has a metal content of 10 ppmw or less based on the total weight of the copolymer. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more friction modifier(s), may be present from about 0.3 wt % to about 8.0 wt % based on the total lubricant composition.

The present disclosure also relates to lubricant compositions comprising olefin copolymer dispersant, one or more zinc dithiophosphate(s), and one or more friction modifier(s) blended in a base oil of lubricating viscosity. The olefin copolymer of olefin copolymer dispersant is derived from ethylene and one or more C₃to C₁₀alpha-olefins and has a number average molecular weight of less than 5,000 g/mol as measured by GPC using polystyrene as a calibration reference. The olefin copolymer has an ethylene monomer moiety content of greater than 40 mol % as measured by ¹H-NMR spectroscopy, a terminal unsaturation of 70 mol % or greater as determined by ¹³C NMR spectroscopy, and at least 70 mol % of the terminal unsaturation is selected from terminal vinylidene, one or more tri-substituted isomers of the terminal vinylidene, and any combination thereof, as measured by ¹H-NMR spectroscopy. Further, the olefin copolymer has an experimental average ethylene run length n_{C2,Experimental}, as determined by ¹³C NMR spectroscopy, of less than 2.6 and also satisfies the relationship:

n
_{C2,Experimental}
<n
_{C2,Statistical} (Equation 6).

The one or more zinc dithiophosphate(s) may each comprise 12 to 32 total carbon atoms within alkyl groups thereon and each of the alkyl groups independently averages between 3 to 8 carbon atoms. The one or more friction modifier(s) may independently selected from an oleate, oleic acid, an imidazoline or derivatives thereof, an amine, a sarcosine, a tartrate or derivative thereof, cerium nanoparticles, a titanium-containing compound, a dithiocarbamate, and mixtures thereof. In each of the foregoing embodiments, the lubricant composition may comprise one or more zinc dithiophosphate(s) and one or more friction modifier(s) independently selected from glycerol monoleate, glycerol dioleate, glycerol trioleate, oleic acid, and mixtures thereof.

In each of the foregoing embodiments, the lubricant composition may comprise one or more zinc dithiophosphate(s), one or more friction modifier(s), and the olefin copolymer dispersant obtained by reacting the olefin copolymer with an acylating agent to form an acylated copolymer and reacting the acylated copolymer with a nitrogen source. In each of the foregoing embodiments, the acylating agent is maleic anhydride. The nitrogen source, for each of the foregoing embodiments, may be ammonia or a polyalkylene polyamine. The polyalkylene polyamine, for each of the foregoing embodiments, may be a mixture of polyethylene polyamines having an average of 5 nitrogen atoms, triethylene tetramine, tetraethylene pentamine, or combinations thereof.

In each of the foregoing embodiments the lubricant composition may comprise one or more zinc dithiophosphate(s), one or more friction modifier(s) and the olefin copolymer dispersant wherein the dispersant may be selected from the group consisting of succinimide dispersants, succinic ester dispersants, succinic ester amide dispersants, amide dispersants, ester amide dispersants, and Mannich dispersants. Any of the previously listed olefin copolymer dispersants may be phosphorylated, boronated, maleated, phosphorylated and borated, phosphorylated and maleated, or borated and maleated.

In any of the foregoing embodiments, the olefin copolymer may have an ethylene content of at least 49 mol % and less than 80 mol %, or less than 60 mol %. In any of the foregoing embodiments, the one or more C₃to C₁₀alpha-olefins may be selected from the group consisting of propylene, 1-butylene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene. In any of the foregoing embodiments, the one or more C₃to C₁₀alpha-olefin may be propylene.

In any of the foregoing embodiments the one or more zinc dithiophosphate(s) may be present in an amount to deliver about 800 ppm phosphorus to the lubricant composition and the one or more friction modifier(s) may be present at about 0.5 wt % to about 0.8 wt % based on the total lubricant composition.

In any of the foregoing embodiments, the lubricant composition may contain one or more zinc dithiophosphate(s), one or more friction modifier(s), and the olefin copolymer dispersant wherein the olefin copolymer may be derived from ethylene and propylene and may have a number average molecular weight of at least 1300 g/mol, at least about 1390 g/mol, at least about 1600 g/mol, about 1390 g/mol, about 1600 g/mol, about 2700 g/mol, about 1300 g/mol to about 2700 g/mol, or about 1390 g/mol to about 2700 g/mol.

In any of the foregoing embodiments, the lubricant composition contains one or more zinc dithiophosphate(s), one or more friction modifier(s), and the olefin copolymer dispersant, wherein the one or more friction modifier(s) is independently selected from the group consisting of glycerol monooleate, glycerol dioleate, glycerol trioleate, oleic acid, and mixtures, and the olefin copolymer is derived from ethylene and one or more C₃to C₁₀alpha-olefins, wherein the one or more C₃to C₁₀alpha-olefins may be propylene and the olefin copolymer may have a number average molecular weight of about 1300 g/mol to about 2700 g/mol.

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In each of the foregoing embodiments, the lubricant composition may contain one or more zinc dithiophosphate(s), one or more friction modifier(s), and an olefin copolymer dispersant of Formula V above, wherein R₈and R₉together with the N to which they are attached form

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In each of the foregoing embodiments, the lubricant composition contains one or more zinc dithiophosphate(s), one or more friction modifier(s), and an olefin copolymer dispersant of Formula V above, wherein R₈and R₉together with the N to which they are attached to, form a 5- or 6-membered ring, fused with an aromatic ring of having the following formula

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In each of the foregoing embodiments, the olefin copolymer dispersant may be post-treated with boric acid and/or maleic anhydride.

In each of the foregoing embodiments, the lubricant composition includes the olefin copolymer dispersant, one or more zinc dithiophosphate(s), one or more friction modifier(s), and a base oil of lubricating viscosity selected from a mineral oil, an animal oil, a vegetable oil, a synthetic oil, and mixtures thereof. In each of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than about 120, and a kinematic viscosity at 100° C. from about 2 to about 8 cSt. In each of the foregoing embodiments, the base oil of lubricating viscosity may have less than about 25 ppm sulfur, a viscosity index greater than 120, and a kinematic viscosity at 100° C. of about 4 cSt. each of the foregoing embodiments, the base oil of lubricating viscosity may comprise C_P(paraffinic carbon content) of greater than 55%, C_A(aromatic carbon content) of less than 1%, and C_N(naphthenic carbon content) of greater than 30%; and a ratio of 1 ring naphthenes to 2-6 ring naphthenes of less than 1.5.

In one embodiment, the lubricant composition may include an olefin copolymer dispersant, one or more zinc dialkyl dithiophosphate(s), and one or more friction modifier(s), wherein the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. In this embodiment, the ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more zinc dialkyl dithiophosphate(s) may be present in an amount to deliver about 800 ppm phosphorus to the lubricant composition. The one or more friction modifier(s), may be present from about 0.3 wt % to about 8.0 wt % based on the total lubricant composition.

In one embodiment, the lubricant composition may include an olefin copolymer dispersant, one or more zinc dialkyl dithiophosphate(s), and one or more friction modifier(s), wherein the olefin copolymer may be derived from ethylene and propylene and may have a Mn of at least 1300 g/mol. In this embodiment, the ethylene monomer moiety content of the copolymer may be at least 49 mol % and less than 60 mol %. In this embodiment, the olefin copolymer has a metal content of 10 ppmw or less based on the total weight of the copolymer. The olefin copolymer dispersant may be obtained by reacting the olefin copolymer with maleic anhydride to form an acylated copolymer, which is reacted with a polyethylene polyamine having 5 or an average of 5 nitrogen atoms, to form a succinimide dispersant. The one or more zinc dialkyl dithiophosphate(s) may be present in an amount to deliver about 800 ppm phosphorus to the lubricant composition. The one or more friction modifier(s), may be present from about 0.3 wt % to about 8.0 wt % based on the total lubricant composition.

This disclosure also provides for a method of evaluating the properties of a lubricant composition including the olefin copolymer described herein in combination with any of the additives described above in this Summary and may be evaluated in an apparatus selected from: a Brookfield viscometer, a Vickers Test apparatus; an SAE No. 2 friction test machine; an electric motor-driven Hydra-Matic 4L60-E automatic transmission; test equipment for elastomer compatibility per ASTM D471 or D676; a NOACK volatility procedure machine; an apparatus for testing wear procedures under ASTM D2882, D5182, D4172, D3233, or D2782; test apparatus for evaluating copper corrosion tester under ASTM D130; test equipment specified by the International Harvester Procedure Method BT-9 Rust Control test; test apparatus to evaluate foaming under ASTM D892 or D6082; test apparatus to measure gear anti-wear performance under ASTM D4998; a Link M1158 Oil/Friction Machine; a L-33-1 Test Apparatus; a L-37 Test Apparatus; a L-42 Test Apparatus; a L-60-1 Test Apparatus; a Strama 4-Square Electric Motor-Driven Procedure Machine; a FZG Test Apparatus; a SSP-180 Procedure Machine; a test apparatus for measuring high temperature cycle durability under ASTM D5579; a Sauer-Danfoss Series 22 or Series 90 Axial Piston Pump; a John Deere Synchro-Plus transmission; an SRV-friction wear tester; a 4-ball test apparatus; an LFW-1 test apparatus; a sprag clutch over-running wear test apparatus; an apparatus to perform API CJ-4, CF, and CF-2 engine tests; an apparatus to perform a L-33 moisture corrosion test; an apparatus to measure high-temperature cyclic durability per ASTM D 5579; an apparatus to perform a 288-hour VE engine oil performance test; an apparatus to perform a L-38 standard lubricant test; a Denison P46 Piston Pump Test Stand; a Sundstrand Dynamic Corrosion Test Stand; a block-on-ring test apparatus; any test apparatus required for performing test analysis under Mercon®, Mercon® V, Dexron® III, Dexron® III-H, Caterpillar® TO-4, Allison® C-4, JASO, GF-4, GF-5, MIL-E, MIL-L, and Sequences II through VIII; an apparatus to perform Mack T-11, T-12, or T13 engine lubricant tests per ASTM 7156, D7422, or D8048; an apparatus to perform a DD13 scuffing wear test per ASTM D8074; an apparatus to perform MB seals tests or AK6 seals; an apparatus to perform Cummins ISM or ISB wear tests per ASTM D7468 or D7484; an apparatus to perform a CAT oxidation test; and apparatus to perform CAT C13, IN, 1P, 1K tests per ASTM D7549, D6750, D6681, D6750; any apparatus to perform a CAT Aeration test; an apparatus to perform shear stability tests; an apparatus to perform a Volvo D12D evaluation; an apparatus to perform a Sequence IIIF or IIIG test per ASTM D6984 or D7320; an apparatus to perform a Sequence IIIH, IIIHA or IIIB test per ASTM D8111, an apparatus to perform a Sequence IVB or VH test; an apparatus to perform a Sequence VIE test per ASTM D8114; an apparatus to perform a Sequence VIF evaluation; an apparatus to perform a Sequence VIII test per ASTM D6704; an apparatus to perform a Sequence IX or X test; an apparatus to measure deposit formation under at least ASTM D6335; an apparatus to measure filterability tests per one or more of ASTM D6794 or D6795; an apparatus to measure homogeneity or miscibility tests under at least ASTM D6922; an apparatus to evaluate rust under at least ASTM D6557; an apparatus to perform an emulsion test under at least ASTM D7563; an apparatus to perform elastomer compatibility tests under at least ASTM D7216; and combinations thereof.

DETAILED DESCRIPTION

The lubricating oil compositions herein include the olefin copolymer dispersants combined with select additional lubricant compounds to achieve a low boundary friction as measured on a High Frequency Reciprocating Rig (HFRR). The lubricating compositions having the olefin copolymer dispersants herein also possess acceptable low temperature viscosity. Additives that may be combined with the olefin copolymer dispersants may include a metal-containing phosphorus-containing compound, an ashless phosphorus-containing compound, one or more detergent(s), one or more extreme pressure agent(s), one or more friction modifier(s), and combinations thereof.

Olefin Copolymer Dispersant

Lubricants of the present invention comprise olefin copolymer dispersants, wherein the olefin copolymer is derived from ethylene and one or more C₃-C₁₀alpha-olefin. As used herein, an “ethylene monomer moiety” generally refers to a —H₂C—CH₂— unit within a copolymer chain, which is derived from an ethylene molecule during copolymerization, with a similar definition applying to “C₃-C₁₀alpha-olefin monomer moiety.”

The olefin copolymer dispersants herein can be present in the lubricating composition an amount from about 1 weight percent to about 10 weight percent or from about 1 weight percent to about 8 weight percent, or about 1 weight percent to about 5 weight percent, based on the total lubricant composition.

The olefin copolymer portion of the dispersants described herein have a number of polymer characteristics that define its uniqueness in terms of a lubricant, such as average ethylene run length, particular molecular weights, ethylene monomer moiety mol % incorporation into the copolymer, alpha-olefin monomer moiety mol % incorporation into the copolymer, terminal unsaturation mol %, select polymer terminal end groups, copolymer functionalization, and/or various post-treatment methods. These olefin copolymer dispersants have a number of performance benefits when used in lubricants, including lowering friction coefficients and improving cold weather performance as evidenced by relatively small changes to low temperature complex viscosity. Further details of these features, additional features, tests to measure the uniqueness of olefin copolymer portion of the dispersants described herein, and methods of making the copolymer and dispersants can be found in co-pending U.S. patent application Ser. No. 15/377,152 and co-pending U.S. patent application Ser. No. 15/377,788, both filed on Dec. 13, 2016, which are both incorporated herein by reference in their entirety.

Dispersants typically include relatively long chain polymeric materials with an oleophilic component providing oil solubility and a polar component providing dispersancy. As used herein, the term “dispersant” also includes materials having a relatively shorter oleophilic component, e.g., C₁₂-C₃₀or C₂₀-C₃₀polymeric materials. Accordingly, unless otherwise specified, the olefin copolymer dispersants described herein may include olefin copolymers having C₁₂-C₃₀hydrocarbyl chains. Due to their shorter chain, these materials may function as friction modifiers.

Number Average Molecular Weight (Mn)

The number average molecular weight (Mn) of the copolymers herein was determined with a gel permeation chromatography (GPC) instrument obtained from Waters and the data was processed with Waters Empower Software. The GPC instrument is equipped with a Waters Separations Module and Waters Refractive Index detector. The GPC operating conditions include a guard column, 4 Agilent PLgel columns (length of 300×7.5 mm; particle size of 5μ, and pore size ranged from 100-10000 Å) with the column temperature at 40° C. Unstabilized HPLC grade tetrahydrofuran (THF) was used as solvent, at a flow rate of 1.0 mL/min. The GPC instrument was calibrated with commercially available polystyrene (PS) standards having a narrow molecular weight distribution ranging from 500-380,000 g/mol. The calibration curve was extrapolated for samples having a mass less than 500 g/mol. Samples and PS standards were in dissolved in THF and prepared at concentration of 0.1-0.5 wt % and used without filtration.

GPC measurements for ethylene-propylene copolymers are described in U.S. Pat. No. 5,266,223, which is incorporated herein by reference. The GPC method additionally provides molecular weight distribution information; see, for example, W. W. Yau, J. J. Kirkland and D. D. Bly, “Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, New York, 1979, also incorporated herein by reference.

The copolymers of the dispersants described herein have a Mn of less than 5,000 g/mol. The copolymers may have a Mn less than about 4,500 g/mol, less than about 4,000 g/mol, less than about 3,500 g/mol, less than about 3,000 g/mol, less than 2,800 g/mol, less than 2,500 g/mol, less than 2,000 g/mol, less than 1,500 g/mol, less than 1,200 g/mol, less than about 1,000 g/mol, less than 900 g/mol, or less than 800 g/mol. The copolymer may have an Mn of at least about 200 g/mol, at least about 500 g/mol, at least about 700 g/mol, at least about 800 g/mol, at least about 1,000 g/mol, at least about 1,400 g/mol, at least about 1,600 g/mol, or at least about 2700 g/mol. Combinations of any of the above-referenced ranges are also possible (for example, about 200 g/mol to about 1,500 g/mol, at least about 700 g/mol and less than about 1,500 g/mol, at least about 800 g/mol and less than about 1,500 g/mol, or at least about 500 g/mol and less than about 1,500 g/mol and so forth, with all the above noted endpoints). In some embodiments, the Mn of the copolymer is at least about 1,300 g/mol to about 2,700 g/mol or about 1,390 g/mol to about 2,700 g/mol. In other embodiments, the Mn of the copolymer is about 1,300 g/mol, about 1,390 g/mol, about 1,600 g/mol, or about 2,700 g/mol.

The polydispersity index (PDI) of the copolymer is a measure of the variation in size of the individual chains of the copolymer. The PDI is determined by dividing the weight average molecular weight of the copolymer by the number average molecular weight of the copolymer. The term “number average molecular weight” (Mn) is given its ordinary meaning in the art, and is defined as the sum of the products of the weight of each polymer chain and the number of polymer chains having that weight, divided by the total number of polymer chains. The term “weight average molecular weight” (Mw) is given its ordinary meaning in the art and is defined as the sum of the products of the weight squared of each polymer chain and the total number of polymer chains having that weight, divided by the sum of the products of the weight of each polymer chain and the number of polymer chains having that weight. Both the Mw and Mn were determined using the GPC method described herein. The PDI of the copolymers herein may be less than or equal to about 4, less than or equal to about 3, less than or equal to about 2, or less than or equal to about 1.

Ethylene Monomer Moiety Content:

The copolymers herein include an ethylene monomer moiety content of greater than 40 mol %, as measured by ¹H-NMR spectroscopy. The ethylene monomer moiety content of the copolymer may be at least about 45 mol %, at least about 50 mol %, at least about 55 mol %, at least about 60 mol %, at least about 65 mol %, at least about 70 mol %, or at least about 75 mol %. The ethylene monomer moiety content of the copolymer may be less than about 90 mol %, less than about 80 mol %, less than about 75 mol %, less than about 70 mol %, less than about 65 mol %, less than about 60 mol %, less than about 55 mol %, less than about 50 mol %, or less than about 45 mol %. Combinations of the above-referenced ranges are also possible (for example, greater than 40 mol % and less than about 80 mol %, greater than 40 mol % and less than about 70 mol %, greater than 40 mol % and less than about 65 mol %, greater than 40 mol % and less than about 60 mol %, greater than 40 mol % and less than 50 mol %, greater than 50 mol % and less than 55 mol %, at least 49 mol % and less than 80 mol %, at least 49 mol % and less than 60 mol %, and so forth with all the above noted endpoints). In some embodiments, the ethylene monomer moiety content of the copolymer is 49 mol %, 51 mol %, or 53 mol %.

C₃-C₁₀Alpha-Olefin Monomer Moiety Content

The copolymers herein also include one or more C₃-C₁₀alpha-olefin monomer moiety(ies). The C₃-C₁₀alpha-olefin monomer moieties have a carbon number from three to ten. Thus, the carbon number of the C₃-C₁₀alpha-olefin monomer moieties may be 3, 4, 5, 6, 7, 8, 9, or 10. For example, the C₃-C₁₀alpha-olefin monomer moieties may be derived from propylene. In other embodiments, the C₃-C₁₀alpha-olefin monomer moieties may be derived from 1-butylene-, 1-pentene-, 1-hexene-, 1-heptene-, 1-octene-, 1-nonene-, or 1-decene.

The term “olefin” is given its ordinary meaning in the art, and generally refers to a family of organic compounds which are alkenes with a chemical formula C_xH_2x, where x is the carbon number and having a double bond within its structure. The term “alpha-olefin” is also given its ordinary meaning in the art and refers to olefins having a double bond within its structure at the primary or alpha position.

The copolymers herein include a C₃-C₁₀alpha-olefin monomer moiety(ies) content of less than 60 mol %, which can be measured by ¹H NMR spectroscopy. The C₃-C₁₀alpha-olefin monomer moiety(ies) content of the copolymers herein may be less than about 55 mol %, less than about 50 mol %, less than about 45 mol %, less than about 40 mol %, less than about 35 mol %, less than about 30 mol %, less than about 25 mol %, or less than about 20 mol %. The C₃-C₁₀alpha-olefin monomer moiety(ies) content of the copolymers herein may be at least about 20 mol %, at least about 25 mol %, at least about 30 mol %, at least about 35 mol %, at least about 40 mol %, at least about 45 mol %, at least about 50 mol %, at least about 55 mol %, at least about 59 mol %. Combinations of the above reference ranges are possible (or example, at least about 40 mol %, and less than about 60 mol %, at least about 50 mol % and less than 60 mol %, at least about 45 mol % and less than 50 mol %, and so forth with the various endpoints noted above). In some embodiments, the C₃-C₁₀alpha-olefin monomer moiety(ies) content of the copolymer is 51 mol %, 49 mol % or 47 mol %.

Terminal Unsaturation:

The copolymers herein may terminate with either an ethylene monomer moiety or a C₃-C₁₀alpha olefin monomer moiety and include at least about 70 mol % terminal unsaturation. “Terminal unsaturation” refers to a carbon-carbon double bond wherein at least one of the carbons is derived from the terminal monomer moiety, either the ethylene monomer moiety or the C₃-C₁₀alpha olefin monomer moiety of the copolymer. The copolymer may have greater than 75 mol % terminal unsaturation, greater than 80 mol % terminal unsaturation, greater than 85 mol % terminal unsaturation, greater than 90 mol % terminal unsaturation, greater than 95 mol % terminal unsaturation, greater than 97 mol % terminal unsaturation. The mol % of terminal unsaturation is determined by ¹³C NMR. See, e.g., U.S. Pat. No. 5,128,056, which is incorporated herein by reference.

Terminal Group:

If the copolymer terminates in an ethylene monomer moiety, the terminal group on the copolymer is vinyl or di-substituted isomer of vinyl. If the copolymer terminates in C₃-C₁₀alpha-olefin monomer moiety, the terminal group on the copolymer is a vinylidene, one or more tri-substituted isomers of a terminal vinylidene, or any combination thereof. In the copolymer of the dispersants described herein, at least 70 mol % of the terminal unsaturation is derived from a C₃-C₁₀alpha olefin. That is, at least 70 mol % of the terminal unsaturation is selected from terminal vinylidene, one or more tri-substituted isomers of a terminal vinylidene having one or more of the following structural Formulas I-III, and any combination thereof:

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For Formulas I-III, R_arepresents an alkyl (e.g., methyl if the terminal group is derived from propylene, ethyl if the terminal group is derived from 1-butene, etc.) and “

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” indicates the bond is attached to the remaining portion of the copolymer.

The copolymer of the dispersants herein may have greater than about 75 mol %, greater than about 80 mol %, greater than about 85 mol %, greater than about 90 mol %, or greater than about 95 mol %, terminal vinylidene, one or more tri-substituted isomers of the terminal vinylidene derived from a C₃-C₁₀alpha olefin monomer, or any combination thereof.

As used herein, the term “terminal vinylidene” refers to the structure represented by Formula I. As used herein, the term “tri-substituted isomer of terminal vinylidene” refers to the structure represented by Formulas II and/or III. Terminal vinylidene, tri-substituted isomers of terminal vinylidene, and other types of terminal unsaturated bonds can be detected by ¹H-NMR. From the integrated intensity of each signal, the amount of each unsaturated bond can be determined, as discussed in U.S. Patent Publication No. 2016/0257862, which is incorporated herein by reference.

Average Ethylene Run Length and Triad Distribution

The dispersants herein comprise copolymers having ethylene monomer moieties and C₃-C₁₀alpha-olefin monomer moieties arranged in such a way as to provide good low temperature performance, including relatively small changes to low temperature complex viscosity and low temperature pumping viscosity (i.e., MRV performance).

The arrangement of the ethylene monomer moieties may be characterized by an “average ethylene run length.” As used herein, “average ethylene run length” refers to the average ethylene monomer moiety run length incorporated into the copolymer. In a copolymer comprising ethylene and alpha-olefin monomer moieties (e.g., ethylene and propylene monomer moieties), neither of the monomer moieties will be distributed uniformly along the chain of the copolymer. Instead, the monomer moieties will be randomly distributed. For example, in a representative copolymer comprising four monomer moieties of A, and four monomer moieties of B, the monomer moieties may be distributed as follows: A-A-B-A-B-B-B-A, or in any other manner. The average run length of a monomer moiety within the copolymer is determined by dividing the total number of that monomer moiety within the copolymer by the number of separate runs of that monomer moiety. In the above example, there are a total of four monomer moieties of A and three separate runs of A. Therefore, the average A run length is 1.33. There are a total of four monomer moieties of B and two separate runs of B. Therefore, the average B run length is 2.0.

A theoretical average ethylene run length (n_{C2,statistical}) for the copolymers herein can be calculated from Bernoullian statistics, shown in the equations below. Equation 1 uses the experimentally measured mole fraction of ethylene incorporated in the copolymer, x_C2, to calculate the theoretical mole fraction of particular triads, which is used to calculate n_{C2,Statistical}. Triads are the possible combinations of three sequential monomer moieties in a copolymer. For example, in an ethylene-propylene copolymer, where “E” represents an ethylene monomer moiety and “P” represents a propylene monomer moiety, potential combinations for triads include: E-E-E, E-E-P, P-E-E, P-E-P, E-P-E, P-P-E, and P—P-P.

To calculate the theoretical average ethylene run length (n_{C2,statistical}), the mole fraction of ethylene incorporated in the copolymer, x_C2, is determined by ¹H-NMR spectroscopy. x_C2is then inserted into Equations 2-4 to calculate the mole fractions of the triads, EEE, EEA, AEE, and AEA to determine n_{C2,Statistical}for a purely theoretical copolymer based on the statistical distributions of the triads.

$\begin{matrix} n_{C 2, Statistical} = \frac{(EEE) + (AEE + EEA) + (AEA)}{(AEA) + 0.5 (AEE + EEA)} & (Equation 1) \\ (EEE) = {(x_{C 2})}^{3} & (Equation 2) \\ (AEE + EEA) = 2 {(x_{C 2})}^{2} (1 - x_{C 2}) & (Equation 3) \\ (AEA) = {x_{C 2} (1 - x_{C 2})}^{2} & (Equation 4) \end{matrix}$

The olefin copolymers of the dispersants herein have an experimentally obtained average ethylene run length (n_{C2,Experimental}) less than the theoretical average ethylene run length (n_{C2,statistical}). n_{C2,Experimental}of the copolymers herein is determined by calculating the mole fractions of the triads based on ¹³C NMR of the copolymer. The method used for experimentally calculating the mole fraction of the triads of ethylene-propylene copolymers is described in J. C. Randall JMS—Review Macromolecules Chem Physics C29, 201 (1989) and E. W. Hansen, K. Redford Polymer Vol. 37, No. 1, 19-24 (1996), both of which are incorporated herein by reference. ¹³C-NMR data is collected on the copolymer and eight chemical shift regions (A-H), shown in Table 1 are integrated. To calculate the mole fractions of the triads, the integrations of the regions are measured and applied to the equations in Table 2. The values of the mole fractions of the triads are then normalized. For the copolymers described herein, the D, E, and F regions are combined due to peak overlap, k is a normalization constant, and T=total integrated region. The factor k is the NMR proportionality constant relating the observed resonance intensities to the number of contributing molecular species. It can later be removed through normalization once a complete set of triads is obtained, as explained in J. C. Randall JMS—Review Macromolecules Chem Physics C29, 201 (1989). Table 1 and Table 2 are specifically intended to calculate the mole fractions of the triads found within an ethylene-propylene copolymer. It is within one of skill in the art to modify the ¹³C NMR data collection to calculate the triad mole fractions of copolymers comprising ethylene monomer moieties and other C₄-C₁₀alpha olefin monomer moieties.

TABLE 1

Integral Regions

Region
Chemical Shift (ppm)

A
43.5-48.0

B
36.5-39.5

C
32.5-33.5

D
29.2-31.2

E
28.5-29.3

F
26.5-27.8

G
23.5-25.5

H
19.5-22.5

TABLE 2

Equations

k(EEE) = 0.5(T_DEF+ T_A+ T_C+ 3T_G− T_B− 2T_H)

k(PEE + EEP) = 0.5(T_H+ 0.5T_B− T_A− 2T_G)

k(PEP) = T_G

k(EPE) = T_C

k(EPP + PPE) = 0.5(2T_H+ T_B− 2T_A− 4T_C)

k(PPP) = 0.5(3T_A+ 2T_C− 0.5T_B− T_H)

The calculated mole fraction of the EEE, AEE, EEA, and AEA triads are entered into Equation 5 in order to obtain n_{C2,Experimental}. When measurements and calculations from an ethylene-propylene copolymer are used in Equation 5, AEE is PEE, EEA is EEP, AEA is PEP.

$\begin{matrix} n_{C 2, Experimental} = \frac{(EEE + (AEE + EEA) + AEA)}{(AEA + 0.5 (AEE + EEA))} & (Equation 5) \end{matrix}$

The copolymers of the dispersants herein have an experimentally obtained average ethylene run length (n_{C2,Experimental}) less than the theoretical average ethylene run length (n_{C2,Statistical}) and thus satisfy the relationship below:

n
_{C2,Experimental}
<n
_{C2,Statistical} (Equation 6)

Not only do the olefin copolymers of the dispersants herein have an n_{C2,Experimental}less than n_{C2,Statistical}, but the copolymers must also have a n_{C2,Experimental}less than 2.6. The copolymers of the dispersants having an n_{C2,Experimental}less than 2.6 exhibit improved cold weather performance, as evidenced by passing the MRV test (ASTM D4684-14) and which is further described in co-pending U.S. patent application Ser. No. 15/377,788, which is incorporated herein by reference in its entirety. Accordingly, the copolymers of the dispersants herein may have n_{C2,Experimental}less than 2.5, less than 2.4, less than 2.3, less than 2.1, less than 2.0, or less than 1.9.

The copolymers may have an E-E-E amount of less than about 20%, less than about 10%, or less than about 5%, which is an indication of a relatively short n_{C2,Experimental}.

Copolymers having the properties described above, i.e., n_{C2,Experimental}of less than 2.6 and satisfying Equation (6) have improved plasticization efficiency, plasticization durability, oxidative stability of the plasticizer and improved low temperature properties. Dispersants comprising these copolymers, when used in lubricants, have improved friction coefficients and improved low temperature properties.

Olefin Copolymer Functionalization:

The dispersants herein are prepared by functionalizing the copolymer described above through a variety of well-known chemical mechanisms to incorporate one or more functional portions into the copolymer via the terminal unsaturation in the copolymer. As described above at least 70 mol % of the terminal unsaturation of the copolymer is selected from terminal vinylidene, one or more tri-substituted isomers of the terminal vinylidene, and any combination thereof. Accordingly, the dispersants herein are derived from functionalizing olefin copolymers wherein at least 70 mol % of the terminal unsaturation of the olefin copolymers is selected from terminal vinylidene, one or more tri-substituted isomers of a terminal vinylidene, and any combination thereof (see Formulas I-III). The dispersants may be derived from functionalizing olefin copolymers wherein at least 70 mol %, at least 75 mol %, at least 80 mol %, at least 85 mol %, at least 90 mol %, or at least 95 mol % of the terminal unsaturation of the olefin copolymers is selected from terminal vinylidene, one or more tri-substituted isomers of a terminal vinylidene of Formulas I-III, and any combination thereof.

The olefin copolymer dispersants herein may be hydrocarbyl amines, amides, carboxylic acids and functionalized glycols, imidazolines, succinimides, succinamides, triazines, succinic ester/acids or ester/amides, Mannich products, alkyl sulphonic acids, esters, hydrocarbyl hydroxy benzoates, betaines, and quaternary ammonium salts, etc. These dispersants may be prepared through one of many known chemical mechanisms, e.g., imidization, succinimide formation, Koch reaction, Mannich reaction, hydroformylation-reductive-amination, or halogenation-amination. Some methods of functionalizing copolymers are taught in U.S. Pat. No. 5,936,041 and co-pending U.S. patent application Ser. No. 15/377,788, which are incorporated herein by reference.

Succinimide formation is well-known in the art and may be accomplished by converting the copolymer described herein to an acylated copolymer (e.g., alkenyl succinic acid or anhydride) which is subsequently reacted with a nitrogen source, to form an olefin copolymer dispersant, i.e., an olefin copolymer succinimide dispersant. The acylated copolymer can be made by reacting the double bond on the terminal end group of the copolymer with an acylating agent (e.g., maleic acid or maleic anhydride) via thermal ene reaction and/or halogenation-condensation, see, e.g., U.S. Pat. No. 7,897,696, which is incorporated herein by reference. In an acylated copolymer such as an alkenyl succinic acid or anhydride, the ratio of succinic moiety:copolymer backbone is about 0.8:1 to about 2:1, or about 1:1 to about 1.8:1, or about 1.2:1 to about 1.5:1.

The acylating agent of the above process is an unsaturated substituted or un-substituted organic acid or anhydride, for example maleic or fumaric reactants of the general formula:

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wherein X and X′ are the same or different, provided that at least one of X and X′ is a group that is capable of reacting to esterify alcohols, forming amides or amine salts with ammonia or amines, forming metal salts with reactive metals or basically reacting metal compounds, or otherwise functioning as an acylating agent. Typically, X and/or X′ is —OH, —O-hydrocarbyl, —NH₂, and taken together X and X′ can be —O— so as to form an anhydride. In some embodiments, X and X′ are such that both carboxylic functions can enter into acylation reactions.

Maleic anhydride is a suitable acylating agent. Other suitable acylating agents include electron-deficient olefins such as monophenyl maleic anhydride; monomethyl maleic anhydride, dimethyl maleic anhydride, N-phenyl maleimide and other substituted maleimides; isomaleimides; fumaric acid, maleic acid, alkyl hydrogen maleates and fumarates, dialkyl fumarates and maleates, fumaronilic acids and maleanic acids; and maleonitrile and fumaronitrile.

As mentioned above, conversion of the acylated copolymer, such as alkenyl succinic acid or anhydride to a succinimide is well-known in the art and may be accomplished through reacting the acylated copolymer with a nitrogen source, such as ammonia, or an amine, such as a polyamine having at least one basic nitrogen. Conversion of an alkenyl succinic acid or anhydride into a succinimide in described in U.S. Pat. Nos. 3,215,707 and 4,234,435, both of which are incorporated herein by reference. Suitable nitrogen sources include ammonia, monoamines, polyamines, polyalkylene polyamines, and mixtures thereof. The polyalkylene polyamines may include mixtures of polyethylene polyamines having an average of 5 nitrogen atoms, triethylene tetramine (TETA), tetraethylene pentamine (TEPA), and combinations thereof.

The amines used herein are well-known in the art and generally have at least one reactive N—H bond (nitrogen to hydrogen bond). The amine is optionally further substituted with other functional groups, such as a hydroxyl. In one embodiment, the amine contains one or more primary or secondary amino groups. The monoamine in one embodiment has 1 to 22 carbon atoms. Examples of a monoamine include butylamine, methylamine, dimethylamine, an alkanolamine containing one or more hydroxy groups such as ethanolamine, or mixtures thereof.

In some cases, the polyalkylene polyamines may have at least three nitrogen atoms and about 4 to 20 carbon atoms. One or more oxygen atoms may also be present in the polyamine. Several polyamines can be used in preparing the dispersant. In addition to the nitrogen sources mentioned above, non-limiting exemplary polyamines may include aminoguanidine bicarbonate (AGBC), ethylene diamine (EDA), N-methyl propylene diamine, diethylene triamine (DETA), pentaethylene hexamine (PEHA), or other heavy polyamines. Some heavy polyamines may comprise a mixture of polyalkylene polyamines having small amounts of lower polyamine oligomers such as TEPA and PEHA, having but primarily polyamine oligomers having seven or more nitrogen atoms, two or more primary amines per molecule, and more extensive branching than conventional polyamine mixtures. Additional non-limiting polyamines which may be used to prepare the dispersant are disclosed in U.S. Pat. No. 6,548,458, the disclosure of which is incorporated herein by reference in its entirety.

Other examples of suitable polyalkylene polyamines include, but are not limited to, propylene diamine, isopropylene diamine, butylene diamine, pentylene diamine, hexylene diamine, dipropylene triamine, dimethylaminopropyl amine, diisopropylene triamine, dibutylene triamine, di-sec-butylene triamine, tripropylene tetraamine, triisobutylene tetraamine, pentaethylene hexamine, and mixtures thereof.

A particularly suitable group of polyalkylene polyamines may contain from about 2 to about 12 nitrogen atoms and from about 2 to about 24 carbon atoms. The alkylene groups of such polyalkylene polyamines may contain from about 2 to about 6 carbon atoms, more preferably from about 2 to about 4 carbon atoms. Many of the polyamines suitable for use in the present disclosure are commercially available and others may be prepared by methods which are well known in the art. For example, methods for preparing amines and their reactions are detailed in Sidgewick's “The Organic Chemistry of Nitrogen”, Clarendon Press, Oxford, 1966; Noller's “Chemistry of Organic Compounds”, Saunders, Philadelphia, 2nd Ed., 1957; and Kirk-Othmer's “Encyclopedia of Chemical Technology”, 2nd Ed., especially Volume 2, pp. 99-116, each of which is incorporated herein by reference.

Additional amines that can be used in forming the dispersant include an alkanolamine containing one or more hydroxy groups such as 2-(2-aminoethylamino) ethanol, aminoalkyl substituted heterocyclic compounds such as 1-(3-aminopropyl)imidazole and 4-(3-aminopropyl) morpholine, condensates of polyamines with polyhydroxy compounds such as condensates of polyethylene polyamines with tris(hydroxymethyl)aminomethane as described in U.S. Pat. No. 5,653,152, or mixtures thereof.

The reaction of the nitrogen source, such as ammonia or polyamine and the alkenyl succinic acid or anhydride affords mono-succinimide, bis-succinimide, tris-succinimide, or other succinimides depending on the charge ratio of the nitrogen source and alkenyl succinic acid or anhydride. The charge ratio between alkenyl succinic acid or anhydride and nitrogen source is about 1:1 to about 3.2:1, or about 2.5:1 to about 3:1, or about 2.9:1 to about 3:1, or about 1.6:1 to about 2.5:1, or about 1.6:1 to about 2:1, or about 1.6:1 to about 1.8:1, about 1.3:1 to about 1.8:1, about 1.4:1 to about 1.8:1, or about 1:6 to about 1.8:1.

The dispersants herein may be prepared by a process comprising: (1) coupling an olefin copolymer derived from ethylene and one or more C₃to C₁₀alpha-olefins and having the characteristics described herein with an unsaturated mono- or dicarboxylic acid or anhydride to form a copolymer substituted with mono- or dicarboxylic acid or anhydride; (2) reacting the copolymer substituted with mono- or dicarboxylic acid or anhydride with a nitrogen source, such as ammonia or a polyamine having at least one basic nitrogen; and (3) optionally post-treating the reaction product of step (2).

It will be appreciated that other dispersants can be prepared from the copolymers herein by known chemical reaction at the terminal double bond of the copolymer. Therefore, this invention also includes, in various embodiments, such methods and dispersants prepared therefrom.

As non-limiting examples, the olefin copolymer dispersant described herein may have the structure of the following compounds.

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In Formulas V, VI, and VII, R₅is a hydrocarbyl radical derived from the copolymer, derived from ethylene and one or more C₃to C₁₀alpha-olefins. R₆is a divalent C₁-C₆alkylene. R₇is a divalent C₁-C₆alkylene. W is a covalent bond or C(O). Each of R₈and R₉, independently, is H, C₁-C₆alkyl,

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or together with the N to which they are attached to, form a 5- or 6-membered ring, optionally fused with an aromatic or non-aromatic ring. R₁₀is H. R₁₁is H or C₁-C₆alkyl, or —CH₂—(NH—R₆)_n—NR₈R₉; and n is 0, 1, 2, 3, 4, 5, 6, 7, or 8; and y+z=1.

In one embodiment, the olefin copolymer dispersant has the structure of Formula V wherein y=1 and R₅is C₁₂to C₃₀. In another embodiment, when y=1, R₅is C₂₀to C₃₀. In another embodiment, the olefin copolymer dispersant has the structure of Formula V wherein y=0 and n=4.

In Formula V above, the olefin copolymer dispersant can be mono-succinimide, or bis-succinimide, i.e., NR₈R₉together is of Formula IX and R₅is hydrocarbyl derived from the copolymer as described above:

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In another embodiment, the olefin copolymer dispersant has the structure of Formula V above, and R₈and R₉together with the N to which they are attached to, form a 5- or 6-membered ring, fused with an aromatic ring of having the following formula

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If the olefin copolymer dispersant has the generic structure of Formula VII, it may have one of the following more specific structures:

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Post-Treatment:

The olefin copolymer dispersant herein may be post-treated by conventional methods via a reaction with any of a variety of agents, which are known in the art. Among these are boron compounds, urea, thiourea, thiadiazoles and derivatives thereof, carbon disulfide, aldehydes, ketones, carboxylic acids, anhydrides, nitriles, epoxides, cyclic carbonates, zinc compounds, molybdenum compounds, and phosphorus compounds. See, for example, U.S. Pat. No. 5,241,003, which is incorporated herein by reference. Additional references that describe methods for preparing a boron containing and/or zinc containing dispersants are set forth in U.S. Pat. Nos. 3,163,603 and 3,087,936.

The boron compound used as a post-treating reagent can be selected from the group consisting of boron oxide, boron halides, boron acids and esters of boron acids in an amount to provide from about 0.1 atomic proportion of boron for each mole of the nitrogen composition to about 20 atomic proportions of boron for each atomic proportion of nitrogen used. The dispersant post-treated with boron may contain from about 0.05 to about 2.0 wt %, or in other approaches, about 0.05 to about 0.7 wt % boron, based on the total weight of the borated dispersant.

In one embodiment the process of post-treating the dispersant comprises forming the succinimide product, as described above and further reacting the succinimide product with a boron compound, such as boric acid.

Carboxylic acid used as a post-treating reagent can be saturated or unsaturated mono-, di-, or poly-carboxylic acid. Examples of carboxylic acid include, but are not limited to, maleic acid, fumaric acid, succinic acid, and naphthalic diacid (e.g., 1,8-naphthalic diacid).

Anhydride used as a post-treating reagent can be selected from the group consisting of mono-unsaturated anhydride (e.g., maleic anhydride), alkyl or alkylene-substituted cyclic anhydrides (e.g., succinic anhydride or glutamic anhydride), and aromatic carboxylic anhydrides (including naphthalic anhydride, e.g., 1,8-naphthalic anhydride).

In some cases, the olefin copolymer dispersant herein may be post-treated with more than one post-treatment agents. For example, the dispersant may be post-treated with a boron compound, such as boric acid, and an anhydride, such as maleic anhydride and/or 1,8-naphthalic anhydride. The dispersant may also be post-treated with or with boron compound, such as boric acid, and an anhydride, such as maleic anhydride.

In some cases the dispersant may be post treated with other conventional post-treatment reagents such as ethylene carbonate, dimercaptothiadiazoles, or molybdenum trioxide.

Low Metal Content

Copolymers may have metal content due to catalysts used in their production. Low metal content copolymers are desirable due to the harmful effects of metals in various environments. For example, metals can have an adverse impact on after-treatment devices employed in various types of engines. It is also desirable to ensure that the copolymers have low fluorine content since fluorine is ecologically undesirable in many environments.

There are several methods to achieve a low metal content in the copolymer as described herein. The present invention incorporates methods known by those skilled in the art to purify and remove impurities. For example, in Giuseppe Forte and Sara Ronca, “Synthesis of Disentangled Ultra-High Molecular Weight Polyethylene: Influence of Reaction Medium on Material Properties,” International Journal of Polymer Science, vol. 2017, Article ID 7431419, 8 pages, 2017. doi:10.1155/2017/7431419, methods for purifying a polyethylene compound are disclosed. The method of purifying the copolymer comprises dissolving the copolymer in acidified methanol (CH₃OH/HCl) to a DCM (dichloromethane) solution of the polymer/catalyst mixture. This results in precipitation of the “purified” polymer, while the catalyst and other byproducts remain in solution. The copolymer may then be filtered and washed out with additional methanol, and oven dried under vacuum at 40° C.

According to one or more embodiments, the copolymer may be purified to achieve low metal content by passing the polymer/catalyst mixture through an adsorption column. The adsorption column contains an adsorber, preferably, activated alumina.

In another embodiment, the copolymer may be purified to achieve low metal content by stripping the polymer compositions using toluene and a rotary evaporator with a temperature-controlled oil bath.

In some embodiments, the copolymer does not require a purification step. In this embodiment, the olefin copolymer is obtained by copolymerization using a catalyst having a catalyst productivity of from 200-1500 kg copolymer/gram of single-site catalyst, or from 350-1500 kg copolymer/gram of single-site catalyst, or from 500-1200 kg copolymer/gram of single-site catalyst, or from 500-800 kg copolymer/gram of single-site catalyst. Suitable single-site catalyst systems having these productivities may be selected from those known in the art. The catalysts may be selected for the production of copolymers having Mn in the range of 700-1400 g/mol, or from 550-650 g/mol. Selection of a suitable single-site catalyst may eliminates the need for a wash step to achieve the low metal content of the copolymer.

Catalyst productivity, expressed as the kg polymer produced per gram of catalyst, may be improved by efficient catalyst systems. The present invention incorporates the use of catalyst systems known by those skilled in the art which are capable of achieving high catalyst productivities. For example, U.S. Pat. No. 9,441,063 relates to catalyst compositions containing activator-supports and half-metallocene titanium phosphinimide complexes or half-metallocene titanium iminoimidazolidides capable of producing polyolefins with high catalyst productivities of at least up to 202 kg polymer/g catalyst (551 kg polymer/g cat/hr with a 22 min residence time, See Example 5 and Table 1, Columns 47 and 48.) Also, U.S. Pat. No. 8,614,277 relates to methods for preparing isotactic polypropylene and ethylene-propylene copolymers. U.S. Pat. No. 8,614,277 provides catalyst systems suitable for preparing copolymers at catalyst productivity levels greater than 200 kg polymer/g catalyst. The catalysts provided therein are metallocenes comprising zirconium as their central atom. (See the examples in Tables 1a-1c).

The copolymer may comprise a metal content of 25 ppmw or less, based on the total weight of the copolymer. Preferably, the metal content of the copolymer is 10 ppmw or less, or more preferably 5 ppmw or less, or even more preferably 1 ppmw or less, based on the total weight of the copolymer. Typically, the metal content of the copolymer is derived from the single-site catalyst and optional co-catalyst(s) employed in the copolymerization reactor.

These single-site catalysts may include metallocene catalysts. Zr and Ti metals are typically derived from such metallocene catalysts. Various co-catalysts may be employed in combination with the single-site catalyst. Such co-catalysts may include boron and aluminum metals, as well as ecologically undesirable fluorine atoms or compounds. Thus, the metal content of the copolymers of the present invention is the total metal including Zr, Ti, Al and/or B.

The copolymers may have a fluorine content of less than 10 ppmw, or less than 8 ppmw, or less than 5 ppmw, based on the total weight of the copolymer. Typically, the fluorine will come from co-catalyst systems based on boron compounds such as pefluoroaryl boranes.

Lubricating Oil Compositions

The olefin copolymer dispersants described herein may be blended to a major amount of a base oil in combination with one or more further additives to produce a lubricating oil composition that has a reduced or low boundary friction coefficient and also has positive low temperature viscosity characteristics. The lubricating oil compositions herein may include about 0.1 wt % to about 15 wt %, or about 0.1 wt % to about 10 wt %, or about 3 wt % to about 10 wt %, or about 1 wt % to about 6 wt %, or about 7 wt % to about 12 wt %, of the olefin copolymer dispersant, based upon the weight of the lubricant composition. In some embodiments, the lubricant composition utilizes a mixed dispersant system in combination with one or more further additives.

Phosphorus-Containing Compounds

The lubricant composition herein may comprise one or more phosphorus-containing compounds that may impart anti-wear benefits to the fluid. The one or more phosphorus-containing compounds may be present in the lubricating oil composition in an amount ranging from about 0 wt % to about 15 wt %, or about 0.01 wt % to about 10 wt %, or about 0.05 wt % to about 5 wt %, or about 0.1 wt % to about 3 wt % of the lubricating oil composition. The phosphorus-containing compound may provide up to 5000 ppm phosphorus, or from about 50 to about 5000 ppm phosphorus, or from about 300 to about 1500 ppm phosphorus, or up to 600 ppm phosphorus, or up to 900 ppm phosphorus to the lubricant composition.

The one or more phosphorus-containing compounds include metal containing phosphorus-containing compounds and/or ashless phosphorus-containing compounds. Examples of suitable phosphorus-containing compound include, but are not limited to, thiophosphates, dithiophosphates, metal phosphates, metal thiophosphates, metal dithiophosphates, phosphates, phosphoric acid esters, phosphate esters, phosphites, phosphonates, phosphorus-containing carboxylic esters, ethers, or amides salts thereof, and mixtures thereof. Phosphorus containing anti-wear agents are more fully described in European Patent 0612839.

It should be noted that often the term phosphonate and phosphite are used often interchangeably in the lubricant industry. For example, dibutyl hydrogen phosphonate is often referred to as dibutyl hydrogen phosphite. It is within the scope of the present invention for the inventive lubricant composition to include a phosphorus-containing compound that may be referred to as either a phosphite or a phosphonate.

In any of the above described phosphorus-containing compounds, the compound may have about 5 to about 20 weight percent phosphorus, or about 5 to about 15 weight percent phosphorus, or about 8 to about 16 weight percent phosphorus, or about 6 to about 9 weight percent phosphorus.

The inclusion of the phosphorus-containing compound in combination with the above described dispersant to a lubricant compositions unexpectedly imparts positive frictional characteristics, such as a low friction coefficient, to the lubricant composition. The inventive effect is even further pronounced in some cases where the phosphorus-containing compound, on its own, imparts negative frictional characteristics to the fluid. When these relatively poor friction reducing phosphorus-containing compounds are combined with the olefin copolymer dispersant described herein, the lubricant composition has an improved, i.e., lower, friction coefficient. That is, the dispersants herein tend to transform fluids containing phosphorus-containing compounds having relatively poor friction coefficients into fluids with improved frictional properties.

This improvement in frictional properties of the lubricating compositions including the phosphorus-containing compounds and the olefin copolymer dispersant described herein is surprising because the frictional properties of the fluid are better than combinations of the phosphorus-containing compounds in combination with other types of dispersants, including polyisobutylene succinimide dispersants and olefin copolymer succinimide dispersants that do not have the specified characteristics of the copolymers described above.

One type of phosphorus-containing compound that when combined with the dispersant herein imparts improved frictional characteristics to a lubricating composition is a metal dihydrocarbyl dithiophosphate compound, such as but not limited to, a zinc dihydrocarbyl dithiophosphate compound (ZDDP). When the phosphorus-containing compound is a metal thiophosphate or metal dithiophosphate, such as ZDDP, it may include between 5 to about 10 weight percent metal, about 6 to about 9 weight percent metal, about 8 to 18 weight percent sulfur, about 12 to about 18 weight percent sulfur, or about 8 to about 15 weight percent sulfur. Suitable metal dihydrocarbyl dithiophosphates may comprise dihydrocarbyl dithiophosphate metal salts wherein the metal may be an alkali metal, alkaline earth metal, aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium, zirconium, zinc, or combinations thereof.

When the phosphorus-containing compound is a ZDDP, the alkyl groups on ZDDP may be derived from primary alcohols, secondary alcohols, phenols, and/or mixtures thereof. For example, all of the alkyl groups of ZDDP may be derived from a secondary alcohol such as methyl isobutyl carbinol, or from a mixture of secondary alcohols such as methyl isobutyl carbinol and isopropyl alcohol. In some cases, the alkyl groups of the ZDDP may be derived from a mixture of primary and secondary alcohols, such as 2-ethyl hexanol, isobutanol, and isopropanol. For example, in one embodiment, about 20% of the alkyl groups are derived from 2-ethyl hexanol, about 40% of the alkyl groups are derived from isobutanol, and about 40% of the alkyl groups are derived from isopropanol. In other embodiments, all of the alkyl groups on the ZDDP may be derived from a primary alcohol, such as 2-ethyl hexanol. ZDDPs may include about 6 to about 10 weight percent phosphorus, about 6 to about 9 weight percent zinc, and about 12 to about 18 weight percent sulfur.

Examples of such ZDDPs include, but are not limited to: zinc O,O-di(C_1-14-alkyl)dithiophosphate; zinc (mixed O,O-bis(sec-butyl and isooctyl)) dithiophosphate; zinc-O,O-bis(branched and linear C_3-8-alkyl)dithiophosphate; zinc O,O-bis(2-ethylhexyl)dithiophosphate; zinc O,O-bis(mixed isobutyl and pentyl)dithiophosphate; zinc mixed O,O-bis(1,3-dimethylbutyl and isopropyl)dithiophosphate; zinc O,O-diisooctyl dithiophosphate; zinc O,O-dibutyl dithiophosphate; zinc mixed O,O-bis(2-ethylhexyl and isobutyl and isopropyl)dithiophosphate; zinc O,O-bis(dodecylphenyl)dithiophosphate; zinc O,O-diisodecyl dithiophosphate; zinc O-(6-methylheptyl)-O-(1-methylpropyl)dithiophosphate; zinc O-(2-ethylhexyl)-O-(isobutyl)dithiophosphate; zinc O,O-diisopropyl dithiophosphate; zinc (mixed hexyl and isopropyl)dithiophosphate; zinc (mixed O-(2-ethylhexyl) and O-isopropyl) dithiophosphate; zinc O,O-dioctyl dithiophosphate; zinc O,O-dipentyl dithiophosphate; zinc O-(2-methylbutyl)-O-(2-methylpropyl)dithiophosphate; and zinc O-(3-methylbutyl)-O-(2-methylpropyl)dithiophosphate.

The phosphorus-containing compound may have the formula:

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wherein R in Formula XIII independently contains from 1 to 18 carbon atoms, or 2 to 12 carbon atoms, or about 3 to 8 carbon atoms. For example, R may be ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, amyl, n-hexyl, i-hexyl, n-octyl, decyl, dodecyl, octadecyl, 2-ethylhexyl, phenyl, butylphenyl, cyclohexyl, methylcyclopentyl, propenyl, butenyl. The number of carbon atoms in each R group in the formula above will generally be about 3 or greater, about 4 or greater, about 6 or greater, or about 8 or greater. Each R group may average 3 to 8 carbons. The total number of carbon atoms in the R groups may be 5 to about 72, or 12 to about 32. In Formula XIII, A is a metal, such as aluminum, lead, tin, molybdenum, manganese, nickel, copper, titanium, zirconium, zinc, or combinations thereof. When the phosphorus-containing compound has the structure shown in Formula XIII, the compound may have about 6 to about 9 weight percent phosphorus.

In some embodiments, the phosphorous-containing compound of the present invention has the structure of Formula XIII wherein A is zinc and the compound provides between 70-800 ppm phosphorus to the lubricant composition.

It is understood in the art that a more accurate representation of the sulfur-zinc coordination arrangement may be represented by the symmetrical arrangement shown below the chemical structure of Formula XIII used herein is interchangeable with Formula XIII′ shown below. It is also understood that the structures shown in Formulas XIII and XIII′ may be present as monomer, dimer, trimer, or oligomer (such as a tetramer).

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Dihydrocarbyl dithiophosphate metal salts may be prepared in accordance with known techniques by first forming a dihydrocarbyl dithiophosphoric acid (DDPA), usually by reaction of one or more alcohols or phenols with P₂S₅and then neutralizing the formed DDPA with a metal compound, such as zinc oxide. For example, DDPA may be made by reacting mixtures of primary and secondary alcohols with P₂S₅. In this case, the DDPA includes alkyl groups derived from both primary and secondary alcohols. Alternatively, multiple DDPAs can be prepared where the alkyl groups on one DDPA are derived entirely from secondary alcohols and the alkyl groups on another DDPA are derived entirely from primary alcohols. The DDPAs are then blended together to form a mixture of DDPAs having alkyl groups derived from both primary and secondary alcohols.

To make the metal salt, any basic or neutral metal compound could be used but the oxides, hydroxides and carbonates are most generally employed. Commercial additives frequently contain an excess of metal due to the use of an excess of the basic metal compound in the neutralization reaction.

Another type of phosphorus-containing compound that when combined with the olefin copolymer dispersant herein imparts improved frictional characteristics to a lubricating composition is an ashless (metal free) phosphorus-containing compound.

In some embodiments, the ashless phosphorus-containing compound may be dialkyl dithiophosphate ester, amyl acid phosphate, diamyl acid phosphate, dibutyl hydrogen phosphonate, dimethyl octadecyl phosphonate, salts thereof, and mixtures thereof.

The ashless phosphorus-containing compound may be have the formula:

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wherein R₁is S or O; R₂is —OR″, —OH, or —R″; R₃is —OR″, —OH, or SR′″C(O)OH; R₄is —OR″; R′″ is C₁to C₃branched or linear alkyl chain; and R″ is a C1 to C18 hydrocarbyl chain. When the phosphorous-containing compound has the structure shown in Formula XIV, the compound may have about 8 to about 16 weight percent phosphorus.

In some embodiments the lubricant composition comprises a phosphorus-containing compound of Formula XIV wherein R₁is S; R₂is —OR″; R₃is S R′″COOH; R₄is —OR″; R′″ is C₃branched alkyl chain; R″ is C₄; and wherein the phosphorus-containing compound is present in an amount to deliver between 80-900 ppm phosphorus to the lubricant composition.

In another embodiment, the lubricant composition comprises a phosphorus-containing compound of Formula XIV wherein R₁is O; R₂is —OH; R₃is —OR″ or —OH; R₄is —OR″; R″ is C₅; and wherein phosphorus-containing compound is present in an amount to deliver between 80-1500 ppm phosphorus to the lubricant composition.

In yet another embodiment, the lubricant composition comprises a phosphorus-containing compound of Formula XIV wherein R₁is O; R₂is OR″; R₃is H; R₄is —OR″; R″ is C₄; and wherein the one or more phosphorus-containing compound(s) is present in an amount to deliver between 80-1550 ppm phosphorus to the lubricant composition.

In other embodiments, the lubricant composition comprises a phosphorus-containing compound of Formula XIV wherein R₁is O; R₂is —R″; R₃is —OCH₃or —OH; R₄is —OCH₃; R″ is C₁₈; and wherein the one or more phosphorus-containing compound(s) is present in an amount to deliver between 80-850 ppm phosphorus to the lubricant composition.

In some embodiments, the phosphorus-containing compound has the structure shown in Formula XIV and delivers about 80 to about 4500 ppm phosphorus to the lubricant composition. In other embodiments, the phosphorus-containing compound is present in an amount to deliver between about 150 and about 1500 ppm phosphorus, or between about 300 and about 900 ppm phosphorus, or between about 800 to 1600 ppm phosphorus, or about 900 to about 1800 ppm phosphorus, to the lubricant composition.

Additional Anti-Wear Agents

The lubricant composition may also include additional anti-wear agents that are non-phosphorus-containing compounds. Examples of such antiwear agents include borate esters, borate epoxides, thiocarbamate compounds (including thiocarbamate esters, alkylene-coupled thiocarbamates, and bis(S-alkyldithiocarb amyl)disulfides, thiocarbamate amides, thiocarbamic ethers, alkylene-coupled thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides, and mixtures thereof), sulfurized olefins, tridecyl adipate, titanium compounds, and long chain derivatives of hydroxyl carboxylic acids, such as tartrate derivatives, tartramides, tartrimides, citrates, and mixtures thereof. A suitable thiocarbamate compound is molybdenum dithiocarbamate. Suitable tartrate derivatives or tartrimides may contain alkyl-ester groups, where the sum of carbon atoms on the alkyl groups may be at least 8. The tartrate derivative or tartrimide may contain alkyl-ester groups, where the sum of carbon atoms on the alkyl groups may be at least 8. The antiwear agent may in one embodiment include a citrate. The additional anti-wear agent may be present in ranges including about 0 wt % to about 15 wt %, or about 0.01 wt % to about 10 wt %, or about 0.05 wt % to about 5 wt %, or about 0.1 wt % to about 3 wt % of the lubricating oil composition.

Detergents

The lubricant composition may optionally further comprise one or more neutral, low based, or overbased detergents, and mixtures thereof.

Suitable detergent substrates include phenates, sulfur-containing phenates, sulfonates, calixarates, salixarates, salicylates, carboxylic acids, phosphorus acids, mono- and/or di-thiophosphoric acids, alkyl phenols, sulfur coupled alkyl phenol compounds, or methylene bridged phenols. Suitable detergents and their methods of preparation are described in greater detail in numerous patent publications, including U.S. Pat. No. 7,732,390 and references cited therein. The detergent substrate may be salted with an alkali or alkaline earth metal such as, but not limited to, calcium, magnesium, potassium, sodium, lithium, barium, zinc, or mixtures thereof.

A suitable detergent may include alkali or alkaline earth metal salts, e.g., calcium or magnesium, of petroleum sulfonic acids and long chain mono- or di-alkylaryl sulfonic acids with the aryl group being benzyl, tolyl, and xylyl. Examples of other suitable detergents include, but are not limited to low-based/neutral and overbased variations of the following detergents: calcium phenates, calcium sulfur containing phenates, calcium sulfonates, calcium calixarates, calcium salixarates, calcium salicylates, calcium carboxylic acids, calcium phosphorus acids, calcium mono- and/or di-thiophosphoric acids, calcium alkyl phenols, calcium sulfur coupled alkyl phenol compounds, calcium methylene bridged phenols, magnesium phenates, magnesium sulfur containing phenates, magnesium sulfonates, magnesium calixarates, magnesium salixarates, magnesium salicylates, magnesium carboxylic acids, magnesium phosphorus acids, magnesium mono- and/or di-thiophosphoric acids, magnesium alkyl phenols, magnesium sulfur coupled alkyl phenol compounds, magnesium methylene bridged phenols, sodium phenates, sodium sulfur containing phenates, sodium sulfonates, sodium calixarates, sodium salixarates, sodium salicylates, sodium carboxylic acids, sodium phosphorus acids, sodium mono- and/or di-thiophosphoric acids, sodium alkyl phenols, sodium sulfur coupled alkyl phenol compounds, or sodium methylene bridged phenols.

The detergent may be present at about 0 wt % to about 10 wt %, or about 0.1 wt % to about 8 wt %, or about 1 wt % to about 4 wt %, or greater than about 4 wt % to about 8 wt %. In other approaches, the detergent may be provided in the lubricating oil composition in an amount to provide about 450 to about 2200 ppm metal to the lubricant composition and to deliver a soap content of about 0.4 to about 1.5 weight percent to the lubricant composition. In other approaches, the detergent is in an amount to provide about 450 to about 2200 ppm metal to the lubricant composition and to deliver a soap content of about 0.4 to about 0.7 weight percent to the lubricant composition.

Overbased detergent additives are well-known in the art and may be alkali or alkaline earth metal overbased detergent additives. Such detergent additives may be prepared by reacting a metal oxide or metal hydroxide with a substrate and carbon dioxide gas. The substrate is typically an acid, for example, an acid such as an aliphatic substituted sulfonic acid, an aliphatic substituted carboxylic acid, or an aliphatic substituted phenol.

The term “overbased” relates to metal salts, such as metal salts of sulfonates, carboxylates, salicylates and/or phenates, wherein the amount of metal present exceeds the stoichiometric amount. Such salts may have a conversion level in excess of 100% (i.e., they may comprise more than 100% of the theoretical amount of metal needed to convert the acid to its “normal,” “neutral” salt). The expression “metal ratio,” often abbreviated as MR, is used to designate the ratio of total chemical equivalents of metal in the overbased salt to chemical equivalents of the metal in a neutral salt according to known chemical reactivity and stoichiometry. In a normal or neutral salt, the MR is one and in an overbased salt, MR, is greater than one. They are commonly referred to as overbased, hyperbased, or superbased salts and may be salts of organic sulfur acids, carboxylic acids, or phenols.

As used herein, the term “TBN” is used to denote the Total Base Number in mg KOH/g as measured by the method of ASTM D2896. An overbased detergent of the lubricating oil composition may have a total base number (TBN) of about 200 mg KOH/gram or greater, or about 250 mg KOH/gram or greater, or about 350 mg KOH/gram or greater, or about 375 mg KOH/gram or greater, or about 400 mg KOH/gram or greater. The overbased detergent may have a metal to substrate ratio of from 1.1:1, or from 2:1, or from 4:1, or from 5:1, or from 7:1, or from 10:1.

Examples of suitable overbased detergents include, but are not limited to, overbased calcium phenates, overbased calcium sulfur containing phenates, overbased calcium sulfonates, overbased calcium calixarates, overbased calcium salixarates, overbased calcium salicylates, overbased calcium carboxylic acids, overbased calcium phosphorus acids, overbased calcium mono- and/or di-thiophosphoric acids, overbased calcium alkyl phenols, overbased calcium sulfur coupled alkyl phenol compounds, overbased calcium methylene bridged phenols, overbased magnesium phenates, overbased magnesium sulfur containing phenates, overbased magnesium sulfonates, overbased magnesium calixarates, overbased magnesium salixarates, overbased magnesium salicylates, overbased magnesium carboxylic acids, overbased magnesium phosphorus acids, overbased magnesium mono- and/or di-thiophosphoric acids, overbased magnesium alkyl phenols, overbased magnesium sulfur coupled alkyl phenol compounds, or overbased magnesium methylene bridged phenols.

The overbased detergent may comprise at least 97.5 wt % of the total detergent in the lubricating oil composition. In some embodiments, at least 96 wt %, or at least 94 wt %, or at least 92 wt %, or at least 90 wt % or at least 88 wt % or at least 80 wt % of the total detergent in the lubricating oil composition is overbased detergent.

The low-based/neutral detergent has a TBN of up to 175 mg KOH/g, or up to 150 mg KOH/g. The low-based/neutral detergent may include a calcium or magnesium-containing detergent. Examples of suitable low-based/neutral detergent include, but are not limited to, calcium sulfonates, calcium phenates, calcium salicylates, magnesium sulfonates, magnesium phenates, and magnesium salicylates. In some embodiments, the low-based/neutral detergent is a mixture of calcium-containing detergents and or magnesium-containing detergents.

The low-based/neutral detergent may comprise at least 2.5 wt % of the total detergent in the lubricating oil composition. In some embodiments, at least 4 wt %, or at least 6 wt %, or at least 8 wt %, or at least 10 wt % or at least 12 wt % or at least 20 wt % of the total detergent in the lubricating oil composition is a low-based/neutral detergent which may optionally be a low-based/neutral calcium-containing detergent.

In certain embodiments, the one or more low-based/neutral detergents provide from about 50 to about 1000 ppm calcium or magnesium by weight to the lubricating oil composition based on a total weight of the lubricating oil composition. In some embodiments, the one or more low-based/neutral calcium-containing detergents provide from 75 to less than 800 ppm, or from 100 to 600 ppm, or from 125 to 500 ppm by weight calcium or magnesium to the lubricant composition based on a total weight of the lubricant composition.

Extreme Pressure Agents

The lubricant compositions of the disclosure may also contain at least one extreme pressure agent. The extreme pressure agent may contain sulfur and may contain at least 12 percent by weight sulfur. In some embodiments, the extreme pressure agent added to the lubricating oil is sufficient to provide at least 350 ppm sulfur, 500 ppm sulfur, 760 ppm sulfur, from about 350 to about 2,000 ppm sulfur, from about 2,000 to about 30,000 ppm sulfur, or from about 2,000 to about 4,800 ppm sulfur, or about 4,000 to about 25,000 ppm sulfur to the lubricant composition.

A wide variety of sulfur-containing extreme pressure agents are suitable and include sulfurized animal or vegetable fats or oils, sulfurized animal or vegetable fatty acid esters, fully or partially esterified esters of trivalent or pentavalent acids of phosphorus, sulfurized olefins (see, for example U.S. Pat. Nos. 2,995,569; 3,673,090; 3,703,504; 3,703,505; 3,796,661; 3,873,454 4,119,549; 4,119,550; 4,147,640; 4,191,659; 4,240,958; 4,344,854; 4,472,306; and 4,711,736), dihydrocarbyl polysulfides (see for example U.S. Pat. Nos. 2,237,625; 2,237,627; 2,527,948; 2,695,316; 3,022,351; 3,308,166; 3,392,201; 4,564,709; and British 1,162,334), functionally-substituted dihydrocarbyl polysulfides (see for example U.S. Pat. No. 4,218,332), and polysulfide olefin products (see for example U.S. Pat. No. 4,795,576). Other suitable examples include organo-sulfur compounds selected from sulfurized olefins, sulfur-containing amino heterocyclic compounds, 5-dimercapto-1,3,4-thiadiazole, polysulfides having a majority of S₃and S₄sulfides, sulfurized fatty acids, sulfurized branched olefins, organic polysulfides, and mixtures thereof.

In some embodiments the extreme pressure agent is present in the lubricating composition in an amount of up to about 3.0 wt % or up to about 5.0 wt %. In other embodiments, the extreme pressure agent is present from about 0.05 wt % to about 0.5 wt %, based on the total lubricant composition. In other embodiments, the extreme pressure agent is present from about 0.1 wt % to about 3.0 wt %, based on the total lubricant composition. In other embodiments the extreme pressure agent is present in an amount between about 0.6 wt % and about 1 wt %, based on the total lubricant composition. In yet other embodiments, the detergent is present in an amount of about 1.0 wt %, based on the total lubricant composition.

One suitable class of extreme pressure agents are polysulfides composed of one or more compounds represented by the formula: R_a—S_x—R_bwhere R_aand R_bare hydrocarbyl groups each of which may contain 1 to 18, and in other approaches, 3 to 18 carbon atoms and x is may be in the range of from 2 to 8, and typically in the range of from 2 to 5, especially 3. In some approaches, x is an integer from 3 to 5 with about 30 to about 60 percent of x being an integer of 3 or 4. The hydrocarbyl groups can be of widely varying types such as alkyl, cycloalkyl, alkenyl, aryl, or aralkyl. Tertiary alkyl polysulfides such as di-tert-butyl trisulfide, and mixtures comprising di-tert-butyl trisulfide (e.g., a mixture composed principally or entirely of the tri, tetra-, and pentasulfides) may be used. Examples of other useful dihydrocarbyl polysulfides include the diamyl polysulfides, the dinonyl polysulfides, the didodecyl polysulfides, and the dibenzyl polysulfides.

Another suitable class of extreme pressure agent is sulfurized isobutenes made by reacting an olefin, such as isobutene, with sulfur. Sulfurized isobutene (SIB), notably sulfurized polyisobutylene, typically has a sulfur content of from about 10 to about 55%, desirably from about 30 to about 50% by weight. A wide variety of other olefins or unsaturated hydrocarbons, e.g., isobutene dimer or trimer, may be used to form the sulfurized olefin extreme pressure agents. Various methods have been disclosed in the prior art for the preparation of sulfurized olefins. See, for example, U.S. Pat. No. 3,471,404 to Myers; U.S. Pat. No. 4,204,969 to Papay et al.; U.S. Pat. No. 4,954,274 to Zaweski et al.; U.S. Pat. No. 4,966,720 to DeGonia et al.; and U.S. Pat. No. 3,703,504 to Horodysky, et al, each of which his incorporated herein by reference.

Methods for preparing sulfurized olefins, including the methods disclosed in the aforementioned patents, generally involve formation of a material, typically referred to as an “adduct”, in which an olefin is reacted with a sulfur halide, for example, sulfur monochloride. The adduct is then reacted with a sulfur source to provide the sulfurized olefin. The quality of a sulfurized olefin is generally measured by various physical properties, including, for example, viscosity, sulfur content, halogen content and copper corrosion test weight loss. U.S. Pat. No. 4,966,720, relates to sulfurized olefins useful as extreme pressure additives in lubrication oils and to a two stage reaction for their preparation.

Friction Modifiers

The lubricating oil compositions herein also may optionally contain one or more friction modifiers, such as friction modifiers selected from organic ashless nitrogen-free friction modifiers, organic ashless aminic friction modifiers, inorganic friction modifiers, and mixtures thereof. Suitable friction modifiers may also include metal containing and metal-free friction modifiers and may include, but are not limited to, imidazolines, amides, amines, succinimides, alkoxylated amines, alkoxylated ether amines, amine oxides, amidoamines, nitriles, betaines, quaternary amines, imines, amine salts, amino guanidine, alkanolamides, phosphonates, metal-containing compounds, glycerol esters, borated glycerol esters, partial esters of glycerol such as glycerol monooleate, fatty phosphites, fatty epoxides, sulfurized fatty compounds and olefins, sunflower oil other naturally occurring plant or animal oils, dicarboxylic acid esters, esters or partial esters of a polyol, one or more aliphatic or aromatic carboxylic acids, and the like. A friction modifier may optionally be included in the lubricating oil compositions herein in ranges from about 0 wt % to about 10 wt %, or about 0.01 wt % to about 8 wt %, or about 0.1 wt % to about 4 wt %.

Suitable friction modifiers may contain hydrocarbyl groups that are selected from straight chain, branched chain, or aromatic hydrocarbyl groups or mixtures thereof, and may be saturated or unsaturated. The hydrocarbyl groups may be composed of carbon and hydrogen or hetero atoms such as sulfur or oxygen. The hydrocarbyl groups may range from about 12 to about 25 carbon atoms. In some embodiments the friction modifier may be a long chain fatty acid ester. In another embodiment the long chain fatty acid ester may be a mono-ester, or a di-ester, or a (tri)glyceride. The friction modifier may be a long chain fatty amide, long chain fatty amine, a long chain fatty ester, a long chain fatty epoxide derivative, or a long chain imidazoline.

Other suitable friction modifiers may include organic, ashless (metal-free), nitrogen-free organic friction modifiers. Such friction modifiers may include esters formed by reacting carboxylic acids and anhydrides with alkanols and generally include a polar terminal group (e.g. carboxyl or hydroxyl) covalently bonded to an oleophilic hydrocarbon chain. An example of an organic ashless nitrogen-free friction modifier is known generally as glycerol monooleate (GMO) which may contain mono-, di-, and tri-esters of oleic acid. Other suitable friction modifiers are described in U.S. Pat. No. 6,723,685, herein incorporated by reference in its entirety.

Aminic friction modifiers may include amines or polyamines. Such compounds can have hydrocarbyl groups that are linear, either saturated or unsaturated, or a mixture thereof and may contain from about 12 to about 25 carbon atoms. Further examples of suitable friction modifiers include alkoxylated amines and alkoxylated ether amines. Such compounds may have hydrocarbyl groups that are linear, either saturated, unsaturated, or a mixture thereof. They may contain from about 12 to about 25 carbon atoms. Examples include ethoxylated amines and ethoxylated ether amines.

The amines and amides may be used as such or in the form of an adduct or reaction product with a boron compound such as a boric oxide, boron halide, metaborate, boric acid or a mono-, di- or tri-alkyl borate. Other suitable friction modifiers are described in U.S. Pat. No. 6,300,291, herein incorporated by reference in its entirety.

Suitable friction modifiers include glycerides, fatty acids, glycerol monooleate, fatty alkyl tartrate derivatives, imidazolines, alkoxy amines, alkyl fatty amines, acyl glycines, cerium nanoparticles, titanium-containing compounds, molybdenum-containing compounds, and mixtures thereof. The titanium-containing compound may be a reaction product of titanium alkoxide and neodecanoic acid. The cerium nanoparticle may be obtained from the reaction product of an organo-cerium salt, a fatty acid, and an amine in the substantial absence of water and organic solvent at a temperature from about 150° C. to about 250° C. The cerium nanoparticles may have a particle size less than about 10 nanometers. Suitable fatty acids may be those including C₁₀to C₃₀saturated, monounsaturated, or polyunsaturated carboxylic acid and the amine is a fatty amine selected from C₈to C₃₀saturated or unsaturated amines.

In some approaches, the friction modifier may be a glycerides having the formula

embedded image

wherein each R₂₀is independently selected from the group consisting of H and —C(O)R′″ wherein R′″ may be a saturated or an unsaturated alkyl group having from 3 to 23 carbon atoms.

The friction modifier may also be imidazolines having the formula

embedded image

wherein R₂₁is an alkyl or alkenyl group containing from about 10 to about 30 carbon atoms and R₂₂is a hydroxyalkyl group containing from about 2 to about 4 carbon atoms.

The friction modifier may also be alkoxy amines including an N-aliphatic hydrocarbyl-substituted diethanolamine in which the N-aliphatic hydrocarbyl-substituent is at least one straight chain aliphatic hydrocarbyl group free of acetylenic unsaturation and having 14 to 20 carbon atoms.

The friction modifier may further be an alkyl fatty amines include aliphatic primary fatty amines selected from n-hexylamine, n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-octadecylamine, and mixtures thereof;

The friction modifier may be an acyl glycine and have the formula

embedded image

wherein R₂₃is a linear or branched, saturated, unsaturated, or partially saturated hydrocarbyl having about 8 to about 22 carbon atoms and R₂₄is hydrogen, a hydrocarbyl having 1 to 8 carbon atoms, or a C₁to C₈hydrocarbyl group containing one or more heteroatoms.

Antioxidants

The lubricating oil compositions herein also may optionally contain one or more antioxidants. Antioxidant compounds are known and include for example, phenates, phenate sulfides, sulfurized olefins, phosphosulfurized terpenes, sulfurized esters, aromatic amines, alkylated diphenylamines (e.g., nonyl diphenylamine, di-nonyl diphenylamine, octyl diphenylamine, di-octyl diphenylamine), phenyl-alpha-naphthylamines, alkylated phenyl-alpha-naphthylamines, hindered non-aromatic amines, phenols, hindered phenols, oil-soluble molybdenum compounds, macromolecular antioxidants, or mixtures thereof. Antioxidant compounds may be used alone or in combination.

The hindered phenol antioxidant may contain a secondary butyl and/or a tertiary butyl group as a sterically hindering group. The phenol group may be further substituted with a hydrocarbyl group and/or a bridging group linking to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol, or 4-dodecyl-2,6-di-tert-butylphenol. In one embodiment the hindered phenol antioxidant may be an ester and may include, e.g., Irganox® L-135 available from BASF or an addition product derived from 2,6-di-tert-butylphenol and an alkyl acrylate, wherein the alkyl group may contain about 1 to about 18, or about 2 to about 12, or about 2 to about 8, or about 2 to about 6, or about 4 carbon atoms. Another commercially available hindered phenol antioxidant may be an ester and may include Ethanox® 4716 available from Albemarle Corporation.

Useful antioxidants may include diarylamines and phenols. In an embodiment, the lubricating oil composition may contain a mixture of a diarylamine and a phenol, such that each antioxidant may be present in an amount sufficient to provide up to about 5 wt %, based on the weight of the lubricant composition. In an embodiment, the antioxidant may be a mixture of about 0.3 to about 1.5 wt % diarylamine and about 0.4 to about 2.5 wt % phenol, based on the lubricant composition.

Examples of suitable olefins that may be sulfurized to form a sulfurized olefin include propylene, butylene, isobutylene, polyisobutylene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene or mixtures thereof. In one embodiment, hexadecene, heptadecene, octadecene, nonadecene, eicosene or mixtures thereof and their dimers, trimers and tetramers are especially useful olefins. Alternatively, the olefin may be a Diels-Alder adduct of a diene such as 1,3-butadiene and an unsaturated ester, such as, butylacrylate.

Another class of sulfurized olefin includes sulfurized fatty acids and their esters. The fatty acids are often obtained from vegetable oil or animal oil and typically contain about 4 to about 22 carbon atoms. Examples of suitable fatty acids and their esters include triglycerides, oleic acid, linoleic acid, palmitoleic acid or mixtures thereof. Often, the fatty acids are obtained from lard oil, tall oil, peanut oil, soybean oil, cottonseed oil, sunflower seed oil or mixtures thereof. Fatty acids and/or ester may be mixed with olefins, such as α-olefins.

The one or more antioxidant(s) may be present in ranges about 0 wt % to about 20 wt %, or about 0.1 wt % to about 10 wt %, or about 1 wt % to about 5 wt %, of the lubricating oil composition.

Boron-Containing Compounds

The lubricant composition herein may optionally contain one or more boron-containing compounds. Examples of boron-containing compounds include borate esters, borated fatty amines, borated epoxides, borated detergents, and borated dispersants, such as borated succinimide dispersants, as disclosed in U.S. Pat. No. 5,883,057. The boron-containing compound, if present, can be used in an amount sufficient to provide the lubricant composition with a boron level of up to about 3000 ppm, about 5 ppm to about 2000 ppm, about 15 ppm to about 600 ppm, about 20 ppm to about 400 ppm, about 70 ppm to about 300 ppm.

Additional Dispersants

Additional dispersants contained in the lubricant composition may include, but are not limited to, an oil soluble polymeric hydrocarbon backbone having functional groups that are capable of associating with particles to be dispersed. Typically, the dispersants comprise amine, alcohol, amide, or ester polar moieties attached to the polymer backbone often via a bridging group. Dispersants may be selected from Mannich dispersants as described in U.S. Pat. Nos. 3,634,515, 3,697,574 and 3,736,357; ashless succinimide dispersants as described in U.S. Pat. Nos. 4,234,435 and 4,636,322; amine dispersants as described in U.S. Pat. Nos. 3,219,666, 3,565,804, and 5,633,326; Koch dispersants as described in U.S. Pat. Nos. 5,936,041, 5,643,859, and 5,627,259, and polyalkylene succinimide dispersants as described in U.S. Pat. Nos. 5,851,965; 5,853,434; and 5,792,729.

In some embodiments, the additional dispersant may be derived from a polyalphaolefin (PAO) succinic anhydride, an olefin maleic anhydride copolymer. As an example, the additional dispersant may be described as a poly-PIBSA. In another embodiment, the additional dispersant may be derived from an anhydride which is grafted to an ethylene-propylene copolymer. Another additional dispersant may be a high molecular weight ester or half ester amide.

The additional dispersant, if present, can be used in an amount sufficient to provide up to about 10 wt %, based upon the final weight of the lubricating oil composition. Another amount of the dispersant that can be used may be about 0.1 wt % to about 10 wt %, or about 0.1 wt % to about 10 wt %, or about 3 wt % to about 8 wt %, or about 1 wt % to about 6 wt %, based upon the final weight of the lubricating oil composition.

Molybdenum-Containing Compounds

The lubricating oil compositions herein also may optionally contain one or more molybdenum-containing compounds. An oil-soluble molybdenum compound may have the functional performance of an antiwear agent, an antioxidant, a friction modifier, or mixtures thereof.

Exemplary molybdenum-containing components may include molybdenum dithiocarbamates, molybdenum dialkyldithio phosphates, molybdenum dithiophosphinates, amine salts of molybdenum compounds, molybdenum xanthates, molybdenum thioxanthates, molybdenum sulfides, molybdenum carboxylates, molybdenum alkoxides, a trinuclearorgano-molybdenum compound, and/or mixtures thereof. Alternatively, an oil-soluble molybdenum compound may include molybdenum dithiocarbamates, molybdenum dialkyldithiophosphates, molybdenum dithiophosphinates, amine salts of molybdenum compounds, molybdenum xanthates, molybdenum thioxanthates, molybdenum sulfides, molybdenum carboxylates, molybdenum alkoxides, a trinuclear organo-molybdenum compound, and/or mixtures thereof. The molybdenum sulfides include molybdenum disulfide. The molybdenum disulfide may be in the form of a stable dispersion. In one embodiment the oil-soluble molybdenum compound may be selected from the group consisting of molybdenum dithiocarbamates, molybdenum dialkyldithiophosphates, amine salts of molybdenum compounds, and mixtures thereof. In one embodiment the oil-soluble molybdenum compound may be a molybdenum dithiocarbamate.

Suitable examples of molybdenum compounds which may be used include commercial materials sold under the trade names such as Molyvan® 822, Molyvan® A, Molyvan® 2000 and Molyvan® 855 from R. T. Vanderbilt Co., Ltd., and Sakura-Lube™ S-165, S-200, S-300, S-310G, S-525, S-600, S-700, and S-710 available from Adeka Corporation, and mixtures thereof. Suitable molybdenum components are described in U.S. Pat. No. 5,650,381; US Pat. No. RE 37,363 E1; US Pat. No. RE 38,929 E1; and US Pat. No. RE 40,595 E1, incorporated herein by reference in their entireties.

Additionally, the molybdenum compound may be an acidic molybdenum compound. Included are molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate, and other alkaline metal molybdates and other molybdenum salts, e.g., hydrogen sodium molybdate, MoOCl₄, MoO₂Br₂, Mo₂O₃Cl₆, molybdenum trioxide or similar acidic molybdenum compounds. Alternatively, the compositions can be provided with molybdenum by molybdenum/sulfur complexes of basic nitrogen compounds as described, for example, in U.S. Pat. Nos. 4,263,152; 4,285,822; 4,283,295; 4,272,387; 4,265,773; 4,261,843; 4,259,195 and 4,259,194; and WO 94/06897, incorporated herein by reference in their entireties.

Another class of suitable organo-molybdenum compounds are trinuclear molybdenum compounds, such as those of the formula Mo₃S_kL_nQ_zand mixtures thereof, wherein S represents sulfur, L represents independently selected ligands having organo groups with a sufficient number of carbon atoms to render the compound soluble or dispersible in the oil, n is from 1 to 4, k varies from 4 through 7, Q is selected from the group of neutral electron donating compounds such as water, amines, alcohols, phosphines, and ethers, and z ranges from 0 to 5 and includes non-stoichiometric values. At least 21 total carbon atoms may be present among all the ligands' organo groups, such as at least 25, at least 30, or at least 35 carbon atoms. Additional suitable molybdenum compounds are described in U.S. Pat. No. 6,723,685, herein incorporated by reference in its entirety.

The oil-soluble molybdenum compound may be present in an amount sufficient to provide about 0.5 ppm to about 2000 ppm, about 1 ppm to about 700 ppm, about 1 ppm to about 550 ppm, about 5 ppm to about 300 ppm, or about 20 ppm to about 250 ppm of molybdenum.

Transition Metal-Containing Compounds

The lubricant compositions herein also may optionally contain a transition metal-containing compound or a metalloid. The transition metals may include, but are not limited to, titanium, vanadium, copper, zinc, zirconium, molybdenum, tantalum, tungsten, and the like. Suitable metalloids include, but are not limited to, boron, silicon, antimony, tellurium, and the like.

In an embodiment, a transition metal-containing compound may function as an antiwear agent, friction modifier, antioxidant, deposit control additive, or have multiple functions. In an embodiment transition metal-containing compound may be an oil-soluble titanium compound, such as a titanium (IV) alkoxide. Among the titanium containing compounds that may be used in, or which may be used for preparation of the oils-soluble materials of, the disclosed technology are various Ti (IV) compounds such as titanium (IV) oxide; titanium (IV) sulfide; titanium (IV) nitrate; titanium (IV) alkoxides such as titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, titanium 2-ethylhexoxide; and other titanium compounds or complexes including but not limited to titanium phenates; titanium carboxylates such as titanium (IV) 2-ethyl-1-3-hexanedioate or titanium citrate or titanium oleate; and titanium (IV) (triethanolaminato)isopropoxide. Other forms of titanium encompassed within the disclosed technology include titanium phosphates such as titanium dithiophosphates (e.g., dialkyldithiophosphates) and titanium sulfonates (e.g., alkylbenzenesulfonates), or, generally, the reaction product of titanium compounds with various acid materials to form salts, such as oil-soluble salts. Titanium compounds can thus be derived from, among others, organic acids, alcohols, and glycols. Ti compounds may also exist in dimeric or oligomeric form, containing Ti—O—Ti structures. Such titanium materials are commercially available or can be readily prepared by appropriate synthesis techniques which will be apparent to the person skilled in the art. They may exist at room temperature as a solid or a liquid, depending on the particular compound. They may also be provided in a solution form in an appropriate inert solvent.

In one embodiment, the titanium can be supplied as a Ti-modified dispersant, such as a succinimide dispersant. Such materials may be prepared by forming a titanium mixed anhydride between a titanium alkoxide and a hydrocarbyl-substituted succinic anhydride, such as an alkenyl- (or alkyl) succinic anhydride. The resulting titanate-succinate intermediate may be used directly or it may be reacted with any of a number of materials, such as (a) a polyamine-based succinimide/amide dispersant having free, condensable —NH functionality; (b) the components of a polyamine-based succinimide/amide dispersant, i.e., an alkenyl- (or alkyl-) succinic anhydride and a polyamine, (c) a hydroxy-containing polyester dispersant prepared by the reaction of a substituted succinic anhydride with a polyol, aminoalcohol, polyamine, or mixtures thereof. Alternatively, the titanate-succinate intermediate may be reacted with other agents such as alcohols, aminoalcohols, ether alcohols, polyether alcohols or polyols, or fatty acids, and the product thereof either used directly to impart Ti to a lubricant, or else further reacted with the succinic dispersants as described above. As an example, tetraisopropyl titanate may be reacted with polyisobutene-substituted succinic anhydride at 140-150° C. for 5 to 6 hours to provide a titanium modified dispersant or intermediate. The resulting material may be further reacted with a succinimide dispersant from polyisobutene-substituted succinic anhydride and a polyethylene polyamine to produce a titanium-modified succinimide dispersant.

Another titanium containing compound may be a reaction product of titanium alkoxide and C₆to C₂₅carboxylic acid. The reaction product may be represented by the following formula:

embedded image

wherein p+q=4; q ranges from 1 to 3; R₁₉is an alkyl moiety with carbon atoms ranging from 1-8; R₁₆is selected from a hydrocarbyl group containing from about 6 to 25 carbon atoms; R₁₇, and R₁₈are the same or different and are selected from a hydrocarbyl group containing from about 1 to 6 carbon atoms; or by the formula:

embedded image

wherein in Formula XXIV, x ranges from 0 to 3; R₁₆is selected from a hydrocarbyl group containing from about 6 to 25 carbon atoms. R₁₇, and R₁₈are the same or different and are selected from a hydrocarbyl group containing from about 1 to 6 carbon atoms; and/or R₁₉is selected from a group consisting of either H, or C₆to C₂₅carboxylic acid moiety. Suitable carboxylic acids may include, but are not limited to caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, oleic acid, erucic acid, linoleic acid, linolenic acid, cyclohexanecarboxylic acid, phenylacetic acid, benzoic acid, neodecanoic acid, and the like.

In an embodiment the oil soluble titanium compound may be present in the lubricating oil composition in an amount to provide from 0 to 3000 ppm titanium by weight or 25 to about 1500 ppm titanium by weight or about 35 ppm to 500 ppm titanium by weight or about 50 ppm to about 300 ppm.

Viscosity Index Improvers

The lubricant compositions herein also may optionally contain one or more viscosity index improvers. Suitable viscosity index improvers may include polyolefins, olefin copolymers, ethylene/propylene copolymers, polyisobutenes, hydrogenated styrene-isoprene polymers, styrene/maleic ester copolymers, hydrogenated styrene/butadiene copolymers, hydrogenated isoprene polymers, alpha-olefin maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkyl styrenes, hydrogenated alkenyl aryl conjugated diene copolymers, or mixtures thereof. Viscosity index improvers may include star polymers and suitable examples are described in US Publication No. 20120101017A1, which is incorporated herein by reference.

The lubricating oil compositions herein also may optionally contain one or more dispersant viscosity index improvers in addition to a viscosity index improver or in lieu of a viscosity index improver. Suitable viscosity index improvers may include functionalized polyolefins, for example, ethylene-propylene copolymers that have been functionalized with the reaction product of an acylating agent (such as maleic anhydride) and an amine; polymethacrylates functionalized with an amine, or esterified maleic anhydride-styrene copolymers reacted with an amine.

The total amount of viscosity index improver and/or dispersant viscosity index improver may be about 0 wt % to about 20 wt %, about 0.1 wt % to about 15 wt %, about 0.1 wt % to about 12 wt %, or about 0.5 wt % to about 10 wt %, about 3 wt % to about 20 wt %, about 3 wt % to about 15 wt %, about 5 wt % to about 15 wt %, or about 5 wt % to about 10 wt %, of the lubricating oil composition.

In some embodiments, the viscosity index improver is a polyolefin or olefin copolymer having a number average molecular weight of about 10,000 to about 500,000, about 50,000 to about 200,000, or about 50,000 to about 150,000. In some embodiments, the viscosity index improver is a hydrogenated styrene/butadiene copolymer having a number average molecular weight of about 40,000 to about 500,000, about 50,000 to about 200,000, or about 50,000 to about 150,000. In some embodiments, the viscosity index improver is a polymethacrylate having a number average molecular weight of about 10,000 to about 500,000, about 50,000 to about 200,000, or about 50,000 to about 150,000.

Other Optional Additives

Other additives may be selected to perform one or more functions required of lubricant composition. Further, one or more of the mentioned additives may be multi-functional and provide functions in addition to or other than the function prescribed herein. The other additives may be in addition to specified additives of the present disclosure and/or may comprise one or more of metal deactivators, viscosity index improvers, detergents, ashless TBN boosters, friction modifiers, antiwear agents, corrosion inhibitors, rust inhibitors, dispersants, dispersant viscosity index improvers, extreme pressure agents, antioxidants, foam inhibitors, demulsifiers, emulsifiers, pour point depressants, seal swelling agents and mixtures thereof. Typically, fully-formulated lubricating oil will contain one or more of these additives.

Suitable metal deactivators may include derivatives of benzotriazoles (typically tolyltriazole), dimercaptothiadiazole derivatives, 1,2,4-triazoles, benzimidazoles, 2-alkyldithiobenzimidazoles, or 2-alkyldithiobenzothiazoles; foam inhibitors including copolymers of ethyl acrylate and 2-ethylhexylacrylate and optionally vinyl acetate; demulsifiers including trialkyl phosphates, polyethylene glycols, polyethylene oxides, polypropylene oxides and (ethylene oxide-propylene oxide) polymers; pour point depressants including esters of maleic anhydride-styrene, polymethacrylates, polyacrylates or polyacrylamides.

Suitable foam inhibitors include silicon-based compounds, such as siloxane.

Suitable pour point depressants may include a polymethylmethacrylates or mixtures thereof. Pour point depressants may be present in an amount sufficient to provide from about 0 wt % to about 1 wt %, about 0.01 wt % to about 0.5 wt %, or about 0.02 wt % to about 0.04 wt % based upon the final weight of the lubricating oil composition.

Suitable rust inhibitors may be a single compound or a mixture of compounds having the property of inhibiting corrosion of ferrous metal surfaces. Non-limiting examples of rust inhibitors useful herein include oil-soluble high molecular weight organic acids, such as 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, and cerotic acid, as well as oil-soluble polycarboxylic acids including dimer and trimer acids, such as those produced from tall oil fatty acids, oleic acid, and linoleic acid. Other suitable corrosion inhibitors include long-chain alpha, omega-dicarboxylic acids in the molecular weight range of about 600 to about 3000 and alkenylsuccinic acids in which the alkenyl group contains about 10 or more carbon atoms such as, tetrapropenylsuccinic acid, tetradecenylsuccinic acid, and hexadecenylsuccinic acid. Another useful type of acidic corrosion inhibitors are the half esters of alkenyl succinic acids having about 8 to about 24 carbon atoms in the alkenyl group with alcohols such as the polyglycols. The corresponding half amides of such alkenyl succinic acids are also useful. A useful rust inhibitor is a high molecular weight organic acid. In some embodiments, an engine oil is devoid of a rust inhibitor.

The rust inhibitor, if present, can be used in an amount sufficient to provide about 0 wt % to about 5 wt %, about 0.01 wt % to about 3 wt %, about 0.1 wt % to about 2 wt %, based upon the final weight of the lubricating oil composition.

The lubricant composition may also include corrosion inhibitors (it should be noted that some of the other mentioned components may also have copper corrosion inhibition properties). Suitable inhibitors of copper corrosion include ether amines, polyethoxylated compounds such as ethoxylated amines and ethoxylated alcohols, imidazolines, monoalkyl and dialkyl thiadiazole, and the like.

Thiazoles, triazoles and thiadiazoles may also be used in the lubricants. Examples include benzotriazole, tolyltriazole, octyltriazole, decyltriazole; dodecyltriazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercapto-5-hydrocarbylthio-1,3,4-thiadiazoles, and 2-mercapto-5-hydrocarbyldithio-1,3,4-thiadiazoles. In one embodiment, the lubricant composition includes a 1,3,4-thiadiazole, such as 2-hydrocarbyldithio-5-mercapto-1,3,4-dithiadiazole.

Anti-foam/Surfactant agents may also be included in a fluid according to the present invention. Various agents are known for such use. Copolymers of ethyl acrylate and hexyl ethyl acrylate, such as PC-1244, available from Solutia may be used. In other embodiments, silicone fluids, such as 4% DCF may be included. Mixtures of anti-foam agents may also be present in the lubricant composition.

Base Oil

The base oil or base oil of lubricating viscosity used in the lubricating oil compositions herein may be selected from any suitable base oil. Examples include the base oils in Groups I-V as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines. These five base oil groups are as follows:

TABLE 3

Base oil

Saturates
Viscosity

Category
Sulfur (%)

(%)
Index

Group I
>0.03
and/or
<90
80 to 120

Group II
≤0.03
and
≥90
80 to 120

Group III
≤0.03
and
≥90
≥120

Group IV
All

polyalphaolefins

(PAOs)

Group V
All others not

included in

Groups I, II, III, or

IV

Groups I, II, and III are mineral oil process stocks. Group IV base oils contain true synthetic molecular species, which are produced by polymerization of olefinically unsaturated hydrocarbons. Many Group V base oils are also true synthetic products and may include diesters, polyol esters, polyalkylene glycols, alkylated aromatics, polyphosphate esters, polyvinyl ethers, and/or polyphenyl ethers, and the like, but may also be naturally occurring oils, such as vegetable oils. It should be noted that although Group III base oils are derived from mineral oil, the rigorous processing that these fluids undergo causes their physical properties to be very similar to some true synthetics, such as PAOs. Therefore, oils derived from Group III base oils may be referred to as synthetic fluids in the industry.

The base oil used in the disclosed lubricating oil composition may be a mineral oil, animal oil, vegetable oil, synthetic oil, or mixtures thereof. Suitable oils may be derived from hydrocracking, hydrogenation, hydrofinishing, unrefined, refined, and re-refined oils, and mixtures thereof.

Unrefined oils are those derived from a natural, mineral, or synthetic source without or with little further purification treatment. Refined oils are similar to the unrefined oils except that they have been treated in one or more purification steps, which may result in the improvement of one or more properties. Examples of suitable purification techniques are solvent extraction, secondary distillation, acid or base extraction, filtration, percolation, and the like. Oils refined to the quality of an edible may or may not be useful. Edible oils may also be called white oils. In some embodiments, lubricating oil compositions are free of edible or white oils.

Re-refined oils are also known as reclaimed or reprocessed oils. These oils are obtained similarly to refined oils using the same or similar processes. Often these oils are additionally processed by techniques directed to removal of spent additives and oil breakdown products.

Mineral oils may include oils obtained by drilling or from plants and animals or any mixtures thereof. For example such oils may include, but are not limited to, castor oil, lard oil, olive oil, peanut oil, corn oil, soybean oil, and linseed oil, as well as mineral lubricating oils, such as liquid petroleum oils and solvent-treated or acid-treated mineral lubricating oils of the paraffinic, naphthenic or mixed paraffinic-naphthenic types. Such oils may be partially or fully hydrogenated, if desired. Oils derived from coal or shale may also be useful.

Useful synthetic lubricating oils may include hydrocarbon oils such as polymerized, oligomerized, or interpolymerized olefins (e.g., polybutylenes, polypropylenes, propyleneisobutylene copolymers); poly(1-hexenes), poly(1-octenes), trimers or oligomers of 1-decene, e.g., poly(1-decenes), such materials being often referred to as alpha-olefins, and mixtures thereof; alkyl-benzenes (e.g. dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes); polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls); diphenyl alkanes, alkylated diphenyl alkanes, alkylated diphenyl ethers and alkylated diphenyl sulfides and the derivatives, analogs and homologs thereof or mixtures thereof. Polyalphaolefins are typically hydrogenated materials.

Other synthetic lubricating oils include polyol esters, diesters, liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, and the diethyl ester of decane phosphonic acid), or polymeric tetrahydrofurans. Synthetic oils may be produced by Fischer-Tropsch reactions and typically may be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment oils may be prepared by a Fischer-Tropsch gas-to-liquid synthetic procedure as well as other gas-to-liquid oils.

The major amount of base oil included in a lubricating composition may be selected from the group consisting of Group I, Group II, a Group III, a Group IV, a Group V, and a combination of two or more of the foregoing, and wherein the major amount of base oil is other than base oils that arise from provision of additive components or viscosity index improvers in the composition. In another embodiment, the major amount of base oil included in a lubricating composition may be selected from the group consisting of Group II, a Group III, a Group IV, a Group V, and a combination of two or more of the foregoing, and wherein the major amount of base oil is other than base oils that arise from provision of additive components or viscosity index improvers in the composition.

The amount of the oil of lubricating viscosity in the compositions herein may be the balance remaining after subtracting from 100 wt % the sum of the amount of the performance additives. For example, the oil of lubricating viscosity that may be present in a finished fluid may be a “major amount,” such as greater than about 50 wt %, greater than about 60 wt %, greater than about 70 wt %, greater than about 80 wt %, greater than about 85 wt %, greater than about 90 wt %, or greater than 95 wt %.

In some approaches, a preferred base oil or base oil of lubricating viscosity has less than about 25 ppm sulfur, a viscosity index greater than about 120, and a kinematic viscosity at about 100° C. of about 2 to about 8 cSt. In other approaches, the base oil of lubricating viscosity has less than about 25 ppm sulfur, a viscosity index greater than 120, and a kinematic viscosity at 100° C. of about 4 cSt. The base oil may have C_P(paraffinic carbon content) of greater than 40%, greater than 45%, greater than 50%, greater than 55%, or greater than 90%. The base oil may have a C_A(aromatic carbon content) of less than 5%, less than 3%, or less than 1%. The base oil may have a C_N(naphthenic carbon content) of less than 60%, less than 55%, less than 50%, or less than 50% and greater than 30%. The base oil may have a ratio of 1 ring naphthenes to 2-6 ring naphthenes of less than 2 or less than 1.5 or less than 1.

A suitable lubricant composition may include additive components in the ranges listed in the following Table 4.

TABLE 4

Wt %
Wt %

(Suitable
(Preferred

Component
Embodiments)
Embodiments)

Olefin Copolymer Dispersant “B”, “C”,
0.1-15.0
1.0-8.0

“E”, or “F” described below

Antioxidant(s)
0.1-5.0
0.01-4.0

Detergent(s)
0.0-15.0
1.0-8.0

Ashless TBN booster(s)
0.0-1.0
0.01-0.5

Corrosion inhibitor(s)
0.0-5.0
0.1-3.0

Metal dihydrocarbyl dithiophosphate(s)
0.0-15.0
0.1-5.0

Ash-free phosphorus compound(s)
0.0-15.0
0.1-5.0

Antifoaming agent(s)
0.0-1.0
0.001-0.5

Other Antiwear agent(s)
0.0-1.0
0.0-0.8

Pour point depressant(s)
0.0-1.0
0.01-0.5

Viscosity index improver(s)
0.0-20.0
0.1-10.0

Other Dispersants
0.0-10.0
1.0-6.0

Dispersant viscosity index improver(s)
0.0-10.0
0.0-5.0

Friction modifier(s)
0.0-10.0
0.01-4.0

Extreme Pressure Agent (S wt %)
0.0-1.05
.035-.35

Base oil(s)
Balance
Balance

Total
100
100

The percentages of each component above represent the weight percent of each component, based upon the weight of the total final lubricating oil composition. The balance of the lubricating oil composition consists of one or more base oils. Additives used in formulating the compositions described herein may be blended into the base oil individually or in various sub-combinations. However, it may be suitable to blend all of the components concurrently using an additive concentrate (i.e., additives plus a diluent, such as a hydrocarbon solvent).

Fully formulated lubricants conventionally contain an additive package, often referred to as a dispersant/inhibitor package or DI package, that will supply the characteristics that are required in the formulations. Suitable DI packages are described for example in U.S. Pat. Nos. 5,204,012 and 6,034,040 for example. Among the types of additives included in the additive package may be dispersants, seal swell agents, antioxidants, foam inhibitors, lubricity agents, rust inhibitors, corrosion inhibitors, demulsifiers, viscosity index improvers, and the like. Several of these components are well known to those skilled in the art and are generally used in conventional amounts with the additives and compositions described herein.

Tables 5A-5J provide examples of fully formulated lubricant compositions containing the olefin copolymer dispersants described herein in combination with various types of additives.

TABLE 5A

Passenger Car Formulation¹

Component

Olefin copolymer dispersant “B” described
4
wt %

below

Phenolic, aminic, and sulfur containing
1.5
wt %

antioxidants

Calcium and magnesium phenates, calcium
<3500
ppm metal

and magnesium sulfonates, calcium and

magnesium salicylate detergents, calcium

and magnesium salixrate detergents,

calcium and magnesium saligenin

detergents, and borated detergent²

Zinc dihydrocarbyl dithiophosphate(s)
<1200
ppm phosphorus

Silicon based antifoaming agent(s)
0.15
wt %

Linear and star olefin copolymer and
<9
wt %

polymethacrylate viscosity index improver

Tartrate derivatives: tartrimide and
<1.5
wt %

tartramide friction modifiers

Molybdenum succinimide complex friction
<4
wt %

modifier

Bi-nuclear and tri-nuclear molybdenum
<0.4
wt %

compounds

Borated glycerol monooleate
<0.25
wt %

Polymeric friction modifier³
0.25
wt %

Base Oils: Group II, III, and IV mixture
Balance

¹The formulation has a sulfated ash content of less than or equal to 1.2 mass % as determined by ASTM D874

²The detergents include a 250 TBN calcium phenate having 9.25% Ca, 300 TBN calcium sulfonate having about 11.6% Ca, 400 TBN magnesium sulfonate having about 9.1% Mg, 27 TBN calcium sulfonate having about 2.6% Ca, 340 TBN magnesium salicylate having about 7.4% Mg, and 165 TBN calcium salicylate having about 6.1% Ca.

³The polymeric friction modifier is a reaction product of: (i) a functionalized polyolefin, such as a polyisobutylene functionalized with a diacid or anhydride functional group; (ii) polyethylene glycol or polypropylene glycol or a mixed poly(ethylene-propylene) glycol; and (iii) a monocarboxylic acid, such as oleic acid.

TABLE 5B

Manual Transmission Formulation

Component

Olefin copolymer dispersant “C” described herein
1.12 wt %

Aromatic amine antioxidant(s)
0.5 wt %

690 TBN (on an oil free basis) calcium sulfonate detergent
2.42 wt %

having 0.67% Ca

590 TBN (on an oil free basis) magnesium sulfonate detergent
2.38 wt %

having 0.33% Mg

Dibutyl hydrogen phosphonate
0.2 wt %

Bis(hydrocarbyldithio)thiadiazole
0.2 wt %

Polyalphaolefin having a kV100 of 100 cSt
8%

Base Oil: polyalphaolefin having a kV100 of 4 cSt
Balance

100%

TABLE 5C

TO-4 Compliant Off-Road Formulation

Component

Olefin copolymer dispersant “E” described herein
1.6 wt %

Olefin copolymer dispersant “F” described herein
0.4 wt %

300 TBN calcium detergent (42% in oil), having
0.61 wt %

approximately 11.6 wt % Ca

Dibutyl hydrogen phosphonate
0.42 wt %

mixture of hydrocarbyl esters of sulfur-containing
0.63 wt %

phosphoric acid alkylamine salts

Isostearic acid-tetraethylene pentamine condensate
0.35 wt %

Block copolymer (50% in oil) of lauryl methacrylate and
0.2 wt %

C₁₆-C₁₈alkyl methacrlate-b-dimethlaminoethyl

methacrylate (Mn 50,000)

N-tallow-N,N-diethanolamine, commercially available as
0.14 wt %

Ethomeen ® T/12

Zinc oleate
0.32 wt %

Polymethacrylate viscosity modifier (Mn 40,000 and 28%
4.8 wt %

in oil)

Polymethacrylate RAFT made star polymer viscosity
1.2 wt %

modifier (Mn 50,000 28% in oil)

Succinic ester/amide corrosion inhibitor (49% oil)
0.5 wt %

Succinc acid condensate with diethanolamine (33% oil)
0.20 wt %

Polyisobutylene succinic anhydride
0.07 wt %

Aromatic amine antioxidant
0.59 wt %

Bis(hydrocarbyldithio)thiadiazole
0.2 w %

Antifoam
0.016 wt %

Base Oil: Group III having a kV100 of 4 cSt
Balance

100%

TABLE 5D

Heavy Duty Diesel Formulation⁴

Component

Olefin copolymer dispersant “C” described herein
5.2
wt %

Polyisobutylene dispersant capped with maleic
3
wt %

anhydride and/or naphthalic anhydride

Methylene bis di-n-butyl dithiocarbamate
0.7
wt %

Molybdenum succinimide complex
90
ppm Mo

Borated polyisobutylene dispersant
3
wt %

160 TBN Borated calcium sulfonate
3000
ppm Ca

Diphenylamine antioxidant
1
wt %

Hindered phenol antioxidant
1
wt %

Pour point depressant
0.5
wt %

Dispersant viscosity index improver
4.5
wt %

PIBSA dispersant capped with ethylene carbonate
4.0
wt %

Silicon antifoam
10
ppm Si

Base Oil: Group II and Group III mixture
Balance

100%

⁴The heavy duty diesel formulation may be contaminated with at least about 0.3 wt % biodiesel fuel.

TABLE 5E

Automatic Transmission Formulation

Component

Olefin copolymer dispersant “E” described herein
5.0 wt %

Olefin copolymer dispersant “B” described herein having
0.6 wt %

an olefin copolymer with C₁₂-C₃₀chain, functioning

as a friction modifier

Olefin copolymer dispersant “C” described herein having
0.6 wt %

an olefin copolymer with C₂₀-C₃₀chain, functioning

as a friction modifier

Additional phosphorylated and borated dispersant
6.0 wt %

Nonylated diphenyl amine
0.25 wt %

Sulfurized fat
0.4 wt %

2-Oleyl-1-Hydroxyethylimidazoline, commercially
0.02 wt %

available as Varine O.

Monoalkyl-succinimide friction modifier, having C₂₀-C₃₀
0.6 wt %

alkyl chains

N-tallow-N,N-diethanolamine, commercially available as
0.5 wt %

Ethomeen ® T-12

Bisalkyl-succinimide friction modifier, having C₁₂-C₃₀
0.6 wt %

alkyl chains, made using a polyalkylene polyamine,

such as TETA,

TEPA or polyamine bottoms.

PMA viscosity modifier
3.0 wt %

Process Oil
10.0 wt %

Base Oil: Group III
Balance

100%

TABLE 5F

Automotive Gear Formulation 1

Component

Olefm copolymer dispersant “F” described herein
1.07 wt %

Sulfurized isobutylene and dialkyl polysulfides
3.46 wt %

Pour point depressant
1.82 wt %

Bis(hydrocarbyldithio)thiadiazole
0.13 wt %

Aromatic amine antioxidant
0.25 wt %

Silicon antifoam
0.05 wt %

Dimer acid
0.01 wt %

dithiophosphate ester antiwear component⁵
1.2 wt %

Base Oil: Group I, II, or mixtures thereof
Balance

100%

⁵The dithiophosphate ester antiwear component is made by the following series of reactions: O,O-bis(4-methylpentan-2-yl) S-hydrogen phosphorodithioate is reacted with propylene oxide to form a first reaction product which is further reacted with O,O-di-isopropyl dithiophosphoric acid to form a second reaction product. The second reaction product is reacted with additional propylene oxide and O,O-di-isopropyl dithiophosphoric acid to form a third reaction product. The third reaction product is then reacted with ethyl acrylate. Specific details of this series of reactions are found in Example 1 of U.S. Pat. No. 9,481,696.

TABLE 5G

Automotive Gear Formulation 2

Component

Olefin copolymer dispersant “B” described herein
0.5 wt %

Sulfur-free hydrocarbyl phosphoric acid salt
0.035 wt %

Dithiophosphate ester amine salt⁶
0.3 wt %

Organic polysulfide
3.5 wt %

Tolytriazole
0.2 wt %

Polyalphaolefin having a kV100 of 100 cSt
0.04%

Base Oils: Group II, III, and PAO mixture
Balance

100%

⁶Dithiophosphate ester amine salt is a reaction product made by reacting an O,O′-di-4-methyl-2-pentanylphosphorodithioic acid and ethylene oxide and further reacted with phosphorus pentoxide and then neutralized with aliphatic primary amines, e.g., Primene ® 81-R.

TABLE 5H

Hydraulic Formulation

Component

Olefin copolymer dispersant “C” described herein
0.06 wt %

150 TBN calcium hydroxybenzoate detergent (5.35% Ca)
0.225 wt %

Zinc dialkyl dithiophosphate
0.31 wt %

Hindered phenol antioxidant
0.15 wt %

Fatty ester friction modifier
.044 wt %

Arylpolyol demulsifier
0.013%

Antifoam
0.008 wt %

Polymethacrylate viscosity index improver
8 wt %

Base Oils: Group I, II, or mixtures thereof
Balance

100%

TABLE 5I

Industrial Gear Formulation

Component

Olefin copolymer dispersant “E” described herein
0.25 wt %

aminobisphosphonate antiwear agent⁷
0.24 wt %

sulfurized olefin extreme pressure agent
0.71 wt %

heterocyclic corrosion inhibitor
0.06 wt %

fatty acid corrosion inhibitor
0.03 wt %

Phenolic antioxidant
0.15 wt %

EO/PO copolymer demulsifier
0.003 wt %

acrylate pour point depressant
0.25 wt %

Base Oils: Group I mineral oil
Balance

100%

⁷Aminobisphosphonate antiwear agent is tetrabutyl(((2-hydroxyethyl)azanediyl)bis(methylene))bis(phosphonate) as described in detail in Compound 1 of U.S. Patent Publication 2018/0099985.

TABLE 5J

Slideway Formulation

Component

Olefin copolymer dispersant “F” described herein
1.0-5.0
wt %

Metal detergent
0.2-2.0
wt %

Corrosion inhibitor
0-2.0
wt %

Antiwear agent
0.1-0.6
wt %

Metal free amine containing friction modifier
0.1-0.6
wt %

Supplemental friction modifiers
0.1-1.5
wt %

Antifoam agent
0.001-0.15
wt %

Acrylate pour point depressant
0.01-1.5
wt %

Viscosity modifier
0.25-10.0
wt %

Base Oils: Group I mineral oil
Balance

100%

In further embodiments, the invention relates to a method for lubricating an engine by lubricating an engine with a lubricant composition of any of the forgoing embodiments. In yet a further embodiment, the invention relates to the use of a lubricant composition according to any of the forgoing embodiments to lubricate an engine and/or use of lubricant composition to achieve reduced friction coefficients and/or improved low temperature viscosity characteristics as demonstrated in Tables 7-14.

Lubricants, combinations of components, or individual components of the present description may be suitable for use as a lubricant in various types of internal combustion engines. Suitable engine types may include, but are not limited to, heavy duty diesel, passenger car, light duty diesel, medium speed diesel, or marine engines. An internal combustion engine may be a diesel fueled engine, a gasoline fueled engine, a natural gas fueled engine, a bio-fueled engine, a mixed diesel/biofuel fueled engine, a mixed gasoline/biofuel fueled engine, an alcohol fueled engine, a mixed gasoline/alcohol fueled engine, a compressed natural gas (CNG) fueled engine, or mixtures thereof. A diesel engine may be a compression ignited engine. A gasoline engine may be a spark-ignited engine. An internal combustion engine may also be used in combination with an electrical or battery source of power. An engine so configured is commonly known as a hybrid engine. The internal combustion engine may be a 2-stroke, 4-stroke, or rotary engine. Suitable internal combustion engines include marine diesel engines (such as inland marine), aviation piston engines, low-load diesel engines, and motorcycle, automobile, locomotive, and truck engines.

The lubricating oil composition for an internal combustion engine may be suitable for any engine lubricant irrespective of the sulfur, phosphorus, or sulfated ash (ASTM D-874) content. In some approaches, the sulfur content of the engine oil lubricants herein may be about 1 wt % or less, or about 0.8 wt % or less, or about 0.5 wt % or less, or about 0.3 wt % or less, or about 0.2 wt % or less. In one embodiment the sulfur content may be in the range of about 0.001 wt % to about 0.5 wt %, or about 0.01 wt % to about 0.3 wt %. The phosphorus content of the engine oil lubricants herein may be about 0.2 wt % or less, or about 0.1 wt % or less, or about 0.085 wt % or less, or about 0.08 wt % or less, or even about 0.06 wt % or less, about 0.055 wt % or less, or about 0.05 wt % or less. In one embodiment the phosphorus content may be about 50 ppm to about 1000 ppm, or about 325 ppm to about 850 ppm, or up to 600 ppm. The total sulfated ash content of the engine oil lubricants herein may be about 2 wt % or less, or about 1.5 wt % or less, or about 1.1 wt % or less, or about 1 wt % or less, or about 0.8 wt % or less, or about 0.5 wt % or less. In one embodiment the sulfated ash content may be about 0.05 wt % to about 0.9 wt %, or about 0.1 wt % or about 0.2 wt % to about 0.45 wt %.

Further, lubricants of the present description may be suitable to meet one or more industry specification requirements such as ILSAC GF-3, GF-4, GF-5, GF-6, CK-4, FA-4, CJ-4, CI-4 Plus, CI-4, ACEA A1/B1, A2/B2, A3/B3, A3/B4, A5/B5, C1, C2, C3, C4, C5, E4/E6/E7/E9, Euro 5/6, JASO DL-1, Low SAPS, Mid SAPS, or original equipment manufacturer specifications such as Dexos™ 1, Dexos™ 2, MB-Approval 229.51/229.31, VW 502.00, 503.00/503.01, 504.00, 505.00, 506.00/506.01, 507.00, 508.00, 509.00, BMW Longlife-04, Porsche C30, Peugeot Citroen Automobiles B71 2290, B71 2296, B71 2297, B71 2300, B71 2302, B71 2312, B71 2007, B71 2008, Ford WSS-M2C153-H, WSS-M2C930-A, WSS-M2C945-A, WSS-M2C913A, WSS-M2C913-B, WSS-M2C913-C, GM 6094-M, Chrysler MS-6395, or any past or future passenger car motor oil or heavy duty diesel oil specifications not mentioned herein. In some embodiments for passenger car motor oil applications, the amount of phosphorus in the finished fluid is 1000 ppm or less or 900 ppm or less or 800 ppm or less or 600 ppm or less. In some embodiments for heavy duty diesel applications, the amount of phosphorus in the finished fluid is 1200 ppm or less or 1000 ppm or less or 900 ppm or less or 800 ppm or less.

In certain applications, the lubricants of the present disclosure may also be suitable for automatic transmission fluids, continuously variable transmission fluids, manual transmission fluids, gear oils, other fluids related to power train components, off-road fluids, power steering fluids, fluids used in wind turbines, compressors, hydraulic fluids, slideway fluids, and other industrial fluids. In certain applications, these lubricating applications may include lubrication of gearboxes, power take-off and clutch(es), rear axles, reduction gears, wet brakes, and hydraulic accessories.

EXAMPLES

The following examples are illustrative, but not limiting, of the methods and compositions of the present disclosure. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in the field, and which are obvious to those skilled in the art, are within the spirit and scope of the disclosure. Unless otherwise noted by the context of the disclosure, all percentages, ratios, amounts, and parts are by weight. When used in the tables below, and throughout the text, elemental concentrations, such as ppm phosphorus or ppm nitrogen, are measured using standard inductively coupled plasma (ICP) spectroscopy techniques.

The following base oil and components were used to test the inventive and comparative examples shown in the tables below.

Base Oil

A: The Base Oil was a Group III base oil with a kinematic viscosity at 100° C. of about 4 cSt, having less than 25 ppm sulfur, a viscosity index than 120, C_Pof greater than 55%, C_Aof less than 1%, and C_Nof greater than 30%, and a ratio of 1 ring naphthenes to 2-6 ring naphthenes of less than 1.5.

Olefin Copolymer Dispersants

B: Dispersant prepared by reacting ethylene-propylene copolymer with maleic anhydride which was then further reacted with polyethylene polyamine having 5 or an average of 5 nitrogen atoms to form a succinimide product. The ethylene-propylene copolymer had about 49 mol % ethylene (mole fraction of ethylene incorporated into the copolymer (x_C2) was 0.49), 51 mol % propylene, and a Mn of 870 g/mol as determined by ¹H-NMR and Mn of 1603 g/mol as determined by GPC. The polydispersity index (PDI) of the copolymer was 1.76. The charge molar ratio of maleic anhydride to ethylene propylene copolymer was 1.3:1. The alkenyl succinic anhydride to polyamine charge molar ratio was 1.8:1. The dispersant contained about 2.9 wt % nitrogen and has a TBN of about 63.9. The average ethylene run length (n_{C2, Experimental}) was 1.83. The copolymer of this dispersant satisfies the relationship:

n
_{C2,Experimental}
<n
_{C2,Statistical}.

C: Dispersant prepared by reacting ethylene-propylene copolymer with maleic anhydride which was then further reacted with polyethylene polyamine having 5 or an average of 5 nitrogen atoms to form a succinimide product. The ethylene-propylene copolymer had 51 mol % ethylene (mole fraction of ethylene incorporated into the copolymer (x_C2) was 0.51), 49 mol % propylene, and a Mn of 1411 g/mol as determined by ¹H-NMR and Mn of 2700 g/mol as determined by GPC. The PDI of the copolymer was 2.05. The charge molar ratio of maleic anhydride to ethylene propylene copolymer was 1.5:1. The alkenyl succinic anhydride to polyamine charge molar ratio was 1.8:1. The dispersant contained about 1.8 wt % nitrogen and a TBN of about 35.6. The average ethylene run length (n_{C2, Experimental}) was 1.97. The copolymer of this dispersant satisfies the relationship: n_{C2,Experimental}<n_{C2,Statistical}.

D: Dispersant prepared by reacting ethylene-propylene copolymer with maleic anhydride which was then further reacted with polyethylene polyamine having 5 or an average of 5 nitrogen atoms to form a succinimide product. The ethylene-propylene copolymer had 68 mol % ethylene (mole fraction of ethylene incorporated into the copolymer (x_C2) was 0.68), 42 mol % propylene, and a Mn of 1185 g/mol as determined by ¹H-NMR and Mn of 2550 g/mol as determined by GPC. The PDI of the copolymer was 2.02. The charge molar ratio of maleic anhydride to ethylene propylene copolymer was 1.3:1. The alkenyl succinic anhydride to polyamine charge molar ratio was 1.8:1. The dispersant contained about 2.0 wt % nitrogen and a TBN of about 42.5. The average ethylene run length (n_{C2, Experimental}) was 2.69, and thus, is outside the average ethylene run length of the present invention.

E: Dispersant prepared by reacting ethylene-propylene copolymer with maleic anhydride which was then further reacted with polyethylene polyamine having 5 or an average of 5 nitrogen atoms to form a succinimide product. The ethylene-propylene copolymer had 53 mol % ethylene (mole fraction of ethylene incorporated into the copolymer (x_C2) was 0.53), 47 mol % propylene, and a Mn of 747 g/mol as determined by ¹H-NMR and Mn of 1390 g/mol as determined by GPC. The PDI of the copolymer was 2.0. The charge molar ratio of maleic anhydride to ethylene propylene copolymer was 1.3:1. The alkenyl succinic anhydride to polyamine charge molar ratio was 1.8:1. The dispersant contained about 2.4 wt % nitrogen and a TBN of about 52.4. The average ethylene run length (n_{C2, Experimental}) was 2.0. The copolymer of this dispersant satisfies the relationship: n_{C2,Experimental}<n_{C2,Statistical}.

F: Dispersant prepared by reacting ethylene-propylene copolymer with maleic anhydride which was then further reacted with polyethylene polyamine having 5 or an average of 5 nitrogen atoms to form a succinimide product. The succinimide product was post treated with boric acid and maleic anhydride. The ethylene-propylene copolymer had 49 mol % ethylene (mole fraction of ethylene incorporated into the copolymer (x_C2) was 0.49), 51 mol % propylene, and a Mn of 870 g/mol as determined by ¹H-NMR and Mn of 1603 g/mol as determined by GPC. The PDI of the copolymer was 1.78. The charge molar ratio of maleic anhydride to ethylene propylene copolymer was 1.3:1. The alkenyl succinic anhydride to polyamine charge molar ratio was 1.8:1. Boric acid was added to the succinimide product in an amount to provide 0.8 wt % boron to the succinimide product. Maleic anhydride was charged at 0.3 molar ratio to the succinimide product. The dispersant contained about 1.9 wt % nitrogen and a TBN of about 35.5. The average ethylene run length (n_C2) was 1.83. The copolymer of this dispersant satisfies the relationship: n_{C2,Experimental}<n_{C2,Statistical}.

Polyisobutylene Dispersants

G: Dispersant prepared by reacting polyisobutylene with maleic anhydride which was then further reacted with polyethylene polyamine having 5 or an average of 5 nitrogen atoms to form a succinimide product. The polyisobutylene had a Mn of approximately 950 g/mol as determined by ¹H-NMR and Mn of 1191 g/mol as determined by GPC. The PDI of the polymer was 1.78. The charge molar ratio of maleic anhydride to polyisobutylene was 1.1:1. The alkenyl succinic anhydride to polyamine charge molar ratio was 2.2:1. The dispersant contained about 2.1 wt % nitrogen and TBN of about 42.

H: Dispersant prepared by reacting polyisobutylene with maleic anhydride which was then further reacted with polyethylene polyamine having 5 or an average of 5 nitrogen atoms to form a succinimide product. The polyisobutylene had a Mn of approximately 1300 g/mol as determined by ¹H-NMR and Mn of 1614 g/mol as determined by GPC. The PDI of the polymer was 1.69. The charge molar ratio of maleic anhydride to polyisobutylene was 1.5:1. The alkenyl succinic anhydride to polyamine charge molar ratio was 1.8:1. The dispersant contained about 1.8 wt % nitrogen and TBN of about 42.

ZDDPs

I: zinc dialkyldithiophosphate wherein 100% of the alkyl groups were C₆and derived from a secondary alcohol (4-methyl-2-pentanol). The ZDDP contained about 7.1 wt % phosphorus, about 14.8 wt % sulfur, and about 7.8 wt % zinc.

J: zinc dialkyldithiophosphate and included mixed alkyl groups with about 50% of the alkyl groups being C6 and derived from a secondary alcohol (4-methyl-2-pentanol), and about 50% of the alkyl groups being C₃and derived from a secondary alcohol (isopropanol). The ZDDP contained about 8.2 wt % phosphorus, about 17.1 wt % sulfur, and about 9.0 wt % zinc.

K: zinc dialkyldithiophosphate and included mixed alkyl groups with about 40% of the alkyl groups being C₃and derived from a secondary alcohol (isopropanol), about 40% of the alkyl groups being C₄and derived from a primary alcohol (isobutanol), and about 20% of the alkyl groups being C₈and derived from a primary alcohol (2-ethylhexanol). The ZDDP contained about 8.35 wt % phosphorus, 17.8 wt % sulfur, and about 9.2 wt % zinc.

L: zinc dialkyldithiophosphate and wherein 100% of the alkyl groups were C₈and derived from a primary alcohol (2-ethylhexanol). The ZDDP contained about 6.1 wt % phosphorus, about 12.7 wt % sulfur, and about 6.75 wt % zinc.

Ashless Antiwear Agents

M: dialkyl dithiophosphate ester known as 3-((diisobutoxyphosphorothioyl)thio)-2-methylpropanoic acid having about 9.0 wt % phosphorus and about 10.0 wt % sulfur.

N: a mixture of amyl acid phosphate and diamyl acid phosphate having about 15.0 w % phosphorus.

O: dibutyl hydrogen phosphonate having about 15.5 wt % phosphorus.

P: dimethyl octadecyl phosphonate having about 8.3 wt % phosphorus.

Detergents

Q: 300 TBN Ca sulfonate having about 11.9% Ca and about 25% soap content.

R: 250 TBN Ca phenate having about 9.25% Ca and about 33% soap content.

S: 400 TBN Mg sulfonate having about 9.1% Mg (commercially available as Infineum C9340).

T: 165 TBN Ca salicylate having about 6.1% Ca (commercially available as OSCA463).

U: 28 TBN Ca sulfonate having about 2.6% Ca and about 40% soap content.

Extreme Pressure Agents

V: sulfurized olefin, derived from C₁₅-C₁₈olefin, and having about 12.7% sulfur.

W: 2,5-dimercapto-1,3,4-thiadiazole having about 35% sulfur.

X: sulfurized isobutylene, having about 46% sulfur.

Y: mixture of polysulfides having a majority of S₃and S₄sulfides, having about 48% sulfur.

Friction Modifiers

Z: mixture of glycerol monooleate, glycerol dioleate, glycerol trioleate and oleic acid containing about 60 wt % of glycerol monooleate, about 35% glycerol dioleate, and about 5% glycerol trioleate and oleic acid.

AA: an imidazoline derivative chemically known as 2-(2-heptadec-1-enyl-4,5-dihydroimidazol-1-yl)ethanol, having about 8.25% nitrogen (commercially available as Unamine® O).

BB: an ethoxylated amine chemically known as N,N-bis(2-hydroxyethyl)-N-tallow amine, having about 4% nitrogen (commercially available as Ethomeen® T/12).

CC: oleylamine, having about 5.15% nitrogen (commercially available as Armeen® OL).

DD: oleyl sarcosine, having about 3.9% nitrogen (commercially available as Sarkosyl® O).

EE: the reaction product of oleyl amine and excess diethyl L-tartrate, reacted in the presence of 0.01 equivalents of boric acid catalyst at 140 C for 1 hour under vacuum. The temperature was then raised to 170 C to distill off excess diethyl L-tartrate, leaving oleylamine tartrimide as the primary reaction product.

FF: cerium oxide nanoparticles made by reacting a cerium acetate, oleic acid, and oleyl amine. The nanoparticles were obtained following the procedure described in Example 1 of U.S. Pat. No. 8,741,821 and had a particle size less than 10 nanometers.

GG: reaction product of titanium alkoxide and neodecanoic acid, having about 3.3% titanium.

HH: molybdenum dithiocarbamate, having about 10.1% Mo (commercially available as Molyvan® 3000).

Complex Viscosity

The dispersants comprising olefin copolymers of the parameters specified herein have improved low temperature properties as compared to other dispersants with other olefin copolymers. To demonstrate these improved low temperature properties, the complex viscosity of several samples were tested.

An Anton-Paar model MCR302 Rheometer was used to measure the complex viscosity of the samples at −30° C. The samples were cooled at approximately 1° C. per minute from room temperature down to −30° C. All measurements were made using parallel-plate geometry. To eliminate condensation on the sample and plates, the system was housed in a thermally controlled hood with a nitrogen purge. The rheometer was operated in the oscillatory mode with angular frequency of 2 radians per second and angular displacement of 1 milli-radians. All data were collected in the linear viscoelastic region. The tested dispersants, B, C, and D, were added to the base oil at concentrations to deliver various amounts of nitrogen to the fluid.

TABLE 7

Average

ethylene run

Complex

length
Dispersant
Viscosity

Run
Samples
(n_{C2,Experimental})
Treat Rate (wt %)
(Pa-s)

1
A
—
—
0.54

2
A + B
1.83
2.48
0.92

(treated at an amount to

deliver 719 ppm N)

3
A + B
1.83
4.96
1.05

(treated at an amount to

deliver 1438 ppm N)

4
A + C
1.97
4.0
1.76

(treated at an amount to

deliver 720 ppm N)

5
A + D
2.69
3.2
3.43

(treated at an amount to

deliver 640 ppm N)

6
A + D
2.69
3.6
2.51

(treated at an amount to

deliver 720 ppm N)

7
A + D
2.69
7.19
5.90

(treated at an amount to

deliver 1438 ppm N)

As shown in Table 7, the addition of the olefin copolymer dispersants having the characteristics described herein to a base oil imparts a relatively small complex viscosity to the fluid as compared to the addition of dispersants having olefin copolymers outside the specified conditions set forth herein. Note that Runs 2-4, containing the dispersants having the olefin copolymers described herein, result in minimal low temperature complex viscosity change as compared to the lubricant of Runs 5-7, containing a dispersant having another olefin copolymer (e.g., Dispersant “D” has a copolymer with an average ethylene run length greater than 2.6). This data demonstrates that the lubricating compositions comprising the dispersant described herein have improved low temperature properties.

Friction Coefficient

Tables 8-14 below provide the friction coefficients for various lubricating compositions. The friction coefficient was measured at 130° C. using a High Frequency Reciprocating Rig (HFRR) using test conditions as generally described in SAE paper 982503. This test determined the samples' friction coefficients using an SAE 52100 metal ball and an SAE 52100 metal disk. The ball was oscillated across the disk at a frequency of 20 Hz over a 1 mm path, with an applied load of 4.0 N. Each sample was tested in the HFRR for 10 minutes and the data over the last 2 minutes was averaged to produce the friction coefficients. The friction coefficients measured in this test are indicative of the lubricant's ability to reduce boundary layer friction in real-world applications. A lower friction coefficient is indicative of lower boundary friction.

Friction Coefficients for Base Oil and Base Oil plus ZDDP

Table 8 provides the friction coefficients for base oil alone and base oil plus a single ZDDP. The friction coefficient of the base oil was used to establish a base-line friction coefficient. The ZDDPs were treated at an amount to deliver 800 ppm to the fluid.

TABLE 8

Samples
Friction Coefficient

Comp 1
A
0.214

Comp 2
A + I
0.160

Comp 3
A + J
0.198

Comp 4
A + K
0.129

Comp 5
A + L
0.120

Friction Coefficients for Base Oil Comprising Dispersants and ZDDPs

Table 9 provides the friction coefficients for lubricating compositions containing a ZDDP and either a polyisobutylene dispersant or an olefin copolymer dispersant described herein. Unless otherwise indicated in Table 9, each ZDDP was treated at an amount to deliver 800 ppm phosphorus to the fluid and each dispersant was treated at an amount to deliver 1.35 TBN to the fluid.

TABLE 9

Samples
Friction Coefficient

Comp 6
A + G + I
0.154

Inv 1
A + B + I
0.123

Inv 2
A + E + I
0.137

Inv 3
A + F + I
0.128

Comp 7
A + H + I
0.158

Inv 4
A + C + I
0.122

Inv 5
A + C + I
.134

(C treated at an amount

to deliver .36 TBN)

(I treated at an amount to

deliver 3550 ppm P)

Inv 6
A + C + I
.127

(C treated at an amount

to deliver .36 TBN)

(I treated at an amount to

deliver 71 ppm P)

Inv 7
A + C + I
.139

(C treated at an amount

to deliver 2.14 TBN)

(I treated at an amount to

deliver 71 ppm P)

Comp 8
A + G + J
0.157

Inv 8
A + B + J
0.122

Comp 9
A + G + K
0.157

Inv 9
A + B + K
0.123

Comp 10
A + G + L
0.158

Inv 10
A + B + L
0.125

As shown in Table 9, the lubricant compositions containing base oil and an olefin copolymer dispersant described herein in combination with ZDDP exhibit lower friction coefficients when compared to fluids containing similar molecular weight polyisobutylene dispersants in combination with the ZDDP. This inventive effect is maintained in lubricant compositions containing independently relatively high and low treat rates of the olefin copolymer dispersant herein and relatively high and low treat rates of ZDDP. For example, when compared to Comparative sample 7, Inventive samples 2-5 demonstrate that the friction coefficient is lowered even when the treat rates of the olefin copolymer dispersant and the ZDDP are significantly increased or decreased.

The inventive effect is even further pronounced when the olefin copolymer dispersant is combined with a ZDDP having greater than 40% of the alkyl groups thereon being derived from secondary alcohols. Table 8 illustrates that in the presence of only base oil, ZDDPs having greater than 40% of the alkyl groups being derived from secondary alcohols (e.g., ZDDPs “I” and “J”) do not lower the friction coefficient as effectively as the ZDDPs having 40% or less of the alkyl groups being derived from secondary alcohols (e.g., ZDDPs “K” and “L”). For example, the friction coefficient of the base oil alone was 0.214 (see Comparative sample 1), and only slightly improved to 0.198 (see Comparative sample 3) when blended with ZDDP “J” (having 100% of the alkyl groups being derived from secondary alcohols), whereas the friction coefficient significantly improved to 0.120 (see Comparative sample 5) when base oil was blended with ZDDP “L” (having 100% of the alkyl groups being derived from primary alcohols). However, when ZDDPs exhibiting less frictional impact (those having greater than 40% of the alkyl groups being derived from secondary alcohols, ZDDPs “I” and “J”) are blended with the olefin copolymer dispersant, the combination of additives exhibit a synergistic improvement in the friction coefficient. This is illustrated in Inventive samples 4-8. The olefin copolymer dispersants herein tend to transform fluids containing ZDDPs having higher friction coefficients into fluids with improved, i.e., lower, frictional properties.

Friction Coefficients for Base Oil Comprising Dispersants and Ashless Antiwear Compounds

Table 10 provides the friction coefficients for lubricating compositions containing an ashless antiwear compound and either a polyisobutylene dispersant or an olefin copolymer dispersant. Each ashless antiwear compound was treated at an amount to deliver the noted level of phosphorus in Table 10. Unless otherwise noted, each dispersant was treated at an amount to deliver 720 ppm nitrogen to the fluid.

TABLE 10

Ashless Antiwear

treated to deliver the

noted amount of

Phosphorus
Friction

Samples
(ppm P)
Coefficient

Comp 11
A + H + M
900
0.159

Inv 11
A + C + M
900
0.136

Inv 12
A + C + M
180
0.127

Inv 13
A + C + M
1800
0.135

Comp 12
A + H + N
1500
0.144

Inv 14
A + C + N
1500
0.106

Inv 15
A + C + N
150
0.133

(C treated at an amount

to deliver 1440 ppm N)

Inv 16
A + C + N
4500
0.107

(C treated at an amount

to deliver 180 ppm N)

Comp 13
A + H + O
1550
0.166

Inv 17
A + C + O
1550
0.118

Inv 18
A + C + O
310
.138

Inv 19
A + C + O
3100
.088

Comp 14
A + H + P
830
0.161

Inv 20
A + C + P
830
0.131

Inv 21
A + C + P
83
0.134

(C treated at an amount

to deliver 1440 ppm N)

Inv 22
A + C + P
2490
0.097

(C treated at an amount

to deliver 180 ppm N)

As shown in Table 10, the lubricant compositions containing base oil and olefin copolymer dispersants in combination with ashless antiwear compounds exhibit lower friction coefficients when compared to fluids containing similar Mn polyisobutylene dispersants in combination with the ashless antiwear compounds. This inventive effect is maintained in lubricant compositions containing independently relatively high and low treat rates of the olefin copolymer dispersants and relatively high and low treat rates of ashless antiwear compounds. For example, when compared to Comparative sample 12, Inventive samples 14-16 demonstrate that friction coefficients are lowered even when the treat rates of the olefin copolymer dispersant and the ashless antiwear compound are significantly increased or decreased. This is also demonstrated by comparing Comparative sample 14 to Inventive samples 20-22.

Fluids containing the dispersants comprising the olefin copolymer having a relatively smaller Mn, in combination with an ashless antiwear compound, would also exhibit improved frictional properties. For example, if Dispersant “E” is blended in a base oil with ashless antiwear compound “M”, the lubricant composition would exhibit a lower friction coefficient than a fluid containing a similar Mn polyisobutylene dispersant in combination with the same ashless antiwear agent “M”.

In addition, fluids comprising an olefin copolymer dispersant that has been post-treated, in combination with an ashless antiwear compound, would also exhibit improved frictional properties. For example, if Dispersant “F” is blended in a base oil with ashless antiwear agent “M”, the lubricant composition would exhibit a lower friction coefficient than a fluid containing a similar Mn polyisobutylene dispersant post-treated with boric acid and maleic anhydride, in combination with the same ashless antiwear agent “M”.

Friction Coefficients for Base Oil Comprising Dispersants and Detergents

Table 11 provides the friction coefficients for lubricating compositions containing a detergent and either a polyisobutylene dispersant or a olefin copolymer dispersant. Each dispersant was treated at an amount to deliver the noted level of nitrogen in Table 11 and each detergent was treated in an amount to deliver the noted TBN in Table 11.

TABLE 11

Detergent
Dispersant

treated to
treated to deliver

deliver the
the noted amount

noted amount
of Nitrogen
Friction

Samples
of TBN
(ppm N)
Coefficient

Inv 23
A + B + Q
5.4
754
0.138

Inv 24
A + B + R
4.5
754
0.147

Inv 25
A + B + S
7.2
754
0.153

Inv 26
A + B + T
3.0
754
0.141

Comp
A + H + U
0.5
720
0.172

15

Inv 27
A + C + U
0.5
720
0.142

Inv 28
A + C + Q
5.4
720
0.137

Inv 29
A + C + Q
12.0
185
.162

Inv 30
A + C + Q
0.3
185
.152

Inv 31
A + C + Q
12.0
1440
.151

Inv 32
A + C + S
0.4
1440
.134

Inv 33
A + C + S
0.4
1440
.132

As shown in Table 11, the lubricant compositions containing base oil and the olefin copolymer dispersant in combination with a detergent exhibit lower friction coefficients when compared to fluids containing similar molecular weight polyisobutylene dispersants in combination with the detergent. This inventive effect is maintained in lubricant compositions containing independently relatively high and low treat rates of the olefin copolymer dispersant and relatively high and low treat rates of detergent.

Fluids comprising the dispersants comprising the olefin copolymer having a relatively smaller Mn, in combination with a detergent, would also exhibit improved frictional properties. For example, if Dispersant “E” is blended in a base oil with detergent “Q”, the lubricant composition would exhibit a lower friction coefficient than a fluid containing a similar Mn polyisobutylene dispersant in combination with the same detergent “Q”.

In addition, fluids comprising the olefin copolymer dispersant that has been post-treated, in combination with a detergent, would also exhibit improved frictional properties. For example, if Dispersant “F” is blended in a base oil with detergent “Q”, the lubricant composition would exhibit lower a friction coefficient than a fluid containing a similar Mn polyisobutylene dispersant post-treated with boric acid and maleic anhydride, in combination with the same detergent “Q”.

Friction Coefficients for Base Oil Comprising Dispersants and Extreme Pressure Agents

Table 12 provides the friction coefficients for lubricating compositions containing an extreme pressure agent and either a polyisobutylene dispersant or an olefin copolymer dispersant. Each extreme pressure agent was treated at the amount to deliver the noted level of sulfur in Table 12. Unless otherwise noted, each dispersant was treated at an amount to deliver 720 ppm nitrogen to the fluid.

TABLE 12

Extreme Pressure

Agent treated to

deliver the noted

amount of Sulfur
Friction

Samples
(ppm S)
Coefficient

Inv 34
A + B + V
762
0.15

(B treated at an amount

to deliver 754 ppm N)

Comp 16
A + H + W
3500
0.169

Inv 35
A + C + W
3500
0.145

Inv 36
A + C + W
10,500
.140

(C treated at an amount

to deliver 180 ppm N)

Inv 37
A + C + W
350
.143

(C treated at an amount

to deliver 1440 ppm N)

Comp 17
A + H + X
4600
0.157

Inv 38
A + C + X
4600
0.126

Comp 18
A + H + Y
4800
0.151

Inv 39
A + C + Y
4800
0.122

Inv 40
A + C + V
3810
.124

(C treated at an amount

to deliver 180 ppm N)

Inv 41
A + C + V
127
.134

(C treated at an amount

to deliver 1440 ppm N)

As shown in Table 12, the lubricant compositions containing base oil and the olefin copolymer dispersant in combination with extreme pressure agents exhibit lower friction coefficients when compared to fluids containing similar molecular weight polyisobutylene dispersants in combination with the extreme pressure agents. This inventive effect is maintained in lubricant compositions containing independently relatively high and low treat rates of the olefin copolymer dispersant and relatively high and low treat rates of extreme pressure agent. For example, when compared to Comparative sample 16, Inventive samples 35-37 demonstrate that friction coefficients are lowered even when the treat rates of the olefin copolymer dispersant and the extreme pressure agent are significantly increased or decreased.

Fluids comprising the dispersants comprising the olefin copolymer having a relatively smaller Mn, in combination with an extreme pressure agent would also exhibit improved frictional properties. For example, if Dispersant “E” is blended in a base oil with extreme pressure agent “Y”, the lubricant composition would exhibit lower friction coefficient than a fluid containing a similar Mn polyisobutylene succinimide dispersant in combination with the same extreme pressure agent “Y”.

In addition, fluids comprising an olefin copolymer dispersant that has been post-treated, in combination with an extreme pressure agent also exhibit improved frictional properties. For example, if Dispersant “F” is blended in a base oil with extreme pressure agent “Y”, the lubricant composition would exhibit lower friction coefficient than a fluid containing a similar Mn polyisobutylene dispersant post-treated with boric acid and maleic anhydride, in combination with the same extreme pressure agent “Y”.

Friction Coefficients for Base Oil Comprising Dispersants and Friction Modifiers

Table 13 provides the friction coefficients for lubricating compositions containing a friction modifier and either a polyisobutylene dispersant or an olefin copolymer dispersant. Each friction modifier was treated at the amount noted in Table 13. Unless otherwise noted, each dispersant was treated at an amount to deliver 720 ppm nitrogen to the fluid.

TABLE 13

Friction Modifier

Treat rate
Friction

Samples
(wt %)
Coefficient

Comp 19
A + H + AA
0.3
0.152

Inv 42
A + C + AA
0.3
0.144

Inv 43
A + C + AA
3.0
0.136

(C treated at an amount

to deliver 1440 ppm N)

Comp 20
A + H + BB
0.3
0.147

Inv 44
A + C + BB
0.3
0.135

Comp 21
A + H + CC
0.3
0.153

Inv 45
A + C + CC
0.3
0.140

Comp 22
A + H + DD
0.3
0.149

Inv 46
A + C + DD
0.3
0.141

Comp 23
A + H + EE
0.3
0.153

Inv 47
A + C + EE
0.3
0.123

Comp 24
A + H + FF
0.3
0.169

Inv 48
A + C + FF
0.3
0.135

Comp 25
A + H + GG
0.3
0.173

Inv 49
A + C + GG
0.3
0.153

Comp 26
A + H + HH
0.5
0.178

(H treated at an amount

to deliver 756 ppm N)

Inv 50
A + C + HH
0.5
0.136

Inv 51
A + C + HH
3.0
0.067

(C treated at an amount

to deliver 180 ppm N)

Inv 52
A + C + HH
0.1
0.134

(C treated at an amount

to deliver 1440 ppm N)

Comp 27
A + H + Z
0.2
0.152

(H treated at an amount

to deliver 1080 ppm N)

Inv 53
A + C + Z
0.2
0.141

(C treated at an amount

to deliver 1080 ppm N)

Inv 54
A + C + Z
3.0
0.097

(C treated at an amount

to deliver 180 ppm N)

Inv 55
A + C + Z
0.1
0.146

(C treated at an amount

to deliver 1440 ppm N)

As shown in Table 13, the lubricant compositions containing base oil and olefin copolymer dispersants in combination with friction modifiers exhibit lower friction coefficients when compared to fluids containing similar molecular weight polyisobutylene dispersants in combination with the friction modifiers. This inventive effect is maintained in lubricant compositions containing independently relatively high and low treat rates of the olefin copolymer dispersant and relatively high and low treat rates of friction modifier. For example, when compared to Comparative sample 19, Inventive samples 42-43 demonstrate that friction coefficients are lowered even when the treat rates of the olefin copolymer dispersant and the extreme pressure agent are significantly increased or decreased. This is also demonstrated by comparing Comparative sample 26 to Inventive samples 50-52 and comparing Comparative sample 27 to Inventive samples 53-55.

Fluids comprising the dispersants comprising the olefin copolymer having a relatively smaller Mn, in combination with a friction modifier also exhibit improved frictional properties. For example, if Dispersant “E” is blended in a base oil with friction modifier “BB”, the lubricant composition would exhibit lower friction coefficient than a fluid containing a similar Mn polyisobutylene dispersant in combination with the friction modifier “BB”.

In addition, fluids comprising the olefin copolymer dispersant that has been post-treated, in combination with an extreme pressure agent also exhibit improved frictional properties. For example, if Dispersant “F” is blended in a base oil with friction modifier “BB” the lubricant composition would exhibit lower friction coefficient than a fluid containing a similar Mn polyisobutylene dispersant post-treated with boric acid and maleic anhydride, in combination with the same friction modifier “BB”.

Friction Coefficients for Base Oil Comprising Dispersants. Friction Modifiers, and ZDDPs

Table 14 provides the friction coefficients for lubricating compositions containing base oil, ZDDP, friction modifier, and either a polyisobutylene dispersant or an olefin copolymer dispersant. In Inventive samples 56-59, Dispersant “C” was treated at 3.8 wt %, each ZDDP was treated at an amount to deliver approximately 800 ppm phosphorus to the fluid, and Friction Modifier “Z” was treated at 0.5 wt %. Inventive samples 60-61, took fully formulated GF-5 capable lubricant compositions, and replaced the dispersants therein with an olefin copolymer dispersant described herein so as to provide equal TBN contribution to the fluid. Inventive sample 60 contained Dispersant “C” and Inventive sample 61 contained Dispersant “B”. Inventive samples 60-61 also contained multiple ZDDPs, which in total, delivered approximately 770 ppm phosphorus to the fluid and multiple friction modifiers at a combined treat rate of approximately 0.8 wt %.

TABLE 14

Friction

Samples
Coefficient

Inv 56
A + C + I + Z
0.121

Inv 57
A + C + J + Z
0.122

Inv 58
A + C + K + Z
0.124

Inv 59
A + C + L + Z
0.130

Inv 60
Fully formulated
0.129

Inv 61
Fully formulated
0.121

As shown in Table 14, the lubricant compositions containing base oil and the olefin copolymer dispersants in combination with ZDDPs and friction modifiers lower friction coefficient. The inventive effect shown is maintained in fully formulated lubricant compositions.

While several embodiments of the present invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present disclosure. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the compositions and methods described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the disclosure may be practiced otherwise than as specifically described and claimed. The present disclosure is directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present disclosure.

All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

Definitions

The following definitions of terms are provided in order to clarify the meanings of certain terms as used herein.

The terms “oil composition,” “lubrication composition,” “lubricating oil composition,” “lubricating oil,” “lubricant composition,” “lubricating composition,” “fully formulated lubricant composition,” “lubricant,” are considered synonymous, fully interchangeable terminology referring to the finished lubrication product comprising a major amount of a base oil plus a minor amount of an additive composition.

As used herein, the terms “additive package,” “additive concentrate,” “additive composition,” are considered synonymous, fully interchangeable terminology referring the portion of the lubricating oil composition excluding the major amount of base oil stock mixture. The additive package may or may not include the viscosity index improver or pour point depressant.

As used herein, the term “hydrocarbyl substituent” or “hydrocarbyl group” is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include: (a) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and alicyclic-substituted aromatic substituents, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (e.g., two substituents together form an alicyclic moiety); (b) substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this disclosure, do not alter the predominantly hydrocarbon substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, amino, alkylamino, and sulfoxy); and (c) hetero substituents, that is, substituents which, while having a predominantly hydrocarbon character, in the context of this disclosure, contain other than carbon in a ring or chain otherwise composed of carbon atoms. Heteroatoms may include sulfur, oxygen, and nitrogen, and encompass substituents such as pyridyl, furyl, thienyl, and imidazolyl. In general, no more than two, for example, no more than one, non-hydrocarbon substituent will be present for every ten carbon atoms in the hydrocarbyl group; typically, there will be no non-hydrocarbon substituents in the hydrocarbyl group.

As used herein, the term “percent by weight,” unless expressly stated otherwise, means the percentage the recited component represents to the weight of the entire composition.

The terms “soluble,” “oil-soluble,” or “dispersible” used herein may, but does not necessarily, indicate that the compounds or additives are soluble, dissolvable, miscible, or capable of being suspended in the oil in all proportions. The foregoing terms do mean, however, that they are, for instance, soluble, suspendable, dissolvable, 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 term “alkyl” as employed herein refers to straight, branched, cyclic, and/or substituted saturated chain moieties.

The term “alkenyl” as employed herein refers to straight, branched, cyclic, and/or substituted unsaturated chain moieties.

The term “aryl” as employed herein refers to single and multi-ring aromatic compounds that may include alkyl, alkenyl, alkylaryl, amino, hydroxyl, alkoxy, halo substituents, and/or heteroatoms including, but not limited to, nitrogen, oxygen, and sulfur.

The term “monomer moiety” as used herein refers to an ethylene or an alpha-olefin monomer incorporated into a copolymer.

The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

When the word “about” is used herein in reference to a number, it should be understood that still another embodiment of the invention includes that number not modified by the presence of the word “about.”

It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited unless suggested by the context of the method.

In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedure, Revision 07.2015, Section 2111.03.

The details and advantages of the disclosure may be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that the descriptions herein are exemplary and explanatory only and are not restrictive of the disclosure, as claimed.

LUBRICANT COMPOSITIONS COMPRISING OLEFIN COPOLYMER DISPERSANTS IN COMBINATION WITH ADDITIVES

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CROSS REFERENCE TO RELATED APPLICATION