Lubricating composition for lubricating an internal combustion engine and method of lubricating an internal combustion engine

Abstract

The present invention provides, inter alia, a method of producing a low molecular weight dispersant polymethacrylate polymer ("LMW DPMA") and the LMW DPMA itself, as well as the use of the LMW DPMA in a lubricating composition, and a method for lubricating an internal combustion engine, as disclosed herein.

Description

BACKGROUND

[0001] The present invention provides, inter alia, a process for producing a low molecular weight dispersant polymethacrylate polymer ("LMW DPMA") and the LMW DPMA itself, and the use of the LMW DPMA in a lubricating composition, and a method for lubricating an internal combustion engine.

[0002] Low viscosity fluids are desirable for improved fuel economy / efficiency. One of the ingredients that has the most impact on the viscosity of formulated fluids is the dispersant - usually because the dispersant is present in the fluid at the highest treat rate, and because the dispersant is a "large" molecule (dispersants and detergents are considered "large molecules", anti-wear, antioxidant, friction modifiers are generally considered small molecules).

[0003] One way to impact the viscosity of a fluid is to lower the viscosity of the dispersant. However, many conventional methods of lowering the contribution of the dispersant to the final fluid viscosity negatively impact cleanliness. The present invention allows for the synthesis of lower viscosity dispersants without negatively impacting the cleanliness of the fluid.

[0004] Typically, the hydrophobic portion of the dispersant is made from a polymer or copolymer of low molecular weight olefins, i.e., ethylene, propylene, isobutylene. Common ways of functionalizing these hydrocarbon backbones include free radical grafting, chlorine-promoted or thermal "ene" reactions to functionalize the hydrocarbon with an acylating agent. Control of the functionalization reaction is challenging for these types of reactions. In many cases, a mixture is formed where some molecules have one, two, or more acylating agents, while other molecules are not functionalized. The resulting acylating agent is then functionalized with an amine. The unreacted olefin only serves as a diluent, making the yield of dispersant in the final composition less than desired.

[0005] Methacrylate polymers are typically prepared by conventional free radical polymerization (FRP). This involves contacting the monomers with a species capable of generating free radicals (initiator) and a chain transfer agent (CTA), which is typically a thiol species such as decanethiol. The CTA terminates growing polymer chains by allowing the terminal polymer radical to abstract a hydrogen radical from the weak S-H bond of the CTA. Thus, the polymer molecular weight can be controlled by the amount of CTA provided to the polymerization reaction. A drawback of this method is the need for a relatively large amount of sulfur-containing CTA to produce short, low molecular weight polymer chains. Residual sulfur in the product so formed is undesirable, and while sulfur removal is possible, it is not economically attractive.

[0006] It would be advantageous to prepare low molecular weight methacrylate polymers in a more viable approach. It would also be advantageous to prepare methacrylate polymers capped with nitrogen-containing compounds to make dispersant-like molecules (i.e., molecules with a polar head and a relatively non-polar tail) that are low in viscosity and do not negatively impact the cleanliness of the formulation. SUMMARY

[0007] Catalytic chain transfer polymerization (CCTP) allows for the preparation of very low molecular weight polymers without the problems associated with the use of sulfur-containing CTAs. CCTP catalysts are essentially sulfur-free, used in small amounts, and are more efficient at chain transfer.

[0008] Using catalytic chain transfer polymerization, it is possible to synthesize a hydrophobic backbone uniquely positioned to react only once at the hydrophilic head of the molecule. In theory, end-functionalization can be accomplished in such a way that there are no unreacted hydrocarbon backbones and every polymer chain is reacted with an amine polar head group.

[0009] Thus, the disclosed technology solves the problem of preparing low molecular weight polymethacrylates by preparing the polymers with catalytic chain transfer agents.

[0010] The disclosed technology also solves the problem of obtaining low molecular weight dispersant polymethacrylates by reacting low molecular weight polymethacrylates prepared with catalytic chain transfer agents with nitrogen-containing compounds.

[0011] One aspect of the technology relates to a low molecular weight dispersant polymethacrylate polymer ("LMWDPMA") encompassing the reaction product of a vinyl-terminated polymethacrylate polymer having a number average molecular weight of from about 1000 to about 5000 with a nitrogen-containing group.

[0012] The LMWDPMA can be used in a lubricant composition having an oil of lubricating viscosity and other optional performance additives.

[0013] The technology also provides a method of lubricating an internal combustion engine by supplying to the internal combustion engine a lubricating composition containing the LMWDPMA.

[0014] Further, the technology includes a method for preparing the LMWDPMA by first preparing a vinyl-terminated polymethacrylate polymer by catalytic chain transfer polymerization; and then reacting the vinyl-terminated polymethacrylate polymer with a nitrogen-containing group in the presence of microwave radiation. DETAILED DESCRIPTION

[0015] The present invention provides, inter alia, a method of producing a low molecular weight dispersant polymethacrylate polymer ("LMW DPMA") and the LMW DPMA itself, and the use of the LMW DPMA in a lubricating composition, and a method for lubricating an internal combustion engine, as disclosed herein.

[0016] Low molecular weight dispersant polymethacrylate polymers

[0017] The technology provides a LMW DPMA composed of a polymethacrylate backbone and terminated by a nitrogen-containing group.

[0018] The term "low molecular weight" with respect to the LMW DPMA is a number average molecular weight ("Mn") of about 500 to about 10,000, or about 750 to about 7,500, or even about 1000 to about 5000, or 1500 to 4000, or 1750 to 3000, as measured by gel permeation chromatography ("GPC"). All chromatographic measurements were performed using an Agilent 390-LC MDS instrument equipped with a differential refractive index and dual wavelength UV detectors. Poly(methyl) methacrylate and polystyrene standards were used for calibration.

[0019] In one embodiment, the LMW DPMA can be prepared as a reaction product of a vinyl-terminated polymethacrylate polymer with a nitrogen-containing group.

[0020] The vinyl-terminated polymethacrylate polymer can be synthesized by catalytic chain transfer polymerization ("CCTP"), in which a desired methacrylate monomer is reacted with a catalytic amount of a chain transfer agent. The catalyst interacts with the terminal free radical on the growing polymer chain to form a Co(III)-H complex and a macromonomer with a useful terminal olefin functionality, as shown in Formula I below:

[0021]

[0022] wherein R1is an alkyl group having 1 to 24 carbon atoms; and wherein n is an integer from 3 to 30.

[0023] The desired monomer for preparing the vinyl-terminated polymethacrylate polymer can comprise, for example, a mixture of methacrylate monomers including methacrylate monomers having alkyl groups of different lengths. The methacrylate monomers can contain alkyl groups that are linear or branched groups or aromatic groups. The alkyl groups can contain 1 to 24 carbon atoms, for example, 1 to 20 carbon atoms.

[0024] The vinyl-terminated polymethacrylate polymers described herein can be formed from monomers derived from saturated alcohols, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-methylpentyl methacrylate, 2-propylheptyl methacrylate, 2-butyloctyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, nonyl methacrylate, isooctyl methacrylate, isononyl methacrylate, 2-tert-butylheptyl methacrylate, 3-isopropylheptyl methacrylate, decyl methacrylate, undecyl methacrylate, 5-methylundecyl methacrylate, dodecyl methacrylate, 2-methyldodecyl methacrylate, and methylpropanediol. Tridecyl methacrylate, 5-methyltridecyl methacrylate, tetradecyl methacrylate, pentadecyl methacrylate, hexadecyl methacrylate, 2-methylhexadecyl methacrylate, heptadecanyl methacrylate, 5-isopropylheptadecanyl methacrylate, 4-tert-butyloctadecyl methacrylate, 5-ethyloctadecyl methacrylate, 3-isopropyloctadecyl methacrylate, octadecyl methacrylate, nonadecanyl methacrylate, eicosyl methacrylate; methacrylates derived from unsaturated alcohols, such as oleyl methacrylate; and cycloalkyl methacrylates, such as 3-vinyl-2-butylcyclohexyl methacrylate or borneol methacrylate.

[0025] Other examples of monomers used to prepare vinyl-terminated polymethacrylate polymers may include alkyl methacrylates having long-chain alcohol-derived groups, which can be obtained, for example, by reacting methacrylic acid (through direct esterification) or methyl methacrylate (through transesterification) with long-chain fatty alcohols. These fatty alcohols include those from Sasol. 1620 10. 810 12. 1012EE 1014CDC 1214、 1214GC 1214HA 1216 and 125; Shell AG 91. twenty three, 25. 45 and 135; BASF's C13-C15 alcohol, isotridecanol, and Kao Corporation 2465, 2470, 8655; and Ecogreen Oleochemicals' ECO- 1® 80, 24, 26, 28 and 68. Additional examples of monomers include alkyl methacrylates having branched alcohol-derived groups, which can be obtained, for example, by reacting methacrylic acid (by direct esterification) or methyl methacrylate (by transesterification) with Guerbet alcohols. Examples of Guerbet alcohols include 2-butyl octanol, 2-butyl decanol, 2-hexyl octanol, 2-hexyl decanol, 2-octyl decanol, 2-hexyl dodecanol, 2-octyl dodecanol, 2-decyl tetradecanol, 2-dodecyl hexadecanol, and 2-tetradecyl octadecanol.

[0026] Aromatic monomers can also be used to make the vinyl-terminated polymethyl methacrylate polymer and can include, for example, benzyl methacrylate. In another embodiment, the aromatic monomer can be selected from phenyl methacrylate, phenyl propyl methacrylate, or styrene. It is contemplated that other oil-insoluble methacrylate monomers that can polymerize in oil can also be used. Mixtures of these and other oil-insoluble monomers can also be used in the present application.

[0027] As mentioned above, the vinyl-terminated polymethyl methacrylate polymer is synthesized by catalytic chain transfer polymerization (“CCTP”), in which the desired monomer is reacted with a catalytic amount of a chain transfer agent. Examples of catalytic chain transfer agents can include, but are not limited to, low-spin Co(II) complexes, such as cobaloxime [J. Am. Chem. Soc., 1984, 106, 5197-5202] and derivatives thereof.

[0028] Once prepared, the vinyl-terminated polymethyl methacrylate polymer can then be reacted with a nitrogen-containing group to form the LMW DPMA. The use of CCTP to prepare the vinyl-terminated polymethyl methacrylate polymer results in a polymer with a single functional chain end at which the nitrogen-containing group is attached, in contrast to the free radical polymerization typically employed, which does not result in a functional chain end. The LMW DPMA can be represented by Formula II below:

[0029]

[0030] wherein R1and n are as described above, and X is a nitrogen-containing group, as discussed further below.

[0031] In some embodiments, the addition of the nitrogen-containing group to the vinyl-terminated polymethylacrylate polymer can occur in the presence of microwave radiation. It has been found that such addition in the presence of microwave radiation significantly shortens the reaction time (e.g., 100% conversion after 1 hour), as compared to a simple Michael addition, which is typically applied, which results in a longer reaction period (e.g., 100% conversion after 24 hours).

[0032] Nitrogen-containing compounds can include aromatic amines, such as those in which the carbon atoms of the aromatic ring structure are directly connected to the amino nitrogen. The amines can be monoamines or polyamines. The aromatic ring will typically be a monocyclic aromatic ring (i.e., a ring derived from benzene), but can include fused aromatic rings, such as those derived from naphthalene. Examples of aromatic amines include aniline, N-alkylanilines (such as N-methylaniline and N-butylaniline), di-(p-methylaniline), naphthylamine, 4-aminodiphenylamine, N,N-dimethylaniline, 4-(4-nitrophenylazo)aniline (fast orange 3), sulfadimethoxine, 4-phenoxyaniline, 3-nitroaniline, 4-aminoacetanilide, 4-amino-2-hydroxy-benzoic acid phenyl ester (phenylamino salicylate), N-(4-amino-5-methoxy-2-methyl-phenyl)-benzamide (fast violet B), N-(4-amino-2,5-dimethoxy-phenyl)-benzamide (fast blue RR), N-(4-amino-2,5-diethoxy-phenyl)-benzamide (fast blue BB), N-(4-aminophenyl)-benzamide, and 4-phenylazobenzenamine. Other examples include p-ethoxyaniline, p-dodecylaniline, cyclohexyl-substituted naphthylamine, and thienyl-substituted aniline. Examples of other suitable aromatic amines include amino-substituted aromatic compounds and amines in which the amine nitrogen is part of an aromatic ring, such as 3-aminoquinoline, 5-aminoquinoline, and 8-aminoquinoline. Also included are aromatic amines such as 2-amino benzimidazole, which contains one secondary amino group directly attached to an aromatic ring and a primary amino group attached to an imidazole ring. Other amines include N-(4-anilinophenyl)-3-aminobutyramide (i.e., φ-NH-φ-NH-COCH2CH(CH3)NH2). Additional aromatic amines include aminocarbazole, aminoinde, aminopyrrole, amino-indazolinone, aminophthaline, mercaptotriazole, aminophenothiazine, aminopyridine, aminopyrazine, aminopyrimidine, pyridine, pyrazine, pyrimidine, aminothiadiazole, aminothiathiadiazole, and aminobenzotriazole. Other suitable amines include 3-amino-N-(4-anilinophenyl)-N-isopropylbutyramide and N-(4-anilinophenyl)-3-{(3-aminopropyl)-(cocoalkyl)amino}butyramide. Other aromatic amine intermediates that can be used include various aromatic amine dyes intermediates containing multiple aromatic rings linked by, for example, amide structures. Examples include materials of the general structure φ-CONH-φ-NH2, in which the phenyl groups can be substituted. Suitable aromatic amines include those in which the amine nitrogen is a substituent on an aromatic carboxylic acid compound, i.e., the nitrogen is not within an aromatic ring sp 2 hybridized.

[0033] The nitrogen-containing compounds can also include non-aromatic amines, or in other words, amines in which the amino nitrogen is not directly attached to a carbon atom of an aromatic ring, or amines in which the amine nitrogen is not part of an aromatic ring, or amines in which the amine nitrogen is not a substituent on an aromatic carboxylic compound. In some cases, such non-aromatic amines can be considered aliphatic or cycloaliphatic. Such amines can be straight-chained, or branched or functionalized with certain functional groups. The non-aromatic amines can include monoamines having, for example, 1 to 8 carbon atoms, such as methylamine, ethylamine, and propylamine, as well as various higher carbon amines. Diamines or polyamines can also be used, and will typically have only a single primary amino group. Examples include dimethylaminopropylamine, diethylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, dibutylaminoethylamine, 1-(2-aminoethyl)piperidine, 1-(2-aminoethyl)pyrrolidone, N,N-dimethylethylamine; 3-(dimethylamino)-1 -propylamine; O-(2-aminopropyl)-O'-(2-methoxyethyl)polypropylene glycol; N,N-dimethyldipropylene triamine, aminoethylmorpholine, 3-morpholinopropylamine, aminoethyl ethylene urea, and aminopropylmorpholine.

[0034] In certain embodiments, the non-aromatic amines can be used alone or in combination with each other or in combination with the aromatic amines. In some embodiments, the amount of aromatic amines can be trace amounts compared to the amount of non-aromatic amines, or in certain cases, the composition can be substantially free or free of aromatic amines.

[0035] In certain embodiments, the aromatic amines can be used alone or in combination with each other or in combination with the non-aromatic amines. In some embodiments, the amount of non-aromatic amines can be trace amounts compared to the amount of aromatic amines, or in certain cases, the composition can be substantially free or free of non-aromatic amines.

[0036] The lubricating composition of the present invention includes 0.1 wt % to 10 wt %, or 0.25 wt % to 8 wt %, or 0.5 wt % to 5 wt % of the LMW DPMA, as described herein.

[0037] Lubricant composition

[0038] The present technology includes lubricant compositions containing the above-described LMW DPMA, an oil of lubricating viscosity, and other optional performance additives suitable for use in engine oil lubricants.

[0039] Oil of lubricating viscosity

[0040] The lubricating composition includes an oil of lubricating viscosity. Such oils include natural and synthetic oils, oils derived from hydrocracking, hydrogenation, and hydrofmishing, unrefined, refined, re-refined oils, or mixtures thereof. A more detailed description of unrefined, refined, and re-refined oils is provided in International Publication WO 2008 / 147704 at paragraphs

[0054] to

[0056] (similar disclosure is provided in U.S. Patent Application 2010 / 197536, see

[0072] to

[0073] ). A more detailed description of natural and synthetic lubricating oils is provided in WO 2008 / 147704 at paragraphs

[0058] to

[0059] (similar disclosure is provided in U.S. Patent Application 2010 / 197536, see

[0075] to

[0076] ). Synthetic oils can also be produced by Fischer-Tropsch reactions, and typically can be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oil can be made by a Fischer-Tropsch gas-to-liquid synthetic procedure, among others.

[0041] Oils of lubricating viscosity can also be defined as specified in Section 1.3, Subtitle 1.3. "Base Stock Categories," of the April 2008 version of "Appendix E - API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils." The API Guidelines are also summarized in U.S. Patent 7,285,516 (see column 11, line 64 to column 12, line 10).

[0042] In one embodiment, the oil of lubricating viscosity can be an API Group I to Group IV mineral oil, ester, or synthetic oil, or mixtures thereof. In one embodiment, the oil of lubricating viscosity can be an API Group II, Group III, Group IV mineral oil, ester, or synthetic oil, or mixtures thereof.

[0043] The amount of oil of lubricating viscosity present is typically the balance remaining after subtracting from 100 wt % the sum of the amounts of the additives of the application and other performance additives.

[0044] The lubricating composition can be in the form of a concentrate and / or a fully formulated lubricant. If the lubricating composition of the present application, including the additives disclosed herein, is in the form of a concentrate, which can be combined with additional oil to fully or partially form a finished lubricant, the weight ratio of these additives to oil of lubricating viscosity and / or to diluent oil includes the range of 1 :99 to 99: 1 or 80:20 to 10:90. Typically, the lubricating composition of the present application includes at least 50 wt%, or at least 60 wt%, or at least 70 wt%, or at least 80 wt% of oil of lubricating viscosity.

[0045] In the present application, the lubricating composition includes a base oil having a kinematic viscosity, measured at 100°C, of 3.0 square meters / second to 6.0 square meters / second, for example, 3.4 square meters / second to 5.6 square meters / second.

[0046] Other performance additives

[0047] The lubricating composition can be prepared by adding the LMW DPMA to an oil of lubricating viscosity, optionally in the presence of other performance additives, as described below.

[0048] The lubricating composition of the present application optionally includes other performance additives. The other performance additives include at least one of the following: metal deactivators, viscosity improvers, detergents, friction modifiers, corrosion inhibitors, dispersants, extreme pressure agents, antioxidants, foam inhibitors, demulsifiers, pour point depressants, seal swell agents, and mixtures thereof. Typically, a fully formulated lubricating oil will contain one or more of these performance additives.

[0049] In one embodiment, the present application provides a lubricating composition further including an overbased metal-containing detergent. The metal of the metal-containing detergent can be zinc, sodium, calcium, barium, or magnesium. Typically, the metal of the metal-containing detergent can be sodium, calcium, or magnesium.

[0050] The overbased metal-containing detergent can be selected from the group consisting of non-sulfur phenate-containing, sulfur phenate-containing, sulfonate, salicylic alcoholate, salicylate, and mixtures thereof or borated equivalents thereof. The overbased detergent can be borated with a borating agent, such as boric acid.

[0051] The lubricating composition can further include a zinc dialkyldithiophosphate anti-wear agent. Zinc dialkyldithiophosphates are known in the art. Examples of zinc dithiophosphates include zinc isopropyl methyl pentyl dithiophosphate, zinc isopropyl isooctyl dithiophosphate, zinc di(cyclohexyl) dithiophosphate, zinc isobutyl 2- ethylhexyl dithiophosphate, zinc isopropyl 2-ethylhexyl dithiophosphate, zinc isobutyl isoamyl dithiophosphate, zinc isopropyl n-butyl dithiophosphate, and combinations thereof. The zinc dialkyldithiophosphate can be present in an amount that provides 0 wt% to 0.03 wt% phosphorus to the lubricating composition. In one embodiment, the lubricating composition can be free or substantially free of zinc dialkyldithiophosphate.

[0052] In other embodiments, the lubricating composition includes an antioxidant, wherein the antioxidant includes a phenolic or amine antioxidant or mixtures thereof. The antioxidant includes a diaryl amine, an alkylated diaryl amine, a hindered phenol, or mixtures thereof. When present, the antioxidant is present from 0.1 wt% to 3 wt%, or from 0.5 wt% to 2.75 wt%, or from 1 wt% to 2.5 wt% of the lubricating composition.

[0053] In one embodiment, the lubricant composition can include a friction modifier. The friction modifier can be selected from the group consisting of long chain fatty acid derivatives of amines, long chain fatty esters, or derivatives of long chain fatty epoxides; fatty imidazolines; amine salts of alkyl phosphates; fatty alkyl tartrates; fatty alkyl tartrimides; fatty alkyl tartramides; fatty glycolates; and fatty oxamides. The friction modifier can be present from 0 wt% to 6 wt%, or from 0.01 wt% to 4 wt%, or from 0.05 wt% to 2 wt%, or from 0.1 wt% to 2 wt% of the lubricating composition. As used herein, the term "fatty alkyl" or "fatty" with respect to the friction modifier means a carbon chain, typically a straight carbon chain, having from 10 to 22 carbon atoms.

[0054] Another class of additives that can be employed in the lubricant composition includes oil-soluble titanium compounds as disclosed in US 7,727,943 and US 2006 / 0014651. The oil-soluble titanium compounds can function as an additional anti-wear agent, friction modifier, antioxidant, deposit control additive, or more than one of these functions. In one embodiment, the oil-soluble titanium compound is a titanium (IV) alkoxide. The titanium alkoxide is formed from a monohydric alcohol, a polyhydric alcohol, or a mixture thereof. The monohydric alkoxide can have from 2 to 16, or from 3 to 10 carbon atoms. In one embodiment, the titanium alkoxide is titanium (IV) isopropoxide. In one embodiment, the titanium alkoxide is titanium (IV) 2-ethylhexoxide. In one embodiment, the titanium compound includes an alkoxide of a vicinal 1,2-diol or polyol. In one embodiment, the 1,2- vicinal diol includes a fatty acid monoester of glycerol, typically the fatty acid is oleic acid. In one embodiment, the oil-soluble titanium compound is a titanium carboxylate. In other embodiments, the titanium carboxylate (IV) is titanium neodecanoate.

[0055] The lubricant composition can contain an extreme pressure agent. Oil-soluble extreme pressure (EP) agents include sulfur- and chlorine-sulfur-containing EP agents, CS2 derivatives of dimercaptothiadiazoles or dispersants, chlorinated hydrocarbon EP agents, and derivatives of phosphorus EP agents. Examples of such EP agents include chlorinated waxes; sulfurized olefins (such as sulfurized isobutylene), hydrocarbyl-substituted 2,5-dimercapto-l,3,4-thiadiazoles, or oligomers thereof, organosulfides and polysulfides such as benzyl disulfide, bis-(chlorobenzyl) disulfide, dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized alkylphenol, sulfurized dipentene, sulfurized terpene, and sulfurized Diels-Alder adducts; phosphorus-sulfurized hydrocarbons such as the reaction product of phosphorus sulfide with turpentine or methyl oleate; phosphorus esters such as dihydrocarbyl and trihydrocarbyl phosphites, for example, dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite; dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite, and polypropylene-substituted phenol phosphite; metal thiocarbamates such as zinc dioctyldithiocarbamate and barium heptylphenol diacid; amine salts of alkyl and dialkyl phosphates or derivatives, including, for example, the amine salt of the reaction product of a dialkyldithiophosphoric acid with propylene oxide followed by further reaction with P2O5; and mixtures thereof (as described in US 3,197,405).

[0056] Foam inhibitors that can be used in the compositions of the present application include polysiloxanes, copolymers of ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate; demulsifiers including fluorinated polysiloxanes, trialkyl phosphates, polyethylene glycols, polyethylene oxides, polypropylene oxides, and (ethylene oxide-propylene oxide) polymers.

[0057] Pour point depressants that can be used in the compositions of the present application include polyalphaolefins, esters of maleic anhydride-styrene copolymers, polymethacrylates, polyacrylates, or polyacrylamides.

[0058] Demulsifiers include trialkyl phosphate esters, as well as various polymers and copolymers of ethylene glycol, oxirane, propylene oxide, or mixtures thereof.

[0059] Metal deactivators include derivatives of benzotriazole (typically tolyltriazole), 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole, or 2-alkyldithiobenzothiazole. Metal deactivators can also be described as corrosion inhibitors.

[0060] Seal swell agents include the cyclobutene sulfone derivative Exxon Necton-37 TM (FN 1380) and Exxon Mineral Seal Oil TM (FN 3200).

[0061] Other seal swell agents include those represented by compounds of Formula (A)

[0062] (A)

[0063] wherein: R 1 and R 2 each independently is a hydrocarbyl group containing from about 4 to about 18 carbon atoms; p and q each independently are 0 or an integer from 1 to 3, and the sum of p and q is 1, 2, 3, 4, 5, or 6. Such compounds are further discussed in WO 2017 / 205270, published November 30, 2017.

[0064] Other seal swell agents include those represented by compounds of Formula (B)

[0065] (B)

[0066] wherein x is 0 or 1, and R 1 is a hydrocarbyl group containing from about 4 to about 18 carbon atoms. Such compounds are further discussed in WO 2017 / 205271, published November 30, 2017.

[0067] Other seal swell agents include those represented by compounds of Formula (C)

[0068] (C)

[0069] wherein: x is 0 or 1; R 1 is a hydrocarbyl group containing from about 4 to about 18 carbon atoms; R 2is an aliphatic hydrocarbon group containing from about 1 to about 12 carbon atoms; and y is 0 or 1. Such compounds are further discussed in WO 2017 / 205274, published November 30, 2017.

[0070] Industrial applications

[0071] The LMW DPMA can be used in an internal combustion engine. The internal combustion engine can be a 4-stroke engine. The internal combustion engine can or can not have an exhaust gas recirculation system. The internal combustion engine can be fitted with an emission control system or a turbocharger. Examples of emission control systems include diesel particulate filters (DPF), systems employing selective catalytic reduction (SCR).

[0072] In one embodiment, the internal combustion engine can be a diesel fuelled engine, a gasoline fuelled engine, a natural gas fuelled engine, or a hybrid gasoline / alcohol fuelled engine. In one embodiment, the internal combustion engine can be a diesel fuelled engine, and in another embodiment, a gasoline fuelled engine. In one embodiment, the internal combustion engine can be a heavy duty diesel engine. In yet another embodiment, the internal combustion engine can be a gasoline direct injection engine.

[0073] The lubricating composition can have a sulfur content of 1 wt% or less, or 0.8 wt% or less, or 0.5 wt% or less, or 0.3 wt% or less. In one embodiment, the sulfur content can range from 0.001 wt% to 0.5 wt%, or from 0.01 wt% to 0.3 wt%. The phosphorus content can be 0.2 wt% or less, or 0.12 wt% or less, or 0.1 wt% or less, or 0.085 wt% or less, or 0.08 wt% or less, or even 0.06 wt% or less, 0.055 wt% or less, or 0.05 wt% or less. In one embodiment, the phosphorus content can be from 0.04 wt% to 0.12 wt%. In one embodiment, the phosphorus content can be from 100 ppm to 1000 ppm, or from 200 ppm to 600 ppm. The total sulfated ash content can be from 0.3 wt% to 1.2 wt%, or from 0.5 wt% to 1.1 wt% of the lubricating composition. In one embodiment, the sulfated ash content can be from 0.5 wt% to 1.1 wt% of the lubricating composition.

[0074] The lubricating composition can have an SAE viscosity grade of XW-Y, where X can be 0, 5, 10, or 15; and Y can be 8, 12, 16, 20, 30, or 40.

[0075] In one embodiment of the present application, the lubricating composition as described herein has an evaporative percent weight loss (Noack) (as measured by ASTM D5800) of less than 15% or less than 14%, or less than 13%.

[0076] The following examples provide illustrations of the application. These examples are non-exhaustive and are not intended to limit the scope of the application.

[0077] Examples

[0078] PLMA-A: Polylauryl methacrylate (PLMA-A) was synthesized by catalytic chain transfer polymerization. A 1 L round bottom flask was charged with bis[(difluoroboryl)dimethyl phenyl-glyoximato]cobalt(II) (Co(MePh)BF) (21.20 mg) and a stir bar. Nitrogen was bubbled into the flask for 60 minutes. Subsequently, 400 ml of lauryl methacrylate (1.365 mol) previously deoxygenated for 30 minutes was added to the flask through a deoxygenated syringe. The mixture was stirred under a nitrogen atmosphere until the catalyst dissolved. Meanwhile, a solution of dimethyl 2,2'-azobis(2-methyl propionate) (V601, 3.14 g, 0.014 mol, 1 mol% with respect to monomer) and 400 ml of toluene (isovolumic with the monomer) was charged into a 500 mL round bottom flask and purged with nitrogen for 30 minutes. Subsequently, the monomer and catalyst solution were heated under inert atmosphere. When the temperature of the catalyst solution reached 75 °C, the initiator solution was added. The reaction was continued under continuous stirring for 6 hours. The final product was purified by precipitation in methanol, resulting in a viscous colorless liquid. Mn of PMLA-A was 2000; Mw was 3200, and PDI was 1.61.

[0079] PLMA-B: Poly(lauryl methacrylate) (PLMA-B) was synthesized by catalytic chain transfer polymerization. A 1 L round bottom flask was charged with bis[(difluoroboryl)dimethylphenyl-glyoximate] cobalt(II) (Co(MePh)BF) (18.81 mg) and a stir bar. Nitrogen was bubbled into the flask for 60 minutes. Subsequently, 400 ml of lauryl methacrylate (1.365 mol) previously deoxygenated for 30 minutes was added to the flask through a deoxygenated syringe. The mixture was stirred under a nitrogen atmosphere until the catalyst dissolved. Meanwhile, a solution of dimethyl 2,2'-azobis(2-methylpropanoate) (V601, 3.14 g, 0.014 mol, 1 mol% with respect to monomer) and 400 ml of toluene (equal volume to the monomer) was charged into a 500 mL round bottom flask and purged with nitrogen for 30 minutes. Subsequently, the monomer and catalyst solution were heated under inert atmosphere. When the temperature of the catalyst solution reached 75 °C, the initiator solution was added. The reaction was continued for 6 hours under continuous stirring. The final product was purified by precipitation in methanol, resulting in a viscous colorless liquid. PLMA-B has a Mn of 2200; Mw of 4200, and a PDI of 1.91.

[0080] Dispersant preparation method

[0081] Method 1 : Conventional heating using an oil bath - PLMA-B (0.5 g, 0.23 mmol, Mn = 2200 g / mol, PDI = 1.91), hexylamine (90 μΐ, 0.69 mmol, 3 equivalents with respect to the vinyl groups of the macromonomer), 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU, 90 μΐ, 0.60 mmol, 1 / 1 v / v with respect to the amine), and a stir bar were added to a 20 ml vial. The temperature was 40 °C and the duration of the experiment was 24 hours. The final product was purified by precipitation in methanol. Conversion by NMR: 99.9%, yield: 95%.

[0082] Method 2: Microwave reactor - PLMA-B (0.5 g, 0.23 mmol, Mn = 2200 g / mol, PDI = 1.91), hexylamine (90 μΐ, 0.69 mmol, 3 equivalents with respect to the vinyl groups of the macromonomer), 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU, 90 μΐ, 0.60 mmol, 1 / 1 v / v with respect to the amine), and a stir bar were added to a 5 ml microwave reactor vial. The vial was sealed and placed in the microwave reactor. The pressure was set to 4 bar, the temperature was 40 °C, and the duration was 2 hours. The final product was purified by precipitation in methanol. Conversion by NMR: 99.9%, yield: 95%.

[0083] The comparison of reaction time and conversion for Method 2 microwave vs. Method 1 conventional heating is shown in the table below.

[0084]

[0085] Microwave functionalization methods achieved higher conversions in shorter reaction times compared to oil bath promoted polymer functionalization with amines in the presence and absence of solvent.

[0086] Dispersant evaluation

[0087] Dispersants according to the disclosed technology were prepared using Method 2 microwave method to evaluate performance against standard dispersant polymethacrylate.

[0088] Dispersant 1 - Macromonomer PLMA-A (10 g, 5 mmol, Mn = 2000 g / mol, PDI = 1.61), 3-(dimethylamino)-1 -propylamine (6.29 ml, 50 mmol, 10 equivalents relative to vinyl groups of macromonomer), 4 ml of toluene, and a stir bar were added to a 20 ml microwave reactor vial. The vial was sealed and placed in the microwave reactor. The pressure was set to 4 bar, while the temperature was 180 °C, and the duration was 2 hours. The final product was purified by precipitation in methanol. Conversion by NMR: 99.9%, Yield: 94%.

[0089] Dispersant 2 - Macromonomer PLMA-A (10 g, 5 mmol, Mn = 2000 g / mol, PDI = 1.61), 3-morpholinopropylamine (7.30 ml, 50 mmol, 10 equivalents relative to vinyl groups of macromonomer), 4 ml of toluene, and a stir bar were added to a 20 ml microwave reactor vial. The vial was sealed and placed in the microwave reactor. The pressure was set to 4 bar, while the temperature was 180 °C, and the duration was 2 hours. The final product was purified by precipitation in methanol. Conversion by NMR: 99.9%, Yield: 94%.

[0090] Dispersant 3 (comparative) - Initially, 1000 g (0.79 mol) of polyisobutenyl succinic anhydride (polyisobutylene-based substituent with Mn = 1250 g / mol, PDI = 1.2) was added to a 3 L flange flask equipped with an overhead stirrer, a Dean-Stark trap, a nitrogen inlet, and a thermocouple. The flask was heated to 180 °C under a nitrogen atmosphere. Once the temperature was reached, 0.79 mol of 3-aminopropylmorpholine was added to the flask. The reaction was allowed to proceed for 2 hours. The final product was purified by precipitation in methanol. Conversion by NMR: 99.9%, Yield: 94%. A 2 L flange flask, equipped with an overhead stirrer, Dean-Stark trap, nitrogen inlet, and thermocouple, was initially charged with 1000 g (1.07 mol) of polyisobutenyl succinic anhydride (polyisobutylene-based substituent having a number average molecular weight of about 1550) and diluent oil (425.7 g). The nitrogen flow through the vessel was set to 1 cubic foot per hour, and the reaction mixture was heated to 90 °C. Once temperature was reached, 42.2 g (0.29 mol) of TETA was added subaerially over 1 hour. An exotherm was observed, and controlled addition of the amine was performed to maintain the reaction temperature below 120 °C. After the addition was complete, the reaction mixture was heated to 150 °C and stirred at that temperature for an additional 4 hours. As the reaction progressed, water was produced and removed using a Dean-Stark trap. The progress of the reaction was monitored by IR, whereby the formation of cyclic imide and carboxylic acid groups could be observed. The resulting material was cooled to 60 °C and collected to give the product.

[0091] Dispersant 4 (comparative) - A 2 L flange flask, equipped with an overhead stirrer, Dean-Stark trap, nitrogen inlet, and thermocouple, was initially charged with 1000 g (1.07 mol) of polyisobutenyl succinic anhydride (polyisobutylene-based substituent having a number average molecular weight of about 1550) and diluent oil (425.7 g). The nitrogen flow through the vessel was set to 1 cubic foot per hour, and the reaction mixture was heated to 90 °C. Once temperature was reached, 42.2 g (0.29 mol) of TETA was added subaerially over 1 hour. An exotherm was observed, and controlled addition of the amine was performed to maintain the reaction temperature below 120 °C. After the addition was complete, the reaction mixture was heated to 150 °C and stirred at that temperature for an additional 4 hours. As the reaction progressed, water was produced and removed using a Dean-Stark trap. The progress of the reaction was monitored by IR, whereby the formation of cyclic imide and carboxylic acid groups could be observed. The resulting material was cooled to 60 °C and collected to give the product. A 2 L flange flask, equipped with an overhead stirrer, Dean-Stark trap, nitrogen inlet, and thermocouple, was initially charged with 1000 g (1.07 mol) of polyisobutenyl succinic anhydride (polyisobutylene-based substituent having a number average molecular weight of about 1550) and diluent oil (425.7 g). The nitrogen flow through the vessel was set to 1 cubic foot per hour, and the reaction mixture was heated to 90 °C. Once temperature was reached, 42.2 g (0.29 mol) of TETA was added subaerially over 1 hour. An exotherm was observed, and controlled addition of the amine was performed to maintain the reaction temperature below 120 °C. After the addition was complete, the reaction mixture was heated to 150 °C and stirred at that temperature for an additional 4 hours. As the reaction progressed, water was produced and removed using a Dean-Stark trap. The progress of the reaction was monitored by IR, whereby the formation of cyclic imide and carboxylic acid groups could be observed. The resulting material was cooled to 60 °C and collected to give the product.

[0092] Dispersant 5 (comparative) was synthesized by catalytic chain transfer polymerization of polylauryl methacrylate-poly(2-(dimethylamino)ethyl methacrylate) copolymer (PLMA-co-PDMAEMA). A 200 ml round bottom flask was charged with bis[(difluoroboryl)dimethylphenyl-glyoxime] cobalt(II) (Co(MePh)BF) (3 mg) and a stir bar. Nitrogen was bubbled into the flask for 60 minutes. Subsequently, lauryl methacrylate (50 ml, 0.17 mol), dimethylaminoethyl methacrylate (DMAEMA, 5.73 ml, 0.034 mol), and 2,2’-azobis(2-methylpropionamid) dimethyl ester (V601, 471 mg, 1 mol% relative to monomers) previously deoxygenated for 30 minutes were added to the flask by means of a deoxygenated syringe. The mixture was stirred under a nitrogen atmosphere until the catalyst dissolved. Subsequently, the solution was heated under inert atmosphere for 6 hours with continuous stirring. The final product was purified by precipitation in methanol, resulting in a viscous colorless liquid. PLMA-C had a Mn of 2600; a Mw of 4320, and a PDI of 1.66.

[0093] A summary of the structural features of the dispersants is provided in the table below.

[0094] Backbone Backbone Mn Amine Multiple primary N Dispersant 1 PLMA 2000 DMAPA No Dispersant 2 PLMA 2000 APLM No Dispersant 3 (comparative) PIB 1550 TETA Yes Dispersant 4 (comparative) PIB 1000 DMAPA No Dispersant 5 (comparative) PLMA 2600 From N-containing monomer No

[0095] Dispersants 1-5 were mixed into fully formulated lubricating oil according to the description in the table below.

[0096]

[0097] Performance testing was performed on samples 1-6 as described herein. Kinematic viscosity was measured at 100 °C and 40 °C according to ASTM D445. Low temperature viscosity and high temperature viscosity were also recorded for each sample. Low temperature performance was evaluated according to ASTM D5293, while high temperature viscosity performance was evaluated according to ASTM D4683. Oxidation stability was measured according to ASTM D6186. Microcoking test (MCT) was used to evaluate the tendency of the fluid to form deposits when subjected to high temperatures in an air environment. In this test, a sample of oil is placed in a trough of aluminum alloy plates heated at one end (280 °C) and regulated at the other end (230 °C). The trough is set to tilt 1.5 wt% towards the hot end. The duration of the test is 90 minutes. At the end of the test, the plates are rated from 1-10, with 10 being the one with the least amount of deposits and 1 being the one with the most amount of deposits.

[0098] Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 KV at 40°C 31.84 27.98 27.61 25.63 25.34 25.68 KV at 100°C 6.407 5.705 5.748 5.416 5.376 5.448 CCS at -35°C 4020 3740 3360 3090 3070 2990 HTHS at 150°C 2.22 2 2.02 1.92 1.92 1.89 PDSC 98.3 92.9 103.3 103.5 104.3 82.5 MCT index 7.7 6.8 6.9 8.3 7 5.1

[0099] There are various strategies that can be used to reduce the viscosity contribution of the dispersant to the fully formulated fluid. Reduction of the molecular weight of the hydrophobic chain can result in a lower viscosity dispersant. Replacing an amine that is capable of crosslinking with a non-crosslinking amine can also result in a lower viscosity dispersant and fully formulated fluid. Compare the results of Sample 1 to Sample 2, where the fluid dispersant differs due to the just described properties. While the expected viscosity reduction is observed, there is also a reduction in the cleanliness performance of Sample 2 as a fully formulated fluid. Another strategy to reduce the viscosity of the fluid is to simply reduce the processing rate of the dispersant. Compare Sample 3 to Sample 1. Again, the expected viscosity reduction is observed as well as a reduction in the cleanliness performance. Samples 4 and 5 allow for a lower viscosity fluid (compared to Samples 1-3) without sacrificing cleanliness performance. Considering that the processing rate of the dispersant is the same for all fluids, Samples 4 and 5 are most accurate compared to Sample 3.

[0100] Poly(meth)acrylates containing amine monomers are well known. These are typically prepared by free radical polymerization of (meth)acrylate monomers with (meth)acrylic amine monomers. The resulting copolymer contains a mixture of amine containing monomers and ester containing monomers. The amine containing monomers are randomly distributed throughout the polymer. The molecular weight of these traditionally prepared copolymers cannot be controlled to the target Mn of 1500 to 3000 (requiring the use of large amounts of initiator).

[0101] Using the catalyzed chain transfer polymerization process described herein, copolymers of acrylate and amine containing acrylic monomers with a target Mn of 1500 to 3000 are prepared. The resulting copolymer contains randomly distributed amine containing methacrylate monomers (see dispersant 5). This can be compared to the end functionalized dispersants of the present invention described herein. Comparison of the performance results of Sample 6 to Sample 4 and / or 5 shows the importance of end functionalization of the polymer.

[0102] It is known that some of the materials described above can interact in the final formulation, such that the components of the final formulation can be different from the components that were originally added. The products formed thereby, including the products formed upon employing the lubricant composition of the present invention in its intended use, can not be susceptible of easy description. Nevertheless, all such modifications and reaction products are included within the scope of the present invention, which encompasses lubricant compositions prepared by admixing the components described above.

[0103] Each of the documents referred to above is incorporated herein by reference. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about". Unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which can contain the isomers, by-products, derivatives and other such materials which are normally understood to be present in the commercial grade. However, the amount of each chemical component is presented exclusive of any solvent or diluent oil, which can be customarily present in the commercial material. It is to be understood that the upper and lower amount, range, and ratio limits set forth herein can be independently combined. Similarly, the ranges and amounts for each element of the application can be used together with ranges or amounts for any of the other elements.

[0104] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense, which is well understood by those skilled in the art. Specifically, it refers to a group having carbon atoms directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include: hydrocarbon substituents, including aliphatic, alicyclic, and aromatic substituents; substituted hydrocarbon substituents, i.e., substituents containing non-hydrocarbon groups which do not alter the predominantly hydrocarbon nature of the substituent in the context of this application; and heterosubstituents, i.e., substituents which similarly have predominantly hydrocarbon character but contain substituents in the ring or chain which are not carbon. More detailed definitions of the term "hydrocarbyl substituent" or "hydrocarbyl group" are described in paragraphs

[0118] through

[0119] of International Publication WO2008147704, or similar definitions in paragraphs

[0137] through

[0141] of published application US 2010-0197536.

[0105] As used herein, total base number (TBN) of a detergent can be measured by ASTM D2896.

[0106] As used herein, the transitional term "comprising," synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. However, in each instance herein in which "comprising" is recited, the term is intended to also encompass, as alternative embodiments, the phrases "consisting essentially of and "consisting of," where "consisting of excludes any element not specified and "consisting essentially of permits the inclusion of additional unrecited elements of a material or step that do not materially affect the basic or novel characteristic(s) of the claimed composition or method.

[0107] While the application has been described with respect to the preferred embodiments, it will be appreciated that those skilled in the art, on occasion, will be able to devise variations without departing from the spirit of the application. Accordingly, it will be understood that the application disclosed herein is intended to cover all such modifications as fall within the scope of the appended claims.

[0108] A low molecular weight dispersant polymethacrylate polymer ("LMW DPMA") comprising the reaction product of a vinyl-terminated polymethacrylate polymer having a molecular weight of from about 1000 Mn to about 5000 Mn and a nitrogen-containing group.

[0109] The LMW DPMA of the immediately preceding paragraph, wherein the vinyl-terminated polymethacrylate polymer is synthesized by catalytic chain transfer polymerization ("CCTP") of at least one methacrylate monomer with a catalytic amount of a catalytic chain transfer agent.

[0110] The LMW DPMA of any of the preceding paragraphs, wherein the at least one methacrylate monomer comprises a monomer derived from a saturated alcohol.

[0111] The LMW DPMA of any of the preceding paragraphs, wherein the at least one methacrylate monomer comprises methyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises ethyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises propyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises butyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 2-methylpentyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 2-propylheptyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 2-butyloctyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 2-ethylhexyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises octyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises nonyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises isooctyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises isononyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 2-tert-butylheptyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 3-isopropylheptyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises decyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises undecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 5-methylundecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises dodecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 2-methyldodecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises tridecyl methacrylate.The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 5-methyltridecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises myristyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises pentadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises hexadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 2-methylhexadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises heptadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 5-isopropylheptadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 4-tert-butyloctadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 5-ethyloctadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 3-isopropyl octadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises octadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises nonadecyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises eicosyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises a methacrylate derived from an unsaturated alcohol. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises oleyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises cycloalkyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises 3-vinyl-2-butylcyclohexyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises borneol methacrylate.

[0112] The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises an alkyl methacrylate having a long chain alcohol derived group from a long chain fatty alcohol. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 1620. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 10. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 810. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 12. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 1012EE. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 1014CDC. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 1214. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 1214GC. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 1214HA. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 1216. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 125. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 91. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 23. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 25, 45. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 135. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises a C13-C15 alcohol. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises isotridecanol. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 2465. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 2470. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 8655. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 80. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 24. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 26. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 28. The LMW DPMA of any of the preceding sentences, wherein the fatty alcohol comprises 68.

[0113] The LMW DPMA of any of the preceding sentences, wherein the at least one methacrylate monomer comprises an alkyl methacrylate having a group derived from a branched alcohol from a Guerbet alcohol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-butyl octanol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-butyl decanol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-hexyl octanol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-hexyl decanol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-octyl decanol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-hexyl dodecanol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-octyl dodecanol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-decyl tetradecanol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-dodecyl hexadecanol. The LMW DPMA of any of the preceding sentences, wherein the Guerbet alcohol comprises 2-tetradecyl octadecanol.

[0114] The LMW DPMA of any of the preceding sentences, wherein the methacrylate monomer comprises benzyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the methacrylate monomer comprises phenyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the methacrylate monomer comprises phenyl propyl methacrylate. The LMW DPMA of any of the preceding sentences, wherein the methacrylate monomer comprises phenyl styrene methacrylate.

[0115] The LMW DPMA of any of the preceding sentences, wherein the methacrylate monomer comprises an oil insoluble methacrylate monomer that is polymerizable in oil. The LMW DPMA of any of the preceding sentences, wherein the methacrylate monomer comprises a mixture of any of the foregoing monomers.

[0116] The LMW DPMA of any of the preceding sentences, wherein the vinyl terminated polymethacrylate polymer comprises a polymer of Formula 1 :

[0117]

[0118] wherein R1 is an alkyl group having 1 to 24 carbon atoms; and wherein n is an integer from 3 to 30.

[0119] The LMW DPMA of any of the preceding sentences, wherein the LMW DPMA can be represented by the following Formula II:

[0120]

[0121] wherein R1 and n are as described above, and X is a nitrogen containing compound.

[0122] The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aromatic amine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises aniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N-alkylaniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N-methylaniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N-butylaniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises di(p-methylphenyl)amine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises naphthylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 4-aminodiphenylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N,N-dimethylphenylenediamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 4-(4-nitrophenylazo)aniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises sulfamerazine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 4-phenoxyaniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 3-nitroaniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 4-aminoacetanilide. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 4-amino-2-hydroxy-benzoic acid phenyl ester. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N-(4-amino-5-methoxy-2-methyl-phenyl)-benzamide. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N-(4-amino-2,5-dimethoxy-phenyl)-benzamide. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N-(4-amino-2,5-diethoxy-phenyl)-benzamide. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N-(4-amino-phenyl)-benzamide. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 4-phenylazobenzenamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises p-ethoxyaniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises p-dodecylaniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises cyclohexyl-substituted naphthylamine.The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a thiophene-substituted aniline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an amino-substituted aromatic compound.

[0123] The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an amine in which the amine nitrogen is part of an aromatic ring. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 3-aminoquinoline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 5-aminoquinoline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 8-aminoquinoline. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aromatic amine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 2-amino benzimidazole. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N-(4-anilinophenyl)-3-aminobutanamide. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminocarbazole. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminoinode. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminopyrrole. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminoindazolinone. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminopiperidine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a mercaptotriazole. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminophenothiazine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminopyridine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminopyrazine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminopyrimidine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a pyridine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a pyrazine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a pyrimidine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminothiadiazole. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminothiathiadiazole. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an aminobenzotriazole. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 3-amino-N-(4-anilinophenyl)-N-isopropylbutanamide.The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N-(4-anilinophenyl)-3-{(3-aminopropyl)-(cocoalkyl)amino} butyramide. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises an amine of the general structure φ-CONH-φ-NH2, wherein the phenyl groups can be substituted.

[0124] The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a non-aromatic amine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a monoamine having from 1 to 8 carbon atoms. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises methylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises ethylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises propylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises dimethylaminopropylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises dimethylaminopropylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises dibutylaminopropylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises dimethylaminoethylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises diethylaminoethylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises dibutylaminoethylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises l-(2-aminoethyl)piperidine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises l-(2-aminoethyl)pyrrolidine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N,N-dimethylethylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 3-(dimethylamino)-l -propylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises O-(2-aminopropyl)-O'-(2-methoxyethyl)polypropylene glycol. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises N,N-dimethyldipropylene triamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises aminoethylmorpholine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises 3-morpholinopropylamine. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises aminoethyl ethylene urea. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises aminopropylmorpholine.

[0125] The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a mixture of non-aromatic amines. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a mixture of aromatic amines. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises a combination of non-aromatic amines and aromatic amines. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound comprises trace amounts of aromatic amines. The LMW DPMA of any of the preceding sentences, wherein the nitrogen-containing compound is substantially free of or free of aromatic amines.

[0126] A lubricant composition comprising an oil of lubricating viscosity and the LMW DPMA of any of the preceding sentences.

[0127] The lubricating composition of the preceding paragraph, comprising 0.1 wt% to 10 wt% of the LMW DPMA. The lubricating composition of the preceding paragraph, comprising 0.25 wt% to 8 wt% of the LMW DPMA. The lubricating composition of the preceding paragraph, comprising 0.5 wt% to 5 wt% of the LMW DPMA.

[0128] A method of lubricating an internal combustion engine, the method comprising supplying to the internal combustion engine a lubricating composition, including the lubricating composition of the preceding paragraph. Use of the lubricating composition of the preceding paragraph for improving fuel efficiency.

[0129] A method for making a low molecular weight dispersant polymethacrylate polymer ("LMW DPMA") as described in the preceding paragraph, the method comprising: 1) making the vinyl-terminated polymethacrylate polymer by catalytic chain transfer polymerization; and 2) reacting the vinyl-terminated polymethacrylate polymer of the preceding paragraph with a nitrogen-containing group in the presence of microwave radiation. The method of the preceding sentence, wherein the vinyl-terminated polymethacrylate polymer has a molecular weight of about 1000 Mn to about 5000 Mn and a nitrogen-containing group.

Claims

1. A low molecular weight dispersant polymethacrylate polymer ("LMW DPMA") comprising the reaction product of a vinyl-terminated polymethacrylate polymer having a molecular weight of 1000 Mn to 5000 Mn with a nitrogen-containing group, wherein the low molecular weight dispersant polymethacrylate polymer is represented by Formula II below wherein R1 is an alkyl group having 1 to 24 carbon atoms; X is a nitrogen-containing group; and n is an integer from 3 to 30.

2. The low molecular weight dispersant polymethacrylate polymer of claim 1, wherein the nitrogen-containing group comprises 3-morpholinopropylamine.

3. The low molecular weight dispersant polymethacrylate polymer of claim 1, wherein the nitrogen-containing group comprises 3-(dimethylamino)-l -propylamine.

4. A lubricant composition comprising an oil of lubricating viscosity and the low molecular weight dispersant polymethacrylate polymer as recited in claim 1.

5. A method of lubricating an internal combustion engine, the method comprising supplying to the internal combustion engine a lubricant composition, including the lubricant composition of claim 4.

6. Use of the lubricant composition of claim 4 to improve fuel efficiency.

7. A process for preparing a low molecular weight dispersant polymethacrylate polymer, the process comprising: 1) preparing a vinyl-terminated polymethacrylate polymer by catalytic chain transfer polymerization; 2) reacting the vinyl-terminated polymethacrylate polymer with a nitrogen-containing group in the presence of microwave radiation.

8. The method of claim 7, wherein the vinyl-terminated polymethacrylate polymer has a molecular weight of 1000 Mn to 5000 Mn and is reacted with a nitrogen-containing group.

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