JP2020517787A - Lubricating composition - Google Patents

Abstract

Use of a nitrogen-containing ashless dispersant in a lubricating composition for reducing wear in the presence of ZDTP and soot, the nitrogen-containing ashless dispersant having a functionality (F) of greater than 1.4. ..

Description

The present invention relates to lubricating oil compositions, particularly lubricating oil compositions suitable for lubricating internal combustion engines and having reduced wear characteristics.

Increasingly stringent automotive regulations regarding exhaust gas and fuel efficiency are increasing the demand for both engine manufacturers and lubricant formulators to provide effective solutions to improve fuel economy.

Optimizing lubricants using high performance basestocks and new additives is a flexible solution to increasing challenges.

Antiwear additives are important for alleviating the problems that result from using low viscosity formulations to reduce fuel consumption, and such various additives are already known in the art. Has been.

式中、Ｒ^２〜Ｒ^５は同じでも異なっていてもよく、各々、１〜２０個の炭素原子、好ましくは３〜１２個の炭素原子を含有する第一級アルキル基、３〜２０個、好ましくは３〜１２個の炭素原子を含有する第二級アルキル基、アリール基、またはアルキル基で置換されたアリール基であり、当該アルキル置換基は１〜２０個の炭素原子、好ましくは３〜１８個の炭素原子を含有する。 Common antiwear additives well known for use in lubricating compositions are zinc dithiophosphates, such as zinc dialkyl-, diaryl-, or alkylaryl-dithiophosphates. Zinc dithiophosphate can be conveniently represented by the general formula II:

In the formula, R ^{2 to} R ⁵ may be the same or different and each is a primary alkyl group containing 1 to 20 carbon atoms, preferably 3 to 12 carbon atoms, 3 to 20, It is preferably a secondary alkyl group containing 3 to 12 carbon atoms, an aryl group or an aryl group substituted with an alkyl group, said alkyl substituent being 1 to 20 carbon atoms, preferably 3 to It contains 18 carbon atoms.

Examples of suitable commercially available zinc dithiophosphates include zinc dithiophosphates available from Lubrizol Corporation under the trade names "Lz1097" and "Lz1395", and trade names "OLOA267" and "OLOA269R" available from Chevron Oronite. Zinc dithiophosphate, as well as zinc dithiophosphate available from Afton Chemical under the trade name "HITEC 7197"; C9417, zinc dithiophosphate, trade name Infineum C9417, zinc dithiophosphate available from Infineum, trade names "Lz677A", "Lz1095". , And zinc dithiophosphate available from Lubrizol Corporation under “Lz1371”, zinc dithiophosphate available from Chevron Oronite under the tradename “OLOA262”, and zinc dithiophosphate available from Afton Chemical under the tradename “HITEC7169”; and Zinc dithiophosphates, zinc dithiophosphates available from Lubrizol Corporation under the trade names "Lz1370" and "Lz1373", and zinc dithiophosphates available from Chevron Oronite under the trade name "OLOA260".

Zinc dithiophosphate compounds are useful for reducing wear in lubricating compositions, but in the presence of soot, zinc dithiophosphate can lead to undesired increase in wear via a newly identified wear mechanism Recently, I found out that The corrosion/abrasion wear mechanism was identified and published in 2010. Olomolehin, Y. , Kapadia, R.; G. , Spikes, H.; A. , "Antagonistic interaction of antiwear additive and carbon black." Trib Letters 37, 49-58, (2009). More recent papers have recently reaffirmed this mechanism. Salehi, F.; Motamen, D.M. N. Khaemba, A.; Morina, and A.M. See Nillele, "Corrosive-Abrasive Wear Induced by Soot in Boundary Lubrication Regime." Trib Letters 63, 1-11, (2016).

Therefore, it is desirable to find a way to reduce the wear of lubricating compositions containing a zinc dithiophosphate compound in the presence of soot.

Surprisingly, it has now been discovered that the use of certain nitrogen-containing ashless dispersants can provide lubricating oil compositions that exhibit reduced wear in the presence of zinc dithiophosphate compounds and soot.

Accordingly, the present invention provides for the use of a nitrogen-containing ashless dispersant in a lubricating composition for reducing wear in the presence of a zinc dithiophosphate compound and soot, the nitrogen-containing ashless dispersant being less than 1.4. Have a functionality (F) that exceeds

As used herein, the term "soot" refers to a dark black, powdery or flaky material consisting primarily of amorphous carbon. Gas soot contains polycyclic aromatic hydrocarbons (PAH). Soot is generated by incomplete combustion of organic matter such as hydrocarbon fuel. It consists of agglomerated nanoparticles with a diameter of 6-30 nm. The soot particles can be mixed with metal oxides and minerals and can be coated with sulfuric acid. In the context of internal combustion engines, soot can migrate from the combustion chamber to the lubricant and accumulate in the lubricant.

In the context of the present invention, the amount of soot in a lubricating composition containing a zinc dithiophosphate compound is typically at a level of 0.1% to 10% by weight. In one embodiment, the soot level is 2-7% by weight of the lubricating composition. In another embodiment, the soot level is 3.5-7% by weight of the lubricating composition. In another embodiment, the soot level is 5-6% by weight of the lubricating composition.

The nitrogen-containing ashless dispersant is present in the lubricating composition herein in an amount of 0.001% to 0.15% by weight, preferably 0.05% to 0.1% by weight, based on the weight of the lubricating composition. It is present at a level that provides a% nitrogen level.

Nitrogen-containing ashless dispersants are used herein to reduce the wear exhibited by lubricating compositions in the presence of zinc dithiophosphate compounds and soot. Thus, the term "reduce wear" as used herein refers to lubricating compositions containing zinc dithiophosphate and soot, but not containing the nitrogen-containing ashless dispersant described herein. This means reducing the wear level to below the level.

In a preferred embodiment herein, a nitrogen-containing ashless dispersant is used to provide wear, a similar lubricating composition containing zinc dithiophosphate and soot, but not the nitrogen-containing ashless dispersant described herein. Compared to the wear of the article, it reduces wear by at least 5%, more preferably by at least 10%, even more preferably by at least 50%, in particular by at least 80%, even more in particular by at least 90%.

Suitable dispersants for use in the present invention include an oil-soluble polymer long chain backbone having functional groups that can associate with the particles to be dispersed. Typically, such dispersants have amine, amine alcohol, or amide polar moieties attached to the polymer backbone, often through cross-linking groups. Dispersants are, for example, oil-soluble salts, esters, aminoesters, amides, imides, and oxazolines of long-chain hydrocarbon-substituted mono- and polycarboxylic acids or their anhydrides; thiocarboxylate derivatives of long-chain hydrocarbons; Long chain aliphatic hydrocarbons having directly attached polyamine moieties; and Mannich condensation products formed by condensing long chain substituted phenols with formaldehyde and polyalkylene polyamines.

Generally, each mono- or dicarboxylic acid-forming moiety reacts with a nucleophilic group (amine or amide) and the number of functional groups on the polyalkenyl-substituted carboxylic acylating agent determines the number of nucleophilic groups on the finished dispersant. To do.

Description of PIB The polyalkenyl moiety of the dispersant used in the present invention is from about 700 to about 3000, preferably 950 to 3000, such as 950 to 2800, more preferably about 950 to 2500, and most preferably about 950 to about 950. It has a number average molecular weight of 2400. The molecular weight of the dispersant is generally represented by the molecular weight of the polyalkenyl moiety. It is because the exact molecular weight range of the dispersant depends on a number of parameters including the type of polymer used to derive the dispersant, the number of functional groups, and the type of nucleophilic group used. is there.

The polyalkenyl moiety from which the high molecular weight dispersant is derived is preferably defined by the ratio of the weight average molecular weight (M _w ) to the number average molecular weight (M _n ) and is also referred to as polydispersity, a narrow molecular weight distribution (MWD). ) Has. Specifically, the dispersant-derived polymer used in the present invention is from about 1.5 to about 2.0, preferably from about 1.5 to about 1.9, and most preferably from about 1.6 to. It has a M _w /M _n of about 1.8.

Suitable hydrocarbons or polymers used in forming the dispersants used in the present invention include homopolymers, interpolymers, or low molecular weight hydrocarbons. One family of such polymers, at least one _C 3 _{-C 28} alpha having an ethylene and / or formula _H 2 C = CHR ¹ - comprises a polymer of an olefin, wherein, ^{R 1} is 1 to 26 pieces A straight or branched chain alkyl radical containing up to 8 carbon atoms, the polymer containing carbon-carbon unsaturation, preferably a high degree of terminal ethenylidene unsaturation. Preferably, such a polymer comprises an interpolymer of ethylene and at least one alpha-olefin of the above formula, wherein R ¹ is alkyl of 1 to 18 carbon atoms, more preferably 1 Is alkyl of 8 carbon atoms, and even more preferably alkyl of 1 to 2 carbon atoms. Thus, useful alpha-olefin monomers and comonomers include, for example, propylene, butene-1, hexene-1, octene-1,4-methylpentene-1, decene-1, dodecene-1, tridecene-1, tetradecene-. 1, pentadecene-1, hexadecene-1, heptadecene-1, octadecene-1, nonadecene-1, and mixtures thereof (for example, a mixture of propylene and butene-1). Examples of such polymers are propylene homopolymers, butene-1 homopolymers, ethylene-propylene copolymers, ethylene-butene-1 copolymers, propylene-butene copolymers, etc., which polymers have at least some terminal and/or internal deficiency. Contains saturation. Preferred polymers are unsaturated copolymers of ethylene and propylene and ethylene and butene-1. Interpolymers used herein may contain a comonomer a small amount of, for example, of 0.5 to 5 mol% C ₄ -C ₁₈ non-conjugated diolefin. However, it is preferred that the polymers used in the present invention include only alpha-olefin homopolymers, interpolymers of alpha-olefin comonomers, and interpolymers of ethylene and alpha-olefin comonomers. The molar ethylene content of the polymers used in the present invention is preferably in the range of 0-80%, more preferably 0-60%. When propylene and/or butene-1 is used as comonomer(s) with ethylene, the ethylene content of such copolymers is most preferably from 15 to 50%, but with higher or lower ethylene content. It may be the amount.

These polymers include alpha-olefin monomers, or mixtures of alpha-olefin monomers, or at least ethylene and at least ethylene, in the presence of a catalyst system comprising at least one metallocene (eg, cyclopentadienyl-transition metal compound) and alumoxane compound. one C ₃ -C ₂₈ alpha - by polymerizing a mixture comprising olefin monomer, can be prepared. This process can be used to provide polymers in which 95% or more of the polymer chains have terminal ethenylidene type unsaturation. The percentage of polymer chains exhibiting terminal ethenylidene unsaturation can be determined by FTIR spectroscopy, titration, or C ¹³ NMR. This latter type of interpolymer can be characterized by the formula POLY-C(R ¹ )═CH ₂ , where R ¹ is C ₁ -C ₂₆ alkyl, preferably C ₁ -C ₁₈ alkyl. , More preferably C ₁ -C ₈ , most preferably C ₁ -C ₂ alkyl (eg methyl or ethyl), where POLY represents the polymer chain. The chain length of the R ¹ alkyl group depends on the comonomer(s) selected for use in the polymerization. A minor amount of polymer chains may contain terminal ethenyls, ie vinyls, unsaturated, ie POLY-CH═CH ₂ , part of the polymer being internal monounsaturated, eg POLY-CH═CH(R ¹ ). Can be included, where R ¹ is as defined above. These terminally unsaturated interpolymers can be prepared by known metallocene chemistry and are also described in US Pat. Nos. 5,498,809, 5,663,130, 5,705,577, It can also be prepared as described in U.S. Pat. Nos. 5,814,715, 6,022,929, and 6,030,930.

Another useful class of polymers are those polymers prepared by cationic polymerization of isobutene, styrene and the like. Typical polymers from this class include butene content of about 35 to about 75 wt% and isobutene of about 30 to about 60 wt% in the presence of a Lewis acid catalyst such as aluminum trichloride or boron trifluoride. Mention may be made of polyisobutene obtained by C ₄ refinery-stream polymerization having a content. A preferred source of monomers for making poly-n-butene is a petroleum feed stream such as Raffinate II. These feedstocks are disclosed in the technical field such as US Pat. No. 4,952,739. Polyisobutylene is the most preferred scaffold herein because it is readily available by cationic polymerization from butene streams (eg, using AlCl ₃ or BF ₃ catalysts). Such polyisobutylenes generally contain residual unsaturation in an amount of about 1 ethylenic double bond per polymer chain arranged along the chain. A preferred embodiment utilizes polyisobutylene prepared from a pure isobutylene stream or a Raffinate I stream to prepare a reactive isobutylene polymer having a terminal vinylidene olefin. Preferably, these polymers referred to as highly reactive polyisobutylene (HR-PIB) have a terminal vinylidene content of at least 65%, for example 70%, more preferably at least 80% and most preferably at least 85%. .. The preparation of such polymers is described, for example, in US Pat. No. 4,152,499. HR-PIB is known and is commercially available under the trade names Glissopal™ (from BASF) and Ultravis™ (from BP-Amoco).

The polyisobutylene polymers that can be used are generally based on about 700 to 3000 hydrocarbon chains. Methods for making polyisobutylene are known. Polyisobutylene can be functionalized by halogenation (eg, chlorination), thermal “ene” reaction, or by free radical grafting using a catalyst (eg, peroxide).

The hydrocarbon or polymer backbone may be selected, for example, at any of the carbon-carbon unsaturation sites on the polymer or hydrocarbon chain using any of the above three processes or combinations thereof in any order, or It can be functionalized randomly with a carboxylic acid generating moiety (preferably an acid or anhydride moiety) along the chain.

Processes for reacting polymeric hydrocarbons with unsaturated carboxylic acids, anhydrides, or esters, and the preparation of derivatives from such compounds are described in US Pat. Nos. 3,087,936, 3,172,892. No. 3, No. 3,215,707, No. 3,231,587, No. 3,272,746, No. 3,275,554, No. 3,381,022, No. 3 No. 442,808, No. 3,565,804, No. 3,912,764, No. 4,110,349, No. 4,234,435, No. 5,777,025. No. 5,891,953, and EP 0 382 450 B1, CA-1,335,895, and GB-A-1,440,219.

Polymers or hydrocarbons are predominantly carbon-carbon unsaturated (ethylenically unsaturated) on the polymer or hydrocarbon chain using, for example, halogen-assisted functionalization (eg, chlorination, etc.) processes or thermal “ene” reactions. (Also referred to as olefinic unsaturation), by reacting the polymer or hydrocarbon under conditions that result in the addition of a functional moiety or agent, ie, acid, anhydride, ester moiety, etc. The hydrogen can be functionalized with a carboxylic acid generating moiety, preferably an acid or anhydride.

Functionalization Selective functionalization involves chlorine or bromine in the polymer at a temperature of 60-250°C, preferably 110-160°C, such as 120-140°C, for about 0.5-10 hours, preferably 1-7 hours. The unsaturated α-olefin polymer by halogenation, for example chlorination or bromination, with about 1 to 8% by weight, preferably 3 to 7% by weight of chlorine or bromine, based on the weight of the polymer or hydrocarbons. Can be achieved by: Then, a halogenated polymer or hydrocarbon (hereinafter, skeleton) is added to a sufficient amount of monounsaturated reactant capable of adding a necessary number of functional moieties to the skeleton, for example, a monounsaturated carboxylic acid reactant and 100 to 250. The reaction is carried out at 0°C, usually about 180°C to 235°C for about 0.5 to 10 hours, for example 3 to 8 hours. The resulting product contains the desired number of moles of monounsaturated carboxylic acid reactant per mole of halogenated backbone. Alternatively, the framework and the monounsaturated carboxylic reactant are mixed and heated while adding chlorine to the hot material.

Chlorination usually helps to increase the reactivity of the starting olefin polymer with the monounsaturated functionalized reactants, but is particularly high for some of the polymers or hydrocarbons contemplated for use in the present invention. Not necessary for those preferred polymers or hydrocarbons that have end-link content and reactivity. Therefore, it is preferred to contact the backbone with a monounsaturated functional reactant, such as a carboxylic acid reactant, at an elevated temperature to initiate the initial thermal "ene" reaction. Each reaction is known.

The hydrocarbon or polymer backbone can be functionalized by randomly attaching functional groups along the polymer chain by a variety of methods. For example, the solution or solid form of the polymer may be grafted with a monounsaturated carboxylic acid reactant as described above in the presence of a free radical initiator. When performed in solution, the grafting occurs at elevated temperatures in the range of about 100-260°C, preferably 120-240°C. Preferably, free radical initiated grafting should be accomplished with a mineral lubricating oil solution containing, for example, 1 to 50 wt% polymer, preferably 5 to 30 wt% polymer, based on the initial total oil solution.

Free radical initiators that can be used are peroxides, hydroperoxides, and azo compounds, which preferably have boiling points above about 100° C. and which pyrolyze within the grafting temperature range to provide free radicals. is there. Representative examples of these free radical initiators are azobutyronitrile, 2,5-dimethylhex-3-ene-2, 5-bis-tertiary butyl peroxide and dicumene peroxide. The initiator, when used, is typically used in an amount of 0.005% to 1% by weight based on the weight of the reaction mixture solution. Typically, the monounsaturated carboxylic reactant material and free radical initiator are used in a weight ratio range of about 1.0:1 to 30:1, preferably 3:1 to 6:1. Grafting is preferably carried out in an inert atmosphere such as under a nitrogen blanket. The resulting grafted polymer is characterized by having carboxylic acid (or ester or anhydride) moieties randomly attached along the polymer chain. The free radical grafts described above can be used for other polymers and hydrocarbons used in the present invention.

Preferred monounsaturated reactants used to functionalize the backbone, mono- and dicarboxylic acids material, i.e., acid materials, anhydride material or ester materials include, for example, (i) monounsaturated C ₄ -C ₁₀ dicarboxylic acids, wherein (a) the carboxyl group is vicinyl (ie located on adjacent carbon atoms), and (b) at least one, and preferably both, of said adjacent carbon atoms are said monounsaturated. which is part of, monounsaturated _C 4 _{-C 10} dicarboxylic acids; (ii) derivatives of (i), such as anhydrides of (i) or _C 1 -C ₅ alcohol derived mono - or diesters; (iii) carbon - carbon double bond, a carboxyl group, i.e., monounsaturated _C 3 _{-C 10} monocarboxylic acids are structurally -C = C-CO- and conjugate; derivative (iv) (iii), for example (iii ) Mono- or diester-derived C ₁ -C ₅ alcohols. Mixtures of monounsaturated carboxylic acid materials (i) to (iv) can also be used. The reaction with the skeleton saturates the monounsaturation of the monounsaturated carboxylic acid reactant. Thus, for example, maleic anhydride becomes a backbone-substituted succinic anhydride and acrylic acid becomes a backbone-substituted propionic acid. Examples of such monounsaturated carboxylic acid reactants are fumaric acid, itaconic acid, maleic acid, maleic anhydride, chloromaleic acid, chloromaleic anhydride, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, and Lower alkyl (eg C ₁ -C ₄ alkyl) acid esters of the foregoing, such as methyl maleate, ethyl fumarate, and methyl fumarate.

To provide the required functionality, the monounsaturated carboxylic reactant, preferably maleic anhydride, is typically in an approximately equimolar amount to about 100% by weight excess, based on the moles of polymer or hydrocarbon. , Preferably in amounts ranging from 5 to 50% by weight. Unreacted excess monounsaturated carboxylic acid reactant can be removed from the final dispersant product, if necessary, for example by stripping, usually under vacuum.

Derivatization The functionalized oil-soluble polymeric hydrocarbon backbone is then derivatized with a nitrogen-containing nucleophile, such as amines, amino alcohols, amides, or mixtures thereof to form the corresponding derivatives. Amine compounds are preferred. Amine compounds useful for derivatizing functionalized polymers include at least one amine, and can include one or more additional amines or other reactive or polar groups. These amines may be hydrocarbyl amines or may be predominantly hydrocarbyl amines in which the hydrocarbyl group contains other groups such as hydroxy, alkoxy, amide, nitrile, imidazoline and the like. Particularly useful amine compounds include monoamines and polyamines, eg, about 1-12, such as 3-12, preferably 3-9, and most preferably about 6 to about 7, molecules per molecule. Mention may be made of polyalkenes and polyoxyalkylene polyamines having 2 to 60, for example 2 to 40 (eg 3 to 20) total carbon atoms having a nitrogen atom. Mixtures of amine compounds, prepared for example by reaction of alkylene dihalides with ammonia, can be conveniently used. Preferred amines are, for example, 1,2-diaminoethane, 1,3-diaminopropane; 1,4-diaminobutane; polyethyleneamines such as 1,6-diaminohexane; diethylenetriamine; triethylenetetramine; tetraethylenepentamine; and Aliphatic saturated amines, including polypropyleneamines such as 1,2-propylenediamine; and di-(1,2-propylene)triamine. Such a polyamine mixture is known as PAM and is commercially available. A particularly preferred polyamine mixture is a mixture derived by distilling the light ends from the PAM product. The resulting mixture, known as "heavy" PAM, or HPAM, is also commercially available. Properties and attributes of both PAM and/or HPAM are described, for example, in US Pat. Nos. 4,938,881, 4,927,551, 5,230,714, 5,241,003. No. 5,565,128, No. 5,756,431, No. 5,792,730, and No. 5,854,186.

Other useful amine compounds include cycloaliphatic diamines such as 1,4-di(aminomethyl)cyclohexane and heterocyclic nitrogen compounds such as imidazoline. Another useful class of amines is disclosed in US Pat. Nos. 4,857,217, 4,956,107, 4,963,275, and 5,229,022. Polyamide and related amidoamines. Tris(hydroxymethyl)aminomethane (TAM) described in US Pat. Nos. 4,102,798, 4,113,639, 4,116,876, and UK989,409 is used. You can also Dendrimers, star amines, comb-structured amines can also be used. Similarly, fused amines can be used, as described in US Pat. No. 5,053,152. The functionalized polymer is treated with an amine compound using conventional techniques described in, for example, US Pat. Nos. 4,234,435 and 5,229,022, and EP-A-208,560. React.

Preferred Dispersants Preferred dispersants for use in the present invention are those that include at least one polyalkenyl succinimide, which is a polyalkenyl substituted succinic anhydride (eg, PIBSA) and from about 0.65 to about 1. 25, preferably about 0.8 to about 1.1, and most preferably a reaction product with a polyamine (PAM) having a coupling ratio of about 0.9 to about 1. In the context of this disclosure, "coupling ratio" can be defined as the ratio of the number of succinyl groups in PIBSA to the number of primary amine groups in the polyamine reactant.

Another class of high molecular weight ashless dispersants comprises Mannich base condensation products. Generally, these products contain about 1 mole of long chain alkyl-substituted mono- or polyhydroxybenzene, as disclosed, for example, in U.S. Pat. No. 3,442,808, to about 1-2.5 moles. It is prepared by condensing with a carbonyl compound(s) (eg formaldehyde and paraformaldehyde) and about 0.5-2 moles of a polyalkylene polyamine. Such Mannich base condensation products can include polymer products of metallocene-catalyzed polymerization as a substituent on the benzene group, or similar to those described in US Pat. No. 3,442,808. Can be reacted with a compound containing such a polymer substituted with succinic anhydride. Examples of functionalized and/or derivatized olefin polymers synthesized using metallocene catalyst systems are described in the publications identified above.

Preferred dispersants for use in the present invention are greater than 1.4, more preferably greater than 1.5, for example about 1.5 to about 2.2, more preferably about 1.5 to about 2. It has a functionality (F) of 0, or about 1.5 to about 1.9. The functionality (F) can be determined according to the formula:
F=(SAP x M _n )/((1122 x AI)-(SAP x MW))(1)
Where SAP is the saponification number (ie, the number of milligrams of KOH consumed for complete neutralization of the acid groups of 1 gram of succinic acid-containing reaction product, determined according to ASTM D94) and M _n is the starting The number average molecular weight of the olefin polymer (polybutene), I. Is the percentage of active components of the succinic acid-containing reaction product (the rest is unreacted polybutene and diluent) and MW is the molecular weight of the dicarboxylic acid-forming moiety (98 for maleic anhydride). Generally, each dicarboxylic acid producing moiety (succinic acid group) reacts with a nucleophilic group (polyamine moiety) and the number of succinic acid groups in the PIBSA determines the number of nucleophilic groups in the finished dispersant.

The molecular weight of a polymer, specifically M _n , can be determined by various known techniques. One convenient method is gel permeation chromatography (GPC), which further provides molecular weight distribution information (WW Yau, JJ Kirkland and DD Bly, "Modern Size Excitation Liquid Chromatography"). , John Wiley and Sons, New York, 1979). Another useful method for determining molecular weight, especially for low molecular weight polymers, is vapor pressure osmometry (see, eg, ASTM D3592).

Suitable hydrocarbons or polymers used to form the dispersant include polymers prepared by cationic polymerization of isobutene. Typical polymers in this class include butene content of about 35 to about 75 wt% and isobutene content of about 30 to about 60 wt% in the presence of a Lewis acid catalyst such as boron trifluoride (BF ₃ ). % Polyisobutene obtained by polymerization of a C ₄ purified stream. Preferably, polyisobutylene is prepared from a pure isobutylene stream or a Raffinate I stream to prepare a reactive isobutylene polymer having a terminal vinylidene olefin. Preferably, these polymers referred to as highly reactive polyisobutylene (HR-PIB) have a terminal vinylidene content of at least 60%, for example 70%, more preferably at least 80% and most preferably at least 85%. .. The preparation of such polymers is described, for example, in US Pat. No. 4,152,499. Such a polymer is conventionally referred to as HR-PIB, which is commercially available from Texas Petrochemical Corporation (TPC) or from BASF (under the trade name Glissopal™). Processes in which HR-PIB is heated to react with unsaturated carboxylic acids or anhydrides and the resulting acylating agent (PIBSA) is further reacted with amines are well known and are described, for example, in US Pat. No. 4,152,499. And EP 0 355 895.

To provide the required functionality, the monounsaturated carboxylic acid reactant, (maleic anhydride), is typically about 5 to about 300% excess, preferably about 10%, based on the moles of polymer. It is used in an amount in the range of 200%, for example 20-100% excess. Unreacted excess monounsaturated carboxylic acid reactant can be removed from the final dispersant product if necessary, for example by stripping under vacuum.

Polyamines useful in forming the dispersants include those having or averaging from 3 to 8 nitrogen atoms per molecule, preferably from about 5 to about 8 nitrogen atoms per molecule. .. These amines may be hydrocarbyl amines or may be predominantly hydrocarbyl amines in which the hydrocarbyl group contains other groups such as hydroxy, alkoxy, amide, nitrile, imidazoline and the like. Mixtures of amine compounds, prepared for example by reaction of alkylene dihalides with ammonia, can be conveniently used. Preferred amines are saturated aliphatic amines including, for example, polyethyleneamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and polypropyleneamines such as di-(1,2-propylene)triamine. Such a polyamine mixture is known as PAM and is commercially available. Useful polyamine mixtures include those derived by distilling the light ends from the PAM product. The resulting mixture, known as "heavy" PAM, or HPAM, is also commercially available. Properties and attributes of both PAM and/or HPAM are described, for example, in US Pat. Nos. 4,938,881, 4,927,551, 5,230,714, 5,241,003. No. 5,565,128, No. 5,756,431, No. 5,792,730, and No. 5,854,186.

The total amount of base oil incorporated into the lubricating oil composition of the present invention is preferably in the range of 60-92% by weight, more preferably in the range of 75-90% by weight, based on the total weight of the lubricating oil composition. Amounts, most preferably in the range 75-88% by weight.

There is no particular limitation on the base oil used in the present invention, and various conventionally known mineral oils and synthetic oils can be conveniently used.

The base oil used in the present invention may conveniently comprise a mixture of one or more mineral oils and/or one or more synthetic oils.

Mineral oils include liquid petroleum and solvent-treated or acid-treated paraffin, naphthene, or mixed paraffin/naphthene mineral lubricating oils that can be further refined by hydrofinishing processes and/or dewaxing.

The naphthenic base oil has a low viscosity index (VI) (usually 40 to 80) and a low pour point. Such base oils are produced from feedstocks that are rich in naphthenes and low in wax content and are primarily for lubricants where color and color stability are important and VI and oxidative stability are secondarily important. Used for.

Paraffinic base oils have high VI (generally >95) and high pour points. The base oil is made from paraffin-rich feedstock and is used for lubricants where VI and oxidative stability are important.

Fischer-Tropsch derived base oils can be conveniently used as base oils in the lubricating oil compositions of the present invention, for example Fischer-Tropsch derived base oils are described in EP-A-776959, EP-A-668342, WO -A-97/21788, WO-00/15736, WO-00/14188, WO-00/14187, WO-00/14183, WO-00/14179, WO-00/08115, WO-99/41332, EP -1029029, WO-01/18156, and WO-01/57166.

The synthetic process allows one to construct molecules from simpler materials or to modify the structure to confer the exact properties required.

Synthetic oils include hydrocarbon oils such as olefin oligomers (PAOs), dibasic acid esters, polyol esters, and dewaxed waxy raffinates. The synthetic hydrocarbon base oil sold under the name "XHVI"™ by Royal Dutch/Shell Group of Companies may be conveniently used.

Preferably, the base oil comprises mineral and/or synthetic oils containing greater than 80% by weight, preferably greater than 90% by weight saturates, as measured according to ASTM D2007.

More preferably the base oil contains less than 1.0% by weight, preferably less than 0.1% by weight of sulfur, calculated as elemental sulfur and measured according to ASTM D2622, ASTM D4294, ASTM D4927 or ASTM D3120. ..

Preferably, the viscosity index of the base oil fluid is greater than 80, more preferably greater than 120, measured according to ASTM D2270.

Preferably, the lubricating oil composition is in the range of 2~80mm ² / s at 100 ° C., more preferably in the range of 3~70mm ² / s, and most preferably have a kinematic viscosity in the range of 4~50mm ² / s.

The total amount of phosphorus in the lubricating oil composition of the present invention is preferably in the range of 0.04 to 0.12% by weight, more preferably 0.04 to 0.09% by weight, based on the total weight of the lubricating oil composition. Is the most preferable range, and the most preferable range is 0.045 to 0.08% by weight.

The lubricating oil composition of the present invention is preferably 2.0% by weight or less, more preferably 1.0% by weight or less, most preferably 0.8% by weight or less, based on the total weight of the lubricating oil composition. Has a ash content.

The lubricating oil composition of the present invention preferably has 1.2 wt% or less, more preferably 0.8 wt% or less, most preferably 0.2 wt% or less sulfur, based on the total weight of the lubricating oil composition. Has a content.

The lubricating oil composition of the present invention comprises an antioxidant, an antiwear additive, a detergent, a dispersant, a friction modifier, a viscosity index improver, a pour point depressant, a corrosion inhibitor, an antifoaming agent, and a seal fixing agent. Additional additives such as agents or seal compatibilities can be further included.

Advantageously used antioxidants include those selected from the group of amine antioxidants and/or phenolic antioxidants.

In a preferred embodiment, the antioxidant is present in an amount ranging from 0.1 to 5.0% by weight, more preferably 0.3 to 3.0% by weight, based on the total weight of the lubricating oil composition. It is present in an amount in the range, most preferably in the range 0.5 to 1.5% by weight.

Examples of amine antioxidants that can be conveniently used include alkylated diphenylamines, phenyl-α-naphthylamines, phenyl-β-naphthylamines, and alkylated α-naphthylamines.

Preferred amine-based antioxidants include dialkyldiphenylamines such as p,p'-dioctyl-diphenylamine, p,p'-di-α-methylbenzyl-diphenylamine, and Np-butylphenyl-Np'-octyl. Phenylamine, monoalkyldiphenylamines such as mono-t-butyldiphenylamine, and mono-octyldiphenylamines, bis(dialkylphenyl)amines such as di-(2,4-diethylphenyl)amine, and di(2-ethyl-4-). Nonylphenyl)amine, alkylphenyl-1-naphthylamine, such as octylphenyl-1-naphthylamine, n-t-dodecylphenyl-1-naphthylamine, 1-naphthylamine, arylnaphthylamine, such as phenyl-1-naphthylamine, phenyl-2-naphthylamine. , N-hexylphenyl-2-naphthylamine, and N-octylphenyl-2-naphthylamine, phenylenediamines such as N,N'-diisopropyl-p-phenylenediamine, and N,N'-diphenyl-p-phenylenediamine, and Mention may be made of phenothiazines such as phenothiazine and 3,7-dioctylphenothiazine.

Preferred amine-based antioxidants include the following trade names: “Sonoflex OD-3” (from Seiko Kagaku Co.), “Irganox L-57” (from Ciba Specialty Chemicals Co.), and phenothiazine (Hodokauga. From) are commercially available.

Examples of phenolic antioxidants that can be conveniently used include C7-C9 branched alkyl esters of 3,5-bis(1,1-dimethyl-ethyl)-4-hydroxy-benzenepropanoic acid, 2-t. -Butylphenol, 2-t-butyl-4-methylphenol, 2-t-butyl-5-methylphenol, 2,4-di-t-butylphenol, 2,4-dimethyl-6-t-butylphenol, 2-t -Butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-4-alkylphenol, for example 2,6-di -T-butylphenol, 2,6-di-t-butyl-4-methylphenol and 2,6-di-t-butyl-4-ethylphenol, 2,6-di-t-butyl-4-alkoxyphenol, For example, 2,6-di-t-butyl-4-methoxyphenol and 2,6-di-t-butyl-4-ethoxyphenol, 3,5-di-t-butyl-4-hydroxybenzylmercaptooctyl acetate, alkyl -3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, for example n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, n-butyl- 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and 2'-ethylhexyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,6-dt -Butyl-α-dimethylamino-p-cresol, 2,2'-methylene-bis(4-alkyl-6-t-butylphenol), for example 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2-methylenebis(4-ethyl-6-t-butylphenol), bisphenol such as 4,4′-butylidenebis(3-methyl-6-t-butylphenol), 4,4′-methylenebis(2,6-di-) t-butylphenol), 4,4'-bis(2,6-di-t-butylphenol), 2,2-(di-p-hydroxyphenyl)propane, 2,2-bis(3,5-di-t). -Butyl-4-hydroxyphenyl)propane, 4,4'-cyclohexylidenebis(2,6-t-butylphenol), hexamethyleneglycol-bis[3-(3,5-di-t-butyl-4-) Hydroxyphenyl)propionate], triethyleneglycol Bis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate], 2,2'-thio-[diethyl-3-(3,5-di-t-butyl-4-hydroxyphenyl) ) Propionate], 3,9-bis{1,1-dimethyl-2-[3-(3-t-butyl-4-hydroxy-5-methyl-phenyl)propionyloxy]ethyl}2,4,8,10 -Tetraoxaspiro[5,5]undecane, 4,4'-thiobis(3-methyl-6-t-butylphenol) and 2,2'-thiobis(4,6-di-t-butylresorcinol), polyphenols, For example, tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl). Butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis-[3,3'-bis(4'-hydroxy- 3'-t-butylphenyl)butyric acid]glycol ester, 2-(3',5'-di-t-butyl-4-hydroxyphenyl)methyl-4-(2",4"-di-t-butyl- 3"-hydroxyphenyl)methyl-6-t-butylphenol and 2,6-bis(2'-hydroxy-3'-t-butyl-5'-methylbenzyl)-4-methylphenol, and pt-butylphenol -Formaldehyde condensates and pt-butylphenol-acetaldehyde condensates.

Preferred phenolic antioxidants are the following trade names, "Irganox L-135" (from Ciba Specialty Chemicals Co.), "Yoshinox SS" (from Yoshitomi Seiyaku Co.), and "Antawa Kwage 400". Co.), "Antage W-500" (Kawaguchi Chi Kagaku Co.), "Antage W-300" (Kawaguchi Chi Kagaku Co.), "Irganox Cozy", "Ciba Species". Seiyaku Co.), "Irganox L115" (from Ciba Specialty Chemicals Co.), "Sumilizer GA80" (Sumitomo Cogai cuacu Caku), "Antage RC" (Kawaguchi). ), and "Yoshinox 930" (from Yoshitomi Seiyaku Co.).

The lubricating oil composition of the present invention can include a mixture of one or more phenolic antioxidants and one or more amine antioxidants.

In a preferred embodiment, the lubricating oil composition may comprise a single zinc dithiophosphate or a combination of two or more zinc dithiophosphates as an antiwear additive, wherein each or each zinc dithiophosphate is a dialkyl-, Selected from diaryl- or alkylaryl-zinc dithiophosphates.

The zinc dithiophosphate compound is preferably such that it provides 0.01% to 0.16% by weight, more preferably 0.06% to 0.12% by weight of phosphorus, based on the weight of the lubricating composition. Present in the lubricating composition in an amount.

式中、Ｒ^２〜Ｒ^５は同じでも異なっていてもよく、各々１〜２０個の炭素原子、好ましくは３〜１２個の炭素原子を含有する第一級アルキル基、３〜２０個の炭素原子、好ましくは３〜１２個の炭素原子を含有する第二級アルキル基、アリール基またはアルキル基で置換されたアリール基、であり、当該アルキル置換基は、１〜２０個の炭素原子、好ましくは３〜１８個の炭素原子を含有する。 Zinc dithiophosphate is an additive well known in the art and may conveniently be represented by the general formula II:

In the formula, R ^{2 to} R ⁵ may be the same or different and each is a primary alkyl group containing 1 to 20 carbon atoms, preferably 3 to 12 carbon atoms, 3 to 20 carbon atoms. An atom, preferably a secondary alkyl group containing 3 to 12 carbon atoms, an aryl group or an aryl group substituted with an alkyl group, wherein the alkyl substituent is 1 to 20 carbon atoms, preferably Contains 3 to 18 carbon atoms.

The zinc dithiophosphate compounds in which R ^{2 to} R ⁵ are all different from each other can be used alone or in a mixture with the zinc dithiophosphate compound in which R ^{2 to} R ⁵ are all the same.

Preferably, the or each zinc dithiophosphate used in the present invention is a zinc dialkyldithiophosphate.

Examples of suitable commercially available zinc dithiophosphates include zinc dithiophosphates available from Lubrizol Corporation under the trade names "Lz1097" and "Lz1395", and trade names "OLOA267" and "OLOA269R" available from Chevron Oronite. Zinc dithiophosphate, and zinc dithiophosphate available from Afton Chemical under the trade name "HITEC 7197"; Zinc dithiophosphate, zinc dithiophosphate available from Infineum under the trade name Infinium C9417, trade names "Lz677A", "Lz1095", and Zinc dithiophosphate available from Lubrizol Corporation under "Lz1371", zinc dithiophosphate available from Chevron Oronite under the trade name "OLOA262", and zinc dithiophosphate available from Afton Chemical under the trade name "HITEC7169"; and dithiophosphate. Zinc, zinc dithiophosphates available from Lubrizol Corporation under the trade names "Lz1370" and "Lz1373", and zinc dithiophosphates available from Chevron Oronite under the trade name "OLOA260".

The lubricating oil composition according to the present invention may generally include zinc dithiophosphate in the range of 0.4 to 1.2 wt% based on the total weight of the lubricating oil composition.

Additional or alternative antiwear additives may be conveniently and conveniently used in the compositions of this invention.

Typical detergents that may be used in the lubricating oils of the present invention include one or more salicylate and/or phenate and/or sulfonate detergents.

However, since metal organic and inorganic base salts used as detergents can contribute to the sulfated ash content of the lubricating oil composition, in preferred embodiments of the invention, the amount of such additives is minimized. It can be suppressed.

Further, salicylate detergents are preferred to maintain low sulfur levels.

Thus, in a preferred embodiment, the lubricating oil composition of the present invention can include one or more salicylate detergents.

The total sulfated ash content of the lubricating oil composition of the present invention is preferably at a level of 2.0 wt% or less, more preferably at a level of 1.0 wt% or less, based on the total weight of the lubricating oil composition, Most preferably, to maintain the level at 0.8 wt% or less, the detergent is preferably 0.05-20.0 wt%, more preferably 1. 2 wt%, based on the total weight of the lubricating oil composition. It is used in an amount ranging from 0 to 10.0% by weight, most preferably 2.0 to 5.0% by weight.

Further, the detergent is independently 10-500 mg. KOH/g range, more preferably 30-350 mg. KOH/g range, most preferably 50-300 mg. It is preferable to have a TBN (total alkalinity) value in the range of KOH/g.

Examples of viscosity index improvers that may be conveniently used in the lubricating oil composition of the present invention include styrene-butadiene copolymers, styrene-isoprene star and polymethacrylate copolymers, and ethylene-propylene copolymers. Such viscosity index improvers can be conveniently used in amounts ranging from 1 to 20% by weight, based on the total weight of the lubricating oil composition.

Polymethacrylates can be conveniently used in the lubricating oil compositions of the present invention as effective pour point depressants.

In addition, compounds such as alkenyl succinic acid or its ester moieties, benzotriazole compounds, and thiodiazole compounds can be conveniently used as corrosion inhibitors in the lubricating oil compositions of the present invention.

Compounds such as polysiloxanes, dimethylpolycyclohexane, and polyacrylates can be conveniently used in the lubricating oil compositions of the present invention as antifoam agents.

Compounds that may be conveniently used as seal fixatives or seal compatibilizers in the lubricating oil composition of the present invention include, for example, commercially available aromatic esters.

The lubricating compositions herein can be conveniently prepared using conventional compounding techniques by mixing the base oil with the liquid crystal compound and one or more additives at a temperature of 60°C.

The invention is illustrated below by the following examples, without any intention to limit the scope of the invention.

Various lubricating compositions were prepared by combining base oil (GTL 4, Fischer-Tropsch derived base oil having a kinematic viscosity at 100° C. of about 4 cSt, available from Shell) with ZDTP. ZDTP was added in an amount to provide 0.08 wt% phosphorus in the final lubricating composition. The formulation also contains a nitrogen-containing ashless dispersant (designated D1, D2, D3, or D4 in Table 1 below) in various amounts to provide a lubricating composition having various amounts of nitrogen ( It also contained 0.05 wt% N, 0.07 wt% N, or 0.1 wt% N) based on the weight of the final lubricating composition. Carbon black was also added to the lubricating composition in an amount equal to 5% by weight of the final lubricating composition to simulate the effect of the presence of soot in the lubricating composition.

The nitrogen-containing ashless dispersant used in this example was polyisobutylene succinimide having the properties listed in Table 1 below.

HFRR Abrasion Test The HFRR Abrasion Test was performed on the lubricant formulations. HFRR (High-Friction Reciprocating Rig) is a controlled reciprocating friction and wear test device used to evaluate fuel and lubricant performance. The test uses a 6 mm diameter steel ball that is loaded and reciprocated against the flat surface of a fixed steel disk immersed in a lubricant. At the end of each test, the balls and discs were removed from the test equipment, rinsed with toluene and isopropanol, and then treated with a 0.05 wt% solution of ethylenediaminetetraacetic acid (EDTA) for 60 seconds. This was to remove the ZDTP abrasion resistant film on the surface as it could interfere with optical system abrasion measurements. Topographic images were then acquired and analyzed using a SWLI Veeco Wyko model NT9100 to determine the amount of wear on the ball and disc wear scars. The instrument was set to Vertical Scan Interferometry (VSI) mode calibrated to measure rough surfaces with a detection range of nanometers.

The results of these abrasion tests are shown in Table 2 below.

Discussion From the results in Table 2, formulations containing polyisobutylene succinimide dispersants D3 and D4 (having functionality of 1.5 and 1.8, respectively) were tested for polyisobutylene succinimide dispersants D1 and D2 (1.3 and respectively). It can be seen that the wear is reduced (fewer measured wear scars) compared to the formulation containing 1.4 with a functionality Fv of 1.4).

Claims (10)

Use of a nitrogen-containing ashless dispersant in a lubricating composition for reducing wear in the presence of a zinc dithiophosphate compound and soot, said nitrogen-containing ashless dispersant having a functionality (F) of greater than 1.4. ,use. Use according to claim 1, wherein the nitrogen-containing ashless dispersant has a functionality (F) of greater than 1.5. Use according to claim 1 or 2, wherein the nitrogen-containing ashless dispersant comprises a functionalized oil-soluble polymeric hydrocarbon backbone derivatized with a nitrogen-containing nucleophile. Use according to claim 3, wherein the nitrogen-containing nucleophilic reactant is selected from amines, amino-alcohols, amides, or mixtures thereof. Use according to claim 3 or 4, wherein the nitrogen-containing nucleophilic reactant is an amine. Use according to any of claims 1-5, wherein the nitrogen-containing ashless dispersant comprises at least one polyalkenylsuccinimide which is the reaction product of a polyalkenyl-substituted succinic anhydride and a polyamine. 7. Use according to any of claims 1-6, wherein the nitrogen-containing ashless dispersant comprises at least one polyisobutylene succinimide. 8. The nitrogen-containing dispersant is present in the lubricating composition at a level to provide a nitrogen level of 0.001% to 15% by weight, based on the weight of the lubricating composition. Use according to any one of. The nitrogen-containing dispersant is present in the lubricating composition at a level to provide a nitrogen level of 0.05% to 0.1% by weight, based on the weight of the lubricating composition. The use according to any one of to 8. Use according to any of claims 1 to 9, wherein the lubricating composition comprises a base oil and one or more additives.