KR20040077911A - Lubricating oil compositions for internal combustion engines with improved wear performance - Google Patents

Abstract

The present invention is an oil of lubricating viscosity; About 0.05 to about 5 weight percent organic molybdenum compound; And about 0.1 to about 12 weight percent of a polyisobutenyl mono- and bis-succinimide borate having a molecular weight (Mn) of the polyisobutenyl group from about 500 to about 2300.

Description

LUBRICATING OIL COMPOSITIONS FOR INTERNAL COMBUSTION ENGINES WITH IMPROVED WEAR PERFORMANCE

Lubricants for internal combustion engines contain, in addition to one or more kinds of lubricating base oils, additives which improve the performance of the lubricating oil. Various additives such as detergents, dispersants, friction reducers, viscosity index improvers, antioxidants, corrosion inhibitors, antiwear additives, pour point depressants, seal swell additives, and antifoams are used in the lubricating oil composition.

During engine operation, oil insoluble oxidation by-products are produced. Dispersants help keep these byproducts in solution and thus reduce these precipitations on the metal surface. Dispersants are essentially free of ash or form ash. So-called ashless dispersants are organic materials that do not substantially form ash upon combustion.

Known classes of dispersants are generally long-chain substituted alkenyl succinic compounds, typically alkenyl succinic derivatives produced by the reaction of substituted succinic anhydrides with polyhydroxy or polyamino compounds. The long chains that make up the lipophilic molecular moiety that impart solubility in oil are typically polyolefins such as ethylene-propylene polymers or polyisobutylene groups. Many examples of this type of dispersant are well known commercially and are known in the literature. Exemplary US patents describing such dispersants include 3,172,892, 3,2145,707, 3,219,666, 3,316,177, 3,341,542, 3,444,170, 3,454,607, 3,541,012, 3,630,904, 3,632,511, 3,787,374 and 4,234,435, 3,275,554, 3,438,757, 3,565,804, 3,755,433, 3,822,209 and 5,084,197. Other types of dispersants include U.S. Pat. 3,726,882, 4,454,059, 3,329,658, 3,449,250, 3,519,565, 3,666,730, 3,687,849, 3,702,300, 4,100,082, 5,705,458. Further dispersants are disclosed, for example, in European Patent Application No. 471 071, to which reference is hereby made. Each of the aforementioned patents is incorporated herein by reference.

Abrasion and extreme pressure additives are also used in lubricating oil compositions. These additives help reduce wear on metal engine parts. Zinc dialkyldithiophosphate (ZDDP) has been used for many years as an antiwear agent. Alkylthiocarbamoyl compounds (e.g., a combination of molybdenum compounds (e.g. oxymolybdenum diisopropylphosphorodithioate sulfides) and phosphorus esters (e.g. dibutyl hydrogen phosphite) as antiwear additives in lubricants The use of bis (dibutyl) thiocarbamoyl) is disclosed in US Pat. No. 4,501,678, which is incorporated herein by reference in its entirety.

As there is a greater demand for lubricants in high performance engines, there is a need for oils with improved dispersant action.

Summary of the Invention

The present invention is an oil of lubricating viscosity; About 0.05 to about 5 weight percent organic molybdenum compound; And about 0.1 to about 12 weight percent of a polyisobutenyl mono- and bis-succinimide borate having a molecular weight (Mn) of the polyisobutenyl group from about 500 to about 2300.

The present invention relates to a lubricating oil composition suitable for use in an internal combustion engine.

Engine oils contain lubricant base oils and various additives. Such additives include detergents, dispersants, friction reducing agents, viscosity index enhancers, antioxidants, corrosion inhibitors, antiwear additives, pour point depressants, seal compatibility additives and antifoaming agents. To be effective, these additives must be oil-soluble or oil-dispersible. Oil-soluble means that the compound is soluble in base oil or lubricating oil compositions under normal mixing conditions.

The present invention is an oil of lubricating viscosity; About 0.05 to about 5 weight percent organic molybdenum compound; And about 0.1 to about 12 weight percent of a polyisobutenyl mono- and bis-succinimide borate having a molecular weight (Mn) of the polyisobutenyl group from about 500 to about 2300. The combination of these components shows a significant improvement in engine wear protection and lubricant related oxidation performance.

Another aspect of the invention is an oil of lubricating viscosity; About 0.02 to about 5 weight percent of the organic molybdenum compound; And about 0.1 to about 12 weight percent of a polyisobutenyl mono- and bis-succinimide borate having a molecular weight (Mn) of the polyisobutenyl group from about 500 to about 2300. Lubricant compositions comprising these additives also show significant improvements in engine wear protection and lubricant related oxidation performance. Another aspect of the present invention includes a method for producing a lubricating oil composition of the present invention.

Organic molybdenum sources useful in the present invention include molybdenum phosphorodithioates, molybdenum complexes of amines and / or alcohols or esters, molybdenum dithiocarbamates, and / or molybdenum (trimeric) dithiocarbamates or mixtures thereof But not limited to, all of the commonly available organic molybdenum compositions known in the art. Naturally, the molybdenum complex compound and molybdenum dithiocarbamate are preferable. The preferred concentration range of the molybdenum compound in the lubricating oil composition is from about 0.05 to about 5 weight percent, such molybdenum sources can be used effectively, and concentrations in the range from about 0.1 to about 3 weight percent are often more preferred, from about 0.15 to about 2 Most preferred is a concentration in the range of weight percent.

The medium molecular weight polyisobutenyl mono- and bis-succinimide borate compounds of the invention are optimal in the range of about 500 to about 2300, preferably 1000 to about 1600 (Mn) for the polyisobutylene moiety in the compound. Has a molecular weight. When used in conjunction with other elements of the invention, the compounds of the invention (polyisobutylene derivatives of about 1300 Mn) are essentially bis-succinimide borate ashless of higher molecular weight (polyisobutylene derivatives of about 2500 Mn). It is clearly observed that the improved features are compared with the dispersants. Preferred concentrations of the dispersant (s) (or mixtures of such dispersants) of the invention are from about 0.1 to about 12 weight percent or more. Concentrations of about 0.5 to about 8 weight percent are often preferred, and concentrations of about 2 to about 8 weight percent are most preferred. For the maximum performance benefit described above in the present invention, it is believed that at least a substantial portion of the succinimide is mono-succinimide or mono and bis-succinimide.

Mixtures of the above and other related dispersants, such as those lacking boron, basically high molecular weight, consisting essentially of mono-succinimide, bis-succinimide or mixtures thereof, made of different amines, terminal Use of these end-capped, polymers such as back-bone polyolefins other than polyisobutylene, such as ethylene, propylene-derived dispersants, and all mixtures thereof, is often useful.

The product can be post-reacted with various reactants such as sulfur, oxygen, formaldehyde, carboxylic acids such as oleic acid, anhydrides, polycyclic carbonates, and boron compounds such as borate esters or highly borated dispersants. The dispersant may be boronated with about 0.1 to about 5 moles of boron per mole of dispersant reaction product.

Another aspect of the present invention is an additional advantage for wear protection (ie, abrasion performance) in low- to non-phosphorus lubricant compositions. Low to non-phosphorus is included in the composition at a concentration of phosphorus from about 0% to about 0.05% by weight of the lubricating oil composition.

Base oil

A wide range of lubricants are known in the art. Lubricants useful in the present invention are natural and synthetic oils. Natural and synthetic oils (or mixtures thereof) may be used in the crude, refined or refined state (the latter also known as recycled or reprocessed oils). Crude oil is obtained directly from natural or synthetic sources and used without further purification. These include sail oil obtained directly from the retort operation, petroleum obtained directly from the primary distillation, and ester oil obtained directly from the esterification process. Refined oils are similar to the oils discussed for crude oil except that it is introduced into one or more refining steps to improve one or more lubricant properties. Those skilled in the art will be familiar with many purification methods. These methods include solvent extraction, secondary distillation, acid extraction, base extraction, filtration and pore perfusion. The refined oil is obtained using the oil used in the unit by a method similar to refined oil.

Groups I, II, III, IV and V are a broad range of base oils developed and defined by the American Petroleum Institute (API Publication 1509; www.API.org ). Group I based raw materials generally have a viscosity index of about 80 to 120 and contain at least about 0.03% sulfur and / or less than about 90% saturates. Group II based raw materials generally have a viscosity index of about 80 to 120 and contain up to about 0.03% sulfur and at least about 90% saturates. Group III raw materials generally have a viscosity index of at least about 120 and contain up to about 0.03% sulfur and at least about 90% saturates. Group IV includes polyalphaolefins (POA). Group V base raw materials include base raw materials not included in Groups I to IV. The table below summarizes the characteristics of each of these five groups.

Natural oils include animal oils, vegetable oils (eg castor oil and lard oil) and mineral oils. Treatment of animal and vegetable oils may yield advantageous thermal oxidative stability. Of the natural oils, mineral oils are preferred. Mineral oils are very broad, depending on their crude source, for example paraffinic, naphthenic or mixed paraffinic-naphthenic. Oils derived from char or sail are also useful in the present invention. Natural oils also vary according to the methods used for their preparation and purification, such as the distillation range and whether they are carried out directly, decomposed, hydrogen purified or solvent extracted.

Synthetic oils include hydrocarbon oils. Hydrocarbon oils include oils such as polymerized olefins and interpolymerized olefins (eg, polybutylene, polypropylene, propylene isobutylene copolymers, ethylene-olefin copolymers and ethylene-alphaolefin copolymers). Polyalphaolefin (PAO) oil based raw materials are commonly used synthetic hydrocarbon oils. For example, PAO derived from C ₈ , C ₁₀ , C ₁₂ , C ₁₄ olefins or mixtures thereof can be used. See US Pat. Nos. 4,956,122, 4,827,064 and 4,827,073, which are hereby incorporated by reference in their entirety.

The number average molecular weight of PAOs that are known and generally commercially available from sources such as ExxonMobil Chemical Company, Chevron-Phillips, BP-Amoco, etc. Although PAO consists of a viscosity of less than about 100 cSt (100 ° C.), it is generally about 250 to about 3,000. PAOs are generally alphaolefins, including but not limited to C ₂ to about C ₃₂ alphaolefins, preferably C ₈ to about C ₁₆ alpha olefins, for example 1-octene, 1-decene, 1-dodecene Low molecular weight hydrogenated polymers or oligomers. Preferred polyalphaolefins are poly-1-octene, poly-1-decene and poly-1-dodecene and mixtures thereof and mixed olefin-derived polyolefins. However, dimers of higher olefins in the range of C ₁₄ to C ₁₈ can be used to provide a low viscosity base stock of an acceptable low volatility. Depending on the viscosity grade and the starting oligomer, PAOs are mostly trimers and tetramers of the starting olefins, only small amounts are higher oligomers and have a viscosity of 1.5 to 12 cSt.

PAO fluids can be prepared by the use of a polymerization catalyst such as a preedel-craft catalyst (e.g., aluminum trichloride, boron trifluoride or boron trifluoride) and esters such as alcohols such as water, ethanol, propanol or butanol, carboxylic acids, ethyl acetate or ethyl propionate Complex compounds), which can be prepared conventionally by polymerization of alpha olefins. For example, the methods disclosed in US Pat. No. 4,149,178 or 3,382,291 are commonly used herein. PAO synthesis is disclosed in US Pat. Nos. 3,742,082, 3,769,363, 3,876,720, 4,239,930, 4,367,352, 4,413,156, 4,434,408, 4,910,355, 4,956,122 and 5,068,487. Dimers of C ₁₄ to C ₁₈ olefins are disclosed in US Pat. No. 4,218,330. All of these patents are incorporated herein by reference in their entirety.

Other useful synthetic lubricating base oils disclosed in, for example, the following documents, which are hereby incorporated by reference in their entirety, may also be used. See, "Synthetic Lubricants", Gunderson and Hart, Reinhold Publ. Corp., New York 1962].

In alkylated aromatic raw materials (e.g. hydrocarbyl aromatics), alkyl substituents are generally alkyl groups having 8 to 25 carbon atoms, typically 10 to 18 carbon atoms, and up to 3 such substituents, as described for alkyl benzene in the following literature: ACS Petroleum Chemistry Preprint 1053-1058, "Poly n-Alkylbenzene Compounds: A Class of Thermally Stable and Wide Liquid Range Fluids", Eapen et al., Phila. 1984]. Trialkyl benzenes can be produced by ring propolymerization of 1-alkaine of 8 to 12 carbon atoms as disclosed in US Pat. No. 5,055,626. Other alkylbenzenes are disclosed in European Patent Application No. 168534 and US Patent No. 4,658,072. Alkylbenzenes are used in particular as lubricant base oils and for papermaking oils for low temperature applications (Polar vehicle service and refrigerated oil). These are linear alkyls such as Vista Chem. Co, Huntsman Chemical Co., Chevron Chemical Co., and Nippon Oil Co. It is commercially available from the producer of benzene (LAB). Such linear alkylbenzenes generally have good low pour points and low temperature viscosities and viscosity index values greater than 100 and good solubility for additives. Other alkylated aromatics that can be used when needed are described, for example, in "Synthetic Lubricants and High Performance Functional Fluids", Dressler, H., chap 5, (RL Shubkin (Ed.)), Marcel Dekker, NY 1993].

Other useful lubricating base oils include base oils, including hydrogenated isomerate based raw materials and hydroisomerized wax raw materials (e.g., gas oils, slack waxes, fuel hydrocracked tower oils, etc.). -Tropsch) waxes, GTL base raw materials and base oils, and other wax isomerate hydroisomerization base raw materials and base oils, or mixtures thereof. Fischer Tropsch wax, the high boiling point residue of Fischer Tropsch synthesis, is a high paraffinic hydrocarbon with very low sulfur content. The hydrotreatment used in the production of these base stocks may utilize amorphous hydrocracking / hydroisomerization catalysts such as specialized lubricating oil hydrocracking (LHDC) catalysts or crystalline hydrocracking / hydroisomerization catalysts, preferably zeolite catalysts. have. For example, one useful catalyst is ZSM-48 disclosed in US Pat. No. 5,075,269, which is incorporated herein by reference in its entirety. Methods of preparing hydrocracked / hydroisomerized distillates and hydrocracked / hydroisomerized waxes are described in U.S. Pat.Nos. 2,817,693, 4,975,177, 4,921,594 and 4,897,178, as well as British Pat. 1,440,230 and 1,390,359. Particularly preferred methods are disclosed in European patent applications 464546 and 464547, which are incorporated herein by reference. Methods of using Fischer Tropsch wax feeds are disclosed in US Pat. Nos. 4,594,172 and 4,943,672. GTL base oils, Fischer-Tropsch wax derived base oils, and other wax-derived hydroisomerized (wax isomerate) base oils are preferably used in the present invention and are used in the range of about 3 to about 50 cSt, preferably about 3 to about 30 cSt. And, more preferably, can have a useful kinematic viscosity at 100 ° C. of about 3.5 to about 25 cSt, and can be represented by GTL 4 having a kinematic viscosity of about 4.0 cSt and a viscosity index of about 141 at 100 ° C. GTL base oils, Fischer Tropsch wax-derived base oils and other wax-derived hydroisomerized base oils can have useful pour points up to about -20 ° C. and under these conditions can have advantageous pour points up to about -25 ° C. and useful pour points Is about -30 to -40 ° C. Useful compositions of GTL base oils, Fischer-Tropsch wax derived base oils, and wax-derived hydroisomerized base oils are disclosed in US Pat. Nos. 6,080,301, 6,090,989, and 6,165,949, which are incorporated herein in their entirety. .

GTL base oils, Fischer-Tropsch wax derived base oils have advantageous kinematic advantages over conventional Group II and Group III base oils, which are very advantageously used in the present invention. GTL base oils can have a fairly high kinematic viscosity at 100 ° C. up to about 20-50 cSt, while commercial Group II base oils can have a kinematic viscosity at 100 ° C. up to about 15 cSt, and commercial Group III base oils have about 10 at 100 ° C. It may have a kinematic viscosity of less than cSt. The higher kinematic viscosity range of GTL base oils as compared to the more limited kinematic viscosity ranges of Group II and Group III base oils can provide additional advantageous advantages in formulating lubricating oil compositions when combined with the present invention. In addition, the exceptionally low sulfur content and other wax-derived hydroisomerized base oils of the base oils of GTL have very low total sulfur content when the appropriate olefin oligomers and / or alkyl aromatic base oils are combined with the present invention with low sulfur content. It can advantageously provide further advantages in lubricating oil compositions that can affect lubricating oil performance.

Alkylene oxide polymers and interpolymers and their derivatives containing modified terminal hydroxyl groups obtained by, for example, esterification or etherification are useful synthetic lubricants. By way of example, these oils may be polymerized with ethylene oxide or propylene oxide, alkyl and aryl ethers of these polyoxyalkylene polymers (e.g., methyl-polyisopropylene glycol ethers having an average molecular weight of about 1000, molecular weights of about 500 to 1000). Diphenyl ether of polyethylene glycol having, and diethyl ether of polypropylene glycol having a molecular weight of about 1000 to 1500) or their mono- and poly-carboxylic acid esters (acidic acid esters, mixed C _3-8 fatty acid esters, or tetra C ₁₃ oxo acid diesters of ethylene glycol).

Esters include useful substrate raw materials. Additive solubility and sealing suitability can be assured using esters such as esters of dibasic acids and monoalkanols and polyesters of monocarboxylic acids. Esters of the electronic type are, for example, phthalic acid, succinic acid, alkyl succinic acid, alkenyl succinic acid, maleic acid, azalaic acid, suveric acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl Esters of dicarboxylic acids such as malonic acid, alkenyl malonic acid and various alcohols such as butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, and the like. Specific examples of these types of esters are dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azlate, diisodecyl azlate, dioctyl Phthalates, diedecyl phthalates, diecosyl sebacates and the like.

Particularly useful synthetic esters are one or more polyhydric alcohols, preferably hindered polyols (eg neopentyl polyols such as neopentyl glycol, trimethylol ethane, 2-methyl-2-propyl-1,3-propane) Alkanoic acid (preferably caprylic acid, capric acid, lauric acid, myristic acid, palate) having at least about 4 carbon atoms for diols, trimethylol propane, pentaerythritol and dipentaerythritol C ₅ to C ₃₀ acids, such as saturated straight-chain fatty acids, such as metic acid, stearic acid, arachidic acid, and behenic acid or corresponding branched-chain fatty acids, or unsaturated fatty acids such as oleic acid, or mixtures of these substances).

Suitable synthetic ester components include esters of trimethylol propane, trimethylol butane, trimethylol ethane, pentaerythritol and / or dipentaerythritol with one or more monocarboxylic acids having from about 5 to about 10 carbon atoms. These esters are commercially widely available and include, for example, Mobil P-41 and P-51 esters (ExxonMobil Chemical Company).

Silicone oils are another class of useful synthetic lubricants. These oils include polyalkyl-, polyaryl-, polyalkoxy-, and polyaryloxy-siloxane oils and silicate oils. Examples of suitable silicone oils are tetraethyl silicate, tetraisopropyl silicate, tetra-2 (-ethylhexyl) silicate, tetra- (4-methyl-hexyl) silicate, tetra- (pt-butylphenyl) silicate, hexyl-4 (-Methyl-2-pentoxy) disiloxane, poly (methyl) siloxane and poly- (methyl-2-methylphenyl) siloxane.

Another class of synthetic lubricants is esters of phosphorus-containing acids. These include, for example, tricresyl phosphate, trioctyl phosphate, diethyl ester of decanephosphonic acid.

Another class of oils includes polymer tetrahydrofuran and the like.

In the present invention, base material having high paraffinic property is preferred. For example, Group II and / or Group III hydrotreated or hydrolyzed substrate stocks, or their synthetic counterparts such as polyalphaolefin lubricating oils, or mixtures of similar or similar oils, may be used in conjunction with the components of the invention. Often preferred as a raw material. Preferably, at least about 20% of the total composition should be composed of such Group II or Group III based raw materials, with about 30% often more preferred and often greater than about 80% even more preferred. Gas-to-liquid (GTL) raw materials may also be preferentially used as some or all of the base raw materials used to blend the finished lubricants with the components of the present invention. Mixtures of all or some of these substrates may be used and may be preferred. In one preferred mode, the base oil added to the lubrication system consists essentially of Group II and / or Group III based raw materials. Preferably, 20% of such Group II and / or Group III based raw materials may be used to demonstrate the advantages of the present invention. Optionally in this mode, small amounts of selective fluids such as the hydrocarbyl aromatics (eg, C ₁₆ monoalkylated naphthalenes) can be added.

In addition, co-based raw materials may be usefully used at lower concentrations than those such as basic base raw material (s) without reducing the elements of the present invention. These co-based feedstocks include polyalphaolefin oligomer based low and medium and high viscosity oils, dibasic acid esters, polyol esters, other hydrocarbon oils, hydrocarbyl aromatic supplements and the like. These co-substrate stocks may also contain some decene-derived trimers, provided that the Group II and / or Group III type base stock consists of at least about 50% of the total base stock contained in the fluids of the invention and Tetramers and also some Group I based raw materials.

Performance additives

The present invention provides effective amounts of additional lubricant components in lubricating oil compositions, such as, for example, polar and / or nonpolar lubricant base oils, and performance additives such as but not limited to antioxidants, metal and nonmetallic dispersants, metal and nonmetallic detergents, corrosion and Rust inhibitors, metal deactivators, antiwear agents (metals and nonmetals, phosphorus- and non-phosphorus, sulfur- and non-sulphuric types), extreme pressure additives (metals and nonmetals, phosphorus- and non-phosphorus, sulfur- and sulfur-based Types), anti-seizure agents, pour point depressants, wax modifiers, viscosity modifiers, seal fit agents, friction modifiers, lubricants, antifouling agents, colorants, antifoams, anti emulsifiers and the like. For many commonly used additives, see the following references: Klamann in Lubricants and Related Products, Verlag Chemie, Deerfield Beach, FL .; ISBN 0-89573-177-0]. The document also discusses a number of lubricant additives discussed below. See also, "Lubricant Additives", M. W. Ranney, Noyes Data Corporation of Parkridge, N.J. (1973).

Wear and extreme pressure additives

Additional antiwear additives may be used with the present invention. Although many different types of antiwear additives have existed for decades, the main antiwear additives for internal combustion engine crankcase oils are metal alkylthiophosphates, more specifically, primary metal components are zinc, or zinc dialkyldithio. Metal dialkyldithio phosphate that is phosphate (ZDDP). Popular ZDDP compounds are of the general formula Zn [SP (S) (OR ¹ ) (OR ² )] ₂ , wherein R ¹ and R ² are C ₁ -C ₁₈ alkyl groups, preferably C ₂ -C ₁₂ alkyl groups, or Is a mixture of these groups). These alkyl groups can be straight or branched chain. For example, suitable alkyl groups include isopropyl, 4-methyl-2-pentyl and isooctyl. ZDDP is generally used in amounts of about 0.4% to 1.4% by weight of the total lubricating oil composition, although sometimes some amount may be advantageously used.

However, it has been found from these additives that phosphorus adversely affects the catalyst phase in the catalytic converter and also adversely affects the oxygen sensor in automobiles. One way to minimize this effect is to replace some or all of the ZDDP with a phosphorus-free antiwear additive.

Various non-phosphorus additives are also used as antiwear additives. Sulfurized olefins are useful as antiwear and EP additives. Sulfur-containing olefins may be prepared by sulfidation or by various organic materials including aliphatic, arylaliphatic or cycloaliphatic olefin hydrocarbons having about 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms. The olefin compound contains one or more non-aromatic double bonds. Such compounds are defined by Formula I:

Where

R ³ to R ⁶ are independently hydrogen or hydrocarbon radicals. Preferred hydrocarbon radicals are alkyl or alkenyl radicals. Any two of R ³ to R ⁶ may be linked to form a cyclic ring. Additional information relating to sulfided olefins and their preparation is disclosed in US Pat. No. 4,941,984, which is incorporated herein by reference.

The use of polysulfides of thiophosphoric and thiophosphoric esters as lubricant additives is disclosed in US Pat. Nos. 2,443,264, 2,471,115, 2,526,497 and 2,591,577. The addition of phosphorothionyl polysulfides as antiwear, antioxidant and EP additives is disclosed in US Pat. No. 3,770,854. Alkylthiocarbamoyl compounds (e.g. The use of bis (dibutyl) thiocarbamoyl) is disclosed in US Pat. No. 4,501,678. U.S. Patent No. 4,758,362 discloses the use of carbamate additives to provide improved wear and extreme pressure properties. The use of thiocarbamates as antiwear additives is disclosed in US Pat. No. 5,693,598. Thiocarbamate / molybdenum complexes such as moly-sulfur alkyl dithiocarbamate trimer complexes (R═C ₈ -C ₁₈ alkyl) are also useful antiwear agents. Each of these patents is incorporated herein by reference in its entirety.

Esters of glycerol can be used as antiwear agents. For example, mono-, di-, and tri-oleates, mono-palmitates and mono-myristates can be used.

ZDDP is combined with other compositions that provide wear resistance. U.S. Pat.No. 5,034,141 discloses that a combination of a thiodigentogen compound (e.g. octylthiodogenogen) and a metal thiophosphate (e.g. ZDDP) can improve wear resistance. U.S. Patent No. 5,034,142 discloses improved abrasion resistance when a combination of metal alkoxyalkylgentate (e.g. nickel ethoxyethylgentate) and diezentogen (e.g. diethoxyethyl diegentogen) and ZDDP is used. It is disclosed.

The antiwear additive may be used in an amount of about 0.01 to 6% by weight, preferably about 0.01 to 4% by weight.

Viscosity Index Improver

Viscosity index improvers (known as VI enhancers, viscosity modifiers and viscosity improvers) provide lubricants with high and low temperature operability. These additives impart shear stability at high temperatures and acceptable viscosity at low temperatures.

Suitable viscosity index improvers include high molecular weight hydrocarbons, polyesters and viscosity index improver dispersants that function as both viscosity index improvers and dispersants. Typical molecular weights of these polymers are about 10,000 to 1,000,000, more preferably about 20,000 to 500,000, more preferably about 50,000 to 200,000.

Examples of suitable viscosity index improvers are polymers and copolymers of methacrylate, butadiene, olefins or alkylated styrenes. Polyisobutylene is a commonly used viscosity index improver. Another suitable viscosity index enhancer is polymethacrylate (eg, copolymers of various chain length alkyl methacrylates), some of which also act as pour point depressants. Other suitable viscosity index improvers include copolymers of ethylene and propylene, and hydrogenated block copolymers of styrene and isoprene and polyacrylates (eg, copolymers of various chain length acrylates). Specific examples include styrene-isoprene or styrene-butadiene-based polymers having a molecular weight of 50,000 to 200,000.

Viscosity index improvers can be used in amounts of about 0.01 to 6 weight percent, preferably about 0.01 to 4 weight percent.

Antioxidant

Antioxidants delay the oxidative decomposition of base oils during operation. This degradation can cause precipitation on the metal surface, the presence of sludge or an increase in viscosity in the lubricating oil. Those skilled in the art will know a wide variety of antioxidants useful in lubricating oil compositions. See Klamann in Lubricants and Related Products (cited above) and US Pat. Nos. 4,798,684 and 5,084,197, which are hereby incorporated by reference in their entirety. Useful antioxidants include hindered phenols. These phenolic antioxidants may be ashless (metal free) phenolic compounds or neutral or basic metal salts of certain phenolic compounds. Typical phenolic antioxidant compounds are hindered phenols which contain sterically hindered hydroxyl groups, which include derivatives of divalent aryl compounds in which the hydroxyl groups are in the o- or p-position relative to one another. Common phenolic antioxidants include hindered phenols substituted with C ₆₊ alkyl groups and alkylene coupled derivatives of these hindered phenols. Examples of phenolic substances of this type include 2-t-butyl-4-heptyl phenol, 2-t-butyl-4-octyl phenol, 2-t-butyl-4-dodecyl phenol, 2,6-di-t- Butyl-4-heptyl phenol, 2,6-di-t-butyl-4-dodecyl phenol, 2-methyl-6-t-butyl-4-heptyl phenol, and 2-methyl-6-t-butyl-4 There is dodecyl phenol. Other useful hindered mono-phenolic antioxidants include, for example, hindered 2,6-di-alkylphenol proprioone ester derivatives. Bisphenolic antioxidants can also be advantageously used in combination with the present invention. Examples of other coupled phenols are 2,2'-bis (6-t-butyl-4-heptyl phenol), 2,2'-bis (6-t-butyl-4-octyl phenol) and 2,2 ' -Bis (6-t-butyl-4-dodecyl phenol). Para-coupled bisphenols include, for example, 4,4'-bis (2,6-di-t-butyl phenol) and 4,4'-methylene-bis (2,6-di-t-butyl phenol) do.

Non-phenolic antioxidants that can be used include aromatic amine antioxidants and can be used alone or in combination with phenols. General examples of non-phenolic antioxidants are alkylated and non-alkylated aromatic amines, for example general formula R ⁸ R ⁹ R ¹⁰ N [where R ⁸ is an aliphatic, aromatic or substituted aromatic group and R ⁹ is aromatic Or a substituted aromatic group, R ¹⁰ is H, alkyl, aryl or R ¹¹ S (O) xR ¹² wherein R ¹¹ is an alkylene, alkenylene, or aralkylene group, and R ¹² is a higher alkyl group, al Is a kenyl, aryl, or alkaryl group, x is 0, 1, or 2). Aliphatic R ⁸ has 1 to about 20 carbon atoms, preferably about 6 to 12 carbon atoms. Such aliphatic groups are saturated aliphatic groups. Preferably, both R ⁸ and R ⁹ are aromatic or substituted aromatic groups, said aromatic groups may be conjugated ring aromatic groups such as naphthyl. Aromatic groups R ⁸ and R ⁹ may be bonded together with other groups such as S.

Typical aromatic amine antioxidants have alkyl substituents of about 6 or more carbon atoms. Examples of aliphatic groups include hexyl, heptyl, octyl, nonyl and decyl. Generally, aliphatic groups contain up to about 14 carbon atoms. Common types of amine antioxidants useful in the compositions of the present invention include diphenylamine, phenyl naphthylamine, phenothiazine, imidodibenzyl and diphenyl phenylene diamine. Mixtures of two or more aromatic amines are also useful. Polymeric amine antioxidants may also be used. Specific examples of aromatic amine antioxidants useful in the present invention include p, p'-dioctyldiphenylamine, t-octylphenyl-alpha-naphthylamine, phenyl-alphanaphthylamine and p-octylphenyl-alpha-naphthylamine It includes.

Sulfated alkyl phenols and their alkali or alkaline earth metal salts are also useful antioxidants. Low sulfur peroxide decomposers are useful as antioxidants.

Another class of antioxidants used in lubricating oil compositions are oil-soluble copper compounds. Any oil-soluble suitable copper compound may be blended into the lubricant. Examples of suitable copper antioxidants include copper dihydrocarbyl thio or dithio-phosphate and copper salts (naturally occurring or synthetic) of carboxylic acids. Other suitable copper salts include copper dithiocarbamate, sulfonate, phenate and acetylacetonate. Basic, neutral or acidic copper Cu (I) and / or Cu (II) salts derived from alkenyl succinic acids or acid anhydrides are known to be particularly useful.

Preferred antioxidants include hindered phenols, arylamines, low sulfur peroxide decomposers and other related ingredients. These antioxidants can be used individually or in combination with each other depending on the type. Such additives may be used in amounts of about 0.01 to 5% by weight, preferably about 0.01 to 1.5% by weight.

Freshener

Detergents are commonly used in lubricating oil compositions. Common detergents are anionic materials containing the long chain lipophilic portion of the molecule and small amounts of anionic or oleophobic portions of the molecule. The anionic portion of the detergent is generally derived from organic acids such as sulfuric acid, carboxylic acids, phosphoric acid, phenols or mixtures thereof. Counter ions are generally alkaline earth metals or alkali metals.

Salts containing substantially stoichiometric amounts of metals are described as neutral salts and have a total base number of 0 to 80 (TBN measured by ASTM D2896). Many compositions are overbased and contain large amounts of metal bases achieved by the reaction of excess metal compounds (such as metal hydroxides or oxides) with acidic gases (carbon dioxide). Useful detergents may be neutral, mildly overbased, or highly overbased.

It is preferred that at least some degree of detergent be overbased. Overbased detergents help neutralize the acidic impurities produced by the combustion process and are bound in the oil. In general, overbased materials have a ratio of metal ions to anionic portions of a detergent of about 1.05: 1 to 50: 1 on an equivalent basis. More preferably, the ratio is about 4: 1 to about 25: 1. The resulting detergents are generally overbased detergents having a TBN of at least about 150, often at least about 250 to 450. Preferably, the overbased cation is sodium, calcium or magnesium. Mixtures of detergents that differentiate TBN can be used in the present invention.

Preferred detergents include alkali or alkaline earth metal salts of sulfates, phenates, carboxylates, phosphates and salicylates.

Sulfonates can generally be prepared from sulfonic acids obtained by sulfonation of alkyl substituted aromatic hydrocarbons. Hydrocarbon examples include those obtained by alkylating benzene, toluene, xylene, naphthalene, biphenyl and their halogenated derivatives such as chlorobenzene, chlorotoluene and chloronaphthalene. The alkylating agent generally has about 3 to 70 carbon atoms. The alkali sulfonates generally contain about 9 to about 80 or more carbon atoms, more generally about 16 to 60 carbon atoms.

Klamann in Lubricants and Related Products, cited above, discloses a number of overbased metal salts of various sulfonic acids useful as detergents and dispersants in lubricating oils. Likewise, "Lubricant Additives", C. V. Smallheer and R. K. Smith, Lezius-Hiles Co., Cleveland, Ohio (1967) disclose a number of overbased sulfonates useful as dispersants / cleaners.

Alkaline earth metal phenates are another useful class of cleaning agents. These detergents can be prepared by reacting alkaline earth metal hydroxides or oxides (CaO, Ca (OH) ₂ , BaO, Ba (OH) ₂ , MgO, Mg (OH) ₂ ) with alkyl phenols or sulfided alkylphenols. Useful alkyl groups include straight or branched C ₁ -C ₃₀ alkyl groups, preferably C ₄ -C ₂₀ . Examples of suitable phenols include isobutylphenol, 2-ethylhexylphenol, nonylphenol, 1-ethyldecylphenol, and the like. It should be noted that the starting alkylphenols may each contain one or more alkyl substituents, each independently straight or branched. If non-sulfurized alkylphenols are used, the sulfided products can be obtained by methods well known in the art. Such methods include heating a mixture of alkylphenols and sulfiding agents (including elemental sulfur, sulfur halides such as sulfur dichloride, etc.) and reacting the sulfided phenols with alkaline earth metal bases.

Metal salts of carboxylic acids are also useful as detergents. These carboxylic acid detergents can be prepared by reacting a basic metal compound with one or more carboxylic acids and removing free water from the reaction product. These compounds can be overbased to produce the desired amount of TBN. Detergents made from salicylic acid are one preferred class of detergents derived from carboxylic acids. Useful salicylates include long chain alkyl salicylates. One useful class of compositions has Formula II:

Where

R is a hydrogen atom or an alkyl group having 1 to about 30 carbon atoms, n is an integer of 1 to 4, and M is an alkaline earth metal. Preferred R groups are C ₁₁ or more, preferably C ₁₃ or more alkyl chains. R may be optionally substituted with substituents that do not interfere with the function of the detergent. M is preferably calcium, magnesium or barium. More preferably, M is calcium.

Hydrocarbyl substituted salicylic acid can be prepared from phenol by Kolbe reaction. For additional information on the synthesis of these compounds, see US Pat. No. 3,595,791, which is incorporated herein by reference in its entirety. Metal salts of hydrocarbyl-substituted salicylic acid can be prepared by double decomposition of metal salts in polar solvents such as water or alcohols.

Alkaline earth metal phosphates are also used as cleaning agents.

The detergent may be a simple detergent or a complex detergent known as a hybrid. The latter can provide the properties of the two detergents without the need to mix separate materials. See, eg, US Pat. No. 6,034,039.

Preferred detergents include calcium phenate, calcium sulfonate, calcium salicylate, magnesium phenate, magnesium sulfonate, magnesium salicylate and other related compounds (including borated detergents). Generally, the total detergent concentration is about 0.01 to about 6.0 weight percent, preferably about 0.1 to 0.4 weight percent.

Pour point depressant

Conventional pour point depressants (also known as lubricant flow enhancers) may optionally be added to the compositions of the present invention. These pour point depressants are added to the lubricating oil compositions of the present invention to lower the minimum temperature at which the fluid can flow or flow. Examples of suitable pour point depressants include polymethacrylates, polyacrylates, polyarylamides, condensation products of haloparaffin waxes and aromatic compounds, terpolymers of vinyl carboxylate polymers and dialkylfumarates, vinyls of fatty acids and allyl vinyl ethers Contains esters. U.S. Patent Nos. 1,815,022, 2,015,748, 2,191,498, 2,387,501, 2,655,479, 2,666,746, 2,721,877, 2,721,878, 3,250,715 disclose useful pour point depressants and / or methods for their preparation It is. Each of these documents is hereby incorporated by reference in its entirety. Such additives may be used in amounts of about 0.01 to 5% by weight, preferably about 0.01 to 1.5% by weight.

Corrosion inhibitor

Preservatives are used to reduce the decomposition of metal parts in contact with the lubricant composition. Suitable preservatives include thiadiazoles. See, for example, US Pat. Nos. 2,719,125, 2,719,126, and 3,087,932, which are hereby incorporated by reference in their entirety. Such additives may be used in amounts of about 0.01 to 5% by weight, preferably about 0.01 to 1.5% by weight.

Sealing compatibility additive

Seal compatibility reagents help to inflate an elastomeric seal by causing a chemical reaction in the fluid or a physical change in the elastomer. Suitable sealing compatibility reagents for lubricating oils include organic phosphates, aromatic esters, aromatic hydrocarbons, esters (eg butylbenzyl phthalate) and polybutenyl succinic anhydrides. Such additives may be used in amounts of about 0.01 to 3 weight percent, preferably about 0.01 to 2 weight percent.

Antifoam

Defoamers may be advantageously added to the lubricating oil composition. These reagents delay the formation of stable bubbles. Organosilicon compounds and organic polymers are typical antifoaming agents. For example, polysiloxanes such as silicone oils or polydimethyl siloxanes provide antifoam properties. Antifoams are commercially available and can be used in conventional minor amounts with other additives such as anti emulsifiers. Typically the amount of these blended additives is less than 1%, often less than 0.1%.

And antirust additives

Antirust additives (or corrosion inhibitors) are additives that protect lubricated metal surfaces against chemical attack by water or other contaminants. A wide range of these additives are commercially available, see, for example, Klamann in Lubricants and Related Products, cited above.

One type of antirust additive is a polar compound that differentially wets the metal surface to protect the metal surface with an oil film. Another type of antirust additive is introduced into the water-in-oil emulsion to absorb water so that only oil contacts the metal surface. Another type of antirust additive is chemically bonded to the metal to create a non-reactive surface. Examples of suitable additives include zinc dithiophosphate, metal phenolates, basic metal sulfonates, fatty acids and amines. Such additives may be used in amounts of about 0.01 to 5% by weight, preferably about 0.01 to 1.5% by weight.

Friction modifier

Friction modifiers are any material (s) or fluids containing such materials that can change the coefficient of friction of any lubricant. Friction modifiers or lubricant agents or oil enhancers, also known as friction reducers, and other additives that change the coefficient of friction of other lubricant base oils, formulated lubricating compositions, or functional fluids are optionally combined with the base oil or lubricant composition of the present invention. Can be effectively used. Friction modifiers that lower the coefficient of friction are particularly advantageous when combined with the base oil and lubricating oil compositions of the present invention. Friction modifiers may include metal-containing compounds or materials as well as ashless compounds or materials, or mixtures thereof. Metal-containing friction modifiers may include metal salts or metal-ligand complexes in which the metal comprises an alkali, alkaline earth metal or transition group metal. Such metal-containing friction modifiers may also have low ash content. The transition metal may include Mo, Sb, Sn, Fe, Cu, Zn and the like. The ligands are alcohols, polyols, glycerol, partial ester glycerol, thiols, carboxylates, carbamates, thiocarbamates, dithiocarbamates, phosphates, thiophosphates, dithiophosphates, amides, imides, amines, thiazoles, thiadias Other polar molecular functional groups containing an effective amount of sol, dithiazole, diazole, triazole, O, N, S or P, individually or in combination. In particular, Mo-containing compounds, in particular Mo-dithiocarbamate, Mo (DTC), Mo-dithiophosphate, Mo (DTP), Mo-amine, Mo (Am), Mo-alcolate, Mo- Alcohol-amides and the like can be particularly effective.

Ashless friction modifiers also include lubricating oil materials that contain effective amounts of polar groups, such as hydroxyl-containing hydroaryl base oils, glycerides, partial glycerides, glyceride derivatives, and the like. Polar groups in friction modifiers may include hydrocarbyl groups containing an effective amount of O, N, S, or P, individually or in combination. Other friction modifiers that may be particularly effective are, for example, salts of fatty acids (both re-containing and ashless derivatives), fatty alcohols, fatty amides, fatty esters, hydroxyl-containing carboxylates and comparable synthetic long chain hydrocarbyl acids, alcohols , Amides, esters, hydroxy carboxylates and the like. In some cases fatty organic acids, fatty amines, and sulfurized fatty acids may be used as appropriate friction modifiers.

Useful concentrations of friction modifiers may range from about 0.01% to 10-15% by weight, more preferably from about 0.1% to 5% by weight. The concentration of molybdenum containing material is often described as the Mo metal concentration. Advantageous concentrations of Mo may be at least about 10-3000 ppm, with a preferred range of about 20-2000 ppm, and in some cases more preferred ranges of about 30-1000 ppm. All types of friction modifiers can be used alone or in combination with the materials of the present invention. Mixtures of two or more friction modifiers or mixtures of friction modifiers with optional surface active materials are also often often preferred.

Typical amount of additive

When the lubricating oil composition contains one or more of the additives mentioned above, the additive is mixed into the composition in an amount sufficient to perform the intended function. General amounts of such additives useful in the present invention are shown in the table below.

Most of the additives are shipped from manufacturers and used with certain amounts of base oil solvent in the formulation. Thus, the weight percentages in the table below as well as other amounts mentioned in this patent application relate to the amount of active ingredient (ie, non-solvent or non-dilution amount of the ingredient). The weight percentages mentioned below are based on the total weight of the lubricating oil composition.

Experiment

The type and amount of performance additives in the lubricant composition used in combination with the present invention are not limited by the examples illustrated herein.

Unless otherwise specified, the kinematic viscosity at 40 ° C. or 100 ° C. is determined according to ASTM test method D 445, the viscosity index is determined by ASTM test method D 2270, the pour point is determined by ASTM test method D 97, and TBN Is determined by ASTM test method D 2896.

Examples 2.1 to 2.4: Lubricant Wear Performance

The sequence IVA industry-certified engine test (ASTM Research Report RR: D02-1473) was used to evaluate the abrasion performance of the lubricating oils of different compositions under harsh conditions. The sequence IVA (Nissan KA24E) engine test measures the average wear at seven different points along the flank of a 12 cam lobe. For each cam lobe, the average wear at seven locations was summed to determine individual lobe seven-point wear. The 7-point wear of all 12 lobes is then averaged and the final average 7-point cam lobe results are reported in microns. Low wear values are beneficial and desirable. Oils with 7-point wear ≤120μ meet the sequence IVA wear requirements of performance categories such as API SL and ILSAC GF-3. The test results for the present invention are shown in Table 2.

Each of the oils tested contained about 7% hydrocarbyl aromatics including C ₁₆ monoalkylated naphthalene and was combined with additive packages including detergents, inhibitors, viscosity index enhancers, antifoams, detergent supplements, and the like.

Example 2.1 shows a sequence IVA wear performance of high wear oils with 210 micron wear, high molecular weight of about 4.5% (derived from about 2500 Mn polyisobutylene) bissuccinimide borate dispersant, about 1.0% Organic molybdenum compound (which does not contain sulfur, but is made from molybdenum and hydroxyl-containing nitrogen compounds), and about 0.5% secondary heterocyclic sulfur source. The formulation of Example 2.1 also contains 0% ZDDP, commonly used as an antiwear agent. This lubricant composition results in poor sequence IVA test performance of wear of 210 microns.

Example 2.2 shows a sequence IVA wear performance of high wear oils showing 289 micron wear, high molecular weight of about 4.5% (derived from about 2500 Mn polyisobutylene) bissuccinimide borate dispersant, about 0.35% It is combined with molybdenum (trimer) dithiocarbamate. This blend also contains 0% ZDDP, commonly used as an antiwear agent. This lubricant composition results in poor sequence IVA test performance of wear of 289 microns.

Example 2.3 unexpectedly shows sequence IVA wear performance of low wear oil and surprisingly 44 micron wear, which is much lower than the industry accepted standard. This significant wear performance oil is blended with a medium molecular weight of about 7% (derived from about 1300 Mn polyisobutylene) bissuccinimide borate dispersant, about 0.35% molybdenum (trimeric) dithiocarbamate. This oil also contains 0% ZDDP and 0% phosphorus. This lubricant component performed surprisingly well in the sequence IVA test resulting in only 44 micron wear.

Example 2.4 shows a sequence IVA wear performance of high wear oils with 134 micron wear and a medium molecular weight of about 7% (derived from about 1300 Mn polyisobutylene) mono- and bissuccinimide borate dispersants and molybdenum Formulated without addition. This oil also contains 0% ZDDP. This oil results in poor sequence IVA test performance of wear of 134 microns.

Table 1a shows another embodiment of the present invention. The abrasion advantage is another combination of molybdenum (trimeric) dithiocarbamate combined with a mono- and bissuccinimide borate dispersant of medium molecular weight (derived from about 1300 Mn polyisobutylene) and some hydrocarbyl aromatic based raw materials. It is expected that it can be obtained for. The present invention can also provide useful wear advantages in both hydrotreated and group III based raw materials. The concentration range for which this is expected is 0.1 to 2% molybdenum (trimeric) dithiocarbamate in combination with 2 to 10% borate dispersant, 3 to 15% hydrocarbyl aromatic. These embodiments can be usefully used in both hydrotreated substrate raw materials (eg HDT A) and GpIII based raw materials.

These results clearly show the useful effects of using medium-molecular weight mono- and bis-succinimide borate dispersants and organic molybdenum compounds. A useful effect is also derived from the addition of low levels of hydrocarbyl aromatics contained in the lubricants tested for wear inhibition in the sequence IVA test. It is also important to keep in mind that good wear performance is obtained in the absence of ZDDP or phosphorus. This means that the present invention is also useful for engines that require low levels of phosphorus (eg up to about 0.05%) or even phosphorus-deficient lubricating oil to protect certain emission catalysts and provide enhanced engine performance. In addition, since ZDDP produces sulphate ash, the additive combinations embodied in the present invention may be more useful for engines that require a reduced level of sulphate ash in lubricating oil to protect the engine exhaust after the treatment system.

The lubricating oil compositions cited below are examples of the present invention, which do not limit the present invention.

Examples 4.1 to 4.4: Lubricant Oxidation and Corrosion Performance

Synergistic combinations of mono- and bis-succinimide borate dispersants and organic molybdenum compounds improve lubricating oil oxidation and corrosion performance. The catalytic oxidation test is performed using several groups of different components described in detail in Table 4. The results illustrate the excellent properties of the compositions of the present invention. Various physical tests are performed on the oil. The ASTM test methods for these are listed in Table 4.

The catalytic oxidation test can be summarized as follows. The test lubricant composition is treated with an air stream that foams through the composition at a rate of 5 liters / hour. Metals commonly used as materials for engine structures are present in the composition. In other words:

(a) 15.6 square inches (sq. in.) of sand-blasted iron wire,

(b) 0.78 square inch polished copper wire,

(c) 0.87 square inch polished aluminum wire, and

(d) 0.167 square inch polished lead surface.

Lubricant performance is graded on the basis of the prevention of oil degradation measured by an increase in neutralization value (NN) and kinematic viscosity (KV) caused by acid formation or oxidation. Sludge formation during oxidation is visually assessed.

In Example 4.1, about 8% of medium molecular weight (derived from about 1300 Mn polyisobutylene) mono- and bissuccinimide borate dispersants and about 0.17% molybdenum (trimeric) dithiocarbamate, About 0.2% mixed zinc in polyalphaolefin oils (PAO) derived from olefins comprising decene and an additional about 7% hydrocarbyl aromatic fluid (“alkylated aromatic” essentially C ₁₆ monoalkylated naphthalene) It evaluated with dialkyl dithiophosphate (ZDDP). This oil worked remarkably well, resulting in an increase in final test viscosity of about 8.1% and unexpectedly good and low lead losses of about 0.8-mg without sludge. The oil has a very good performance in high temperature oxidation applications where worn metal or bearing metals can promote harmful oxidation effects.

In Example 4.2, about 8% medium molecular weight (derived from about 1300 Mn of polyisobutylene) mono- and bissuccinimide borate dispersants comprising 1-decene and an additional about 7% hydrocarbyl aromatic Evaluated with about 0.2% secondary zinc dialkyl dithiophosphate in polyalphaolefin oils (PAO) derived from olefins comprising liquid (basically C ₁₆ monoalkylated naphthalene). This oil exhibited poor performance resulting in an increase in final test viscosity of about 28.8%, and unexpectedly high and high lead losses of about 31.5-mg with very small amounts of sludge.

In Example 4.3, about 8% of relatively high molecular weight (derived from about 2300 Mn of polyisobutylene) unboronized mono- and bissuccinimide dispersants and about 0.17% molybdenum (trimeric) dithio Carbamate is approximately 0.2% 2 in polyalphaolefin oil (PAO) derived from olefins comprising 1-decene and an additional about 7% hydrocarbyl aromatic liquid (basically C ₁₆ monoalkylated naphthalene) It evaluated with primary zinc dialkyl dithiophosphate. This oil yielded an unexpectedly high and high loss of about 21.3 mg of lead with a small amount of sludge in the final test.

Table 5 shows the lubricant compositions expected to demonstrate the performance benefits of the present invention. Oxidation, sludge suppression, and corrosion inhibition advantages are based on medium molecular weight (derived from about 1300 Mn polyisobutylene) mono- and bissuccinimide borate dispersants, molybdenum (trimeric) dithiocarbamate, and some hydrocarbyl aromatic substrates It can be obtained for other combinations of ZDDP in combination with raw materials. The present invention can also provide the advantages of oxidation, sludge suppression, and corrosion inhibition in both hydrotreated and group III based stocks. The concentration range for which this is expected is 0.1 to 2% molybdenum (trimeric) dithiocarbamate in combination with 2 to 10% borate dispersant, 3 to 15% hydrocarbyl aromatic. These embodiments can be usefully used in both hydrotreated substrate stocks (eg HDT A) and Group III (GpIII) based stocks.

These results clarify the synergism provided by the mono- and bis-succinimide borate dispersants of medium molecular weight (derived from about 1300 Mn polyisobutylene) and the organic molybdenum compounds [molybdenum (trimeric) dithiocarbamate] Prove it. It is also important to keep in mind that oxidation, sludge suppression, and corrosion performance are obtained in formulations containing low levels of ZDDP or phosphorus. This means that the present invention is also useful for engines that require low levels of phosphorus (eg up to about 0.05%) to protect specific emission catalysts and provide enhanced engine performance. In addition, because ZDDP produces sulphate ash, the oxidation, sludge suppression, and corrosion inhibiting systems described herein may be useful in engines that require reduced sulphate ash oil to protect after treatment equipment.

Table 6 lists typical properties of the substrate raw materials used in the formulation of the oils described in Examples 2.1 to 5.8.

All US and other patents and patent applications and non-patent documents cited herein are incorporated by reference in their entirety.

Claims (15)

(a) at least one organic molybdenum compound; And (b) polyisobutenyl mono- and bis-succinimide borate salts having a molecular weight (Mn) of about 500 to about 2300 of the polyisobutenyl group. Lubricating oil additives comprising a. (a) oils of lubricating viscosity; (b) about 0.05 to about 5 weight percent of an organic molybdenum compound; And (c) about 0.1 to about 12 weight percent of polyisobutenyl mono- and bis-succinimide borate salts having a molecular weight (Mn) of about 500 to about 2300 of the polyisobutenyl group Lubricating oil composition comprising a. The method of claim 2, A lubricating oil composition wherein the oil of lubricating viscosity is selected from the group consisting of Group II, Group III and synthetic base materials. The method of claim 3, wherein The lubricant composition wherein the synthetic base material is polyalphaolefin. The method of claim 3, wherein A lubricating oil composition further comprising at least one sub-based raw material selected from the group consisting of hydrocarbyl aromatic and ester based raw materials. The method of claim 3, wherein A lubricating oil composition wherein the molybdenum compound is at least one compound selected from the group consisting of molybdenum phosphorodithioates, molybdenum complexes of amines, alcohols and / or esters, molybdenum dithiocarbamates and molybdenum (trimeric) dithiocarbamates. The method of claim 6, A lubricating oil composition wherein the organic molybdenum compound is present in an amount from about 0.1 to about 3 weight percent. The method of claim 7, wherein A lubricant composition wherein the polyisobutenyl mono- and bis-succinimide borate compounds are present in an amount of about 0.5 to about 8 weight percent. The method of claim 8, A lubricant composition wherein the lubricant is a Group II, Group III or Gas-to-Liquid (GTL) based raw material. The method according to any one of claims 2 to 9, A lubricant composition wherein the polyisobutenyl mono- and bis-succinimide borate compounds are present at about 20% by weight of total succinimide borate. (i) about 0.05 to about 5 weight percent of an organic molybdenum compound; And (ii) about 0.1 to about 12 weight percent of polyisobutenyl mono- and bis-succinimide borate salts having a molecular weight (Mn) of about 500 to about 2300 of the polyisobutenyl group Method for improving the wear performance of the lubricant composition comprising the step of adding to the lubricant. The polyisobutenyl mono- and bis-succinimide borate of claim 1, wherein the mono-succinimide is present at about 20% by weight of the total succinimide borate. (i) about 0.05 to about 5 weight percent of an organic molybdenum compound; And (ii) about 0.1 to about 12 weight percent of polyisobutenyl mono- and bis-succinimide borate salts having a molecular weight (Mn) of about 500 to about 2300 of the polyisobutenyl group Adding to the lubricating oil, the method of reducing lead loss under catalytic oxidation test conditions of the lubricating oil composition. (i) about 0.05 to about 5 weight percent of an organic molybdenum compound; And (ii) about 0.1 to about 12 weight percent of polyisobutenyl mono- and bis-succinimide borate salts having a molecular weight (Mn) of about 500 to about 2300 of the polyisobutenyl group Adding to the lubricating oil, the method for improving the inhibition of viscosity increase under high temperature oxidation conditions of the lubricating oil composition. 7. The lubricating oil composition of claim 6, wherein the molybdenum compound is present at a concentration sufficient to provide 20 ppm to 1000 ppm molybdenum.