CN120829803A - Lubricating compositions for gear fluids and wet brakes - Google Patents

Abstract

A gear fluid composition for lubricating a driveline comprising an extreme pressure agent that provides sulfur, a phosphorous-containing component and a hydrocarbyl amine effective to achieve transfer friction, extreme pressure and copper corrosion suitable for industrial and heavy duty lubrication.

Description

Lubricating composition for gear fluids and wet brakes

Technical Field

The present disclosure relates to a single lubricating composition suitable for wet brakes, gears, and differentials having improved extreme pressure, friction, and copper corrosion characteristics.

Background

In heavy or industrial applications, wet brakes, gears, differentials, and axles are typically lubricated by a common fluid provided via a single reservoir that must meet the extreme pressure requirements for lubricating the gears, transmission, and axles, but must also meet the friction requirements of the clutches and/or wet brakes. For example, axles, transfer cases, and/or differentials in heavy duty or industrial applications have a variety of mechanisms to provide power and/or torque transfer from, for example, an input pinion to the opposing wheels of the axle. Typically, lubricants used in such applications require fluids having suitable extreme pressure properties and suitable copper corrosion properties for the heavy loads to which the equipment is subjected. Various additives may be included in the lubricant to achieve the desired extreme pressure properties. For example, such lubricants may typically include a vulcanization additive to protect gears and other components from wear and scoring. However, while sulfidation additives may provide good extreme pressure and wear scar performance for the desired application, existing sulfidation additives tend to be detrimental to copper and copper alloys, resulting in unacceptable copper corrosion and friction.

Heavy and industrial equipment may also use wet clutches and/or wet brakes, wherein the same fluid used to lubricate the gears and axles may also be used in wet clutches or brake systems. In wet clutches or brake systems, the friction properties have to be controlled and additives suitable for extreme pressure and general lubrication are not always suitable for improving the friction properties.

However, with so many competing requirements for performance results that challenges are continually presented, balancing the compositional additives to achieve all performance attributes often presents challenges. For example, in many cases, altering one component within a lubricant composition or adding additional components to improve performance characteristics tends to adversely affect one or more other performance characteristics. Thus, it is difficult to balance all conflicting performance requirements with limited lubricant additives.

Disclosure of Invention

In one method or embodiment, a lubricating composition comprises one or more base oils of lubricating viscosity, up to about 3 wt.% of sulfur provided by an extreme pressure agent, a first phosphorus-containing component comprising a hydrocarbyl phosphonate monoester, wherein in some embodiments the first phosphorus-containing component is substantially free of amine or substantially free of amine (e.g., less than about 0.05 wt.% of an amine component, less than about 0.02 wt.% of an amine component, Less than about 0.01 weight percent of an amine component or no functional level of any amine component), a second phosphorus-containing component comprising an amine salt of a dialkylhydrothiophosphite, and a third phosphorus-containing component prepared by reacting a dialkyldithiophosphoric acid (preferably O, O' -bis (4-methyl-2-pentyl) dithiophosphoric acid) with ethylene oxide and/or propylene oxide to provide a first reaction product, and further reacting the first reaction product with phosphorus pentoxide to provide a second reaction product, and neutralizing the second reaction product with one or more aliphatic primary amines (preferably tertiary aliphatic primary amines) to provide a third amine-containing phosphorus component, a hydrocarbyl amine compound but less than about 0.1 weight percent of a hydrocarbyl amine compound, a thiadiazole or derivative thereof selected from the group consisting of a mono-hydrocarbyl thiol-substituted thiadiazole, And wherein the lubricating composition comprises from about 0.1 wt.% to about 0.5 wt.% of a total amine compound provided by the second phosphorus-containing component, the third phosphorus-containing component, and the hydrocarbyl amine compound, and wherein from about 15 wt.% to about 25 wt.% of the total amine compound is provided by the hydrocarbyl amine compound, greater than 50 wt.% of the total amine compound is provided by the second phosphorus-containing component, and from about 20 wt.% to about 30 wt.% of the total amine compound is provided by the third phosphorus-containing component. In other embodiments, the extreme pressure agent provides about 1.5 wt.% to about 3 wt.% sulfur, and in embodiments is provided by a blend of organosulfur compounds, wherein each organosulfur compound in the blend independently has the structure of formula R ₁-S_x-R₂, wherein R ₁ and R ₂ are independently C2 to C20 hydrocarbyl groups, and x is an integer from 2 to 6, wherein the blend of organosulfur compounds provides about 14,000ppm to about 16,000ppm of sulfur from organosulfur compounds having moieties S ₂ and S ₃, and no more than about 3000ppm of sulfur from organosulfur compounds having moieties S ₄、S₅ and/or S ₆ in the organosulfur compounds;

In yet other methods or embodiments, the lubricating composition described in the preceding paragraph may include other features or embodiments in any combination. These other features or embodiments may include one or more of the following, wherein the weight ratio of hydrocarbyl phosphonic acid monoester to total amine compound is from about 0.7:1 to about 1.8:1; and/or wherein the lubricating composition comprises from about 1.3 wt.% to about 3 wt.% of total sulfur, at least about 90 wt.% of which is provided by an extreme pressure agent as a blend of organosulfides compounds, wherein the blend has from about 10 wt.% to about 15 wt.% of organosulfides compounds having a portion of S ₂, from about 60 wt.% to about 70 wt.% of compounds having a portion of S ₃, and from about 12 wt.% to about 20 wt.% of compounds having a portion of S ₄, and/or wherein the blend of organosulfides compounds is provided by a first organosulfides reaction product and a second organosulfides reaction product, and/or wherein the hydrocarbyl amine compound is a tertiary aliphatic primary amine having from 4 to 20 carbon atoms in the alkyl group, and/or wherein the hydrocarbyl amine compound is selected from one or more of tertiary butylamine, tertiary hexylprimary amine, 1-methyl-1-amino-cyclohexane, tertiary octylprimary amine, tertiary decylamine, tertiary dodecylprimary amine, tertiary tetradecylamine, tertiary primary amine, tertiary octadecylprimary amine, tertiary primary amine, octacosylamine, and octacosylamine, tertiary oleylamine or a combination thereof, and/or wherein the lubricating composition comprises from about 1.5 wt.% to about 2.8 wt.% of a first organosulfided reaction product and from about 1.5 wt.% to about 2.8 wt.% of a second organosulfided reaction product, and/or wherein the lubricating composition comprises a weight ratio of the first organosulfided reaction product to the second organosulfided reaction product of from about 0.8:1 to about 1:0.8, and/or wherein R ₁ and R ₂ are independently selected from propyl, isopropyl, butyl, isobutyl, tert-butyl, or a combination thereof, and/or wherein the hydrocarbyl phosphonic monoester has the structure of formula II,

Wherein R ₅ is a C ₁₂ to C ₃₀ hydrocarbyl group, R ₆ is a C1 to C4 alkyl group, and R' is hydrogen or an alkyl group, and/or wherein the lubricating composition comprises from about 0.1 wt.% to about 0.8 wt.% of a hydrocarbyl phosphonate monoester, and/or wherein the lubricating composition further comprises a thiadiazole or derivative thereof selected from the group consisting of a monoalkylthiol-substituted thiadiazole, a dihydrocarbyl thiol-substituted thiadiazole, or a combination thereof, and/or wherein the thiadiazole is a1, 3, 4-thiadiazole or derivative thereof, and/or wherein the lubricating composition comprises about 1 wt.% or less of a thiadiazole or derivative thereof and/or wherein the thiadiazole or derivative thereof comprises one or more compounds having the structure of formula I:

Wherein each R ₃ is independently hydrogen or sulfur, each R ₄ is independently an alkyl group, n is an integer of 0 or 1, and if R ₃ is hydrogen, the integer n of the adjacent R ₄ moiety is 0, and if R ₃ is sulfur, the n of the adjacent R ₄ moiety is 1, and wherein at least one R ₃ is sulfur, and/or wherein the lubricating composition exhibits a damage of about 100mm ² or less in an FZG snap test at a 90 ℃ load level of 9 or more when compared to a reference fluid, and exhibits copper corrosion of about 200mg or less according to ASTM D130, wherein a hydrocarbyl phosphonate monoester dissolved in one or more base oils is utilized, and/or wherein the second phosphorus-containing component is an amine salt of dibutyl hydrogen phosphorothioate.

In still other embodiments and methods of the present disclosure, the use of any of the embodiments of the lubricating composition of the present disclosure is described that achieves a damage of about 100mm ² or less in FZG spring test at 90 ℃ load level 9 or more when compared to a reference fluid and achieves copper corrosion of about 200mg or less according to ASTM D130, wherein use of a hydrocarbyl phosphonic acid monoester dissolved in one or more base oils, particularly a lubricating composition comprising up to about 3 wt.% sulfur from an extreme pressure agent, a first phosphorus-containing component comprising a hydrocarbyl phosphonic acid monoester, wherein the first phosphorus-containing component is preferably substantially free of amine or free of amine as described above, a second phosphorus-containing component comprising an amine salt of a dialkyl hydrogen thiophosphite, and a third phosphorus-containing component prepared by reacting a dialkyl dithiophosphoric acid (preferably O, O' -di (4-methyl-2-pentyl) oxide) with a tertiary amine oxide and optionally a primary amine oxide, and providing a further reaction product comprising about 0.5 wt.% of a second phosphorus-containing component and 0.5 wt.% of a primary amine, and providing a reaction product of the reaction between the first phosphorus-containing component and a tertiary amine and a second phosphorus-containing component, wherein the reaction product is provided by about 0.0.5 wt.% of the reaction product of the reaction of the first phosphorus-containing component and the second phosphorus-containing component is preferably comprises an aliphatic amine and the primary amine oxide, And wherein about 15 wt% to about 25 wt% of the total amine compound is provided by the hydrocarbyl amine compound, greater than 50wt% of the total amine compound is provided by the second phosphorus-containing component, and about 20 wt% to about 30wt% of the total amine compound is provided by the third phosphorus-containing component to achieve a damage of about 100mm ² or less in an FZG snap test of 90 ℃ load grade 9 or more when compared to a reference fluid, and to achieve copper corrosion of about 200mg or less according to ASTM D130, wherein a hydrocarbyl phosphonate monoester dissolved in one or more base oils is utilized. In other methods, the extreme pressure agent comprises a blend of organosulfur compounds, wherein each organosulfur compound in the blend independently has the structure of formula R ₁-S_x-R₂, wherein R ₁ and R ₂ are independently C2 to C20 hydrocarbyl groups, and x is an integer from 2 to 6, wherein the blend of organosulfur compounds provides about 14,000ppm to about 16,000ppm of sulfur from the organosulfur compound having moieties S ₂ and S ₃ and no more than about 3000ppm of sulfur from the organosulfur compound having moieties S ₄、S₅ and/or S ₆ in the organosulfur compound.

Other methods or embodiments of systems including gears, differentials, and wet brakes are also described herein, all lubricated by any embodiment of the lubricating composition of the present disclosure, and wherein the lubricating composition is provided by a common fluid reservoir, tank, and/or sump. In yet other embodiments, described herein are methods of lubricating gears, differentials, and/or wet brakes with any of the embodiments of the lubricating composition of the present disclosure, and wherein the lubricating composition is provided by a common fluid reservoir, tank, and/or sump.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. The following term definitions are provided to clarify the meaning of certain terms as used herein.

Detailed Description

In one method or embodiment, disclosed herein are lubricating compositions suitable for gears, differentials, and axles, as well as limited slip applications, including wet clutches and/or wet brakes. The fluids herein have extreme pressure balance properties suitable for gear applications and friction properties suitable for wet clutch and/or wet brake applications. In one aspect, the lubricating compositions herein comprise at least one or more base oils of lubricating viscosity, an extreme pressure agent that contributes up to about 3 wt.% sulfur, up to about 2 wt.% sulfur, or greater than about 1.5 wt.% sulfur and no more than 3 wt.% sulfur (in some embodiments, the extreme pressure agent is provided by a blend of organosulfides compounds), at least three different phosphorus-containing components, one of which is preferably free of amines and the other two of which are preferably amine-containing phosphorus components, and a hydrocarbyl amine compound, and a thiadiazole or derivative thereof selected from the group consisting of a monohydrocarbylthhiol-substituted thiadiazole, a dihydrocarbyl thiol-substituted thiadiazole, or a combination thereof. As shown in the examples below, such compounds provide adequate extreme pressure properties.

In one embodiment, the lubricants herein include extreme pressure agents as a blend of organosulfur compounds to provide extreme pressure properties. In one aspect, each organosulfide compound in the blend independently has the structure of formula R ₁-S_x-R₂, wherein R ₁ and R ₂ are independently C2 to C20 hydrocarbyl groups, and x is an integer from 2 to 6. In other aspects, the blend of organosulfide compounds provides about 14,000ppm to about 16,000ppm of sulfur from organosulfide compounds having moieties S ₂ and S ₃, and less than 3000ppm, and preferably about 2500ppm to about 3000ppm of sulfur from organosulfide compounds having moieties S ₄、S₅ and/or S ₆ in the organosulfide compounds.

In other embodiments, the lubricants herein further comprise at least three different phosphorus-containing components as friction modifiers. In one aspect, the three phosphorus-containing components include (1) a first phosphorus-containing component in the form of a hydrocarbyl phosphonic acid monoester, and preferably the first phosphorus-containing component is substantially free of amine or free of amine as defined above, (2) a second phosphorus-containing component in the form of an amine salt of a dialkylhydrothiophosphite, and (3) a third phosphorus-containing component prepared by reacting dialkyldithiophosphoric acid (preferably O, O' -bis (4-methyl-2-pentyl) dithiophosphoric acid) with ethylene oxide and/or propylene oxide to provide a first reaction product, and further reacting the first reaction product with phosphorus pentoxide to provide a second reaction product, and neutralizing the second reaction product with one or more aliphatic primary amines (preferably tertiary aliphatic primary amines) to provide a third amine-containing phosphorus component.

In embodiments, the lubricants herein further comprise a hydrocarbyl amine compound. In one aspect, the hydrocarbyl amine compound is an aliphatic tertiary primary amine. In other aspects, the lubricants herein comprise less than about 0.1 wt.% of hydrocarbyl amine compound (and any additive package or additive concentrate comprises less than about 10 wt.% of hydrocarbyl amine compound).

In still other methods or embodiments, the lubricating compositions herein further comprise from about 0.1 wt.% to about 0.5 wt.% of a total amine compound contributed by the combination of the second phosphorus-containing component, the third phosphorus-containing component, and the hydrocarbyl amine compound. In another method or embodiment, about 15 wt% to about 25 wt% of the total amine compound is provided by the hydrocarbyl amine compound, greater than 50 wt% of the total amine compound is provided by the second phosphorus-containing component, and about 20 wt% to about 30 wt% of the total amine compound is provided by the third phosphorus-containing component. As shown in the examples below, the selection of three phosphorus-containing components in combination with a hydrocarbyl amine compound achieves the desired friction and copper corrosion properties, and the extreme pressure properties achieved with the organosulfides compounds. Each of the components of the lubricating composition herein will be described further below.

Extreme pressure agent

In some embodiments, the lubricating compositions herein include an extreme pressure agent that contributes up to about 3 wt.% sulfur, up to about 2 wt.% sulfur, or about 1 wt.% to about 3 wt.%, about 1.5 wt.% to about 3 wt.%, or about 1.5 wt.% to about 2 wt.% sulfur. In one embodiment, the extreme pressure agent is a blend of organosulfur compounds, which in one embodiment or method is provided by a combination of two or more different organosulfur compounds. In the method, the combined first and second organosulfide compounds provide up to about 3 wt.% sulfur (preferably up to 3 wt.% sulfur) and preferably from about 1 wt.% to about 3 wt.% sulfur (preferably from about 1 wt.% to about 3 wt.% or from about 1.5 wt.% to about 3 wt.% sulfur, or from about 1.5 wt.% to about 2 wt.% sulfur) in the composition. In other methods, the blend of organosulfur compounds provides at least about 90 wt.% or more of the total sulfur in the lubricating composition, and in other methods, the combined organosulfur compounds provide from about 90 wt.% to about 99 wt.% of the total sulfur in the lubricating composition, or from about 95 wt.% to about 98 wt.% of the total sulfur in the lubricating composition.

Each organosulfide compound in the blend is obtained from a reaction product that includes a specific combination/ratio of different organosulfide compounds, with a specific contribution of sulfur provided by the S ₂ to S ₆ portions of the compounds. More specifically, each organosulfide compound in the blends herein is a dihydrocarbyl sulfide compound having the structure of formula R ₁-S_x-R₂ (formula I), wherein R ₁ and R ₂ of formula I are independently C2 to C20 hydrocarbyl groups, and x is an integer suitable for achieving the sulfur contributions, ratios, and distributions herein, at least 2 (and preferably 2 to 6, 2 to 5, or 2 to 4). That is, each hydrocarbyl group of the organosulfide independently has 2 to 20 carbon atoms, preferably 3 to 10 carbon atoms, or more preferably 3 to 4 carbon atoms. In the method, each hydrocarbon group of the organosulfide compound may be aromatic or aliphatic, preferably the hydrocarbon group may be an aliphatic group such as alkyl, alkenyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, cycloalkenyl, etc., most preferably the hydrocarbon group is an alkyl group. Suitable alkyl groups may be propyl groups, isopropyl groups, butyl groups, isobutyl groups and/or tert-butyl groups. In the process, each hydrocarbyl group may be derived from an olefin. In such processes, the olefin may have from 2 to 20 carbon atoms or other ranges as described above.

Suitable olefins for preparing each of the organosulfides compounds herein may be mono-or di-substituted mono-olefins comprising 2 to 12 carbon atoms. Disubstituted mono-olefins are olefins having at least one double bond carbon atom containing two alkyl substituents. Examples of suitable olefins for deriving the organosulfides include ethylene, propylene, butene, isobutylene, 2-methyl-2-pentene, 2-methyl-2-butene, 2-methyl-1-butene, diisobutene, triisobutene and mixtures thereof, and dimers, trimers, tetramers and mixtures thereof may be suitable hydrocarbyl groups of each of the organosulfides herein.

Each of the organosulfides compounds herein can be prepared by reacting one or more of the above-described hydrocarbyl or olefinic compounds with a sulfur source (preferably, elemental sulfur or molten sulfur) in the presence or absence of a catalyst, such as an optional alkylamine catalyst, optionally at superatmospheric pressure, and then removing the low boiling material. Preferably, the sulfur source is substantially free of sulfur chloride, hydrogen sulfide, and combinations thereof, and in this context, the reactions herein have about 0.1 wt.% or less, about 0.05 wt.% or less, about 0.01 wt.% or less of sulfur chloride, hydrogen sulfide, or the like, or are free of sulfur chloride, hydrogen sulfide, or the like.

In embodiments, suitable organosulfides herein may be obtained, for example, by combining or reacting an olefin or hydrocarbyl compound with elemental sulfur in a ratio of moles of olefin/hydrocarbyl to grams of sulfur of from about 2:1 to about 1:2 in an autoclave or other reaction vessel suitable for conducting superatmospheric and high temperature reactions. In the process, the reaction may be conducted at a temperature of about 100 ℃ to about 200 ℃, at a pressure of about 250psi to about 1,000psi, and for a reaction time of about 2 hours to about 30 hours as desired to achieve the desired sulfur level for each additive in the mixture.

The reaction may be carried out in the presence or absence of a catalyst. If a catalyst is used, suitable catalysts may include amines and sulfur compounds such as dithiocarbamates and mercaptans such as, but not limited to, n-butylamine, n-octylamine, triethylamine, tetramethylthiuram disulfide, mercaptobenzothiazole, and the like. If a catalyst is desired, the catalyst may be used in an amount of about 0.01% to about 5.0% by weight of the reaction mixture or other amounts suitable for the particular application and sulfur level. The reaction may be carried out in the absence of oxygen.

The above-described sulfurized olefin or sulfurized hydrocarbyl intermediate may then be treated with an aqueous solution of caustic and/or alkali metal sulfide (such as sodium sulfide or potassium sulfide, and in some cases sodium sulfide), which may be prepared, for example, by mixing an aqueous solution of sodium hydrosulfide with a caustic solution (such as aqueous sodium hydroxide) in an amount effective to produce the desired sulfide distribution/ratio (e.g., -S _x -groups) for each reaction product. The solution may contain a co-solvent such as methanol. The sodium sulfide solution and the sulfiding intermediate may be combined in a stirred reactor and heated under an inert atmosphere (such as nitrogen) at a temperature of up to about 100 ℃, such as from about 50 ℃ to about 100 ℃, for about 30 minutes to about 4 hours, and in some cases, from about 1 hour to about 2 hours. The reaction mixture is then cooled and the organic product separated in the upper part of the aqueous layer is recovered. The amount of caustic can be varied as desired to form each of the organosulfides compounds and to provide sulfur contribution from the sulfur distribution/ratio thereof. That is, a first organosulfide compound that may have a high level of S ₃ sulfur groups may be treated with a higher level of caustic and a second organosulfide compound that has an equilibrium mixture of S ₃ groups and S ₄ groups may be treated with a lower amount of caustic. In one embodiment, the first organosulfur compound is treated with at least 2 times the amount of caustic as compared to the second organosulfur compound.

In one method or embodiment, the blend of organosulfides compounds of the lubricating composition herein (that is, all of the combined organosulfides compounds) provides about 14,000ppm to about 16,000ppm of sulfur from the organosulfides compound having S ₂ portion and S ₃ portion and about 2500ppm to about 3000ppm of sulfur from the organosulfides compound having S ₄ or more sulfur portions in the organosulfides compound, and preferably is part S ₄、S₅ and/or S ₆. In another method or embodiment, about 12 wt% to about 20 wt% of the organosulfide compounds in the blend have a S ₂ portion (in other methods, about 12 wt% to about 16 wt%), about 60 wt% to about 75 wt% of the organosulfide compounds in the blend have a S ₃ portion (in other methods, about 65 wt% to about 75 wt%), about 12 wt% to about 20 wt% of the organosulfide compounds in the blend have a S ₄ portion (in other methods, about 12 wt% to about 18 wt%), about 0.5 wt% to about 5wt% of the organosulfide compounds in the blend have a S ₅ portion (in other methods, about 0.5 wt% to about 3 wt%), and no more than about 1 wt% of the organosulfide compounds in the blend have a S ₆ portion (in other methods, no more than about 0.5 wt% or no functional amount). Such a blend of total organic sulfide compounds is preferably provided by at least two reaction products of different organic sulfide combinations. In another approach, the organosulfide compounds in the blend are combinations of organosulfide compounds having a selected weight ratio of S ₃ portion to S ₄ portion, such as a weight ratio of S ₃ portion to S ₄ portion of about 3:1 to about 6:1 (in other approaches, about 4:1 to about 5.5:1).

In any of the embodiments herein, the first organosulfide compound is the reaction product of an organosulfide compound that includes a high amount of a compound having a moiety S ₃, and preferably includes an organosulfide compound having a moiety S ₂ (in other embodiments, about 12 to about 16 wt.%), an organosulfide compound having a moiety S ₃ (in other embodiments, about 80 to about 90 wt.%), an organosulfide compound having a moiety S ₄ (in other embodiments, about 2 to about 5 wt.%), no more than about 1 wt.% of an organosulfide compound having a moiety S ₅ (in other embodiments, no more than about 0.5 wt.% or no functional amount), and no more than about 1 wt.% of an organosulfide compound having a moiety S ₆ (in other embodiments, no more than about 0.5 wt.% or no functional amount). In other methods, the first reaction product of the organosulfur compound can have a weight ratio of S ₃ to S ₄ moieties of about 20:1 to about 30:1 (in other methods, about 25:1 to about 30:1).

In any embodiment herein, the second organosulfide compound is the second reaction product of an organosulfide compound that comprises a more balanced blend of compounds having a S ₃ portion and a S ₄ portion, and preferably comprises an organosulfide compound having a S ₂ portion of about 12% to about 18% (in other embodiments, about 12% to about 16% by weight), an organosulfide compound having a S ₃ portion of about 50% to about 60% by weight (in other embodiments, about 55% to about 60% by weight), an organosulfide compound having a S ₄ portion of about 20% to about 30% by weight (in other embodiments, about 20% to about 26% by weight), an organosulfide compound having a S ₅ portion of about 1% to about 5% by weight (in other embodiments, about 1% to about 4% by weight), and an organosulfide compound having a S ₆ portion of no more than about 1% by weight (in other embodiments, no sulfide compound having no more than about 0.0% by weight). In other methods, the second reaction product of the organosulfur compound can have a weight ratio of S ₃ moiety to S ₄ moiety of about 1.5:1 to about 4:1 (in other methods, about 2:1 to about 3:1).

In yet other methods or embodiments, the lubricating compositions herein can include a treat rate of the organosulfur compound provided by (1) from about 1.5 wt.% to about 2.8 wt.% of the first reaction product of the organosulfur compound (in other methods, from about 1.6 wt.% to about 2.2 wt.%) and (2) from about 1.5 wt.% to about 2.8 wt.% of the second reaction product of the organosulfur compound (in other methods, from about 1.6 wt.% to about 2.2 wt.%). Of course, the amount of each reaction product will depend on the composition of the sulfur compound within each reaction product. In some methods, it is preferred that the final fluid comprises no more than 3wt% sulfur compounds having S ₅ sulfur groups, greater than about 60wt% sulfur compounds having S ₃ groups, and/or less than 20wt% sulfur compounds having S ₄ groups. In still other methods, the lubricating composition can have a weight ratio of the first organosulfide reaction product to the second organosulfide reaction product of about 0.8:1 to about 1:0.8.

As shown in the examples below, the particular combination of organosulfides reaction products was selected to help achieve good friction performance, good wear scar performance, and good copper corrosion performance. Furthermore, high levels of sulfur are generally detrimental to copper corrosion, but when the lubricating compositions herein include a particular distribution/ratio of organic sulfur compounds, the compositions may surprisingly include higher levels of total sulfur, yet still achieve better copper corrosion performance than a comparative fluid having lower levels of sulfur but not falling within certain sulfur distributions identified herein.

First phosphorus-containing component

The lubricating composition herein comprises a first phosphorus-containing component in the form of an amine-free or substantially amine-free hydrocarbyl phosphonate monoester (that is, contributing less than about 0.05 wt.% of an amine compound, less than 0.02 wt.% of an amine compound, less than about 0.01 wt.% of an amine compound, or no functional level of any amine compound). In some methods, the amine-free hydrocarbyl phosphonate monoester has the structure of formula II,

Wherein the hydrocarbyl moiety R ₅ of formula II is a linear or branched C12 to C30 hydrocarbyl chain, the monoester moiety R ₆ of formula II is a linear or branched C1 to C4 alkyl group, and R' is hydrogen or an alkyl group, such as a C1 to C30 alkyl group. In a preferred method, R ₆ is a methyl group or an ethyl group, and R' is hydrogen. The amount of the phosphonic acid monoester (such as the hydrocarbyl phosphonic acid monoester described herein) is from about 0.1 wt.% to about 1 wt.%, in other methods from about 0.1 wt.% to about 0.7 wt.%, or in yet other methods from about 0.1 wt.% to about 0.5 wt.%, based on the total weight of the lubricating oil composition.

Suitable phosphonates may also include primary alkyl acyclic hydrocarbyl phosphonates wherein the primary alkyl group comprises 1 to 4 carbon atoms and wherein the acyclic hydrocarbyl group bonded to the phosphorus atom contains 12 to 30 carbon atoms and in some processes is a linear hydrocarbyl group free of acetylenic unsaturation. In other processes, the acyclic hydrocarbyl group comprises 12 to 24 carbon atoms, and in still other processes, comprises 12 to 20 carbon atoms.

Exemplary phosphonate compounds for use in the first phosphorus-containing component herein include methyl hydrocarbyl phosphonate, ethyl hydrocarbyl phosphonate, propyl hydrocarbyl phosphonate, butyl hydrocarbyl phosphonate, isobutyl hydrocarbyl phosphonate, and wherein the hydrocarbyl group is preferably linear, saturated, or contains one or more olefinic double bonds in each case, wherein each double bond is preferably an internal double bond. Other suitable compounds include compounds in which the phosphorus atom is bonded to a hydrocarbon group containing 16 to 20 carbon atoms or 18 to 20 carbon atoms. Particularly suitable phosphonate monoester compounds may be ethyl octadecylphosphonate or methyl octadecylphosphonate. Other examples of suitable phosphonic acid monoesters include, but are not limited to, methyl triacontyl phosphonate, methyl eicosanyl phosphonate, methyl hexadecyl phosphonate, methyl tetradecyl phosphonate, methyl hexadecyl phosphonate, methyl dodecyl phosphonate, ethyl triacontyl phosphonate, ethyl eicosanyl phosphonate, ethyl hexadecyl phosphonate, ethyl tetradecyl phosphonate, ethyl hexadecyl phosphonate, ethyl dodecyl phosphonate, ethyl dodecenyl phosphonate, and the like, and mixtures thereof.

A second phosphorus-containing component

The lubricating composition herein includes a second phosphorus-containing component in the form of an amine salt of a dihydrocarbyl hydrogen thiophosphite. The second phosphorus-containing component provides an amine compound from the amine salt to the lubricant. In some embodiments, suitable compounds for the second phosphorus-containing component include phosphoric acid, organic esters of phosphorous acid, or amine salts thereof. For example, the second phosphorus-containing component may include one or more of a dihydrocarbyl phosphite, a trialkyl phosphite, a dihydrocarbyl phosphate, a trialkyl phosphate, any sulfur analogues thereof, and any amine salts thereof. More specifically, in some preferred embodiments, the second phosphorus-containing component may comprise an amine salt of at least one dibutyl hydrothiophosphite. In methods or embodiments herein, the lubricating composition comprises from about 0.1 wt.% to about 0.8 wt.% of the second amine phosphorus-containing component (in other methods, from about 0.2 wt.% to about 0.8 wt.%, or from about 0.4 wt.% to about 0.8 wt.%).

The second phosphorus-containing component also provides an amine compound to the lubricants herein, and in embodiments, is preferably salified with a hydrocarbyl amine. In embodiments, the hydrocarbyl amine salt contributes from about 0.1 wt.% to about 0.3 wt.% of the amine compound (in other embodiments, from about 0.2 wt.% to about 0.3 wt.% of the amine compound) to the lubricating composition herein. In the process, the amine salt is a linear primary aliphatic amine having a C6 to C30 hydrocarbyl group or in other processes having a C10 to C20 hydrocarbyl group.

In other methods, suitable amines for salt formation of the second phosphorus-containing component herein include aliphatic amines, aromatic amines, cycloaliphatic amines, heterocyclic amines, carbocyclic amines, or combinations thereof. Preferably, the amine is a linear aliphatic tertiary amine. In embodiments, the amine may have 4 to 30 carbon atoms. In some methods, the amine can include an aliphatic primary amine containing at least about 8 carbon atoms and can have the structure R ₁₄NH₂, where R ₁₄ is, for example, an aliphatic group such as t-octyl, t-dodecyl, t-tetradecyl, t-octadecyl, hexadecyl, docosyl, stearyl, eicosyl, docosyl, tetracosyl, hexatriacontyl, and hexafifty alkyl. In other embodiments, suitable amines may be C11 to C20 tertiary alkyl primary amines, more preferably C11 to C14 tertiary alkyl primary amines. Other amines may include, but are not limited to, cyclohexylamine, N-hexylamine, dodecylamine, behenyl amine, melissyl amine, N-methyl-octylamine, butylamine, oleylamine, myristylamine, N-dodecyltrimethylene diamine, aniline, o-toluidine, benzidine, phenylenediamine, N '-di-sec-butylphenylenediamine, beta-naphthylamine, alpha-naphthylamine, morpholine, piperazine, methane diamine, cyclopentylamine, ethylenediamine, hexamethylenetetramine, octamethylenediamine, and N, N' -dibutylphenylenediamine.

Third phosphorus-containing component

In the method, the third phosphorus-containing component of the lubricating composition herein is an amine-containing and phosphorus-containing component in the form of a reaction product prepared by reacting a dialkyldithiophosphoric acid, such as an O, O-dihydrocarbyldithiophosphoric acid, with an epoxide to produce a first reaction product. The first reaction product is then reacted with phosphorus pentoxide to provide a second reaction product. The second reaction product is then neutralized with an amine compound to provide a third phosphorus-containing component of the lubricant herein.

In a method or embodiment, a plurality of dithiophosphoric acids may be used to form the third phosphorus-containing component. In the process, the starting dithiophosphoric acid used to prepare the third phosphorus product may have the general structure of formula III

Wherein R ₈ and R ₉ of formula III may be C1 to C30 hydrocarbyl groups, preferably straight or branched alkyl groups such as butyl, lauryl, 4-methyl-2-pentyl groups, and the like. The starting acid of formula III may be prepared by reacting phosphorus pentasulfide with a suitable alcohol or phenol. In one embodiment, the alcohol or phenol may be reacted with phosphorus pentasulfide at a temperature of from about 50 ℃ to about 200 ℃.

In embodiments, suitable epoxides for forming the first reaction product include those of formula IV

Wherein R ₁₀、R₁₁、R₁₂ and R ₁₃ of formula IV are each independently hydrogen or any C ₁ to C ₃₀ hydrocarbyl group and may preferably include oxides of ethylene oxide, propylene oxide, styrene oxide, alpha-methyl styrene oxide, combinations thereof, and the like. Preferred oxides include ethylene oxide and/or propylene oxide.

In the process, suitable amine compounds for neutralizing the second reaction product include aliphatic amines, aromatic amines, cycloaliphatic amines, heterocyclic amines, carbocyclic amines, or combinations thereof. In embodiments, the amine may have 4 to 30 carbon atoms. In some methods, the amine can include an aliphatic primary amine containing at least about 8 carbon atoms and can have the structure R ₁₄NH₂, where R ₁₄ is, for example, an aliphatic group such as t-octyl, t-dodecyl, t-tetradecyl, t-octadecyl, hexadecyl, docosyl, stearyl, eicosyl, docosyl, tetracosyl, hexatriacontyl, and hexafifty alkyl. In other embodiments, suitable amines may be tertiary aliphatic primary amines, such as C11 to C20 tertiary alkyl primary amines, more preferably C11 to C14 tertiary alkyl primary amines. Other amines may include, but are not limited to, cyclohexylamine, N-hexylamine, dodecylamine, behenyl amine, melissyl amine, N-methyl-octylamine, butylamine, oleylamine, myristylamine, N-dodecyltrimethylene diamine, aniline, o-toluidine, benzidine, phenylenediamine, N '-di-sec-butylphenylenediamine, beta-naphthylamine, alpha-naphthylamine, morpholine, piperazine, methane diamine, cyclopentylamine, ethylenediamine, hexamethylenetetramine, octamethylenediamine, and N, N' -dibutylphenylenediamine. In the methods, the third phosphorus compound herein can contribute from about 0.1 wt.% to about 0.3 wt.% of the amine compound (in other methods, from about 0.1 wt.% to about 0.2 wt.%) to the lubricating composition herein.

In other optional methods, hydroxy-substituted amines may also be used to neutralize the second reaction product. Exemplary hydroxy-substituted amines may include ethanolamine, diethanolamine, triethanolamine, isopropanolamine, para-aminophenol, 4-amino-naphthol-1, 8-amino-naphthol-1, beta-aminoarubicin, 2-amino-2-ethyl-1, 3-propanediol, 4-amino-4' -hydroxy-diphenylether, 2-amino-resorcinol, N-4-hydroxybutyl-dodecylamine, N-2-hydroxyethyl-N-octylamine, N-2-hydroxypropyl dinonamine, N-di- (3-hydroxypropyl) -t-dodecylamine, N-hydroxy triethoxyethyl-t-tetradecylamine, N-2-hydroxyethyl-t-dodecylamine, N-hydroxy hexapropoxypropyl-t-octadecylamine, and N-5-hydroxypentyldi-N-decylamine.

Hydrocarbyl amine compounds

The first phosphorus-containing component in the form of a phosphonate monoester may precipitate out of solution or cause a small amount of precipitation. If desired, a limited amount of an additional hydrocarbyl amine compound is further added to the lubricating composition herein. Such hydrocarbyl amine compounds preferably include linear aliphatic tertiary amines.

In embodiments or methods herein, the lubricating combination comprises less than about 0.1 wt.% of the hydrocarbyl amine compound (preferably, about 0.099 wt.% or less, and more preferably, about 0.098 wt.% or less), and any additive concentrate comprises less than about 10 wt.% of the hydrocarbyl amine compound. Exemplary hydrocarbyl amine compounds include dihydrocarbyl (mono) thiophosphates and may include those having a hydrocarbyl moiety of 2 to 24 carbon saturated or unsaturated groups, alkyl groups, alkenyl groups, and/or aromatic hydrocarbon groups. In other methods, suitable hydrocarbyl amine compounds may be primary hydrocarbyl amines having 4 to 30 carbon atoms. Fatty amines may also be used and may include alkylamines such as n-hexylamine, n-octylamine, n-decylamine, n-dodecylamine, n-pentadecylamine, n-hexadecylamine, n-octadecylamine (stearylamine), and the like. In yet other methods, the hydrocarbyl amines can be those derived from tertiary aliphatic primary amines having 4 to 30 carbon atoms in the alkyl group. Mixtures of amines may also be beneficial, such as mixtures of C11 to C14 tertiary alkyl primary amines and/or mixtures of C18 to C22 tertiary alkyl primary amines.

Thus, the lubricating composition herein includes the total amount of amine compounds contributed by three sources, including a hydrocarbyl amine compound, an amine compound contributed by the second phosphorus-containing component, and an amine compound contributed by the third phosphorus-containing component. In other methods or embodiments, the lubricating compositions herein comprise from about 0.1 wt.% to about 0.5 wt.% of the total amine compound provided by the combination of the second amine-containing phosphorus component, the third amine-containing phosphorus component, and the hydrocarbyl amine compound. In still other methods, the total amine compounds in the lubricating compositions herein include from about 15 wt.% to about 25 wt.% (in other methods, from about 18 wt.% to about 22 wt.%) of the total amine compounds provided by the hydrocarbyl amine compound, greater than 50 wt.% (in other methods, from about 50 wt.% to about 60 wt.%) of the total amine compounds provided by the second phosphorus-containing component, and from about 20 wt.% to about 30 wt.% (in other methods, from about 25 wt.% to about 30 wt.%) of the total amine compounds provided by the third phosphorus-containing component.

Without wishing to be bound by theory, a certain portion of the amine contributed by the second phosphorus-containing component and the third phosphorus-containing component may help dissolve the first phosphorus-containing component, but such amounts are insufficient to maintain the first phosphorus-containing component in solution. As shown in the examples below, less than 0.1 weight percent of the additional hydrocarbyl amine compound is combined with at least a portion of the amine compounds from the first phosphorus-containing component and the second phosphorus-containing component to maintain the first phosphorus-containing component in solution.

In yet further embodiments, the weight ratio of the first phosphorus-containing component, preferably the hydrocarbyl phosphonate monoester, to the total amine compounds (e.g., amine compounds from the hydrocarbyl amine, amine compounds from the second phosphorus-containing component, and amine compounds from the third phosphorus-containing component) is from about 0.7:1 to about 1.8:1, and in other methods from about 1:1 to about 1.5:1.

Certain other phosphorus friction modifiers

The lubricating compositions herein may also be free or substantially free of certain other phosphorus friction modifiers. While not wishing to be bound by theory, it is believed that a phosphonate diester, such as a dialkyl hydrocarbyl phosphonate (and particularly dimethyl octadecylphosphonate), may adversely affect copper corrosion. For example, it is believed that such phosphonic acid diesters may react or interact with the thiadiazole additives of the compositions herein, resulting in undesirable reaction products or other impurities that may degrade copper corrosion. To this end, in some methods or embodiments, the lubricating compositions herein may be free or substantially free of phosphonate diester, such as less than about 0.8 wt%, less than 0.5wt%, less than about 0.25 wt%, less than about 0.1 wt%, or do not include a functional amount of phosphonate diester.

Thiadiazole additive

The lubricating compositions herein may also include a thiadiazole or derivative thereof. In the method, the lubricating composition may include about 0.1 wt.% or more of the thiadiazole or derivative thereof. In some methods, the lubricating composition can include about 0.1 wt.% to about 1 wt.% or about 0.1 wt.% to about 0.5 wt.% thiadiazole or derivative thereof. In some embodiments, the thiadiazole or derivative thereof may be a mixture of thiadiazole compounds and/or hydrocarbyl-substituted derivatives thereof.

In some methods, the thiadiazole or derivative thereof provides at least about 350ppm sulfur to the lubricating composition, in other methods, at least about 380ppm sulfur, at least about 400ppm sulfur, at least about 500ppm sulfur, at least about 600ppm sulfur, or at least about 700ppm sulfur to about 2500ppm or less, about 2000ppm or less, about 1500ppm or less, or about 1000ppm or less.

In the method, the thiadiazole or derivative thereof comprises one or more compounds having the structure of formula I:

Wherein each R ₃ is independently hydrogen or sulfur, each R ₄ is independently an alkyl group, n is an integer of 0 or 1, and if R ₃ is hydrogen, the integer n of the adjacent R ₄ moiety is 0, and if R ₃ is sulfur, the n of the adjacent R ₄ moiety is 1, with the proviso that at least one R ₃ is sulfur. In other methods, the thiadiazole additive is a blend of compounds of formulas Ia and Ib as shown below:

Wherein within formula Ia, each integer n is 1, each R ₃ is sulfur, and each R ₄ is a C5 to C15 alkyl group, preferably a C8 to C12 alkyl group, and

Wherein within formula Ib, one integer n is 1, the associated R ₄ group is a C5 to C15 alkyl group (preferably a C8 to C12 alkyl group), and the associated R ₃ group is sulfur, and the other integer n is 0, the associated R ₃ group is hydrogen. In some embodiments, the thiadiazole or derivative thereof comprises a blend of formulas Ia and Ib, wherein formula Ia is the majority of the blend, and in other methods, the blend of Ia and Ib is from about 75 to about 90 weight percent Ia and from about 10 to about 25 weight percent Ib (or other ranges therebetween). In another method, the thiadiazole is a2, 5-dimercapto 1,3, 4-thiadiazole comprising 2, 5-bis- (nonyldisulfide) -1,3, 4-thiadiazole (such as from about 75% to about 90%) and 2, 5-mono- (nonyldisulfide) -1,3, 4-thiadiazole (such as from about 10% to about 25%).

In other methods or embodiments, examples of thiadiazole compounds useful in the fluids herein include 2-mercapto-5-hydrocarbylthio-1, 3, 4-thiadiazole, 2-mercapto-5-hydrocarbyldithio-1, 3, 4-thiadiazole, 2, 5-bis (hydrocarbylthio) -1,3, 4-thiadiazole, 2, 5-bis (hydrocarbyldithio) -1,3, 4-thiadiazole, variants thereof, or combinations thereof. 1,3, 4-thiadiazole is typically synthesized from hydrazine and carbon disulphide by known methods. See, for example, U.S. Pat. Nos. 2,765,289, 2,749,311, 2,760,933, 2,850,453, 2,910,439, 3,663,561, 3,862,798, 3,840,549, which are incorporated herein by reference.

Base oil

In one method, suitable base oils for the lubricating compositions or gear fluids herein include mineral oils, synthetic oils, and include all common mineral oil base stocks. The mineral oil may be a naphthenic oil or a paraffinic oil. Mineral oils may be refined by conventional methods using acids, bases and clays or other agents such as aluminum chloride, or may be extracted oils, for example produced by solvent extraction with solvents such as phenol, sulfur dioxide, furfural or dichlorodiethyl ether. The mineral oil may be hydrotreated or hydrofinished, dewaxed by a cooling or catalytic dewaxing process, or hydrocracked, such as from SK Innovation co., ltd (kouol, korea))A series of hydrocracked base oils. Mineral oils may be produced from natural crude sources or consist of isomerized wax material or other residues of refining processes.

The base oil used in the compositions herein or the base oil of lubricating viscosity may be selected from any suitable base oil for transmission or gear oil applications. Examples include base oils in class I-V as specified in the American Petroleum Institute (API) base oil interchangeability guidelines (American Petroleum Institute (API) Base Oil Interchangeability Guidelines). These three types of base oils are as follows:

TABLE 1 base oil types

Class I, class II and class III are mineral oil processing feedstocks that may be preferred for use in the transmission system or gear fluids of the present application. It should be noted that while group III base oils are derived from mineral oils, the rigorous processing that these fluids undergo results in their physical properties very similar to some real synthetic oils, such as PAO. Thus, oils derived from group III base oils may be referred to in the industry as synthetic fluids. Suitable oils may be derived from hydrocracked, hydrogenated, hydrofinished, unrefined, refined and rerefined oils, and mixtures thereof. In some methods, the base oil may be a blend of group I and group II oils, and the blend may be about 0% to about 100% of a group I oil, about 0% to about 100% of a group II oil, about 0% to about 100% of a group III oil, or various blends of group I and group II, group I and group III, or a blend of group II and group III oils.

Unrefined oils are those derived from natural, mineral or synthetic sources with little or no further purification treatment. Refined oils are similar to unrefined oils except they have been treated in one or more purification steps, which may result in an improvement in one or more properties. Examples of suitable purification techniques are solvent extraction, secondary distillation, acid or base extraction, filtration, diafiltration, etc. Oils refined to edible quality may or may not be useful. Edible oils may also be referred to as white oils. In some embodiments, the lubricating oil composition is free of edible oil or white oil.

Rerefined oils are also known as reclaimed or reprocessed oils. These oils are obtained using the same or similar processes as the refined oils. Typically these oils are further processed by techniques directed to the removal of spent additives and oil breakdown products.

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

The quantity of base oil included in the gear fluids herein may be selected from the group consisting of group I, group II, group III, and combinations of two or more of the foregoing, and wherein the quantity of base oil is not the base oil resulting from the provision of an additive component or viscosity index improver in the composition. In another embodiment, the quantity of base oil included in the lubricating composition may be selected from the group consisting of group I, group II, and combinations of two or more of the foregoing, and wherein the quantity of base oil is not the base oil resulting from the provision of an additive component or viscosity index improver in the composition.

The base oil may also be any synthetic base oil. Useful synthetic lubricating oils may include hydrocarbon oils such as polymerized, oligomeric or copolymerized olefins (e.g., polybutene, polypropylene, propylene isobutylene copolymers), poly (1-hexene), poly (1-octene), terpolymers or oligomers of 1-decene, such as poly (1-decene), such materials commonly referred to as alpha-olefins, and mixtures thereof, alkyl-benzenes (e.g., dodecylbenzene, tetradecylbenzene, dinonylbenzene, di- (2-ethylhexyl) -benzene), polyphenyls (e.g., diphenyl, terphenyl, alkylated polyphenyls), diphenylalkanes, alkylated diphenyl ethers and alkylated diphenyl sulfides and derivatives, analogs and homologs thereof or mixtures thereof. Polyalphaolefins are typically hydrogenated materials.

Other synthetic lubricating oils include polyol esters, diesters, liquid esters of phosphorus acid (e.g., toluene phosphate, trioctyl phosphate, and diethyl ester of decane phosphonic acid) or polytetrahydrofuran. The synthetic oil may be produced by a Fischer-Tropsch reaction (Fischer-Tropsch reaction) and may typically be hydroisomerised Fischer-Tropsch hydrocarbons or waxes. In one embodiment, the oil may be prepared by a Fischer-Tropsch gas-liquid synthesis procedure, as well as other gas-liquid oils.

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

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

Suitable transmission systems or gear lubricant compositions herein may include additive components in the ranges listed in table 2 below.

TABLE 2 suitable and preferred driveline or gear fluid compositions

The percentages of each of the above components represent weight percentages of each component, based on the weight of the total final additive or lubricating oil composition. The remainder of the lubricating oil composition is comprised of one or more base oils or solvents. The additives used to formulate the compositions described herein may be blended into the base oil or solvent, either alone or in various sub-combinations. However, it may be suitable to blend all components simultaneously using an additive concentrate (i.e., an additive plus diluent, such as a hydrocarbon solvent).

The lubricating compositions described herein can be formulated to provide lubrication, enhanced friction properties, and improved copper corrosion for a variety of applications. The driveline lubricating composition herein may be used for lubricating machine parts such as gears. Lubricating fluids according to the present disclosure may be used in gear applications such as industrial gear applications, automotive gear applications, axles, and stationary gearboxes. Gear types may include, but are not limited to, spur gears, helical gears, worm gears, rack gears, involute gears, bevel gears, helical gears, planetary gears, and hypoid gears, as well as limited slip applications and differentials. The driveline lubricating composition disclosed herein is also suitable for use in automatic or manual transmissions, including step-variable automatic transmissions, continuously variable transmissions, semi-automatic transmissions, automatic manual transmissions, toroidal transmissions and dual clutch transmissions. The driveline lubricating compositions herein are particularly useful for axles, transfer cases, differentials, such as straight differentials, steering differentials, limited slip differentials, clutch-type differentials, locking differentials, and the like.

Optional additives

In other methods, lubricants comprising such additives described above may also comprise one or more optional components, provided that such components and amounts thereof do not affect the performance characteristics as described in the preceding paragraphs. These optional components are described in the following paragraphs.

Other phosphorus-containing compounds

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

The one or more phosphorus-containing compounds may include ashless phosphorus-containing compounds. Examples of suitable phosphorus-containing compounds include, but are not limited to, thiophosphates, dithiophosphates, phosphates, phosphate esters, phosphites, phosphonates, phosphorus-containing carboxylic acid esters, ethers or amide salts thereof and mixtures thereof. Phosphorus-containing antiwear agents are more fully described in European patent 0612839.

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

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

The addition of a phosphorus-containing compound in combination with the above-described dispersant to a lubricant composition unexpectedly imparts positive friction characteristics, such as a low coefficient of friction, to the lubricant composition. In some cases, the effect of the present invention is even more pronounced where the phosphorus-containing compound itself imparts negative friction characteristics to the fluid. When these relatively poor friction reducing phosphorus containing compounds are combined with the olefin copolymer dispersants described herein, the lubricant compositions have an improved, i.e., lower coefficient of friction. That is, the dispersants herein tend to convert fluids comprising phosphorus-containing compounds having relatively poor coefficients of friction to fluids having improved friction properties.

This improvement in the friction characteristics of a lubricating composition containing the phosphorus-containing compound and olefin copolymer dispersant described herein is surprising because the friction performance of the fluid is superior to the combination of phosphorus-containing compounds with other types of dispersants, including polyisobutylene succinimide dispersants and olefin copolymer succinimide dispersants that do not have the specified characteristics of the copolymers described above.

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

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

The ashless phosphorus-containing compound may have the formula:

Wherein R1 of formula XIV is S OR O; R2 is-OR, -OH OR-R "; R3 is-OR", -OH OR SR "" 'C (O) OH, R4 is-OR ", -R'" is a C1 to C3 branched OR straight alkyl chain, and R "is a C1 to C18 hydrocarbyl chain. When the phosphorus-containing compound has the structure shown in formula XIV, the compound may have about 8 to about 16 weight percent phosphorus.

In some embodiments, the lubricant composition comprises a phosphorus-containing compound of formula XIV, wherein R1 is S; R2 is-OR "-, R3 is S R '" COOH, R4 is-OR "-, R'" is a C3 branched alkyl chain, R "is C4, and wherein the phosphorus-containing compound is present in an amount to deliver 80ppm to 900ppm of phosphorus to the lubricant composition.

In another embodiment, the lubricant composition comprises a phosphorus-containing compound of formula XIV, wherein R1 is O; R2 is-OH; R3 is-OR' OR-OH; R4 is-OR "-, R" is C5, and wherein the phosphorus-containing compound is present in an amount to deliver 80ppm to 1500ppm of phosphorus to the lubricant composition.

In further embodiments, the lubricant composition comprises a phosphorus-containing compound of formula XIV, wherein R1 is O, R2 is OR ', R3 is H, R4 is-OR ', R ' is C4, and wherein the one OR more phosphorus-containing compounds are present in an amount that delivers 80ppm to 1550ppm of phosphorus to the lubricant composition.

In other embodiments, the lubricant composition comprises a phosphorus-containing compound of formula XIV, wherein R1 is O; R2 is-R '; R3 is-OCH 3 or-OH, R4 is-OCH 3, R' is C18, and wherein one or more phosphorus-containing compounds are present in an amount that delivers 80ppm to 850ppm of phosphorus to the lubricant composition.

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

Other antiwear agents

The lubricant composition may also contain other antiwear agents that are phosphorus-free compounds. Examples of such antiwear agents include borates, borate epoxides, thiocarbamate compounds (including thiocarbamates, alkylene-coupled thiocarbamates and bis (S-alkyl dithiocarbamoyl) disulfides, thiocarbamate amides, thiocarbamate ethers, alkylene-coupled thiocarbamates and bis (S-alkyl dithiocarbamoyl) disulfides and mixtures thereof), sulfurized olefins, tridecyl adipates, titanium compounds and long chain derivatives of hydroxycarboxylic acids such as tartrate derivatives, tartaric acid amides, tartaric acid imides, citrates and mixtures thereof. Suitable thiocarbamate compounds the product is molybdenum dithiocarbamate. Suitable tartrate derivatives or tartrimides may contain alkyl ester groups, wherein the total number of carbon atoms on the alkyl groups may be at least 8. The tartrate derivative or tartrimide may contain alkyl ester groups, wherein the total number of carbon atoms on the alkyl groups may be at least 8. In one embodiment, the antiwear agent may comprise a citrate ester. The additional antiwear agent may be present in a range including from about 0 wt.% to about 15 wt.%, or from about 0.01 wt.% to about 10 wt.%, or from about 0.05 wt.% to about 5 wt.%, or from about 0.1 wt.% to about 3 wt.% of the lubricating oil composition.

Other extreme pressure agents

The lubricant compositions of the present disclosure may also contain other extreme pressure agents as long as the lubricating compositions herein include the noted amounts and distributions described herein. The optional extreme pressure agent may contain sulfur and may contain at least 12 wt.% sulfur. In some embodiments, the extreme pressure agent added to the lubricating oil is sufficient to provide at least 350ppm sulfur, 500ppm sulfur, 760ppm sulfur, about 350ppm to about 2,000ppm sulfur, about 2,000ppm to about 30,000ppm sulfur, or about 2,000ppm to about 4,800ppm sulfur, or about 4,000ppm to about 25,000ppm sulfur to the lubricant composition.

A variety of sulfur-containing extreme pressure agents are suitable and include sulfurized animal or vegetable fats or oils, sulfurized animal or vegetable fatty acid esters, fully or partially esterified esters of trivalent or pentavalent acids of phosphorus, sulfurized olefins (see, e.g., U.S. Pat. nos. 2,995,569;3,673,090;3,703,504;3,703,505;3,796,661;3,873,454 4,119,549;4,119,550;4,147,640;4,191,659;4,240,958;4,344,854;4,472,306; and 4,711,736), dihydrocarbyl polysulfides (see, e.g., U.S. Pat. nos. 2,237,625;2,237,627;2,527,948;2,695,316;3,022,351;3,308,166;3,392,201;4,564,709; and uk 1,162,334), functionally substituted dihydrocarbyl polysulfides (see, e.g., U.S. Pat. No. 4,218,332), and polysulfide olefin products (see, e.g., U.S. Pat. No. 4,795,576). Other suitable examples include organic sulfur compounds selected from the group consisting of sulfurized olefins, sulfur-containing amino heterocyclic compounds, 5-dimercapto-1, 3, 4-thiadiazoles, polysulfides having a majority of S3 and S4 sulfides, sulfurized fatty acids, sulfurized branched olefins, organic polysulfides, and mixtures thereof.

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

One suitable class of extreme pressure agents are polysulfides consisting of one or more compounds of the formula Ra-Sx-Rb, where Ra and Rb are hydrocarbyl groups each of which may contain from 1 to 18 and in other methods from 3 to 18 carbon atoms, and x may be in the range of from 2 to 8, typically in the range of from 2 to 5, especially 3. In certain methods, x is an integer from 3 to 5, wherein about 30% to about 60% of x is an integer of 3 or 4. The hydrocarbyl groups may be of a wide variety of types, such as alkyl, cycloalkyl, alkenyl, aryl, or aralkyl. Tertiary alkyl polysulfides, such as di-t-butyl trisulfide, and mixtures comprising di-t-butyl trisulfide (e.g., mixtures consisting essentially or entirely of tri-, tetra-and penta-sulfides) may be used. Examples of other useful dihydrocarbyl polysulfides include dipentyl polysulfides, dinonyl polysulfides, dodecyl polysulfides, and dibenzyl polysulfides.

Another suitable class of extreme pressure agents are sulfurized isobutylene produced by reacting an olefin such as isobutylene with sulfur. The Sulfurized Isobutylene (SIB), particularly sulfurized polyisobutylene, typically has a sulfur content of about 10% to about 55%, desirably about 30% to about 50% by weight. A variety of other olefins or unsaturated hydrocarbons, such as isobutylene dimers or trimers, may be used to form the sulfurized olefin extreme pressure agent. Various processes for preparing sulfurized olefins have been disclosed in the prior art. See, for example, U.S. patent No. 3,471,404 to Myers, U.S. patent No. 4,204,969 to Papay et al, U.S. patent No. 4,954,274 to Zaweski et al, U.S. patent No. 4,966,720 to DeGonia et al, and U.S. patent No. 3,703,504 to Horodysky et al, each of which is incorporated herein by reference.

Methods for preparing sulfurized olefins, including those disclosed in the above-identified patents, generally include forming a material commonly referred to as an "adduct" in which an olefin is reacted with a sulfur halide, such as sulfur monochloride. The adduct is then reacted with a sulfur source to provide a sulfurized olefin. The quality of the sulfurized olefin is typically measured by various physical properties including, for example, viscosity, sulfur content, halogen content, and copper corrosion test weight loss. U.S. patent No. 4,966,720 relates to sulfurized olefins for use as extreme pressure additives in lubricating oils and to two-step reactions for their preparation.

Antioxidant agent

The lubricating oil compositions herein may also optionally contain one or more antioxidants. Antioxidant compounds are known and include, for example, phenoxide sulfide, sulfurized olefin, phosphosulfurized terpene, sulfurized ester, aromatic amine, alkylated diphenylamine (e.g., nonyldiphenylamine, dinonyldiphenylamine, octyldiphenylamine, dioctyldiphenylamine), phenyl-alpha-naphthylamine, alkylated phenyl-alpha-naphthylamine, hindered non-aromatic amines, phenol, hindered phenol, oil soluble molybdenum compounds, macromolecular antioxidants, or mixtures thereof. The antioxidant compounds may be used alone or in combination.

The hindered phenolic antioxidants may contain sec-butyl and/or tert-butyl groups as sterically hindered groups. The phenolic group may be further substituted with a hydrocarbyl group and/or a bridging group attached to the second aromatic group. Examples of suitable hindered phenol antioxidants include 2, 6-di-tert-butylphenol, 4-methyl-2, 6-di-tert-butylphenol, 4-ethyl-2, 6-di-tert-butylphenol, 4-propyl-2, 6-di-tert-butylphenol or 4-butyl-2, 6-di-tert-butylphenol, or 4-dodecyl-2, 6-di-tert-butylphenol. In one embodiment, the hindered phenol antioxidant may be an ester and may include, for example, those commercially available from BASFL-135 or an addition product derived from 2, 6-di-tert-butylphenol and an alkyl acrylate wherein the alkyl group may comprise from about 1 to about 18, or from about 2 to about 12, or from about 2 to about 8, or from about 2 to about 6, or about 4 carbon atoms. Another commercially available hindered phenol antioxidant may be an ester and may include those available from EarMic (Albemarle Corporation)4716。

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

Examples of suitable olefins that can be sulfided to form a sulfided olefin include propylene, butene, isobutylene, polyisobutylene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, or mixtures thereof. In one embodiment, hexadecene, heptadecene, octadecene, nonadecene, eicosene, or mixtures thereof, and dimers, trimers, and tetramers thereof are particularly suitable olefins. Alternatively, the olefin may be a Diels-alder adduct (Diels-Alder adduct) of a diene, such as 1, 3-butadiene, with an unsaturated ester, such as butyl acrylate.

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

The one or more antioxidants may be present in the range of about 0 wt.% to about 20 wt.%, or about 0.1 wt.% to about 10 wt.%, or about 1 wt.% to about 5 wt.% of the lubricating oil composition.

Dispersing agent

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

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

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

Viscosity index improver

The lubricant compositions herein may also optionally contain one or more viscosity index improvers. Suitable viscosity index improvers may comprise polyolefins, olefin copolymers, ethylene/propylene copolymers, polyisobutylene, hydrogenated styrene-isoprene polymers, styrene/maleate copolymers, hydrogenated styrene/butadiene copolymers, hydrogenated isoprene polymers, alpha-olefin maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkylstyrenes, hydrogenated alkenyl aryl conjugated diene copolymers, or mixtures thereof. Other viscosity index improvers may include star polymers, and suitable examples are described in U.S. publication No. 20120101017A1, which is incorporated herein by reference.

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

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

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

Other optional additives

Other additives may be selected to perform one or more functions desired for the lubricant composition. In addition, one or more of the mentioned additives may be multifunctional and provide functionality other than or different from the functionality specified herein. The other additives may be additives other than the specified additives of the present disclosure and/or may include one or more of metal deactivators, viscosity index improvers, ashless TBN accelerators, antiwear agents, corrosion inhibitors, rust inhibitors, dispersants, dispersant viscosity index improvers, extreme pressure agents, antioxidants, foam inhibitors, demulsifiers, emulsifiers, pour point depressants, seal swelling agents, and mixtures thereof. Typically, a fully formulated lubricating oil will contain one or more of these additives.

Suitable metal deactivators may include derivatives of benzotriazole (typically tolyltriazole), dimercaptothiadiazole derivatives, 1,2, 4-triazole, benzimidazole, 2-alkyldithiobenzimidazole or 2-alkyldithiobenzothiazole, foam inhibitors including copolymers of ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate, demulsifiers including trialkyl phosphates, polyethylene glycol, polyethylene oxide, polypropylene oxide and (ethylene oxide-propylene oxide) polymers, pour point depressants including esters of maleic anhydride-styrene, polymethacrylates, polyacrylates or polyacrylamides.

Suitable foam inhibitors include silicon-based compounds such as siloxanes.

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

Suitable rust inhibitors may be single compounds or mixtures of compounds having the property of inhibiting corrosion of the ferrous metal surface. Non-limiting examples of rust inhibitors useful herein include oil-soluble high molecular weight organic acids such as 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, behenic acid, and cerotic acid, and oil-soluble polycarboxylic acids including dimer and trimer acids such as those produced from terpineol fatty acid, oleic acid, and linoleic acid. Other suitable corrosion inhibitors include long chain alpha, omega-dicarboxylic acids having a molecular weight in the range of about 600 to about 3000, and alkenyl succinic acids in which the alkenyl group contains about 10 or more carbon atoms, such as tetrapropenyl succinic acid, tetradecenyl succinic acid, and hexadecenyl succinic acid. Another useful type of acidic corrosion inhibitor is a half ester of alkenyl succinic acid having from about 8 to about 24 carbon atoms in the alkenyl group with an alcohol, such as polyethylene glycol. Corresponding semi-amides of such alkenyl succinic acids are also useful. Useful rust inhibitors are high molecular weight organic acids. In some embodiments, the engine oil is free of rust inhibitors.

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

The lubricant composition may also include a corrosion inhibitor (note that some of the other mentioned components may also have copper corrosion inhibiting properties). Suitable copper corrosion inhibitors include etheramines, polyethoxylated compounds such as ethoxylated amines and alcohols, imidazolines, mono-and dialkyl thiadiazoles, and the like.

Thiazole, triazole and thiadiazole are also useful in lubricants. Examples include benzotriazole, tolyltriazole, octyltriazole, decyltriazole, dodecyltriazole, 2-mercaptobenzotriazole, 2, 5-dimercapto-1, 3, 4-thiadiazole, 2-mercapto-5-hydrocarbylthio-1, 3, 4-thiadiazole, and 2-mercapto-5-hydrocarbyldithio-1, 3, 4-thiadiazole. In one embodiment, the lubricant composition comprises a 1,3, 4-thiadiazole, such as a 2-hydrocarbyl dithio-5-mercapto-1, 3, 4-dithiadiazole.

Defoamers/surfactants may also be included in the fluid according to the present invention. Various reagents are known for this purpose. Copolymers of ethyl acrylate and hexyl acrylate may be used, such as PC-1244 available from the company nux-vomica (Solutia). In other embodiments, silicone fluids, such as 4% DCF, may be included. Mixtures of defoamers may also be present in the lubricant composition.

As used herein, the terms "gear oil," "gear fluid," "gear lubricant," "base gear lubricant," "lubricating oil," "lubricant composition," "lubricating composition," "lubricant," and "lubricating fluid" refer to a finished lubricating product comprising a major amount of a base oil as discussed herein plus a minor amount of an additive composition as discussed herein. Such gear fluids are used in extreme pressure conditions, such as in transmissions and gear drive components having metal-to-metal contact conditions, for example in transmissions and/or limited slip differentials and/or wet brakes and/or wet clutches.

As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense, as is well known to those skilled in the art. In particular, it refers to a group having a carbon atom directly attached to the rest of the molecule and having predominantly hydrocarbon character. Each hydrocarbyl group is independently selected from the group consisting of hydrocarbon substituents and substituted hydrocarbon substituents containing one or more halogen groups, hydroxyl groups, alkoxy groups, mercapto groups, nitro groups, nitroso groups, amino groups, pyridyl groups, furyl groups, imidazolyl groups, oxygen, and nitrogen, and wherein no more than two non-hydrocarbon substituents are present for every ten carbon atoms in the hydrocarbyl group.

As used herein, unless explicitly stated otherwise, the term "weight percent" or "wt%" means the percentage of the component by weight of the entire composition. All percentages herein are by weight unless otherwise indicated.

The terms "soluble", "oil-soluble" or "dispersible" as used herein may, but do not necessarily, indicate that the compound or additive is soluble, miscible or capable of being suspended in oil in all proportions. However, the foregoing terms do mean that they are, for example, soluble, suspendable, soluble or stably dispersible in oil to an extent sufficient to exert their intended effect in the environment in which the oil is employed. Furthermore, the additional incorporation of other additives may also allow for the incorporation of higher levels of specific additives, if desired.

As used herein, the term "alkyl" refers to straight, branched, cyclic, and/or substituted saturated chain moieties of from about 1 to about 200 carbon atoms. As used herein, the term "alkenyl" refers to straight, branched, cyclic, and/or substituted unsaturated chain moieties of from about 3 to about 30 carbon atoms. As used herein, the term "aryl" refers to mono-and polycyclic aromatic compounds that may include alkyl, alkenyl, alkylaryl, amino, hydroxyl, alkoxy, halogen substituents, and/or heteroatoms including, but not limited to, nitrogen and oxygen.

As used herein, molecular weight is determined by Gel Permeation Chromatography (GPC) using commercially available polystyrene standards (having Mn of about 180 to about 18,000 as a calibration reference). The molecular weight (Mn) of any of the embodiments herein can be measured using Gel Permeation Chromatography (GPC) instruments and the like available from Waters, and the data processed using software such as Waters Empower software. The GPC instrument can be equipped with a Waters separation module and a Waters refractive index detector (or similar optional device). GPC operating conditions may include guard columns, 4 Agilent PLgel columns (300X 7.5mm in length; 5 μ in particle size, and pore size rangeThe column temperature was about 40 ℃. Unstabilized HPLC grade Tetrahydrofuran (THF) can be used as the solvent at a flow rate of 1.0mL/min. GPC instruments may be calibrated with commercially available Polystyrene (PS) standards having narrow molecular weight distributions ranging from 500g/mol to 380,000 g/mol. For samples with a mass of less than 500g/mol, the calibration curve can be extrapolated. The samples and PS standards were soluble in THF and prepared at concentrations of 0.1 wt% to 0.5 wt% and used without filtration. GPC measurements are also described in U.S. Pat. No. 5,266,223, incorporated herein by reference. GPC methods additionally provide molecular weight distribution information, see, e.g., W.Yau, J.J.Kirkland, and D.D. Bly, "modern size exclusion chromatography (Modern Size Exclusion Liquid Chromatography)", john Wiley and Sons, new York,1979, also incorporated herein by reference.

As used herein, any sulfur moiety distribution, amount, or ratio of the organosulfur compound is determined using CNMR via a Bruker Avance-3hd 500mhz instrument equipped with a 5mm BBO Prodigy probe (or equivalent). The samples were dissolved in chloroform-D at about 3% weight/wt for ¹ H NMR one-dimensional (1D) and two-dimensional (2D) synucleus experiments, and at about 30% weight/wt for ¹³ C1D and 2D iso-experiments. Chloroform-d was used as chemical shift reference, d _H =7.27 and d _C =77.0 ppm, respectively. The experiment was performed at ambient temperature. For ¹³ C NMR experiments, ninety degree pulse width, 5×t1delay and gating ¹ H were used for decoupling, and direct observation 1D ¹ H and ¹³C-¹ H decoupling experiments were performed under quantitative conditions. In addition, a distortion-free enhanced polarization transfer (DEPT) experiment using the 135 degree pulse option was also obtained. The 2D experiments used for assisted structural allocation were homonuclear correlation spectroscopy (COSY), heteronuclear Single Quantum Coherence (HSQC) and Heteronuclear Multiple Bond Correlation (HMBC). All NMR data were obtained using Bruker Topspin.62 software from brueck (Bruker Inc of Billerica MA) of bir card, ma, and processed using standard parameters (or equivalent equipment/software) using ACD/Spectrus processor 2021.1.3 software from advanced chemical Development, inc.

It should be understood that throughout this disclosure, the terms "comprises," "comprising," "includes," "including," and the like are to be construed as open-ended, and include any element, step, or ingredient not explicitly listed. The phrase "consisting essentially of" is intended to include any of the explicitly listed elements, steps, or ingredients as well as any additional elements, steps, or ingredients that do not materially affect the basic and novel aspects of the invention. The present disclosure also contemplates that any composition described using the terms "comprising," "including," "containing," and "containing" are also to be construed as including the disclosure of the same composition "consisting essentially of, or" consisting of, its specifically listed components.

Examples

The following examples are illustrative of exemplary embodiments of the present disclosure. In these examples, and elsewhere in the present application, all ratios, parts, and percentages are by weight unless otherwise specified. These examples are intended to be presented for illustrative purposes only and are not intended to limit the scope of the application disclosed herein. Any reference herein to a standardized test method refers to a version of the test method that is publicly available at the time of this disclosure, unless apparent from the context of the test method's use in the specification, claims, or examples.

Example 1

An exemplary organic polysulfide reaction product can be prepared by charging a 300mL stainless steel autoclave with sulfur (67.2 g,1.92 gram atom) and 0.1mL n-butylamine (1.0 mmol). The autoclave was cooled in a dry ice isopropanol bath and bubbled with N2 (4 x 100 psi). Isobutene (58.8 g,1.05 mol) was condensed into the autoclave. The autoclave was sealed and heated to 140 ℃ at 550psi autogenous pressure for 26.5 hours. After standing overnight, the autoclave was vented to a caustic collector and the condenser was cooled in dry ice, then heated to 10 ℃ and bubbled with N2 for 0.5 hours.

Next, a 100mL round bottom flask equipped with an overhead stirrer and a reflux condenser was charged with sodium hydrosulfide (10.8 g,46% aqueous solution) and sodium hydroxide (12.0 g,50% aqueous solution) and the vulcanized product (20 g) prepared in example 3A. The solution was stirred vigorously and heated to 80 ℃ for 2 hours and 100 ℃ for 2 hours. After cooling, the solution was taken up in diethyl ether and poured into a separating funnel.

Two organosulfides reaction products were prepared in accordance with the above, with the amount of caustic (sodium hydroxide) being varied as needed to form each of the reaction products:

The first organosulfide reaction product A had about 15 wt% of a compound having a portion S ₂, about 82 wt% of a compound having a portion S ₃, about 3 wt% of a compound having a portion S ₄, and no compound having a portion S ₅ or a portion S ₆, and the reaction product A had a weight ratio of S ₃ to S ₄ of about 27.3:1. As described above, the sulfide distribution was determined by CNMR.

The second organosulfide reaction product B had about 15 wt.% of a compound having a moiety S ₂, about 59 wt.% of a compound having a moiety S ₃, about 24 wt.% of a compound having a moiety S ₄, about 3 wt.% of a compound having a moiety S ₅, and no compound having a moiety S ₆, and reaction product B had a weight ratio of S ₃ to S ₄ of about 2.5:1. As described above, the sulfide distribution was also determined by CNMR.

Example 2

The organosulfides reaction products a and B of example 1 were evaluated in the lubricating compositions of table 3 when combined with various phosphorus-containing components and amine compounds. The lubricating compositions of table 3 included about 0.13 wt.% thiadiazole or derivative thereof in addition to the additives described in the tables. The lubricating composition also includes the same amount of additive package including the same detergents, friction modifiers, viscosity modifiers, antioxidants, rust inhibitors, corrosion inhibitors, seal swell agents, and defoamers. All compositions evaluated also included the balance of base oil and/or processing oil required to achieve a target KV100 viscosity of about 13cSt to 14 cSt.

The second phosphorus-containing component of Table 3 is an amine salt of dibutyl hydrothiophosphite. The third phosphorus-containing component of Table 3 is a phosphorus reaction product formed by (i) reacting O, O-bis (4-methyl-2-pentyl) dithiophosphoric acid with propylene oxide to form a first reaction product, (ii) reacting the first reaction product with phosphorus pentoxide to produce an acid phosphate intermediate, and (iii) neutralizing at least a majority of the intermediate with a C11 to C14 tertiary alkyl primary amine. The hydrocarbyl amine compound is an aliphatic tertiary primary amine.

TABLE 3 Table 3

* The amount of sulfur was calculated from each component.

* Sulfur distribution as determined by C NMR reflects the tert-butyl isomer, but other isomers present will have similar distributions and ratios.

* Combined amount of amine compound provided by the second and third phosphorus-containing components

Copper corrosion was evaluated using ASTM D130, with performance being 1A or 1B visual observations (121 ℃ for 3 hours) as described in the test methods. The test results are provided in table 4 below.

TABLE 4 Table 4

* Pass performance is 1A or 1B

Only the lubricating composition of fluid 1 of the present invention having a unique mixture of sulfur compounds provided by both of the organosulfides reaction products a and B passed both the extreme pressure test and the copper corrosion test when equilibrated with the three phosphorus-containing components and the additional hydrocarbyl amine compound that also maintained the methyl octadecylphosphonate in solution.

It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless expressly and unequivocally limited to one referent. Thus, for example, reference to "an antioxidant" includes two or more different antioxidants. As used herein, the term "include" and grammatical variants thereof are intended to be non-limiting such that recitation of items in a list is not to the exclusion of other like items that may be substituted or added to the listed items.

For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions used in the specification and claims, and other numerical values, are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

It is to be understood that each component, compound, substituent, or parameter disclosed herein is to be interpreted as being disclosed for use alone or in combination with one or more of each of the other components, compounds, substituents, or parameters disclosed herein.

It is further understood that each range disclosed herein is to be interpreted as having the same numerical value of each specific value within the range disclosed. Thus, for example, a range of 1 to 4 should be interpreted as an explicit disclosure of the values 1,2,3, and 4, and any range of such values.

It is further understood that each lower limit of each range disclosed herein is to be interpreted as being combined with each upper limit of each range and each specific value within each range disclosed herein for the same component, compound, substituent, or parameter. Accordingly, this disclosure should be construed as a disclosure of all ranges derived by combining each lower limit of each range with each upper limit of each range or with each specific value within each range, or by combining each upper limit of each range with each specific value within each range. That is, it should be further understood that any range between the endpoints within the broad ranges is also discussed herein. Thus, a range of 1 to 4 also means a range of 1 to 3, 1 to 2, 2 to 4, 2 to 3, etc.

Furthermore, a particular amount/value of a component, compound, substituent, or parameter disclosed in this specification or example should be construed as a disclosure of a lower limit or upper limit of a range, and thus may be combined with any other lower limit or upper limit or particular amount/value of a range for the same component, compound, substituent, or parameter disclosed elsewhere in this disclosure to form that range of component, compound, substituent, or parameter.

Although particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may not be presently contemplated may be appreciated by the applicant or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims (15)

1. A lubricating composition comprising: one or more base oils of lubricating viscosity; an extreme pressure agent, said extreme pressure agent contributing greater than 1.5 wt. % and no more than 3 wt. % sulfur; a first phosphorus-containing component comprising a hydrocarbyl phosphonic acid monoester; a second phosphorus-containing component comprising an amine salt of a dialkyl dithiophosphite; and a third phosphorus-containing component prepared by reacting a dialkyl dithiophosphoric acid with ethylene oxide and/or propylene oxide to provide a first reaction product, further reacting the first reaction product with phosphorus pentoxide to provide a second reaction product, and neutralizing the second reaction product with one or more primary aliphatic amines to provide the third phosphorus-containing component; Thiadiazole or a derivative thereof, wherein the thiadiazole or a derivative thereof is selected from a monoalkylthiol-substituted thiadiazole, a dialkylthiol-substituted thiadiazole, or a combination thereof; a hydrocarbyl amine compound, but less than about 0.1% by weight of said hydrocarbyl amine compound; wherein the lubricating composition comprises from about 0.1 wt. % to about 0.5 wt. % of the total amine compound provided by the second phosphorus-containing component, the third phosphorus-containing component, and the hydrocarbyl amine compound; and wherein about 15 weight % to about 25 weight % of the total amine compounds are provided by the hydrocarbyl amine compound, greater than 50 weight % of the total amine compounds are provided by the second phosphorus-containing component, and about 20 weight % to about 30 weight % of the total amine compounds are provided by the third phosphorus-containing component. 2 . The lubricating composition according to claim 1 , wherein the first reaction product is prepared by reacting O,O′-di(4-methyl-2-pentyl)dithiophosphoric acid with ethylene oxide and/or propylene oxide. 3. The lubricating composition of claim 1, wherein the weight ratio of the hydrocarbyl phosphonic acid monoester to the total amine compounds is from about 0.7:1 to about 1.8:1. 4. The lubricating composition of claim 1 , wherein the lubricating composition comprises from about 1.3 wt % to about 3 wt % total sulfur, at least about 90 wt % of the total sulfur being provided by a blend of organosulfide compounds that provide the extreme pressure agent, wherein the blend has from about 10 wt % to about 15 wt % organosulfide compounds having an _S2 moiety, from about 60 wt % to about 70 wt % organosulfide compounds having an _S3 moiety, and from about 12 wt % to about 20 wt % organosulfide compounds having an _S4 moiety. 5. The lubricating composition of claim 4, wherein the blend of organosulfide compounds is provided by a first organosulfide reaction product and a second organosulfide reaction product. 6. The lubricating composition of claim 5, wherein the lubricating composition comprises from about 1.5 wt% to about 2.8 wt% of the first organosulfide reaction product and from about 1.5 wt% to about 2.8 wt% of the second organosulfide reaction product. 7. The lubricating composition of claim 5, wherein the lubricating composition comprises a weight ratio of the first organosulfide reaction product to the second organosulfide reaction product of about 0.8:1 to about 1:0.8. 8. The lubricating composition of claim 4, wherein each organosulfide compound in the blend independently has a structure of the formula _R1 - _Sx - _R2 , and wherein _R1 and _R2 are independently selected from propyl, isopropyl, butyl, isobutyl, tert-butyl, or combinations thereof, and x is an integer from 2 to 6. 9. The lubricating composition of claim 1, wherein the hydrocarbyl amine compound is a tertiary aliphatic primary amine having 4 to 20 carbon atoms in the alkyl group. 10. The lubricating composition of claim 1 , wherein the hydrocarbylamine compound is selected from one or more of the following: tert-butylamine, tert-hexyl primary amine, 1-methyl-1-amino-cyclohexane, tert-octyl primary amine, tert-decyl primary amine, tert-dodecyl primary amine, tert-tetradecyl primary amine, tert-hexadecyl primary amine, tert-octadecyl primary amine, tert-tetracosyl primary amine, tert-octacosyl primary amine, tert-oleyl amine, or a combination thereof. 11. The lubricating composition according to claim 1, wherein (a) the hydrocarbyl phosphonic acid monoester has a structure of formula II, wherein R ₅ is a C ₁₂ to C ₃₀ hydrocarbon group, R ₆ is a C1 to C4 alkyl group, and R' is hydrogen or an alkyl group, and/or (b) the lubricating composition comprises from about 0.1 wt. % to about 0.8 wt. % of the hydrocarbyl phosphonic acid monoester. 12. The lubricating composition of claim 1 , wherein (a) the thiadiazole is 1,3,4-thiadiazole or a derivative thereof; (b) the lubricating composition comprises about 1 wt % or less of the thiadiazole or derivative thereof; and/or (c) the thiadiazole or derivative thereof comprises one or more compounds having the structure of Formula I: in Each R ₃ is independently hydrogen or sulfur; Each R ₄ is independently an alkyl group; n is an integer of 0 or 1, and if R ₃ is hydrogen, then the integer n of the adjacent R ₄ moiety is 0, and if R ₃ is sulfur, then said n of said adjacent R ₄ moiety is 1; and wherein at least one R ₃ is sulfur. 13. The lubricating composition of claim 1, wherein the second phosphorus-containing component is an amine salt of dibutyl hydrogen thiophosphate. 14. The lubricating composition of claim 1, wherein the one or more primary aliphatic amines comprise a tertiary primary aliphatic amine. 15. A method of lubricating gears, differentials and/or wet brakes with the lubricating composition of claim 1, and wherein the lubricating composition is provided from a common fluid reservoir, tank and/or sump.