LUBRICATING COMPOSITION AND METHOD OF FORMATION RELATING THERETO

Info

Publication number: 20210301217
Type: Application
Filed: Mar 30, 2020
Publication Date: Sep 30, 2021
Inventors: Junya IWASAKI (Wixom, MI), Ryo YAMADA (Tokyo)
Application Number: 16/834,221

Abstract

The present disclosure provides a lubricating composition that includes one or more boron-containing compounds and method of forming the same. The lubricating composition includes one or more boron-containing compounds, one or more metal-based detergents, one or more amine-based antioxidants, one or more phenol-based antioxidants, and a base oil balance. The lubricating composition includes greater than or equal to about 60 ppm to less than or equal to about 300 ppm of boron atoms that define the one or more boron-containing compounds; greater than or equal to about 1,100 ppm of metal atoms that define the one or more metal-based detergents; greater than or equal to about 0.70 wt. % to less than or equal to about 2.00 wt. % of the one or more amine-based antioxidants; and greater than or equal to about 0.30 wt. % to less than or equal to about 2.00 wt. %, of the one or more phenol-based antioxidants.

Description

Description

FIELD

The present disclosure relates to lubricating compositions, for example engine lubricants or lubricating oils, such as for use with internal-combustion engines (e.g., sump-lubricating engine), and methods for forming such lubricating compositions.

BACKGROUND

This section provides background information related to the present disclosure and is not necessarily prior art.

Decomposition of refuse (e.g., municipal solid waste (“MSW”)) at landfills often produces gases, commonly referred to as landfill gas or gases. Most landfill gases are a natural byproduct of bacterial decomposition of organic material and include primarily methane and carbon dioxide. Landfill gases also frequently include other volatile organic compounds (“VOCs”), such as nitrogen, oxygen, ammonia, sulfides, hydrogens, carbon monoxide, and non-methane organic compounds, such as trichloroethylene, benzene, and vinyl chloride, as well as various other gases.

Landfill gases can be collected, for example using wells installed vertically and/or horizontally in the waste mass, and used in various ways, for example, landfills gases may be utilized directly by onsite boilers or any type of combustion system and electricity can be generated on site through the use of, for example, microturbines, steam turbines, or fuel cells. In the instance of engines that are configured to combust landfill gases, the acidic nature of the landfill gases (such as that resulting from the presence of hydrogen sulfate) and/or the presence of siloxanes may deteriorate engine oil, for example as the result of oxidation, which adversely affects detergency of engine oil and, in certain instances, lead elution from various engine components. Accordingly, it would be desirable to develop improved materials, for example engine oils and engine oil additives, and methods of making the same, for an internal-combustion engine (e.g., sump-lubricating engine) that decreases or prevents oxidation, detergency, and/or lead elution within the engine when landfill gases are used.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

In various aspects, the present disclosure provides a lubricating composition that includes one or more boron-containing compounds. The lubricating composition may include one or more boron-containing compounds, one or more metal-based detergents, one or more amine-based antioxidants, one or more phenol-based antioxidants, and a base oil balance. For example, the lubricating composition may include greater than or equal to about 60 ppm to less than or equal to about 300 ppm of boron atoms that define the one or more boron-containing compounds; greater than or equal to about 1,100 ppm of metal atoms that define the one or more metal-based detergents; greater than or equal to about 0.70 wt. % to less than or equal to about 2.00 wt. % of the one or more amine-based antioxidants; and greater than or equal to about 0.30 wt. % to less than or equal to about 2.00 wt. %, of the one or more phenol-based antioxidants.

In one aspect, a combined amount of the one or more amine-based antioxidants and the one or more phenol-based antioxidants may be greater than or equal to about 1.5 wt. %.

In one aspect, the lubricating composition may include greater than or equal to about 0.40 wt. % to less than or equal to about 6 wt. % of one or more boron-containing compounds.

In one aspect, the lubricating composition may include greater than or equal to about 0.10 wt. % to less than or equal to about 2.00 wt. % of one or more metal-based detergents.

In one aspect, the lubricating composition may include greater than or equal to about 1,200 ppm of metal atoms defining the one or more metal-based detergents.

In one aspect, the one or more boron-containing compounds may include borated succinimide.

In one aspect, the one or more metal detergents may include at least one of a calcium detergent and a magnesium detergent.

In one aspect, the lubricating composition may include greater than or equal to about 1000 ppm to less than or equal to about 1400 ppm of calcium atoms, and greater than or equal to about 100 ppm to less than or equal to about 400 ppm of magnesium atoms.

In one aspect, a mass ratio between nitrogen atoms (N) and metal atoms (M) in the lubricating oil (M/N) may be greater than or equal to about 1.0 to less than or equal to about 2.0.

In one aspect, the lubricating composition may further include greater than or equal to about 0.20 wt. % to less than or equal to about 0.75 wt. % of one or more anti-wear and/or extreme pressure agents.

In one aspect, the one or more anti-wear and/or extreme pressure agents may include zinc dialkyldithiophosphate (ZnDTP).

In one aspect, the lubricating composition further includes greater than 0 wt. % to less than or equal to about 3.0 wt. % of one or more viscosity index improvers.

In various other aspects, the present disclosure provides a method for forming a lubricating composition. The method includes adding to a base oil one or more boron-containing compounds such that the lubricating composition includes greater than or equal to about 60 ppm to less than or equal to about 300 ppm of boron atoms that define the one or more boron-containing compounds; adding to the base oil one or more metal-based detergents such that the lubricating composition includes greater than or equal to about 1,100 ppm of metal atoms that define the one or more metal-based detergents; adding to the base oil greater than or equal to about 0.70 wt. % to less than or equal to about 2.00 wt. % of one or more amine-based antioxidants; and adding to the base oil greater than or equal to about 0.30 wt. % to less than or equal to about 2.00 wt. %, of one or more phenol-based antioxidants.

In one aspect, a combined amount of the one or more amine-based antioxidants and the one or more phenol-based antioxidants may be greater than or equal to about 1.5 wt. %; an amount of the one or more boron-containing compounds added to the base oil may be greater than or equal to about 0.40 wt. % to less than or equal to about 6 wt. %; and an amount of the one or more metal-based detergents added to the base oil may be greater than or equal to about 0.10 wt. % to less than or equal to about 2.00 wt. %.

In one aspect, the one or more boron-containing compounds may include boron succinimide.

In one aspect, the one or more metal detergents include at least one of a calcium detergent and a magnesium detergent.

In one aspect, a mass ratio between nitrogen atoms (N) and metal atoms (M) in the lubricating oil (M/N) may be greater than or equal to about 1.0 to less than or equal to about 2.0.

In one aspect, the lubricating composition may further include greater than or equal to about 0.25 wt. % to less than or equal to about 0.75 wt. % of one or more anti-wear and/or extreme pressure agents.

In one aspect, the lubricating composition may further include greater than 0 wt. % to less than or equal to about 0.75 wt. % of one or more viscosity index improvers.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DETAILED DESCRIPTION

Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth, such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an”, and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises”, “comprising”, “including”, and “having”, are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being “on”, “engaged to”, “connected to”, or “coupled to” another element or layer, it may be directly on, engaged, connected, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on”, “directly engaged to”, “directly connected to”, or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between”, “adjacent” versus “directly adjacent”, etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer, or section from another region, layer, or section. Terms such as “first”, “second”, and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper”, and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The present disclosure relates to lubricating compositions, for example lubricating additives and lubricating oils. The lubricating compositions of this disclosure are useful in the instance of internal-combustion engines, in particular in internal-combusting engines using as a fuel source landfill gases and/or natural gas. When used in internal-combustion engines, the lubricating composition decreases or prevents oxidation, detergency, and/or lead elution within the system. Though the lubricating composition is described as applied to internal-combustion engines, the lubricating composition may be useful in other systems, especially those to be used or occurring in acidic environments and/or where oxidation occurs.

Lubricating Composition

In various aspects, the lubricating composition includes a base oil and one or more lubricating additives. The one or more lubricating additives may include, for example, dispersants, metal-based detergents, and/or antioxidants, such as amine-based antioxidants and phenol-based antioxidants. The lubricating oil may include greater than or equal to about 3 wt. % to less than or equal to about 15 wt. %, and in certain aspects, optionally greater than or equal to about 5 wt. % to less than or equal to about 10 wt. %, of the one or more lubricating additives and a balance of base oil.

Base Oil

The one or more lubricating additives in accordance with various aspects of the present disclosure may be added or applied to both base oils comprising mineral oil and base oils comprising synthetic oils, and in certain instances, the one or more lubricating additives may be added to base oils comprising a mixture of mineral and synthetic oils.

Example mineral oils include an atmospheric residue obtained by atmospheric distillation of a crude oil, such as a paraffinic mineral oil, an intermediate mineral oil, a naphthenic mineral oil, a distillate oil obtained by vacuum distillation of the atmospheric residue; and oils or waxes obtained by subjecting the distillate oil to at least one purification process, such as solvent deasphalting, solvent extraction, hydrofinishing, solvent dewaxing, catalytic dewaxing, isomerization dewaxing, vacuum distillation. In various aspects, mineral oils include Group 2 and/or Group 3 oils as defined by the American Petroleum Institute (“API”).

Examples of the synthetic oil include poly-α-olefins, such as polybutene and an α-olefin homopolymer or copolymer (for example, a homopolymer or copolymer of an α-olefin having a carbon number of 8 to 14, such as an ethylene-α-olefin copolymer); various esters, such as a polyol ester, a dibasic acid ester, and a phosphate ester; various ethers, such as a polyphenyl ether; a polyglycol; an alkyl benzene; an alkyl naphthalene; and synthetic oils obtained by isomerizing a wax (e.g., GTL wax) produced by a Fischer-Tropsch process or the like.

In various aspects, the base oil has a kinematic viscosity at 100° C. of greater than or equal to about 2.0 mm²/s to less than or equal to about 20.0 mm²/s, optionally greater than or equal to about 4.0 mm²/s to less than or equal to about 15.0 mm²/s, optionally greater than or equal to about 8.0 mm²/s to less than or equal to about 15.0 mm²/s, and in certain aspects, optionally greater than or equal to about 10.0 mm²/s to less than or equal to about 14.0 mm²/s. When the kinematic viscosity at about 100° C. is greater than or equal to about 2.0 mm²/s evaporation loss may be unsubstantial, and when the kinematic viscosity at about 100° C. is less than or equal to about 20.0 mm²/s power loss as a result of viscous resistance may be suppressed and a fuel consumption improving effect obtained.

Dispersant

Dispersants may be useful for maintaining or improving the solubility of oxidation byproducts and reducing or substantially eliminating deposition of precipitated byproducts, for example, on metal surfaces. In various aspects, the lubricating composition may include greater than or equal to about 0.40 wt. % to less than or equal to about 6 wt. %, and in certain aspects, optionally greater than or equal to about 2 wt. % to less than or equal to about 5.75 wt. %, of the one or more dispersants. Dispersants may be ashless or ash-forming in nature. For example, metal-containing dispersants are often ash-forming, while non-metal dispersants are often ashless dispersants that form little to no ash during combustion. Ashless dispersants include, for example, nitrogen-containing dispersants, such as succinimide dispersants.

In various aspects, the one or more lubricating additives may include a boron-containing compound. The boron-containing compound comprises at least one borated dispersant or a mixture of a borated dispersant and a non-borated dispersant. Preferably, the borated dispersant includes, for example, a borated succinimide, a borated succinate ester, a borated succinate ester amide, a borated Mannich base, and mixtures thereof. The non-borated dispersant includes, for example, a hydrocarbyl succinic anhydride derived succinimide or succinate ester with a coupling agent, wherein the coupling agent comprises a boron-containing compound. Preferably, boron is provided to the lubricating composition by a mixture of an organic or inorganic boron-containing compound and a borated succinimide and/or a boron-containing compound and a hydrocarbyl succinimide and/or a borated succinimide, a borated succinate ester, a borated succinate ester amide, a Mannich base, or mixtures thereof. The borated succinimide is preferably a mono succinimide, bissuccinimide, or a mixture thereof.

The lubricating composition may include an effective amount of boron of greater than or equal to about 60 ppm. As discussed in more detailed below, for example in the instance of comparable example three, effective amounts of boron greater than or equal to about 60 ppm may aid in the reduction or elimination of lead elution. In various aspects, the lubricating composition may include an effective amount of boron less than or equal to about 300 ppm, optionally less than or equal to about 250 ppm, and in certain aspects, optionally less than or equal to about 200 ppm. As discussed in more detail below, for example in the instance of example four, effective amounts of boron less than or equal to about 200 ppm may aid in the reduction or elimination of coking. The borated dispersant or boron-containing dispersant may include, in various instances, about 1.3 wt. % of boron and about 1.23 wt. % of nitrogen. An example of such a boron-containing compound is borated succinimide.

From the viewpoint of improving the detergency at a high temperature, the detergent dispersant may include an alkenylsuccinimide compound having, for example, a monoimide structure or a bisimide structure. For example, the alkenylsuccinimide compound may be selected from alkenylsuccinimide and boronated alkenylsuccinimide compounds. Examples of the alkenylsuccinimide may include alkenylsuccinimide monoimide represented by the following general formula (B3-1) and alkenylsuccinimide bisimide represented by the following general formula (B3-2). Examples of the boronated alkenylsuccinimide include a boronated compound of an alkenylsuccinimide represented by the following general formula (B3-1) or (B3-2), preferably include a boronated compound of an alkenylsuccinimide represented by the following general formula (B3-1).

In the general formulae (B3-1) and (B3-2), R^AA, R^A1, and R^A2are each independently an alkenyl group having a weight average molecular weight (MW) of 500 to 3,000 (preferably 1,000 to 3,000). Examples of the alkenyl group that may be selected as R^A, R^A1, and R^A2include a polybutenyl group, a polisobutenyl group, an ethylene-propylene copolymer, and the like. Of those, a polybutenyl group or a polyisobutenyl group is preferred. R^B, R^B1, and R^B2are each independently an alkylene group having a carbon number of 2 to 5, x1 is an integer of 1 to 10, preferably an integer of 2 to 5, and more preferably 3 or 4, x2 is an integer of 0 to 10, preferably an integer of 1 to 4, and more preferably 2 or 3

The alkenylsuccinimide can be, for example, produced by allowing an alkenylsuccinic anhydride that is obtained through a reaction of a polyolefin and maleic anhydride to react with a polyamine. Examples of the polyolefin include polymers that are obtained through polymerization of one or two or more selected from an α-olefin having a carbon number of 2 to 8, and a copolymer of isobutene and 1-butene is preferred. Examples of the polyamine include single diamines, such as ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, etc.; polyalkylenepolyamines, such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, di(methylethylene)triamine, dibutylenetriamine, tributylenetetramine, pentapentylenehexamine, etc.; piperazine derivatives, such as aminoethylpiperazine, etc.; and the like.

The boronated alkenylsuccinimide can be produced, for example, by allowing an alkenylsuccinic anhydride that is obtained through a reaction of the aforementioned polyolefin and maleic anhydride to react with the aforementioned polyamine and a boron compound. Examples of the boron compound include boron oxide, a boron halide, boric acid, boric anhydride, a boric acid ester, an ammonium salt of boric acid, and the like.

In various aspects, a ratio of the boron atom and the nitrogen atom constituting the boronated alkenylsuccinimide, [B/N] is preferably about 0.5 or more, more preferably about 0.6 or more, still more preferably about 0.8 or more, and yet still more preferably, about 0.9 or more.

The content of the alkenylsuccinimide compound (B3), including alkenylsuccinimide and boronated alkenylsuccinimide compounds, in terms of a nitrogen atom may be about 0.005 to 0.30 mass %, more preferably about 0.005 to 0.25mass %, still more preferably about 0.01 to 0.20 mass%, yet still more preferably about 0.01 to 0.10 mass %, even yet still more preferably about 0.01 to 0.08 mass %, even still more preferably about 0.01 to 0.06 mass %, even still more further preferably about 0.015 to 0.04 mass %, and especially preferably about 0.02 to 0.04 mass % on a basis of the total amount (100 mass %) of the lubricating composition. When the foregoing is about 0.01 mass % or more, a lubricating composition with more improved detergency at a high temperature can be provided. On the other hand, when the foregoing content is about 0.10 mass % or less, the kinematic viscosity of the lubricating composition is easily regulated low, and the fuel saving properties can be improved.

A ratio of the content (i) of the alkenyl succinimide in terms of a nitrogen atom and the content (ii) of the boronated alkenylsuccinimide in terms of a boron atom, [(i)/(ii)] is preferably about 0.5 to 3.5, more preferably about 0.5 to 3.0, still more preferably about 0.7 to 2.5, and yet still more preferably about 0.8 to 2.0. The content of the boronated alkenylsuccinimide included as the alkenylsuccinimide compound (B3) in terms of a boron atom is preferably about 0.001 to 0.15 mass %, more preferably about 0.001 to 0.10 mass %, still more preferably about 0.003 to 0.07 mass %, yet still more preferably about 0.005 to 0.04 mass %, and especially preferably about 0.008 to 0.03 mass % on a basis of the total amount (100 mass %) of the lubricating composition. The content of the boronated alkenylsuccinimide in terms of a nitrogen atom is preferably about 0.001 to 0.10 mass %, more preferably about 0.005 to 0.05 mass %, still more preferably about 0.005 to 0.04 mass %, and yet still more preferably about 0.008 to 0.03 mass % on a basis of the total amount (100 mass %) of the lubricating composition.

Metal-Based Detergent

Metal-based detergents may, in many instances, reduce or substantially neutralize oil impurities so as to reduce oil-induced deposits within the system using or circulating the lubricating oil. In various aspects, the lubricating composition may include greater than or equal to about 0.10 wt. % to less than or equal to about 2.00 wt. %, and in certain aspects, optionally greater than or equal to about 1.50 wt. % to less than or equal to about 1.80 wt. %, of the one or more metal-based detergents. More particularly, the lubricating composition may include an effective amount of metal atoms defining the one or more metal-based detergents of greater than or equal to about 1,100 ppm to less than or equal to about 1,800 ppm, optionally greater than or equal to about 1,200 ppm to less than or equal to about 1,700 ppm, optionally greater than or equal to about 1,350 ppm to less than or equal to about 1,600 ppm, and in certain aspects, optionally greater than or equal to about 1,400 ppm to less than or equal to about 1,600 ppm. Effective amounts of metal-based detergents of less than or equal to about 1,800 ppm may be effective to reduce or limit ash formation within the lubricating composition, while effective amounts of greater than or equal to about 1,100 ppm may be effective to improve detergency at a high temperature.

In various aspects, the one or more metal-based detergents include, for example, organic acid metal salt compounds comprising a metal atom selected from an alkali metal and an alkaline earth metal. Example alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium. Example alkaline earth metals include beryllium, magnesium, calcium, strontium, and barium. For example, in certain variations, the organic acid metal salt compounds include one or more or sodium, calcium, magnesium, and barium. In each instance, the one or more metal-based detergents may be basic or overbased salts having metallic detergency base numbers greater than or equal to about 10 mgKOH/g to less than or equal to less than or equal to about 600 mgKOH/g, and in certain aspects, optionally greater than or equal to about 20 mgKOH/g to less than or equal to less than or equal to about 500 mgKOH/g.

By way of non-limiting example, the one or more metal-based detergents may include one or more of a calcium detergent and magnesium detergent. For example, the one or more metal-based detergents may include a calcium-containing detergent and a magnesium-containing detergent. For example, the lubricating composition may include an effective amount of calcium atoms of greater than or equal to about 1,000 ppm to less than or equal to about 1,400 ppm, and in certain aspects, optionally greater than or equal to about 1,100 ppm to less than or equal to about 1,300 ppm; and an effective amount of magnesium atoms of greater than or equal to about 100 ppm to less than or equal to about 400 ppm, and in certain aspects, optionally greater than or equal to about 200 ppm to less than or equal to about 300 ppm.

Example calcium-containing detergents include, for example, overbased calcium salicylate (comprising about 8.0 wt. % of calcium and having a base value of about 225 mgKOH/g), neutral calcium sulfonate (comprising about 2.6 wt. % of calcium and having a base value of about 27.5 mgKOH/g), and calcium sulfonate (comprising about 11.6 wt. % of calcium and having a base value of about 300 mgKOH/g). Calcium salicylate, for example, may be effective to improve detergency at high temperatures and/or in reducing or preventing oxidation. Example magnesium-containing detergents include, for example, overbased magnesium sulfonate (comprising about 9.1 wt. % of magnesium and having a base value of about 405 mgKOH/g). Calcium or magnesium sulfonate, for example, may be effect to improve detergency at low temperatures.

In further variations, useful detergents include, for example, alkaline earth metal detergents, or mixtures of alkaline earth metal detergents. A typical alkaline earth metal detergent is an anionic material that contains a long chain hydrophobic portion of the molecule and a smaller anionic or oleophobic hydrophilic portion of the molecule. The anionic portion of the detergent is derived from an organic acid such as a sulfur acid, carboxylic acid, phosphorous acid, phenol, or mixtures thereof. The counter ion is an alkaline earth metal. Preferably, the detergent comprises at least one alkaline earth metal salt of an organic acid, and the at least one alkaline earth metal salt of an organic acid comprises at least one magnesium salt of an organic acid.

Preferred detergents useful in the lubricating compositions are selected from the group consisting of an alkaline earth metal sulfonate, an alkaline earth metal carboxylate (e.g., salicylate), an alkaline earth metal phenate, an alkaline earth metal phosphate, and mixtures thereof. The alkaline earth metal sulfonate, alkaline earth metal carboxylate, alkaline earth metal phenate, alkaline earth metal phosphate, and mixtures thereof, and the amount of the alkaline earth metal sulfonate, alkaline earth metal carboxylate, alkaline earth metal phenate, alkaline earth metal phosphate, and mixtures thereof in the lubricating oil, are sufficient for the engine to exhibit reduced low speed pre-ignition, as compared to low speed pre-ignition performance achieved in an engine using a lubricating oil containing a detergent other than the alkaline earth metal sulfonate, alkaline earth metal carboxylate, alkaline earth metal phenate, alkaline earth metal phosphate, and mixtures thereof, and in an amount other than the amount of the alkaline earth metal sulfonate, alkaline earth metal carboxylate, alkaline earth metal phenate, alkaline earth metal phosphate, and mixtures thereof, in the lubricating oil.

Alkaline earth metal sulfonates are a preferred class of detergents. Sulfur acids useful in preparing the alkaline earth metal sulfonates include, for example, sulfonic acids, thiosulfonic, sulfinic, sulfenic, partial ester sulfuric, sulfurous and thiosulfuric acids. Sulfonic acids are preferred. The sulfonic acids are generally petroleum sulfonic acids or synthetically prepared alkaryl sulfonic acids. Among the petroleum sulfonic acids, the most useful products are those prepared by the sulfonation of suitable petroleum fractions with a subsequent removal of acid sludge, and purification. Synthetic alkaryl sulfonic acids are prepared usually from alkylated benzenes such as the Friedel-Crafts reaction products of benzene and polymers such as tetrapropylene. The following are specific examples of sulfonic acids useful in preparing the alkaline earth metal sulfonate detergents useful in this disclosure. It is to be understood that such examples serve also to illustrate the alkaline earth metal salts of such sulfonic acids. In other words, for every sulfonic acid enumerated, it is intended that the corresponding basic alkaline earth metal salts thereof are also understood to be illustrated.

Such sulfonic acids include mahogany sulfonic acids, bright stock sulfonic acids, petrolatum sulfonic acids, mono- and polywax-substituted naphthalene sulfonic acids, cetylchlorobenzene sulfonic acids, cetylphenol sulfonic acids, cetylphenol disulfide sulfonic acids, cetoxycapryl benzene sulfonic acids, dicetyl thianthrene sulfonic acids, dilauryl beta-naphthol sulfonic acids, dicapryl nitronaphthalene sulfonic acids, saturated paraffin wax sulfonic acids, unsaturated paraffin wax sulfonic acids, hydroxy-substituted paraffin wax sulfonic acids, tetra-isobutylene sulfonic acids, tetra-amylene sulfonic acids, chloro-substituted paraffin wax sulfonic acids, nitroso-substituted paraffin wax sulfonic acids, petroleum naphthene sulfonic acids, cetylcyclopentyl sulfonic acids, lauryl cyclohexyl sulfonic acids, mono- and polywax-substituted cyclohexyl sulfonic acids, dodecylbenzene sulfonic acids, “dimer alkylate” sulfonic acids, and the like.

Alkyl-substituted benzene sulfonic acids wherein the alkyl group contains at least eight carbon atoms including dodecyl benzene “bottoms” sulfonic acids are useful in this disclosure. The latter are acids derived from benzene, which has been alkylated with propylene tetramers or isobutene trimers to introduce 1, 2, 3, or more branched-chain C12 substituents on the benzene ring. Dodecyl benzene bottoms, principally mixtures of mono- and di-dodecyl benzenes, are available as by-products from the manufacture of household detergents.

Preferred alkaline earth metal sulfonates include magnesium sulfonate, calcium sulfonate, and mixtures thereof.

Alkaline earth phenates are a useful class of detergents. These detergents can be made by reacting alkaline earth metal hydroxide or oxide (CaO, Ca(OH)2, BaO, Ba(OH)2, MgO, Mg(OH)2, for example) with an alkyl phenol or sulfurized alkylphenol. Useful alkyl groups include straight chain or branched C1-C30 alkyl groups, preferably, C4-C20 or mixtures thereof. Examples of suitable phenols include isobutylphenol, 2-ethylhexylphenol, nonylphenol, dodecyl phenol, and the like. It should be noted that starting alkylphenols may contain more than one alkyl substituent that are each independently straight chain or branched and can be used from 0.5 to 6 weight percent. When a non-sulfurized alkylphenol is used, the sulfurized product may be obtained by methods well known in the art. These methods include heating a mixture of alkylphenol and sulfurizing agent (including elemental sulfur, sulfur halides such as sulfur dichloride, and the like) and then reacting the sulfurized phenol with an alkaline earth metal base.

Preferred phenate compounds include, for example, magnesium phenate, calcium phenate, an overbased phenate compound, a sulfurized/carbonated calcium phenate compound and mixtures thereof.

Alkaline earth metal salts of carboxylic acids are also useful as detergents. These carboxylic acid detergents may be prepared by reacting a basic alkaline earth metal compound with at least one carboxylic acid and removing free water from the reaction product. These compounds may be overbased to produce the desired TBN level.

Detergents made from salicylic acid are one preferred class of detergents derived from carboxylic acids. Useful salicylates include long chain alkyl salicylates. One useful family of compositions is of the formula 2 where R is an alkyl group having 1 to about 30 carbon atoms, n is an integer from 1 to 4, and M is an alkaline earth metal. Preferred R groups are alkyl chains of at least C11, preferably C13 or greater. R may be optionally substituted with substituents that do not interfere with the detergent's function. M is preferably, calcium, magnesium, or barium. More preferably, M is calcium or magnesium.

Hydrocarbyl-substituted salicylic acids may be prepared from phenols by the Kolbe reaction (see U.S. Pat. No. 3, 595,791). The alkaline earth metal salts of the hydrocarbyl-substituted salicylic acids may be prepared by double decomposition of an alkaline earth metal salt in a polar solvent such as water or alcohol.

Preferred carboxylate compounds comprise a noncarbonated magnesium salicylate (carboxylate); a carbonated magnesium salicylate (carboxylate); a noncarbonated calcium salicylate (carboxylate); a carbonated calcium salicylate (carboxylate); and mixtures thereof.

Salts that contain a substantially stoichiometric amount of the alkaline earth metal are described as neutral salts and have a total base number (TBN, as measured by ASTM D2896) of from about 0 to 100 mgKOH/g. Many compositions are overbased, containing large amounts of a metal base that is achieved by reacting an excess of an alkaline earth metal compound with an acidic gas (such as carbon dioxide). Useful detergents can be neutral, mildly overbased, or highly over-based. These detergents can be used in mixtures of neutral, overbased, highly overbased magnesium salicylate, sulfonates, phenates and/or calcium salicylate, sulfonates, and phenates. The TBN ranges can vary from low TBN of about 0 to 100 mgKOH/g, medium TBN of about 100 to 200 mgKOH/g, and high TBN of about 200 mgKOH/g to as high as about 600 mgKOH/g. Mixtures of low, medium, high TBN can be used, along with mixtures of calcium and magnesium metal based detergents, and including sulfonates, phenates, salicylates, and carboxylates. Further examples of mixed TBN detergents can be found as described in U.S. Pat. No. 7,704,930, which is incorporated herein by reference. A detergent mixture with a metal ratio of about 1, in conjunction of a detergent with a metal ratio of about 2, and as high as a detergent with a metal ratio of about 5 or 10 or 15, can be used. Borated detergents can also be used.

Alkaline earth metal phosphates may also be used as detergents and are known in the art.

Detergents may be simple detergents or what is known as hybrid or complex detergents. The latter detergents can provide the properties of two detergents without the need to blend separate materials. See U.S. Pat. No. 6,034,039

Suitable detergents include magnesium sulfonates, calcium sulfonates, calcium phenates, magnesium phenates, calcium salicylates, magnesium salicylates, and other related components (including borated detergents), and mixtures thereof. Preferred detergents include magnesium sulfonate, calcium sulfonate, magnesium phenate, calcium phenate, magnesium salicylate, calcium salicylate, and mixture thereof.

Other illustrative detergents that may be used in combination with the alkaline earth metal detergents include, for example, alkali metal detergents, or mixtures of alkali metal detergents.

In a detergent comprising a mixture of a magnesium salt of an organic acid and a calcium salt of an organic acid, the detergent ratio of magnesium metal to calcium metal ranges from about 1:0 to about 1:10, preferably from about 1:3 to about 1:8, more preferably from about 1:4 to about 1:6.

The magnesium and alkaline earth metal contributed by the detergent is present in the lubricating oil in an amount from about 500 ppm to about 5000 ppm, preferably from about 1000 ppm to about 2500 ppm. The magnesium contributed by the detergent is present in the lubricating oil in an amount from about 100 ppm to about 3000 ppm, preferably from about 300 ppm to about 2500 ppm, more preferably from about 750 ppm to about 2000 ppm.

The total base number (TBN), as measured by ASTM D2896, contributed by the detergent ranges from about 2 mg KOH/g to about 17 mg KOH/g, preferably from about 4 mg KOH/g to about 14 mg KOH/g, more preferably from about 6 mg KOH/g to about 12 mg KOH/g. The TBN contributed by the magnesium detergent ranges from about 2 mg KOH/g to about 17 mg KOH/g, preferably from about 3 mg KOH/g to about 14 mg KOH/g, more preferably from about 5 mg KOH/g to about 10 mg KOH/g.

Antioxidant

Antioxidant may impede oxidation degradation of the base oil resulting from, for example, metal deposition and/or viscosity increases, during system use or circulating of the lubricating oil. In various aspects, the lubricating composition may include greater than or equal to about 0.80 wt. % to less than or equal to about 3.00 wt. %, optionally greater than or 1.10 wt. % to less than or equal to about 2.50 wt. %, and in certain aspects, optionally greater than or 1.60 wt. % to less than or equal to about 2.40 wt. %, of the one or more antioxidants.

In various aspects, phenol-based antioxidants and amine-based antioxidants are useful. For example, the lubricating composition may include greater than or 0.30 wt. % to less than or equal to about 2.00 wt. %, optionally greater than or 0.40 wt. % to less than or equal to about 1.50 wt. %, and in certain aspects, optionally greater than or 0.60 wt. % to less than or equal to about 1.20 wt. % of one or more phenol-based antioxidants; and greater than or 0.70 wt. % to less than or equal to about 2.00 wt. %, optionally greater than or 0.80 wt. % to less than or equal to about 1.50 wt. %, and in certain aspects, optionally greater than or 0.90 wt. % to less than or equal to about 1.20 wt. % of one or more amine-based antioxidants. For example, the lubricating composition may include an effective amount of the nitrogen atoms defining the one or more amine-based antioxidants greater than or equal to about 300 ppm to less than or equal to about 1,000 ppm, and in certain aspects, optionally greater than or equal to about 400 ppm to less than or equal to about 600 ppm. As discussed in more detailed below, for example in the instance of examples five and six, amounts of the one or more amine-based antioxidants greater than or equal to about 0.70 wt. % may aid in the reduction or elimination lead elution, as well as in the improvement of detergency.

In various aspects, a mass ratio between the metal atoms of the one or more metal-based detergents and the nitrogen atoms derived from the one or more antioxidants and an alkenylsuccinimide compound (B3) may be about 1:2. For example, in the instance of calcium detergents the mass relationship may be express as

$1.0 \leq \frac{M}{N} \leq 2.0,$

in certain aspects, optionally

$1.5 \leq \frac{M}{N} \leq 2.0,$

in certain aspects, optionally

$1.7 \leq \frac{M}{N} \leq 2.0 .$

Example phenol-based antioxidants include monophenol-based antioxidants, such as 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and octadecyl -3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; diphenol-based antioxidants, such as 4,4′-methylenebis(2,6-di-tert-butylphenol), 2,2′-methylenebis(4-ethyl-6-tert-butylphenol); and hindered phenol-based antioxidants. Example amine-based antioxidants include, diphenylamine-based antioxidants, such as diphenylamine; alkylated diphenylamines having alkyl group, where the carbon number (n) is 3≤n≤20, such as dialkyldiphenylamine; and naphthylamine-based antioxidants, such as α-naphthylamine, phenyl-α-naphthylamine, and a substituted phenyl-α-naphthylamine having an alkyl group, where the carbon number (n) is 3≤n≤20.

Further examples of amine-based antioxidants include monoalkylormonoalkenylamines, such as hexylamine, (secondary hexy-1)amine, octylamine, (secondary octyl)amine, 2-ethylhexylamine, decylamine, (secondary decyl)amine, dodecylamine, (secondary dodecyl)amine, tetradecylamine, (secondary tetradecyl)amine, hexadecylamine, (secondary hexadecyl)amine, octadecylamine, (secondary octadecyl)amine, and oleylamine; secondary amines, such as N-hexylmethylamine, N-(secondary hexyl)methylamine, N-cyclohexylmethylamine, N-2-ethylhexylmethylamine, N-(secondary octyl)methylamine, N-decylmethylamine, N-(secondary decyl)methylamine, N-dodecylmethylamine, N-(secondary dodecyl)methylamine, N-tetradecylmethylamine, N-hexadecylmethylamine, N-stearylmethylamine, N-oleylmethylamine, dibutylamine, di(secondary butyl)amine, dihexylamine, di(secondary hexyl)amine, dibenzylamine, dioctylamine, bis(2-ethylhexyl)amine, di(secondary octyl)amine, didecylamine, di(secondary decyl)amine, didodecylamine, di(secondary dodecyl)amine, ditetradecylamine, dihexadecylamine, distearylamine, dioleylamine, bis(2-hexyldecyl)amine, bis(2-octyldodecyl)amine, and bis(2-decyltetradecyl) amine; N-alkyl- or N-alkenyldiamines such as N-butylethylenediamine, N-octylethylenediamine, N-(2-ethylhexyl)ethylenediamine, N-dodecylethylenediamine, N-octadecylethylenediamine, N-butyl-1,3-propanediamine, N-octyl-1,3-propanediamine, N-(2-ethylhexyl)-1,3-propanediamine, N-decyl-1,3-propanediamine, N-dodecyl-i,3-propanediamine, N-tetradecyl-1,3-propanediamine, N-hexadecyl-1,3-propanediamine, N-octadecyl-1,3-propanediamine, N-oleyl-1,3-propanediamine, N-butyl-1,6-hexylenediamine, N-octyl-1,6-hexylenediamine, N-(2-ethylhexyl)-1,6-hexylenediamine, N-dodecyl-1,6-hexylenediamine, N-octadecyl-1,6-hexylenediamine, and N-oleyl-1,6-hexylenediamine; N-alkyl or N-alkenylmonoethanolamines, such as N-hexylmonoethanolamine, N-octylmonoethanolamine, N-decylmonoethanolamine, N-dodecylmonoethanolamine, N-tetradecylmonoethanolamine, N-hexadecylmonoethanolamine, N-octadecylmonoethanolamine, and N-oleylmonoethanolamine; 2-hydroxyalkyl primary amines such as 2-hydroxyhexylamine, 2-hydroxyoctylamine, 2-hydroxydecylamine, 2-hydroxydodocylamine, 2-hydroxytetradecylamine, 2-hydroxyhexadecylamine, and 2-hydroxyoctadecylamine; and N-2-hydroxyalkyl secondary amines such as N-2-hydroxyhexylmethylamine, N-2-hydroxyoctylmethylamine, N-2-hydroxydecylmethylamine, N-2-hydroxytetradecylmethylamine, N-2-hydroxyhexadecylmethylamine, N-2-hydroxyoctadecylmethylamine, N-2-hydroxyhexylethylamine, N-2-hydroxyoctylethylamine, N-2-hydroxydecylethylamine, N-2-hydroxytetradecylethylamine, N-2-hydroxyhexadecylethylamine, N-2-hydroxyoctadecylethylamine, N-2-hydroxyhexylbutylamine, N-2-hydroxyoctylbutylamine, N-2-hydroxydecylbutylamine, N-2-hydroxytetradecylbutylamine, N-2-hydroxyhexadecylbutylamine, N-2-hydroxyoctadecylbutylamine, N-2-hydroxyhexylmonoethanolamine, N-2-hydroxyoctylmonoethanolamine, N-2-hydroxydecylmonoethanolamine, N-2-hydroxytetradecylmonoethanolamine, N-2-hydroxyhexadecylmonoethanolamine, N-2-hydroxyoctadecylmonoethanolamine, bis(2-hydroxyoctyl)amine, bis(2-hydroxydecyl)amine, bis(2-hydroxydodecyl)amine, bis(2-hydroxytetradecyl)amine, bis(2-hydroxyhexadecyl) amine, and bis(2-hydroxyoctadecyl)amine.

Other Components

In various aspects, the one or more lubricating additives may further comprise one or more other components. For example, in certain variations, the one or more lubricating additives may further include one or more anti-wear and/or extreme pressure agents, one or more viscosity index improvers, one or more pour-point depressants or pour point depressing agents, one or more antifoam agents, and/or one or more metal deactivators.

For example, in various aspects, the lubricating composition may further comprise one or more anti-wear and/or extreme pressure agents, such as zinc dialkyldithiophosphate (ZnDTP). The lubricating composition may include greater than or equal to about 0.20 wt. % to less than or equal to about 0.75 wt. %, optionally about greater than or equal to about 0.25 wt. % to less than or equal to about 0.50 wt. %, and in certain aspects, optionally about greater than or equal to about 0.25 wt. % to less than or equal to about 0.40 wt. %, of the one or more anti-wear and/or extreme pressure agents. In certain variations, the content of zinc dialkyldithiophosphate (ZnDTP) in terms of zinc atoms maybe greater than or equal to about 0.005 wt. % to less than or equal to about 0.10 wt. %, optionally greater than or equal to about 0.01 wt. % to less than or equal to about 0.08 wt. %, and in certain aspects, greater than or equal to about 0.015 wt. % to less than or equal to about 0.07 wt. %. Amounts of zinc greater than or equal to about 0.005 wt. % to less than or equal to about 0.10 wt. % may aid in the anti-wear property, as well as in the improvement of detergency and anti-oxidation. Amounts of zinc exceeding 0.1 wt. %, may diminish anti-oxidation properties and increase amounts of available sulfate ash.

In various aspects, the lubricating composition may further include one or more viscosity index improvers, such as a star-shaped olefin-based copolymers and/or star-shaped styrene-based copolymer (such as styrene-diene copolymer and styrene-isoprene copolymer), each having a molecular weight (MW) of greater than or equal to about 200,000 to less than or equal to about 1,000,000, optionally greater than or equal to about 400,000 to less than or equal to about 900,000, optionally greater than or equal to about 600,000 to less than or equal to about 850,000, and in certain aspects, optionally about 780,000. As the skilled artisan will recognize, star-shaped polymers are those having branched structure where three or more chain polymers are bonded at one point. In certain aspects, the lubricating composition may include greater than or equal to about 0.3 wt. % to less than or equal to about 0.6 wt. %, and in certain aspects, optionally greater than or equal to about 0.3 wt. % to less than or equal to about 0.5 wt. %, of the one or more viscosity index improvers. The one or more viscosity index improvers may be added so that the lubricating oil has a kinematic viscosity at 100° C. of greater than or equal to about 9.3 mm²/s to less than or equal to about 16.2 mm²/s, and in certain aspects, optionally greater than or equal to about 12.5 mm²/s to less than or equal to about 16.2 mm²/s.

In various aspects, the lubricating composition may further include one or more pour-point depressants or pour point depressing agents, such as a polymethacrylate having a molecular weight (MW) of greater than or equal to about 10,000 to less than or equal to about 200,000, optionally greater than or equal to about 50,000 to less than or equal to about 150,000, optionally greater than or equal to about 50,000 to less than or equal to about 100,000, and in certain aspects, optionally about 69,000. Such pour-point depressants may lower a minimum temperature at which the lubricating oil may be poured. In various aspects, the lubricating composition may include greater than or equal to about 0.15 wt. % to less than or equal to about 0.25 wt. %, and in certain aspects, optionally about 0.20 wt. %, of the one or more pour-point depressants.

In various aspects, the lubricating composition may further include, one or more antifoam agents. Antifoam agents may advantageously be added to the lubricant composition so as to reduce or prevent the formation of stable foams. Silicon and organic polymers are typical antifoam agents. For example, polysiloxane, such as silicon oil or polydimethyl siloxane, provide antifoam properties. The lubricating additive may include greater than or equal to about 0.05 wt. % to less than or equal to about 0.15 wt. %, and in certain aspects, optionally about 0.10 wt. %, of the one or more antifoam agents.

In various aspects, the lubricating additive may further include, one or more metal deactivators, such as one or more benzotriazol-based compounds. For example, the lubricating additive may include less than or equal to about 0.10 wt. %, and in certain aspects, optionally about 0.05 wt. %, of the one or more metal deactivators.

Other Properties of the Lubricating Composition

The sulfated ash of the lubricating composition may range from about 0.3 wt. % to about 1.2 wt %, preferably from about 0.4 wt. % to about 1.0 wt %, and more preferably from about 0.5 wt. % to about 0.8 wt %.

Method

The present disclosure provides a method for lubricating natural gas engines and landfill gas engines using a lubricating composition. The present disclosure further provides a method for making a lubricating composition, such as the lubricating composition detailed above. The method includes adding greater than or equal to about 3 wt. % to less than or equal to about 15 wt. %, and in certain aspects, optionally greater than or equal to about 5 wt. % to less than or equal to about 10 wt. %, of the one or more lubricating additives to a base oil. For example, in various aspects, the one or more lubricating additive may be added successively to the base oil to form the lubricating composition. In certain other variations, the method may include admixing the one or more lubricating additive and adding the admixture to the base oil so as to form a lubricating composition such as further detailed above.

EXAMPLES

Embodiments and features of the present disclosure are further illustrated through the following non-limiting examples.

Various example lubrication compositions may be prepared in accordance with various aspects of the present disclosure. For example, Table 1 summarizes the compositional details and properties of example lubrication compositions prepared in accordance with various aspects of the present disclosure, and Tables 2 summarizes the composition details and properties of the comparative lubrication compositions. In each instance, the lubrication composition includes a base oil such as Group II mineral oil having a kinematic viscosity at 100° C. of about 12 mm²/s and one or more lubricating additives.

In various aspects, the one or more lubricating additives include one or more dispersants, one or more metal-based detergents, and/or one or more antioxidants. For example, in each instance, the lubrication composition may include one or more dispersants, such as a boron-containing succinimide having a boron content of about 1.3 wt. % and a nitrogen content of about 1.23 wt. % and/or polybutenylsuccinimide having a nitrogen content of about 1.34 wt. %. The lubricating composition may include one or more metal-based detergents, such as a calcium-based detergent, such as overbased calcium salicylate having a calcium content of about 8.0 wt. % and a base value determined, for example, using a perchloric acid method, of about 225 mgKOH/g; a neutral calcium sulfonate having a calcium content of about 2.6 wt. % and a base value determined, for example, using a perchloric acid method, of about 27.5 mgKOH/g; and/or an overbased calcium sulfonate having a calcium content of about 11.6 wt. % and a base value determined, for example, using a perchloric acid method, of about 300 mgKOH/g. The lubricating composition may include a magnesium-based detergent, such as overbased magnesium sulfonate having a magnesium content of about 9.1 wt. % and a base value of about 405 mgKOH/g. The lubricating composition may include one or more antioxidants, such as an amine-based antioxidant and/or a phenol-based antioxidant. For example, the lubricating composition may include an amine-based antioxidant, such as dialkyldiphenylamine having a nitrogen content of about 4.5 wt. %. The lubricating composition may include a phenol-based antioxidant, such as 4,4′-Methylenebis(2,6-di-tert-butylphenol).

In still further variations, the lubricating composition may also include one or more other lubricating additives, such as one or more anti-wear and/or extreme pressure agents, one or more viscosity index improvers, one or more pour-point depressants or pour point depressing agents, one or more antifoam agents, and/or one or more metal deactivators. For example, the lubricating composition may include an anti-wear and/or extreme pressure agent, such as zinc dialkyldithiophosphate having a zinc content of about 8.9 wt. % and a phosphorus content of about 7.7 wt. %. The lubricating composition may include a viscosity index improver such as star-shaped styrene-based copolymer having an average molecular weight of about 780,000. The lubricating composition may include a pour point depressant, such as polymethacrylate having an average molecular weight of about 69,000. The lubricating composition may include an antifoam agent, such as silicones. The lubricating composition may include a metal deactivator, such as one or more benzotriazol-based compounds.

Example COMPONENT 1 2 3 4 5 6 7 base oil 92.86 93.06 93.06 92.06 93.36 93.56 93.26 borated succinimide 0.8 0.8 0.8 1.6 0.8 0.8 0.8 polybutenyl-succinimide 1.39 1.39 1.39 1.39 1.39 1.39 1.39 overbased calcium 1.2 1 1.2 1.2 1.2 1 1 salicylate neutral calcium sulfonate 0.11 0.11 0.11 0.11 0.11 0.11 0.11 overbased calcium sulfonate 0.19 0.19 0.19 0.19 0.19 0.19 0.19 overbased magnesium 0.26 0.26 0.26 0.26 0.26 0.26 0.26 sulfonate dialkyldiphenyl-amine 1 1 1 1 1 1 1 4,4′-methylenebis 1 1 0.8 1 0.5 0.5 0.8 (2,6-di-tert-butylphenol) zinc dialkyldithio-phosphate 0.34 0.34 0.34 0.34 0.34 0.34 0.34 star-shaped styrene-based 0.5 0.5 0.5 0.5 0.5 0.5 0.5 copolymer polymethacrylate 0.2 0.2 0.2 0.2 0.2 0.2 0.2 antiform agent 0.1 0.1 0.1 0.1 0.1 0.1 0.1 benzotriazol-based 0.05 0.05 0.05 0.05 0.05 0.05 0.05 compounds TOTAL 100 100 100 100 100 100 100 COMPOSITIONAL PROPERTY 1 2 3 4 5 6 7 Kinematic Viscosity 13.9 13.9 13.9 14.1 14.3 14.2 14.2 at 100° C. (mm²/s) Total Antioxidant Amount 2 2 1.8 2 1.50 1.50 1.8 (%) B content (ppm) 112 108 109 214 107 112 109 Ca content (ppm) 1254 1064 1223 1240 1221 1132 1072 Mg content (ppm) 237 237 237 237 237 237 237 Metal content (ppm) 1491 1301 1460 1477 1458 1369 1309 N content (ppm) 794 780 813 914 798 807 800 Mass Ratio (Ca/N) 1.58 1.36 1.5 1.36 1.53 1.4 1.34 Mass Ratio (M/N) 1.9 1.7 1.8 1.6 1.8 1.7 1.6 RESULTS 1 2 3 4 5 6 7 Increase in Acid Value 1.4 1.5 1.41 1.23 1.17 1.07 0.79 Lead Elution Volume (mg) 25 12 40 3 67 36 17 Merit Rating 9 3 3.5 9 3 3 3.5 Coking Amount (Mg) 8.7 9.9 14.7 17.4 11.2 14.3 16.5

Comparative Examples 1 2 3 4 COMPONENT base oil 93.26 93.66 93.26 90.22 borated succinimide 0.8 0.8 0.4 1.6 polybutenyl-succinimide 1.39 1.39 1.39 4.18 overbased calcium salicylate 1.2 1 1.2 1.75 neutral calcium sulfonate 0.11 0.11 0.11 0 overbased calcium sulfonate 0.19 0.19 0.19 0 overbased magnesium sulfonate 0.26 0.26 0.26 0 dialkyldiphenyl-amine 0.6 0.6 1 0.8 4,4′-methylenebis 1 0.8 1 0.6 (2,6-di-tert-butylphenol) zinc dialkyldithio-phosphate 0.34 0.34 0.34 0.5 star-shaped styrene-based 0.5 0.5 0.5 0 copolymer polymethacrylate 0.2 0.2 0.2 0.2 antiform agent 0.1 0.1 0.1 0.1 benzotriazol-based compounds 0.05 0.05 0.05 0.05 TOTAL 100 100 100 100 COMPOSITIONAL PROPERTY Kinematic Viscosity 13.9 14.3 14.1 13.9 at 100° C. (mm²/s) Total Antioxidant Amount (%) 1.6 1.4 2 1.4 B content (ppm) 108 104 57 213 Ca content (ppm) 1215 1096 1231 1372 Mg content (ppm) 237 237 237 0 Metal content (ppm) 1452 1333 1468 1372 N content (ppm) 600 621 798 1436 Mass Ratio (Ca/N) 2.03 1.76 1.54 0.96 Mass Ratio (M/N) 2.4 2.1 1.8 1.0 RESULTS Increase in Acid Value 1.64 1.52 0.98 1.61 Lead Elution Volume (mg) 19 11 82 224 Merit Rating 2.5 1 3 9 Coking Amount (Mg) 10.9 15.2 12.8 24.5

The example lubrication compositions prepared in accordance with various aspects of the present disclosure, as summarized in Table 1 above, may be subject to various performance tests. For example, 100 g of each of the example lubricating oil compositions may be placed in a glass test tube (e.g., 40 mm in diameter×300 mm in length) and a lead plate (e.g., 10 mm×20 mm×1 mm) may be polished and immersed in the test oil. A corrosion test may be performed on the lead plate. The corrosion test may be performed at an oil temperature of about 140° C. for about 96 hours under blowing the air at a flow rate of about 250 mL/h and the NO_xat a flow rate of about 100 mL/h. The result of such corrosion tests may be evaluated by the elution amount of lead. The elution amounts of lead may be measured using ICP according to ASTM D4951 requirements. The difference of acid value between fresh oil and aged oil may be measured according to ASTM D664 (Aged Oil Value—Fresh Oil Value). Similarly, each of the example lubrication compositions may be subject to hot tube tests, which may be performed by setting the test temperature to about 300° C. for about 16 hours and making other conditions in conformity with those of JPI-5S-55-99. Conforming to JPI-5S-55-99, a lacquer may be attached to a test tube after the test was evaluated between Point 0 (black) and Point 10 (colorless) and evaluated on 11 grades (e.g., as the numerical value increases, a deposit is less and the detergency becomes better). After performance of such tests, the samples may be merited rated (e.g., three or more are considered acceptable). Further still, each of the example lubrication compositions may be subjected to panel coking tests. Such test may be performed continuously for about six hours with a panel-coking tester according to Fed. Test Method Std. 791B-3462 under the condition of a panel temperature of 320° C. and an oil temperature of 100° C., and in a cycle of a splash time of 15 seconds and a suspend time of 45 seconds. After completing the test, the coking amount attached to the panel may be measured. A smaller coking amount can be understood as a lubricating composition with better high temperature detergency.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. A lubricating composition comprising:

one or more boron-containing compounds, wherein the lubricating composition comprises greater than or equal to about 60 ppm to less than or equal to about 300 ppm of boron atoms that define the one or more boron-containing compounds;

one or more metal-based detergents, wherein the lubricating composition comprises greater than or equal to about 1,100 ppm of metal atoms that define the one or more metal-based detergents;

greater than or equal to about 0.70 wt. % to less than or equal to about 2.00 wt. % of one or more amine-based antioxidants;

greater than or equal to about 0.30 wt. % to less than or equal to about 2.00 wt. %, of one or more phenol-based antioxidants; and

a base oil balance, wherein a mass ratio between nitrogen atoms (N) and metal atoms (M) in the lubricating oil (M/N) is greater than or equal to about 1.0 to less than or equal to about 2.0.

2. The lubricating composition of claim 1, wherein a combined amount of the one or more amine-based antioxidants and the one or more phenol-based antioxidants is greater than or equal to about 1.5 wt. %.

3. (canceled)

4. (canceled)

5. The lubricating composition of claim 1, wherein the lubricating composition comprises greater than or equal to about 1,200 ppm of metal atoms defining the one or more metal-based detergents.

6. The lubricating composition of claim 1, wherein the one or more boron-containing compounds comprise borated succinimide.

7. The lubricating composition of claim 1, wherein the one or more metal detergents comprise at least one of a calcium detergent and a magnesium detergent.

8. The lubricating composition of claim 7, wherein the lubricating composition comprises greater than or equal to about 1000 ppm to less than or equal to about 1400 ppm of calcium atoms, and greater than or equal to about 100 ppm to less than or equal to about 400 ppm of magnesium atoms.

9. (canceled)

10. The lubricating composition of claim 1, wherein the lubricating composition further comprises greater than or equal to about 0.20 wt. % to less than or equal to about 0.75 wt. % of one or more anti-wear and/or extreme pressure agents.

11. The lubricating composition of claim 10, wherein the one or more anti-wear and/or extreme pressure agents comprise zinc dialkyldithiophosphate (ZnDTP).

12. The lubricating composition of claim 1, wherein the lubricating composition further comprises greater than 0 wt. % to less than or equal to about 3.0wt. % of one or more viscosity index improvers.

13. A method for forming a lubricating composition, the method comprising:

adding to a base oil one or more boron-containing compounds such that the lubricating composition comprises greater than or equal to about 60 ppm to less than or equal to about 300 ppm of boron atoms that define the one or more boron-containing com pounds;

adding to the base oil one or more metal-based detergents such that the lubricating composition comprises greater than or equal to about 1,100 ppm of metal atoms that define the one or more metal-based detergents;

adding to the base oil greater than or equal to about 0.70 wt. % to less than or equal to about 2.00 wt. % of one or more amine-based antioxidants; and adding to the base oil greater than or equal to about 0.30 wt. % to less than or equal to about 2.00 wt. %, of one or more phenol-based antioxidants,

wherein a mass ratio between nitrogen atoms (N) and metal atoms (M) in the lubricating oil (M/N) is greater than or equal to about 1.0 to less than or equal to about 2.0.

14. (canceled)

15. The method of claim 13, wherein the one or more boron-containing compounds comprise boron succinimide.

16. The method of claim 13, wherein the one or more metal detergents comprise at least one of a calcium detergent and a magnesium detergent.

17. (canceled)

18. The method of claim 13, wherein the lubricating composition further comprises greater than or equal to about 0.25 wt. % to less than or equal to about 0.75 wt. % of one or more anti-wear and/or extreme pressure agents.

19. The method of claim 13, wherein the lubricating composition further comprises gre3ater than 0 wt. % to less than or equal to about 0.75 wt. % of one or more viscosity index improvers.