ES2914785T3 - Lubricant composition including N-alkylated dianiline - Google Patents

Abstract

A lubricating composition comprising: a) an oil of lubricating viscosity; b) at least 0.1% by weight of an N-alkylated dianiline compound; c) at least 0.1% by weight of an ashless antioxidant selected from a diarylamine antioxidant, a phenolic antioxidant and combinations of these, and d) at least 0.01% by weight of an overbased calcium detergent; wherein the lubricant composition comprises less than 0.15 weight percent phosphorus; and wherein the N-alkylated dianiline is an N,N'-alkylated dianiline compound represented by the formula: **(See formula)** wherein R1 and R2 are independently selected from alkyl groups of 1 to 24 carbon atoms , said alkyl groups are selected from acyclic alkyl groups, cyclic alkyl groups and combinations of these.

Description

DESCRIPTION

Lubricant composition including N-alkylated dianiline

Background

The illustrative embodiment relates to additives for lubricating compositions and finds particular application in connection with N-alkylated dianilines to improve deposit control as deposit enhancers in internal combustion engines.

United States patent no. US 3,779,923 describes alkylated methylenedianiline tars as antioxidants in lubricating compositions. The compounds are formed with a phosphorus-based catalyst.

United States patent no. US 8,242,066 discloses aniline compounds useful as ashless TBN sources for lubricating oil compositions that are compatible with fluoroelastomeric engine gasket materials.

United States patents nos. 4100082; 4200545; 4320021 and 4663063; 4708809 generally describe aminophenol compounds as lubricating oil additives (eg, dispersants/detergents).

The document no. US 2016/115418 A1 describes a lubricating composition containing an oil of lubricating viscosity and an N-acylated aromatic amine compound, as well as methods for lubricating an internal combustion engine by supplying said composition to said engine and using the N-acylated aromatic amine compound as a TBN enhancer.

One test to evaluate deposit formation is the "Standard Test Method for Determining Deposits on Pistons at Moderately High Temperature by Thermal Oxidation Engine Oil Simulation Test-TEOST MHT", ASTM D7097-09. MHT TEOST, as it will be referred to in this description, is a bench test that is designed to predict the deposit formation tendencies of engine oil on the piston ring belt and piston crown top area during service, and is one of the test methods required in Specification D 4485 to define engine oils identified by API category.

Some methylenedianiline (MDA) compounds have been found to improve thermal oxidation performance in motor oils and enhance thin film antioxidant capacity. However, formulating a high performance motor oil in MHT TEOST can compromise performance in other key areas. For example, adding dispersants and detergents in large quantities can negatively affect the viscometric properties of the lubricant composition or the performance of the seals.

It would be desirable if a lubricant composition were capable of providing good control of deposits, both in running engine tests and in bench tests such as MHT TEOST, while also providing other performance properties.

Short description

The present invention provides a lubricant composition comprising: a) an oil of lubricating viscosity; b) at least 0.1% by weight of an N-alkylated dianiline compound; c) at least 0.1% by weight of an ashless antioxidant selected from a diarylamine antioxidant, a phenolic antioxidant and combinations of these; and d) at least 0.01% by weight of an overbased calcium detergent; wherein the lubricant composition comprises less than 0.15 weight percent phosphorous; and wherein the N-alkylated dianiline is an N,N'-alkylated dianiline compound represented by the formula:

wherein R1 and R2 are independently selected from alkyl groups of 1 to 24 carbon atoms, said alkyl groups are selected from acyclic alkyl groups, cyclic alkyl groups, and combinations thereof.

In another aspect, the present invention provides the use of the inventive lubricant composition to reduce deposit formation in an internal combustion engine. In another aspect, the present invention provides the use of the inventive lubricant composition for lubricating an internal combustion engine.

In various embodiments of the present invention:

The lubricant composition has a TBN of at least 4 mg KOH/g, measured in accordance with ASTM D-2896.

The N-alkyl group is a cyclohexyl group.

The N-alkylated dianiline compound is at least 0.15% by weight, or at least 0.2% by weight, or at least 0.4% by weight of the lubricant composition.

The N-alkylated dianiline compound is up to 4.0 weight percent of the lubricant composition, or up to 3.0 weight percent, or up to 1.5 weight percent, or up to 1.2 weight percent of the lubricant composition.

The N-alkylated dianiline compound is selected from the group consisting of Structures A1, A-2, A-3, A-4, A-5, A-6 and A8 described below, and mixtures thereof.

The N-alkylated dianiline compound is selected from 4,4'-2-ethylhexylmethylenedianiline, 4,4'-cyclohexylmethylenedianiline, and mixtures thereof.

The oil of lubricating viscosity is at least 40 weight percent of the lubricating composition.

The ashless antioxidant is at least 0.2% by weight, or at least 0.4% by weight, or at least 0.6% by weight, or up to 4% by weight, or up to 1.2% by weight, or up to 1% by weight of the lubricant composition.

The ratio of the ashless antioxidant to the N-alkyldianiline compound is from 20:1 to 1:20.

The ashless antioxidant includes a phenolic ester and a diarylamine.

The ashless antioxidant further includes a sulfurized olefin.

The overbased calcium detergent is selected from sulfonates, non-sulfur containing phenates, sulfur containing phenates, salixarates, salicylates, mixtures of these and borated equivalents of these.

The overbased calcium detergent is present in an amount to supply the composition with at least 2 mg KOH/g total base number (TBN), measured in accordance with ASTM D-2896.

The overbased calcium detergent is at least 0.1 wt%, or at least 0.5 wt%, or up to 3 wt%, or up to 2 wt% of the lubricant composition.

A ratio of calcium to magnesium in the lubricant composition, by weight, is at least 9:10.

The lubricant composition further includes a polyolefin succinimide dispersant, wherein the polyolefin of the polyolefin succinimide has a number average molecular weight of at least 300.

The lubricant composition further includes a zinc dialkyldithiophosphate.

The lubricant composition includes at least 0.02 weight percent phosphorus.

The N-alkylated dianiline compound is a reaction product of a dianiline with at least one of an aldehyde and a ketone.

Detailed description

Aspects of the invention relate to lubricating compositions, their use to lubricate an internal combustion engine, and their use to reduce deposit formation in an internal combustion engine. The lubricant composition includes at least 0.1% by weight of an N-alkylated dianiline compound, an oil of lubricating viscosity, at least 0.1% by weight of an ashless antioxidant, and at least 0.01% by weight of an overbased calcium detergent. The ashless antioxidant is selected from diarylamine antioxidants, phenolic antioxidants, and mixtures of these. The lubricant composition includes less than 0.15% by weight of phosphorous. The N-alkylated dianiline

In the lubricant composition, the illustrative N-alkylated dianiline compound improves deposit performance, as measured by the MHT TEOST, while providing good TBN, without negatively affecting (and in some cases improving) antioxidant performance, when It is formulated for heavy duty (HD) diesel engines and passenger car engine applications. For example, in tests, N,N'-dicyclohexyl methylenedianiline (Cy MDA) can provide improvements in MHT TEOST in both HD and HT formulations. passenger cars, while aiding antioxidant performance, particularly under the Daimler oxidation test in an HD formulation.

In the illustrative N-alkylated dianiline compound, the two aromatic rings are hydrocarbylene coupled through a methylene group. The N-alkylated methylenedianiline compounds can be easily prepared.

By "N-alkylated" is meant that an alkyl group is attached to the dianiline through one or both of the amino groups attached to the aromatic rings of the dianiline. Each of these N-alkyl groups is selected from Ci-C24 alkyl groups, which alkyl groups are selected from acyclic alkyl groups, cyclic alkyl groups, and combinations of these. In the present invention, each amino group of dianiline has no more than one alkyl group. Illustrative N-alkylated methylenedianiline is an N,N'-alkylated methylenedianiline, in which both amino groups are alkylated.

Illustrative N,N'-alkylated methylenedianiline contains no more than two aromatic rings linked by a methylene group. While methods for generating the N-alkylated dianiline compound can result in structures having more than two aromatic rings linked by hydrocarbylene groups, in the illustrative embodiment, a molar ratio of these N-alkylated polyaromatic aniline compounds to the compound of N-alkylated dianiline in the lubricant composition cannot be higher than 1:10.

The N-alkylated dianiline compound of the present invention is a 4,4'-N-alkylated dianiline compound represented by the formula:

Structure IV.

Representative acyclic alkyl groups of the general formula CnH2n+1 suitable for R1 and R2 include straight chain and branched chain alkyl groups, such as methyl, ethyl, n-propyl, n-butyl, pentyl, hexyl, heptyl, octyl, nonyl , decyl, undecyl, dodecyl, tridecyl, tetradecyl, hexadecyl, stearyl, icosyl, docosyl, tetracosyl, 1-methylpropyl, 2,2-dimethylpropyl, isobutyl, isopentyl, isohexyl, 2-ethylhexyl, isoheptyl, 2-ethylheptyl, 2-propylheptyl , isooctyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, isodecyl, 2-butyldecyl, 2-hexididecyl, 2-octyldodecyl, 2-hexyldodecyl, isotridecyl, 2-dodecylhexadecyl, 2-decyltetradecyl, 4-methyl-2-pentyl , 2-tetradecycloctyldecyl, branched monomethylisostearyl, and isomers and combinations of these. In particular embodiments, the acyclic alkyl group is branched at the second or higher carbon, such as 2-ethylhexyl, 2-ethylheptyl, 2-ethyloctyl, and the like.

Representative cyclic alkyl groups of the general formula CnH2n-1 suitable for R1 and R2 include cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, and combinations of these.

Examples of N-alkylated dianiline compounds include compounds of formulas A-1 through A-6 and A-8:

In specific embodiments, the N-alkylated dianiline compound is selected from 4,4'-2-cyclohexylmethylenedianiline (CY-MDA) (Formula A-1), and 4,4'-2-ethylhexylmethylenedianiline (EHL-MDA) (Formula A-2).

The N-alkylated dianiline compound is present in the lubricant composition in a concentration of at least 0.1% by weight and can be up to 5% by weight. For example, the concentration of the compound may be at least 0.15 wt%, or at least 0.4 wt%, or at least 1.5 wt%, or up to 5.0 wt%, or up to 2.5% by weight of the lubricant composition. The compound can also be present in a concentrate, alone or with other additives and with a minor amount of oil. In a concentrate, the amount of the compound can be at least 2 or at least 3 times the concentration in the lubricant composition.

As used herein, TBN is measured in accordance with ASTM D2896 - 15, Standard Test Method for Base Rate of Petroleum Products by Potentiometric Titration of Perchloric Acid, ASTM International, West Conshohocken, PA, 2011, DOI: 10.1520/D2896-15.

In various aspects, the N-alkylated dianiline compound has a TBN of at least 50 mg KOH/g, or at least 100 mg KOH/g, measured according to ASTM D2896.

In various embodiments, the lubricant composition has a TBN of at least 4 mg KOH/g, measured according to ASTM D-2896.

The N-alkylated dianiline compound is particularly effective in improving deposit performance in lubricating compositions having low phosphorus content. In the illustrative lubricant composition, the phosphorus content of the lubricant composition is up to 0.15% by weight, such as up to 0.12% by weight, or up to 0.11% by weight, or up to 0.08% by weight. weight, or up to 0.05% by weight, or up to 0.04% by weight, or up to 0.02% by weight. The phosphorus content of the lubricant composition may be at least 0.01% by weight, or at least 0.02% by weight, or at least 0.03% by weight. Suitable additives to provide such low levels of phosphorous to the lubricant composition include zinc dialkyl dithiophosphates (ZDDP), as described below.

Preparation methods of N-alkylated dianiline compound

Illustrative compounds can be prepared, for example, from dianilines, such as 4,4'-methylenedianiline. In one embodiment, the N-alkylated dianiline compounds are prepared by reacting a dianiline with one or more aldehydes or ketones in a 1:2 molar ratio or in excess in an alcoholic solvent, such as methanol or toluene.

The aldehyde or ketone can have the general formula:

.0

r5 - <

R6

, where

corresponds to R1 and R2 above, at least one of R5 and R6 is not H.

In one embodiment, the aldehyde or ketone may be a ^C2 - ^C12 aldehyde or ketone, such as a ^C2 - ^C9 aldehyde, or a ^C2 -C6 aldehyde or ^C3 - ^{C10 ketone} , or ketone. ^C3 - ^C7 .

Examples of ketones useful for forming the compound include methyl alkyl ketones and ethyl alkyl ketones of 3 to 12 carbon atoms where the alkyl group may be alicyclic or cyclic. Examples of such ketones include those in which the alkyl moieties are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, and the various isomeric forms thereof. Examples of ketones include acetone, 2-butanone, 2-pentanone, 3-pentanone, 4-methyl-2-butanone, 2-hexanone, 4-methyl-2-hexanone, 4-heptanone, 5-methyl-2-hexanone , 5,6-dimethyl-2-hexanone, 5,5-dimethyl-2-hexanone, 4,5-dimethyl-2-hexanone, 4-ethyl-2-hexanone, 5-ethyl-2-hexanone, 4.5 ,5-trimethyl-2-hexanone, 2-heptanone, 3-heptanone, 5,5-dimethyl-2-heptanone, 4,5-dimethyl-2-heptanone, 5-ethyl-2-heptanone, 4-ethyl-2 -heptanone, 2-octanone, 3-octanone, 4-octanone, 6-methyl-2-octanone, 7,7-dimethyl-2-octanone, 6-methyl-3-octanone, 6-ethyloctanone, 2-nonanone, 3 - nonanone, 4-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5-decanone, cyclobutanone, cyclopentanone, cyclohexanone, methylcyclohexanones, ethylcyclohexanones, cycloheptanone, cyclooctanone and the like.

As an example, 4,4'-methylenedianiline is reacted with an aldehyde/ketone in a 1:2 molar ratio or in excess in a suitable solvent, such as toluene, at a temperature above 100°C. The water formed in the reaction is removed. After the reaction is complete, the solvent is removed. The product can be purified by redissolving it in a suitable solvent, such as methanol, and adding sodium borohydride. The mixture is poured into water and the product is extracted with ethyl acetate. The solvent is removed which provides the purified product. An illustrative reaction scheme shown in Scheme 1:

Scheme 1:

where R ⁵ and R ⁶ are as described above.

N-Alkylated dianiline compounds can also be prepared by reacting a methylenedianiline and one or more aldehydes or ketones in a molar ratio of 1:2 or greater in the presence of hydrogen and a hydrogenation catalyst, such as platinum, palladium, cobalt or nickel, either as such or carried on a suitable support, such as carbon, in methanol as a solvent, as described, for example, in US Pat. 2,045,574 and 3,779,923.

In general, the reaction results in a monosubstitution of each -NH ² group, although a small amount of disubstituted compounds may be present.

A lubricant composition can be prepared by adding the N-alkylated dianiline compound, ashless antioxidant, and calcium overbased detergent to an oil of lubricating viscosity, optionally in the presence of other performance additives (as described herein below). ), or by adding reagents to form the N-alkylated dianiline compound to an oil of lubricating viscosity. The lubricant composition may further include additional performance additives, such as antioxidants, additional dispersants, anti-wear agents and friction modifiers. One method of forming a lubricating composition includes forming an N-alkylated dianiline compound and combining the N-alkylated dianiline compound with an oil of lubricating viscosity, an ashless antioxidant, and an overbased calcium detergent, to provide a lubricating composition comprising less than 0.15 weight percent phosphorus.

The ashless antioxidant

The lubricant composition includes at least 0.1% by weight of one or more ashless antioxidants (AAOs) selected from a diarylamine antioxidant, a phenolic antioxidant, and a mixture of these. The AAO may be present in the lubricant composition in a concentration of at least 0.2% by weight, such as at least 0.3% by weight, or up to 5% by weight, or up to 2.5% by weight, or up to 2% by weight, or up to 1% by weight. A weight ratio of the AAO to the N-alkylated dianiline compound can be at least 1:20 or up to 20:1.

Illustrative phenolic antioxidants useful herein include alkylated diphenylamine antioxidants, such as C ¹ -C ²⁴ monoalkylated, dialkylated, and polyalkylated diphenylamines, as described, for example, in US Pat. 2,943,112; 4,824,601; 5,672,752; 6,204,412; 6,315,925; 6,355,839 and US Publication Nos. 2015/0307803 and 2016/0017252. Particularly useful are monoalkylated and dialkylated diphenylamines in which the alkyl group(s) include(s) at least 6 carbon atoms, such as at least 8 or at least 9 carbon atoms.

Illustrative phenolic antioxidants that can be used include C7-C9 branched alkyl esters of 3,5-bis(1,1-dimethyl-ethyl)-4-hydroxy-benzenepropanoic acid, 2-tert-butylphenol, 2-tert-butyl- 4-methylphenol, 2-tert-butyl-5-methylphenol, 2,4-di-tert-butylphenol, 2,4-dimethyl-6-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, 3-tert- butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butyl-4-alkylphenols, such as 2,6-di-tert-butylphenol, 2,6-di-tert- butyl-4-methylphenol and 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-alkoxyphenols, such as 2,6-di-tert-butyl-4-methoxyphenol and 2,6-di-tert-butyl-4-ethoxyphenol, 3,5-di-tert-butyl-4-hydroxybenzylmercaptooctylacetate, alkyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionates, such as n -octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, n-butyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 2'-ethylhexyl- 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6-di-tert-butyl-a-dimethylamino-pcresol, 2,2'-methylene-bis(4-alkyl-6 -tert-butylphenol), such as 2,2'-methylenebis(4-methyl-6-tert-butylphenol and 2,2-methylenebis(4-ethyl-6-tert-butylphenol), bisphenols, such as 4,4' -butylidenebis(3-methyl-6-tert-butylphenol, 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-bis(2,6-di-tert-butylphenol), 2 ,2-(di-p-hydroxyphenyl)propane, 2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane, 4,4'-cyclohexylidenebis(2,6-tert-butylphenol), Hexamethylene glycol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], triethylene glycolbis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], 2,2' -thio-[diethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,9-bis{1,1-dimethyl-2-[3-(3-tert-butyl-4- hydroxy-5-methylphenyl)propionyloxy]ethyl}2,4,8,10-tetraoxaspiro[5.5]undecane, 4,4'-thiobis(3-methyl-6-tert-butylphenol) and 2,2'-thiobis (4,6-di-tert-butylresorcinol), polyphenols, such as tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionato]methane, 1,1,3-tris(2 -methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybe n-cyl)benzene, bis-[3,3'-bis(4'-hydroxy-3'-tert-butylphenyl)butyric]glycol acid ester, 2-(3',5'-di-tert-butyl-4- hydroxyphenyl)methyl-4-(2",4"-di-tert-butyl-3"-hydroxyphenyl)methyl-6-tert-butylphenol and 2,6-bis(2'-hydroxy-3'-tert-butyl- 5'-methylbenzyl)-4-methylphenol, p-t-butylphenol-formaldehyde condensates and p-t-butylphenol-acetaldehyde condensates.

Phenol-based antioxidants frequently contain a secondary butyl group and/or a tertiary butyl group as a steric hindrance group. The phenol group may be further substituted with a hydrocarbyl group (for example, a straight or branched alkyl) and/or a bridging group that is linked to a second aromatic group.

Examples of particularly suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4,4'-methylenebis-(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, 4-butyl-2,6-di-tert-butylphenol, 4-dodecyl-2,6 -di-tert-butylphenol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), as described, for example, in US publications no.

2009/0111720, 2010/0269774 and 2012/0103290. In one embodiment, the hindered phenol antioxidant can be an ester, such as those described in US Pat. 6,559,105, such as 3-(4-hydroxy-3,5-di-tert-butyl-phenyl)propionic acid alkyl alcohol esters. One such hindered phenol ester is sold as Irganox™ L-135, which is available from Ciba.

The phenolic antioxidant, when present in the lubricant composition, may be at least 0.5% by weight, or at least 1.5% by weight, or at least 2.5% by weight, and may be up to 5 % by weight, such as up to 4% by weight, or up to 3% by weight of the lubricant composition.

Examples of alkylated diphenylamines useful in the present description include those of the general formula:

wherein each of R7, R8, R9, and R10 is selected from H and ^C8 - ^C24 or ^C8 - ^C12 alkyl groups, and wherein at least one of R7, R8, R9, and R10 is not H. In one embodiment, R8 and R10 (and optionally also R9) are not H. Para substitution by the alkyl group is common.

Examples of alkylated diphenylamines include dinonyldiphenylamine, nonyldiphenylamine, octyldiphenylamine, dioctyldiphenylamine, dodecyldiphenylamine, decyldiphenylamine, and mixtures of these.

Methods for producing monoalkylated diphenylamines are described in US Pat.

5,672,752. Methods for selectively producing p,p'-dialkylated diphenylamines are described in US Publication No. 2016/0017252.

Other illustrative diarylamine antioxidants include alkylated phenylnaphthylamines of the general form:

where each of R7, R8 are as defined above and at least one of R7 and R8 is not H.

Examples of alkylated phenylnaphthylamines include octyl, dioctyl, nonyl, dinonyl, decyl, and dodecyl phenylnaphthylamines, such as N-(dodecylphenyl)naphthalen-1-amine:

In one embodiment, a ratio of diarylamine to the N-alkyldianiline compound is from 20:1 to 1:20.

The alkylated diarylamine, when present in the lubricant composition, may be at least 0.2% by weight, or at least 0.4% by weight, or at least 0.5% by weight, or at least 1.0%. by weight, or at least 2.5% by weight, and can be up to 5% by weight, such as up to 2.5% by weight, or up to 1.5% by weight of the lubricant composition. Mixtures of phenolic and/or alkylated diarylamine antioxidants may be employed. When both an alkylated diarylamine and a phenolic antioxidant are used, the combined amount of ashless antioxidant may be at least 0.8 wt%, or at least 1.5 wt%, or at least 3 wt%, and it can be up to 5% by weight, such as up to 4% by weight, or up to 3.5% by weight of the lubricant composition.

Overbased Calcium Detergent

In the present invention, the lubricant composition includes at least 0.01% by weight of an overbased calcium detergent. In one embodiment, the lubricant composition includes an alkaline earth metal overbased detergent in an amount sufficient to supply at least 2 mg KOH/g total base number (TBN), measured in accordance with ASTM D-2896-15, to the lubricant composition.

The overbased calcium detergent can be chosen from sulfonates, non-sulfur containing phenates, sulfur containing phenates, salixarates, salicylates and mixtures of these, or borated equivalents of these. Overbased detergent can be borated with a borating agent such as boric acid.

The overbased calcium-containing detergent can include "hybrid" detergents that are formed with mixed surfactant systems that include phenate and/or sulfonate components, for example, phenate/salicylates, sulfonate/phenates, sulfonate/salicylates, sulfonates/phenates/salicylates, as described; for example, in US Pat. Nos. 6,429,178; 6,429,179; 6,153,565; and 6,281,179. Where a hybrid sulfonate/phenate detergent is employed, the hybrid detergent can be considered equivalent to amounts of non-phenate and sulfonate detergents that introduce similar amounts of phenate and sulfonate soaps, respectively.

Examples of overbased calcium-containing detergents include calcium salts of sulfonates, phenates (including sulfur-containing and non-sulfur-containing phenates), salixarates, and salicylates. Such overbased sulfonates, salixarates, phenates, and salicylates can have a total base number of from 120 to 700, or from 250 to 600, or from 300 to 500 (on an oil-free basis).

Overbased sulfonates, salixarates, phenates, and salicylates typically have a total base number of 120 to 700 TBN. Overbased sulfonates typically have a total base number of 120 to 700, or 250 to 600, or 300 to 500 (on an oil-free basis).

By "overbased" is meant that the calcium is in excess of stoichiometric amounts relative to the soap counterion (eg, sulfonate). The overbased calcium detergent can have a metal:counterion ratio of at least 3:1, or at least 4:1, or at least 6:1.

Examples of sulfonate detergents include straight and branched alkylbenzene sulfonate detergents, and mixtures of these, which may have a metal ratio of at least 8, as described, for example, in US publication no. 2005065045. Linear alkylbenzenes can have the benzene ring attached anywhere in the linear chain, generally in the 2, 3, or 4 position, or mixtures of these. Linear alkylbenzene sulfonate detergents can be particularly useful in helping to improve fuel economy.

In one embodiment, the alkylbenzene sulfonate detergent can be a branched alkylbenzene sulfonate, a linear alkylbenzene sulfonate, or mixtures of these.

In one embodiment, the lubricant composition may be free of linear alkylbenzene sulfonate detergent. The sulfonate detergent can be a calcium salt of one or more oil-soluble alkyl toluene sulfonate compounds as described in US Publication No. 20080119378.

The lubricant composition includes at least 0.01 % by weight of overbased calcium detergent. The lubricant composition may include at least 0.1% by weight, or at least 0.5% by weight, of overbased calcium detergent and, in some embodiments, up to 3% by weight, or up to 2% by weight of detergent. (s) overalkalinized calcium.

Lubricating viscosity oil

The lubricating composition may include the oil of lubricating viscosity as a minor or major component thereof, such as at least 5% by weight, or at least 10% by weight, or at least 20% by weight, or at least 30% by weight. , or at least 40% by weight, or at least 60% by weight, or at least 80% by weight, or up to 98% by weight, or up to 95% by weight of the lubricant composition.

The amount of oil of lubricating viscosity present may typically be the difference remaining after subtracting from 100% by weight, the sum of the amount of the compound and antioxidant, as described above, and any other performance additives.

Suitable oils include natural and synthetic oils, oils derived from hydrocracking, hydrogenation, and hydrofinishing, crude, refined, re-refined, or mixtures of these. Unrefined, refined and re-refined oils, and natural and synthetic oils are described, for example, in document no. WO 2008/147704 and US publication no. 2010/197536. Synthetic oils can also be produced by Fischer-Tropsch reactions and can typically be hydroisomerized Fischer-Tropsch hydrocarbons or waxes. The oils can be prepared by a Fischer-Tropsch gas-to-liquid synthesis process as well as other gas-to-liquid processes.

Lubricating viscosity oils may also be defined as specified in the April 2008 version of "Appendix E - API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils", section 1.3 Subheading 1.3. "Base Stock Categories". The API Guidelines are also summarized in US Pat. 7,285,516. The five base oil groups are as follows: Group I (sulfur content >0.03% by weight, and/or <90% by weight of saturates, viscosity index of 80-120); Group II (sulfur content <0.03% by weight, and >90% by weight of saturates, viscosity index of 80-120); Group III (sulfur content <0.03% by weight, and >90% by weight of saturates, viscosity index >120); Group IV (all polyalphaolefins (PAO)); and Group V (all others not included in Groups I, II, III or IV). Illustrative lubricating viscosity oil includes one of API Group I, Group II, Group III, Group IV, Group V or mixtures thereof. In some embodiments, the oil of lubricating viscosity is one of API Group I, Group II, Group III or Group IV or mixtures of these. In some embodiments, the oil of lubricating viscosity is one of API Group I, Group II, or Group III or mixtures of these. In one embodiment, the oil of lubricating viscosity may be an API Group II, Group III mineral oil, a Group IV synthetic oil, or mixtures of these. In some embodiments, at least 5% by weight, or at least 10% by weight, or at least 20% by weight, or at least 40% by weight of the lubricant composition is a polyalphaolefin (Group IV).

The lubricant composition described herein may have an SAE viscosity grade of XW-Y, where X may be 0, 5, 10, or 15; and Y can be 16, 20, 30, or 40.

Lubricating viscosity oil may have a kinematic viscosity of up to 12 mm2/s or up to 8 mm2/s (cSt) at 100 °C and may be at least 12 mm2/s at 100 °C, and in other embodiments at least 3, 5mm2/s. As used herein, kinematic viscosity is determined at 100°C per ASTM D445-14, "Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)", ASTM International, West Conshohocken, PA, 2003, DOI: 10.1520/D0445-14 and may be referred to as KV_100.

The viscosity grade of the oil depends on the end use. For diesel and passenger car engines, the viscosity grade can be SAE-5W-30, SAE 10W-30, or SAE 15W-40. The base oil may be a mixture of two or more fractions having different oligomer distributions. A fraction rich in lower oligomers is typically mixed with a fraction rich in higher oligomers to achieve the desired oligomer distribution. However, any combination of fractions that produces a composite having the required distribution of oligomers is acceptable. The fractions used for said mixture can be different distillation cuts from the same process or can be obtained from completely different oligomerization processes. A single fraction can be used to produce different multigrade oils, for example SAE 10W-30 and SAE 15W-40 oils. The composite material obtained after mixing can be hydrogenated or the individual fractions can be hydrogenated before they are mixed.

For 2-stroke marine diesel engines, the viscosity grade can be from SAE-40 to SAE-60, which corresponds to a KV_100 of 12.5 to 26 mm2/s. SAE-50 grade oils, for example, have a KV_100 of 16.3-21.9 mm2/s. Cylinder oils for 2-stroke marine diesel engines can be formulated to achieve a KV_100 of 19 to 21.5 mm2/s. This viscosity can be obtained by a mixture of additives and base oils, for example containing Group I mineral bases such as neutral solvent (for example 500 NS or 600 NS) and Bright Stock bases. Any other combination of mineral, synthetic or plant-based bases can be used that, when mixed with the additives, have a viscosity compatible with SAE 50 grade.

As an example, an oil formulation suitable for use as a cylinder lubricant for slow speed 2-stroke marine diesel engines contains 18 to 25% by weight of a Group I base oil of type BSS (distillation residue, with a KV_100 of 28 - 32 mm ² /s, with a density at 15 °C of 895 - 915 kg/m ³ ), and 50 to 60% by weight of a Group I base oil of type SN 600 (distillate, with a density at 15 °C of 880 - 900 kg/m ³ , with a KV_100 of approximately 12 mm ² /s).

In certain embodiments, the lubricating composition may contain synthetic ester-based fluids. Synthetic esters can have a kinematic viscosity measured at 100°C of 2.5 mm ² /s to 30 mm ² /s. In one embodiment, the lubricant composition comprises less than 50% by weight of a synthetic ester-based fluid with a KV_100 of at least 5.5 mm ² /s, or at least 6 mm ² /s, or at least 8 mm ² /sec.

Illustrative synthetic oils include polyalpha olefins, polyesters, polyacrylates and polymethacrylates, and copolymers of these. Examples of synthetic esters include esters of a dicarboxylic acid (for example, selected from phthalic acid, succinic acid, alkylsuccinic acids, alkenylsuccinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, dimer of linoleic acid, malonic acid, alkylmalonic acids, and alkenylmalonic acids) with an alcohol (eg, selected from butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, and propylene glycol). Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl, the 2-ethylhexyl diester of dimer linoleic acid, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid. Esters useful as synthetic oils also include those prepared from C ⁵ to C ¹² monocarboxylic acids and polyols and from polyol ethers, such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tripentaerythritol. The esters can also be monoesters, such as those available under the trade name Priolube 1976 ^™ (C- ^is -CoO-C ²⁰ alkyl).

Synthetic ester base oils may be present in the lubricating composition in an amount less than 50 wt% % of the composition, or less than 40 wt%, or less than 35 wt%, or less than 28 wt%. , or less than 21% by weight, or less than 17% by weight, or less than 10% by weight, or less than 5% by weight of the composition. In one embodiment, the lubricant composition is without or substantially without a synthetic ester base fluid having a KV_100 of at least 5.5 mm ² /s.

Examples of natural oils include animal and vegetable oils, such as esters of long chain fatty acids. Examples include flaxseed oil, sunflower oil, sesame seed oil, beef tallow oil, lard oil, palm oil, castor oil, cottonseed oil, corn oil, peanut oil , soybean oil, olive oil, whale oil, menhaden oil, sardine oil, coconut oil, palm kernel oil, babassu oil, rapeseed oil and soybean oil.

The amount of oil of lubricating viscosity present is typically the remainder after subtracting from 100% by weight the sum of the amount of the N-alkylated methylenedianiline compound and the other performance additives. Other performance additives

In addition to the illustrative N-alkylated dianiline compound(s) described herein, the lubricant composition may further include one or more of the following additional performance additives: antioxidants (other than the foregoing ), dispersants, viscosity modifiers, anti-wear/anti-chafing agents, deactivators, friction modifiers, extreme pressure agents, foam inhibitors, demulsifiers, pour point depressants, corrosion inhibitors, seal expansion agents, enhancers of TBN and the like. The additional performance additive(s) may be suitable to provide the performance properties of a fully formulated lubricant composition, for example, a passenger car or HD motor lubricant.

A. Detergents

The lubricant composition optionally further includes at least one detergent, in addition to the overbased calcium detergent discussed above. Illustrative detergents useful in the present disclosure include overbased metal-containing detergents, where the metal is other than calcium.

The metal of the metal-containing detergent may be zinc, sodium, barium or magnesium. In one embodiment, the lubricant composition includes an alkaline earth metal overbased detergent in an amount sufficient to supply at least 2 mg KOH/g total base number (TBN), measured in accordance with ASTM D-2896-15, to the lubricant composition.

The overbased metal-containing detergent can be chosen from sulfonates, non-sulfur-containing phenates, sulfur-containing phenates, salixarates, salicylates, and mixtures of these, or borated equivalents of these. The overbased detergent can be borated with a borating agent such as boric acid.

Overbased metal-containing detergent may include "hybrid" detergents that are formed with mixed surfactant systems that include phenate and/or sulfonate components, e.g., phenate/salicylates, sulfonate/phenates, sulfonate/salicylates, sulfonates/phenates/salicylates, as described; for example, in US Pat. Nos. 6,429,178; 6,429,179; 6,153,565; and 6,281,179. Where a hybrid sulfonate/phenate detergent is employed, the hybrid detergent can be considered equivalent to amounts of non-phenate and sulfonate detergents that introduce similar amounts of phenate and sulfonate soaps, respectively.

Examples of overbased metal-containing detergents include zinc, sodium, and magnesium salts of sulfonates, phenates (including sulfur-containing and non-sulfur-containing phenates), salixarates, and salicylates. Said overbased sulfonates, salixarates, phenates and salicylates have a total base number of 120 to 700, or 250 to 600, or 300 to 500 (on an oil-free basis).

Typically, an overbased metal-containing detergent may be a zinc, sodium, or magnesium salt of a sulfonate, a phenate, a sulfur-containing phenate, a salixarate, or a salicylate. Overbased sulfonates, salixarates, phenates, and salicylates typically have a total base number of 120 to 700 TBN. Overbased sulfonates typically have a total base number of 120 to 700, or 250 to 600, or 300 to 500 (on an oil-free basis).

The overbased metal-containing detergent may be alkali or alkaline earth metal salts. In one embodiment, the overbased detergent can be sodium salts, calcium salts, magnesium salts, or mixtures thereof of phenates, sulfur-containing phenates, sulfonates, salixarates, and salicylates. In one embodiment, the overbased detergent is a calcium detergent, a magnesium detergent, or mixtures of these. In one embodiment, the overbased calcium detergent may be present in an amount that supplies at least 500 wppm calcium and no more than 3000 wppm calcium, or at least 1000 wppm calcium, or at least 2000 wppm calcium. ppm of calcium by weight, or not more than 2500 ppm of calcium by weight to the lubricant composition. In one embodiment, the overbased detergent may be present in an amount that supplies no more than 500 wppm magnesium to the lubricant composition, or no more than 330 wppm, or no more than 125 wppm, or no more of 45 ppm by weight. In one embodiment, the lubricant composition is essentially free of (ie, contains less than 10 ppm) magnesium resulting from the overbased detergent. In one embodiment, the overbased detergent may be present in an amount that supplies at least 200 wppm magnesium, or at least 450 wppm magnesium, or at least 700 wppm magnesium to the lubricant composition. In one embodiment, detergents containing both calcium and magnesium can be present in the lubricant composition. The calcium and magnesium detergents may be present such that the weight ratio of calcium to magnesium is from 10:1 to 1:10, or from 8:3 to 4:5, or from 1:1 to 1:3. In one embodiment, the overbased detergent is free or substantially free of sodium.

The overbased sulfonate detergent can have a metal ratio of 12 to less than 20, or 12 to 18, or 20 to 30, or 22 to 25.

Examples of sulfonate detergents include straight and branched alkylbenzene sulfonate detergents, and mixtures of these, which may have a metal ratio of at least 8, as described, for example, in US publication no. 2005065045. Linear alkylbenzenes can have the benzene ring attached anywhere in the linear chain, generally in the 2, 3 or 4 position, or be mixtures of these. Predominantly linear alkylbenzene sulfonate detergents can be particularly useful in helping to improve fuel economy.

In one embodiment, the alkylbenzene sulfonate detergent can be a branched alkylbenzene sulfonate, a linear alkylbenzene sulfonate, or mixtures of these.

In one embodiment, the lubricant composition may be free of linear alkylbenzene sulfonate detergent. The sulfonate detergent can be a metal salt of one or more oil-soluble alkyl toluene sulfonate compounds as described in US publication no. 20080119378.

The lubricant composition may include at least 0.01 wt% or at least 0.1 wt% detergent and, in some embodiments, up to 2 wt% or up to 1 wt% detergent.

B. Antioxidants

The lubricant composition optionally further includes at least one antioxidant, in addition to the AAOs listed above. Illustrative antioxidants useful in the present disclosure include sulfurized olefins. Examples of suitable olefins that can be sulfurized to form the sulfurized olefin include propylene, butylene, isobutylene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, undecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, and mixtures of these. In one embodiment, hexadecene, heptadecene, octadecene, nonadecene, eicosene, or mixtures of these and their dimers, trimers, and tetramers are especially useful olefins.

Alternatively, the olefin may be a Diels-Alder adduct of a diene such as 1,3-butadiene and an unsaturated ester such as butyl acrylate. Another class of sulfurized olefin includes fatty acids and their esters. Fatty acids are often obtained from vegetable oil or animal oil; and typically contain from 4 to 22 carbon atoms. Examples of suitable fatty acids and their esters include triglycerides, oleic acid, linoleic acid, palmitoleic acid, and mixtures of these. The fatty acids can be obtained from lard oil, tall oil, peanut oil, soybean oil, cottonseed oil, sunflower seed oil, or mixtures of these. In one embodiment, the fatty acids and/or the ester are mixed with olefins. When present, the lubricant composition may include at least 0.1 wt% or at least 0.5 wt%, or at least 1 wt% antioxidant, and in some embodiments up to 3 wt%, or up to 2.75% by weight, or up to 2.5% by weight, or up to 1.2% by weight of such additional antioxidants.

C. Dispersants

The lubricant composition optionally further includes at least one dispersant other than the illustrative compound. Illustrative dispersants include succinimide dispersants, Mannich dispersants, succinamide dispersants, and polyolefin esters, amides, and ester-amides of succinic acid, and mixtures thereof.

The succinimide dispersant can be derived from an aliphatic polyamine or mixtures thereof. The aliphatic polyamine can be an ethylene polyamine, a propylene polyamine, a butylene polyamine, or mixtures of these. In one embodiment the aliphatic polyamine can be an ethylene polyamine. In one embodiment the aliphatic polyamine may be selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyamine residues, and mixtures of these.

In one embodiment, the dispersant may be a polyolefin succinic acid ester, amide or ester-amide. A polyolefin succinic acid esteramide may be a polyisobutylene succinic acid which is reacted with an alcohol (such as pentaerythritol) and a polyamine as described above. Examples of polyolefin succinic acid esters include polyisobutylene succinic acid esters of pentaerythritol and mixtures thereof.

The dispersant may be an N-substituted long chain alkenyl succinimide. An example of an N-substituted long chain alkenyl succinimide is polyisobutylene succinimide. Typically, the polyisobutylene from which the polyisobutylene succinic anhydride is derived has a number average molecular weight of at least 300, or at least 350, or at least 500, or at least 550, or at least 750, and may be up to 5,000 or up to 3000, or up to 2500. Such succinimides can be formed, for example, from high vinylidene polyisobutylene and maleic anhydride. Succinimide dispersants and their preparation are described, for example, in US Pat. 3,172,892, 3,219,666, 3,316,177, 3,340,281, 3,351,552, 3,381,022, 3,433,744, 3,444,170, 3,467,668, 3,501,405, 3,542,680, 3,576,743, 3,632,511, 4,234,435, Re 26,433, y 6,165,235, y 7,238,650 y la solicitud de patente de Europa núm. 0355895 A.

Illustrative dispersants can also be post-treated by conventional methods by reaction with any of a variety of agents. These include boron compounds (such as boric acid), urea, thiourea, dimercaptothiadiazoles, carbon disulfide, aldehydes, ketones, carboxylic acids such as terephthalic acid, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitriles, epoxides and phosphorus compounds. In one embodiment the post-treated dispersant is borated. In one embodiment the post-treated dispersant is reacted with dimercaptothiadiazoles. In one embodiment the post-treated dispersant is reacted with phosphoric or phosphorous acid. In one embodiment the post-treated dispersant is reacted with terephthalic acid and boric acid (as described in US Publication No. 2009/0054278.

Dispersant viscosity modifiers (DVMs) are dispersants that provide dispersion and viscosity modification. Exemplary DVMs are made from polymers such as an olefin polymer (eg, ethylene propylene copolymer) and/or vinyl aromatic polymers (eg, polystyrene) that have been radically grafted with an ethylenically unsaturated carboxylic acid material, such as maleic anhydride that is functionalized with one or more amines and/or a pendant functional group that has sulfonate functionality. DVMs of this type are described, for example, in US Pat. 4,863,623; 5,264,140; 5,409,623; 6,107,257; 6,107,258; 6,117,825; United States publications no. 2012/0178656; 2012/0178659; 2009/0305923, and document no. WO 2016044262.

When present, the lubricant composition may include at least 0.01% by weight, or at least 0.1% by weight, or at least 0.5% by weight, or at least 1% by weight of dispersant and, in some embodiments, up to 20 wt%, or up to 15 wt%, or up to 10 wt%, or up to 6 wt% or up to 3 wt% dispersant.

D. Antiwear Agents

The lubricant composition optionally includes at least one antiwear agent. Examples of suitable antiwear agents for use herein include titanium compounds, tartrates, tartrimides, oil-soluble amine salts of phosphorous compounds, sulfurized olefins, metal dihydrocarbyl dithiophosphates (such as zinc dialkyl dithiophosphates (ZDDP)), phosphites (such as dibutyl phosphite), phosphonates, thiocarbamate-containing compounds, such as thiocarbamate esters, thiocarbamate amides, thiocarbamic ethers, alkylene-coupled thiocarbamates, and bis(S-alkyldithiocarbamyl) disulfides. The antiwear agent can in one embodiment include a tartrate or tartrimide, as described in US Publication Nos. 2006/0079413; 2006/0183647; and 2010/0081592. The tartrate or tartrimide may contain alkyl ester groups, where the sum of carbon atoms in the alkyl groups is at least 8. The antiwear agent may, in one embodiment, include a citrate as described in US publication no.

20050198894.

When present, the lubricating composition may include at least 0.01% by weight, or at least 0.1% by weight, or at least 0.5% by weight of anti-wear agent and, in some embodiments, up to 3%. by weight, or up to 1.5% by weight, or up to 0.9% by weight of antiwear agent.

In one embodiment, the lubricant composition is without or substantially free of phosphorus-containing antiwear agents. For example, phosphorus-containing antiwear agents are present, if present, in an amount that allows the lubricating composition to have no more than 0.15% by weight of phosphorus, or up to 1.1% by weight of phosphorus. , or up to 0.8% by weight of phosphorus. For example, the C3/6 mixed secondary ZDDPs may be present at up to 1.2 wt%, or up to 1 wt%, or up to 0.5 wt%.

E. Oil Soluble Titanium Compounds

The lubricating composition may include one or more oil-soluble titanium compounds that may function as anti-wear agents, friction modifiers, antioxidants, deposit control additives, or more than one of these functions. Examples of oil-soluble titanium compounds are described in US Pat. 7,727,943 and US publication no. 2006/0014651. Examples of oil-soluble titanium compounds include titanium (IV) alkoxides, such as titanium (IV) isopropoxide and titanium (IV) 2-ethylhexoxide. Said alkoxides can be formed from a monohydric alcohol, an adjacent 1,2-diol, a polyol or a mixture of these. The monohydric alkoxides can have from 2 to 16, or from 3 to 10 carbon atoms. In one embodiment, the titanium compound comprises the alkoxide of an adjacent 1,2-diol or polyol. Adjacent 1,2-diols include fatty acid monoesters of glycerol, where the fatty acid may be, for example, oleic acid. Other examples of oil-soluble titanium compounds include titanium carboxylates, such as titanium neodecanoate.

When present in the lubricant composition, the amount of oil-soluble titanium compounds is included as part of the antiwear agent.

F. Extreme Pressure (EP) Agents

The lubricant composition may include an extreme pressure agent. Extreme pressure agents that are soluble in oil include EP agents containing sulfur and chlorosulfide, dimercaptothiadiazole, or CS ² derivatives of dispersants (typically succinimide dispersants), which are derived from chlorinated hydrocarbon EP agents and phosphorous EP agents. Examples of such EP agents include chlorinated wax; sulfurized olefins (such as sulfurized isobutylene), hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazoles and oligomers thereof, organic sulfides and polysulfides, such as dibenzyl disulfide, bis-(chlorobenzyl) disulfide, tetrasulfide dibutyl, sulfurized oleic acid methyl ester, sulfurized alkylphenol, sulfurized dipentene, sulfurized terpene, and sulfurized Diels-Alder adducts; phosphosulfurized hydrocarbons, such as the reaction product of phosphorous sulfide with turpentine or methyl oleate; phosphorus esters, such as dihydrocarbon and trihydrocarbon phosphites, eg dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite; dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite, and polypropylene-substituted phenol phosphite; metal thiocarbamates, such as zinc dioctyldithiocarbamate and barium heptylphenol diacid; amine salts of alkyl and dialkyl phosphoric acids or derivatives including, for example, the amine salt of a reaction product of a dialkyldithiophosphoric acid with propylene oxide and subsequently further followed by reaction with P ² O ⁵ ; and mixtures of these. Some useful extreme pressure agents are described in US Pat. 3,197,405. When present, the lubricant composition may include at least 0.01% by weight, or at least 0.1% by weight, or at least 0.5% by weight of extreme pressure agent, and in some embodiments, up to 3 % by weight, or up to 1.5% by weight, or up to 0.9% by weight of the extreme pressure agent.

G. Foam inhibitors

The lubricant composition may include a foam inhibitor. Foam inhibitors that may be useful in the lubricant composition include polysiloxanes; copolymers of ethyl acrylate and 2-ethylhexyl acrylate and optionally vinyl acetate; demulsifiers including fluorinated polysiloxanes, trialkyl phosphates, polyethylene glycols, polyethylene oxides, polypropylene oxides, and (ethylene oxide-propylene oxide) polymers. H. Viscosity Modifiers

The lubricant composition may include a viscosity modifier. Viscosity modifiers (also sometimes referred to as viscosity index improvers or viscosity improvers) useful in the lubricant composition are generally polymers, including polyisobutenes, polymethacrylates (PMA) and polymethacrylic acid esters, diene polymers, polyalkylstyrenes , esterified styrene-maleic anhydride copolymers, hydrogenated alkenylarene-conjugated diene copolymers, and polyolefins also called olefin copolymers or OCPs. PMAs are prepared from mixtures of methacrylate monomers having different alkyl groups. Alkyl groups can be straight or branched chain groups containing from 1 to 18 carbon atoms. Most PMAs are viscosity modifiers as well as pour point depressants. In one embodiment, the viscosity modifier is a polyolefin comprising ethylene and one or more higher olefins, such as propylene.

When present, the lubricant composition may include at least 0.01% by weight, or at least 0.1% by weight, or at least 0.3% by weight, or at least 0.5% by weight of lubricant modifiers. polymeric viscosity modifiers and, in some embodiments, up to 10% by weight, or up to 5% by weight, or up to 2.5% by weight of polymeric viscosity modifiers.

I. Corrosion inhibitors and metal deactivators

The lubricating composition may include a corrosion inhibitor. Corrosion inhibitors/metal deactivators that may be useful in the illustrative lubricant composition include fatty amines, octylamine octanoate, condensation products of dodecenylsuccinic acid or anhydride and a fatty acid such as oleic acid with a polyamine, derivatives of benzotriazoles ( eg, tolyltriazole), 1,2,4-triazoles, benzimidazoles, 2-alkyldithiobenzimidazoles, and 2-alkyldithiobenzothiazoles.

J. Pour Point Depressants

The lubricant composition may include a pour point depressant. Pour point depressants that may be useful in the illustrative lubricant composition include polyalphaolefins, esters of maleic anhydride-styrene copolymers, polymethacrylates, polyacrylates, and polyacrylamides.

K. Friction Modifiers

The lubricant composition may include a friction modifier. Friction modifiers that may be useful in the illustrative lubricant composition include fatty acid derivatives, such as amines, esters, epoxides, fatty imidazolines, condensation products of carboxylic acids and polyalkylene polyamines, and amine salts of alkyl phosphoric acids. The friction modifier may be an ashless friction modifier. Such friction modifiers are those that typically do not produce sulfated ash when subjected to the conditions of ASTM D 874 (see AsTm D874 - 13a, "Standard Test Method for Sulfated Ash from Lubricating Oils and Additives", ASTM International, West Conshohocken, PA, 2013). An additive is referred to as "non-metal containing" if it does not contribute to the metal content of the lubricant composition. As used herein the term "fatty alkyl" or "fatty" in relation to friction modifiers means a carbon chain having from 8 to 30 carbon atoms, typically a straight carbon chain. The amount of the ashless friction modifier in a lubricant may be 0.1 to 3% by weight (or 0.12 to 1.2 or 0.15 to 0.8% by weight). The material can also be present in a concentrate, alone or with other additives and with a smaller amount of oil. In a concentrate, the amount of material can be two to ten times the above concentration amounts.

In one embodiment, the ashless friction modifier can be represented by the formula:

where D and D' are independently selected from -O-, >NH, >NR ²³ , an imide group formed by bringing groups D and D' together and forming an R ²¹ -N< group between two >C=O groups; E is selected from -R ²⁴ -OR ²⁵ -, >CH ² , >CHR ²⁶ , >CR ²⁶ R ²⁷ , >C(OH)(CO ² R ²² ), >C(CO ² R ²² ) ² , and >^CHOR28; where R ²⁴ and R ²⁵ are independently selected from >CH ² , >CHR ²⁶ , >CR ²⁶ R ²⁷ , >C(OH)(CO ² R ²² ), and >CHOR ²⁸ ; q is from 0 to 10, with the proviso that when q=1, E is not >CH ² , and when n=2, both E's are not >CH ² ; p is 0 or 1; R ²¹ is independently hydrogen or a hydrocarbyl group, which typically contains from 1 to 150 carbon atoms, with the proviso that when R21 is hydrogen, p is 0 and q is greater than or equal to 1; R22 is a hydrocarbyl group, typically containing from 1 to 150 carbon atoms; R23, R24, R25, R26 and R27 are independently hydrocarbyl groups; and R28 is hydrogen or a hydrocarbyl group, containing 1 to 150 carbon atoms, or 4 to 32 carbon atoms, or 8 to 24 carbon atoms. In certain embodiments, the hydrocarbyl groups R23, R24 and R25 can be linear or predominantly linear alkyl groups.

In certain embodiments, the ashless friction modifier is a fatty ester, amide, or imide of various hydroxycarboxylic acids, such as tartaric acid, malic acid, lactic acid, glycolic acid, and mandelic acid. Examples of suitable materials include tartaric acid di(2-ethylhexyl) ester (i.e., di(2-ethylhexyl) tartrate), di(C8-Ci0) tartrate, di(Ci2-i5) tartrate, dioleyl, oleyltartrimide and oleylmaleimide.

In certain embodiments, the suitable ashless friction modifier may be chosen from long chain fatty acid derivatives of fatty amines, fatty esters or epoxides; fatty imidazolines, such as condensation products of carboxylic acids and polyalkylene polyamines; amine salts of alkyl phosphoric acids; fatty alkyl tartrates; fatty alkyl tartrimides; fatty alkyl tartramides; fatty phosphonates; fatty phosphites; borated phospholipids, borated fatty epoxides; glycerol esters; borated glycerol esters; fatty amines; alkoxylated fatty amines; borated fatty alkoxylated amines; hydroxylated and polyhydroxy fatty amines including hydroxy tertiary fatty amines; hydroxyalkylamides; fatty acid metal salts; metal salts of alkyl salicylates; fatty oxazolines; fatty alcohol ethoxylates; condensation products of carboxylic acids and polyalkylene polyamines; or reaction products of fatty carboxylic acids with guanidine, aminoguanidine, urea, or thiourea and salts thereof.

Friction modifiers can also encompass materials such as sulfur fatty compounds and olefins, sunflower oil or soybean oil monoester of a polyol and an aliphatic carboxylic acid.

In another embodiment, the friction modifier can be a long chain fatty acid ester. In another embodiment, the long chain fatty acid ester may be a monoester and in another embodiment the long chain fatty acid ester may be a triglyceride.

Molybdenum compounds are also known as friction modifiers. The illustrative molybdenum compound contains no ligands or dithiocarbamate moieties.

Nitrogen-containing molybdenum materials include molybdenum-amine compounds, as described in US Pat. 6,329,327 and organomolybdenum compounds made from the reaction of a molybdenum source, fatty oil, and a diamine as described in US Pat. 6,914,037. Other molybdenum compounds are described in US publication no.

20080280795. Molybdenum amine compounds can be obtained by reacting a compound containing a hexavalent molybdenum atom with a primary, secondary or tertiary amine represented by the formula NR29R30R31, where each of R29, R30 and R31 is independently hydrogen or a hydrocarbyl group of 1 to 32 carbon atoms and wherein at least one of R29, R30 and R31 is a hydrocarbyl group of 4 or more carbon atoms or represented by the formula:

where R32 represents a chain hydrocarbyl group having 10 or more carbon atoms, s is 0 or 1, R33 and/or R34 represents a hydrogen atom, a hydrocarbyl group, an alkanol group or an alkylamino group having 2 to 4 carbon atoms, and when s = 0, both R33 and R34 are not hydrogen atoms or hydrocarbon groups. Specific examples of suitable amines include monoalkyl (or alkenyl)amines, such as tetradecylamine, stearylamine, oleylamine, beef tallow alkylamine, hardened beef tallow alkylamine, and soybean oil alkylamine; dialkyl (or alkenyl)amines, such as N-tetradecylmethylamine, N-pentadecylmethylamine, N-hexadecylmethylamine, N-stearylmethylamine, N-oleylmethylamine, N-cocoylmethylamine, N-beef tallow alkylmethylamine, hardened beef tallow N-methylamine, N- soybean oil alkylmethylamine, ditetradecylamine, dipentadecylamine, dihexadecylamine, distearylamine, dioleylamine, bis(2-hexyldecyl)amine, bis(2-octyldodecyl)amine, bis(2-decyltetradecyl)amine, beef tallow dialkylamine, beef tallow dialkylamine hardened beef and soybean oil dialkylamine; and trialk(en)ylamines, such as tetradecyldimethylamine, hexadecyldimethylamine, octadecyldimethylamine, beef tallow alkyldimethylamine, hardened beef tallow alkyldimethylamine, soybean oil alkyldimethylamine, dioleylmethylamine, tritetradecylamine, tristearylamine and trioleylamine. Suitable secondary amines have two alkyl (or alkenyl) groups with 14 to 18 carbon atoms.

Examples of the hexavalent molybdenum atom-containing compound include molybdenum trioxides or hydrates thereof (MoO ³ .nH ² O), molybdenum acid (H ² MoO ⁴ ), alkali metal molybdates (Q ² MoO ⁴ ) wherein Q represents an alkali metal, such as sodium or potassium, ammonium molybdates ((NH4) ² MoO ⁴ or heptamolybdate (NH ⁴ )6[Mo ⁷ O ²⁴ ].4H ² O), MoOCU, MoO ² Ch, MoO ² Br ² , Mo ² O ³ Cl ⁶ and the like. Molybdenum trioxides or hydrates, molybdenum acid, alkali metal molybdates and ammonium molybdates are often suitable due to their availability. In one embodiment, the lubricant composition comprises a molybdenum amine compound.

Other suitable organomolybdenum compounds may be the reaction products of fatty oils, monoalkylated alkylenediamines and a source of molybdenum. Materials of this type are generally made in two stages, a first stage involving the preparation of an aminoamide/glyceride mixture at high temperature and a second stage involving the incorporation of molybdenum.

Examples of fatty oils that can be used include cottonseed oil, peanut oil, coconut oil, linseed oil, palm kernel oil, olive oil, corn oil, palm oil, castor oil, rapeseed (low or high erucic acid content), soybean oil, sunflower oil, herring oil, sardine oil and tallow. These fatty oils are generally known as glyceryl esters of fatty acids, triacylglycerols, or triglycerides.

Examples of some monoalkylated alkylenediamines that can be used include methylaminopropylamine, methylaminoethylamine, butylaminopropylamine, butylaminoethylamine, octylaminopropylamine, octylaminoethylamine, dodecylaminopropylamine, dodecylaminoethylamine, hexadecylaminopropylamine, hexadecylaminoethylamine, octadecylaminopropylamine, octadecylaminoethylamine, isopropyloxypropyl-1,3-diaminopropane, and octyloxypropyl-1,3-diaminopropane. Monoalkylated alkylenediamines derived from fatty acids can also be used. Examples include coconut N-alkyl-1,3-propanediamine (Duomeen ^® C), bait oil N-alkyl-1,3-propanediamine (Duomeen ^® T), and N-oleyl-1,3-propanediamine (Duomeen ^® O), all commercially available from Akzo Nobel. Molybdenum sources for incorporation into the fatty oil/diamine complex are generally oxygen-containing molybdenum compounds including, similarly to the above, ammonium molybdates, sodium molybdate, molybdenum oxides, and mixtures of these. A suitable molybdenum source comprises molybdenum trioxide (MoO ³ ).

Commercially available nitrogen-containing molybdenum compounds include, for example, Sakuralube ^® 710 available from Adeka which is a molybdenum amine compound, and Molyvan ^® 855, available from RT Vanderbilt.

The nitrogen-containing molybdenum compound may be present in the lubricant composition from 0.005 to 2% by weight of the composition, or from 0.01 to 1.3% by weight, or from 0.02 to 1.0% by weight. of the composition. The molybdenum compound can provide 0 to 1000 ppm, or 5 to 1000 ppm, or 10 to 750 ppm, 5 ppm to 300 ppm, or 20 ppm to 250 ppm of molybdenum to the lubricant composition.

L. Demulsifiers

Demulsifiers useful in the present disclosure include trialkylphosphates, and various polymers and copolymers of ethylene glycol, ethylene oxide, propylene oxide, or mixtures thereof.

M. Seal Expansion Agents

Seal blowing agents include sulfolene derivatives such as Exxon Necton-37™ (FN 1380) and Exxon Mineral Seal Oil™ (FN 3200).

N. TBN enhancers

Useful TBN enhancers are the anthranilate ester (anthranilic acid esters) as described, for example, in US publication no. 20140187458, such as decyl anthranilate.

Example lubricant compositions

An engine lubricant in different embodiments may have a composition as illustrated in Table 1. All additives are expressed on an oil-free basis.

The illustrative N-alkylated dianiline compound tends to be more effective in low magnesium lubricant compositions. In the lubricant composition, the ratio of calcium to magnesium by weight can be at least 90:10 and, in one embodiment, up to 10:90. Calcium can be provided by overbased detergents, such as calcium sulfonates, as discussed above. In one embodiment, the lubricant composition includes less than 500 ppm magnesium, or less than 200 ppm magnesium, or less than 100 ppm magnesium.

Table 1: Example of lubricant composition

Use of the lubricant composition

The lubricant composition described in the present description can be used to reduce the formation of deposits in an internal combustion engine. The lubricant composition described in the present description can also be used to lubricate an internal combustion engine.

The end use of the lubricant composition described herein includes use as a cylinder lubricant for an internal combustion engine, such as in a passenger car or a heavy, medium or light duty diesel vehicle, but may also find use as a motor oil for 2-stroke marine diesel engines, small engines such as motorcycles and 2-stroke oil engines, as a transmission lubricant, including gear and automatic transmission oils, and for other industrial oils, such as hydraulic lubricants.

An illustrative method (not covered by the present invention) for lubricating a mechanical device, such as a passenger car engine cylinder, includes supplying the illustrative lubricant composition to the device.

Generally, the lubricant composition is added to the internal combustion engine's lubrication system, which then supplies the lubricant composition to the cylinder of the engine, during its operation.

The internal combustion engine may be a gasoline fueled engine, a diesel fueled engine, such as a 2-stroke marine diesel engine, or a natural gas fueled engine, a gasoline/alcohol blend fueled engine, or a diesel engine. fueled with biodiesel. The internal combustion engine can be a 2-stroke or 4-stroke engine.

The internal combustion engine may be a passenger car internal combustion engine. The passenger car internal combustion engine may have a reference mass not exceeding 2610 kg. The passenger car engine can run on unleaded gasoline. Unleaded petrol is well known in the art and is defined by British Standard BS EN 228:2008 (entitled "Automotive Fuels - Unleaded Petrol - Requirements and Test Methods"). The internal combustion engine may be a heavy-duty diesel internal combustion engine. The heavy-duty internal combustion diesel engine may have a "technically permissible maximum laden mass" greater than 3,500 kg. The engine can be a compression ignition engine or a positive ignition natural gas (NG) or LPG (Liquefied Petroleum Gas) engine.

The lubricant composition may be suitable for use as a cylinder lubricant regardless of the sulfur, phosphorus, or sulfated ash (ASTM D-874) content of the fuel. The sulfur content of the lubricant composition, which is particularly suitable for use as an engine lubricant, may be 1% by weight or less, or 0.8% by weight or less, or 0.5% by weight. or less, or 0.3% by weight or less. In one embodiment, the sulfur content may be in the range of 0.001 wt% to 0.5 wt%, or 0.01 wt% to 0.3 wt%. The phosphorus content may be 0.2% by weight or less, 0.12% by weight or less, 0.1% by weight or less, 0.085% by weight or less, 0.08% by weight or less. weight or less, or even 0.06% by weight or less, 0.055% by weight or less, or 0.05% by weight or less. In one embodiment, the phosphorus content can be from 100 ppm to 1000 ppm, or from 200 ppm to 600 ppm. The sulfated ash content may be 2% by weight or less, or 1.5% by weight or less, or 1.1% by weight or less, or 1% by weight or less, or 0. 8% by weight or less, or 0.5% by weight or less, or 0.4% by weight or less. In one embodiment the sulfated ash content may be from 0.05 wt% to 0.9 wt%, or from 0.1 wt% to 0.2 wt% or 0.45 wt%.

Without intending to limit the scope of the illustrative embodiment, the following examples illustrate the preparation and evaluation of example compounds.

examples

All reagents and additives are expressed on an oil-free basis.

Example 1: Synthesis of 4,4'-cyclohexylmethylenedianiline (CY-MDA)

4,4'-methylenedianiline (MDA) (1 eq.), cyclohexanone (2.1 eq.), and acetic acid (0.05 eq.) are charged to a flask with toluene and heated to reflux with removal of water. After imine formation is complete, residual toluene and acetic acid are removed in vacuo. The resulting imine is dissolved in methanol and cooled to less than 10°C using an ice bath. Sodium borohydride (2.2 eq.) is added in portions, while keeping the reaction temperature below 15°C. The solution is then allowed to warm to room temperature and stirred for a further 2 hours. After the reduction is complete, the mixture is quenched with water and the product is extracted with ethyl acetate. No further purification is needed. The reaction results in the formation of compound A-1 shown in TABLE 2.

Example 2: Synthesis of 4,4'-2-ethylhexylmethylenedianiline (EHL-MDA)

The process of Example 1 is repeated, using 2-ethylhexanal (2.1 eq.) instead of cyclohexanone as the ketone. The reaction results in the formation of compound A-2 shown in TABLE 2:

Using the method of Examples 1 and 2, with the product being collected by filtration or extraction with ethyl acetate, the products shown in TABLE 2 are formed using the following amines and ketones/aldehydes:

Table 2: Diamine Compounds

Example 3: Lubricant compositions

The N,N'-dialkylmethylenedianiline compounds prepared according to Examples 1 and 2 are evaluated in various formulations.

A. Superior lubricants for internal combustion engines

Lubricant compositions suitable as 5W-30 motor lubricants are prepared using a reference formulation as shown in TABLE 3. All concentrations are oil-free (ie, on an active basis).

Table 3: Reference lubricant composition B1

The alkylated dianilines from Examples 1 and 2 are added to the reference composition, as shown in TABLE 4, to form lubricant compositions L1 and L2, respectively.

Table 4: Lubricating oil composition formulations

Lubricant compositions B1, L1 and L2 are evaluated in the following bench oxidation tests:

1. Impact on thin film antioxidant capacity: Pressure Differential Scanning Calorimeter (PDSC) test measures the oxidative induction time (OIT) of compositions. This is a standard test procedure in the lubricating oil industry, based on CEC L-85 T-99. In this test, the lubricant composition is heated to an elevated temperature, typically about 25°C below the average decomposition temperature for the sample being tested (in this case, 215°C at 690 kPa), and measured. the moment when the composition begins to decompose. The longer the test time, expressed in minutes, the better the oxidative stability of the composition and the additives present in it.

2. Deposits ( MHT TEOST): Determined in accordance with ASTM D7097 - 09. The MHT TEOST method evaluates deposit formation at temperatures closely related to those in the piston ring area in reciprocating engines. An organometallic catalyst mixture of a predetermined concentration equivalent to about 8.5 g is circulated for 24 hours on a wire-wound reservoir rod at 285°C together with 10 ml/min of air. The reservoir rod is weighed before the test and after the test. All post-test deposits collected after the stick was washed along with the stick deposits equal the total deposits. In the MHT TEOST, a lower amount of deposit indicates better performance in deposit control.

The results obtained are shown in TABLE 5.

Table 5: Oxidation results for lubricating oil composition formulations

The results shown in TABLE 5 suggest that the lubricant compositions (L1 and L2) (for example, an internal combustion engine lubricant) containing the alkylated dianilines of Examples 1 and 2 provide exceptional antioxidant performance, as well as also an unexpected deposit control performance compared to the reference formulation (B1).

B. Low Phosphorus Internal Combustion Engine Lubricants

Lubricant compositions suitable as 5W-30 motor lubricants are prepared using a reference formulation (B2) as shown in TABLE 6. All concentrations are on non-oil (ie active) bases.

Table 6: Reference lubricant composition B2

Diamines A-1, A-3 and A-4 are added to reference composition B1 in the amounts shown in TABLE 7, to form lubricant compositions L3, L4 and L5. Another lubricant composition (C1) is prepared with an amine antioxidant.

Table 7: Lubricating oil composition formulations

Lubricant compositions B2, L3, L4, L5 and C1 are evaluated in bench oxidation tests, as described above. The results obtained are shown in TABLE 8.

TABLE 8: Oxidation results for lubricating oil composition formulations

The results shown in TABLE 8 suggest that illustrative lubricant compositions (L3, L4, and L5) (eg, an internal combustion engine lubricant) containing the alkylated dianilines A-1, A-3, and A-4 they provide exceptional antioxidant performance, as well as unexpected deposit control performance compared to the reference formulation (B2), indicating that the exemplary alkylated dianilines are very efficient in low phosphorus formulations. Furthermore, 0.5% of these alkylated dianilines provide a much more significant performance improvement over the reference formulation in the PDSC and MHT TEOST tests than the addition of an additional 0.5% of amine antioxidant (C1).

C. Lubricants for internal combustion engines

Lubricant compositions suitable as 15W-40 motor lubricants are prepared using a reference formulation (B3) as shown in TABLE 9. All concentrations are oil-free (ie, on an active basis).

Table 9: Reference lubricant composition B3

Diamines A-1 and A-2 are added to reference composition B3 in the amounts shown in TABLE 10, to form lubricant compositions L6 and L7.

Table 10: Lubricating oil composition formulations

Lubricant compositions B3, L6 and L7 are evaluated in bench oxidation tests, as described above. The results obtained are shown in TABLE 11.

TABLE 11: Oxidation results for lubricating oil composition formulations

The results shown in TABLE 11 suggest that illustrative lubricant compositions (L6 and L7) (eg, an internal combustion engine lubricant) containing the alkylated dianilines A-1 and A-2 provide exceptional antioxidant performance, as well as unexpected deposit control performance when compared to the reference formulation (B3), indicating that the illustrative alkylated dianilines are very effective in these formulations.

As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense, which is well known to those skilled in the art. Specifically, it refers to a group that has a carbon atom that is directly attached to the rest of the molecule and that is predominantly hydrocarbon in character. By predominantly hydrocarbon character is meant that at least 70% or at least 80% of the atoms in the substituent are hydrogen or carbon.

Examples of hydrocarbyl groups include:

(i) hydrocarbon substituents, that is, aliphatic (eg, alkyl or alkenyl), alicyclic (eg, cycloalkyl, cycloalkenyl), and aromatic, aliphatic, and alicyclic-substituted aromatic substituents, as well as cyclic substituents wherein the ring is completed through another portion of the molecule (eg, two substituents together form a ring);

(ii) substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the predominant hydrocarbon nature of the substituent (for example, halo (especially chlorine and fluorine), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso and sulfoxy);

(iii) heterosubstituents, ie substituents which, while predominantly hydrocarbon in character, may contain something other than carbon in a ring or chain otherwise composed of carbon atoms.

Representative alkyl groups include n-butyl, isobutyl, sec-butyl, n-pentyl, amyl, neopentyl, n-hexyl, nheptyl, secondary heptyl, n-octyl, secondary octyl, 2-ethylhexyl, n-nonyl, secondary nonyl, undecyl, secondary undecyl, dodecyl, secondary dodecyl, tridecyl, secondary tridecyl, tetradecyl, secondary tetradecyl, hexadecyl, secondary hexadecyl, stearyl, icosyl, docosyl, tetracosyl, 2-butyloctyl, 2-butyldecyl, 2-hexyloctyl, 2-hexidyl, 2-octyldecyl, 2-hexyldodecyl, 2-octyldodecyl, 2-decyltetradecyl, 2-dodecylhexadecyl, 2-hexyldecyloctyldecyl, 2-tetradecyloctyldecyl, branched monomethylisostearyl, and the like.

Representative aryl groups include phenyl, tolyl, xylyl, cumenyl, mesityl, benzyl, phenethyl, styryl, cinnamyl, benzhydryl, trityl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, heptylphenyl, octylphenyl, nonylphenyl, decylphenyl, undecylphenyl, dodecylphenyl, benzylphenyl , styrenated phenyl, p-cumylphenyl, a-naphthyl, p-naphthyl groups and mixtures of these.

Heteroatoms include sulfur, oxygen, nitrogen, and encompass substituents such as pyridyl, furyl, thienyl, and imidazolyl. In general, no more than two, and in one embodiment, no more than one, non-hydrocarbon substituents will be present for every ten carbon atoms in the hydrocarbyl group. In some embodiments, there are no non-hydrocarbon substituents on the hydrocarbyl group.

Representative aliphatic groups may contain 4 to 14 carbon atoms, 6 to 12 carbon atoms, or 8 to 10 carbon atoms. Examples of suitable alkyl groups include butyl, isobutyl, pentyl, isopentyl, neopentyl, hexyl, amyl, heptyl, octyl, isooctyl, 2-ethylhexyl, nonyl, decyl, isodecyl, undecyl, dodecyl, 2-propylheptyl, tridecyl, isotridecyl, tetradecyl , 4-methyl-2-pentyl, propylheptyl, and combinations of these.

Hydrocarbylene groups are the divalent equivalents of hydrocarbyl groups, such as alkylene groups. Unless otherwise indicated, each chemical or composition referenced herein is to be construed as a commercial grade material that may contain the isomers, by-products, derivatives, and other similar materials typically understood to be are present in the commercial grade. However, the amount of each chemical component is presented excluding any solvent or diluent oil, which may usually be present in the commercial material, unless otherwise indicated. It is to be understood that the upper and lower limits of amount, range, and ratio set forth herein may be combined independently. Similarly, the ranges and amounts for each element of the invention may be used in conjunction with ranges or amounts for any of the other elements.

Claims (15)

1. A lubricant composition comprising: a) an oil of lubricating viscosity; b) at least 0.1% by weight of an N-alkylated dianiline compound; c) at least 0.1% by weight of an ashless antioxidant that is selected from a diarylamine antioxidant, a phenolic antioxidant and combinations of these, and d) at least 0.01% by weight of an overbased calcium detergent; wherein the lubricant composition comprises less than 0.15 weight percent phosphorus; Y wherein the N-alkylated dianiline is an N,N'-alkylated dianiline compound represented by the formula:

wherein R1 and R2 are independently selected from alkyl groups of 1 to 24 carbon atoms, said alkyl groups are selected from acyclic alkyl groups, cyclic alkyl groups, and combinations thereof. 2. The lubricant composition according to claim 1, wherein the lubricant composition has a TBN of at least 4 mg KOH/g, measured according to ASTM D-2896. 3. The lubricant composition according to claim 1 or 2, wherein the N-alkyl group is a cyclohexyl group. 4. The lubricant composition according to any preceding claim, wherein the N-alkylated dianiline compound is at least 0.15% by weight, or at least 0.2% by weight, or at least 0.4% by weight of the lubricant composition or is up to 4.0 percent by weight of the lubricant composition, or up to 3 percent by weight, or up to 1.5 percent by weight, or up to 1.2 percent by weight of the composition lubricant. 5. The lubricant composition according to any preceding claim, wherein the N-alkylated dianiline compound is selected from the group consisting of:

and mixtures of these. 6. The lubricant composition according to claim 5, wherein the N-alkylated dianiline compound is selected from 4,4'-2-ethylhexylmethylenedianiline, 4,4'-cyclohexylmethylenedianiline, and mixtures thereof. 7. The lubricating composition according to any preceding claim, wherein the oil of lubricating viscosity is at least 40 weight percent of the lubricating composition. 8. The lubricant composition according to any preceding claim, wherein the ashless antioxidant is at least 0.2% by weight, or at least 0.4% by weight, or at least 0.6% by weight, or up to 4% by weight, or up to 1.2% by weight, or up to 1% by weight of the lubricant composition. 9. The lubricant composition according to any preceding claim, wherein a ratio of the ashless antioxidant to the N-alkyldianiline compound is from 20:1 to 1:20 and/or wherein the ratio of calcium to magnesium in the lubricant composition , by weight, is at least 9:10. 10. The lubricant composition according to any preceding claim, wherein the ashless antioxidant comprises a phenolic ester and a diarylamine and, optionally, a sulfurized olefin. 11. The lubricant composition according to any preceding claim, wherein the overbased calcium detergent is selected from sulfonates, non-sulfur containing phenates, sulfur containing phenates, salixarates, salicylates, mixtures of these and borated equivalents thereof. 12. The lubricant composition according to any preceding claim, wherein the overbased calcium detergent is at least 0.1% by weight, or at least 0.5% by weight, or up to 3% by weight, or up to 2% by weight of the lubricant composition. 13. The lubricant composition according to any preceding claim, further comprising a polyolefin succinimide dispersant, wherein the polyolefin group has a number average molecular weight of at least 300. 14. Use of the lubricant composition according to any of claims 1-13 to reduce the formation of deposits in an internal combustion engine. 15. Use of the lubricant composition according to any of claims 1-13 to lubricate an internal combustion engine.