Compositions with improved performance containing alkylated diphenylamine

Abstract

The present invention relates to a composition comprising an alkylated diphenylamine of structural formulas (I), (II), (III) and (IV), to industrial products comprising mixtures of alkylated diphenylamines, such as additive blends, engine oils and polymer compositions, and to the use of said mixtures as additives in industrial products such as additive blends, engine oils and polymer compositions. Wherein R is a branched C4-C 16 alkyl, and wherein the total amount of tetraalkylated diphenylamine of structural formula (IV) is in the range of 0.20% to 3.5% by weight, based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) in the composition.

Description

Technical Field

[0001] The present invention relates to a compound comprising an alkylated diphenylamine. The present invention also relates to industrial products comprising such a composition and the use of such a composition as an additive in industrial products. Background Art

[0002] Lubricants (such as lubricants for various machines) are prone to oxidative deterioration during storage, transportation, and use, especially when such lubricants are exposed to high temperatures and iron-catalyzed environments that greatly promote their oxidation. If not controlled, this oxidation will promote the formation of corrosive acidic products, sludge, varnish, resins, and other oil-insoluble products, and may result in the loss of the specified physical and tribological properties of the lubricant. Therefore, a common practice is to add antioxidants to the lubricant to at least to some extent prevent oxidation and extend its service life. Lubricant compositions containing various diarylamine or phenol compounds as antioxidants are well known in the art.

[0003] WO 2007 / 100726 A2 discloses a lubricant composition comprising: at least one lubricating oil selected from the group consisting of natural and synthetic lubricating base oils; at least one first antioxidant which may be an alkylated diphenylamine; and at least one sulfur-containing alkylated phenol as a second antioxidant, wherein a synergistic effect on oxidation stability was observed when the first and second antioxidants were added to the lubricant.

[0004] However, it can be seen that a disadvantage of this method is that in order to improve the oxidation stability of engine oil, a new class of additives (i.e., sulfur-containing alkylated phenols) must be added to the engine oil, which not only increases the complexity of the fully formulated engine lubricant again, but also increases its production cost.

[0005] In addition, the specifications of engine oil are becoming increasingly strict in terms of performance requirements, and new formulations are being developed to meet these new specifications. Many of the additives contained in engine oil are corrosive to lead. It is difficult for formulators to meet the current engine oil specifications by adopting certain beneficial additives while also meeting the lead corrosion specifications. For example, some components in formulated engine oil that cause lead corrosion include certain detergents, antiwear additives, friction modifiers, and antioxidants. Many such required additive chemicals have been disqualified from use because they cause the engine oil formulation to not meet the industry specifications for lead corrosion limits.

[0006] WO 2004 / 015043 A1 discloses an engine oil which contains certain 1,2,4-triazole metal deactivators that are especially non-corrosive to lead. However, it must also be seen that a disadvantage of this method is that a more complex chemical additive must be added to the engine oil, which usually already contains a complex mixture of additives such as antioxidants, antiwear additives, dispersants, detergents, antifoam additives, viscosity index improvers, copper passivators, rust inhibitors, pour point depressants, demulsifiers, and friction improvers. Thus, this method not only increases the complexity of the fully formulated engine lubricant, but also increases its production cost. Summary of the Invention

[0007] Technical Problem

[0008] Accordingly, an object of the present invention is to overcome the disadvantages of the background art associated with compositions for improving the performance of industrial products, such as engine oils, especially with respect to the oxidative stability of said compositions, and preferably also with respect to the resistance of said compositions to lead corrosion.

[0009] In particular, an object of the present invention is to provide a composition which, when added to a base oil as a single additive or as a component in a so-called "additive package" to form a fully formulated engine oil, or which improves the performance of an engine oil, especially with respect to oxidative stability and preferably also with respect to resistance to lead corrosion.

[0010] More preferably, an object of the present invention is to provide a composition which, when added to a base oil as a single additive or as a component in an additive package to form a fully formulated engine oil, or when already present in the form of a fully formulated engine oil, produces a favorable combination of properties of high oxidative stability and good resistance to lead corrosion.

[0011] Technical Solution

[0012] The independent claims contribute to solving at least one, preferably more than one, of the above objects. The dependent claims provide preferred embodiments that contribute to solving at least one of the said objects at least in part.

[0013] The solution to solving at least one of the objects of the present invention is made by Example 1 of the composition, which composition contains alkylated diphenylamines of structural formulas (I), (II), (III), and (IV):

[0014]

[0015] wherein R is a branched C4-C 16an alkyl group, and wherein the total amount of the tetraalkylated diphenylamine of structural formula (IV) is in the range from 0.20% to 3.5% by weight, more preferably in the range from 0.21% to 3.3% by weight, and even more preferably in the range from 0.22% to 3.1% by weight, in each case based on the total amount of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) in the composition.

[0016] The lines connecting to the residue R in structural formulas (I), (II), (III) and (IV) indicate that this residue R can be connected to any carbon atom of the benzene ring (i.e., ortho, meta or para position). Thus, the alkylated diphenylamine of structural formula (I) represents a monosubstituted diphenylamine derivative, the alkylated diphenylamine of structural formula (II) represents a disubstituted diphenylamine derivative, the alkylated diphenylamine of structural formula (III) represents a trisubstituted diphenylamine derivative, and the alkylated diphenylamine of structural formula (IV) represents a tetrasubstituted diphenylamine derivative.

[0017] Additives in the form of mixtures of alkylated diphenylamines of structural formulas (I), (II) and (III) for lubricants are known from the prior art. The additives are used as antioxidants to improve the oxidation stability of lubricants (such as engine oils). However, it has now surprisingly been found that by ensuring that these compositions contain a precisely defined amount of the tetraalkylated diphenylamine having structural formula (IV), an improvement in the performance of engine oils containing such additives with respect to oxidation stability can be achieved. Particularly surprisingly, by ensuring that these compositions contain a precisely defined amount of the tetraalkylated diphenylamine, the resistance to lead corrosion can also be increased.

[0018] The composition according to the invention can be prepared by: providing a mixture of alkylated diphenylamines of structural formulas (I), (II) and (III); and supplementing the mixture with the required amount of the tetraalkylated diphenylamine having structural formula (IV).

[0019] A method for producing alkylated diphenylamines of structural formulas (I), (II) and (III) is for example disclosed in US 6,315,925 B1. Here, diphenylamine is reacted with an olefin in the presence of acidic clay as a catalyst. For the preparation of the preferred nonylalkylated diphenylamine, in which R represents a branched residue having the formula -C9H 19 diphenylamine can be alkylated with an excess of nonene or a mixture of isononenes in the presence of 2.0% to 25.0% by weight of acidic clay, based on diphenylamine, and in the absence of inorganic or organic acids in the reaction mixture, as shown for example in Example 1 of US 6,315,925 B1.

[0020] An alkylated diphenylamine having the structural formula (IV) (e.g., tetra-nonyl diphenylamine) can be produced by reacting diphenylamine with an excess of an olefin (e.g., nonene in the case of tetra-nonyl diphenylamine) at a reaction temperature between 140 °C and 155 °C under atmospheric pressure for a reaction time of 4 weeks. From the reaction mixture thus obtained, which contains mono-substituted, di-substituted, tri-substituted, and tetra-substituted diphenylamines, the tetra-substituted diphenylamine having the structural formula (IV) can be further enriched, for example, by distillation. With the distillate thus obtained, which contains an enriched content of the alkylated diphenylamine having the structural formula (IV), the content of this isomer in a given mixture of alkylated diphenylamines having the structural formulas (I), (II), and (III) can be adjusted by adding an appropriate amount of the distillate to the given mixture.

[0021] In Example 2 of the composition according to the invention, the composition is designed according to Example 1 thereof, wherein the total amount of the mono-alkylated diphenylamine of structural formula (I) is in the range of 10 wt% to 35 wt%, more preferably in the range of 13 wt% to 30 wt%, and even more preferably in the range of 16 wt% to 25 wt%, in each case based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) in the composition.

[0022] In Example 3 of the composition according to the invention, the composition is designed according to Example 1 or 2 thereof, wherein the total amount of the di-alkylated diphenylamine of structural formula (II) is in the range of 60 wt% to 85 wt%, more preferably in the range of 65 wt% to 82 wt%, and even more preferably in the range of 70 wt% to 79 wt%, in each case based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) in the composition.

[0023] In Example 4 of the composition according to the invention, the composition is designed according to any one of Examples 1 to 3 thereof, wherein the total amount of the tri-alkylated diphenylamine of structural formula (III) is in the range of 1 wt% to 10 wt%, more preferably in the range of 2 wt% to 8 wt%, and even more preferably in the range of 3 wt% to 6 wt%, in each case based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) in the composition.

[0024] In Example 5 of the composition according to the invention, the composition is designed according to any one of Examples 1 to 4 thereof, wherein the composition contains less than 1 wt%, preferably less than 0.5 wt%, and more preferably less than 0.1 wt% of the one having the structural formula C 12 H 11The non-alkylated diphenylamine of N, in each case based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) in the composition.

[0025] In Example 6 of the composition according to the invention, the composition is designed according to any one of Examples 1 to 5 thereof, wherein the residue R is an alkyl group having 1 to 20 carbon atoms, which may be branched or straight-chain, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, isomers of the foregoing (such as tert-butyl, 2-ethylhexyl and similar groups) and mixtures of the foregoing.

[0026] In Example 7 of the composition according to the invention, the composition is designed according to Example 6 thereof, wherein the residue R has the formula -C9H 19 branched alkyl.

[0027] In Example 8 of the composition according to the invention, the composition is designed according to Example 7 thereof, wherein in addition to the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV), the composition further contains less than 1% by weight, preferably less than 0.5% by weight, and even more preferably less than 0.1% by weight of an alkylated diphenylamine carrying at least one alkyl R', and the alkyl R' is not a branched alkyl having the formula -C9H 19 branched alkyl, in each case based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) in the composition.

[0028] In Example 9 of the composition according to the invention, the composition is designed according to any one of Examples 1 to 8 thereof, wherein at least one of the following conditions (α1) to (α7) is satisfied, preferably all of the following conditions (α1) to (α6):

[0029] (α1) The kinematic viscosity of the composition (measured at a temperature of 40 °C according to ASTM D 445) is in the range of 100 to 1000 cSt, more preferably in the range of 200 to 900 cSt, and more preferably in the range of 450 to 650 cSt;

[0030] (α2) The Gardner colour of the composition (measured according to ASTM D 1544) is less than 15 Gardner, preferably less than 10 Gardner, and more preferably less than 5 Gardner;

[0031] (α3) The water content of the composition (determined according to ASTM E 203) is less than 0.1% by weight, preferably less than 0.05% by weight, and more preferably less than 0.01% by weight;

[0032] (α4) The nitrogen content of the composition (determined according to ASTM D 2896) ranges from 3.2% to 3.8% by weight, preferably from 3.3% to 3.7% by weight, and more preferably from 3.4% to 3.9% by weight;

[0033] (α5) The specific gravity of the composition (determined according to ASTM D 1298 at a temperature of 25 °C) ranges from 0.930 to 0.980, preferably from 0.935 to 0.975, and more preferably from 0.940 to 0.970;

[0034] (α6) The total base number (TBN) of the composition (determined according to ASTM D 2896) ranges from 125 to 160 mg KOH / g, preferably from 130 to 150 mg KOH / g, and more preferably from 135 to 145 mg KOH / g.

[0035] In Example 10 of the composition according to the invention, the composition is designed according to any one of Examples 1 to 9 thereof, wherein the total amount of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV), preferably wherein R is a branched residue having the formula -C9H 19 The total amount of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) is at least 98% by weight, more preferably at least 98.5% by weight, and even more preferably at least 99% by weight, in each case based on the total weight of the composition.

[0036] In Example 11 of the composition according to the invention, the composition is designed according to any one of Examples 1 to 10 thereof, wherein the composition is a lubricant or a lubricating composition.

[0037] In Example 12 of the composition according to the invention, the composition is designed according to its Example 11, wherein the composition is an additive blend. An "additive blend" (also known as an "additive masterbatch" or "additive package") is a blend used to treat industrial and automotive lubricants, which contains a combination of different additives, such as antioxidants, anti-wear additives, dispersants, ashless (metal-free) polymer materials, detergents, anti-foam additives, viscosity index improvers, copper passivators, rust inhibitors, pour point depressants, demulsifiers, and friction improvers. The mixture of alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) according to the invention can thus be formed by a part of such an additive package.

[0038] In Example 13 of the composition according to the invention, the composition is designed according to its Example 12, wherein the additive blend contains additives that are corrosive to lead, preferably additives selected from the group consisting of sulfur-containing antioxidants, sulfur-containing anti-wear additives, sulfur-containing copper passivators, or friction improvers derived from vegetable oils.

[0039] In Example 14 of the composition according to the invention, the composition is designed according to its Example 12 or 13, wherein the total amount of alkylated diphenylamines of structural formulas (I), (II), (III), and (IV), preferably wherein R is a branched residue of the formula -C9H 19 The total amount of alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) is in the range of 0.01 wt% to 30 wt%, preferably in the range of 0.1 wt% to 20 wt%, and even more preferably in the range of 0.5 wt% to 10 wt%, in each case based on the total weight of the additive blend.

[0040] In Example 15 of the composition according to the invention, the composition is designed according to its Example 11, wherein the composition is an engine oil.

[0041] In Example 16 of the composition according to the invention, the composition is designed according to its Example 15, wherein the engine oil contains at least one base oil and a mixture of alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) as defined in Examples 1 to 7, preferably in the form of an additive blend as defined in Examples 12 to 14, preferably wherein R is a branched residue of the formula -C9H 19 The mixture of alkylated diphenylamines of structural formulas (I), (II), (III), and (IV).

[0042] In Example 17 of the composition according to the invention, the composition is designed according to its Example 16, wherein R is a branched C4-C16 The total amount of alkylated diphenylamines of the structural formulas (I), (II), (III) and (IV) of the alkyl group, preferably where R is a branched residue having the formula -C9H 19 The total amount of alkylated diphenylamines of the structural formulas (I), (II), (III) and (IV) having a branched residue is in the range of 0.01% to 5% by weight, preferably in the range of 0.05% to 2.5% by weight, and even more preferably in the range of 0.1% to 1.5% by weight, in each case based on the total weight of the engine oil.

[0043] In Example 18 of the composition according to the invention, the composition is designed according to its Example 11, wherein the composition is a polymer composition comprising a polymer, preferably a thermoplastic polymer, preferably a polyurethane.

[0044] In Example 19 of the composition according to the invention, the composition is designed according to its Example 18, wherein the total amount of alkylated diphenylamines of the structural formulas (I), (II), (III) and (IV), preferably where R is a branched residue having the formula -C9H 19 The total amount of alkylated diphenylamines of the structural formulas (I), (II), (III) and (IV) having a branched residue is in the range of 0.01% to 1.0% by weight, preferably in the range of 0.05% to 0.75% by weight, and even more preferably in the range of 0.1% to 0.5% by weight, in each case based on the total weight of the polymer composition.

[0045] In Example 20 of the composition according to the invention, the composition is designed according to its Example 18 or 19, wherein the thermoplastic polymer is selected from the group consisting of: low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), homopolymers derived from C3 and higher monoene and diene unsaturated hydrocarbon monomers such as polypropylene, polyisobutylene, poly(methylbutene-1), poly(methylpentene-1), poly(butene-1), polyisobutylene, etc.; copolymers derived from two or more monomers such as preferably ethylene-propylene copolymers having at least a majority of propylene, propylene-butene-1 copolymers, propylene-isobutylene copolymers, etc. and their blends, polystyrene; polyhalogenated ethylene; and thermoplastic engineering plastics such as polyamides, polyesters, polyphenylene ethers, polyphenylene sulfides, polyacetals, aliphatic polyketone copolymers or terpolymers, poly(ethersulfone), polycarbonate, liquid crystal polymers, poly(etheretherketone), polyurethanes and poly(arylate). Preferably, the thermoplastic resin protected by the composition according to the invention is polyurethane or polypropylene.

[0046] If the thermoplastic polymer stabilized by the composition according to the invention is a polyurethane, the composition according to the invention can be added to the polyol which is subsequently reacted with an isocyanate to form a polyurethane.

[0047] At least one object according to the invention is also solved by using the composition according to any one of Examples 1 to 10 thereof as an additive in industrial products, preferably as part of an additive blend as defined in Examples 12 to 14, as an additive in engine oil as defined in Examples 15 to 17, or as an additive in a polymer composition as defined in Examples 18 to 20.

[0048] Best mode for carrying out the invention

[0049] Additives in the additive blend according to the present invention

[0050] The additive blend (or additive package) according to the invention is a blend for treating industrial and automotive lubricants, which contains a combination of different additives in addition to the base oil, such as antioxidants, antiwear additives, dispersants, ashless (metal-free) polymer materials, detergents, antifoam additives, viscosity index improvers, copper passivators, rust inhibitors, pour point depressants, demulsifiers, and friction improvers. The mixture of alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) according to the invention, preferably wherein R is a branched residue having the formula -C9H 19 The mixture of alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) can thus be part of such an additive package.

[0051] In addition to the mixture of alkylated diphenylamines of structural formulas (I), (II), (III), and (IV), preferably in addition to the mixture of alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) wherein R is a branched residue having the formula -C9H 19 Suitable antioxidants that can be present in the additive blend are selected from:

[0052] 1) Alkylated monophenols, such as 2,6 - di - tert - butyl - 4 - methylphenol, 2 - butyl - 4,6 - dimethylphenol, 2,6 - di - tert - butyl - 4 - ethylphenol, 2,6 - di - tert - butyl - 4 - n - butylphenol, 2,6 - di - tert - butyl - 4 - isobutylphenol, 2,6 - dicyclopentyl - 4 - methylphenol, 2 - (α - methyl - cyclohexyl) - 4,6 - dimethylphenol, 2,6 - bis(octadecyl) - 4 - methylphenol, 2,4,6 - tricyclohexylphenol, 2,6 - di - tert - butyl - 4 - methoxymethylphenol, linear or branched nonylphenols (e.g., 2,6 - dinonyl - 4 - methylphenol), 2,4 - dimethyl - 6 - (1'-methyl - undecan - 1'-yl)phenol, 2,4 - dimethyl - 6 - (1'-methylheptadecyl - 1'-yl)phenol, 2,4 - dimethyl - 6 - (1'-methyltridecyl - 1'-yl)phenol or mixtures thereof;

[0053] 2) Alkylthiomethylphenols, such as 2,4 - dioctylthiomethyl - 6 - tert - butylphenol, 2,4 - dioctylthiomethyl - 6 - methylphenol, 2,4 - dioctylthiomethyl - 6 - ethylphenol or 2,6 - bis(dodecyl)thiomethyl - 4 - nonylphenol;

[0054] 3) Hydroquinones and alkylated hydroquinones, such as 2,6 - di - tert - butyl - 4 - methoxyphenol, 2,5 - di - tert - butylhydroquinone, 2,5 - di - tert - amylhydroquinone, 2,6 - diphenyl - 4 - octadecyloxyphenol, 2,6 - di - tert - butyl - hydroquinone, 2,5 - di - tert - butyl - 4 - hydroxyanisole, 3,5 - di - tert - butyl - 4 - hydroxyanisole, 3,5 - di - tert - butyl - 4 - hydroxybenzyl stearate or bis(3,5 - di - tert - butyl - 4 - hydroxyphenyl) adipate;

[0055] 4) Tocopherols, such as α - tocopherol, β - tocopherol, γ - tocopherol or δ - tocopherol or mixtures thereof (vitamin E);

[0056] 5) Hydroxylated thiodiphenyl ethers, such as 2,2'-thiobis(6 - tert - butyl - 4 - methylphenol), 2,2'-thiobis(4 - octylphenol), 4,4'-thiobis(6 - tert - butyl - 3 - methylphenol), 4,4'-thiobis(6 - tert - butyl - 2 - methylphenol), 4,4'-thiobis(3,6 - di - sec - amylphenol) or 4,4'-bis(2,6 - dimethyl - 4 - hydroxyphenyl) disulfide;

[0057] 6) Alkylene bisphenols, such as 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis(4-methyl-6-(α-methyl-cyclohexyl)-phenol), 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(6-nonyl-4-methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylenebis(4,6-di-tert-butylphenol), 2,2'-ethylenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis(6-(α-methylbenzyl)-4-nonylphenol), 2,2'-methylenebis(6-(α,α-dimethylbenzyl)-4-nonylphenol), 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-methylenebis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis(butyrate 3,3-bis(3'-tert-butyl-4'-hydroxyphenyl) ester), bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentadiene, terephthalic acid bis(2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tert-butyl-4-methylphenyl) ester, 1,1-bis(3,5-dimethyl-2-hydroxyphenyl)butane, 2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane or 1,1,5,5-tetrakis(5-tert-butyl-4-hydroxy-2-methylphenyl)-pentane;

[0058] 7) O-benzyl, N-benzyl and S-benzyl compounds, such as 3,5,3',5'-tetra-tert-butyl-4,4'-dihydroxy-dibenzyl ether, octadecyl 4-hydroxy-3,5-dimethylbenzylthioacetate, tridecyl 4-hydroxy-3,5-di-tert-butylbenzylthioacetate, tris(3,5-di-tert-butyl)amine, bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) dithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxy-benzyl) sulfide or isooctyl 3,5-di-tert-butyl-4-hydroxy-benzylthioacetate;

[0059] 8) Hydroxybenzylated malonic acid esters, such as di(octadecyl) 2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate, di(octadecyl) 2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate, di(dodecyl) 2-mercaptoethyl 2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate or di(4-(1,1,3,3-tetramethylbutyl)phenyl) 2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate;

[0060] 9) Aromatic hydroxybenzyl compounds, such as 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene or 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol;

[0061] 10) Triazine compounds, such as 2,4-bis(octylthio)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylthio-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylthio-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexahydro-1,3,5-triazine or 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate;

[0062] 11) Benzylphosphonic acid esters, such as dimethyl 2,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, di(octadecyl) 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, di(octadecyl) 5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate or the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid;

[0063] 12) Acylaminophenols, such as 4-hydroxylauroylanilide, 4-hydroxystearanilide or octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate;

[0064] 13) Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, β-(5-tert-butyl)-4-hydroxy-3-methylphenyl)propionic acid, β-(3,5-dicyclohexyl-4-hydroxyphenyl)-propionic acid, 3,5-di-tert-butyl-4-hydroxyphenylacetic acid or β-(5-tert-butyl)-4-hydroxyphenyl))-3-thiabutyric acid with a monohydric or polyhydric alcohol, such as with methanol, ethanol, n-octanol, isooctanol, stearyl alcohol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethyl-hexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo(2.2.2)octane, glycerol, or transesterification products of natural triglycerides based on, for example, coconut oil, rapeseed oil, sunflower oil or colza oil;

[0065] 14) Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, such as N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine or N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine;

[0066] 15) Ascorbic acid (vitamin C);

[0067] 16) Amine antioxidants such as N,N'-diisopropyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N'-bis(1-methylheptyl)-p-phenylenediamine, N,N'-dicyclohexyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-di(naphthalen-2-yl)-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N-(1-methylheptyl)-N'-phenyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenylenediamine, 4-(p-toluenesulfonamido)diphenylamine, N,N'-dimethyl-N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyldiphenylamine, 4-isopropoxydiphenylamine, N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine, N-phenyl-2-naphthylamine, octylated diphenylamine (such as p,p'-di-tert-octyldiphenylamine), 4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylaminophenol, 4-octadecanoylaminophenol, bis(4-methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylaminomethylphenol, 2,4'-diamino-diphenylmethane, 4,4'-diamino-diphenylmethane, N,N,N',N'-tetramethyl-4,4'-diamino-diphenylmethane, 1,2-bis((2-methylphenyl)amino)ethane, 1,2-bis(phenylamino)propane, (o-tolyl)biguanide, bis(4-(1',3'-dimethylbutyl)phenyl)amine, tert-octylated N-phenyl-1-naphthylamine, mixtures of monoalkylated and dialkylated tert-butyl / tert-octyldiphenylamines, mixtures of monoalkylated and dialkylated nonyldiphenylamines, mixtures of monoalkylated and dialkylated dodecyldiphenylamines, mixtures of monoalkylated and dialkylated isopropyl / isobutyldiphenylamines, mixtures of monoalkylated and dialkylated tert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine, mixtures of monoalkylated and dialkylated tert-butyl / tert-octylphenothiazines, mixtures of monoalkylated and dialkylated tert-octylphenothiazines, N-allylphenothiazine, N,N,N',N”-tetraphenyl-1,4-diaminobut-2-ene, N,N-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine, bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate, 2,2,6,6-tetramethylpiperidin-4-one or 2,2,6,6-tetramethylpiperidin-4-ol; and

[0068] 17) esters of aliphatic or aromatic phosphites, thiodipropionic or thiodiacetic acids, or salts of dithiocarbamic or dithiophosphoric acids, 2,2,12,12 - tetramethyl - 5,9 - dihydroxy - 3,7,1 - trithiatridecane or 2,2,15,15 - tetramethyl - 5,12 - dihydroxy - 3,7,10,14 - tetrathiahexadecane.

[0069] Suitable anti - wear additives are selected from:

[0070] 1) Metal salts of dialkyldithiophosphoric acids, where the metal is aluminum, lead, tin, manganese, cobalt, nickel, zinc or copper, but most commonly zinc. The zinc salt (zinc dialkyldithiophosphate) is represented as

[0071]

[0072] where R and R' independently represent C1 - C 20 alkyl, C3 - C 20 alkenyl, C5 - C 12 cycloalkyl, C7 - C 13 aralkyl or C6 - C 10 aryl, for example R and R' are independently C1 - C 12 alkyl; and

[0073] 2) Compounds containing sulfur and / or phosphorus and / or halogen, such as sulfurized olefins and vegetable oils, tricresyl phosphate, trimethylphenyl phosphate, chlorinated paraffins, alkyl and aryl disulfides and trisulfides, amine salts of monoalkyl phosphates and dialkyl phosphates, amine salts of methyl phosphoric acid, diethanolaminomethyltolyltriazole, bis(2 - ethylhexyl)aminomethyltolyltriazole, derivatives of 2,5 - dimercapto - 1,3,4 - thiadiazole, ethyl propionate ((bis(isopropyloxythiophosphoryl)thio)ester), triphenyl thiophosphate (triphenylphosphorothioate), tris(alkylphenyl)phosphorothioates and their mixtures (such as tris(isononylphenyl)phosphorothioate), diphenylmonononylphenyl phosphorothioate, isobutylphenyl diphenyl phosphorothioate, dodecylamine salt of 3 - hydroxy - 1,3 - thiaphospholane - 3 - oxide, tris(2 - isooctyl acetate) trithiophosphate, derivatives of 2 - mercaptobenzothiazole (such as 1 - (N,N - bis(2 - ethylhexyl)aminomethyl)-2 - mercapto - 1H - 1,3 - benzothiazole) or ethoxycarbonyl 5 - octyldithiocarbamate.

[0074] Suitable dispersants are selected from:

[0075] 1) Mannich base, which is a condensation reaction product of a high molecular weight phenol, a propargyl polyamine, and an aldehyde (such as formaldehyde);

[0076] 2) A succinic acid-based dispersant, which is a reaction product of an olefin polymer and a succinic acid acylating agent (acid, anhydride, ester, or halide) further reacted with an organic hydroxy compound and / or an amine; and

[0077] 3) High molecular weight amides and esters, such as reaction products of a hydrocarbyl acylating agent and a polyhydroxy fatty alcohol (such as glycerol, pentaerythritol, or sorbitol).

[0078] Typically, ashless (metal-free) polymer materials are used as dispersants, and such materials usually contain an oil-soluble high molecular weight backbone connected to a polar functional group associated with the particles to be dispersed. Commonly used hydrocarbon backbone materials are olefin polymers and copolymers, namely ethylene, propylene, butene, isobutene, styrene; additional functional groups may or may not be incorporated into the backbone of the polymer. For example, polar materials such as amines, alcohols, amides, or esters are connected to the backbone via a bridging bond.

[0079] Suitable detergents are selected from: calcium, magnesium, barium, sodium, or lithium salts of organic acids, such as sulfonates, alkylphenol salts, sulfurized alkylphenol salts, carboxylates, salicylates, phosphonates, thiophosphonates, and phosphites. The salts can be neutral or can be overbased with, for example, a metal hydroxide or carbonate.

[0080] Suitable anti-foam additives are selected from: silicone oils, polysiloxanes, and polyethylene glycol ethers.

[0081] Suitable viscosity index improvers are selected from: polyisobutene, copolymers of ethylene and propylene, polyacrylates, polymethacrylates, vinyl pyrrolidone / methacrylate copolymers, polyvinyl pyrrolidone, polybutene, olefin copolymers, styrene / acrylic ester copolymers, styrene / isoprene copolymers, styrene / isobutene copolymers, isoprene / butadiene copolymers, and polyethers.

[0082] Suitable copper passivators are selected from:

[0083] 1) Benzotriazole and its derivatives, such as 4-alkylbenzotriazole or 5-alkylbenzotriazole (such as tolyltriazole) and its derivatives, 4,5,6,7-tetrahydrobenzotriazole, 5,5'-methylenebisbenzotriazole; Mannich bases of benzotriazole or tolyltriazole, such as 1-(bis(2-ethylhexyl)aminomethyl)tolyltriazole and 1-(bis(2-ethylhexyl)aminomethyl)-benzotriazole; alkoxyalkylbenzotriazoles, such as 1-(nonyloxymethyl)-benzotriazole, 1-(1-butoxyethyl)-benzotriazole, or 1-(1-cyclohexyloxybutyl)-tolyltriazole;

[0084] 2) Imidazole derivatives, such as 4,4'-methylenebis(2-undecyl-5-methylimidazole), bis((N-methyl)imidazol-2-yl)methanol octyl ether;

[0085] 3) Sulfur-containing heterocyclic compounds, such as 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2,5-dimercaptobenzothiadiazole and its derivatives, or 3,5-bis(di(2-ethylhexyl)aminomethyl)-1,3,4-thiadiazolin-2-one; and

[0086] 4) Amino compounds, such as salicylidene propylenediamine, salicylamino guanidine or its salts.

[0087] Suitable rust inhibitors are selected from:

[0088] 1) Nonionic polyoxyalkylene polyols and their esters, polyoxyalkylene phenols, organic acids, their esters, metal salts, amine salts and acid anhydrides, such as alkyl succinic acids and alkenyl succinic acids and their partial esters with alcohols, diols or hydroxycarboxylic acids, alkyl succinic acids and alkenyl succinic acids, 4-nonylphenoxyacetic acid, alkoxycarboxylic acids and alkoxyethoxycarboxylic acids (such as dodecyloxyacetic acid, dodecyloxy(ethoxy)acetic acid) and partial amides of their amine salts, or N-oleoyl sarcosine, sorbitan monooleate, lead naphthenate and alkenyl succinic anhydrides (such as dodecenyl succinic anhydride), 2-(2-carboxyethyl)-1-dodecyl-3-methylglycerol and its salts, such as sodium salts and triethanolamine salts;

[0089] 2) Nitrogen-containing compounds selected from: i) aliphatic or cycloaliphatic primary, secondary and tertiary amines and amine salts of organic and inorganic acids, such as oil-soluble alkyl carboxyl ammonium salts and 1-(N,N-bis(2-hydroxyethyl)amino)-3-(4-nonylphenoxy)propan-2-ol, or ii) heterocyclic compounds, such as: substituted imidazolines or oxazolines, such as 2-heptadecenyl-1-(2-hydroxyethyl)-imidazoline;

[0090] 3) Phosphorus-containing compounds, such as amine salts of phosphoric acid, partial esters of phosphoric acid or partial esters of phosphonic acid, or zinc dialkyldithiophosphate;

[0091] 4) Sulfur-containing compounds, such as barium dinonylnaphthalene sulfonate, calcium petroleum sulfonate, alkylthio-substituted aliphatic carboxylic acids, esters or salts of aliphatic 2-sulfocarboxylic acids; and

[0092] 5) Glycerol derivatives, such as glycerol monooleate, 1-(alkylphenoxy)-3-(2-hydroxyethyl)glycerol, 1-(alkylphenoxy)-3-(2,3-dihydroxypropyl)glycerol or 2-carboxyalkyl-1,3-dialkylglycerol.

[0093] Suitable pour point depressants are selected from polymethacrylates and alkylated naphthalene derivatives.

[0094] Suitable demulsifiers are selected from polyether polyols and dinonylnaphthalene sulfonates.

[0095] Suitable friction improvers are selected from fatty acids and their derivatives, such as natural esters of fatty acids (such as glycerol monooleate), amides, imides and amines (such as oleylamine), sulfur-containing organomolybdenum dithiocarbamates, sulfur- and phosphorus-containing organomolybdenum dithiophosphates, sulfur- and nitrogen-containing organomolybdenum compounds based on dispersants, molybdenum carboxylate salts, molybdenum-amine complexes, molybdenum-amine / alcohol / amide complexes and molybdenum cluster compounds, and molybdenum disulfide.

[0096] Base oil in the engine oil according to the present invention

[0097] The engine oil according to the invention comprises at least one base oil (i.e. a lubricant having lubricating viscosity) and a mixture of alkylated diphenylamines of formulae (I), (II), (III) and (IV) according to the invention, preferably a mixture of alkylated diphenylamines of formulae (I), (II), (III) and (IV) in which R is a branched residue having the formula -C9H 19 and an additive blend as defined in Examples 12 to 14.

[0098] Suitable base oils are mineral and synthetic base oils selected from Groups I to V. These base oils are widely specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines.

[0099] The base oil can be oils and fats, such as those based on mineral oil or vegetable and animal oils, fats, tallow and waxes or mixtures thereof. Vegetable and animal oils, fats, tallow and waxes are for example palm kernel oil, palm oil, olive oil, rapeseed oil, canola oil, linseed oil, soybean oil, cottonseed oil, sunflower oil, coconut oil, corn oil, castor oil, walnut oil and mixtures thereof, fish oil, and chemically modified (such as epoxidized or sulfoxidized) forms or forms prepared by genetic engineering, such as soybean oil prepared by genetic engineering.

[0100] Examples of synthetic base oils include lubricants based on aliphatic or aromatic carboxylic acid esters, polymeric esters, polyalkylene oxides, phosphate esters, polyalphaolefins, silicones, alkylated benzenes, alkylated naphthalenes or diesters of dibasic acids and monohydric alcohols (such as dioctyl sebacate or dinonyl adipate), triesters of trimethylolpropane with monobasic acids or mixtures of these acids (such as trimethylolpropane trinonanoate, trimethylolpropane trioctanoate or mixtures thereof), tetraesters of pentaerythritol with monobasic acids or mixtures of these acids (such as pentaerythritol tetraoctanoate), or complex esters of monobasic and dibasic acids with polyhydric alcohols (such as a complex ester of trimethylolpropane with octanoic acid and sebacic acid) or mixtures thereof. In addition to mineral oils, particularly suitable are, for example, polyalphaolefins, ester-based lubricants, phosphate esters, glycols, polyglycols and polyalkylene glycols, and mixtures thereof with water.

[0101] When, in addition to the mixtures of alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) according to the invention, preferably in addition to the mixtures of alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) in which R is a branched residue of the formula -C9H 19 other additives are employed, it is desirable (but not essential) to prepare an additive concentrate in the form of an additive blend (or additive package) as described above, which contains a concentrated solution or dispersion of the mixtures of alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) according to the invention with one or more of said other additives, whereby several additives can be added simultaneously to the base oil to form a lubricating oil composition. Dissolution of the additive concentrate in the lubricating oil can be facilitated by solvents and by mixing with gentle heating, but this operation is not essential. The concentrate or additive blend will generally be formulated to contain an appropriate amount of additives to provide the desired concentration in the final formulation when the additive blend is combined with a predetermined amount of base oil. Thus, the mixtures of alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) according to the invention can be added together with other desired additives to a small amount of base oil or other compatible solvent to form an additive blend which contains a total amount of active ingredients (additives in appropriate proportions) generally of from about 2.5 wt% to about 90 wt%, preferably from about 15 wt% to about 75 wt%, and more preferably from about 25 wt% to about 60 wt%, the remainder being base oil. The final formulation can generally use from about 1 wt% to 20 wt% of the additive blend, the remainder being base oil.

[0102] Thermoplastic polymer in the polymer composition according to the present invention

[0103] In addition to the mixtures of alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) according to the invention, preferably in addition to the mixtures of alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) in which R is a branched residue of the formula -C9H 19 the polymer composition according to the invention further comprises a polymer, preferably a thermoplastic polymer.

[0104] Thermoplastic polymers whose oxidative degradation can be stabilized using the mixtures of alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) include: resins derived from ethylene including low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), or other ethylene-derived resins with a density of 0.85 to 1.4 g / cm 3 ; homopolymers derived from C3 and higher monoene and diene unsaturated hydrocarbon monomers, such as polypropylene, polyisobutene, poly(methylbutene-1), poly(methylpentene-1), poly(butene-1), polyisobutylene, etc.; copolymers derived from two or more monomers, such as ethylene-propylene copolymers preferably having at least a majority of propylene, propylene-butene-1 copolymers, propylene-isobutylene copolymers, etc. and their blends, polystyrene; polyhalogenated ethylene; and thermoplastic engineering plastics such as polyamides, polyesters, polyphenylene ethers, polyphenylene sulfides, polyacetals, aliphatic polyketone copolymers or terpolymers, poly(ethersulfone), polycarbonate, liquid crystal polymers, poly(etheretherketone), polyurethanes and poly(arylate). Preferably, the thermoplastic resin protected by the composition according to the invention is polyurethane or polypropylene.

[0105] The invention will now be described in more detail with reference to test methods and non-limiting examples.

[0106] Mode of the Invention

[0107] Test Methods

[0108] Determination of oxidation stability

[0109] The oxidative stability is evaluated by means of a pressure differential scanning calorimetry (PDSC) apparatus.

[0110] PDSC detects the oxidative stability of the oil under thin film oxidation conditions. In the isothermal mode where the PDSC temperature is maintained at a predetermined value, the oxidative stability of the test oil is ranked according to the oxidation induction time (OIT), corresponding to the exotherm caused by the onset of oxidation of the oil. Oils with longer OIT are generally considered more oxidation-resistant. Each mixture is tested twice using the following instrument conditions and the average OIT is determined. The PDSC test temperature is 185 °C.

[0111] The following measurement conditions have been selected:

[0112] Rate of temperature change: 40 °C / min

[0113] Pressure: 500 psi

[0114] O2 flow rate: 100 ml / min

[0115] Sample size: approximately 1.5 mg

[0116] Pan: aluminum, open

[0117] Determination of lead corrosion

[0118] The corrosion of lead was determined according to ASTM D 6594.

[0119] Examples

[0120] To a commercially available mixture of alkylated diphenylamines of structural formulas (I), (II), and (III) in which R represents a branched alkyl group having the formula -C9H 19 corresponding alkylated diphenylamines of structural formula (IV) were added in different amounts, and the resulting product was then designated "TN-DPA" (tetranonyl diphenylamine). Samples in Table 1 were obtained and analyzed:

[0121] [Table 1]

[0122]

[0123] Using the samples described above that contain a mixture of mono-nonyl diphenylamine, di-nonyl diphenylamine, tri-nonyl diphenylamine, and tetra-nonyl diphenylamine, a fully formulated engine oil was prepared. To this end, the samples were added individually in an amount of 1.0 wt% to a fully formulated engine oil that does not contain an antioxidant. The engine oil was formulated with API Group III base oils consisting of a mixture of Yubase4 and Yubase 6 supplied by SK Lubricants Co., Ltd. in Seoul, Korea. The oxidation stability and lead corrosion of the resulting lubricant were determined (by PDSC testing and ASTM D 6594 testing). The results of the PDSC testing are shown in Table 2, and the results of the ASTM D 6594 testing are shown in Table 3:

[0124]

[0125] 1 ) Average of two measurements

[0126] [Table 3]

[0127] 1 ) Average of two measurements

[0128] As can be seen from the results shown in Table 2 and Table 3, adjusting the content of tetraalkylated diphenylamine of structural formula (IV) in the composition of alkylated diphenylamines containing structural formulas (I), (II), (III) and (IV) to an extremely narrow range of 0.2 wt% to 3.5 wt% enables the composition to provide optimal performance in both oxidation stability and resistance to lead corrosion when added to a base oil for forming an engine oil.

Claims

1. A composition selected from the group consisting of an additive, an additive blend, an engine oil, or a polymer, the composition comprising alkylated diphenylamines of structural formulas (I), (II), (III), and (IV): wherein R is a branched alkyl group having the formula -C9H 19 and wherein, based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) in the composition, the total amount of tetra-nonyl diphenylamine of structural formula (IV) is in the range of 0.20 wt% to 3.5 wt%.

2. The composition according to claim 1, wherein, based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) in the composition, the total amount of mono-alkylated diphenylamine of structural formula (I) is in the range of 10 wt% to 35 wt%.

3. The composition according to claim 1 or 2, wherein, based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) in the composition, the total amount of di-alkylated diphenylamine of structural formula (II) is in the range of 60 wt% to 85 wt%.

4. The composition according to claim 1, wherein, based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) in the composition, the total amount of tri-alkylated diphenylamine of structural formula (III) is in the range of 1 wt% to 10 wt%.

5. The composition according to claim 1, wherein the composition further comprises less than 1 wt% of non-alkylated diphenylamine based on the total weight of the alkylated diphenylamines of structural formulas (I), (II), (III), and (IV) in the composition.

6. The composition according to claim 1, wherein at least one of the following conditions (α1) to (α6) is satisfied: (α1) The kinematic viscosity of the composition is in the range of 100 to 1000 cSt; (α2) The Gardner color of the composition is less than 15 Gardner; (α3) The water content of the composition is less than 0.1 wt%; (α4) The nitrogen content of the composition is in the range of 3.2% to 3.8%; (α5) The specific gravity of the composition is in the range of 0.930 to 0.980; (α6) The total base number (TBN) of the composition is in the range of 125 to 160 mg KOH / g.

7. The composition according to claim 6, wherein: (α1) The kinematic viscosity of the composition is measured at a temperature of 40 °C according to ASTM D 445; (α2) The Gardner color of the composition is measured according to ASTM D 1544; (α3) The water content of the composition is measured according to ASTM E 203; (α4) The nitrogen content of the composition is measured according to ASTM D 2896; (α5) The specific gravity of the composition is measured at a temperature of 25 °C according to ASTM D 1298; The total base number (TBN) of the composition is determined according to ASTM D 2896.

8. The composition according to claim 1, wherein the total amount of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) is at least 98% by weight based on the total weight of the composition.

9. The composition according to claim 1, wherein the composition is an additive blend.

10. The composition according to claim 9, wherein the total amount of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) is in the range of 0.01% by weight to 30% by weight based on the total weight of the additive blend.

11. The composition according to claim 1, wherein the composition is an engine oil comprising at least one base oil.

12. The composition according to claim 11, wherein the total amount of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) is in the range of 0.01% by weight to 5% by weight based on the total weight of the engine oil.

13. The composition according to claim 1, wherein the composition is a polymer composition comprising a polymer.

14. The composition according to claim 13, wherein the total amount of the alkylated diphenylamines of structural formulas (I), (II), (III) and (IV) is in the range of 0.01% by weight to 1% by weight based on the total weight of the polymer composition.

15. Use of a composition according to any one of claims 1 to 7 as an additive in an additive blend, an engine oil or a polymer composition.

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