O-alkylated sterically hindered antioxidants

Abstract

This invention relates to a composition comprising a compound of general formula (I) wherein R1 is a straight-chain or branched C1-C24 alkyl group; R2 is a C1-C8 alkyl group; and R3 is a C1-C8 alkyl group. This invention also relates to industrial products, such as additive blends, oils, and polymer compositions comprising this compound of general formula (I), and to the use of this compound of general formula (I) as an additive in industrial products such as additive blends, oils, and polymer compositions.

Description

Technical Field

[0001] This invention relates to a composition comprising an O-alkylation site-resisting oxidant. This invention also relates to a method for preparing an O-alkylation site-resisting oxidant, an industrial product comprising such a composition, and the use of the O-alkylation site-resisting oxidant as an additive in the industrial product. Prior Technology

[0002] As a major type of industrial product, lubricants, such as those used in various machines, are prone to oxidative degradation during storage, transportation, and use, especially when exposed to high temperatures and iron-catalyzed environments, which greatly promotes oxidation. If left uncontrolled, this oxidation leads to the formation of corrosive acidic products, sludge, varnish, resins, and other oil-insoluble products, and can result in the loss of the lubricant's specified physical and tribological properties. Therefore, it is customary to include antioxidants in lubricants to at least partially prevent oxidation in order to extend their service life.

[0003] Lubricating compositions containing various diarylamines or phenolic compounds as antioxidants are widely known in this art. For example, US 5,892,097 discloses the preparation of hindered phenolic compounds and their use as antioxidants. These antioxidants are prepared by reacting an alcohol such as isooctyl alcohol with methyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate to form isooctyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate in a transesterification reaction. However, the antioxidant efficacy of hindered phenolic compounds obtained by such reactions and known from the prior art can be improved.

[0004] Therefore, one objective of the present invention is to overcome the disadvantages of prior art compositions associated with improving the properties of industrial products (such as engine oils), particularly in terms of their oxidative stability.

[0005] Specifically, one object of the present invention is to provide a composition that, when added to a lubricant (such as engine oil) as a separate additive or as a component in a so-called "additive package," improves the properties of the lubricant, particularly in terms of oxidative stability.

[0006] Independent technical solutions contribute to at least partially solving one, and preferably more than one, of the aforementioned objectives. Supplementary technical solutions provide preferred embodiments that facilitate at least partial resolution of at least one of these objectives. Summary of the Invention

[0007] The composition contributing to solving at least one objective according to the present invention comprises i) Compounds of general formula (I) in R1 is a straight-chain or branched C1-C24 alkyl group, preferably methyl or C7-C9 alkyl, more preferably methyl or straight-chain or branched C8 alkyl, and most preferably branched octyl, wherein isooctyl or 2-ethylhexyl or both; R2 is a C1-C8 alkyl group, preferably methyl or ethyl, more preferably methyl; R3 is a C1-C8 alkyl group, preferably a C1-C4 alkyl group, and more preferably a tertiary butyl group.

[0008] Surprisingly, O-alkylated sterically hindered compounds having the general formula (I) have been found to be particularly effective antioxidants compared to their corresponding phenolic derivatives. Not only are pure or substantially pure O-alkylated sterically hindered compounds themselves, preferably pure O-methylated sterically hindered compounds, effective antioxidants, but also, for example, mixtures of commercially available antioxidants based on isooctyl-3,5-di-tertiary butyl-4-hydroxy-hydrogenated cinnamate, to which a certain amount of the corresponding O-alkylated derivative (i.e., isooctyl-3,5-di-tertiary butyl-4-alkoxy-hydrogenated cinnamate, preferably isooctyl-3,5-di-tertiary butyl-4-methoxy-hydrogenated cinnamate) has been added. Implementation

[0009] Compounds of general formula (I) can be prepared by means of a first embodiment of the method according to the present invention, the method comprising the following steps: I) Provide compounds of general formula (I) in R1 is a straight-chain or branched C1-C24 alkyl group, preferably methyl or C7-C9 alkyl, more preferably methyl or straight-chain or branched C8 alkyl, and most preferably branched octyl, wherein isooctyl or 2-ethylhexyl or both; R3 is a C1-C8 alkyl group, preferably a C1-C4 alkyl group, and more preferably a tertiary butyl group; II) React the compound provided in step I) with an alkylating agent containing at least one alkyl group R2, wherein R2 is a C1-C8 alkyl group, preferably methyl or ethyl, more preferably methyl.

[0010] Compounds of general formula (I) can also be prepared by means of a second embodiment of the method according to the present invention, which includes the following method steps: I) Provide compounds of general formula (I) in R3 is a C1-C8 alkyl group, preferably a C1-C4 alkyl group, and more preferably a tertiary butyl group; R4 is a straight-chain or branched-chain C1-C5 alkyl group, preferably methyl; II) React the compound provided in step I) with an alkylating agent containing at least one alkyl group R2, wherein R2 is a C1-C8 alkyl group, preferably methyl or ethyl, more preferably methyl; III) React the compound obtained in step II) with alcohol R1-OH, wherein R1 is a straight-chain or branched C1-C24 alkyl, preferably methyl or C7-C9 alkyl, more preferably methyl or straight-chain or branched C8 alkyl, preferably branched octyl, and most preferably isooctyl or 2-ethylhexyl or both, wherein residue R4 is replaced by residue R1 in the transesterification reaction.

[0011] One of the preferred embodiments of the composition according to the present invention R1 is a C7-C9 alkyl group, more preferably a straight-chain or branched-chain C8 alkyl group, and even more preferably a branched-chain octyl group, wherein isooctyl or 2-ethylhexyl or both are preferred; R2 is a methyl group; R3 is a tertiary butyl.

[0012] Therefore, the preferred antioxidant is octyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate (= octyl 3-(3,5-di-tert-butyl-4-methoxyphenyl)propionate), preferably having one of the following structures:

[0013] Isooctyl-3,5-di-tert-butyl-4-methoxy-hydrocinnamate can be prepared by catalytic O-methylation of isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrocinnamate, for example, using methylating agents such as dimethyl carbonate, methyl iodide, methyl bromide, dimethyl sulfate, diazomethane, methanol, trimethyl strontium salt, or tetramethylammonium salt (such as tetramethylammonium hydroxide or tetramethylammonium chloride). A method for O-methylation of phenols or phenolic derivatives using tetramethylammonium chloride as a methylating agent is disclosed, for example, in Panahi et al., "Efficient and selective microwave-assisted O-methylation of phenolic compounds using tetramethylammonium hydroxide (TMAH)," Green Process Synth (Vol. 8, 2019), pp. 584-589. For example, isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate can be prepared by reacting isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamate with iodomethane in the presence of an alkaline compound (such as KOH), or by first reacting methyl-3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamate with iodomethane in the presence of an alkaline compound (such as KOH) to obtain methyl 3-(3,5-di-tert-butyl-4-methoxyphenyl)propionate, and then reacting methyl 3-(3,5-di-tert-butyl-4-methoxyphenyl)propionate with isooctyl alcohol to obtain isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate in a transesterification reaction.

[0014] According to another preferred embodiment of the composition of the present invention, in each case, the composition comprises at least 0.1% by weight, or at least 1% by weight, or 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 50% by weight, or at least 60% by weight, or at least 70% by weight, or at least 80% by weight, or at least 90% by weight, or at least 95% by weight, or at least 99% by weight of a compound of general formula (I), preferably isooctyl-3,5-di-tertiary butyl-4-methoxy-hydrogenated cinnamic acid ester. According to a specific embodiment of the composition of the present invention, in each case, the content of the compound of general formula (I) in the composition (preferably the content of isooctyl-3,5-di-tertiary butyl-4-methoxy-hydrogenated cinnamic acid ester) is in the range of 0.1% to 99% by weight, more preferably in the range of 1% to 95% by weight, and even more preferably in the range of 5% to 90% by weight, based on the total weight of the composition.

[0015] In another specific embodiment of the composition according to the invention, this composition was obtained by supplementing the composition containing isooctyl-3,5-di-tert-butyl-4-alkoxymethoxyhydrocinnamate with a corresponding O-alkylated derivative (i.e., with a certain amount of isooctyl-3,5-di-tert-butyl-4-methoxy-hydrocinnamate, preferably isooctyl-3,5-di-tert-butyl-4-methoxy-hydrocinnamate) to the composition containing isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrocinnamate.

[0016] According to another specific embodiment of the composition of the present invention, the composition therefore further comprises ii) Octyl-3,5-di-tertiary butyl-4-hydroxy-hydrogenated cinnamate, having one of the general structures (II), preferably isooctyl-3,5-di-tertiary butyl-4-hydroxy-hydrogenated cinnamate:

[0017] In this particular embodiment of the composition according to the invention, it is further preferred that the composition comprises i) at least 0.01% by weight, preferably at least 0.1% by weight and more preferably at least 1% by weight of octyl-3,5-di-tert-butyl-4-methoxyhydrocinnamate, preferably isooctyl-3,5-di-tert-butyl-4-methoxyhydrocinnamate, wherein also preferably, the amount of octyl-3,5-di-tert-butyl-4-methoxyhydrocinnamate is less than 35% by weight, preferably less than 25% by weight and more preferably less than 15% by weight; ii) At least 25% by weight, preferably at least 45% by weight and more preferably at least 65% by weight of octyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate, preferably isooctyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate, wherein, more preferably, the amount of octyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate is less than 99.99% by weight, preferably less than 99.9% by weight and more preferably less than 99% by weight; In all cases, the total weight of components i) and ii) in the composition shall be used.

[0018] In this particular embodiment of the composition according to the invention, it is further preferred that the composition comprises iii) Less than 5% by weight, preferably less than 2.5% by weight, and even more preferably less than 1% by weight, of compounds belonging to the following group of composition. - Dioctyl-α-(3,5-di-tertiary-butyl-4-hydroxybenzyl)glutarate, preferably having dioctyl-α-(3,5-di-tertiary-butyl-4-hydroxybenzyl)glutarate of formula (III), wherein Rx and Ry are independently selected from the group consisting of isooctyl and 2-ethylhexyl, most preferably diisooctyl-α-(3,5-di-tertiary-butyl-4-hydroxybenzyl)glutarate. - Di- and tertiary butylphenol, - Methyl-3,5-bis-tert-butyl-4-hydroxy-hydrogenated cinnamate, - Dimethyl-α-(3,5-di-tert-butyl-4-hydroxybenzyl)glutarate and - Alcohol, preferably octanol, even better isooctyl alcohol. In all cases, the total weight of components i), ii) and iii) in the composition shall be used.

[0019] In this particular embodiment of the composition according to the invention, it is further preferred that the composition comprises octyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate and dioctyl-α-(3,5-di-tert-butyl-4-hydroxybenzyl)glutarate, preferably isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate and diisooctyl-α-(3,5-di-tert-butyl-4-hydroxybenzyl)glutarate, in a weight ratio of at least 2:1, preferably at least 3:1, more preferably at least 4:1, even more preferably at least 6:1, even more preferably at least 8:1, even more preferably at least 10:1, even more preferably at least 15:1 and most preferably at least 20:1.

[0020] In this particular embodiment of the composition according to the invention, it is also preferred that, in each case, the composition comprises, by total weight of the composition, 1 to 50% by weight, preferably 1.5 to 45% by weight, more preferably 2 to 40% by weight, more preferably 2.5 to 35% by weight, more preferably 3 to 30% by weight, more preferably 3.5 to 25% by weight, and even more preferably 4 to 20% by weight of a compound of general formula (I), preferably isooctyl-3,5-di-tertiary butyl-4-methoxy-hydrogenated cinnamate.

[0021] In this particular embodiment of the composition according to the invention, it is also preferred that at least one of the following conditions (α1) to (α5) is satisfied, and preferably all of the following conditions (α1) to (α5) are satisfied: (α1) The composition has a kinematic viscosity in the range of 60 to 300 cSt, more preferably in the range of 80 to 250 cSt, and even more preferably in the range of 100 to 200 cSt (as determined according to ASTM D 445 at a temperature of 40°C); (α2) The composition has a Gardner color of less than 10 Gardners, preferably less than 5 Gardners, and more preferably less than 3 Gardners (as determined according to ASTM D 1544); (α3) The composition has a water content of less than 0.5% by weight, preferably less than 0.3% by weight, and more preferably less than 0.1% by weight (as determined according to ASTM E 203); (α4) The composition has a specific gravity in the range of 0.900 to 1.020, preferably in the range of 0.925 to 1.010, and even more preferably in the range of 0.940 to 1.000 (measured according to ASTM D 1298 at 25°C); (α5) The composition has a total acid value (as determined by ASTM D664) of less than 5.0 mg KOH / g, preferably less than 2.5 mg KOH / g, and more preferably less than 1.0 mg KOH / g.

[0022] In a first variant of the composition according to the invention, in each case, the total amount of component i) (if the composition does not contain component ii) or the total amount of components i) and ii) (if the composition contains component ii) is at least 95% by weight, preferably at least 97% by weight, and more preferably at least 99% by weight, based on the total weight of the composition. The composition is thus present as an individual additive that can be used to improve the oxidative stability of industrial products (such as lubricants, lubricating compositions, or polymer compositions).

[0023] In a second variation of the composition according to the invention, the composition is a lubricant or a lubricating composition. In this second variation of the composition according to the invention, it is particularly preferred that the composition is an additive blend. An "additive blend" (also called an "additive package") is a blend used to treat industrial and automotive lubricants, comprising a combination of various additives such as antioxidants, anti-wear additives, dispersants, ashless (metal-free) polymers, detergents, defoamers, viscosity index improvers, copper passivators, rust inhibitors, pour point depressants, demulsifiers, and friction modifiers. Compositions comprising compounds of general formula (I) according to the invention, preferably compositions comprising isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamic acid ester, can therefore be present in such additive package form.

[0024] In this second variant of the composition according to the invention, it is particularly preferred that, in each case, the total amount of component i) (if the composition does not contain component ii) or the total amount of components i) and ii) (if the composition contains component ii) is in the range of 0.01 to 95% by weight, more preferably in the range of 0.1 to 60% by weight, and even more preferably in the range of 0.5 to 30% by weight, based on the total weight of the additive blend.

[0025] According to a third variation of the composition of the present invention, the composition is a motor oil comprising at least one base oil. In the case of the third variation of the composition of the present invention, particularly preferably, in each case, the total amount of component i) (if the composition does not contain component ii) or the total amount of components i) and ii) (if the composition contains component ii) is in the range of 0.01 to 10% by weight, more preferably in the range of 0.05 to 5% by weight, and even more preferably in the range of 0.1 to 2% by weight, based on the total weight of the motor oil.

[0026] According to a fourth variation of the composition of the present invention, the composition is a polymer composition comprising a polymer (preferably a thermoplastic polymer, a rigid plastic polymer), an elastomer, a polyol, a rubber (such as butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene propylene rubber (EPR), acrylonitrile butadiene rubber (NBR)) or a mixture thereof, or a mixture comprising at least two of such polymers. In this fourth variation of the composition of the present invention, it is particularly preferred that, in each case, the total amount of component i) (if the composition does not contain component ii) or the total amount of components i) and ii) (if the composition contains component ii) is in the range of 0.01 to 10% by weight, more preferably in the range of 0.05 to 2.0% by weight, and even more preferably in the range of 0.1 to 1.0% by weight, based on the total weight of the polymer composition.

[0027] In this fourth variant of the composition according to the invention, it is particularly preferred that the thermoplastic polymer system 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 mono- and diene unsaturated hydrocarbon monomers of C3 and above, such as polypropylene, polyisobutylene, polymethylbutene-1, polymethylpentene-1, polybutene-1, and the like; 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, and the like, and blends thereof, polystyrene; polyvinylhalide; and engineering thermoplastics, such as polyamide, polyester, polyphenylene ether, polyphenylene sulfide, polyacetal, aliphatic polyketide copolymers or terpolymers, poly(ether ether), polycarbonate, liquid crystal polymers, poly(ether ether ketone), polyurethane, and poly(aryl ester). Preferably, the thermoplastic resin protected by the composition according to the present invention is a polyurethane or polypropylene.

[0028] If the polymer to be stabilized by the composition according to the invention is a polyurethane, for example, for the production of flexible or rigid foams, the composition according to the invention can be added to a polyol that subsequently reacts with an isocyanate to form a polyurethane.

[0029] The use of compounds of the following general formula (I) also contributes to solving at least one objective according to the present invention. in R1 is a straight-chain or branched C1-C24 alkyl group, preferably methyl or C7-C9 alkyl, more preferably methyl or straight-chain or branched C8 alkyl, and most preferably branched octyl, wherein isooctyl or 2-ethylhexyl or both; R2 is a C1-C8 alkyl group, preferably methyl or ethyl, more preferably methyl; R3 is a C1-C8 alkyl group, preferably a C1-C4 alkyl group, and more preferably a tertiary butyl group; The compound is used as an additive in lubricating compositions, preferably in engine oils, or in polymer compositions or both. The compound of general formula (I) is preferably isooctyl-3,5-di-tert-butyl-4-methoxy-hydrocinnamate.

[0030] [] [Additives in the additive blend according to the present invention] [] The additive blends (or additive packages) according to the present invention are blends for treating industrial and automotive lubricants, comprising, in addition to base oils, combinations of various additives such as antioxidants, anti-wear additives, dispersants, ashless (metal-free) polymers, detergents, defoamers, viscosity index improvers, copper passivators, rust inhibitors, pour point depressants, demulsifiers, and friction modifiers. Compositions comprising compounds of general formula (I), preferably compositions comprising isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamic acid ester, may therefore be part of such additive packages.

[0031] In addition to compositions containing compounds of general formula (I), it is preferable that, in addition to compositions containing isooctyl-3,5-di-tri-butyl-4-methoxy-hydrogenated cinnamic acid ester, a suitable antioxidant may be present, selected from: 1) Alkylated monophenols, such as 2,6-di-tert-butyl-4-methylphenol, 2-butyl-4,6-di-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-di-cyclopentyl-4-methylphenol, 2-(α-methyl-cyclohexyl)-4,6-dimethylphenol, 2 6-Di-octadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tributyl-4-methoxymethylphenol, straight-chain or side-chain branched nonylphenol, such as 2,6-dinonyl-4-methylphenol, 2,4-dimethyl-6-(1'-methyl-undecane-1'-yl)phenol, 2,4-dimethyl-6-(1'-methylheptadecane-1'-yl)phenol, 2,4-dimethyl-6-(1'-methyl-tetrazane-1'-yl)phenol or mixtures thereof; 2) Alkylthiomethylphenols, such as 2,4-di-octylthiomethyl-6-tert-butylphenol, 2,4-di-octylthiomethyl-6-methylphenol, 2,4-di-octylthiomethyl-6-ethylphenol, or 2,6-di-dodecylthiomethyl-4-nonylphenol; 3) Hydroquinone and alkylated hydroquinones, such as 2,6-di-tert-butyl-4-methoxy-phenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-pentylhydroquinone, 2,6-diphenyl-4-octadecoxyphenol, 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-hydroxyphenyl stearate or bis(3,5-di-tert-butyl-4-hydroxyphenyl) adipate; 4) Tocopherols, such as α-, β-, γ-, or δ-tocopherol or mixtures thereof (vitamin E); 5) Hydroxylated thiodiphenyl ethers, such as 2,2'-thiobis(6-tertiary butyl-4-methylphenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tertiary butyl-3-methylphenol), 4,4'-thiobis(6-tertiary butyl-2-methylphenol), 4,4'-thiobis(3,6-di-secondary pentylphenol), or 4,4'-bis(2,6-dimethyl-4-hydroxyphenyl) disulfide; 6) Alkyl 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'-ethyl -Bis(4,6-di-tertiary butylphenol), 2,2'-epenylethylbis(6-tertiary 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-tertiary butylphenol), 4,4'-methylenebis(6-tertiary butyl-2-methylphenol), 1,1-bis(5-tertiary butyl-4-hydroxy 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-dodecyl mercaptobutane, ethylene glycol bis(3,3-bis(3'-tert-butyl-4'-hydroxyphenyl)butyrate, bis(3-tert-butyl-4-hydroxy-5-methylphenyl)dicyclopentane Diene, bis(2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tert-butyl-4-methylphenyl) terephthalate, 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-tetra(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane; 7) O-, N-, and S-benzyl compounds, such as 3,5,3',5'-tetra-tertiary butyl-4,4'-dihydroxy-dibenzyl ether, 4-hydroxy-3,5-dimethylbenzyl mercaptoacetate octadecyl ester, 4-hydroxy-3,5-di-tertiary butylbenzyl mercaptoacetate tridecyl ester, tris(3,5-di-tertiary butyl)amine, bis(4-tertiary butyl-3-hydroxy-2,6-dimethylbenzyl) dithioterephthalate, bis(3,5-di-tertiary butyl-4-hydroxy-benzyl) sulfide, or 3,5-di-tertiary butyl-4-hydroxy-benzyl mercaptoacetate isooctyl ester; 8) Hydroxybenzylated malonates, such as octacodecyl 2,2-bis(3,5-di-tertiary butyl-2-hydroxybenzyl)malonate, octacodecyl 2-(3-tertiary butyl-4-hydroxy-5-methylbenzyl)malonate, mercaptoethyl-2,2-bis(3,5-di-tertiary butyl-4-hydroxybenzyl)malonate d-dodecyl or bis(4-(1,1,3,3-tetramethylbutyl)phenyl)-2,2-bis(3,5-di-tertiary butyl-4-hydroxybenzyl)malonate; 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; 10) Triple compounds, such as 2,4-bisoctylmercapto-6-(3,5-di-tert-butyl-4-hydroxyaniline)-1,3,5-triple, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyaniline)-1,3,5-triple, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triple, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triple, 1, 3,5-tris(3,5-di-tertiary butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris(4-tertiary butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 2,4,6-tris(3,5-di-tertiary butyl-4-hydroxyphenylethyl)-1,3,5-tris(tris(3,5-di-tertiary butyl-4-hydroxyphenylpropionyl)hexahydro-1,3,5-tris(tris(3,5-di-tertiary butyl-4-hydroxyphenylpropionyl)hexahydro-1,3,5-tris(tris(3,5-dicyclohexyl-4-hydroxybenzyl) isocyanurate; 11) Benzylphosphonates, such as dimethyl 2,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, octadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, octadecyl 5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate, or calcium salts of monoethyl esters of 3,5-di-tert-butyl-4-hydroxybenzylphosphonate; 12) Acetaminophenols, such as 4-hydroxylauroyl aniline, 4-hydroxystearyl aniline, or octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)aminocarbamate; 13) The following esters: 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-thiobutyric acid, and monohydric or polyhydric alcohols, such as 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, neopentyl tetroxide, tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)oxadiazine, 3-thiadecyl alcohol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo(2.2.2)octane, glycerol, or transesterification products based on natural triglycerides, such as coconut oil, rapeseed oil, sunflower oil, or canola oil; 14) Acetamides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, such as N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionic acid)hexanediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionic acid)trimethylenediamine, or N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionic acid)hydrazine; 15) Ascorbic acid (vitamin C); 16) Amine-type antioxidants, such as N,N'-diisopropyl-p-phenylenediamine, N,N'-di-di-di-butyl-p-phenylenediamine, N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3-methyl-pentyl)-p-phenylenediamine, N,N'-bis(1-methyl-heptyl)-p-phenylenediamine, N,N'-dicyclohexyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-di-(naphthyl-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-toluenesulfonylamino)diphenylamine, N,N'-dimethyl-N,N'-di-secondary butyl-p-phenylenediamine, diphenylamine, N-allyl diphenylamine, 4-isopropoxy-diphenylamine, N-phenyl-1-naphthylamine, N-(4-tertiary octylphenyl)-1-naphthylamine, N-phenyl-2-naphthylamine, octylated diphenylamine, such as p,p'-di-tertiary octyl diphenylamine, 4-n-butylaminophenol, 4-butyrylamine phenol, 4-nonyrylamine phenol, 4-dodecylamine phenol, 4-octadecylamine phenol, di-(4-methoxyphenyl)-amine, 2,6-di-tertiary butyl-4-dimethylamino-methylphenol, 2,4 '-Diamino-diphenylmethane, 4,4'-diamino-diphenylmethane, N,N,N',N'-tetramethyl-4,4'-diamino-diphenylmethane, 1,2-di-((2-methyl-phenyl)-amino)ethane, 1,2-di-(aniline)propane, (o-tolyl)biguanidine, di(4-(1',3'-dimethyl-butyl)-phenyl)-amine, tertiary octylated N-phenyl-1-naphthylamine, mixtures of monoalkylated and dialkylated tertiary butyl / tertiary octyl diphenylamine, mixtures of monoalkylated and dialkylated nonyl diphenylamine, mixtures of monoalkylated and dialkylated dodecyl diphenylamine, mixtures of monoalkylated and dialkylated isopropyl / isohexyl diphenylamine Mixtures of monoalkylated and dialkylated tert-butyldiphenylamine, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazoline, phenanthrene, mixtures of monoalkylated and dialkylated tert-butyl / tert-octylphenanthrene, mixtures of monoalkylated and dialkylated tert-octylphenanthrene, N-allylphenanthrene, 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 17) Aliphatic or aromatic phosphites, thiodipropionates or thiodiacetic acids, or dithiocarbamates or dithiophosphates, 2,2,12,12-tetramethyl-5,9-dihydroxy-3,7,1-trithiotridecane or 2,2,15,15-tetramethyl-5,12-dihydroxy-3,7,10,14-tetrathiohexadecane.

[0032] Suitable anti-wear additives are selected from: 1) Dialkyl dithiophosphate metal salts, wherein the metal is aluminum, lead, tin, manganese, cobalt, nickel, zinc, or copper, but most commonly zinc. Zinc salts (zinc dialkyl dithiophosphate) are represented as... Wherein R and R' independently represent C1-C20 alkyl, C3-C20 alkenyl, C5-C12 cycloalkyl, C7-C13 aralkyl, or C6-C10 aryl, for example, R and R' independently represent C1-C12 alkyl; and 2) Sulfur- and / or phosphorus- and / or halogen-containing compounds, such as sulfurized alkenes and vegetable oils, tritolyl phosphate, tricresyl phosphate, chlorinated alkanes, disulfides and trisulfides of alkyl and aryl groups, monoalkylamine salts and dialkylamine salts of phosphates, methylphosphonic acid amine salts, diethanolamine methyltolutriazole, di(2-ethylhexyl)aminomethyltolutriazole, derivatives of 2,5-dimercapto-1,3,4-thiadiazole, ethyl ((diisopropoxythiophosphoryl)thio)propionate, triphenyl thiophosphate. Phosphorothioate, tri(alkylphenyl) thiophosphate and mixtures thereof (e.g., tri(isononylphenyl) thiophosphate), diphenylmononylphenyl thiophosphate, isobutylphenyl diphenyl thiophosphate, 3-hydroxy-1,3-thiaphosphetan-3-dodecylamine salt, 5,5,5-tris(2-acetic acid isooctyl) trithiophosphate, 2-mercaptobenzothiazole derivatives such as 1-(N,N-bis(2-ethylhexyl)aminomethyl)-2-mercapto-1H-1,3-benzothiazole or 5-octyl dithioaminocarbamate ethoxycarbonyl ester.

[0033] Suitable dispersant systems are selected from: 1) Mannich bases as products of the condensation reaction of high molecular weight phenols, propyne polyamines, and aldehydes (such as formaldehyde); 2) The succinic acid-based dispersant of the reaction product of olefin polymers and succinic acid refining agents (acids, anhydrides, esters, or halides) is further reacted with organic hydroxyl compounds and / or amines; and 3) Reaction products of high molecular weight amides and esters, such as hydrocarbon amides and polyaliphatic alcohols (such as glycerol, neopentyl tertrol or sorbitol).

[0034] Ashless (metal-free) polymers containing an oil-soluble, high-molecular-weight backbone linked to polar functional groups are commonly used as dispersants. These polar functional groups associate with the particles to be dispersed. Commonly used hydrocarbon backbone materials are olefin polymers and copolymers, namely ethylene, propylene, butene, isobutene, and styrene; other functional groups may or may not be incorporated into the polymer backbone. Polar materials such as amines, alcohols, amides, or esters are connected to the backbone via bridging.

[0035] Suitable cleaning agents are selected from calcium, magnesium, barium, sodium, or lithium salts of organic acids, such as sulfonates, alkylphenols, sulfurized alkylphenols, carboxylates, salicylates, phosphonates, thiophosphonates, and phosphonites. These salts may be neutral or may be excessively alkalized by, for example, metal hydroxides or carbonates.

[0036] Suitable defoamer additives are selected from: polysiloxane, polysiloxane and polyethylene glycol ether.

[0037] Suitable viscosity index improvers are selected from: polyisobutylene, copolymers of ethylene and propylene, polyacrylates, polymethacrylates, vinylpyrrolidone / methacrylate copolymers, polyvinylpyrrolidone, polybutene, olefin copolymers, styrene / acrylate copolymers, styrene / isoprene copolymers, styrene / isobutadiene copolymers, isoprene / butadiene copolymers, and polyethers.

[0038] Suitable copper passivating agents are selected from: 1) Benzotriazoles and their derivatives, such as 4- or 5-alkylbenzotriazoles (e.g., toluenetriazole) and their derivatives, 4,5,6,7-tetrahydrobenzotriazole, 5,5'-methylenebisbenzotriazole; Mannich bases of benzotriazoles or toluenetriazoles, such as 1-(di(2-ethylhexyl)aminomethyl)toluenetriazole and 1-(di-(2-ethylhexyl)aminomethyl)-benzotriazole; alkoxyalkylbenzotriazoles, such as 1-(nonoxymethyl)-benzotriazole, 1-(1-butoxyethyl)-benzotriazole or 1-(1-cyclohexyloxybutyl)-toluenetriazole; 2) Imidazole derivatives, such as 4,4'-methylenebis(2-undecyl-5-methylimidazolium) and bis((N-methyl)imidazol-2-yl)methanol octyl ether; 3) Sulfur-containing heterocyclic compounds, such as 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2,5-dimercaptobenzothiazole and their derivatives, or 3,5-bis(di(2-ethylhexyl)aminomethyl)-1,3,4-thiadiazole-2-one; and 4) Amine compounds, such as salinomylacetylpropenediamine, salinomylacetylguanidine or their salts.

[0039] Suitable rust inhibitors are selected from: 1) Nonionic polyoxyalkylene polyols and their esters, polyoxyalkylene phenols, organic acids, their esters, metal salts, amine salts and acid anhydrides, such as alkyl succinic acid and alkenyl succinic acid and their metaesters with alcohols, glycols or hydroxycarboxylic acids, alkyl succinic acid and alkenyl succinic acid, 4-nonylphenoxyacetic acid, alkoxycarboxylic acids and alkoxyethoxycarboxylic acids metaamides, such as dodecyloxyacetic acid, dodecyloxy(ethoxy)acetic acid and their amine salts, or N-oleosarcosinate, sorbitan monooleate, lead naphthate and alkenyl succinic anhydride, such as dodecenyl succinic anhydride, 2-(2-carboxyethyl)-1-dodecyl-3-methylglycerol and their salts, such as sodium and triethanolamine salts; 2) Selected from the following nitrogen-containing compounds: i) primary, secondary or tertiary aliphatic or cyclic aliphatic amines, and amine salts of organic and inorganic acids, such as oil-soluble alkylammonium carboxylic acids, and 1-(N,N-bis(2-hydroxyethyl)amino)-3-(4-nonylphenoxy)prop-2-ol, or ii) heterocyclic compounds, such as substituted imidazolines or acezolines, such as 2-heptadecenyl-1-(2-hydroxyethyl)-imidazoline; 3) Phosphorus-containing compounds, such as ammonium phosphates, metaphosphates, or phosphonates, or zinc dialkyl dithiophosphates; 4) Sulfur-containing compounds, such as barium dinonylnaphthalenesulfonate, calcium petroleum sulfonate, alkylthio-substituted aliphatic carboxylic acids, esters of aliphatic 2-sulfocarboxylic acids, or their salts; and 5) Glyceryl derivatives, such as glyceryl monooleate, 1-(alkylphenoxy)-3-(2-hydroxyethyl)glycerol, 1-(alkylphenoxy)-3-(2,3-dihydroxypropyl)glycerol or 2-carboxyl-1,3-dialkylglycerol.

[0040] Suitable flow point depressants are selected from polymethacrylates and alkyl naphthalene derivatives.

[0041] Suitable demulsifiers are selected from polyether polyols and dinonylnaphthalene sulfonate.

[0042] Suitable friction modifiers are selected from fatty acids and their derivatives, such as natural esters of fatty acids, such as glyceryl monooleate, amides, amides and amines, such as oleylamine, sulfur-containing dithiocarbamate organic molybdenum, sulfur-containing phosphorus dithiophosphate organic molybdenum, dispersant-based sulfur-nitrogen organic molybdenum compounds, carboxylic acid molybdenum salts, molybdenum-amine complexes, molybdenum amine / alcohol / amide complexes and molybdenum clusters, Teflon® and molybdenum disulfide.

[0043] [Base oil in the lubricant according to the present invention] [] According to the lubricant of the present invention, the preferred engine oil comprises at least one base oil (i.e., a lubricant having lubricating viscosity) and a composition comprising a compound of general formula (I) according to the present invention, preferably a composition comprising isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamic acid ester.

[0044] Suitable base oils are selected from Group I through Group V mineral oils and synthetic base oils. These base oils are widely specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines.

[0045] Base oils can be oils and greases, such as those based on mineral oils or vegetable oils and animal oils, fats, animal fats and waxes, or mixtures thereof. Vegetable oils and animal oils, fats, animal fats and waxes include, for example, palm kernel oil, palm oil, olive oil, rapeseed oil, flaxseed oil, soybean oil, cottonseed oil, sunflower oil, coconut oil, corn oil, castor oil, walnut oil, and mixtures thereof, fish oil, and chemically modified forms, such as epoxidized or sulfidated forms, or forms prepared by genetic engineering, such as genetically engineered soybean oil.

[0046] Examples of synthetic base oils include lubricants based on: aliphatic or aromatic carboxylic acid esters, polymeric esters, polyepoxides, phosphate esters, poly-α-olefins, polysiloxanes, alkylbenzenes, alkylnaphthalenes, or diesters of diacids and monohydric alcohols, such as dioctyl sebacate or dinonyl adipate; triesters of trimethylolpropane and monobasic acids or mixtures thereof, such as tripelargonate, trimethylolpropane trioctyl ester, or mixtures thereof; tetraesters of neopentyl terephthalol and monobasic acids or mixtures thereof, such as neopentyl terephthalol tetraoctanoate; or complex esters of monobasic acids and diacids and polyols, such as complex esters of trimethylolpropane with octanoic acid and sebacate, or mixtures thereof. Particularly suitable, besides mineral oils, are, for example, poly-α-olefins, ester-based lubricants, phosphate esters, ethylene glycol, polyethylene glycol, and polyvinyl alcohols and their mixtures with water.

[0047] When other additives are used in addition to compositions containing compounds of general formula (I) according to the invention, preferably in addition to compositions containing isooctyl-3,5-di-tertiary butyl-4-methoxy-hydrogenated cinnamate, although not necessary, it may be desirable to prepare additive concentrates in the form of the above-mentioned additive blends (or additive packages), such additive concentrates comprising a concentrated solution or dispersant of a composition containing compounds of general formula (I) according to the invention, preferably containing a concentrated solution or dispersant comprising isooctyl-3,5-di-tertiary butyl-4-methoxy-hydrogenated cinnamate and one or more of such other additives, thereby allowing the simultaneous addition of several additives to a base oil to form a lubricating oil composition. Dissolving the additive concentrate in the lubricating oil can be promoted by solvent and mixing accompanied by mild heating, but this is not essential. When the additive blend is combined with a predetermined amount of base oil, the concentrate or additive blend will generally be formulated to contain an appropriate amount of additive to provide the desired concentration in the final formulation. Therefore, compositions comprising compounds of general formula (I) according to the present invention can be added together with other desired additives to a minimum amount of base oil or other compatible solvent to form an additive blend containing active ingredients, the total amount of which is typically from about 2.5 to about 90% by weight, preferably from about 15 to about 75% by weight, and more preferably from about 25% to about 60% by weight of additives, in appropriate proportion to the remainder of the base oil. The final formulation may typically consist of about 1 to 20% by weight of the additive blend, with the remainder being the base oil.

[0048] [The polymer in the polymer composition according to the present invention] [] In addition to compositions comprising compounds of general formula (I) according to the invention, preferably in addition to compositions comprising isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamic acid ester, polymer compositions according to the invention also comprise polymers (preferably thermoplastic polymers, rigid plastic polymers), elastomers, polyols, rubbers (such as butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene propylene rubber (EPR), acrylonitrile butadiene rubber (NBR)) or mixtures thereof, or mixtures comprising at least two of such polymers.

[0049] Thermoplastic polymers stabilized against oxidative decomposition, including ethylene-derived resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), or those with a density of 0.85 to 1.4 gm / cm³, can be used in combination comprising compounds of general formula (I) according to the present invention. 3. Other ethylene-derived resins; homopolymers derived from mono- and diene unsaturated hydrocarbon monomers of C3 and higher carbon, such as polypropylene, polyisobutylene, polymethylbutene-1, polymethylpentene-1, polybutene-1, and the like; 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, and the like, and blends thereof, polystyrene; polyhalogenated ethylene; and engineering thermoplastics, such as polyamide, polyester, polyphenylene ether, polyphenylene sulfide, polyacetal, aliphatic polyketide copolymers or terpolymers, poly(ether ether), polycarbonate, liquid crystal polymers, poly(ether ether ketone), polyurethane, and poly(aryl ester). Preferably, the thermoplastic resin protected by the composition according to the invention is a polyurethane or polypropylene.

[0050] The invention will now be described in more detail with reference to test methods and non-limiting examples.

[0051] Test methods [Determination of Oxidative Stability] [] Oxidative stability was assessed using a pressure differential scanning calorimetry (PDSC) device.

[0052] PDSC was used to examine the oxidative stability of oils under thin-film oxidation conditions. In an isothermal mode where the PDSC temperature was maintained at a predetermined value, the oxidative stability of the oils was graded according to the oxidation induction time (OIT), corresponding to the exothermic release caused by the initiation of oxidation. Oils exhibiting longer OIT are generally considered to have stronger oxidation resistance. Each blend was tested twice using the following instrument conditions, and the average OIT was measured. The PDSC test temperature was 180°C.

[0053] The following measurement conditions have been selected: Temperature gradient: 40℃ / min Pressure: 500 psi O2 flow rate: 100 ml / min Sample size: approximately 1.5 mg Plate: Aluminum, Open

[0054] Example [Synthesis Example] [1] [] 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropionic acid-C7-9-branched alkyl ester, KOH, and iodomethane were stirred in acetone at room temperature for 18 hours. The reaction mixture was concentrated under vacuum, and the residue was partitioned between ethyl acetate and H₂O. The aqueous phases were extracted three times with ethyl acetate, combined, dried (MgSO₄), and concentrated under vacuum. The product was obtained by distillation of the crude product.

[0055] [Synthesis Example] [2] [] Methyl 3-(3,5-di-tertiary butyl-4-hydroxyphenyl)propionate, KOH, and iodomethane were stirred in acetone at room temperature for 18 hours. The reaction mixture was concentrated under vacuum, and the residue was partitioned between ethyl acetate and H₂O. The aqueous phases were extracted three times with ethyl acetate, combined, dried (MgSO₄), and the organic matter was concentrated under vacuum to obtain a composition containing methyl 3-(3,5-di-tertiary butyl-4-methoxyphenyl)propionate.

[0056] Methyl 3-(3,5-di-tert-butyl-4-methoxyphenyl)propionate, isooctyl alcohol, and aluminum were stirred at 190°C for 18 hours. The reaction mixture was then concentrated under vacuum. The product was obtained by distillation of the crude product.

[0057] [Example] [1] [:] [] The isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate prepared in Synthetic Example 1 above is in the form of a mixture with SONGNOX® L135 (an antioxidant based on isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamate) (composition). [A]、 [B]、 [C] and [D]) Use. Table 1: Analyzed Compositions Composition Amount of isooctyl-3,5-di-tert-butyl-4-methoxy-hydrocinnamate [weight%] [A] (According to the present invention) 1.2% by weight [B] (According to the present invention) 5.8% by weight [C] (According to the present invention) 13.2% by weight [D] (According to the present invention) 24.3% by weight

[0058] Using the above composition, test oils were prepared to investigate the antioxidant properties of the compositions described above. For this purpose, 0.5% by weight of the composition was added to a 50:50 mixture of Yubase 4 and Yubase 6 (a Group III oil mixture) (obtained from SK Lubricants Co. Ltd., Seoul, Korea). The oxidative stability of the obtained lubricant was determined by PDSC (performed according to ASTM D6186 at 180°C). The following results were obtained: Table 2: Results of PDSC Test Oil blends for PDSC 1 2 3 4 Composition A, weight % 0.5 Composition B, weight % 0.5 Composition C, weight % 0.5 Composition D, weight % 0.5 Group III base oil blend, % by weight 99.5 99.5 99.5 99.5 Oxidation induction time (OIT) measured by PDSC [min] 19.7 20.3 26.1 25.4

[0059] As can be seen from the results shown in Table 1, O-alkylated sterically hindered compounds such as isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate are particularly effective antioxidants compared to their corresponding phenolic derivatives.

Claims

1. A composition comprising i) a compound of general formula (I) wherein R1 is a straight-chain or branched C7-C9 alkyl group; R2 is a methyl group; and R3 is a tert-butyl group.

2. The composition of claim 1, wherein R1 is isooctyl or 2-ethylhexyl or both.

3. The composition of claim 1 or 2, wherein the composition comprises at least 0.1% by weight of the compound of general formula (I) based on the total weight of the composition.

4. The composition of claim 3, wherein the composition comprises at least 50% by weight of the compound of general formula (I) based on the total weight of the composition.

5. The composition of claim 4, wherein the composition comprises at least 90% by weight of the compound of general formula (I) based on the total weight of the composition.

6. The composition of claim 1 or 2 further comprises ii) isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrocinnamate.

7. The composition of claim 6, wherein the composition comprises i) at least 0.01% by weight of isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate; ii) at least 25% by weight of isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamate; in each case, the total weight of components i) and ii) in the composition.

8. The composition of claim 7, wherein the composition comprises iii) less than 5% by weight, based on the total weight of components i), ii) and iii) of the composition, a compound selected from the group consisting of: diisooctyl-α-(3,5-di-tertiary butyl-4-hydroxybenzyl) glutarate, di-tertiary butylphenol, methyl-3,5-di-tertiary butyl-4-hydroxyhydrocinnamate and isooctyl alcohol.

9. The composition of claim 8, wherein the composition comprises isooctyl-3,5-di-tertiary butyl-4-methoxy-hydrogenated cinnamic acid ester and diisooctyl-α-(3,5-di-tertiary butyl-4-hydroxybenzyl)glutarate in a weight ratio of at least 2:

1.

10. The composition of claim 6, wherein the composition comprises 1 to 50% by weight of the compound of general formula (I) based on the total weight of the composition.

11. The composition of claim 10, wherein the composition comprises 2.5 to 35% by weight of the compound of general formula (I) based on the total weight of the composition.

12. The composition of claim 6, wherein at least one of the following conditions (α1) to (α5) is satisfied: (α1) the composition has a kinematic viscosity in the range of 60 to 300 cSt (as determined by ASTM D 445 at a temperature of 40°C); (α2) the composition has a Gardner color of less than 10 Gardners (as determined by ASTM D 1544); (α3) the composition has a water content of less than 0.5% by weight (as determined by ASTM E 203); (α4) the composition has a specific gravity in the range of 0.900 to 1.020 (as determined by ASTM D 1298 at a temperature of 25°C); (α5) the composition has a total acid value of less than 5.0 mg KOH / g (as determined by ASTM D664).

13. The composition of claim 1 or 2, wherein the total amount of component i) in the composition is at least 95% by weight based on the total weight of the composition.

14. The composition of claim 6, wherein the total amount of components i) and ii) in the composition is at least 95% by weight based on the total weight of the composition.

15. The composition of claim 1 or 2, wherein the composition is an additive blend.

16. The composition of claim 15, wherein the total amount of component i) in the composition is in the range of 0.01 to 50% by weight, based on the total weight of the additive blend.

17. The composition of claim 6, wherein the composition is an additive blend.

18. The composition of claim 17, wherein the total amount of components i) and ii) in the composition is in the range of 0.01 to 50% by weight, based on the total weight of the additive blend.

19. The composition of claim 1 or 2, wherein the composition is an oil comprising at least one base oil.

20. The composition of claim 19, wherein the total amount of component i) in the composition is in the range of 0.01 to 5% by weight, based on the total weight of the engine oil.

21. The composition of claim 6, wherein the composition is an oil comprising at least one base oil.

22. The composition of claim 21, wherein the total amount of components i) and ii) in the composition is in the range of 0.01 to 5% by weight, based on the total weight of the engine oil.

23. The composition of claim 1 or 2, wherein the composition is a polymer composition comprising a polymer.

24. The composition of claim 23, wherein the total amount of component i) in the composition is in the range of 0.01 to 5% by weight, based on the total weight of the polymer composition.

25. The composition of claim 6, wherein the composition is a polymer composition comprising a polymer.

26. The composition of claim 25, wherein the total amount of components i) and ii) in the composition is in the range of 0.01 to 5% by weight, based on the total weight of the polymer composition.

27. Use of a composition as claimed in any one of claims 1 to 14, for use as an additive in an additive blend, oil, or polymer composition.

28. Use of a compound of general formula (I), wherein R1 is a straight-chain or branched C7-C9 alkyl group; R2 is methyl; R3 is tert-butyl; the compound is used as an additive in additive blends, motor oils or polymer compositions.