O-alkylated sterically hindered oxidation inhibitors

Abstract

The present invention relates to a composition comprising a compound of the general formula (I), wherein R 1 is a linear or branched C1-C24 alkyl group; R 2 is a C1-C8 alkyl group; and R 3 is a C1-C8 alkyl group. The present invention also relates to industrial products, such as additive blends, motor oils and polymer compositions comprising such a compound of the general formula (I), and to the use of said compound of the general formula (I) as in industrial products such as additive blends, motor oils and polymer compositions.

Description

Technical Field

[0001] This invention relates to a composition comprising an O-alkylated steric-resistance oxidant. The invention also relates to a method for preparing the O-alkylated steric-resistance oxidant, an industrial product comprising such a composition, and the use of the O-alkylated steric-resistance oxidant as an additive in the industrial product. Background 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. This oxidation is particularly accelerated when such lubricants are exposed to high temperatures and iron-catalyzed environments. If left uncontrolled, this oxidation promotes the formation of corrosive acidic products, sludge, varnishes, resins, and other oil-insoluble products, and can lead to a loss of the lubricant's intended physical and tribological properties. Therefore, it is customary to include antioxidants in lubricants to at least partially prevent oxidation and extend their service life.

[0003] Lubricating compositions containing various diarylamines or phenolic compounds as antioxidants are widely known in the art. For example, US 5,892,097 discloses the preparation of sterically 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 properties of sterically hindered phenolic compounds obtained by this reaction and known from the prior art can still be improved. Summary of the Invention

[0004] Technical issues

[0005] Therefore, one objective of the present invention is to overcome the disadvantages associated with prior art compositions for improving the properties of industrial products (such as engine oils), particularly in terms of their oxidative stability.

[0006] In particular, an 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, especially in terms of oxidative stability.

[0007] The independent claims help to solve at least one, and preferably more than one, of the aforementioned objectives. The supplementary claims provide preferred embodiments that help to solve at least one of the stated objectives.

[0008] Problem Solution

[0009] The composition helps to solve at least one objective according to the invention, comprising

[0010] i) Compounds of general formula (I)

[0011]

[0012] (I)

[0013] in

[0014] R 1 It 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, most preferably branched octyl, and most preferably isooctyl or 2-ethylhexyl or both;

[0015] R 2 It is a C1-C8 alkyl group, preferably methyl or ethyl, more preferably methyl;

[0016] R 3 It is a C1-C8 alkyl group, preferably a C1-C4 alkyl group, and more preferably a tert-butyl group.

[0017] 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 mixtures of commercially available antioxidants based on isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamate, wherein a certain amount of the corresponding O-alkylated derivative (i.e., isooctyl-3,5-di-tert-butyl-4-alkoxy-hydrogenated cinnamate, preferably isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate) have been added.

[0018] Compounds of general formula (I) can be prepared by a method according to a first embodiment of the present invention, the method comprising the following steps:

[0019] i) Provide compounds of general formula (I)

[0020]

[0021] (I)

[0022] in

[0023] R 1 It 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, most preferably branched octyl, and most preferably isooctyl or 2-ethylhexyl or both;

[0024] R3 It is a C1-C8 alkyl group, preferably a C1-C4 alkyl group, and more preferably a tert-butyl group.

[0025] II) React the compound provided in step I) with at least one alkyl group R 2 The alkylating agent reaction, wherein R 2 It is a C1-C8 alkyl group, preferably methyl or ethyl, more preferably methyl.

[0026] Compounds of general formula (I) can also be prepared by a method according to a second embodiment of the present invention, the method comprising the following steps:

[0027] i) Provide compounds of general formula (I)

[0028]

[0029] in

[0030] R 3 It is a C1-C8 alkyl group, preferably a C1-C4 alkyl group, and more preferably a tert-butyl group.

[0031] R 4 It is a straight-chain or branched C1-C5 alkyl group, preferably methyl;

[0032] II) React the compound provided in step I) with at least one alkyl group R 2 The alkylating agent reaction, wherein R 2 It is a C1-C8 alkyl group, preferably methyl or ethyl, more preferably methyl; and

[0033] III) Reconstitute the compound obtained in step II) with alcohol R 1 -OH reaction, wherein 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, most preferably branched octyl, and most preferably isooctyl or 2-ethylhexyl or both, isooctyl or 2-ethylhexyl in the transesterification reaction using residue R. 1 Substitute residue R 4 .

[0034] A particularly preferred embodiment of the composition according to the invention,

[0035] R 1 It is a C7-C9 alkyl, more preferably a straight-chain or branched C8 alkyl, even more preferably a branched octyl, wherein isooctyl or 2-ethylhexyl or both are most preferred;

[0036] R 2 It is methyl; and

[0037] R 3 It is tert-butyl.

[0038] Therefore, a particularly preferred antioxidant is octyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate (=octyl 3-(3,5-di-tert-butyl-4-methoxyphenyl)propionate), which preferably has one of the following structures:

[0039]

[0040] 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, diazonium chloride, methanol, trimethylsulfonium salts, or tetramethylammonium salts (such as tetramethylammonium hydroxide or tetramethylammonium chloride). For example, a method for O-methylation of phenolic compounds or phenolic derivatives using tetramethylammonium chloride as a methylating agent is disclosed 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.

[0041] In another preferred embodiment of the composition according to the invention, in each case, the composition comprises, by weight of the total composition, at least 0.1 wt%, or at least 1 wt%, or at least 5 wt%, or at least 10 wt%, or at least 20 wt%, or at least 30 wt%, or at least 40 wt%, or at least 50 wt%, or at least 60 wt%, or at least 70 wt%, or at least 80 wt%, or at least 90 wt%, or at least 95 wt%, or at least 99 wt% of a compound of general formula (I), preferably isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamic acid ester. In a specific embodiment of the composition according to the invention, in each case, by weight of the total composition, the content of the compound of general formula (I) in the composition is preferably in the range of 0.1 to 99 wt%, more preferably in the range of 1 to 95 wt%, and even more preferably in the range of 5 to 90 wt%.

[0042] In another specific embodiment of the composition according to the invention, this composition was obtained by supplementing the composition comprising 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).

[0043] According to the specific embodiments of the compositions of the present invention, the compositions therefore further include

[0044] ii) Octyl-3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamate, having one of the various formulas of general structure (II), preferably isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamate:

[0045]

[0046] (II)

[0047] In this particular embodiment of the composition according to the invention, it is further preferred that the composition comprises

[0048] i) at least 0.01 wt%, preferably at least 0.1 wt%, and more preferably at least 1 wt.% of octyl-3,5-di-tert-butyl-4-methoxyhydrocinnamate, preferably isooctyl-3,5-di-tert-butyl-4-methoxyhydrocinnamate, wherein more preferably, the amount of octyl-3,5-di-tert-butyl-4-methoxyhydrocinnamate is less than 35 wt%, preferably less than 25 wt%, and more preferably less than 15 wt%; and

[0049] 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;

[0050] In all cases, the total weight of components i) and ii) in the composition is taken.

[0051] In this particular embodiment of the composition according to the invention, it is further preferred that the composition comprises

[0052] iii) Less than 5% by weight, preferably less than 2.5% by weight, and more preferably less than 1% by weight of compounds selected from the group consisting of:

[0053] -Dioctyl-α-(3,5-di-tert-butyl-4-hydroxybenzyl)glutarate, preferably dioctyl-α-(3,5-di-tert-butyl-4-hydroxybenzyl)glutarate having formula (III), wherein R x and R y The groups selected independently of isooctyl and 2-ethylhexyl are most preferably diisooctyl-α-(3,5-di-tert-butyl-4-hydroxybenzyl)glutarate.

[0054]

[0055] (III)

[0056] -di-tert-butylphenol

[0057] 3,5-Di-tert-butyl-4-hydroxy-hydrogenated cinnamate

[0058] -Dimethyl-α-(3,5-di-tert-butyl-4-hydroxybenzyl)glutarate, and

[0059] - Alcohol, preferably octanol, more preferably isooctyl alcohol.

[0060] In all cases, the total weight of components i), ii) and iii) in the composition is taken.

[0061] 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.

[0062] 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 wt%, preferably 1.5 to 45 wt%, more preferably 2 to 40 wt%, more preferably 2.5 to 35 wt%, more preferably 3 to 30 wt%, more preferably 3.5 to 25 wt%, and even more preferably 4 to 20 wt% of a compound of general formula (I), preferably isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate.

[0063] In this particular embodiment of the composition according to the invention, it is also preferred that at least one of the following conditions (a1) to (a5) is satisfied, and preferably all of the following conditions (a1) to (a5) are satisfied:

[0064] (al) The composition has a kinematic viscosity (measured at 40°C according to ASTM D 445) 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.

[0065] (a2) The composition has a Gardner color of less than 10 Gardner, preferably less than 5 Gardner, and more preferably less than 3 Gardner (as determined according to ASTM D 1544).

[0066] (a3) 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);

[0067] (a4) 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 more preferably in the range of 0.940 to 1.000 (measured according to ASTM D 1298 at 25°C);

[0068] (a5) The composition has a total acid value 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 (as determined by ASTM D664).

[0069] 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 include component ii) or the total amount of components i) and ii (if the composition includes 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).

[0070] In a second variant of the composition according to the invention, the composition is a lubricant or a lubricating composition. In this second variant 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 different 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 the form of such an additive package.

[0071] 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 include component ii) or the total amount of components i) and ii (if the composition includes component ii) is in the range of 0.01 to 95% by weight, preferably in the range of 0.1 to 60% by weight, and more preferably in the range of 0.5 to 30% by weight, based on the total weight of the additive blend.

[0072] In a third variation of the composition according to the invention, the composition is a motor oil comprising at least one base oil. In this third variation 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 include component ii) or the total amount of components i) and ii) (if the composition includes component ii) is in the range of 0.01 to 10% by weight, preferably in the range of 0.05 to 5% by weight, and more preferably in the range of 0.1 to 2% by weight, based on the total weight of the motor oil.

[0073] In a fourth variation of the composition according to the 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), nitrile rubber (NBR)) or a mixture thereof, or a mixture comprising at least two of these polymers. In this fourth variation 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 include component ii) or the total amount of components i) and ii) (if the composition includes component ii) is in the range of 0.01 to 10% by weight, preferably in the range of 0.05 to 2.0% by weight, and more preferably in the range of 0.1 to 1.0% by weight, based on the total weight of the polymer composition.

[0074] In this fourth variant of the composition according to the invention, it is particularly preferred that 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 mono- and diene unsaturated hydrocarbon monomers of C3 and higher carbon, such as polypropylene, polyisobutylene, polymethylbutene-1, polymethylpentene-1, polybutene-1, polyisobutylene, 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 engineered thermoplastics, such as polyamides, polyesters, polyphenylene ether, polyphenylene sulfide, polyacetals, aliphatic polyketide copolymers or terpolymers, poly(ether sulfone), 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 polyurethane or polypropylene.

[0075] 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 foam, the composition according to the invention can be added to a polyol that subsequently reacts with an isocyanate to form a polyurethane.

[0076] Furthermore, the use of compounds of the following general formula (I) facilitates the resolution of at least one objective according to the invention.

[0077]

[0078] in

[0079] R 1It 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, most preferably branched octyl, and most preferably isooctyl or 2-ethylhexyl or both;

[0080] R 2 It is a C1-C8 alkyl group, preferably methyl or ethyl, more preferably methyl; and

[0081] R 3 It is a C1-C8 alkyl group, preferably a C1-C4 alkyl group, and more preferably a tert-butyl group;

[0082] The compound is used as an additive in a lubricant composition, preferably in an engine oil, or in a polymer composition or both. The compound of general formula (I) is preferably isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate. Detailed Implementation

[0083] Additives in the additive blends according to the present invention

[0084] The additive blends (or additive packages) according to the invention are blends for treating industrial and automotive lubricants, comprising, in addition to base oils, 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), preferably compositions comprising isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamic acid ester, may therefore be part of such additive packages.

[0085] In the additive blend, in addition to compositions comprising compounds of general formula (I), preferably in addition to compositions comprising isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamic acid ester, a suitable antioxidant may be present, selected from:

[0086] 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-di-octadecyl-4-methylphenol, 2,4,6-Tricyclohexylphenol, 2,6-di-tert-butyl-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;

[0087] 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;

[0088] 3) Hydroquinone and alkylated hydroquinone, such as 2,6-di-tert-butyl-4-methoxy-phenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-pentylhydroquinone, 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-hydroxyphenyl stearate or bis(3,5-di-tert-butyl-4-hydroxyphenyl) adipate;

[0089] 4) Tocopherols, such as α-tocopherol, β-tocopherol, γ-tocopherol or δ-tocopherol or mixtures thereof (vitamin E);

[0090] 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-pentylphenol) or 4,4'-bis(2,6-di-methyl-4-hydroxyphenyl) disulfide;

[0091] 6) Methalkyl 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'- Ethylene-bis(4,6-di-tert-butylphenol), 2,2'-ethylene-bis(6-tert-butyl-4-isobutylphenol), 2,2'-methylene-bis(6-(a-methylbenzyl)-4-nonylphenol), 2,2'-methylene-bis(6-(a,a-dimethyl-benzyl)-4-nonylphenol), 4,4'-methylene-bis(2,6-di-tert-butylphenol), 4,4'-methylene-bis(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-dodecyl mercaptobutane, ethylene glycol bis(3,3-bis(3'-tert-butyl-4'-hydroxyphenyl)butyrate), bis(3-tert-butyl-4-hydroxy-5-methylphenyl)bicyclo Pentadiene, 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-dodecyl mercaptobutane or 1,1,5,5-tetra(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane;

[0092] 7) O-benzyl compounds, N-benzyl compounds and S-benzyl compounds, such as 3,5,3',5'-tetra-tert-butyl-4,4'-dihydroxy-dibenzyl ether, octadecyl 4-hydroxy-3,5-dimethylbenzyl mercaptoacetate, tridecyl 4-hydroxy-3,5-di-tert-butylbenzyl mercaptoacetate, 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-benzyl mercaptoacetate;

[0093] 8) Hydroxybenzylated malonates, such as 2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate di(octadecyl) ester, 2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate di(octadecyl) ester, mercaptoethyl-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate d-dodecyl ester or di(4-(1,1,3,3-tetramethylbutyl)phenyl)-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate;

[0094] 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;

[0095] 10) Triazine compounds, such as 2,4-bisoctylmercapto-6-(3,5-di-tert-butyl-4-hydroxyaniline)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyaniline)-1,3,5-triazine, 2-octylmercapto-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;

[0096] 11) Benzylphosphonates, 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 calcium salts of monoethyl esters of 3,5-di-tert-butyl-4-hydroxybenzylphosphonate;

[0097] 12) Amide-based phenols, such as 4-hydroxylauroyl aniline, 4-hydroxystearoyl aniline, or octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate;

[0098] 13) 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 with monohydric or polyhydric alcohols (e.g., methanol, ethanol, n-octanol, isooctyl alcohol, stearyl alcohol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2 Esters formed by the reaction of propylene glycol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tri(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)oxalamide, 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 rapeseed oil;

[0099] 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)hexanediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine or N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine;

[0100] 15) Ascorbic acid (vitamin C);

[0101] 16) Amine-type 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(l-ethyl-3-methyl-pentyl)-p-phenylenediamine, N,N'-bis(l-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-(l-methylheptyl)-N'-phenyl-p-phenylenediamine, N... -cyclohexyl-N'-phenyl-p-phenylenediamine, 4-(p-toluenesulfonylamino)diphenylamine, N,N'-dimethyl-N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyl diphenylamine, 4-isopropoxy-diphenylamine, 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, di-(4-methoxyphenyl)-amine, 2,6-di-tert-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-(phenylamino)propane, (o-tolyl)biguanide, di(4-(1',3'-dimethyl-butyl)-phenyl)-amine, tert-octylated N-phenyl-1-naphthylamine, mixtures of monoalkylated and dialkylated tert-butyl / tert-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, mixtures of monoalkylated and dialkylated tert-butyl diphenylamine, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine, mixtures of monoalkylated and dialkylated tert-butyl / tert-octylphenothiazine, mixtures of monoalkylated and dialkylated tert-octyl-phenothiazine, 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

[0102] 17) Aliphatic or aromatic phosphites, thiodipropionates or thiodiacetic acids, or dithiocarbamates or dithiophosphates, 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.

[0103] Suitable anti-wear additives are selected from:

[0104] 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...

[0105]

[0106] Where R and R' independently represent C1-C 20 Alkyl, C3-C 20 alkenyl, C5-C 12 cycloalkyl, C7-C 13 Aryl or C6-C 10 Aryl groups, such as R and R', are independently C1-C. 12 Alkyl groups; and

[0107] 2) Sulfur- and / or phosphorus- and / or halogen-containing compounds, such as sulfurized alkenes and vegetable oils, tritolyl phosphate, tricresyl phosphate, chlorinated alkanes, alkylated and arylated disulfides and trisulfides, monoalkyl phosphate amine salts and dialkyl phosphate amine salts, methylphosphonic acid amine salts, diethanolaminomethyltolyltriazole, di(2-ethylhexyl)aminomethyltolyltriazole, 2,5-dimercapto-1,3,4-thiadiazole derivatives, ethyl ((bisisopropoxythiophosphoryl)thio)propionate, triphenyl thiophosphate. thiophosphate / triphenylphosphorothioate), tri(alkylphenyl) thiophosphate and mixtures thereof (e.g., tri(isononylphenyl) thiophosphate), diphenylmononylphenyl thiophosphate, isobutylphenyl diphenyl thiophosphate, 3-hydroxy-1,3-thiaphosphazene-3-dodecylamine salt, 5,5,5-tris(2-acetic acid isooctyl ester) trithiophosphate, 2-mercaptobenzothiazole derivatives such as 1-(N,N-bis(2-ethylhexyl)aminomethyl)-2-mercapto-1H-1,3-benzothiazole or 5-octyl dithiocarbamate ethoxycarbonyl ester.

[0108] Suitable dispersants are selected from:

[0109] 1) Mannich base as a condensation product of high molecular weight phenol, propyne polyamine and aldehyde (such as formaldehyde);

[0110] 2) As a succinic acid-based dispersant for further reaction of the reaction product of olefin polymers with succinic acid acylating agents (acids, anhydrides, esters, or halides) with organic hydroxyl compounds and / or amines; and

[0111] 3) High molecular weight amides and esters, such as the reaction products of hydrocarbon acylating agents and polyaliphatic alcohols (such as glycerol, pentaerythritol or sorbitol).

[0112] Ashless (metal-free) polymers containing an oil-soluble, high-molecular-weight backbone linked to polar functional groups associated with the particles to be dispersed are commonly used as dispersants. Commonly used hydrocarbon backbone materials are olefin polymers and copolymers, namely ethylene, propylene, butene, isobutylene, 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.

[0113] 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. The salts may be neutral or excessively alkalized, for example, by metal hydroxides or carbonates.

[0114] Suitable defoamer additives are selected from silicone oil, polysiloxane, and polyethylene glycol ether.

[0115] 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.

[0116] Suitable copper passivating agents are selected from:

[0117] 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;

[0118] 2) Imidazole derivatives, such as 4,4'-methylenebis(2-undecyl-5-methyl-imidazolium) and bis((N-methyl)imidazol-2-yl)methanol octyl ether;

[0119] 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-thiadiazolin-2-one; and

[0120] 4) Amino compounds, such as salicylpropyl diamine, salicylaminoguanidine or their salts.

[0121] Suitable rust inhibitors are selected from:

[0122] 1) Nonionic polyethylene glycol and its esters, polyoxyphenols, organic acids, their esters, metal salts, amine salts and acid anhydrides, such as alkyl succinic acid and alkenyl succinic acid and their partial esters with alcohols, glycols or hydroxycarboxylic acids, alkyl succinic acid and alkenyl succinic acid, 4-nonylphenoxyacetic acid, alkoxycarboxylic acid and alkoxyethoxycarboxylic acid partial amides, such as dodecyloxyacetic acid, dodecyloxy(ethoxy)acetic acid and their amine salts, or N-oleoylsarcosine, sorbitol monooleate, lead naphthate and alkenyl succinic anhydride, such as dodecyl alkenyl succinic anhydride, 2-(2-carboxyethyl)-1-dodecyl-3-methylglycerol and their salts, such as sodium salts and triethanolamine salts;

[0123] 2) Selected from the following nitrogen-containing compounds: i) aliphatic or cycloaliphatic primary, secondary or tertiary 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 oxazolines, such as 2-heptadecenyl-l-(2-hydroxyethyl)-imidazoline;

[0124] 3) Phosphorus-containing compounds, such as ammonium phosphates, metaphosphates or phosphonates or zinc dialkyl dithiophosphates;

[0125] 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

[0126] 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.

[0127] Suitable flow point depressants are selected from polymethacrylates and alkylated naphthalene derivatives.

[0128] Suitable demulsifiers are selected from polyether polyols and dinonylnaphthalene sulfonate.

[0129] Suitable friction modifiers are selected from fatty acids and their derivatives, such as natural fatty acid esters, such as glyceryl monooleate, amides, imides and amines, such as oleylamine, sulfur-containing dithiocarbamate organic molybdenum, sulfur-containing phosphorus dithiophosphate organic molybdenum, dispersant-based sulfur-containing nitrogen organic molybdenum compounds, carboxylate molybdenum salts, molybdenum amine complexes, molybdenum amine / alcohol / amide complexes and molybdenum clusters. And molybdenum disulfide.

[0130] The base oil in the lubricant according to the present invention

[0131] The lubricant according to the invention, preferably an engine oil, comprises at least one base oil (i.e., a lubricant having a lubricating viscosity) and a composition comprising a compound of general formula (I) according to the invention, preferably a composition comprising isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamic acid ester.

[0132] Suitable base oils are mineral oils 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.

[0133] The base oil can be oils and fats, 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 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 (e.g., epoxidized or sulfoxide-treated) forms, or genetically engineered forms, such as genetically engineered soybean oil.

[0134] Examples of synthetic base oils include lubricants based on: aliphatic or aromatic carboxylic acid esters, polymeric esters, polyepoxides, phosphate esters, poly-α-olefins, silicones, alkylbenzenes, alkylnaphthalenes, or diesters of diacids and monohydric alcohols (e.g., dioctyl sebacate or dinonyl adipate), triesters of trimethylolpropane and monohydric acids or mixtures thereof (e.g., tripelargonate, trimethylolpropane-trioctanoate, or mixtures thereof), tetraesters of pentaerythritol and monohydric acids or mixtures thereof (e.g., pentaerythritol tetraoctanoate), or complex esters of monohydric acids and diacids with polyhydric alcohols (e.g., 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 polyalkylene glycols and mixtures thereof with water.

[0135] When other additives are used 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 cinnamate, it may be necessary, though not necessary, to prepare an additive concentrate in the form of the above-described additive blend (or additive package), said additive concentrate comprising a concentrated solution or dispersion of a composition containing a compound of general formula (I) according to the invention, preferably a concentrated solution or dispersion comprising isooctyl-3,5-di-tert-butyl-4-methoxy-hydrogenated cinnamate and one or more of the other additives, thereby allowing the simultaneous addition of several additives to a base oil to form a lubricating oil composition. The dissolution of the additive concentrate in the lubricating oil can be promoted by solvent and by mixing accompanied by slight heating, but this action 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 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 containing an active ingredient, the total amount of which is typically about 2.5 to about 90% by weight, preferably about 15 to about 75% by weight, and more preferably about 25 to about 60% by weight of additive, in appropriate proportion to the remainder of the base oil. The final formulated product may typically consist of about 1 to 20% by weight of the additive blend, with the remainder being the base oil.

[0136] Polymer in the polymer composition according to the present invention

[0137] 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 further comprise polymers (preferably thermoplastic polymers, rigid plastic polymers), elastomers, polyols, rubbers (such as butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene propylene rubber (EPR), nitrile rubber (NBR)) or mixtures thereof, or mixtures comprising at least two of these polymers.

[0138] Compositions comprising compounds of general formula (I) according to the invention can be used to stabilize thermoplastic polymers resistant to oxidative decomposition, including resins derived from ethylene, 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 g / cm³. 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, polyisobutylene, 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 their blends, polystyrene; polyhalogenated ethylene; and engineered thermoplastics, such as polyamides, polyesters, polyphenylene ethers, polyphenylene sulfides, polyacetals, aliphatic polyketide copolymers or terpolymers, poly(ether sulfone), polycarbonate, liquid crystal polymers, poly(ether ether ketone), polyurethane, and poly(aryl esters). Preferably, the thermoplastic resin protected by the composition according to the invention is a polyurethane or polypropylene.

[0139] The invention will now be described in more detail with reference to test methods and non-limiting embodiments.

[0140] Implementation

[0141] Test methods

[0142] Determination of oxidative stability

[0143] Oxidative stability was assessed using a pressurized differential scanning calorimetry (PDSC) device.

[0144] PDSC was used to examine the oxidative stability of oils under thin-film oxidation conditions. In isothermal mode with the PDSC temperature maintained at a predetermined value, the oxidative stability of the tested 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.

[0145] The following measurement conditions have been selected:

[0146] Temperature ramp: 40℃ / min

[0147] Pressure: 500 psi

[0148] O2 flow rate: 100 ml / min

[0149] Sample amount: approximately 1.5 mg

[0150] Plate: Aluminum, open

[0151] Example

[0152] Synthesis Example 1

[0153]

[0154] 3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropionic acid-C7-9-branched alkyl ester, KOH, and iodomethane were stirred in acetone for 18 hours at room temperature. The reaction mixture was concentrated under vacuum, and the residue was partitioned between ethyl acetate and H2O. The aqueous phase was extracted three times with ethyl acetate, and the organic matter was combined, dried (MgSO4), and concentrated under vacuum. The product was obtained by distillation of the crude product.

[0155] Synthesis Example 2

[0156]

[0157]

[0158] Methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, KOH, and iodomethane were stirred in acetone for 18 hours at room temperature. The reaction mixture was concentrated under vacuum, and the residue was partitioned between ethyl acetate and H₂O. The aqueous phase was extracted three times with ethyl acetate, and the organic matter was combined, dried (MgSO₄), and concentrated under vacuum to obtain a composition comprising methyl 3-(3,5-di-tert-butyl-4-methoxyphenyl)propionate.

[0159] 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 concentrated under vacuum. The product was obtained by distillation of the crude product.

[0160] Example 1:

[0161] The isooctyl-3,5-di-tert-butyl-4-methoxy-hydrocinnamate prepared in Example 1 above is based on... LI35 (which is an antioxidant based on isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamic acid ester) is used in the form of a mixture (compositions A, B, C and D).

[0162] [Table 1]

[0163] 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

[0164] Using the above composition, test oils were prepared to investigate the antioxidant properties of the composition 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 (Class III - oil mixture) (obtained from SK Lubricants Co. Ltd., Seoul, Korea). Oxidative stability (by PDSC, performed at 180°C according to ASTM D6186) was determined from the resulting lubricant. The following results were obtained:

[0165] [Table 2]

[0166] Composition A, wt.% 0.5 Composition B, wt.% 0.5 Composition C, wt.% 0.5 Composition D, wt.% 0.5 Group III base oil blend, wt.% 99.5 99.5 99.5 99.5 <![CDATA[Oxidation induction time (OIT) determined by PDSC 1) [min]]]> 19.7 20.3 26.1 25.4

[0167] 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) Compounds of general formula (I) in R 1 It is a C7-C9 alkyl group; R 2 It is methyl; and R 3 It is tert-butyl.

2. The composition according to claim 1, wherein... R 1 It is isooctyl or 2-ethylhexyl or both.

3. The composition according to 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 according to 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 according to any one of claims 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 according to claim 2, further comprising: ii) Isooctyl-3,5-di-tert-butyl-4-hydroxy-hydrocinnamate.

7. The composition according to 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 all cases, the total weight of components i) and ii) in the composition shall be used.

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

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

1.

10. The composition according to 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 according to 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 according to claim 6, wherein at least one of the following conditions (a1) to (a5) is satisfied: (al) The composition has a kinematic viscosity in the range of 60 to 300 cSt (measured at 40°C according to ASTM D 445); (a2) The composition has a Gardner color intensity of less than 10 Gardners (as determined according to ASTM D 1544); (a3) The composition has a water content of less than 0.5% by weight (as determined according to ASTM E 203); (a4) The composition has a specific gravity in the range of 0.900 to 1.020 (measured according to ASTM D 1298 at a temperature of 25°C); (a5) The composition has a total acid value of less than 5.0 mg KOH / g (as determined by ASTM D664).

13. The composition according to claim 1 or 6, wherein the total amount of component i) or 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.

14. The composition according to claim 1 or 6, wherein the composition is an additive blend.

15. The composition according to claim 14, wherein the total amount of component i) or 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.

16. The composition according to claim 1 or 6, wherein the composition is a machine oil comprising at least one base oil.

17. The composition according to claim 16, wherein the total amount of component i) or 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.

18. The composition according to claim 1 or 6, wherein the composition is a polymer composition comprising a polymer.

19. The composition according to claim 18, wherein the total amount of component i) or 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.

20. Use of a composition according to any one of claims 1 to 13 as an additive in an additive blend, engine oil, or polymer composition.

21. Use of a compound of general formula (I) as an additive in additive blends, engine oils, or polymer compositions. in R 1 It is a C7-C9 alkyl group; R 2 It is methyl; and R 3 It is tert-butyl.

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