LUBRICANT COMPOSITION AND ITS USE

Description

[0001] The present invention relates to lubricant compositions and their use as gear, rolling bearing and sliding bearing oil for general industry as well as in the marine sector and in inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media.

[0002] When using lubricants or lubricant compositions as gear, rolling bearing, and plain bearing oils for general industry, the challenge lies in ensuring both excellent tribological properties in the gear teeth and very good compatibility of the lubricant with sealing materials. Radial shaft seals, typically made of elastomers such as FKM (fluoroelastomer), NBR ( nitrile butadiene rubber ) , HNBR ( hydrogenated nitrile butadiene rubber ) , ACM / AEM ( acrylate elastomers / ethylene acrylic elastomers) and polyurethanes are used. The importance of the lubricant's compatibility with the seals is demonstrated by the frequency of gearbox, plain bearing, and rolling bearing failures. The proportion of gearbox, plain bearing, and rolling bearing failures due to incompatibility between lubricant and sealing material is significantly higher than the proportion of gearbox, plain bearing, and rolling bearing failures due to, for example, galling. Therefore, the selection of the base oil component(s) for the lubricant, as well as the carefully matched selection of additives, is essential to prevent damage to sealing materials while still achieving excellent tribological properties. Another problem is that many lubricants used in general industry are not suitable for occasional, unintentional contact with food, e.g., in food processing applications.They do not have H1 certification according to NSF Code of Federal Regulations §21 CFR 178.3570. Examples of lubricant compositions are disclosed in US 2008 / 280795 A1 and US 2009 / 042752 A1.

[0003] Therefore, there is a need for new lubricants or lubricant compositions for use as gear, rolling bearing or sliding bearing oil for general industry, which exhibit high compatibility with sealing materials, especially elastomer materials, and at the same time have good tribological properties, so that they improve sliding behavior, reduce the stick-slip effect, especially in frictional contact under high load and low speeds, and have a positive influence on the micropitting capacity.

[0004] Furthermore, in practice it would be desirable if these lubricant compositions were also minimally toxic and, according to NSF / H1 certification, permissible for occasional, unintentional food contact, so that they are suitable for applications in the food processing industry.

[0005] When lubricants or lubricant compounds are used in marine and inland water applications—that is, applications where the lubricants or lubricant compounds are typically used below the waterline in oil-to-water interfaces—there is a risk of contaminating the marine or aquatic environment through lubricant leakage, for example. Although every effort is made to seal the water side as effectively as possible in these applications, lubricant losses are commonplace. The demand for environmentally friendly lubricants to reduce chemical pollution of the seas and inland waters is therefore increasing dramatically. However, the demand for environmentally friendly lubricants is also rising on land, as soil contamination by chemicals is playing an increasingly significant role.Components used on land can come into contact with water, for example through rain. Furthermore, leaks are also possible, which can lead to environmental and soil contamination. There is a high demand for environmentally friendly lubricants on land, particularly in the mining industry, wind turbines, and agricultural machinery.

[0006] In recent years, environmental protection has become increasingly important, especially the protection of the oceans. For example, the [relevant authority / organization] requires [specific regulations / standards] for lubricants used below the waterline in oil-to-water interfaces. Vessel General Permit (VGP) United States Environmental Protection AgencyThe use of so-called Environmentally Acceptable Lubricants (EALs) requires meeting stringent requirements regarding biodegradability and aquatoxicity. Common EALs are therefore manufactured using natural and synthetic esters, instead of the traditional mineral oil-based lubricants. However, compared to mineral oil-based lubricants, the use of EALs often leads to damage to sealing materials and significant performance losses in terms of sliding or lubrication behavior due to their comparatively lower stability.

[0007] There is therefore a need for biocompatible lubricants, meaning readily biodegradable and minimally aquatoxic, that exhibit high compatibility with sealing materials, especially elastomers, particularly for use as gear, rolling bearing, and sliding bearing oils in marine and inland waters. This also includes applications in land-based machinery and machine components that may come into contact with water and / or aqueous media.

[0008] Compared to mineral oil-based lubricants, the use of EALs (Energy-Associated Lubricants) is associated with a higher incidence of problems in stern tube lubrication. There is strong evidence suggesting that the use of EALs leads to insufficient lubrication of the bearing at low speeds and high loads. It is known that insufficient lubrication can also occur at other lubrication points. These include, for example, all plain bearings, gears, linear guides, pneumatic components, fittings, rolling bearings, chains, ropes, springs, and screws. In this context, there is also a need for new biocompatible lubricants for use as gear, rolling bearing, and plain bearing oils in marine and inland waterways, as well as in land-based machinery and machine components that may come into contact with water and / or aqueous media, and which also improve sliding properties.

[0009] The object of the present invention was therefore to provide lubricants or lubricant compositions that exhibit improved compatibility with sealing materials, in particular elastomers, and have excellent tribological properties, resulting in improved sliding behavior, a reduction of the stick-slip effect, and a positive influence on the micropitting load-bearing capacity, and which are suitable for use as gear, rolling bearing and sliding bearing oil for general industry.

[0010] A further object of the present invention was to provide minimally toxic, i.e. NSF / H1 certified, lubricants suitable for use as gear, rolling bearing and sliding bearing oils for general industry including applications in the food processing industry, and which also exhibit the aforementioned advantageous properties with regard to sealing compatibility and sliding behavior.

[0011] Furthermore, the object of the present invention was to provide biocompatible, i.e. readily biodegradable and minimally aquatoxic, lubricants that exhibit improved compatibility with sealing materials, in particular elastomers, and simultaneously improve sliding and lubricating behavior, and that are suitable for use as gear, rolling bearing and sliding bearing oil in marine and inland waters as well as in machines and machine elements on land that may come into contact with water and / or aqueous media.

[0012] One or more of the aforementioned problems are solved according to the invention by a lubricant composition as defined in independent claim 1, or by its use according to independent claim 7 or 8. Preferred embodiments of the lubricant composition according to the invention are defined in dependent claims 1 to 6.

[0013] Surprisingly, it was found that the presence of an organic compound, in addition to the other components in the lubricant composition, where the organic compound comprises both a polar and a nonpolar part and meets the requirements for both the relative permittivity εr (in the range of 1.5 to 10) and the ratio ∫S1 / ∫S2 (in the range of 1 to 25), significantly improves the sliding behavior between two friction partners, for example, metal / metal or metal / elastomer (e.g., FKM or NBR). The organic compound is therefore referred to here as a "glide improver".

[0014] For the purposes of this invention, the terms lubricant composition, lubricant, and formulation are used synonymously.

[0015] For the purposes of the present invention, the organic compound is selected from maleic acid-olefin copolymers. Accordingly, for the purposes of the invention, a polymer (homopolymer) is understood to be a molecule or chemical compound composed of a large number, in particular more than ten, structurally identical or similar organic units (monomers) and, in particular, having a weight-average molar mass (Mw) of about 1000 or more. A copolymer is understood to be a polymer composed of two or more different types of monomer units.

[0016] According to the invention, the organic compound C) contains both a polar and a nonpolar part, that is, it is composed of one or more identical or different polar molecular parts and one or more identical or different nonpolar molecular parts, resulting in a certain relative polarity.

[0017] According to the invention, the organic compound C) has a relative permittivity ε r in the range of 1.5 to 10, preferably 1.7 to 8, particularly preferably 2 to 7, and most preferably 2.3 to 5.

[0018] The relative permittivity εr of a medium, also called the permittivity or dielectric constant, is the dimensionless ratio of its permittivity εr to the permittivity ε0 of a vacuum: εr = εr / ε0. Permittivity, also called dielectric conductivity, describes a material property of electrically insulating, polar or nonpolar substances, so-called dielectrics, and indicates the permeability of a material to electric fields. The relative permittivity is a measure of the field-weakening effects of the dielectric polarization of the material.

[0019] The organic compound C) contained in the lubricant composition according to the invention is further characterized in that it has a quotient ∫ S 1 / ∫ S 2 which is in the range of 1 to 25, preferably from 1.3 to 22, particularly preferably 1.7 to 17, and most preferably from 2 to 14.

[0020] Here, "∫ S 1 " denotes the sum of the area(s) of the IR absorption band(s) in the wavenumber range 3100-2750 cm -1< in an ATR spectrum of the organic compound, and "∫ S 2 " denotes the sum of the area(s) of the IR absorption band(s) in the wavenumber range 1800-1650 cm -1< in an ATR spectrum of the organic compound.

[0021] Those skilled in the art know that ATR infrared spectroscopy is a measurement technique suitable for solid and liquid samples and is now the dominant IR technique in many fields. Unlike the classical IR measurement method, which measures the transmittance of a sample, ATR infrared spectroscopy is based on the principle of total internal reflection (ATR, attenuated total reflection, see NJ Harrick: Internal Reflection Spectroscopy. John Wiley & Sons Inc, 1967, ISBN 0-470-35250-7). The resulting spectra are similar to those obtained in transmission spectroscopy. Although the IR absorption bands in ATR spectra become broader and more intense at longer wavelengths (lower wavenumber) than in corresponding transmission spectra, it is known that the positions of the IR absorption bands are identical in transmission and ATR spectra. From spectral databases and tables of vibrational data of important atomic groups (e.g.Helmut Günzler, Hans-Ulrich Gremlich: IR Spectroscopy: An Introduction. 4th edition. Wiley-VCH, Weinheim 2003, pp. 165-240) It is known to those skilled in the art that in a transmission or ATR spectrum in the wavenumber range of approximately 1800-1650 cm⁻¹, in particular the characteristic IR absorption band of the CO stretching vibration (stretching vibration) of the carbonyl group of carbonyl compounds lies, and that in a transmission or ATR spectrum in the wavenumber range of approximately 3100-2750 cm⁻¹, in particular the characteristic IR absorption band of the CH stretching vibration (stretching vibration) of a group -CH₂ x (x = 1, 2 or 3, number of bonded hydrogen atoms) in aliphatic or aromatic hydrocarbons lies.

[0022] The ratio ∫ S₁ / ∫ S₂ thus relates the absorption in the wavenumber range 3100–2750 cm⁻¹, caused predominantly by nonpolar molecular components of the organic compound, to the absorption in the wavenumber range 1800–1650 cm⁻¹, caused predominantly by polar molecular components of the organic compound. The ratio ∫ S₁ / ∫ S₂ can therefore be interpreted as a measure of the polarity of the organic compound contained in the lubricant composition, which includes both polar and nonpolar components.

[0023] The amount of organic compound C) in the lubricant composition is 0.001 wt.% or more, preferably 0.05 wt.% or more, for example 0.1 wt.% or more, and 5 wt.% or less, based on the total weight of the lubricant composition, in order to achieve optimal elastomer compatibility and sliding properties.

[0024] For example, in embodiments of the invention that are particularly suitable for use as gear, rolling bearing and sliding bearing oil for general industry, including in the food processing industry for occasional, unintentional food contact, it is particularly preferred if the amount of organic compound C) is 0.001-2.5 wt.%, and most preferably 0.05-1 wt.%, based on the total weight of the lubricant composition, in order to achieve optimal elastomer compatibility and sliding effect.

[0025] For example, in embodiments of the invention that are particularly suitable for use as gear, rolling bearing and sliding bearing oil in marine and inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media, it is particularly preferred if the amount of organic compound C) is 0.1-5 wt.%, and most preferably 0.1-3 wt.%, based on the total weight of the lubricant composition, in order to achieve optimal elastomer compatibility and sliding effect.

[0026] By adding the organic compound, which comprises both a polar and a nonpolar part and fulfills the aforementioned requirements for both the relative permittivity εr (in the range of 1.5 to 10) and the ratio ∫S1 / ∫S2 (in the range of 1 to 25), in addition to the other components of the lubricant composition, such as base oil(s) or additive(s), a surprising improvement in sliding and lubrication behavior can be achieved, particularly at low gear and bearing speeds and under high loads. Furthermore, the organic compound contributes to improving the compatibility of the lubricant composition according to the invention with elastomeric materials such as FKM and NBR.

[0027] In one embodiment of the invention, the organic compound C) additionally has NSF / H1 certification, so that it can be used in lubricants that are used as gear, rolling bearing and sliding bearing oil for occasional, unintentional food contact in the food processing industry.

[0028] In a further embodiment of the invention, the organic compound C) is an organic compound that is additionally biodegradable (e.g., according to OECD Test Guideline 301 AF or OECD 306) and / or exhibits low aquatoxicity (e.g., according to OECD Test Guidelines 201, 202, 203, or 236). This makes the organic compound suitable for use in lubricants employed as gear, rolling bearing, and sliding bearing oils in marine and inland waters, as well as in machinery and machine components on land that may come into contact with water and / or aqueous media.

[0029] According to the invention, the organic compound that can advantageously be used as a lubrication improver in the lubricant composition according to the invention is selected from maleic acid-olefin copolymers (commercially available, for example, as Ketjenlube® < 135, Ketjenlube® < 2700, Ketjenlube® < 23000). Other exemplary, but not in accordance with the invention, organic compounds are modified polyesters (commercially available, for example, as Perfad™ < 3000, Perfad™ < 3050); polymethyl methacrylate (PMMA), linear polymers, and star polymers (commercially available, for example, as Lubrizol 87725); oleic acid, in particular mixtures of C16-C18 fatty acids and C18 unsaturated fatty acids (commercially available, for example, as Herwemag OA). Glycerol monooleates (GMO), especially those with a mono content of at least 40%, free glycerol max. 6% (commercially available e.g. as Ilco Lube 2316); polymethacrylate (PMA), linear polymers and comb polymers (commercially available e.g.as Viscoplex ®< 3-200); comb polymers of 1-decene and 9-dodecyl methyl ester (commercially available e.g. as Elevance Aria ®< WTP 40); pentaerythritol tetraisostearate (commercially available e.g. as Priolube ™< 3987-LQ).

[0030] The lubricant composition according to the invention contains as a further component A) a base oil component.

[0031] The base oil is selected from estolides; polyalphaolefins (PAOs), metallocene polyalphaolefins (mPAOs), white oils, mineral oils, and farnesene-based oils; as well as polyglycols, in particular polybutylene glycols, polypropylene glycols, polyethylene glycol and their copolymers, which are oil-soluble and preferably water-soluble and / or water-miscible; as well as mixtures of two or more thereof.

[0032] For the purposes of the invention, the term "complex ester" refers in particular to esters in the production of which, for example, dicarboxylic acids (i.e., divalent carboxylic acids) are used alongside monocarboxylic acids (i.e., monovalent carboxylic acids) and polyols.

[0033] According to a particularly preferred embodiment of the lubricant composition according to the invention, especially when the lubricant composition is used as a gear, rolling bearing and sliding bearing oil for general industry, the base oil is selected from polyalphaolefins (PAOs), metallocene polyalphaolefins (mPAOs), white oils, mineral oils, and water-soluble, water-miscible and oil-soluble polyglycols, as well as mixtures of two or more of these.

[0034] It is particularly preferred if the base oil has NSF / H1 certification to enable the lubricant composition to be used as a gear, rolling bearing and sliding bearing oil for occasional, unintentional food contact in the food processing industry.

[0035] According to another particularly preferred embodiment of the present invention, the base oil is selected from polyalphaolefins (PAOs), metallocene polyalphaolefins (mPAOs), white oils, farnesene-based oils, estolides, and oil-soluble polyglycols, as well as mixtures of two or more thereof. These base oils are advantageous with regard to their biodegradability (i.e., biodegradable, for example, according to OECD Test Guideline 301 AF or OECD 306) and can accordingly contribute to improved biodegradability of the lubricant composition, making it particularly suitable for applications as gear, rolling bearing, and sliding bearing oil in marine and inland waters, as well as in machinery and machine components on land that may come into contact with water and / or aqueous media.

[0036] The amount of base oil or base oil mixture in the lubricant composition is generally determined by the amounts of the other components contained in the composition; that is, the lubricant composition is made up to 100 wt.% with the base oil. Preferably, the total amount of base oil or base oil mixture is at least 20 wt.%, 30 wt.%, 40 wt.%, 50 wt.%, or 60 wt.%.

[0037] Furthermore, the base oil or base oil mixture used according to the invention preferably has a viscosity of at least 5 mm² / s, more preferably from 5 mm² / s to 20000 mm² / s, particularly preferably from 5 mm² / s to 10000 mm² / s, and most preferably from 5 mm² / s to 1700 mm² / s, in each case measured according to ASTM D 7042 at 40 °C.

[0038] The lubricant composition according to the invention also contains, as a further component B), at least one additive that improves a desired property of the lubricant. Commonly used additives known in the prior art include, but are not limited to, antioxidants, anti-wear additives, high-pressure additives, friction reducers, corrosion inhibitors, non-ferrous metal deactivators, ion complexing agents, solid lubricants, dispersants, pour point and viscosity improvers, UV stabilizers, emulsifiers, color indicators, and defoamers.

[0039] In a preferred embodiment of the present invention, the lubricant composition therefore contains at least one additive selected from antioxidants, anti-wear additives, high-pressure additives, friction reducers, corrosion inhibitors, non-ferrous metal deactivators, ion complexing agents, solid lubricants, dispersants, pour point and viscosity improvers, UV stabilizers, emulsifiers, color indicators, and defoamers. Particularly preferably, the lubricant composition contains a mixture of two or more additives selected from antioxidants, anti-wear additives, high-pressure additives, friction reducers, corrosion inhibitors, non-ferrous metal deactivators, ion complexing agents, solid lubricants, dispersants, pour point and viscosity improvers, UV stabilizers, emulsifiers, color indicators, and defoamers.

[0040] By selectively adding one or more additives, it is possible to improve certain properties of the lubricant and / or to impart certain properties to the lubricant.

[0041] The addition of antioxidants can further improve the oxidation stability of the lubricant composition and thus increase the (thermal) stability.

[0042] The antioxidants are preferably selected from the following compounds, without being limited thereto: amine compounds (aminic antioxidants), in particular linear or branched aliphatic amine compounds and aromatic amine compounds and their salts, wherein the aliphatic and aromatic amine compounds may be substituted with one or more residues selected from linear and / or branched alkyl and aryl residues; phenolic compounds (phenolic antioxidants); propionates; phosphites; sulfur-containing compounds, in particular sulfur-containing phenolic compounds and sulfur-containing carboxylic acids, phosphorus thionates, thiocarbamates, thiophosphates, and thiopropionates; and mixtures of these compounds.

[0043] Particularly preferred antioxidants are selected from aromatic diamines and secondary aromatic amines, phenolic resins, thiophenolic resins, phosphites, zinc thiocarbamate, zinc thiophosphate, butylated hydroxytoluene, butylated hydroxyanisole, phenyl-alpha-naphthylamines, phenyl-beta-naphthylamines, diphenylamine and diphenylamine derivatives, in particular octylated diphenylamines, butylated diphenylamines and styrolated diphenylamines, quinoline and quinoline derivatives, naphthylamine and naphthylamine derivatives, di-alpha-tocopherol, di-tert-butylphenylpropanoic acid and their esters, as well as mixtures thereof.

[0044] Examples of particularly suitable antioxidants according to the invention are benzenamine, N-phenyl, reaction products with 2,4,4-trimethylpentene, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, bis(4-(1,1,3,3-tetramethylbutyl)phenyl)amine, N-[(1,1,3,3-tetramethylbutyl)phenyl]naphthalene-1-amine, isomer mixtures of 90% to 97.5% C7 to C9 alkyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 2.5% to 10% methyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], without being limited thereto.

[0045] Suitable antioxidants are commercially available.

[0046] According to a particularly preferred embodiment of the lubricant composition according to the invention, especially when the lubricant composition is used as a gear, rolling bearing and sliding bearing oil for general industry, the antioxidant is selected from phenolic antioxidants, amine antioxidants, preferably linear or branched aliphatic amine compounds and aromatic amine compounds as well as their salts, wherein the aliphatic and aromatic compounds may be substituted with one or more residues selected from linear and / or branched alkyl and aryl residues, propionates and thiopropionates, wherein amine antioxidants are particularly preferred, especially when the lubricant composition is used as a gear, sliding bearing and rolling bearing oil in the food processing industry for occasional, unintentional food contact.

[0047] According to another particularly preferred embodiment of the present invention, the antioxidant is selected from phenolic antioxidants, amine antioxidants, preferably linear or branched aliphatic amine compounds and aromatic amine compounds and their salts, wherein the aliphatic and aromatic compounds may be substituted with one or more residues selected from linear and / or branched alkyl and aryl residues, phosphites, phosphorus thionates and thiocarbamates, particularly when the lubricant composition is used as gear, sliding bearing and rolling bearing oil in marine and inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media, wherein amine antioxidants are particularly preferred.According to the invention, a single compound or a combination of two or more compounds can be used as an antioxidant.

[0048] Furthermore, the lubricant composition according to the invention can contain one or more corrosion inhibitors. The addition of corrosion inhibitors can impart a corrosion- and rust-inhibiting effect to the lubricant composition.

[0049] Suitable corrosion inhibitors are, without limitation, preferably selected from the group of acid salts, in particular carboxylic acid metal salts, sulfonic acid metal salts, naphthalenesulfonic acid metal salts, benzosulfonic acid metal salts, benzoic acid metal salts, naphthoic acid metal salts, succinic acid metal salts, salicylic acid metal salts and phosphoric acid metal salts, as well as their derivatives, including linear and branched aliphatic and aromatic derivatives of the acids / acid salts, which may also be substituted with one or more residues selected from linear and / or branched alkyl and aryl residues, wherein sodium (Na), calcium (Ca), potassium (K) and magnesium (Mg) salts are particularly preferred;Amine, imine and imide compounds and their metal salts, in particular linear and branched aliphatic amine, imine and imide compounds and aromatic amine, imine and imide compounds and their metal salts, wherein the aliphatic and aromatic amine, imine and imide compounds may be substituted with one or more residues selected from linear and / or branched alkyl and aryl residues, wherein Na, Ca, K and Mg salts are particularly preferred; and partially neutralized or non-neutralized dicarboxylic acid derivatives, such as succinic acid half-esters.

[0050] Suitable corrosion inhibitors are commercially available.

[0051] When the lubricant composition is used as gear, plain bearing and rolling bearing oil in the food processing industry for occasional, unintentional food contact, the use of N-methylglycine or its derivatives (e.g. sarcosine) as a corrosion inhibitor is particularly preferred.

[0052] According to a particularly preferred embodiment of the lubricant composition according to the invention, especially when the lubricant composition is used as a gear, rolling bearing and sliding bearing oil for general industry as well as in the food processing industry for occasional, unintentional food contact, the corrosion inhibitor is selected from the group consisting of carboxylic acid metal salts, sulfonic acid metal salts, benzosulfonic acid metal salts, naphthalenesulfonic acid metal salts, benzoic acid metal salts and naphthoic acid metal salts and naphthenic acid metal salts, as well as their derivatives, including linear and branched aliphatic and aromatic derivatives of the acid salts, which may also be substituted with one or more residues selected from linear and / or branched alkyl and aryl residues, wherein Na, Ca, K and Mg salts are particularly preferred; and partially neutralized ornon-neutralized dicarboxylic acid derivatives, such as succinic acid half-esters.

[0053] According to another particularly preferred embodiment of the present invention, the corrosion inhibitor is selected from neutralized or neutral acid salts, preferably from neutral carboxylic acid, sulfonic acid, naphthalenesulfonic acid, benzosulfonic acid, benzoic acid, naphthoic acid, naphthenic acid and phosphoric acid metal salts and their derivatives, including linear and branched aliphatic and aromatic derivatives of the acid salts, which may also be substituted with one or more residues selected from linear and / or branched alkyl and aryl residues, and preferably the Na, Ca, K and Mg salts, wherein neutralized orNeutral sulfonic acid, naphthalenesulfonic acid, and benzosulfonic acid metal salts are particularly preferred, and especially the calcium salts, with neutral calcium sulfonates being most preferred, particularly when the lubricant composition is used as gear, rolling bearing, and sliding bearing oil in marine and inland waters, as well as in machinery and machine components on land that may come into contact with water and / or aqueous media. Neutral alkylnaphthalenesulfonic acid calcium salts represent an example of a particularly suitable corrosion inhibitor of this embodiment.

[0054] The corrosion inhibitors can be used individually or in a combination of two or more.

[0055] For the purposes of the present invention, "neutral" or "neutralized" acid salts or metal salts are understood to be acid salts or metal salts which have an acid number (TAN) of 30 mg KOH / g or less.

[0056] Furthermore, the lubricant composition according to the invention can contain one or more non-ferrous metal deactivators and / or ion complexing agents.

[0057] By adding non-ferrous metal deactivators and / or ion complexing agents, non-ferrous metals, such as cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), tin (Sn), and zinc (Zn), which are among the so-called non-ferrous metals, as well as their alloys, can be protected from corrosion by activated sulfur.

[0058] Suitable non-ferrous metal deactivators and ion complexing agents are preferably selected from triazole compounds, in particular tolyltriazole, benzotriazole and their derivatives, imidazoline compounds, diazoles, and mercaptothiadiazoles. Particularly preferred non-ferrous metal deactivators or ion complexing agents are triazole compounds, salicylates, and mercaptothiadiazoles, as well as their derivatives, with triazole compounds and derivatives thereof, in particular benzotriazole and derivatives thereof, being especially preferred both when the lubricant composition is used as gear, rolling bearing, and sliding bearing oil for general industry, as well as in marine and inland water applications, and in machinery and machine elements on land that may come into contact with water and / or aqueous media. According to the invention, the non-ferrous metal deactivators or ion complexing agents can be used individually or in a combination of two or more of them.

[0059] Examples of particularly preferred non-ferrous metal deactivators or ion complexing agents are benzotriazole and tolyltriazole and derivatives thereof, N,N-bis(2-ethylhexyl)-ar-methyl-1H-benzotriazol-1-methanamine, and a reaction mass of N,N-bis(2-ethylhexyl)-6-methyl-1H-benzotriazol-1-methanamine, N,N-bis(2-ethylhexyl)-4-methyl-2H-benzotriazol-2-methanamine, N,N-bis(2-ethylhexyl)-5-methyl-2H-benzotriazol-2-methanamine, N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazol-1-methylamine and N,N-bis(2-ethylhexyl)-5-methyl-1H-benzotriazol-1-methylamine, without being limited thereto.

[0060] Suitable non-ferrous metal deactivators or ion complexing agents are commercially available.

[0061] The lubricant composition according to the invention may also contain one or more anti-wear agents, friction reducers and / or high-pressure additives. Suitable anti-wear agents, friction reducers, and high-pressure additives are preferably selected from amines, amine phosphates, branched and / or linear alkylated phosphates, phosphites, thiophosphates, and phosphothinates, aryl phosphates, aryl thiophosphates, alkylated polysulfides, sulfurized amine compounds, sulfurized fatty acid methyl esters, naphthenic acids, nanoparticles selected from Al₂O₃, SiO₂, TiO₂, ZrO₂, WO₃, Ta₂O₅, V₂O₅, CeO₂, aluminum titanate, BN, MoSi₂, SiC, Si₃N₄, TiC, TiN, ZrB₂, clay minerals and their mixtures, sulfonic acid salts, and thermally stable carbonates and sulfates, as well as mixtures of two or more thereof, without to be limited to this.Suitable commercially available additives include, for example, the following products: IRGALUBE®< TPPT, IRGALUBE®< 232, IRGALUBE®< 349, IRGALUBE®< 353, IRGALUBE®< 211 and ADDITIN®< RC3760 Liq 3960, FIRC-SHUN®< FG 1505 and FG 1506, NA-LUBE®< KR-015FG, LUBEBOND®< , FLUORO®< FG, SYNALOX®< 40-D, ACHESON®< FGA 1820 and ACHESON®< FGA 1810.

[0062] The lubricant composition according to the invention may also contain one or more viscosity improvers. Suitable viscosity improvers are preferably selected from linear and branched alkylated, acrylated, and aliphatic polymers and copolymers, as well as polymerized fatty acid esters, and mixtures of two or more thereof, without being limited thereto. Examples of suitable viscosity improvers are polymethacrylate, ethylene-propylene copolymer, polyisobutylene, polyalkylstyrene, and hydrogenated styrene-isoprene copolymer. Suitable viscosity improvers are commercially available.

[0063] The lubricant composition according to the invention may also contain one or more UV stabilizers. Suitable UV stabilizers are preferably selected from nitrogen heterocycles and substituted nitrogen heterocycles, as well as mixtures of two or more thereof, without being limited thereto. Suitable UV stabilizers are commercially available.

[0064] The lubricant composition according to the invention may also contain one or more solid lubricants. Suitable solid lubricants are preferably selected from PTFE, boron nitride, zinc oxide, magnesium oxide, pyrophosphates, thiosulfates, magnesium carbonate, calcium carbonate, calcium stearate, zinc sulfide, molybdenum sulfide, tungsten sulfide, tin sulfide, graphite, graphene, nanotubes, SiO₂ modifications, and mixtures of two or more thereof, without being limited thereto. Suitable solid lubricants are commercially available.

[0065] The lubricant composition according to the invention may also contain one or more emulsifiers. Suitable emulsifiers are preferably selected from branched and / or linear ethoxylated and / or propoxylated alcohols and their salts, in particular alcohols with chain lengths of 14-18 carbon atoms, ethoxylated and / or propoxylated alkyl ethers, fatty acid esters, and ionic surfactants such as sodium salts of alkylsulfonic acids, as well as mixtures of two or more thereof, without being limited thereto. Suitable emulsifiers are commercially available.

[0066] The lubricant composition according to the invention may also contain one or more defoamers to prevent the formation of solid foams. Suitable defoamers are preferably selected from ethoxylated and / or propoxylated alcohols with chain lengths of 10-18 carbon atoms, mono- and diglycerides of edible fats, acrylates, propoxylated and / or ethoxylated alkyl ethers, polyols including diols, and polysiloxanes, such as silicone oils or polydimethylsiloxanes, as well as mixtures of two or more thereof, without being limited thereto.According to the invention, particularly preferred defoamers are ethoxylated and / or propoxylated alcohols with chain lengths of 10-18 carbon atoms, polyols, acrylates, and polysiloxanes, with polysiloxanes being especially preferred. These defoamers are particularly preferred both when the lubricant composition is used as a gear, rolling bearing, and sliding bearing oil in marine and inland waters, as well as in machines and machine components on land that may come into contact with water and / or aqueous media, and also when the lubricant composition is used as a gear, rolling bearing, and sliding bearing oil for general industry and in the food processing industry for occasional, unintentional food contact. Suitable defoamers are commercially available.

[0067] The lubricant composition according to the invention may also contain one or more color indicators. A suitable color indicator is, for example, 2,5-thiophenediylbis(5-ter-butyl-1,3-benzoxazole), but this is not the only possible combination. Suitable color indicators are commercially available.

[0068] All additives can each be present as a single compound or in a combination of two or more in the lubricating grease composition according to the invention.

[0069] The total amount of all additives in the lubricant composition is preferably 0.01 wt.% or more, particularly preferably 0.025 wt.% or more, for example 0.5 wt.% or more, and 10 wt.% or less, particularly preferably 7.5 wt.% or less, for example 6 wt.% or less, or 5 wt.% or less, based on the total lubricant composition.

[0070] For example, in embodiments of the invention that are particularly suitable for use as gear, rolling bearing and sliding bearing oil for general industry, including in the food processing industry for occasional, unintentional food contact, it is particularly preferred if the total amount of all additives is 0.01-7.5 wt.%, most preferably 0.01-6.0 wt.%, based on the total weight of the lubricant composition.

[0071] For example, in embodiments of the invention that are particularly suitable for use as gear, rolling bearing and sliding bearing oil in marine and inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media, it is particularly preferred if the total amount of all additives is 0.5-7.0 wt.%, most preferably 0.5-5.0 wt.%, based on the total weight of the lubricant composition.

[0072] Since the additives serve to improve certain properties of the lubricant and / or to impart certain properties to it, they can be added to the lubricant as a single substance or as a mixture of two or more additives, depending on the need or requirement for the lubricant, whereby the quantity of the individual additives in an additive mixture is not limited as long as the total quantity of all additives defined above, in relation to the entire lubricant composition, is not exceeded.

[0073] In a further preferred embodiment of the invention, which is particularly suitable for use as a gear, rolling bearing and sliding bearing oil for general industry including the food processing industry, the lubricant composition contains an additive mixture of two or more additives, comprising one or more antioxidants, one or more anti-wear and / or high-pressure additives, one or more defoamers, optionally one or more non-ferrous metal deactivators, optionally one or more corrosion inhibitors, and optionally a color indicator.

[0074] According to this embodiment, the base oil is preferably selected from polyalphaolefins (PAOs), metallocene polyalphaolefins (mPAOs), white oils, mineral oils, and mixtures of two or more of these.

[0075] Lubricants of this embodiment exhibit high compatibility with elastomers such as FKM, NBR, HNBR, ACM / AEM, and polyurethanes, which are commonly used as sealing materials. At the same time, lubricants of this embodiment display good tribological properties, resulting in improved sliding behavior, a reduction in the stick-slip effect, particularly in frictional contact under high load and low bearing speeds, and a positive influence on micropitting resistance. Therefore, they are particularly suitable for use as gear, rolling bearing, and plain bearing oils in general industry.

[0076] According to the present invention, which is particularly suitable for use as a gear, rolling bearing and sliding bearing oil in the marine sector and in inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media, the lubricant composition contains as an additional component D) an ester compound, wherein mixtures of two or more different ester compounds are also included according to the invention.

[0077] The ester compound D) is selected from natural glyceride esters, in particular from the group consisting of sunflower oil, rapeseed oil or rapeseed oil, linseed oil, maize oil, safflower oil, soybean oil, linseed oil, peanut oil, lesqueralle oil, palm oil, olive oil, each of which may be in monomeric, oligomeric and / or polymerized form, as well as mixtures of the aforementioned oils; and synthetic esters from the group consisting of polyol esters, polyol complex esters, complex esters of dimer acids, dimeric acid esters, aliphatic carboxylic acid and dicarboxylic acid esters, phosphate esters and trimellite and pyromellitic acid esters;and combinations thereof, wherein polyol esters and polyol complex esters are particularly preferred, and in particular such polyol esters obtained by reacting polyhydric alcohols (i.e., alcohols with more than one hydroxyl group) with monocarboxylic acids (i.e., monohydric carboxylic acids), and in particular such polyol complex esters obtained by reacting polyhydric alcohols with monocarboxylic and dicarboxylic acids (i.e., dihydric carboxylic acids) in any mixture, as well as combinations thereof.

[0078] In this embodiment of the invention, it is preferred that the ester compounds D) are biodegradable according to OECD standard 301 A - F or OECD 306 in order to achieve improved biodegradability and environmental compatibility of the lubricant composition according to the invention.

[0079] Furthermore, it is preferred that the at least one ester compound has a kinematic viscosity of at least 130 mm² / s at 40°C. Particularly preferred is a kinematic viscosity of the at least one ester compound in the range of 130–1500 mm² / s at 40°C, and more preferably in the range of 130–1300 mm² / s at 40°C, in each case measured according to ASTM D 7042.

[0080] According to the present invention, the ester compounds are contained in the lubricant composition in an amount of 10-85 wt.%, based on the total weight of the lubricant composition.

[0081] According to a further preferred embodiment of the present invention, the lubricant composition of the present invention comprises: A) a base oil; B) 0.5-7 wt.% of the at least one additive, based on the total weight of the lubricant composition; C) 0.1-5 wt.% of the organic compound, based on the total weight of the lubricant composition; and D) 10-85 wt.% of the ester compound, based on the total weight of the lubricant composition wherein the included components supplement each other to a total of 100 wt.% and components A), B), C) and D) are defined as above.

[0082] A lubricant of this composition exhibits high compatibility with sealing materials, especially elastomers, good sliding properties and is also readily biodegradable, and is therefore particularly suitable for use as gear oil, rolling bearing oil and sliding bearing oil in marine and inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media.

[0083] The present invention therefore relates in a further aspect to a lubricant composition, in particular for use as gear oil, rolling bearing oil and sliding bearing oil in the marine sector and in inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media, comprising as components: A) a base oil; B) 0.5-7 wt.% of at least one additive; C) 0.1-5 wt.% of an organic compound comprising both a polar and a nonpolar part; and D) 10-85 wt.% of an ester compound, wherein the specified amounts each refer to the total weight of the lubricant composition and add up to a total of 100 wt.%, and wherein the organic compound has a relative permittivity ε r in the range of 1.5 to 10, preferably from 1.7 to 8, particularly preferably from 2 to 7, and most preferably from 2.3 to 5, and wherein a quotient ∫ S 1 / ∫-S 2 of the organic compound is in the range of 1 to 25, preferably from 1.3 to 22, particularly preferably from 1.7 to 17, and most preferably from 2 to 14, wherein "∫ S 1" denotes the sum of the area(s) of the IR absorption band(s) in the wavenumber range 3100-2750 cm⁻¹< in an ATR spectrum of the organic compound, and "∫ S 2" denotes the sum of the area(s) of the IR absorption band(s) in the Wavenumber range 1800-1650 cm -1< in an ATR spectrum of the organic compound.

[0084] Components A), B), C) and D) are preferably defined as above.

[0085] Particularly preferably according to this embodiment, the ester compound D) is selected from neopentyl glycol esters, trimethylolpropane esters, and pentaerythritol esters, which are esterified in particular with saturated and / or mono- or polyunsaturated, linear and / or branched monocarboxylic acids of chain length C4-C36, preferably C10-36, particularly preferably C14-C36, and most preferably C18-C36; and neopentyl glycol complex esters, trimethylolpropane complex esters, and pentaerythritol complex esters, which are in particular fully or partially esterified with saturated and / or mono- or polyunsaturated, linear and / or branched monocarboxylic acids of chain length C4-C36, preferably C10-C36, particularly preferably C14-C36, and most preferably C18-C36, and with saturated and / or mono- or polyunsaturated, linear and / or branched dicarboxylic acids of chain length C4-C36, preferably C4-C18, particularly preferably C4-C12, in any mixture, there are still free, unesterified hydroxyl groups present); as well as combinations thereof.

[0086] These ester compounds are particularly preferred with regard to the biocompatibility or biodegradability of the lubricant composition.

[0087] Examples of particularly preferred ester compounds are pentaerythritol tetraisostearate, pentaerythritol isostearate sebacate complex ester, trimethylolpropane triisostearate, trimethylolpropane trioleate, trimethylolpropane tricaprylate, trimethylolpropane isostearate stearate sebacate complex ester, neopentyl glycol diisostearate, but are not limited to these.

[0088] Furthermore, according to this embodiment, it is particularly preferred that the base oil is selected from oil-soluble polyglycols, polyalphaolefins (PAOs), metallocene polyalphaolefins (mPAOs), white oils, farnesene-based oils, estolides, and mixtures of two or more thereof, with oil-soluble polyglycols, polyalphaolefins (PAOs), and metallocene polyalphaolefins (mPAOs) being especially preferred. These base oils have particularly advantageous properties with regard to their biodegradability (i.e., biodegradable, for example, according to OECD Test Guideline 301 AF or OECD 306) and can accordingly contribute to improved biodegradability of the lubricant composition.

[0089] By carefully selecting additives that are optimally matched to the tribosystem of elastomer material, lubricant, and metal, a further improvement in the elastomer compatibility of the lubricant composition can be achieved. Accordingly, in this embodiment of the invention, it is preferred that the lubricant composition contains an additive mixture comprising one or more antioxidants, non-ferrous metal deactivators, and corrosion inhibitors, and optionally one or more defoamers and anti-wear and / or high-pressure additives.

[0090] It is therefore particularly preferred according to this embodiment of the invention that the at least one additive B) is an additive mixture containing one or more antioxidants, non-ferrous metal deactivators, and corrosion inhibitors, and optionally one or more defoamers, anti-wear agents, and / or high-pressure additives. The following have proven particularly advantageous in this respect: Antioxidants selected from phenolic antioxidants, amine antioxidants, preferably linear or branched aliphatic amine compounds and aromatic amine compounds and their salts, wherein the aliphatic and aromatic compounds may be substituted with one or more residues selected from linear and / or branched alkyl and aryl residues, phosphites, phosphorus thionates and thiocarbamates, wherein amine antioxidants are particularly preferred; non-ferrous metal deactivators selected from triazole compounds, salicylates and mercaptothiadiazoles, and their derivatives, wherein triazole compounds, in particular benzotriazole compounds, and derivatives thereof are particularly preferred;Corrosion inhibitors selected from neutralized or neutral carboxylic acid, sulfonic acid, naphthalenesulfonic acid, benzosulfonic acid, naphthoic acid, naphthenic acid, and phosphoric acid metal salts, and their derivatives, preferably sodium, calcium, potassium, and magnesium salts, wherein neutralized or neutral sulfonic acid, naphthalenesulfonic acid, and benzosulfonic acid metal salts are particularly preferred, especially calcium salts, and wherein neutral calcium sulfonates, such as neutral alkylnaphthalenesulfonic acid calcium salts, are especially preferred; defoamers selected from ethoxylated and / or propoxylated alcohols with chain lengths of 10-18 carbon atoms, polyols including diols, acrylates, and polysiloxanes, wherein polysiloxanes are particularly preferred;Anti-wear and / or high-pressure additives selected from amines, amine phosphates, branched and / or linear alkylated phosphates, phosphites, thiophosphates and phosphothinates, aryl phosphates, alkylated polysulfides, sulfurized amine compounds, sulfurized fatty acid methyl esters, naphthenic acids, nanoparticles selected from Al₂O₃, SiO₂, TiO₂, ZrO₂, WO₃, Ta₂O₅, V₂O₅, CeO₂, aluminum titanate, BN, MoSi₂, SiC, Si₃N₄, TiC, TiN, ZrB₂, clay minerals and their mixtures, sulfonic acid salts, and thermally stable carbonates and sulfates.

[0091] Such an additive mixture is particularly suitable for lubricant compositions for use as gear, rolling bearing or sliding bearing oil in marine and inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media.

[0092] Furthermore, a particularly preferred embodiment of the invention therefore comprises an additive mixture comprising: one or more antioxidants selected from amine antioxidants, phenolic antioxidants, phosphites, phosphorus thionates, and thiocarbamates; one or more non-ferrous metal deactivators selected from triazole compounds, salicylates, and mercaptothiadiazoles, and their derivatives; one or more corrosion inhibitors selected from neutralized / neutral carboxylic acid, sulfonic acid, naphthalenesulfonic acid, benzosulfonic acid, benzoic acid, naphthoic acid, naphthenic acid, and phosphoric acid metal salts, and their derivatives, in particular sodium, calcium, potassium, and magnesium salts; optionally, one or more defoamers selected from ethoxylated and / or propoxylated alcohols with chain lengths of 10–18 carbon atoms, polyols, acrylates, and polysiloxanes;and optionally one or more anti-wear and / or high-pressure additives selected from amines, amine phosphates, branched and / or linear alkylated phosphates, phosphites, thiophosphates and phosphothinates, aryl phosphates, alkylated polysulfides, sulfurized amine compounds, sulfurized fatty acid methyl esters, naphthenic acids, nanoparticles selected from Al₂O₃, SiO₂, TiO₂, ZrO₂, WO₃, Ta₂O₅, V₂O₅, CeO₂, aluminum titanate, BN, MoSi₂, SiC, Si₃N₄, TiC, TiN, ZrB₂, clay minerals and their mixtures, sulfonic acid salts, and thermally stable carbonates and sulfates.

[0093] A lubricant composition that is particularly suitable for use as a gear, rolling bearing or sliding bearing oil in marine and inland waters as well as in machines and machine elements on land that may come into contact with water and / or aqueous media therefore contains, according to a particularly preferred embodiment of the present invention: A) a base oil; B) 0.5-7 wt.% of an additive mixture, based on the total weight of the lubricant composition, wherein the additive mixture comprises: one or more antioxidants selected from amine antioxidants, phenolic antioxidants, phosphites, phosphorus thionates and thiocarbamates; one or more non-ferrous metal deactivators selected from triazole compounds, salicylates and mercaptothiadiazoles, and their derivatives; one or more corrosion inhibitors selected from neutralized / neutral carboxylic acid, sulfonic acid, naphthalenesulfonic acid, benzosulfonic acid, benzoic acid, naphthoic acid, naphthenic acid and phosphoric acid metal salts, and their derivatives; optionally one or more defoamers selected from ethoxylated and / or propoxylated alcohols with chain lengths of 10-18 carbon atoms, polyols, acrylates and polysiloxanes;and optionally one or more anti-wear and / or high-pressure additives selected from amines, amine phosphates, branched and / or linear alkylated phosphates, phosphites, thiophosphates, and phosphothinates, aryl phosphates, alkylated polysulfides, sulphured amine compounds, sulphured fatty acid methyl esters, naphthenic acids, nanoparticles selected from Al₂O₃, SiO₂, TiO₂, ZrO₂, WO₃, Ta₂O₅, V₂O₅, CeO₂, aluminum titanate, BN, MoSi₂, SiC, Si₃N₄, TiC, TiN, ZrB₂, clay minerals and their mixtures, sulfonic acid salts, and thermally stable carbonates and sulfates; C) 0.1-5 wt.% of the organic compound, based on the total weight of the lubricant composition; and D) 10-85 wt.% of the ester compound, based on the total weight of the lubricant composition; wherein the ester compound is selected from neopentyl glycol esters, trimethylolpropane esters, and pentaerythritol esters, which are particularly esterified with saturated and / or mono- or polyunsaturated, linear and / or branched monocarboxylic acids of chain length C4-C36, preferably C10-36, particularly preferably C14-C36, and most preferably C18-C36; and neopentyl glycol complex esters, trimethylolpropane complex esters, and pentaerythritol complex esters, which are in particular fully or partially esterified with saturated and / or mono- or polyunsaturated, linear and / or branched monocarboxylic acids of chain length C4-C36, preferably C10-C36, particularly preferably C14-C36, and most preferably C18-C36, and with saturated and / or mono- or polyunsaturated, linear and / or branched dicarboxylic acids of chain length C4-C36, preferably C4-C18, particularly preferably C4-C12, in any mixture; as well as combinations thereof;wherein the base oil is selected from oil-soluble polyglycols, polyalphaolefins (PAOs), metallocene polyalphaolefins (mPAOs), white oils, farnesene-based oils, estolides, and mixtures of two or more thereof, and wherein the components contained therein are complementary to a total of 100% by weight and component C) is defined as above.

[0094] It is particularly preferred that the additive mixture is largely neutral or has the lowest possible total acid number (TAN), as this is particularly advantageous with regard to the elastomer compatibility of the lubricant compositions.

[0095] According to this embodiment of the invention, it is particularly preferred that the lubricant composition contains: A) a base oil selected from oil-soluble polyglycols, polyalphaolefins (PAOs) and metallocene polyalphaolefins (mPAOs), and mixtures of two or more thereof; B) 0.5-5 wt.% of an additive mixture comprising one or more amine antioxidants, one or more neutralized / neutral sulfonic acid, naphthalenesulfonic acid and / or benzosulfonic acid metal salts, one or more triazole compounds, in particular benzotriazole compounds, and / or derivatives thereof, and one or more polysiloxanes; C) 0.1-5 wt.% of the organic compound; and D) 10-85 wt.% pentaerythritol esters; wherein the specified quantities each refer to the total weight of the lubricant composition and the components contained therein supplement each other to a total of 100 wt.%, and the organic compound C) is defined above.

[0096] A lubricant of this composition exhibits high compatibility with sealing materials, especially elastomers, as well as good sliding and lubricating properties. Furthermore, a lubricant of this composition has good biocompatibility, i.e., good biodegradability according to OECD standards 301 A - F or OECD 306, and low aquatoxicity (e.g., according to OECD standards 201, 202, 203, or 236), and is therefore particularly suitable for use as a gear oil, rolling bearing oil, or sliding bearing oil in marine and inland waters, as well as in machinery and machine components on land that may come into contact with water and / or aqueous media.

[0097] The present invention therefore also relates to a lubricant composition for use as gear, rolling bearing and sliding bearing oil in marine and inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media, comprising as components: A) a base oil selected from oil-soluble polyglycols, polyalphaolefins (PAOs) and metallocene polyalphaolefins (mPAOs), and mixtures of two or more thereof; B) 0.5-5 wt.% of an additive mixture comprising one or more amine antioxidants, one or more neutralized / neutral sulfonic acid, naphthalenesulfonic acid and / or benzosulfonic acid metal salts, one or more triazole compounds and / or triazole derivatives, and one or more polysiloxanes; C) 0.1-5 wt.% of an organic compound comprising both a polar and a nonpolar part; and D) 10-85 wt.% pentaerythritol esters. wherein the specified quantities each refer to the total weight of the lubricant composition and the components supplement each other to a total of 100 wt.%, and wherein the organic compound has a relative permittivity ε r in the range of 1.5 to 10, preferably from 1.7 to 8, particularly preferably from 2 to 7, and most preferably from 2.3 to 5, and wherein a quotient ∫ S 1 / ∫-S 2 of the organic compound is in the range of 1 to 25, preferably from 1.3 to 22, particularly preferably from 1.7 to 17, and most preferably from 2 to 14, wherein "∫ S 1" denotes the sum of the area(s) of the IR absorption band(s) in the wavenumber range 3100-2750 cm⁻¹< in an ATR spectrum of the organic compound, and "∫ S 2" denotes the sum of the area(s) of the IR absorption band(s) in the wavenumber range 1800-1650 cm -1< in an ATR spectrum of the organic compound.

[0098] According to one embodiment, the lubricant composition according to the invention is ideally suited for use as gear oils, rolling bearing oils and sliding bearing oils for general industry, including as gear oil, rolling bearing oil and sliding bearing oil for occasional, unintentional contact with food.

[0099] Generally, areas of application, which include use as gear oils, rolling bearing oils and plain bearing oils for general industry, encompass the lubrication of gearboxes, in particular spur gear, bevel gear, planetary gear, worm gear, hypoid and cycloidal gears, hydraulics, linear guides, pneumatic components, fittings, bearings, in particular plain and rolling bearings, chains, ropes, springs, screws and compressors, and in particular also of machine components and in equipment that come into occasional, unintentional contact with foodstuffs, without being limited thereto.

[0100] Chains consist of identical, interconnected links. They serve to transmit power and are used as drive chains, for example, on bicycles, as timing chains in automotive engines, as load chains in lock gates, or as transport chains in conveyor systems. Ropes can be divided into running ropes, such as those found in cranes, winches, and elevators; static ropes, such as guy ropes; and support ropes and slings. Screws are fasteners designed to be installed and removed with minimal effort and without damaging the materials used. Springs include leaf springs, disc springs, ring springs, helical disc springs, and torsion springs. Valves are used to regulate the flow of solids, liquids, and gases. They can also perform the function of positioning, i.e., mixing and regulating one or more volumetric flow rates.In addition to the typical applications as taps or mixer taps, all types of valves are also considered fittings.

[0101] Pneumatic components are pneumatic valves and cylinders that generate linear movements for moving, lifting, or returning workpieces and tools by converting pneumatic energy into mechanical energy.

[0102] In hydraulic systems, force and torque are transmitted via pressure and flow rate. Examples include axial piston machines, external gear machines, and radial piston motors.

[0103] A further object of the present invention is therefore the use of the lubricant compositions according to the invention as gear oil, rolling bearing oil and plain bearing oil for general industry, in particular for the lubrication of gears such as spur gear, bevel gear, planetary gear, worm gear, hypoid and cycloidal gears, hydraulics, linear guides, pneumatic components, fittings, bearings such as plain and rolling bearings, chains, ropes, springs, screws and compressors, and in particular of machine components and in systems that come into occasional, unintentional contact with foodstuffs, wherein the lubricant composition is defined as above.

[0104] According to a further embodiment, the lubricant composition according to the invention is also ideally suited for use as gear oil, rolling bearing oil and sliding bearing oil in the marine sector and in inland waters, as well as in machines and machine elements on land that may come into contact with water and / or aqueous media.

[0105] Application areas in the marine sector and inland waters include, but are not limited to, the lubrication of gears, hydraulics, bearings such as plain, rolling or stern tube bearings, propeller rudders, propeller shafts, pneumatic components, linear guides, chains and ropes in machines, machine components and systems that come into contact with salt water in the marine sector, for example offshore installations, or with water and / or aqueous media in inland waters.

[0106] In marine applications, gearboxes are used, for example, in thrusters and azipods. This application serves to transmit and convert power between the drive and the propeller. Here, both water ingress and lubricant leakage into the marine environment are to be expected.

[0107] Another application in the marine sector is jack-up systems, which lift platforms, installation vessels for wind turbines, or drilling rigs. This movement is achieved through open gearboxes.

[0108] Hydraulic systems in the marine sector are used to drive adjustable propeller rudders, as well as fin stabilizers and rudder bearings. Linear guides, usually lubricated with the same lubricant, are also used in the latter. Here, too, lubrication takes place below the waterline. Accordingly, water ingress into the machine parts and lubricant leakage into the marine environment are to be expected in this case as well.

[0109] In marine applications, the primary use of plain bearings is for propeller shaft bearings located in the stern tube, the so-called stern tube bearing. The primary function of the propeller shaft is to transmit the propulsion motion through the ship's hull to the propeller. The bearing ensures low-friction movement.

[0110] Furthermore, machines and machine components in offshore wind turbines, oil and gas production platforms, port facilities, shipyards and the like, which come into contact with seawater, water and aqueous media, are lubricated.

[0111] This also includes chains, such as those used in lock gates, ropes like ship hawsers or ropes used in nets, as well as fittings for regulating the flow of solids, liquids, and gases. Screws, springs, and valves in a wide variety of apparatus and machinery also require lubrication.

[0112] A further object of the present invention is therefore the use of the lubricant composition according to the invention as gear oil, rolling bearing oil and sliding bearing oil in the marine sector and in inland waters, in particular for the lubrication of gears, hydraulics, propeller rudders, propeller shafts, linear guides, pneumatic components, fittings, bearings such as sliding, rolling or stern tube bearings, chains, ropes, springs and screws in machines, machine components and systems that come into contact with salt water in the marine sector or with water and / or aqueous media in inland waters, as well as in machines and machine elements on land that can come into contact with water and / or aqueous media, wherein the lubricant composition is defined as above.

[0113] The use of a lubricant composition containing the following is particularly preferred: A) a base oil selected from oil-soluble polyglycols, polyalphaolefins (PAOs) and metallocene polyalphaolefins (mPAOs), and mixtures of two or more thereof; B) 0.5–5 wt.% of an additive mixture comprising one or more amine antioxidants, one or more neutralized / neutral sulfonic acid, naphthalenesulfonic acid and / or benzosulfonic acid metal salts, one or more triazole compounds and / or triazole derivatives, and one or more polysiloxanes; C) 0.1–5 wt.% of the organic compound; and D) 10–85 wt.% pentaerythritol esters; wherein the specified quantities each refer to the total weight of the lubricant composition and the components contained therein supplement each other to a total of 100 wt.%, and wherein the organic compound C) is defined as above, as gear oil, rolling bearing oil and sliding bearing oil in marine and inland waters as well as in machines and machine elements on land that may come into contact with water and / or aqueous media.

[0114] The present invention is described in more detail by the following non-limiting examples. A person skilled in the art can produce further compounds according to the invention without having to perform any inventive steps. Examples General testing methods used

[0115] The properties of the lubricant composition and the components it contains are determined using the following methods, unless known from the manufacturer: Viscosity determination: Viscosity measurements are performed according to ASTM D 7042 using a Stabinger SVM 3000 viscometer (Anton Paar). Acid number determination (TAN, total acid number [mg KOH / g]): To determine the acid number, the sample is dissolved in a solvent mixture and then titrated with an alcoholic potassium hydroxide solution according to ASTM D 664-18E02. The titration is performed potentiometrically using a solvotrode on a Metrohm 905 Titrando titration unit. Molecular weight determination (Mn): The molecular weight is determined by gel permeation chromatography (GPC) against a polystyrene standard according to DIN 55672-1:2016-03 "Gel permeation chromatography (GPC) - Part 1: Tetrahydrofuran (THF) as eluent" using a SECcure GPC system.Determination of the integrals ∫ S 1 and ∫ S 2: ATR infrared spectroscopy measurements on the sliding improvers are carried out in accordance with the standard DIN 51451 (DIN 51451:2020-02) "Testing of petroleum products and related products: Infrared spectrometric analysis - General principles", adapted to ATR measurement using a Bruker Tensor 27 IR spectrometer (software OPUS 7.5) or Bruker Vertex 70 (software OPUS 7.0) from Bruker Optik GmbH.

[0116] The following regions in the ATR spectrum are used to form the integrals ∫ S 1 and ∫ S 2: ∫ S 1 : 3100 − 2750 cm -1 ∫ S 2 : 1800 − 1650 cm -1

[0117] The following procedure is used to form the baseline in both integrals.

[0118] The integral domain is bisected. The respective absolute minima are determined within each of these two subdomains. If there are multiple absolute minimum points in a subdomain, the point furthest from the boundary of the entire integral is used. The baseline is calculated from the two absolute minimum points in the entire integral using a linear equation. The spectrum to be integrated is then adjusted for the baseline. Finally, the baseline-adjusted spectrum is integrated. - Determination of the relative permittivity ε r :

[0119] To determine the relative permittivity εr, the complex fluid impedance is determined using a laboratory measuring instrument of the EPSILON+ system from the manufacturer flucon fluid control GmbH, in accordance with the standard DIN EN 60247 (DIN EN 60247:2005-01) "Insulating fluids - Measurement of permittivity, dielectric loss factor (tan δ) and DC specific resistance". For each lubricant to be tested, a measurement with continuous data acquisition is performed after filling the sample at room temperature (approx. 20 °C), from approx. 18.5 to 21.5 °C (step 1) and back again (step 2). Subsequently, the data obtained at the specified temperature of 20.0 °C from both steps are compared and averaged.

[0120] Overview of the lubrication improvers used in the examples (see Tables 1-a and 1-b): Table 1-a Lubricant improver (L) Trade name CAS number GV1 Ketjenlube ®< 135 191744-19-1 GV2* Perfad™ < 3000 1392101-03-9 GV3* Lubrizol 87725 1654003-52-7 GV4* Herwemag OA 67701-08-0 GV5* Ilco Lube 2316 G 68424-61-3 Polyalphaolefin 6 (PAO 6) (not according to the invention) Durasyn® < 166 68037-01-4 *Reference examples Table 1-b Glide improver ATR spectrum ∫ S 1 ATR spectrum ∫ S 2 ∫ S 1 / ∫ S 2 relative permittivity ε r GV1 180,67 71,87 2,51 3,98 GV2* 226,03 25,71 8,79 4,60 GV3* 234,42 25,57 9,17 2,39 GV4* 203,99 64,91 3,14 2,50 GV5* 190,71 48,81 3,91 4,75 PAO 6 (not according to the invention) 249,84 0,40 626,36 2,12 *Reference examples Production of lubricant compositions:

[0121] The lubricant compositions are produced according to a procedure known to those skilled in the art, whereby the base oils and additives are mixed in a suitable vessel, e.g., a mixing vessel, using a suitable stirrer. Solid additives or components are dissolved by increasing the temperature and stirred in. Production can also be carried out using continuous processes.

[0122] The following lubricant compositions with sliding improvers are produced as described above (see Table 2 - examples according to the invention 1, 3, 6, 8, 10, 12, 14; reference examples 2, 4, 5, 7, 9, 11, 13, 15, 15b). As a control, lubricant compositions without sliding improvers (base formulation) are produced as described above (see Table 2 - comparative examples 1-5). Table 2: Component (wt.%) Example 1 Example 2 Example 3 Base oil 1 mPAO 65 (72,745) PE esters (68.31) mPAO 65 (73,548) Base oil 2 PAO 6 (14.35) PG (27.91) PAO 6 (14,397) Solution intermediary TMP esters (10.00) - TMP esters (10.00) Antioxidant Amine (0.50); ​​Phenolic (0.30) Aminic (0.1) Amine (0.50); ​​Phenolic (0.30) Wear protection agent Amine phosphate (0.50); - Amine phosphate (0.50); Phosphite (0.50); Phosphite (0.50); TPPT (0.50) TPPT (0.50) Non-ferrous metal deactivator Benzotriazole derivative reaction mass (0.095) Benzotriazole derivative reaction mass (0.09) Benzotriazole derivative reaction mass (0.095) Defoamer Silicone oil dissolved in synthetic Silicone-based defoamer (0.1) Silicone oil dissolved in synthetic Hydrocarbon (0.01) Hydrocarbon (0.01) Corrosion protection - Neutral calcium sulfonate (0.49) - Glide improver GV 1 (0.50) GV 3 (3.0) GV 1 (0.25) Component (wt.%) Example 4 Example 5 Example 6 Base oil 1 mPAO 150 (71,095) PE esters (68.31) mPAO 65 (73,045) Base oil 2 PAO 6 (16.00) PG (27.91) PAO 6 (14.35) Solution intermediary TMP esters (10.00) - TMP esters (10.00) Antioxidant Aminic (0.50); Aminic (0.1) Aminic (0.50); Phenolic (0.30) Phenolic (0.30) Wear protection agent Amine phosphate (0.50); - Amine phosphate (0.50); Phosphite (0.50); Phosphite (0.50) TPPT (0.50) Non-ferrous metal deactivator Benzotriazole derivative reaction mass (0.095) Benzotriazole derivative reaction mass (0.09) Benzotriazole derivative reaction mass (0.095) Defoamer Silicone-based defoamer (0.01) Silicone-based defoamer (0.1) Silicone oil dissolved in synthetic hydrocarbon (0.01) Corrosion protection - Neutral calcium sulfonate (0.49) - Glide improver GV 2 (1.00) GV 5 (3.0) GV 1 (0.20) Component (wt.%) Example 7 Example 8 Example 9 Base oil 1 mPAO 150 (71,095) PE esters (68.31) PE esters (68.31) Base oil 2 PAO 6 (16.00) PG (27.91) PG (27.91) Solution intermediary TMP esters (10.00) - - Antioxidant Aminic (0.50); Aminic (0.1) Aminic (0.1) Phenolic (0.30) Wear protection Amine phosphate (0.50); - - medium Phosphite (0.50) Non-ferrous metal deactivator Benzotriazole derivative reaction mass (0.095) Benzotriazole derivative - reaction mass (0.09) Benzotriazole derivative - reaction mass (0.09) Defoamer Silicone-based defoamer (0.01) Silicone-based defoamer (0.1) Silicone-based defoamer (0.1) Corrosion protection - Neutral calcium sulfonate (0.49) Neutral calcium sulfonate (0.49) Glide improver GV 4 (1.00) GV 1 (3.0) GV 4 (3.0) Component (wt.%) Example 10 Example 11 Example 12 Base oil 1 mPAO 150 (71,095) PE esters (68.31) mPAO 65 (73,148) Base oil 2 PAO 6 (16.00) PG (27.91) PAO 6 (14,347) Solution mediator TMP esters (10.00) - TMP esters (10.00) Antioxidant Aminic (0.50); Aminic (0.1) Aminic (0.50); Phenolic (0.30) Phenolic (0.30) Wear protection agent Amine phosphate (0.50); - Amine phosphate (0.50); Phosphite (0.50); Phosphite (0.50) TPPT (0.50) Non-ferrous metal deactivator Benzotriazole derivative reaction mass (0.095) Benzotriazole derivative - reaction mass (0.09) Benzotriazole derivative reaction mass (0.095) Defoamer Silicone-based defoamer (0.01) Silicone-based defoamer (0.1) Silicone oil dissolved in synthetic hydrocarbon (0.01) Corrosion protection - Neutral calcium sulfonate (0.49) - Glide improver GV 1 (1.00) GV 2 (3.0) GV 1 (0.10) Component (wt.%) Example 13 Example 14 Example 15 Base oil 1 mPAO 65 (73,148) PE esters (75,305) mPAO 150 (71,095) Base oil 2 PAO 6 (14,347) PG (20.90) PAO 6 (16.00) Solution mediator TMP esters (10.00) - TMP esters (10.00) Antioxidant Aminic (0.50); Aminic (0.1) Aminic (0.50); Phenolic (0.30) Phenolic (0.30) Wear protection agent Amine phosphate (0.50); - Amine phosphate (0.50); Phosphite (0.50); TPPT (0.50) Phosphite (0.50) Non-ferrous metal deactivator Benzotriazole derivative reaction mass (0.095) Benzotriazole derivative - reaction mass (0.095) Benzotriazole derivative reaction mass (0.095) Defoamer Silicone oil dissolved in synthetic hydrocarbon (0.01) Silicone-based defoamer (0.1) Silicone-based defoamer (0.01) Corrosion protection - Neutral calcium sulfonate (0.5) - Glide improver GV 3 (0.10) GV 1 (3.0) GV 5 (1.00) Component (wt.%) Example 15b Comparison example 1 Comparison example 2 Base oil 1 mPAO 65 (72,745) PE esters (70.43) mPAO 65 (73,148) Base oil 2 PAO 6 (14.60) PG (28.78) PAO 6 (14,347) Solution intermediary TMP esters (10.00) - TMP esters (10.00) Antioxidant Aminic (0.50); Aminic (0.1) Aminic (0.50); Phenolic (0.30) Phenolic (0.30) Wear protection agent Amine phosphate (0.50); - Amine phosphate (0.50); Phosphite (0.50); Phosphite (0.50); TPPT (0.50) TPPT (0.50) Non-ferrous metal deactivator Benzotriazole derivative - reaction mass (0.095) Benzotriazole derivative - reaction mass (0.1) Benzotriazole derivative reaction mass (0.095) Defoamer Silicone-based defoamer (0.01) Silicone-based defoamer (0.1) Silicone oil dissolved in synthetic hydrocarbon (0.01) Corrosion protection - Neutral calcium sulfonate (0.5) - Glide improver GV 2 (0.25) - - Component (wt.%) Comparison example 3 Comparison example 4 Comparison example 5 Base oil 1 PE esters (80,305) mPAO 150 (71,095) PE esters (68.31) Base oil 2 PG (18.90) PAO 6 (16.00) PG (27.91) Solution intermediary - TMP esters (10.00) - Antioxidant Aminic (0.1) Amine (0.50); ​​Phenolic (0.30) Aminic (0.1) Wear protection agent - amine phosphate (0.50); Phosphite (0.50) - Non-ferrous metal deactivator Benzotriazole derivative - reaction mass (0.095) Benzotriazole derivative reaction mass (0.095) Benzotriazole derivative - reaction mass (0.09) Defoamer Silicone-based defoamer (0.1) Silicone-based defoamer (0.01) Silicone-based defoamer (0.1) Corrosion protection Neutral calcium sulfonate (0.5) - Neutral calcium sulfonate (0.49) Glide improver - - PAO 6 (3.0) Example 16: Effect of the lubrication improver on the sliding properties from lubricants

[0123] To investigate the effect of the sliding improver on the sliding properties of lubricants, the change in transition speed at a white metal / steel contact surface is determined at low contact pressure. The transition speed is defined as the speed at which the contact surfaces completely separate, that is, the speed at which the transition from mixed friction (i.e., intermittent contact of the metallic friction partners / incompletely formed lubricating film) to the elastohydrodynamic (EHL) regime (i.e., fully formed lubricating film and complete separation of the metallic friction partners by the lubricating film) occurs.

[0124] The tests are performed using a tribometer (ball-disc tribometer from AC 2< Tresearch / Austrian Competence Center for Tribology) with the cylinder-on-ring test combination. A 10 × 10 mm (diameter × length) 100Cr6 steel cylinder with a surface roughness Ra of approximately 0.02 µm is rubbed against a white metal ring with a surface roughness Ra of approximately 1.3 µm under a defined load. The white metal ring is immersed in an oil reservoir.

[0125] Stribeck curves (friction-velocity curves) are obtained by measuring friction coefficients through continuous variation of the speed of the white metal ring from low to high speed (0.05 m / s - 2.5 m / s) and vice versa (2.5 m / s - 0.05 m / s).

[0126] Before the test began, a warm-up procedure was performed. This included velocity ramps from 0.05 m / s to 2.5 m / s and then from 2.5 m / s to 0.05 m / s at 10 N and 20 N at room temperature and at 10 N at 40°C.

[0127] The Stribeck curve is then generated at 20 N at 40°C with a velocity ramp from 0.05 m / s to 2.5 m / s.

[0128] Fig. 1 Figure 1 shows the measurement of the Stribeck curves for a basic formulation without a sliding improver (Comparison Example 1) and a lubricant according to the invention with a sliding improver (Example 8). It can be seen that in the presence of the sliding improver, the transition velocity shifts significantly towards a lower velocity (A to B).

[0129] In Fig. 2 The transition rate of all tested lubricants is shown. As shown from Fig. 2As can be seen, the investigated lubricant according to the invention with a sliding improver (Example 8) exhibits a significantly lower transition velocity than a basic formulation (Comparative Example 1) as well as a lubricant composition containing a non-inventive sliding improver (Comparative Example 5), which indicates that the lubricant according to the invention, which contains the sliding improver according to the invention, forms the lubricating film much earlier than those of the comparative examples. The improved lubricating properties of the lubricant according to the invention with sliding improver show that it results in an improved load-bearing capacity, for example in plain bearings and similar components. Example 17 - Determination of the sliding behavior using elastomer dynamic measurements:

[0130] The tests are carried out according to the test procedure of Hüttinger, Hermes, Wöppermann (Hüttinger, Hermes, Wöppermann, Prem (2015): New test procedure for dynamic seals of geared motors. In: Berger and Kiefer (eds.) Sealing Technology Yearbook 2016, Mannheim: Isgatec) on a test bench based on DIN 3761-10:1984-10 (Beuth (ed.): DIN 3761, Radial shaft seals for motor vehicles, 1984).

[0131] The conditions / measurement parameters are selected as follows: Elastomer material: 75 FKM 585; Pressure: 0.25 bar; Temperature: 70°C; Test duration: 240 h; 10 cycles at 2000 rpm (20 h) and 0 rpm (4 h); Lubrication: Bremer & Leguil Cassida GTS 2.

[0132] The dynamic elastomer compatibility is determined by means of elastomer-dynamic measurements on FKM radial shaft seals from Freudenberg BAU3 38-90-12 75FKM585 (Art. 49385291 / 49370995) according to the test procedure described above, when using a lubricant composition according to the invention (Example 3) and a lubricant composition according to Reference Example 15b. Subsequently, the running width and the shaft entry are measured, which represent a measure of the sliding behavior and the elastomer compatibility of the lubricant composition, respectively. A basic formulation without lubricant improvers (Comparison Example 2) serves as a control.

[0133] The results of the measurements are summarized in Table 3: Table 3: A-RWDR- BAU3 38-90-12 75FKM585 (Art. 49385291 / 49370995) 70°C Example 3 Ref.Ex. 15b See example 2 See example 4 Track width (wear) / Max. value [mm] 0,35 0,54 0,66 0,75 Shaft lead-in [µm] 0 14 20 30

[0134] The measurement results show that, with the lubricant composition according to the invention with a sliding agent (Example 3: GV 1), compared to Comparative Example 2, a reduction in the radial shaft seal raceway / wear width from 0.66 mm to 0.35 mm (Example 3) (or 0.54 mm in Reference Example 15b) and a reduction in the shaft run-in from 20 µm to 0 µm (Example 3) (or 14 µm in Reference Example 15b) is achieved compared to the base formulation without a sliding agent (Comparative Example 2). As the measurement results for Comparative Example 4 show, however, no improvement is achieved by increasing the viscosity of the base formulation (mPAO 150 / Comparative Example 4 compared to mPAO 65 / Comparative Example 2). Example 18 - Determination of the sliding behavior of elastomers as friction partners using DES (Dynamic Elastomer Screening):

[0135] The tests are performed using a "ring-disc tribometer" based on a further development of the setup described by Sommer M. and Haas W. ([1] Sommer, M., Haas, W. "A new approach on grease tribology in sealing technology: Influence of the thickener particles", Tribology International (2016), 103, 574-583). FKM elastomer material is used as the test material. The counterbody is a steel counterbody.

[0136] The lubricant composition to be investigated is examined on a ring-disc tribometer, as described in [1], at a constant speed of 1.5 m / s and a temperature of 60°C at a line load of 0.90 N / mm in order to provoke a breakdown of the lubricant film and solid contact in the event of poor lubricant film formation.

[0137] How the Figures 3A to 3DAs can be seen, the lubricant composition according to the invention with sliding improver (Example 14; GV 1) shows a significantly smoother and lower coefficient of friction over time. µ This indicates a stable lubricating film formation and supports hydrodynamic lubrication. This suggests a more stable tribosystem (elastomer / lubricant / steel counterbody) with reduced wear (see Figures 4A, 4B ). The basic formulation without lubricant improvers (comparison example 3) shows an unstable lubricant film formation, which manifests itself in a strong fluctuation and a higher coefficient of friction.

[0138] This suggests, at least locally, solid contact and a pronounced stick-slip effect.

[0139] As in the Figures 4A and 4BAs shown, the addition of the sliding improver reduces wear on the elastomer body by 57% (Reference Example 2: GV 3), 50% (Inventive Example 14, GV 1), 67% (Reference Example 11, GV 2) or 63% (Reference Example 5, GV 5), and reduces wear on the steel counterbody by 80% (Reference Example 2: GV 3), 67% (Inventive Example 14: GV 1), 67% (Reference Example 11: GV 2) or 73% (Reference Example 5: GV 5), in each case compared to the basic formulation without sliding improver (Comparative Example 3). Example 19: Effect of the lubrication improver on resistance to micropitting

[0140] Resistance to micropitting is tested on a Micro-Pitting Resistance (MPR) test bench (PCS Instruments, London, UK). Micropitting refers to damage to gear contacts.

[0141] The test rig uses a triple configuration in which a central roller is in contact with three discs, resulting in three roller contact cycles per roller revolution. The two lower discs are partially immersed in oil, which they transport into the contact area during the test, thus simulating immersion lubrication. The roller and discs are driven by separate motors, allowing for the simulation of various sliding-to-rolling ratios (SRR). The tests are conducted at a Hertzian contact pressure of 1.7 GPa, an SRR of 20% to 30%, an oil temperature of 90°C, and 10 million cycles. The coefficient of friction and vibration were recorded during the test using a torque meter and an accelerometer, respectively. At the end of the test, the test roller is cleaned with a solvent to remove any residual oil, its weight is determined, and images of the contact surface are taken using an optical microscope.The ability of a lubricant composition to resist micropitting is determined by the weight loss (comparison of weight before and after measurement) of the roller (see . Fig. 5A ) as well as by changing the wear track width (see Fig. 5B ) rated.

[0142] The results of the MPR measurements from Fig. 5A show that in lubricant compositions according to the invention with sliding improver (see examples 1, 6, 12) a significant reduction in weight loss can be seen compared to a basic formulation without sliding improver (see comparative example 2).

[0143] The results of the MPR measurements from Fig. 5B show that in lubricant compositions according to the invention with sliding improver (see example 10) a significant reduction in the running track width can be seen compared to a basic formulation without sliding improver (see comparative example 4).

Claims

1. Lubricant composition comprising: A) a base oil selected from oil-soluble polyglycols, polyalphaolefins, metallocene polyalphaolefins, white oils, mineral oils, farnesene-based oils, estolides, and mixtures of two or more of these; B) 0.01-10% by weight of at least one additive, based on the total weight of the lubricant composition; and C) 0.001-5% by weight, based on the total weight of the lubricant composition, of an organic compound comprising both a polar and a nonpolar molecular moiety, as lubricity improver, wherein the organic compound has a relative permittivity εr in the range from 1.5 to 10, and a quotient ∫ S1 / ∫ S2 for the organic compound is in the range from 1 to 25, wherein ∫ S1 denotes the sum total of the area(s) of the IR absorption band(s) in the wavenumber range of 3100-2750 cm-1 in an ATR spectrum of the organic compound, and ∫ S2 denotes the sum total of the area(s) of the IR absorption band(s) in the wavenumber range of 1800-1650 cm-1 in an ATR spectrum of the organic compound, and wherein the organic compound is selected from maleic acid-olefin copolymers; and wherein the lubricant composition comprises, as an additional component D), 10-85% by weight of an ester compound, based on the total weight of the lubricant composition, wherein the ester compound is selected from natural glyceride esters, polyol esters, polyol complex esters, dimer acid esters and dimer acid complex esters, aliphatic carboxylic and dicarboxylic esters, trimellitic and pyromellitic esters, and phosphate esters, and mixtures of two or more of these.

2. Lubricant composition according to Claim 1, wherein the at least one additive is selected from antioxidants, antiwear additives, friction modifiers, high-pressure additives, anticorrosives, nonferrous metal deactivators, ion complex formers, solid-state lubricants, dispersants, pour point and viscosity improvers, UV stabilizers, emulsifiers, colour indicators and defoamers.

3. Lubricant composition according to either of Claims 1 and 2, wherein the lubricant composition comprises: A) a base oil; B) 0.5-7% by weight of the at least one additive, based on the total weight of the lubricant composition; C) 0.1-5% by weight of the organic compound, based on the total weight of the lubricant composition; and D) 10-85% by weight of the ester compound, based on the total weight of the lubricant composition, where the constituents present add up to a total of 100% by weight.

4. Lubricant composition according to any of Claims 1 to 3, wherein the ester compound is selected from neopentyl glycol esters, trimethylolpropane esters and pentaerythritol esters that have been esterified with saturated and / or mono- or polyunsaturated, linear and / or branched monocarboxylic acids of chain length C4-C36; and neopentyl glycol complex esters, trimethylolpropane complex esters and pentaerythritol complex esters that have been fully esterified or partly esterified with saturated and / or mono- or polyunsaturated, linear and / or branched monocarboxylic acids of chain length C4-C36 and with saturated and / or mono- or polyunsaturated, linear and / or branched dicarboxylic acids of chain length C4-C36 in any mixture; and mixtures of two or more of these.

5. Lubricant composition according to any of Claims 1 to 4, wherein the at least one additive is an additive mixture comprising: one or more antioxidants, selected from aminic antioxidants, phenolic antioxidants, phosphites, phosphorothionates and thiocarbamates; one or more nonferrous metal deactivators, selected from triazole compounds, salicylates and mercaptothiadiazoles, and derivatives thereof; one or more anticorrosives, selected from neutral carboxylic acid, sulfonic acid, naphthalenesulfonic acid, benzenesulfonic acid, benzoic acid, naphthoic acid, naphthenic acid and phosphoric acid metal salts, and N-methylglycine and derivatives thereof; optionally one or more defoamers, selected from ethoxylated and / or propoxylated alcohols having chain lengths of 10-18 carbon atoms, polyols, acrylates and polysiloxanes; and optionally one or more antiwear and / or high-pressure additives, selected from amines, amine phosphates, branched and / or linear alkylated phosphates, phosphites, thiophosphates, and phosphothionates, aryl phosphates, alkylated polysulfides, sulfonated amine compounds, sulfonated fatty acid methyl esters, naphthenic acids, nanoparticles selected from Al2O3, SiO2, TiO2, ZrO2, WO3, Ta2O5, V2O5, CeO2, aluminium titanate, BN, MoSi2, SiC, Si3N4, TiC, TiN, ZrB2, clay minerals and mixtures thereof, sulfonic salts, and thermally stable carbonates and sulfates.

6. Lubricant composition according to any of Claims 1 to 5, comprising A) a base oil, selected from oil-soluble polyglycols, polyalphaolefins and metallocene polyalphaolefins, and mixtures of two or more of these; B) 0.5-5% by weight of an additive mixture comprising one or more aminic antioxidants, one or more neutral sulfonic acid, naphthalenesulfonic acid and / or benzenesulfonic acid metal salts, one or more triazole compounds and / or derivatives thereof, and one or more polysiloxanes; C) 0.1-5% by weight of the organic compound; and D) 10-85% by weight of pentaerythritol esters; where the stated amounts are each based on the total weight of the lubricant composition and the constituents present add up to a total of 100% by weight.

7. Use of a lubricant composition according to any of Claims 1 to 6 as gear oil, roller bearing oil and slide bearing oil for industry in general, especially for lubrication of transmissions, such as spur, bevel, planetary, worm, hypoid and cycloid gears, hydraulics, linear guides, pneumatic components, instruments, bearings, such as slide and roller bearings, chains, cables, springs, propellers and compressors, and especially of machine components and in systems that come into occasional unintentional contact with foodstuffs.

8. Use of a lubricant composition according to any of Claims 1 to 6 as gear oil, roller bearing oil and slide bearing oil in the marine sector and in inland waterways, especially for lubrication of transmissions, hydraulics, propeller rudders, propeller shafts, linear guides, pneumatic components, instruments, bearings, such as slide, roller or stern tube bearings, chains, cables, springs and propellers in machines, machine components and systems that come into contact with saltwater in the marine sector or with water and / or aqueous media in inland waterways, and in machines and machine elements on land that may come into contact with water and / or aqueous media.