EP4143281A1

EP4143281A1 - Lubricant composition and use thereof

Info

Publication number: EP4143281A1
Application number: EP21721887.4A
Authority: EP
Inventors: Stefan Seemeyer; Patrick WITTMEYER; Maximilian ERHARD; Maria FRACKOWIAK; Balasubramaniam Vengudusamy
Original assignee: Klueber Lubrication Muenchen SE and Co KG
Current assignee: Klueber Lubrication Muenchen GmbH and Co KG
Priority date: 2020-04-27
Filing date: 2021-04-21
Publication date: 2023-03-08
Also published as: US20230174885A1; CN115443325A; JP7422886B2; WO2021219456A1; KR20220112271A; JP2023512001A; DE102020111403A1

Abstract

The present invention relates to a biodegradable lubricant composition and its use as transmission oil, rolling bearing oil, hydraulic oil or sliding bearing oil in the marine field and in the field of fresh waters, as well as in on-shore machines and machine elements that may come in contact with water and/or aqueous media.

Description

Lubricant composition and its use

The present invention relates to biodegradable lubricant compositions and their use as gear, roller bearing, hydraulic and plain bearing oil in the marine sector and in inland waterways, as well as in machines and machine elements on land that can come into contact with water and / or aqueous media.

When using lubricants or

Lubricant compositions as gear, roller bearing, hydraulic and plain bearing oil in the marine area and in inland waters, i.e. applications in which the lubricants or lubricant compositions are usually used below the water lines in oil-to-water interfaces, there is a risk that the marine or water environment is contaminated by the leakage of the lubricant, caused for example by leaks. Although attempts are made to seal the water side as best as possible in these applications, lubricant losses are commonplace. Lubricants that are used in machines and machine elements on land, especially in the mining industry, in wind turbines and in agricultural machinery, can come into contact with water, for example through rain. In addition, leakages often occur here too, which can lead to contamination of the environment and pollution of the soil by chemicals.

In recent years the protection of the environment has become more and more important, especially the protection of the oceans. Proof of this are various new legislations for the protection against pollution of the marine environment, which require the use of lubricants that are harmless to the marine climate. For example, the Vessel General Permit (VGP) of the United States Environmental Protection Agency requires the use of so-called Environmentally Acceptable Lubricants (EALs) for lubricants that are used below the water lines, which must meet high requirements with regard to biodegradability and aquatoxicity.

The selection and quantity of base oil components and additives that can be used for a lubricant is therefore limited. Common EALs are therefore made on the basis of natural and synthetic esters instead of the conventional one Mineral oil base. Compared to mineral oil-based lubricants, however, the use of EALs often results in damage to sealing materials.

In the marine area and in the inland waters, as well as in machines and machine elements on land, there are usually radial shaft seals, which are usually made of elastomer materials such as FKM (fluorine rubber), NBR (nitrile butadiene rubber), HNBR (hydrogenated nitrile butadiene rubber), ACM / AEM (acrylate elastomers / ethylene acrylic elastomers) and polyurethanes are used to seal slide bearings such as the stern tube, gears such as Azipods and linear guides, e.g. for rudder stabilizers. Damage to seals, which ultimately result in leaks, is caused in particular by incompatibility of lubricant and sealing material. Therefore, the selection of the base oil component (s) for the lubricant and the carefully coordinated selection of additives are essential in order to ensure not only good biocompatibility but also material compatibility of the lubricant and thus prevent damage to sealing materials.

WO 2012/173878 A1 describes ester-based lubricant compositions which contain water-soluble polyalkylene glycols based on ethylene oxide and propylene oxide.

WO 2015/139209 A1 describes a lubricant which contains an alcohol-initiated propylene oxide homopolymer and an oil-soluble polyalkylene glycol and which does not require an ester-based base oil.

EP 2 837 674 A1 describes a lubricating oil composition which can contain a base oil mixture of synthetic oils based on polyglycol and a synthetic oil based on esters and also contains an asymmetric amine-based antioxidant.

However, there is still a need for ecologically harmless lubricants that reduce the pollution of the seas, inland waters and soils with chemicals and that are highly compatible with sealing materials, especially elastomer materials, and that also meet the usual requirements for the lubrication of, for example, plain bearings, Gearboxes, linear guides, pneumatic components, fittings, roller bearings, chains, ropes, springs and screws, etc.

The object of the present invention was therefore to provide lubricants or lubricant compositions which have improved compatibility with sealing materials, in particular elastomers, which are good Have lubricating properties and good sliding properties, which are biocompatible, i.e. readily biodegradable and minimally aquatoxic, and which are used as gear, roller bearing, hydraulic and plain bearing oil in the marine area and in inland waters, as well as in machines and machine elements on land, which may come into contact with water and / or aqueous media, are suitable.

For the purposes of the invention, the terms lubricant composition, lubricant, lubricating oil and formulation are used synonymously.

One or more of the above-mentioned objects can be achieved by a lubricant composition comprising an oil-soluble polyalkylene glycol, an ester compound selected from the group of natural esters and synthetic esters, and combinations thereof, and an additive mixture comprising an antioxidant and a corrosion protection agent, contains, the corrosion protection agent being selected from neutral alkali and alkaline earth salts of sulfonic acids, carboxylic acids, naphthoic acids, naphthenic acids, benzoic acids and phosphoric acids, and their derivatives and combinations thereof. s

Surprisingly, it has been found that in the lubricant composition according to the invention, which contains an oil-soluble polyalkylene glycol, an ester compound and an additive mixture as components as defined below, the additive mixture comprising an antioxidant and a neutral corrosion protection agent, the components interact synergistically. The lubricant composition according to the invention therefore surprisingly shows the advantage of improved compatibility with sealing materials, in particular elastomer materials such as FKM, NBR, HNBR, ACM / AEM, or polyurethanes. In addition, the lubricant composition according to the invention has good lubricating properties and is also generally characterized by good biodegradability and / or aquatoxicity, so that it is excellent for use as gear, roller bearing, hydraulic or plain bearing oil in the marine area 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.

According to the invention, the lubricant composition contains an oil-soluble polyalkylene glycol (OSP) as the base oil component Invention also mixtures of two or more different oil-soluble

Polyalkylene glycols are included.

In the context of the invention, a polyalkylene glycol is “oil-soluble” if, after it has been mixed with polyalphaolefin 6 (for example, available as Synfluid® PAO 6 cSt or Durasyn® 166 polyalphaolefins) in the weight ratios 10:90, 50:50 and 90:10 and after allowing the mixtures to stand for 24 hours at room temperature, no phase separation occurs in at least two of the three mixtures.

In a preferred embodiment of the present invention, the oil-soluble polyalkylene glycol is a copolymer selected from polybutylene oxide-polypropylene oxide copolymers, polybutylene oxide-polyethylene oxide copolymers, and polybutylene oxide-polypropylene oxide-polyethylene oxide copolymers, and combinations thereof, with polybutylene oxide-polypropylene oxide copolymers in particular are preferred. It is furthermore preferred if the copolymer is alcohol-initiated, that is to say if, in its preparation, an alcohol was used as the initiator of the polymerization reaction, as is described in more detail below.

The oil-soluble polyalkylene glycol is particularly preferably a copolymer selected from polyisobutylene oxide-polyisopropylene oxide copolymers, polyisobutylene oxide-polyethylene oxide copolymers and polyisobutylene oxide-polyisopropylene oxide

Polyethylene oxide copolymers, as well as combinations thereof, with polyisobutylene oxide-polyisopropylene oxide copolymers being very particularly preferred.

It is particularly preferred here if the proportion of the butylene oxide or isobutylene oxide derived (polymerized) monomer units (ie, polybutylene oxide (BO) or polyisobutylene oxide (iBO) units) in the abovementioned copolymers is 40 percent by weight (% by weight) or more, more preferably 50% by weight or more, for example 60% by weight or more, or 65% by weight or more, and preferably 80% by weight or less, more preferably 70% by weight or less, based on the total weight of all Monomer units in the copolymer. A polyalkylene glycol copolymer with 50% by weight of butylene oxide or isobutylene oxide derived (polymerized) monomer units (ie, BO or iBO units) and 50% by weight of propylene oxide (polymerized) monomer units (ie, Polypropylene oxide (PO) or polyisopropylene oxide (iPO) units), based on the total weight of BO- (or iBO-) and PO- (or iPO-) Units in the copolymer. This means that BO (or iBO) and PO (or iPO) units are very particularly preferably copolymerized with a weight ratio of 50:50.

According to the invention, the oil-soluble polyalkylene glycol copolymer can be a random copolymer, a gradient copolymer, an alternating copolymer, a graft copolymer or a block copolymer, random copolymers and block copolymers being preferred, and in particular random copolymers.

Furthermore, it is preferred if the oil-soluble polyalkylene glycol is an alcohol-initiated polyalkylene glycol. That is, the oil-soluble polyalkylene glycol used according to the invention is preferably a polyalkylene glycol which is prepared using an alcohol as the initiator of the polymerization reaction, the alcohol preferably comprising 10-20 carbon atoms, particularly preferably 12-20 carbon atoms, so that the polyalkylene glycol has at least one terminal At the end of this, a C10-C20-alkyl radical (preferred) or C12-C20-alkyl radical (particularly preferred) has bonded, which results from the initial reaction of the alcohol with an alkylene oxide. The alcohol initiator is also preferably a linear alcohol, and in particular a primary linear alcohol. In addition, the alcohol initiator can be a mono-, di- or tri-alcohol, a mono-alcohol being preferred.

If the alcohol used as the polymerization initiator has 10-20 carbon atoms, or if the alcohol-initiated polyalkylene glycol has a C10-C20 alkyl radical bonded to at least one terminal end, the compounds added as additives, in particular antioxidants and corrosion inhibitors (see below), can be better dissolved therein will. A very particularly preferred alcohol initiator in this regard is n-dodecanol.

According to the invention, it is therefore particularly preferred if the oil-soluble polyalkylene glycol is a dodecanol-initiated polyalkylene glycol copolymer, dodecanol-initiated polybutylene oxide-polypropylene oxide copolymers being particularly preferred and polyisobutylene oxide-polyisopropylene oxide copolymers being very particularly preferred.

Furthermore, it is preferred that the oil-soluble polyalkylene glycol have a number average molecular weight (M _n ) of 500 g / mol (grams per mol) or more, particularly preferred of 750 g / mol or more, for example 1000 g / mol or more, or 1250 g / mol or more. In addition, it is preferred that the molecular weight of the oil-soluble polyalkylene glycol is 1400 g / mol or less, and M _n is particularly preferably less than 1400 g / mol.

Unless explicitly stated otherwise, “molecular weight” in the context of this invention refers to the “number average molecular weight (M _n )”.

The molecular weight is determined by means of GPC (gel permeation chromatography) against a polystyrene standard.

Oil-soluble polyalkylene glycols with a molecular weight M _n of 500 g / mol or more to 1400 g / mol or less are advantageous with regard to their biodegradability. In addition, it has been found that the use of such oil-soluble polyalkylene glycol copolymers has an advantageous effect on the compatibility of the lubricant composition with elastomer materials.

In a further preferred embodiment of the invention, the oil-soluble polyalkylene glycol is biodegradable according to standard OECD 301 A-F or OECD 306 in order to achieve improved biodegradability and ecological compatibility of the lubricant composition according to the invention.

Furthermore, the oil-soluble polyalkylene glycol preferably has a kinematic viscosity at 40 ° C. of 15 mm ² / s or higher, more preferably 18 mm ² / s or higher, particularly preferably 32 mm ² / s or higher, for example 68 mm ² / s cSt or higher, and of 130 mm ² / s or less, more preferably 100 mm ² / s or less. The viscosity is determined in accordance with ASTM D 7042.

Oil-soluble polyalkylene glycols suitable according to the invention are commercially available, for example under the brand names UCON ™ OSP-18, UCON ™ OSP-32, UCON ™ OSP-68 and UCON ™ OSP-680.

The amount of the oil-soluble polyalkylene glycol in the lubricant composition is usually determined on the basis of the amounts of the other constituents / components contained in the composition, that is, the lubricant composition is made up to 100% by weight with the oil-soluble polyalkylene glycol. However, the amount of the oil-soluble polyalkylene glycol is preferably 0.1-70% by weight, particularly preferred 5-70% by weight, and very particularly preferably 10-70% by weight, based on the total weight of the lubricant composition.

The lubricant composition according to the invention also contains, as a further base oil component, an ester compound selected from the group of natural esters and synthetic esters, as well as combinations thereof, including mixtures of two or more different natural esters or mixtures of two or more different synthetic esters are included according to the invention.

In a preferred embodiment of the present invention, the ester compound is selected from natural glyceride esters, in particular from the group consisting of sunflower oil, rapeseed oil or rapeseed oil, linseed oil, corn oil, diestel oil, soybean oil, linseed oil, peanut oil, "Lesqueralle" oil, palm oil, olive oil which can each be in their monomeric, oligomeric and / or polymerized form; and synthetic esters from the group of polyol esters, polyol complex esters, complex esters of dimer acids, dimer acid esters, aliphatic carboxylic acid and dicarboxylic acid esters, phosphate esters and trimellitic and pyromellitic acid esters; as well as combinations from it.

The ester compound is particularly preferably selected from polyol esters, especially those obtained by reacting polyhydric alcohols (that is to say polyols or alcohols with more than one hydroxyl group) with monocarboxylic acids (that is, monobasic carboxylic acids), and polyol complex esters , especially those which are obtained by reacting polyhydric alcohols with monocarboxylic acids and dicarboxylic acids (that is, dibasic carboxylic acids) in any desired mixture, as well as combinations thereof.

The polyol esters used according to the invention are particularly preferably prepared by reaction / esterification of one or more polyhydric alcohols selected from neopentyl glycol (NPG), trimethylolpropane (TMP) and pentaerythritol (PE), or dimers or trimers thereof, with one or more linear and / or branched monocarboxylic acids of chain length C4-C36 (that is, 4 to 36 carbon atoms), preferably C10-36, particularly preferably C14-C36, and very particularly preferably C18-C36, which can be saturated and / or mono- or polyunsaturated, and preferably are saturated. The polyol complex esters used according to the invention are also particularly preferably prepared by reaction / esterification of one or more polyhydric alcohols selected from neopentyl glycol (NPG), trimethylolpropane (TMP) and pentaerythritol (PE), or dimers or trimers thereof, in any mixture with one or more linear and / or branched monocarboxylic acids of chain length C4-C36, preferably C10-36, particularly preferably C14-C36, and very particularly preferably C18-C36, which can be saturated and / or mono- or polyunsaturated, and are preferably saturated, and one or more linear and / or branched dicarboxylic acids of chain length C4-C36, preferably C4-C18, particularly preferably C4-C12, which can be saturated and / or mono- or polyunsaturated, and are preferably saturated.

The polyol complex esters obtained in this way can be completely esterified or partially esterified (i.e. there are still free, unesterified hydroxyl groups).

In a very particularly preferred embodiment of the invention, the ester compound is therefore selected from neopentyl glycol esters, trimethylol propane esters, and pentaerythritol esters, which are 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 very particularly preferably C18-C36 are esterified; and neopentyl glycol complex esters, trimethylolpropane complex esters, and pentaerythritol complex esters, 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 very particularly preferably C18-C36, and are completely esterified or partially esterified in any mixture 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; as well as combinations thereof.

Examples of particularly preferred ester compounds are pentaerythritol tetraisostearate, pentaerythritol tetraoleate, pentaerythritol isostearate sebacate complex ester,

Trimethylolpropane triisostearate, trimethylolpropane trioleate, trimethylolpropane tricaprylate, trimethylolpropane isostearate stearate sebacate complex ester, neopentyl glycol

Diisostearate, without being limited to it. Suitable ester compounds are also commercially available, for example under the brand names Priolube3987, Radialube 7257, Synative ES 1200, Priolube 1973, Synative ES TMP 05/140, Palub 8433, Nycobase 8397, Estilube P 688, Rümanox 804.

It has been shown that the presence / addition of such ester compounds, and in particular those which contain the remainder of a monocarboxylic acid of chain length C18-C36, has an advantageous effect on the compatibility with elastomer materials. The ester compounds defined above are also generally characterized by good biodegradability.

In a further preferred embodiment of the invention, ester compounds are used which are biodegradable according to standard OECD 301 A-F or OECD 306 in order to achieve improved biodegradability and ecological compatibility of the lubricant composition according to the invention.

The ester compound is in the lubricant composition according to the invention preferably in an amount of 0.1-85% by weight, more preferably 5-85% by weight, particularly preferably 10-85% by weight, and very particularly preferably from 15 - 85% by weight, based on the total lubricant composition.

According to a particularly preferred embodiment of the invention, the oil-soluble polyalkylene glycol and the ester compound are the only base oil components in the lubricant composition, that is, the lubricant composition according to the invention contains only oil-soluble polyalkylene glycol as base oil components - a single compound or a mixture of different OSPs - and ester compound - a Single compound or a mixture of different ester compounds - but no other base oil components, especially no mineral oil.

The weight ratio “oil-soluble polyalkylene glycol” to “ester compound” based on the total weight of these two components in the lubricant composition is preferably in the range from 5:95 to 95: 5, more preferably from 10:90 to 80:20, and particularly preferably from 15:85 to 70:30.

The lubricant composition according to the invention furthermore contains an additive mixture which comprises an antioxidant and a corrosion protection agent. The antioxidant and the anti-corrosion agent can each be used as a single substance or as a mixture of different antioxidants, respectively Corrosion inhibitors are present in the lubricant composition. The same also applies to any other additive that may be contained in the lubricant composition.

The targeted addition of additives can improve certain properties of the lubricant and / or give the lubricant certain properties.

The addition of anti-corrosion agents gives the lubricant composition an anti-corrosion and rust-inhibiting effect.

According to the invention, the corrosion protection agent is selected from neutral alkali and alkaline earth salts of sulfonic acids, carboxylic acids, naphthenic acids, naphthoic acids, benzoic acids and phosphoric acids, and combinations thereof. In the context of the present invention, this also includes derivatives of the acids / acid salts mentioned, including linear and branched aliphatic and aromatic derivatives of these acids / acid salts, which also have one or more radicals selected from linear and / or branched alkyl radicals and Aryl radicals, can be substituted. Among the alkali and alkaline earth salts of these acids, the Na, Ca, K and Mg salts are preferred, and Ca salts are particularly preferred, in particular for reasons of environmental compatibility.

In the context of the present invention, “neutral” acid salts are understood to mean acid salts which have an acid number (TAN) of 30 mg KOH / g or less.

It is therefore preferred in the context of the present invention that the corrosion protection agent or the neutral sulfonic acid, carboxylic acid, naphthenic acid, naphthoic acid, benzoic acid or phosphoric acid salt, or mixtures thereof, have a TAN of 30 mg KOH / g or less, more preferably 20 mg KOH / g or less, particularly preferably 15 mg KOH / g or less, and very particularly preferably 10 mg KOH / g or less.

In a particularly preferred embodiment, the corrosion protection agent is selected from neutral calcium sulfonates. These have proven to be particularly advantageous with regard to the compatibility of the lubricant composition with elastomer materials. An example of one particularly according to the invention Suitable anti-corrosive agents are neutral alkylnaphthalenesulfonic acid calcium salts, without being restricted thereto.

Suitable neutral corrosion protection agents are commercially available, e.g. under the brand names NA-SUL® CA-770 FG or NA SUL® CA 1089.

It has surprisingly been found that the targeted addition of the neutral acid salts as defined above to the lubricant composition, in addition to the corrosion and rust-inhibiting effect, improves the compatibility of the lubricant composition with sealing materials, in particular elastomer materials, which is achieved in particular from a synergistic interaction with the other components of the lubricant composition results.

The oxidation stability of the lubricant composition can be increased by adding antioxidants.

In a preferred embodiment of the present invention, the antioxidant is selected from phenolic antioxidants (phenol compounds), aminic antioxidants (amine compounds), phosphites and sulfur-containing compounds, in particular alkyl and aryl sulfides, sulfur-containing phenol compounds and sulfur-containing carboxylic acids, phosphorothionates, thiocarbamates and dithiocarbamates, thiophosphates and thiopropionates, and combinations thereof, with phenolic antioxidants, aminic antioxidants, thiocarbamates and dithiocarbamates being particularly preferred. The antioxidant is very particularly preferably selected from aminic antioxidants, and in particular from linear or branched aliphatic amine compounds and aromatic amine compounds and salts thereof, the aliphatic and aromatic amine compounds having one or more radicals selected from linear and / or branched alkyl radicals and aryl radicals, may be substituted.

Preferred antioxidants are selected from aromatic diamines and secondary aromatic amines, phenolic resins, thiophenolic resins, zinc thiocarbamate, zinc thiophosphate, organic thiocarbamates and dithiocarbamates, butylated hydroxytoluene, butylated hydroxyanisole, phenyl-alpha-naphthylamines, phenyl-beta-amines naphthylamines, diphenylamine and diphenylamine derivatives, in particular octylated diphenylamines, butylated diphenylamines and styrenated diphenylamines, quinoline and quinoline derivatives, naphthylamine and naphtylamine derivatives, di-alpha-tocopherol, di- te / f-butyl-phenylpropanic acid and their esters Mixtures thereof, without being limited to them.

Examples of antioxidants particularly preferred according to the invention are benzolamine, 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 4,4'-methylenebis (dibutyldithiocarbamate), without being restricted to this .

Suitable antioxidants are commercially available, e.g. under the brand names Vanlube® 81, Irganox® L 57, Vanlube® 1202 or Irganox® L 107 ADDITIN RC 6340.

It was surprisingly found that through the targeted selection of the antioxidant, in particular the targeted use of amine compounds, phenol compounds and / or thiocarbamates and dithiocarbamates as antioxidants, in addition to increasing the oxidation stability, an improvement in the compatibility of the lubricant composition with sealing materials, in particular Elastomer materials, can be achieved, which results in particular from a synergistic interaction with the other components of the lubricant composition.

The amount of the additive mixture in the lubricant composition, that is to say the total amount of all additives in the lubricant composition, is preferably 0.1-20% by weight, more preferably 0.1-10% by weight, and particularly preferably 0.1 -5% by weight, based on the total lubricant composition. The amount of the antioxidant is preferably in the range of 0.05-3.5% by weight and the amount of the corrosion protection agent is preferably in the range of 0.05-3.5% by weight, based in each case on the total lubricant composition, the the total amount of all additives defined above is not exceeded.

In a preferred embodiment, the present invention therefore relates to a lubricant composition containing an oil-soluble polyalkylene glycol; in an amount of 0.1-85% by weight, based on the total lubricant composition, an ester compound selected from the group consisting of natural esters and synthetic esters, as well as combinations thereof; and in an amount of 0.1-20% by weight, based on the total lubricant composition, an additive mixture comprising an antioxidant and a corrosion protection agent, the corrosion protection agent being selected from neutral alkali and alkaline earth salts of sulfonic acids, carboxylic acids, naphthenic acids, Naphthoic acids, benzoic acids and phosphoric acids, and their derivatives and combinations thereof, and where the components contained add up to a total of 100% by weight and are as defined above.

In a further preferred embodiment of the invention, the additive mixture comprises, in addition to antioxidant (s) and corrosion protection agent (s), a non-ferrous metal deactivator, both individual compounds and mixtures of two or more different non-ferrous metal deactivators being included within the scope of the invention.

By adding non-ferrous metal deactivators, non-ferrous metals such as cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), tin (Sn), and zinc (Zn), which belong to the so-called Non-ferrous metals count, as well as their alloys, are protected from corrosion by active sulfur.

The non-ferrous metal deactivator is preferably selected from triazoles, mercaptothiadiazoles and salicylates, and combinations thereof, triazoles and in particular benzotriazoles being particularly preferred. In the context of the present invention, the terms “triazoles” and “benzotriazoles” also include triazole derivatives or benzotriazole derivatives, as well as reaction mixtures and reaction masses in which these are contained as individual compounds or in a large number.

Examples of particularly suitable non-ferrous metal deactivators according to the invention are benzotriazole and tolyltriazole and derivatives thereof, N, N-bis (2-ethylhexyl) -ar-methyl-1H-benzotriazole-1-methanamine, and a reaction mass composed of N, N-bis (2-ethylhexyl) -6- methyl-1H-benzotriazole-1-methanamine, N, N-bis (2-ethylhexyl) -4-methyl-2H-benzotriazole-2- methanamine, N, N-bis (2-ethylhexyl) -5-methyl-2H-benzotriazole-2-methanamine, N, N-bis (2-ethylhexyl) -4-methyl-1H-benzotriazole-1-methylamine and N, N-bis (2-ethylhexyl) -5-methyl-1H-benzotriazole-1-methylamine, without being restricted to this.

Suitable non-ferrous metal deactivators are commercially available, e.g. under the brand names Irgamet® 39 or Irgamet® BTZ.

Through the targeted selection of the non-ferrous metal deactivator, in particular the targeted use of triazoles or benzotriazoles, in addition to the protection against corrosion by active sulfur, a further improvement in the compatibility of the lubricant composition with sealing materials, in particular elastomer materials, can be achieved, in particular from a synergistic interaction with the others Components of the lubricant composition results.

In a further preferred embodiment, the present invention therefore relates to a lubricant composition containing an oil-soluble polyalkylene glycol; in an amount of 0.1-85% by weight based on the total

Lubricant composition, an ester compound selected from the group of natural esters and synthetic esters, and combinations thereof; and in an amount of 0.1-20% by weight based on the whole

Lubricant composition, an additive mixture comprising an antioxidant, a corrosion protection agent and a non-ferrous metal deactivator, the corrosion protection agent being selected from neutral alkali and alkaline earth salts of sulfonic acids, carboxylic acids, naphthenic acids, naphthoic acids, benzoic acids and phosphoric acids, and combinations thereof, and the components contained therein add up to a total of 100% by weight and are as defined above.

The lubricant composition according to the invention, or the additive mixture used, can in addition to antioxidant (s), corrosion protection agent (s) and optionally non-ferrous metal deactivator (s) comprise one or more further additives, which are selected in particular from wear protection agents, friction reducers, high-pressure additives, ion complexing agents, solid lubricants, dispersants, pour point and viscosity improvers, UV stabilizers, emulsifiers, color indicators, slip improvers and defoamers, without this to be limited.

Wear protection agents, friction reducers and high-pressure additives suitable according to the invention are preferably selected from amines, amine phosphates, branched and / or linear alkylated phosphates, phosphites, thiophosphates and phosphorothionates, aryl phosphates, aryl thiophosphates, alkylated polysulfides, sulfurized amine compounds, sulfurized fatty acid methyl esters, sulfated fatty acid methyl esters, S1O2, T1O2, ZrC> ₂ , WO3, Ta20s, V2O5, CeC> ₂ , aluminum titanate, BN, M0S12, SiC, S13N4, TiC, TiN, Zrß ₂ , clay minerals and their mixtures, sulfonic acid salts, and thermally stable carbonates and sulfates, as well Mixtures of two or more of these, without being limited thereto. Suitable commercially available additives are, 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.

Suitable viscosity improvers are preferably selected from linear and branched alkylated, acrylated and aliphatic polymers and copolymers and polymerized fatty acid esters, and mixtures of two or more thereof. Examples of suitable viscosity improvers are polymethacrylate, ethylene-propylene copolymer, polyisobutylene, polyalkylstyrene, hydrogenated styrene-isoprene copolymer, without being restricted to these. Suitable viscosity improvers are available for purchase.

Suitable UV stabilizers are preferably selected from nitrogen heterocycles and substituted nitrogen heterocycles, as well as mixtures of two or more thereof, without being restricted thereto. Suitable UV stabilizers are available for purchase.

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, nano-tubes, Si0 ₂ modifications, and mixtures of two or more more of this, without being limited to it. Suitable solid lubricants are available for purchase.

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. B. sodium salts of alkyl sulfonic acids, as well as mixtures of two or more thereof, without being limited thereto. Suitable emulsifiers are available for purchase.

Foam formation is prevented by adding defoamers. 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 Mixtures of two or more of these, without being limited thereto. Suitable defoamers are available for purchase.

An example of a suitable color indicator is 2,5-thiophenediylbis (5-ter-butyl-1,3-benzoxazole), without being limited to this. Suitable color indicators are available for purchase.

A slip improver in the context of the present invention is an organic compound which comprises both a polar and a non-polar part. The term “organic compound” encompasses both individual compounds (that is, molecules) and mixtures of individual compounds as well as oligomers and polymers including homopolymers, copolymers and polymer blends, as well as mixtures thereof.

By adding the anti-slip agent to the lubricant composition, an improvement in the sliding properties of the lubricant composition can be achieved, in particular even at low gear and bearing speeds and high loads.

Preferred examples of organic compounds which can advantageously be used as slip improvers in the lubricant composition according to the invention are the following compounds, without being restricted to them: Maleic acid-olefin copolymers (commercially available, e.g. as Ketjenlube® 135, Ketjenlube® 2700, Ketjenlube® 23000); 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); Glycerine monooleate (GMO), in particular those with a mono content of at least 40%, free glycerine at most 6% (commercially available, for example, as Ilco Lube 2316); Polymethacrylate (PMA), linear polymers and comb polymers (commercially available, for example as Viscoplex® 3-200); Comb polymers made from 1-decene and 9-dodecylic acid methyl ester (commercially available, for example, as Elevance Aria® WTP 40); Pentaerythritol tetraisostearate (commercially available, for example, as Priolube ™ 3987-LQ).

Since the additives serve to improve certain properties of the lubricant and / or to give it certain properties, 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 of the lubricant, the amount of the Additives in the additive mixture is not restricted as long as the total amount of all additives defined above, based on the total lubricant composition, is not exceeded or not reached.

In a further preferred embodiment of the invention, the acid number of the entire lubricant composition is 30 mg KOH / g or less, more preferably 20 mg KOH / g or less, particularly preferably 15 mg KOH / g or less, and very particularly preferably 10 mg KOH / g or smaller.

In a further preferred embodiment, the lubricant composition has a kinematic viscosity at 40 ° C. of 20 mm ² / s to 680 mm ² / s, particularly preferably from 30 mm ² / s to 480 mm ² / s and very particularly preferably 60 mm ² / s to 150 mm ² / s. Viscosity measurements are carried out in accordance with ASTM D 7042.

In a further preferred embodiment, the lubricant composition according to the OECD 301 A - F or OECD 306 standard is biodegradable and / or has a low aquatoxicity according to the OECD 201, 202, 203 or 236 standard.

It has surprisingly been found that the lubricant composition according to the invention described herein, which as defined above as components an oil-soluble polyalkylene glycol, an ester compound and an additive mixture, which a Contains antioxidants and a neutral corrosion protection agent, shows the advantage of improved compatibility with sealing materials, in particular elastomers, which results in particular from a synergistic interaction of the components. The lubricant composition according to the invention also has good lubricating or sliding properties and good biodegradability or ecological compatibility.

The lubricant composition according to the invention is therefore eminently suitable for use as gear, roller bearing, hydraulic or plain bearing oil in the marine area and in inland waterways, as well as in machines and machine elements on land that can come into contact with water and / or aqueous media .

Another object of the present invention therefore relates to the use of the lubricant composition according to the invention described herein as gear, roller bearing, hydraulic and plain bearing oil in the marine area and in inland waters, as well as in machines and machine elements on land that operate with water and / or aqueous Media can come into contact.

Areas of application in the marine sector and in inland waters include, in particular, the lubrication of gears, hydraulics, bearings such as sliding, roller or stern tube bearings, propeller rudders, propeller shafts, pneumatic components, linear guides, chains and ropes in machines, machine components and systems used in the marine sector come into contact with salt water, for example offshore systems, or in inland waters with (fresh) water and / or aqueous media, without being limited to this.

In the marine sector, gears are used in thrusters and azipods, for example. This application is used for power transmission and power conversion, which takes place between the drive and the propeller. Both an entry of water into the interior and an escape of lubricant into the marine environment are to be expected here.

Another application in the marine sector is jack-up systems that raise platforms, installation vessels for wind turbines or oil rigs. This movement is brought about by open gears. Hydraulics in the marine sector are used to drive adjustable propeller rudders, as well as in fin stabilizers and rudder bearings. In the latter, linear guides are also used, which are usually lubricated with the same lubricant. Here, too, lubrication takes place below the waterline. Correspondingly, in this case too, water entry into the machine parts and leakage of the lubricant into the marine environment must be expected.

The plain bearing application in the marine sector is primarily a propeller shaft bearing, which is located in the stern tube, the so-called stern tube bearing. The primary task of the propeller shaft is to transmit the drive movement through the ship's hull to the propeller. The bearing ensures low-friction movement.

In addition, machines and machine components in offshore wind turbines, oil and gas production platforms, in port facilities, shipyards and the like that come into contact with seawater, water and aqueous media are lubricated.

This also includes chains that are used, for example, in lock gates, ropes such as ship ropes or ropes that are used in networks, as well as fittings for regulating solid, liquid and gas flows. Likewise, screws, springs and valves have to be lubricated in a wide variety of devices and machines.

In a preferred embodiment, the present invention therefore relates to the use of those according to the invention described herein

Lubricant composition as gear oil, roller bearing oil, hydraulic oil or plain bearing oil in the marine area 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, roller or stern tube bearings, chains, ropes , Springs, valves and screws in machines, machine components and systems that come into contact with water (salt and / or fresh water), as well as in machines and machine elements on land that come into contact with water and / or aqueous media, whereby the Lubricant composition preferably contains: an oil-soluble polyalkylene glycol; in an amount of 0.1-85% by weight, based on the total lubricant composition, an ester compound selected from Group of natural esters and synthetic esters, as well as combinations thereof; and in an amount of 0.1-20% by weight, based on the total lubricant composition, an additive mixture comprising an antioxidant, a corrosion protection agent and optionally a non-ferrous metal deactivator, the corrosion protection agent being selected from neutral alkali and alkaline earth salts of sulfonic acids, Carboxylic acids, naphthenic acids, naphthoic acids, benzoic acids and phosphoric acids, as well as derivatives and combinations thereof, and where the components contained add up to a total of 100% by weight and are as defined above.

The lubricant compositions are produced according to a procedure known to those skilled in the art, by mixing the base oil components (oil-soluble polyalkylene glycol (s), ester compound (s)) and the additives in a suitable vessel, e.g. a mixing vessel, using a suitable stirrer will. Solid additives or components are brought into solution by increasing the temperature and stirred in. Production can also be carried out by means of continuous processes.

The present invention is described in more detail by the following non-limiting examples.

Examples

General test methods used:

The properties of the lubricant composition and the components it contains are determined using the following methods, unless known from the manufacturer:

Determination of the viscosity: the viscosity is measured in accordance with ASTM D 7042 using a Stabinger viscometer SVM 3000 (Anton Paar).

- Determination of acid number (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 in accordance with ASTM D664-18E02. The titration is carried out potentiometrically with the aid of a Solvotrode on a Metrohm 905 Titrando titration unit. - Determination of molecular weight (M _n ):

The molecular weight is determined by means of GPC (gel permeation chromatography) 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 . Production of the lubricant compositions:

The following inventive (Examples 1-5) and non-inventive (Comparative Examples 1-11) formulations are prepared as described above: Example 1

Example 2

Example 3 Example 4

Example 5 Comparative example 1

Comparative example 2

Comparative example 3

Comparative example 4

Comparative example 5

Comparative example 6

Comparative example 7

Comparative example 8

Comparative example 9

Comparative example 10

Comparative Example 11

Neutral alkylnaphthalenesulfonic acid calcium salt (NA-SUL® CA-770 FG); 2 octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate (CAS # 2082-79-3); 3Benzolamine, N-phenyl, reaction products with 2,4,4-trimethylpentene, (CAS No. 68411-46-1); 4Bis (4- (1, 1, 3,3-tetramethylbutyl) phenyl) amine (CAS No. 15721-78-5);

⁵ A ine, C11-14- branched alkyl, monohexyl and dihexyl phosphates (CAS No. 80939-62-

4);

⁶ N-oleoyl sarcosine;

⁷ 2- (tetrapropenyl) succinic acid, monoester with propane-1,2-diol (CAS No. 52305-09-6); 8 (tetrapropenyl) succinic acid (CAS No. 27859-58-1);

⁹ reaction products of dihydro-3- (tetrapropenyl) furan-2,5-dione with propane-1,2-diol (EC No. 947-696-0);

¹⁰ 4,4'-methylenebis (dibutyldithiocarbamate) (CAS No. 10254-57-6);

¹¹ polypropylene glycol monobutyl ether, n-butanol initiated (Synalox ™ 100-40B DOW, M _n 1100 g / mol);

¹² Barium bis (dinonylnaphthalene sulfonate) in mineral oil (CAS No. 25619-56-1; King Industries Na-Sul ® BSN, pH 10)

Example 6 - Determination of elastomer compatibility: When selecting a suitable elastomer material, in addition to the temperature range of use, the chemical and physical resistance of the elastomer is often taken into account. The elastomers are subject to aging and wear, which in turn are decisive for the service life in the application. To determine the elastomer compatibility with lubricants, elastomer test bodies (NBR and F KM test bodies) are incorporated in the formulations of Examples 1-5 and Comparative Examples 1-7 and the effect of the respective formulation on the elastomer material is investigated. The change in material properties such as hardness, weight, volume, tensile strength or elongation at break after storage in the lubricant in comparison to the delivery condition is determined as a measure of the elastomer compatibility.

Storage tests are carried out both in pure lubricating oil and in an oil-water emulsion using commercially available equipment.

The storage tests in pure lubricating oil are carried out in accordance with the DIN ISO 1817 standard (DIN ISO 1817: 2016-11). The following elastomer test bodies are exposed to the pure lubricating oil under the following measuring conditions:

FKM: 80 FKM 10061: 168 h / 150 ° C;

85 FKM 245601: 168 h / 150 ° C

NBR: ISO 6072 NBR 1: 1000 h / 100 ° C

The storage tests in oil-water emulsions are carried out based on DIN ISO 1817 (DIN ISO 1817: 2016-11). The test oil is poured into a suitable test vessel (e.g. flat flange beaker with groove 2000 ml DN 120, with flat ground joint cover DN 120) with 5% dist. Water is added (for 1600 ml of oil: 85 ml of water, for 1800 ml of oil: 95 ml of water) and the mixture is stirred until a homogeneous state is achieved. The test specimens are completely immersed in the test oil and arranged so that the distance to the side walls of the test vessel is at least 5 mm, and to the bottom of the vessel and the surface of the test oil is at least 10 mm. After attaching a contact thermometer and a reflux condenser, the test vessel is closed to prevent water loss and the medium is heated with constant stirring. The following elastomer test specimens are exposed to an oil-water emulsion under the following measuring conditions:

FKM: 80 FKM 10061: 336 h / 80 ° C

After the exposure time in the pure lubricating oil or the oil-water emulsion, the specimens are allowed to cool and cleaned. Subsequently, changes in hardness, weight, volume, the tensile strength and / or elongation at break of the elastomers after storage in the lubricant compared to the delivery condition:

- Change in volume, change in weight: Determination is carried out in accordance with DIN ISO 1817 (DIN ISO 1817: 2016-11) Elastomers - Determination of the behavior towards liquids

The change in the volume or weight of the test specimens provides information on the migration of the test liquid into the interior of the material or the dissolution or, if necessary, dissolution of the material.

- Change in Shore A hardness: determination takes place in accordance with DIN ISO 7619-1 (DIN ISO 7619-1: 2012-02) elastomers or thermoplastic elastomers - determination of the penetration depth

- Part 1: Durometer method (Shore hardness)

Hardness is generally the mechanical resistance of the material when a harder test specimen penetrates.

- Change in tensile strength and elongation at break: Determination is carried out in accordance with DIN 53504 (DIN 53504: 2017-03) - Testing of rubber and elastomers - Determination of tensile strength, elongation at break and tension values in the tensile test

The measurement results of the static elastomer storage in pure lubricating oil are given in the following tables 1 to 3: Table 1a (80 FKM 10061/150 ° C / 168 h):

Table 1b (85 FKM 245601/150 ° C / 168 h):

As can be seen from Tables 1a and 1b, the test specimens show only slight changes in volume, weight, or volume after storage in the inventive lubricant compositions of Examples 1, 2 and 3, which each contain an OSP, an antioxidant and a neutral corrosion protection agent Shore A hardness, tensile strength and elongation at break, which means good elastomer compatibility of the lubricant compositions. On the other hand, the

Lubricant composition according to comparative example 1, which contains an OSP and a neutral corrosion protection agent but no antioxidants, does not produce any measurable results, since the lubricant composition begins to decompose under the selected conditions even before the end of the test. The results show a synergistic effect between the components of the lubricants according to the invention.

Table 2 (80 FKM 10061/150 ° C / 168 h):

As can be seen from Table 2, after storage in the lubricant composition according to the invention from Example 1, which contains an OSP, an antioxidant and a neutral corrosion protection agent (TAN <10 mg KOH / g), the test specimen shows significantly lower changes in tensile strength and elongation at break Comparison to storage in the lubricant compositions of the comparative examples, which contain acidic corrosion protection agents in addition to OSP and antioxidants (TAN> 100 mg KOH / g). The results show a synergistic effect between the components of the lubricant according to the invention to the effect that the elastomer compatibility can be improved when a suitable corrosion protection agent is selected.

Table 3 (ISO 6072 NBR 1/100 ° C / 1000 h): As can be seen in Table 3, the test specimens after storage in the lubricant compositions according to the invention from Examples 1 and 4 show comparable changes in terms of weight, volume and Shore A hardness, whereas the inclusion in the lubricant compositions from Example 4 results in a smaller change in tensile strength and elongation at break leads on the test body. The results show that increasing the proportion of OSP in the lubricant composition according to Example 4 leads to a further increase in the compatibility of the lubricant composition with respect to NBR.

The measurement results of the static elastomer incorporation in oil-water emulsions are given in the following table 4: Table 4 (80 FKM 10061 / oil + 5% water; 80 ° C; 336 h)

As can be seen from Table 4, in the case of the lubricant compositions according to the invention of Examples 1, 3 and 5, which contain both an ester and an OSP as base oil components, in contrast to the Comparative Examples 7-11, only slight changes in the weight and volume of the test specimen were observed, which means increased elastomer compatibility. In particular, a comparison of the measurement results with the formulations from Comparative Examples 7, 8 and 9, which only contain esters as the base oil component, with otherwise identical additives (see in particular Example 1 / Comparative Example 8, Example 3 / Comparative Example 9, Example 5 / Comparative Example 7), shows that the absence of an OSP leads to poorer values with regard to the change in weight and in particular change in volume of the test specimen, and thus to reduced elastomer compatibility. The formulations of Comparative Examples 10 and 11 contain a basic corrosion protection agent.

Claims

1. Lubricant composition containing

- an oil-soluble polyalkylene glycol;

an ester compound selected from the group consisting of natural esters and synthetic esters, as well as combinations thereof; and

- An additive mixture comprising an antioxidant and a corrosion protection agent, the corrosion protection agent being selected from neutral alkali and alkaline earth salts of sulfonic acids, carboxylic acids, naphthoic acids, naphthenic acids, benzoic acids and phosphoric acids, as well as their derivatives and combinations thereof.

2. The lubricant composition of claim 1, wherein the neutral alkali and alkaline earth salts are Na, Ca, K and Mg salts.

3. Lubricant composition according to claim 1 or 2, wherein the corrosion protection agent is selected from neutral calcium sulfonates and their derivatives.

4. Lubricant composition according to one of claims 1 to 3, wherein the antioxidant is selected from phenolic antioxidants, aminic antioxidants, phosphites and sulfur-containing compounds, and combinations thereof.

5. Lubricant composition according to one of claims 1 to 4, wherein the antioxidant is selected from phenolic antioxidants, aminic antioxidants, thiocarbamates and dithiocarbamates, and combinations thereof.

6. Lubricant composition according to one of claims 1 to 5, wherein the antioxidant is selected from aminic antioxidants.

7. Lubricant composition according to one of claims 1 to 6, wherein the additive mixture further comprises a non-ferrous metal deactivator selected from triazoles, mercaptothiadiazoles and salicylates, and combinations thereof.

8. The lubricant composition according to claim 7, wherein the non-ferrous metal deactivator is selected from triazoles.

9. Lubricant composition according to one of claims 1 to 8, wherein the ester compound is selected from natural glyceride esters, in particular from the group of sunflower oil, rapeseed oil or rapeseed oil, linseed oil, corn oil, diestel oil, soybean oil, linseed oil, peanut oil, "Lesqueralle" - Oil, palm oil, olive oil, in the monomeric, oligomeric and / or polymerized form; and synthetic esters from the group of polyol esters, polyol complex esters, complex esters of dimer acids, dimer acid esters, aliphatic carboxylic acid and dicarboxylic acid esters, phosphate esters and trimellitic and pyromellitic acid esters and estolides ; as well as combinations thereof.

10. Lubricant composition according to one of claims 1 to 9, wherein the ester compound is selected from polyol esters and polyol complex esters, and combinations thereof.

11. Lubricant composition according to one of claims 1 to 10, wherein the ester compound is selected from neopentyl glycol esters, trimethylolpropane esters, and pentaerythritol esters which are 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, which are 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 are completely esterified or partially esterified in any mixture; as well as combinations thereof.

12. The lubricant composition according to claim 11, wherein the neopentyl glycol esters, the trimethylol propane esters and the pentaerythritol esters each have saturated and / or mono- or polyunsaturated, linear and / or branched ones Monocarboxylic acids of chain length C18-C36 are esterified; and the neopentyl glycol complex esters, the trimethylolpropane complex esters and the pentaerythritol complex esters each with saturated and / or mono- or polyunsaturated, linear and / or branched monocarboxylic acids of chain length C18-C36 and with saturated and / or mono- or polyunsaturated, linear and / or branched dicarboxylic acids of chain length C4-C36 are completely esterified or partially esterified in any mixture.

13. Lubricant composition according to one of claims 1 to 12, wherein the oil-soluble polyalkylene glycol is a copolymer selected from polybutylene oxide-polypropylene oxide copolymers, polybutylene oxide-polyethylene oxide copolymers and polybutylene oxide-polypropylene oxide-polyethylene oxide copolymers, and combinations thereof.

14. Lubricant composition according to one of claims 1 to 13, wherein the oil-soluble polyalkylene glycol is a copolymer selected from polyisobutylene oxide-polyisopropylene oxide copolymers, polyisobutylene oxide-polyethylene oxide copolymers and polyisobutylene oxide-polyisopropylene oxide-polyethylene oxide copolymers, and combinations thereof.

15. Lubricant composition according to one of claims 13 or 14, wherein the oil-soluble polyalkylene glycol copolymer is an alcohol-initiated copolymer, and in particular is a copolymer which has a C10-C20-alkyl radical bonded to at least one terminal end thereof.

16. Lubricant composition according to one of claims 1 to 15, wherein the oil-soluble polyalkylene glycol has a molecular weight M _n of 500 g / mol or more to 1400 g / mol or less.

17. Lubricant composition according to one of claims 1 to 16, wherein the ester compound is contained in an amount of 0.1-85% by weight, based on the total lubricant composition.

18. Lubricant composition according to one of claims 1 to 17, wherein the additive mixture is contained in an amount of 0.1-20% by weight, based on the total lubricant composition.

19. Lubricant composition according to one of claims 1 to 18, wherein the additive mixture further includes one or more additives selected from wear protection agents, friction reducers, high pressure additives, ion complexing agents, solid lubricants, dispersants, pour point and viscosity improvers, UV stabilizers, emulsifiers, color indicators,

Includes slip improvers and defoamers.

20. Use of a lubricant composition according to one of claims 1 to 19 as gear oil, roller bearing oil, hydraulic oil or plain 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 slide, roller or stern tube bearings, chains, ropes, springs, valves and screws in machines, machine components and systems that come into contact with water, as well as in machines and machine elements on land that come into contact with water and / or come into contact with aqueous media.