Grease composition comprising ionic liquid

Abstract

A grease composition comprising: a) 20 to 96 wt%, based on the total weight of the grease composition, of a base oil wherein the base oil comprises at least 50 wt%, based on the total weight of the base oil, of a base oil A wherein the base oil A is an ester and / or a polyglycol; the present invention relates to a grease composition comprising: a) a polyglycol having a carbon group, preferably an unsubstituted ethylene unit in the repeating units, b) 0.5 to 80 wt%, based on the total weight of the grease composition, of an ionic liquid having a bis (fluorosulfonyl) imide as the anion, c) 3 to 35 wt%, based on the total weight of the grease composition, of a thickening agent, and d) 0.5 to 30 wt%, based on the total weight of the grease composition, of a polyglycol having a carbon group as the carbon group and preferably an unsubstituted ethylene unit in the repeating units. The thickener is selected from the group consisting of urea, lithium single soap, metal complex soap of elements of the first and second main groups of the periodic table, in particular lithium complex soap, and mixtures thereof.

Description

Field of the Invention

[0001] The present invention relates to a grease composition containing an ionic liquid and use thereof. Background Art

[0002] It is well known that ionic liquids can be used as additives for lubricants such as greases and oils. This can have a favorable effect on tribologically relevant properties such as friction, wear and electrical conductivity. Ionic liquids with groups containing CFx achieve particularly good results. These groups are usually contained in anions and, as additives to lubricants, improve the heat load capacity and electrical conductivity of the lubricant. Bis(trifluoromethylsulfonyl)imide (BTA), which has very good heat and hydrolysis resistance, is an important representative of these anions.

[0003] However, a disadvantage of compounds containing CFx is that these groups are not biodegradable and ionic liquids containing such groups are persistent.

[0004] A lubricant composition is known from EP 3872154 (A1), which comprises:

[0005] a) lubricants, in particular lubricants containing non-polar base oils,

[0006] b) a first ionic liquid, soluble in polyalphaolefin (PAO), in particular PAO400 / 40 prepared with 1-decene as a monomer component,

[0007] c) The second ionic liquid is insoluble in polyalphaolefin (PAO), in particular PAO400 / 40 prepared with 1-decene as a monomer component.

[0008] The second ionic liquid can be trihexyl (tetradecyl) phosphonium bis (fluorosulfonyl) imide, but is not limited thereto. However, it is known to those skilled in the art that the heat resistance of ionic liquids with bis (fluorosulfonyl) imide (FSI) as anions is significantly lower than that of ionic liquids with groups containing CFx. This is mainly because the FSI anion lacks a carbon-fluorine bond with strong binding force, which has a negative impact on the molecular stability as a whole.

[0009] Another disadvantage of the above lubricant composition is that the use of two different ionic liquids increases the complexity of the preparation process, thereby increasing the preparation cost, and the lubricant composition is limited to non-polar base oil. It is true that non-polar base oil may also contain polar components. However, based on the total weight of the base oil, the polar components are always less than 50wt%.

[0010] EP 2 164 935 B1 describes the use of ionic liquids with fluorine-containing anions in grease compositions to reduce lubricant aging and lower electrical resistance. Summary of the invention

[0011] The object of the present invention is to provide a lubricant composition which can dispense with the use of BTA-containing ionic liquids but still has good tribologically relevant properties in terms of friction, wear and conductivity. In addition, such a lubricant composition should also have sufficient temperature stability, preferably at least 180°C, and can contain a relatively high proportion of polar base oils.

[0012] This object is achieved by a grease composition comprising:

[0013] a) 20 wt% to 96.5 wt% of a base oil, based on the total weight of the grease composition, wherein the base oil comprises at least 50 wt% of a base oil A, based on the total weight of the base oil, wherein the base oil A is an ester and / or a polyglycol, preferably a polyglycol containing unsubstituted ethylene units as carbon groups in the repeating unit.

[0014] b) 0.5 wt % to 80 wt % of an ionic liquid having a bis(fluorosulfonyl)imide anion, based on the total weight of the grease composition,

[0015] c) based on the total weight of the grease composition, 3 to 35 wt% of a thickener selected from urea, lithium soap, metal complex soaps of elements of the first and second main groups of the periodic table, in particular lithium complex soap, and mixtures thereof.

[0016] The present invention has found that the grease composition of the present invention does not require the use of ionic liquids containing BTA, while still achieving tribologically relevant properties related to friction, wear and conductivity. In addition, the grease composition may also contain a relatively high proportion of polar base oil and have sufficient temperature stability, preferably at least 180°C. The high temperature stability of the grease composition of the present invention is unexpected because ionic liquids with bis(fluorosulfonyl)imide anions are known to have only low thermal stability. Without explaining the specific mechanism, it is speculated that the unexpectedly high thermal stability of the bis(fluorosulfonyl)imide anions in the lubricant of the present invention can be attributed to the solubilization of the base oil, which has a stabilizing effect. It is also conceivable that stabilization can be achieved by inhibiting or delaying the autocatalytic effect of the base oil.

[0017] According to the present invention, the grease composition preferably comprises a base oil having a solubility of at least 3 wt % for ionic liquid methyl trioctylammonium bis(fluorosulfonyl)imide at room temperature of 20°C. This solubility indicates the higher polarity of the base oil. In addition, the solubility of base oil A for ionic liquid methyl trioctylammonium bis(fluorosulfonyl)imide at room temperature of 20°C is preferably also at least 3 wt %. The solubility for ionic liquid methyl trioctylammonium bis(fluorosulfonyl)imide is preferably carried out as described in the chapter on test methods.

[0018] The base oil may comprise one or more base oils A and, if necessary, may also comprise a base oil different from the base oil A. However, according to the present invention, the grease composition preferably comprises no further base oils in addition to the base oils mentioned.

[0019] In a preferred embodiment of the present invention, the solubility of the base oil in the ionic liquid methyl trioctylammonium bis(fluorosulfonyl)imide at room temperature of 20° C. is at least 3 wt %, preferably at least 5 wt %, and more preferably at least 10 wt %.

[0020] In another preferred embodiment of the present invention, the solubility of the base oil in the ionic liquid methyl trioctyl ammonium bis(fluorosulfonyl)imide at room temperature of 20°C is at least in the range of 3wt% to 30wt%, and / or at least in the range of 5wt% to 30wt%, and / or at least in the range of 10wt% to 30wt%, and / or at least in the range of 3wt% to 20wt%, and / or at least in the range of 5wt% to 20wt%, and / or at least in the range of 10wt% to 20wt%, and / or at least in the range of 3wt% to 15wt%, and / or at least in the range of 5wt% to 15wt%, and / or at least in the range of 10wt% to 15wt%.

[0021] In a preferred embodiment of the present invention, the solubility of base oil A in ionic liquid methyl trioctylammonium bis(fluorosulfonyl)imide at room temperature of 20°C is at least 3 wt%, preferably at least 5 wt%, more preferably at least 10 wt%.

[0022] In another preferred embodiment of the present invention, the solubility of base oil A in the ionic liquid methyl trioctylammonium bis(fluorosulfonyl)imide at room temperature of 20°C is at least in the range of 3wt% to 99wt%, and / or at least in the range of 5wt% to 99wt%, and / or at least in the range of 10wt% to 99wt%, and / or at least in the range of 3wt% to 80wt%, and / or at least in the range of 5wt% to 80wt%, and / or at least in the range of 10wt% to 80wt%, and / or at least in the range of 3wt% to 15wt%, and / or at least in the range of 5wt% to 15wt%, and / or at least in the range of 10wt% to 15wt%.

[0023] In a preferred embodiment, based on the total weight of the base oil, the proportion of base oil A is 50wt% to 100wt% and / or is greater than 55wt%, for example, 55wt% to 100wt%, and / or is greater than 60wt%, for example, 60wt% to 100wt%, more preferably greater than 70wt%, for example, 70wt% to 100wt%.

[0024] Based on the total weight of the grease composition, the base oil accounts for 20wt% to 96.5wt%, preferably 40wt% to 95%, more preferably 60wt% to 90wt%, more preferably 70wt% to 95wt%, especially 75wt% to 85wt%.

[0025] Based on the total weight of the grease composition, the proportion of base oil A is preferably 10 wt % to 96.5 wt %, more preferably 35 wt % to 95 wt %, more preferably 40 wt % to 90 wt %, especially 35 wt % to 85 wt %.

[0026] In a preferred embodiment, base oil A is an ester and / or a polyglycol, wherein the polyglycol is preferably a polyglycol containing unsubstituted ethylene units as carbon groups in repeating units. Particularly preferred polyglycols are polyalkylene glycols containing unsubstituted ethylene units as carbon groups in repeating units, preferably polyalkylene glycols containing unsubstituted ethylene units and methyl-substituted ethylene units as carbon groups in repeating units. Equally preferred polyglycols are polyalkylene glycols containing unsubstituted ethylene units as carbon groups in repeating units, wherein the weight proportion of unsubstituted ethylene units is preferably at least 20 wt%, such as 20 wt% to 100 wt%, preferably at least 30 wt%, such as 30 wt% to 100 wt%, based on the total weight of the polyglycol.

[0027] In a preferred embodiment, the oxygen / carbon weight ratio of the ester is greater than 0.1, such as 0.1 to 0.35, preferably greater than 0.15 to 0.30, and / or the oxygen / carbon weight ratio of the polyglycol is greater than 0.44, such as 0.44 to 0.70, preferably greater than 0.50, such as 0.50 to 0.68.

[0028] Particularly preferred polyglycols are selected from homopolymers with ethylene oxide as the only monomer and / or copolymers with unsubstituted ethyl groups and 1-methylethyl groups as carbon groups in repeating units, wherein the weight proportion of unsubstituted ethylene units in the copolymer is preferably at least 20 wt%, for example 20 wt% to 90 wt%, preferably at least 30 wt%, for example 30 wt% to 90 wt%, based on the total weight of the polyglycol. The end groups of particularly preferred polyglycols are independent of each other, preferably hydroxyl groups and / or C1-C20 alkanol groups, preferably C1-C6 alkanol groups. The alkanol end groups may be further substituted. In the preparation of the polyglycol, the end groups can be introduced by reacting the monomer ethylene oxide with a monofunctional initiator. The monofunctional initiator is preferably water and alcohols, in particular butanol. Two or more chains of the polyglycol can also be connected via end groups. The connecting end groups are preferably alkyl groups. This can be accomplished with the aid of difunctional or higher functional nucleophilic initiators when preparing the polyglycol with ethylene oxide. Examples of difunctional initiators are diols, in particular 1,2-ethylene glycol.

[0029] Preferred esters are carboxylic acid esters, preferably monoesters, diesters, triesters, tetraesters, pentaesters, polyesters, preferably estolides. Particularly preferred are diesters, triesters, tetraesters, pentaesters, polyesters, estolides and mixtures thereof. Equally preferred carboxylic acid esters are aromatic esters, preferably aromatic C8-C20, preferably C8-C10-, aromatic esters of aliphatic C7 to C22 alcohols present in the form of a dicarboxylic acid, tricarboxylic acid or tetracarboxylic acid and monomer or mixture, and aliphatic esters, preferably aliphatic C4-C22 monocarboxylic acids and / or dicarboxylic acids and the carbon number present in the form of a monomer or mixture being 3 to 22 aliphatic monohydric alcohols, diols, triols, tetraols, pentahydric alcohols, hexahydric alcohols, preferably polyol esters, such as preferred complex esters, aliphatic esters of estolides and mixtures thereof. The carbon number of the acid component and / or alcohol component and / or hydroxycarboxylic acid component in the carboxylic acid ester is preferably C3 to C54 without interfering with each other. Among them, the preferred acid component has a carbon number of C4 to C22, the preferred alcohol component has a carbon number of C3 to C22, and / or the preferred hydroxycarboxylic acid component has a carbon number of C14 to C22. Preferred diesters are diesters whose acid component has less than 36 carbon atoms, preferably 6 to 20 carbon atoms, and more preferably 6 to 12 carbon atoms. The advantage of these esters is that they have good solubility for ionic liquid methyl trioctyl ammonium bis (fluorosulfonyl) imide.

[0030] Estolides are oligomers of oligomeric aliphatic hydroxycarboxylic acids (preferably 12-hydroxystearic acid) or unsaturated carboxylic acids (preferably oleic acid), wherein the terminal carboxylic acid groups are esterified with mono-, di-, tri- and / or tetra-alcohols, preferably with branched mono-, particularly preferably with Guerbet alcohols, and any free hydroxyl groups present can be esterified by reaction with mono- or dicarboxylic acids. Particularly preferred are aliphatic esters of mono- and / or dicarboxylic acids having a carbon number of C3 to C20 (preferably C6 to C20) and mono-, di-, tri-, tetra-, penta- and / or hexa-alcohols having a carbon number of 3 to 22, present as monomers or as a mixture.

[0031] In a particularly preferred embodiment, the ester is selected from the group consisting of aliphatic esters of aliphatic monocarboxylic acids having carbon atoms of C5 to C22 and aliphatic triols, tetraols, hexaols having carbon atoms of C3 to C10, in particular trimethylolpropane, pentaerythritol and / or dipentaerythritol, in the form of monomers or mixtures, and / or aliphatic esters of aliphatic dicarboxylic acids having carbon atoms of C6 to C20 and aliphatic mono- and / or diols having carbon atoms of 6 to 22, in the form of monomers or mixtures, estolides, aromatic tricarboxylic acids and tetracarboxylic acids and aromatic esters of aliphatic C7 to C22 alcohols in the form of monomers or mixtures, and mixtures thereof.

[0032] The base oil also suitable for the present invention comprises base oil A mixed with base oil B. The solubility of base oil B in ionic liquid methyl trioctyl ammonium bis(fluorosulfonyl)imide at room temperature of 20° C. is preferably less than 3 wt %, for example, 01 wt % to 3 wt %, preferably less than 2.5 wt %, for example, 0.01 wt % to 2.5 wt %, more preferably less than 2 wt %, for example, 0.01 wt % to 2 wt %, more preferably less than 1 wt %, for example, 0.01 wt % to 1 wt %.

[0033] In another preferred embodiment, base oil B is a base oil B1 having an oxygen / carbon weight ratio of up to 0.1, such as 0 to 0.1, and / or a base oil B2 having a halogen and / or silicon content of more than 5 wt%, such as 5 wt% to 30 wt%, preferably 10 wt% to 25 wt%, based on the total weight of base oil B2.

[0034] If the base oil comprises base oil A mixed with base oil B, the proportion of base oil A is greater than 50 wt%, for example, 50 to 90 wt%, more preferably greater than 60 wt%, for example, 60 to 85 wt%, and in particular greater than 70 wt%, for example, 70 to 85 wt%, based on the total weight of the base oil.

[0035] Preferred base oils B are selected from the group consisting of: seq.] group I, II, II+, III, IV base oils and the following group V base oils, namely diphenyl ether, alkylated naphthalene, polyisobutylene, silicone oil, polytetrahydrofuran and oxetane polymers, polyalkylene glycols containing ethylene units substituted by aliphatic and / or aromatic alkyl groups, wherein the weight proportion of unsubstituted ethylene units in the polyalkylene glycol is less than 20wt% based on the total weight of the polyalkylene glycol, and aliphatic esters of aliphatic dicarboxylic acids with carbon atoms of C22 to C40, preferably C34 to C38, and aliphatic monohydric alcohols and / or dihydric alcohols with carbon atoms of 6 to 22 in the form of monomers or mixtures, aliphatic esters of aliphatic tricarboxylic acids with carbon atoms of C33 to C60, preferably C50 to C58, and aliphatic monohydric alcohols and / or dihydric alcohols with carbon atoms of 6 to 22 in the form of monomers or mixtures, and mixtures thereof. Particularly preferred base oils are alkylated diphenyl ethers, polyisobutylenes, polyalphaolefins and mixtures thereof. The base oil may also consist of a mixture of the above base oils.

[0036] Based on the total weight of the base oil, the proportion of base oil B (if present) is preferably less than 50wt%, for example 10wt% to 49wt%, more preferably up to 40wt%, for example 10wt% to 40wt%, especially up to 30wt%, for example 10wt% to 30wt%.

[0037] Based on the total weight of the grease composition, the proportion of base oil B (if present) is preferably up to 48wt%, for example 5wt% to 48wt%, more preferably up to 40wt%, for example 10wt% to 40wt%, in particular up to 30wt%, for example 10wt% to 30wt%.

[0038] The grease composition of the present invention preferably has a viscosity of 20 mm at 40°C. 2 / sec to 1500mm 2 / sec, preferably 20mm 2 / sec to 320mm 2 / sec, preferably 25mm 2 / sec to 220mm 2 / sec, preferably 30mm 2 / sec to 150mm 2 Kinematic viscosity is measured according to ASTM D 7042 (Edition 2021.01).

[0039] According to the present invention, based on the total weight of the grease composition, the ionic liquid having a bis(fluorosulfonyl)imide anion accounts for 0.5 wt % to 80 wt %, more preferably 2 wt % to 40 wt %, more preferably 2 wt % to 20 wt %, more preferably 3 wt % to 15 wt %, and especially 5 wt % to 10 wt %.

[0040] In a preferred embodiment, the base oil comprises base oil A and base oil B, and the weight ratio between base oil A and base oil B is at least 50:50, for example, 50:50 to 60:40, more preferably at least 60:40, for example, 60:40 to 70:30, more preferably at least 70:30, for example, 70:30 to 90:10, in particular at least 80:20, for example, 80:20 to 90:10.

[0041] In another preferred embodiment, the base oil comprises base oil A and base oil B, the weight ratio of base oil A to base oil B is 50:50 to 60:40, and based on the total weight of the grease composition, the proportion of the ionic liquid having a bis(fluorosulfonyl)imide (FSI) anion is 0.5 wt % to 10 wt %, preferably 3 wt % to 10 wt %, and / or, the weight ratio of base oil A to base oil B is 60:40 to 70:30, and based on the total weight of the grease composition, the proportion of the ionic liquid having a bis(fluorosulfonyl)imide (FSI) anion is 0.5 wt % to 15 wt %. t%, preferably 3wt% to 15wt%, and / or, the weight ratio between base oil A and base oil B is 70:30 to 90:10, and based on the total weight of the grease composition, the proportion of the ionic liquid having a bis(fluorosulfonyl)imide (FSI) anion is 0.5wt% to 40wt%, preferably 3wt% to 20wt%, and / or, the weight ratio between base oil A and base oil B is 80:20 to 90:10, and based on the total weight of the grease composition, the proportion of the ionic liquid having a bis(fluorosulfonyl)imide (FSI) anion is 0.5wt% to 80wt%.

[0042] In another preferred embodiment of the present invention, the ionic liquid comprises a cation selected from the group consisting of symmetrical and asymmetrical ammonium ions NR1R2R3R4+ and phosphonium ions PR1R2R3R4+. The residues R1 to R4 can be independently branched or unbranched, substituted or unsubstituted C1- to C 24 -alkyl groups, preferably C1- to C 18 -alkyl groups, particularly preferably C6- to C 18 -alkyl group or C6- to C 30 - an aryl group. Among them, preferred substituents are alkoxy, carboxyl, amide, amino, thiocarboxyl, carbamoyl, oxo, thio and / or hydroxyl.

[0043] Preferably, the residues R1 to R4 are selected such that they have in total at least 10 carbon atoms, preferably at least 20 carbon atoms, more preferably at least 25 carbon atoms.

[0044] In a particularly preferred embodiment of the present invention, the ionic liquid comprises one or more cations selected from the group consisting of trihexyltetradecylphosphonium, tributyltetradecylphosphonium, tetraoctylphosphonium, trioctylmethylammonium, tributylmethylphosphonium, tributylphosphonium, and mixtures thereof. Among them, trihexyltetradecylphosphonium, tributyltetradecylphosphonium, tetraoctylphosphonium and trioctylmethylammonium and mixtures thereof are particularly preferred.

[0045] The grease composition of the present invention may also contain a mixture of different ionic liquids, the anions of which are all bis(fluorosulfonyl)imide, but the cations are different. The grease composition of the present invention may also contain other ionic liquids whose anions are not bis(fluorosulfonyl)imide. In this case, the proportion of the other ionic liquids is preferably 0.5wt% to 5wt% based on the total weight of the grease composition.

[0046] However, in a preferred embodiment of the present invention, the grease composition does not contain an ionic liquid that is not a bis(fluorosulfonyl)imide anion. This is advantageous because the use of multiple ionic liquids increases the complexity of the preparation process and thus increases the preparation cost. Further preferably, the grease composition does not contain an ionic liquid with a bis(trifluoromethylsulfonyl)imide (BTA) anion. This is advantageous from a toxicological point of view. In another embodiment of the present invention, the grease composition does not contain an ionic liquid whose anion does not have a bis(fluorosulfonyl)imide anion, or contains an ionic liquid with a maximum of 0.5 wt% based on the total weight of the grease composition. Further preferably, the grease composition does not contain an ionic liquid containing a perfluoroalkyl group, or, based on the total weight of the grease composition, the grease composition contains an ionic liquid containing a perfluoroalkyl group with a maximum of 0.5 wt%. From a toxicological point of view, this is advantageous.

[0047] In a particularly preferred embodiment of the present invention, the ionic liquid whose anion is bis(fluorosulfonyl)imide is selected from the group consisting of:

[0048] P666(14)fsi, trihexyl(tetradecyl)phosphonium bis(fluorosulfonyl)imide

[0049]

[0050] N1888 fsi, methyl trioctylammonium bis(fluorosulfonyl)imide

[0051] P444(14)fsi, tributyltetradecylphosphonium bis(fluorosulfonyl)imide

[0052] P8888 fsi, tetraoctylphosphonium bis(fluorosulfonyl)imide

[0053]

[0054] and mixtures thereof.

[0055] The use of ionic liquids in lubricant compositions designed as grease compositions is particularly advantageous, since the positive effect of the ionic liquid fsi on service life is particularly pronounced in greases, since the amount of grease present at the lubrication point is generally lower than that of lubricating oil.

[0056] Preferably, based on the total weight of the grease composition, the thickener contained in the grease composition accounts for 4 wt % to 30 wt %, especially 6 wt % to 20 wt %.

[0057] The worked cone penetration (in 1 / 10 mm) of the grease composition designed as a lubricating grease is preferably between 400 and 200, more preferably between 330 and 220, and more preferably between 300 and 250. The worked cone penetration is measured according to DIN ISO 2137 (2016.12 edition).

[0058] According to the present invention, the thickener is selected from the group consisting of urea, lithium soap, metal complex soaps of elements of the first and second main groups of the periodic table, in particular lithium complex soap, and mixtures thereof. Urea refers to the reaction product of monofunctional, difunctional, trifunctional and higher functional organic isocyanates and / or mixtures thereof with monofunctional, difunctional, trifunctional or higher functional aliphatic and / or aromatic organic amines.

[0059] The advantage of urea is that it can be used at higher service temperatures, so when used in combination with an ionic liquid having an fsi anion, it can provide a particularly long service life for the grease. Preferred ureas are the reaction products of diisocyanates with amines or diamines of the general formula (H2N)xR, the diisocyanates preferably being 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane, 4,4'-diisocyanatodiphenyl, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 4,4'-diisocyanato-3,3'-dimethylphenylmethane, which can be used alone or in combination, wherein x=1 or 2, and R is an aryl, alkyl, cycloalkyl or alkylene residue having 2 to 22 carbon atoms.

[0060] In a particularly preferred embodiment, the urea is a diurea comprising aliphatic, cycloaliphatic / aliphatic and / or cycloaliphatic urea.

[0061] In a particularly preferred embodiment, the urea is a diurea expressed by formula A

[0062]

[0063] wherein R2 is a divalent C6-15 aromatic hydrocarbon residue; R1 and R3 are independently a C6-20 cycloalkyl residue, in particular a cyclohexyl residue, or a straight-chain or branched C8-20 alkyl residue.

[0064] Bisurea compounds which can be preferably used according to the invention are described in DE 11 2012 001 102 A1.

[0065] Preferred diurea compounds are selected from:

[0066] Aliphatic urea of ​​formula A:

[0067]

[0068] Aliphatic urea of ​​formula B:

[0069]

[0070] Aliphatic urea of ​​formula C:

[0071]

[0072] Cycloaliphatic / aliphatic urea of ​​formula D:

[0073]

[0074] Cycloaliphatic / aliphatic urea of ​​formula E:

[0075]

[0076] Cycloaliphatic urea of ​​formula F:

[0077]

[0078] and mixtures thereof.

[0079] In the ureas of Formulae A to E, the alkyl groups are unbranched.

[0080] In another embodiment, the thickener is selected from lithium monosoap, metal complex soaps of elements of the first and second main groups of the periodic table, in particular lithium complex soap, and mixtures thereof.

[0081] The lithium complex soap is preferably a lithium complex soap made from the following substances: C4-C36 dicarboxylic acids, preferably azelaic acid, sebacic acid, suberic acid, terephthalic acid, dodecanedioic acid, and / or high-functionality carboxylic acids with 3 or more, preferably 3 to 4 carboxylic acid groups, wherein the number of carbon groups can be 6 to 60, such as preferably citric acid and trimer acid, and / or ester compounds, in particular methyl esters and / or triglycerides of one or more of the above acids, respectively in combination with one or more monocarboxylic acids, preferably in combination with one or more C4-C24 monocarboxylic acids, preferably stearic acid, hydroxystearic acid, in particular 12-hydroxystearic acid, palmitic acid, oleic acid, salicylic acid, ester compounds, in particular methyl esters and / or triglycerides of one or more of the above acids, and / or in combination with sebacic acid monostearate and / or terephthalic acid monostearate.

[0082] In another embodiment, the grease composition comprises 20 wt % to 92.5 wt % of a base oil based on the total weight of the grease composition and 4 wt % to 20 wt % of an additional thickener based on the total weight of the grease composition, wherein the additional thickener is preferably selected from aluminum complex soap, bentonite, sulfonate, silicate, polyimide and mixtures thereof.

[0083] The grease composition may also contain inorganic and / or organic solid lubricants. Preferred solid lubricants are selected from the group consisting of polytetrafluoroethylene (PTFE), molybdenum disulfide, graphite, graphene, boron nitride (hexagonal), tin (IV) sulfide, zinc (II) sulfide, tungsten disulfide, metal sulfides, phosphates (preferably calcium phosphate), carbonates (preferably calcium carbonate), metal oxides (preferably amorphous silica), silicates and layered silicates, talc, mica, and mixtures thereof.

[0084] Particularly preferred solid lubricants are selected from the group consisting of molybdenum disulfide, graphite, graphene, boron nitride (hexagonal), tin (IV) sulfide, zinc (II) sulfide, tungsten disulfide, metal sulfides, phosphates (preferably calcium phosphate), carbonates (preferably calcium carbonate), metal oxides (preferably amorphous silica), silicates and layered silicates, talc, mica, and mixtures thereof.

[0085] If a solid lubricant is present, the solid lubricant preferably accounts for 0.5 wt % to 23 wt %, more preferably 0.5 wt % to 20 wt %, and especially 0.5 wt % to 18 wt % of the grease composition of the present invention, based on the total weight of the grease composition.

[0086] In addition, the grease composition may also contain additives such as those having anti-corrosion, anti-oxidation (antioxidants) and anti-metal effects, such as chelates, free radical scavengers, UV stabilizers, reactive layer formers, viscosity enhancers, pour point depressants, adhesion enhancers, and / or additives for reducing the amount of oil separation in the grease.

[0087] The additives preferably account for 0.5 to 23 wt %, more preferably 0.5 to 20 wt %, more preferably 1 to 18 wt %, and in particular 1.5 to 12 wt %, based on the total weight of the grease composition. Additives are preferably used in the form of phosphorus-, sulfur-, nitrogen- and / or oxygen-containing compounds, polymers and / or mixtures thereof. Particularly preferred additives are aromatic amines, phenols, in particular alkylated phenols, triazoles, such as benzotriazole, tolyltriazole, esters, in particular sulphurised fatty acid esters, mono- or diesters of glycerol, sorbitol esters, thiadiazoles, dithiocarbamates, in particular molybdenum dithiocarbamates, phosphates, in particular thiophosphates, oligophosphates, oligothiophosphates, dithiophosphates, zinc dialkyldithiophosphates, molybdenum dithiophosphates, phosphoamines, trialkylphosphates, triarylphosphates, phosphites, metal salts, carboxylic acids, polymers, in particular polymethacrylates, olefin copolymers and / or mixtures thereof.

[0088] Very preferred additives are aromatic amines, alkylated phenols, thiadiazoles, dithiocarbamates, triarylphosphates, phosphoamines, benzotriazoles and / or mixtures thereof.

[0089] Particularly preferred additives are aromatic amines, since it has surprisingly been found that when aromatic amines are used, ionic liquids are able to delay the onset of oxidation particularly strongly.

[0090] According to the present invention, preferred aromatic amines are styrenated diphenylamine, phenyl-α-naphthylamine, phenyl-β-naphthylamine, octylated and / or butylated diphenylamine, in particular p,p'-dioctyldiphenylamine, nonylated diphenylamine. Therefore, in a particularly preferred embodiment of the present invention, the grease composition contains diphenylamine, in particular p,p'-dioctyldiphenylamine, as an antioxidant.

[0091] In another preferred embodiment of the present invention, based on the total weight of the grease composition, the additive in the grease composition accounts for 0.5wt% to 23wt%, more preferably 0.5wt% to 20wt%, especially 0.5wt% to 10wt%.

[0092] Preferably, the grease composition is characterized in that the lower service temperature determined according to IP 186 (2015 edition) does not exceed -30°C, for example, from -60°C to -30°C, preferably does not exceed -40°C, for example, from -60°C to -40°C, and / or the higher service temperature determined according to DIN 51821 1+2 (2016, 7 edition) is preferably at least +160°C, for example, from 160°C to 220°C, preferably at least +180°C, for example, from 180°C to 220°C.

[0093] A further subject matter of the present invention comprises the use of the grease composition according to the invention for lubricating drive elements, preferably for lubricating rolling bearings, gearboxes, plain bearings, actuators and / or chains.

[0094] The drive elements at which the electrical potential is present are preferably rolling bearings, gearboxes, plain bearings, actuators and / or chains.

[0095] Further preferred drive elements are rolling bearings, gearboxes, sliding bearings, transmissions and / or chains arranged in plants and machines for producing and conveying food, wind power plants, vehicles (preferably cars, in particular hybrid and electric cars), rail vehicles, industrial plants, industrial robots and / or ships.

[0096] Particularly preferably, the drive element is selected from pulley bearings, fan bearings, vacuum pump bearings, rolling bearings of electric motors (in particular electric motors of hybrid vehicles and electric vehicles), generators (in particular generators of electric vehicles and rail vehicles), wind power equipment, industrial motors, vehicle auxiliary devices and / or vehicle joints.

[0097] Particularly preferably, the grease composition is used for lubricating rolling bearings of electric motors of hybrid and / or electric vehicles.

[0098] Advantageously, the grease compositions of the invention exhibit a combination of properties which are particularly suitable for these applications. Particularly advantageous is the very good temperature stability combined with the electrical conductivity.

[0099] Another subject of the present invention includes the use of the lubricating ester composition for lubricating drive elements, preferably for lubricating rolling bearings, wherein the lower service temperature is not more than -30°C, for example -60°C to -30°C, preferably not more than -40°C, for example -60°C to -30°C, measured according to IP 186 (2015 edition), and / or, according to DIN 51821 1+2 (2016, 7 edition), the higher service temperature is preferably at least +160°C, for example 160°C to 220°C, more preferably at least +180°C, for example 180°C to 220°C.

[0100] The invention will be explained in detail below with reference to a number of non-limiting examples.

[0101] Example 1

[0102] TGA measurements were performed on ionic liquids trihexyl(tetradecyl)phosphonium bis(fluorosulfonyl)imide (P666(14)fsi) and trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide (P666(14)bta), and the obtained values ​​were compared with each other.

[0103]

[0104] Table 2: TGA evaporation losses under air and N2 conditions

[0105] As expected, TGA measurements showed that P666(14)bta has a better temperature stability compared to P666(14)fsi. P666(14)bta has lower evaporation loss values ​​when measured in both air and nitrogen. The better temperature stability of bta can be explained by the strong carbon-fluorine bonds in the anion.

[0106] Example 2

[0107] DSC measurements were performed on the ionic liquids trihexyl(tetradecyl)phosphonium bis(fluorosulfonyl)imide (P666(14)fsi) and trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide (P666(14)bta).

[0108] Figure 1 The DSC measurement results performed under an O2 atmosphere are shown. Figure 2 Shown are the results of DSC measurements performed under a N2 atmosphere.

[0109] exist Figure 1 As can be seen in Figure 2, P666(14)fsi starts earlier than P666(14)bta and is therefore less stable.

[0110] like Figure 2 As shown in Figure 2, P666(14)fsi undergoes a significant exothermic reaction around 270°C, while P666(14)bta does not. Both studies confirm that ionic liquids with fsi anions have lower heat resistance in pure substances.

[0111] Example 3

[0112] To determine the evaporation loss, trihexyl(tetradecyl)phosphonium bis(fluorosulfonyl)imide (P666(14)fsi) and trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide (P666(14)bta) were placed in cylindrical threaded glassware (bottom area 1.5 cm 2 , height 5cm). 200mg of each ionic liquid was accurately weighed. At two test temperatures, a glassware without a ball and a glassware with a ball (100Cr6 steel ball in accordance with DIN 51350-1 (2015-03 edition)) were used respectively. This is to test whether there is a reaction between the spherical metal and the ionic liquid in the glassware.

[0113]

[0114] Table 3: Values ​​at 150°C

[0115]

[0116] Table 4: Values ​​at 180°C

[0117] At a test temperature of 150 °C, there are differences in the evaporation losses of the two ionic liquids in the pure substances. For the sample without balls, the evaporation losses of P666(14)bta continue to increase during the measurement. In contrast, an overall weight increase can be observed in the values ​​of the fsi sample. In the presence of steel balls, the evaporation losses of P666(14)fsi are lower than those of P666(14)bta. In the presence of balls, the overall evaporation loss values ​​of both substances are significantly higher. However, after the initial increase, the values ​​of P666(14)fsi decrease again at the end.

[0118] The evaporation losses of both substances at 180 °C are naturally higher than those at 150 °C. Unlike the case at lower test temperatures, the values ​​of P666(14)fsi do not change significantly. However, at the end of the test, its value is still higher than that of P666(14)bta. In summary, the observed values ​​can be understood as follows: in addition to the decomposition with a certain mass loss, phenomena such as water absorption / release, steel ball corrosion and catalytic decomposition also play a role. At 180 °C, the tests on the pure substances showed that the tolerance of ionic liquids containing fsi is lower than that of ionic liquids containing bta.

[0119] Example 4

[0120] Two grease compositions according to the invention and a comparative grease were prepared using base grease A.

[0121] Basic Grease AThe base oil is composed of 85 wt% trimellitate (containing C9-C11 alcohol (TMSE-A), oxygen / carbon ratio is 0.20, and the base oil viscosity at 40°C is about 72 mm 2 / sec) and 11wt% urea thickener (composed of the reaction product of a mixture of aliphatic saturated amines, aliphatic unsaturated amines and aromatic amines with MDI (4,4'-diisocyanato diphenylmethane) and TDI (a mixture of 2,4-diisocyanato toluene and 2,6-diisocyanato toluene, with a molar ratio of about 4:1)). The additives used are 0.5wt% p,p'-dioctyl diphenylamine and 3.5wt% other additives (anti-corrosion, anti-wear).

[0122] Add 5wt% P666(14)fsi( Grease 1 of the present invention ) or 5wt% P666(14)bta( Comparison grease 2 ), and use a three-roll mill to homogenize the mixture. Grease 3 of the present invention 5 wt% N1888 fsi was used in the MgSO4 and introduced in the same manner.

[0123] Compared to base grease A, the specific resistivity is reduced by about 10 to the power of 3. Compared to comparative grease 2, which contains an ionic liquid not according to the invention, the service life of grease 1 according to the invention at 180° C. is surprisingly improved by about 50%. The grease according to the invention also meets the service life requirements of DIN 51821 1+2 at 200° C.

[0124]

[0125]

[0126] The service life test results conducted at 200°C show that the service life of the grease 1 of the present invention is significantly increased, more than 2.5 times the L 50 value. Compared with the base grease A, the service life of the grease 3 of the present invention is also extended by 50%.

[0127] Example 5

[0128] Using base grease B, a number of grease compositions according to the invention and a comparative grease were prepared.

[0129] Base Grease B It is composed of:

[0130] 84.5wt% of trimellitate (containing linear C8 and C10 alkyl groups (TMSE-B) in a molar ratio of about 1:1, with an oxygen / carbon ratio of 0.22), 13.5wt% of urea thickener (formed by the reaction of MDI (4,4'-diisocyanatodiphenylmethane) and octylamine in a molar ratio of 1.2), 1wt% of p,p'-dioctyldiphenylamine, and 1wt% of calcium sulfonate anticorrosive additive.

[0131]

[0132] Compared to base grease B (comparative grease), inventive grease 6 has a service life extended by about 50% while maintaining a very steep failure curve (high beta value). Inventive grease 7 has a service life extended by about 40%.

[0133] All greases according to the invention meet the requirements of DIN 51821 1+2 at 200° C., since the L 50 values ​​are above 100 h.

[0134] This allows the resistance to be reduced while maintaining a higher operating temperature of 200°C (see table below).

[0135]

[0136] The addition of ionic liquid P666(14)fsi significantly reduced the specific resistivity, while the working penetration changed little, indicating that the thickening effect was not disturbed by the ionic liquid.

[0137] Example 6

[0138] The specific resistivity of mixtures of P666(14)fsi or P666(14)bta in polyglycol was measured.

[0139] The polyglycol A used is a polyglycol having a kinematic viscosity of 220 mm 2 / sec polyglycol. It is a random copolymer of ethylene oxide and propylene oxide in a molar ratio of 1:1, with ethylene glycol as the initiator. The oxygen / carbon ratio is 0.53.

[0140]

[0141]

[0142] The table shows that the specific resistivity of the lubricant composition containing P666(14)fsi is lower than that of P666(14)bta. From this, it can be inferred that the specific resistivity of the grease composition containing the above-mentioned base oil A will also be reduced by adding P666(14)fsi.

[0143] This is unexpected because, as shown in the table below, the viscosity of P666(14)fsi is higher than the viscosity of P666(14)bta.

[0144]

[0145] This suggests that in the case of fsi, the ion pairs are actually more strongly bound to each other, i.e. less mobile, and should therefore exhibit weaker conductivity. However, as shown above, this is surprisingly not the case.

[0146] Example 7

[0147] The effect of N1888 fsi on the thermal oxidation resistance of ester oil was studied.

[0148] The base oil used is trimellitate B (a trimellitate containing linear C8 and C10 alkyl groups in a molar ratio of about 1:1), and the amine antioxidant (amine AO) used is p,p'-dioctyldiphenylamine. Trimellitate B is a base oil A.

[0149]

[0150]

[0151]

[0152] The shear viscosity is determined according to DIN 53019-1.3 at 25°C and a shear rate of 300 1 / s. An open dish test is performed using an aluminum evaporating dish with a diameter of 50 mm. Weighing 5 g + / - 0.1 g. The measurement is carried out in a circulating air oven. The measuring time is 24 / 48 / 72 hours. The evaporation loss is determined each time and the shear viscosity is measured.

[0153] Oil 2, Oil 3, Oil 4, Oil 5 and Oil 6 represent lubricant compositions that can be used in combination with a thickener to obtain the grease composition of the present invention.

[0154] Comparison of samples containing only P666(14)fsi (Oil 6 and Oil 5) with samples containing only amine antioxidants (Oil 1 and Oil 7) showed that the ionic liquid delayed the onset of oxidation to a greater extent.

[0155] The pattern of combining the aminic antioxidant p,p'-dioctyldiphenylamine with P666(14)fsi shows a strong positive influence both on the evaporation losses in the TGA up to 300 °C, on the onset and onset of oxidation in the DSC, and on the evaporation values ​​in the open dish test (see, for example, the evaporation values ​​after 24 h).

[0156] Example 8

[0157] The solubility of N1888fsi in base oils containing base oils of different polarities was tested. The results are shown in the following table.

[0158]

[0159] The base oil mixture described here is not suitable for preparing the grease composition of the present invention because the proportion of base oil A is too low, resulting in too low solubility of N1888fsi.

[0160]

[0161] The base oil mixtures described herein are suitable for preparing the grease compositions of the present invention because a sufficient proportion of base oil A is present so that the solubility of N1888fsi is sufficient.

[0162]

[0163] The base oil mixtures described herein are suitable for preparing the grease compositions of the present invention because a sufficient proportion of base oil A is present so that the solubility of N1888fsi is sufficient.

[0164]

[0165]

[0166] The base oils described herein are suitable for preparing the grease compositions of the present invention because a sufficient proportion of base oil A is present so that the solubility of N1888fsi is very good.

[0167] These examples show that the ionic liquid N1888fsi can be mixed with trimellitic acid esters over a wide concentration range.

[0168]

[0169] The base oils described here are not suitable for preparing the grease composition of the present invention, since there is no presence of any proportion of base oil A and therefore the solubility of N1888fsi is insufficient.

[0170]

[0171]

[0172] The base oil mixtures described herein are suitable for preparing the grease compositions of the present invention because a sufficient proportion of base oil A is present so that the solubility of N1888fsi is sufficient.

[0173]

[0174] The base oils described here are not suitable for preparing the grease composition of the present invention, since there is no presence of any proportion of base oil A and therefore the solubility of N1888fsi is insufficient.

[0175]

[0176] The base oils described herein are suitable for preparing the grease compositions of the present invention since only base oil A is present and therefore the solubility of N1888fsi is sufficient.

[0177] It is shown that N1888fsi is easily soluble in base oils with a polar base oil content of more than 50 wt%, and can even be dissolved in large quantities. The polar base oil is selected from esters and polyalkylene glycols prepared using ethylene oxide as a component of the reaction mixture.

[0178] Example 9: Preparation of base grease C and preparation of a non-inventive grease 9 based thereon:

[0179]

[0180] Base Grease C is NLGI grade 1. The kinematic viscosity of the base oil at 40°C is 130 mm 2 / sec, a non-polar mixture of mineral oil / PAO. The oxygen / carbon ratio is close to 0. The thickener is a mixture of urea / calcium complex soap. It also contains the usual additives for oxidation stability, improved load-bearing capacity and corrosion protection. The addition of ionic liquids does not extend the service life and may even reduce the L50 value. It has been shown that the use of ionic liquids in greases with non-polar base oils (mineral oil and PAO) does not bring any improvement.

[0181] Example 10

[0182] A grease D having the following composition was prepared:

[0183] 41wt% trimellitate A, containing C9-C11, V 40 about 72mm 2 / sec (oxygen / carbon ratio is 0.20)

[0184] 17wt% PIB, Mn is about 1300g / mol, measured by GPC (oxygen / carbon ratio is 0.0)

[0185] 20wt% alkylated diphenyl ether, V40 is about 100mm 2 / sec (oxygen / carbon ratio is 0.04)

[0186] 13wt% azelaic acid / 12-hydroxystearate lithium composite thickener

[0187] 4wt% amine antioxidant

[0188] 5wt% composite additive for corrosion protection, AW and EP

[0189] The weight proportion of trimellitate A in the total amount of the base oil is 52.6 wt%.

[0190]

[0191]

[0192] The composition of the present invention shows advantages in reducing specific resistance, low temperature performance (flow pressure) and avoiding hardening when stored at 180°C (no increase in dynamic viscosity).

[0193] Example 11: Solubility study of N8881 fsi in estolide-based oil

[0194]

[0195] N8881 FSI is soluble in estolide-based oil within the concentration range studied. The specific resistivity decreases with increasing ionic liquid content.

[0196] Test result evaluation

[0197] Overall, it can be demonstrated that grease compositions containing ionic liquids with FSI anions have performance values ​​in the range of products with added BTA-based ionic liquids. Therefore, FSI-based ionic liquids can be a good alternative to BTA-containing ionic liquids. In addition, FSI-based additives have the advantage of not containing persistent CFx groups compared to BTA-containing additives.

[0198] In tests conducted on pure P666(14)fsi, as expected, the results showed that it was less thermally stable than P666(14)bta. This is mainly due to the lack of strong carbon-fluorine bonds in the anion, which has an overall impact on the stability of the molecule.

[0199] Surprisingly, the performance differences between the two ionic liquids became significantly smaller when they were used as grease additives. The test property values ​​showed that P666(14)FSI performed very similarly to P666(14)BTA in the observed grease systems. The use of FSI materials as additives met the requirements in terms of high and low temperature properties and electrical conductivity over the observed temperature range.

[0200] Furthermore, the grease composition of the invention also meets the requirements with regard to corrosion stability.

[0201] In conclusion, it is shown that grease compositions comprising FSI-based ionic liquids can be a good alternative to grease compositions having BTA-containing ionic liquids in terms of performance. In addition, the grease compositions of the present invention do not contain persistent CFx groups and are therefore biodegradable.

[0202] Test Method

[0203] Unless otherwise stated, kinematic viscosity at 40°C and 100°C, viscosity index, and density at 40°C and 100°C shall be determined using a Stabinger viscometer conforming to ASTM D 7042 (Edition 2021.01).

[0204] Determination of Carbon Content: Carbon content was determined using ASTM D 5291:2021.

[0205] The oxygen content was measured using JPI-5S-68-11.

[0206] The oxygen / carbon weight ratio can be obtained by dividing the oxygen mass fraction (wt %) determined according to JPI-5S-68-11 by the carbon mass fraction (wt %) determined according to ASTM D 5291:2021.

[0207] To determine the solubility of the ionic liquid N1888 fsi in a base oil or base stock, the base oil or base oils constituting the base oil are placed in a beaker and the corresponding concentration of N1888 fsi is added. The mixture is stirred at 60 ° C for 10 minutes using a magnetic stirrer. After cooling to room temperature, the mixture is visually inspected and the electrical resistance is determined. If the turbidity value obtained by the turbidity measurement at 25 ° C according to DIN EN ISO 7027-1:2016-11 is more than 1 FNU higher than the turbidity value when the pure base oil or base oil is used, N1888 fsi is insoluble in the base oil or base oil at a certain concentration. If two or more phases are formed at a certain concentration, N1888 fsi is also insoluble in the base oil or base oil. If the turbidity value obtained in accordance with DIN EN ISO 7027-1:2016-11 at 25°C is at most 1 FNU higher than the turbidity value when using pure base oil or base stock, N1888fsi is soluble in the base oil or base stock in a certain concentration.

Claims

1. A grease composition comprising: a) 20 wt% to 96.5 wt% of a base oil, based on the total weight of the grease composition, wherein the base oil comprises at least 50 wt% of a base oil A, based on the total weight of the base oil, wherein the base oil A is an ester and / or a polyglycol, preferably a polyglycol comprising unsubstituted ethylene units as carbon groups in the repeating units, b) based on the total weight of the grease composition, 0.5 wt% to 80 wt% of an ionic liquid whose anion is bis(fluorosulfonyl)imide, c) based on the total weight of the grease composition, 3 wt% to 35 wt% of a thickener, the thickener being selected from urea, lithium soap, metal complex soaps of elements of the first and second main groups of the periodic table, in particular lithium complex soap, and mixtures thereof.

2. The grease composition according to claim 1, characterized in that The solubility of the base oil in ionic liquid methyl trioctylammonium bis(fluorosulfonyl)imide at room temperature of 20°C is at least 3 wt %, and / or the solubility of the base oil A in ionic liquid methyl trioctylammonium bis(fluorosulfonyl)imide at room temperature of 20°C is at least 3 wt %.

3. The grease composition according to claim 1 or 2, characterized in that: Based on the total weight of the base oil, the base oil A accounts for 50wt% to 100wt% and / or is greater than 55wt%, for example, 55wt% to 100wt%, and / or is greater than 60wt%, for example, 60wt% to 100wt%, more preferably greater than 70wt%, for example, 70wt% to 100wt%.

4. Grease composition according to one or more of the preceding claims, characterized in that Based on the total weight of the grease composition, the base oil accounts for 40wt% to 95wt%, more preferably 60wt% to 90wt%, more preferably 70wt% to 95wt%, especially 75wt% to 85wt%.

5. Grease composition according to one or more of the preceding claims, characterized in that Based on the total weight of the grease composition, the base oil A accounts for 10wt% to 96.5wt%, more preferably 35wt% to 95wt%, more preferably 40wt% to 90wt%, especially 35wt% to 85wt%.

6. Grease composition according to one or more of the preceding claims, characterized in that The oxygen / carbon weight ratio of the ester is greater than 0.1, such as 0.2 to 0.35, and / or the oxygen / carbon weight ratio of the polyglycol is greater than 0.44, such as 0.44 to 0.

70.

7. Grease composition according to one or more of the preceding claims, characterized in that The ethylene glycol is selected from homopolymers with ethylene oxide as the only monomer and / or copolymers with unsubstituted ethyl groups and 1-methylethyl groups as carbon groups in repeating units, wherein the weight proportion of unsubstituted ethylene units in the copolymer is preferably at least 20wt%, such as 20wt% to 90wt%, and preferably at least 30wt%, such as 30wt% to 90wt%, based on the total weight of the polyglycol, wherein the end groups of the polyglycol are independent of each other, and are preferably hydroxyl groups and / or C1-C20 alkoxide groups.

8. Grease composition according to one or more of the preceding claims, characterized in that The esters are selected from carboxylic acid esters, preferably monoesters, diesters, triesters, tetraesters, pentaesters, polyesters, preferably estolides, and mixtures thereof.

9. Grease composition according to one or more of the preceding claims, characterized in that The esters are selected from the group consisting of aliphatic esters of aliphatic monocarboxylic acids having carbon atoms of C5 to C22 and aliphatic triols, tetraols, hexaols having carbon atoms of C3 to C10, in particular trimethylolpropane, pentaerythritol and / or dipentaerythritol, in the form of monomers or mixtures, and / or aliphatic esters of aliphatic dicarboxylic acids having carbon atoms of C6 to C20 and aliphatic monools and / or diols having carbon atoms of 6 to 22, in the form of monomers or mixtures, estolides, and aromatic esters of aromatic tricarboxylic acids and tetracarboxylic acids and aliphatic C7 to C22 alcohols in the form of monomers or mixtures, and mixtures thereof.

10. Grease composition according to one or more of the preceding claims, characterized in that The base oil comprises a base oil A mixed with a base oil B, wherein the solubility of the base oil B in the ionic liquid methyl trioctylammonium bis(fluorosulfonyl)imide at room temperature of 20° C. is less than 3 wt %.

11. The grease composition according to claim 10, characterized in that The base oil B is a base oil B1, whose oxygen / carbon weight ratio is at most 0.1, preferably 0 to 0.1, and / or the base oil B is a base oil B2, whose halogen content and / or silicon content exceeds 5 wt% based on the total weight of the base oil B2.

12. The grease composition according to claim 10 or 11, characterized in that: The base oil B is selected from the group consisting of the following substances: according to the American Petroleum Institute (API) [NLGI Spokesman, N. Samman, Volume 70, Number 11, p. 14 et seq.] group I, II, II+, III, IV base oils and the following group V base oils, namely diphenyl ether, alkylated naphthalene, polyisobutylene, silicone oil, polytetrahydrofuran and oxetane polymers, polyalkylene glycols containing alkylene units substituted by aliphatic and / or aromatic alkyl groups, wherein the weight proportion of unsubstituted alkylene units in the polyalkylene glycol is less than 20wt% based on the total weight of the polyalkylene glycol, and aliphatic esters of aliphatic dicarboxylic acids with carbon atoms of C22 to C40, preferably C34 to C38, and aliphatic monohydric alcohols and / or dihydric alcohols with carbon atoms of 6 to 22 in the form of monomers or mixtures, aliphatic esters of aliphatic tricarboxylic acids with carbon atoms of C33 to C60, preferably C50 to C58, and aliphatic monohydric alcohols and / or dihydric alcohols with carbon atoms of 6 to 22 in the form of monomers or mixtures, and mixtures thereof.

13. The grease composition according to one or more of claims 10 to 12, characterized in that Based on the total weight of the grease composition, the proportion of the base oil B is up to 48wt%, for example 5wt% to 48wt%, more preferably up to 40wt%, for example 10wt% to 40wt%, in particular up to 30wt%, for example 10wt% to 30wt%, and / or the weight ratio between the base oil A and the base oil B is at least 50:50, particularly preferably at least 60:40, more preferably at least 70:30, in particular at least 80:

20.

14. Grease composition according to one or more of claims 10 to 13, characterized in that The weight ratio of the base oil A to the base oil B is 50:50 to 60:40, and based on the total weight of the grease composition, the proportion of the ionic liquid whose anion is bis(fluorosulfonyl)imide is 0.5wt% to 10wt%, and / or the weight ratio of the base oil A to the base oil B is 60:40 to 70:30, and based on the total weight of the grease composition, the proportion of the ionic liquid whose anion is bis(fluorosulfonyl)imide is 0.5wt% to 15wt%, and / or, the weight ratio of the base oil A to the base oil B is 70:30 to 90:10, and based on the total weight of the grease composition, the proportion of the ionic liquid whose anion is bis(fluorosulfonyl)imide is 0.5wt% to 40wt%, and / or, the weight ratio of the base oil A to the base oil B is 80:20 to 90:10, and based on the total weight of the grease composition, the proportion of the ionic liquid whose anion is bis(fluorosulfonyl)imide is 0.5wt% to 80wt%.

15. Grease composition according to one or more of the preceding claims, characterized in that The kinematic viscosity at 40°C is 20 mm 2 / sec to 1500mm 2 / sec, preferably 20mm 2 / sec to 320mm 2 / sec.

16. Grease composition according to one or more of the preceding claims, characterized in that The ionic liquid comprises a cation selected from the group consisting of symmetrical and asymmetrical ammonium ions NR1R2R3R4+ and phosphonium ions PR1R2R3R4+, wherein the residues R1 to R4 can be independently branched or unbranched, substituted or unsubstituted C1- to C 24 -alkyl groups, preferably C1- to C 18 -alkyl groups, particularly preferably C6- to C 18 -alkyl group or C6- to C 30 - an aryl group.

17. Lubricating grease composition according to one or more of the preceding claims, characterized in that The grease composition does not contain an ionic liquid having an anion other than bis(fluorosulfonyl)imide, or the grease composition contains up to 0.5 wt% of an ionic liquid having an anion other than bis(fluorosulfonyl)imide, based on the total weight of the grease composition.

18. Grease composition according to one or more of the preceding claims, characterized in that The grease composition does not contain an ionic liquid containing a perfluoroalkyl group, or the grease composition contains an ionic liquid containing a perfluoroalkyl group in an amount of up to 0.5 wt % based on the total weight of the grease composition.

19. Grease composition according to one or more of the preceding claims, characterized in that The anion of the ionic liquid is bis(fluorosulfonyl)imide selected from the group consisting of: Trihexyl(tetradecyl)phosphoniumbis(fluorosulfonyl)imide Methyltrioctylammonium bis(fluorosulfonyl)imide Tributyltetradecylphosphoniumbis(fluorosulfonyl)imide Tetraoctylphosphonium bis(fluorosulfonyl)imide and mixtures thereof.

20. Grease composition according to one or more of the preceding claims, characterized in that Based on the total weight of the grease composition, the thickener accounts for 4wt% to 30wt%.

21. Grease composition according to one or more of the preceding claims, characterized in that The grease composition comprises 20 wt % to 92.5 wt % of a base oil based on the total weight of the grease composition and 4 wt % to 20 wt % of other thickeners based on the total weight of the grease composition, wherein the other thickeners are preferably selected from aluminum complex soaps, bentonites, sulfonates, silicates, polyimides and mixtures thereof.

22. Grease composition according to one or more of the preceding claims, characterized in that The urea is a urea which is a reaction product of a diisocyanate and an amine or diamine of the general formula (H2N)xR, wherein the diisocyanate is preferably 2,4-diisocyanate toluene, 2,6-diisocyanate toluene, 4,4'-diisocyanate diphenylmethane, 2,4'-diisocyanate diphenylmethane, 4,4'-diisocyanate diphenyl, 4,4'-diisocyanate-3,3'-dimethyldiphenyl, 4,4'-diisocyanate-3,3'-dimethylphenylmethane, which can be used alone or in combination, and the amine or diamine can exist alone or in combination, wherein x=1 or 2, and R is an aryl, alkyl, cycloalkyl or alkylene residue having 2 to 22 carbon atoms.

23. Grease composition according to one or more of the preceding claims, characterized in that The urea is a diurea comprising aliphatic, cycloaliphatic / aliphatic and / or cycloaliphatic urea, preferably a diurea expressed by formula A, wherein R2 is a divalent C6-15 aromatic hydrocarbon residue; R1 and R3 are independently a C6-20 cycloalkyl residue, in particular a cyclohexyl residue, or a straight-chain or branched C8-20 alkyl residue.

24. Grease composition according to one or more of the preceding claims, characterized in that The lithium complex soap is a lithium complex soap made from the following substances: C4-C36 dicarboxylic acids, preferably azelaic acid, sebacic acid, suberic acid, terephthalic acid, dodecanedioic acid, and / or high-functionality carboxylic acids having 3 or more, preferably 3 to 4 carboxylic acid groups, wherein the number of carbon groups can be 6 to 60, such as preferably citric acid and trimer acid, and / or ester compounds, especially methyl esters and / or triglycerides of one or more of the above acids, each in combination with one or more monocarboxylic acids, preferably in combination with one or more C4-C24 monocarboxylic acids, preferably stearic acid, hydroxystearic acid, especially 12-hydroxystearic acid, palmitic acid, oleic acid, salicylic acid, ester compounds, especially methyl esters and / or triglycerides of one or more of the above acids, and / or in combination with sebacic acid monostearate and / or terephthalic acid monostearate.

25. Grease composition according to one or more of the preceding claims, characterized in that Based on the total weight of the grease composition, the grease composition contains an aromatic amine as an additive in an amount of preferably 0.5wt% to 23wt%, more preferably 0.5wt% to 20wt%, and especially 0.5wt% to 10wt%. The aromatic amine is preferably selected from styrenated diphenylamine, phenyl-α-naphthylamine, phenyl-β-naphthylamine, octylated and / or butylated diphenylamine, especially p,p'-dioctyldiphenylamine and nonylated diphenylamine.

26. Grease composition according to one or more of the preceding claims, characterized in that According to IP 186 (2015 edition), the lower use temperature does not exceed -30°C, preferably does not exceed -40°C, and / or, according to DIN 51821 1+2 (2016, 7 edition), the upper use temperature is at least +160°C, preferably at least +180°C.

27. Use of a grease composition according to one or more of the preceding claims for lubricating drive elements, preferably for lubricating rolling bearings, gearboxes, plain bearings, actuators and / or chains, wherein preferably an electrical potential is present on the drive element.

28. The use according to claim 27, characterized in that The drive element is selected from pulley bearings, fan bearings, vacuum pump bearings, rolling bearings of electric motors (especially electric motors of hybrid vehicles and electric vehicles), generators (especially generators of electric vehicles and rail vehicles), wind power equipment, industrial motors, vehicle auxiliary devices and / or vehicle joints.

29. The use according to claim 27 or 28, characterized in that The grease composition is used for lubricating drive elements, preferably for lubricating rolling bearings, wherein according to IP 186 (2015 edition), the lower operating temperature of the grease composition is required to be no more than -30°C, preferably no more than -40°C, and / or, according to DIN 51821 1+2 (2016, 7 edition), the higher operating temperature is preferably required to be at least +160°C, preferably at least +180°C.

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