Lubricating grease

Abstract

The invention relates to a lubricating grease containing: a) 50 wt.% to 95.8 wt.%, based on the total weight of the lubricating grease, of at least one base oil; b) 4 wt.% to 20 wt.%, based on the total weight of the lubricating grease, of at least one thickener selected from urea thickeners, complex metallic soaps, in particular complex lithium soaps, complex aluminium soaps, complex calcium soaps, simple metal soaps of the elements of the first main group of the periodic table, in particular simple lithium soaps and mixtures thereof; c) 0.2 wt.% to 40 wt.%, based on the total weight of the lubricating grease, of at least one partially crystalline polyalphaolefin at least having a melting peak, measured according to DIN EN ISO 11357-3:2018, of above 10°C, and a degree of crystallinity of 15% to 45%, the degree of crystallinity of the partially crystalline polyalphaolefin being calculated by determining the melting enthalpy of the partially crystalline polyalphaolefin according to DIN EN ISO 11357-3:2018, and dividing it by 2.93 J / g.

Description

[0001] Grease

[0002] The invention relates to a lubricating grease with increased shear stability, as well as its use for lubricating the surfaces of sliding components. The invention further relates to a method for producing a tribological system using the lubricating grease, as well as to a tribological system containing the lubricating grease.

[0003] State of the art

[0004] Lubricants are essential components of many industrial processes involving two or more surfaces in close contact. The range of applications for lubricants is very broad and includes, among others, automotive lubricants, lubricants for two-stroke and four-stroke gasoline engines, lubricants for diesel engines, gas engine oils, gas turbine oils, automatic transmission fluids, gear oils, etc.

[0005] Lubricants can be in the form of lubricating oils or greases. Industrial lubricating oils include, among others, industrial gear oils, pneumatic tool lubricants, high-temperature oils, air and gas compressor oils for all types of compressors, machine tool oils, textile oils, steam turbine oils, hydraulic fluids, paper machine oils, food machine oils, steam cylinder oils, and metalworking fluids for metal cutting, metal rolling, metal drawing, metal forging, and metal stamping. Greases contain one or more thickeners in addition to the lubricating oil.

[0006] Lubricating greases usually contain a variety of substances (e.g. additives, thickeners, oils, auxiliaries, polymers) to regulate the lubricating grease properties and adapt the lubricating grease effect on the component.

[0007] Lubricating greases are often used to lubricate bearings.

[0008] Bearings are machine elements for guiding components that move relative to one another. Machine elements are components that fulfil the same or similar functions in different machines and devices and are therefore always present in the same or a similar form. Bearings can be differentiated according to the degree of freedom of possible movement, namely radial bearings, axial bearings, radial axis bearings and linear bearings. Bearings can also be differentiated according to their operating principle. In linear bearings, the components moving relative to one another are in direct contact, whereas in rolling bearings the moving components do not touch directly but are separated by rolling elements. Rolling bearings can be roller bearings or ball bearings. Roller bearings can be needle bearings, cylindrical roller bearings, tapered roller bearings and spherical roller bearings. Bearings are usually filled with lubricating grease during production, which is then sealed by suitable sealing elements in the bearing or housing.is kept in the lead.

[0009] A key criterion for lubricating greases is their shear stability. Shear stability is a mechanical parameter derived from structural stability. Shear stress leads to a mostly irreversible destruction or change of the grease. Shear stability indicates the resistance of the grease's consistency to shear stress. Low shear stability manifests itself in a significant or rapid decrease in the grease's consistency under shear stress.

[0010] The consequences of a reduction in consistency are negative effects on the lubricating film thickness, load-bearing capacity and an increase in wear on the component as well as a reduction in the service life of the lubricating grease and the lubricated components.

[0011] In order to increase shear stability, modified manufacturing processes or special shear-stable thickener concepts are currently used in practice, which lead to an increase in the base oil viscosity of greases.

[0012] For example, high-viscosity base oil components are used to achieve a high base oil viscosity in greases.

[0013] The use of specific additives to improve shear stability, however, is not common in practice. However, their existence would be desirable, as they would allow existing manufacturing processes and grease concepts to be retained and base oils with a low initial viscosity to be used.

[0014] It is well known that polymers are used in lubricating greases. These are generally used to improve viscosity / temperature behavior, increase viscosity and adhesion (tackifiers), or thicken the grease.

[0015] From DE 10 2017 222 515 A1 a grease composition is known which contains polyamide oligomers as thickeners.

[0016] EP 17050209 B1 and EP 1721959 A2 describe the use of microgels as carriers of additives, e.g. in lubricating greases and as rheology additives.

[0017] EP 1099717 A1 describes the use of star-shaped polymers to improve the viscosity index of lubricating greases.

[0018] WO 2012 / 055821 A1 describes the use of polymer fibers as thickeners for lubricating greases.

[0019] EP 079559701 A1 describes the combination of polymers with melting points >200 °C with co- and homopolymers of propylene as thickeners.

[0020] EP 1730256 B1 describes functionalized polymers as thickener components.

[0021] US 8975218 B2 describes the combination of two polymers (ethylene-propylene copolymer with styrene-isoprene copolymer) in a lithium soap grease to reduce oil separation at high temperatures.

[0022] EP 0942063 B1 describes the combination of a polyolefin component, such as polypropylene, with a rubber component as a thickener for lubricating greases.

[0023] None of the cited publications offers a concept for increasing the shear stability of lubricating greases through additives. The object of the invention is to provide a lubricating grease that exhibits high shear stability and whose production can be carried out using existing manufacturing processes and lubricating grease concepts.

[0024] This object is achieved by a lubricating grease containing a) 50 wt.% to 95.8 wt.%, based on the total weight of the lubricating grease, of at least one base oil, b) 4 wt.% to 20 wt.%, based on the total weight of the lubricating grease, of at least one thickener selected from urea thickeners, metal complex soaps, in particular lithium complex soaps, aluminum complex soaps, calcium complex soaps, metal simple soaps of the elements of the first main group of the periodic table, in particular lithium simple soaps and mixtures thereof, c) 0.2 wt.% to 40 wt.%, based on the total weight of the lubricating grease, at least one semi-crystalline polyalphaolefin with at least one melting peak, measured according to DIN EN ISO 11357-3:2018 above 10°C and a degree of crystallinity of 15% to 45%, wherein the degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin according to DIN EN ISO 11357-3:2018 and dividing it by 2.93 J / g.

[0025] In a preferred embodiment, the lubricating grease contains a) 50 wt.% to 92 wt.%, based on the total weight of the lubricating grease, of at least one base oil, b) 4 wt.% to 20 wt.%, based on the total weight of the lubricating grease, of at least one thickener selected from urea thickeners, metal complex soaps, in particular lithium complex soaps, aluminum complex soaps, calcium complex soaps, metal simple soaps of the elements of the first main group of the periodic table, in particular

[0026] Lithium simple soaps and mixtures thereof, c) 0.2 wt.% to 40 wt.%, based on the total weight of the lubricating grease, of at least one semi-crystalline polyalphaolefin with at least one melting peak, measured according to DIN EN ISO 11357-3:2018 above 10°C and a degree of crystallinity of 15% to 45%, wherein the degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin according to DIN EN ISO

[0027] 11357-3:2018 and divided by 2.93 J / g, d) 0.5 wt.% to 43 wt.% based on the total weight of the lubricating grease, at least one additive different from b) and c), in particular at least one solid lubricant (d1), at least one further thickener (d2) and / or at least one auxiliary substance (d3).

[0028] In a further preferred embodiment, the lubricating grease comprises a) 50 wt.% to 92 wt.%, based on the total weight of the lubricating grease, of at least one base oil, b) 4 wt.% to 20 wt.%, based on the total weight of the lubricating grease, of at least one thickener selected from urea thickeners, metal complex soaps, in particular lithium complex soaps, aluminum complex soaps, calcium complex soaps, metal simple soaps of the elements of the first main group of the periodic table, in particular lithium simple soaps and mixtures thereof, c) 0.2 wt.% to 40 wt.%, based on the total weight of the lubricating grease, at least one semi-crystalline polyalphaolefin with at least one melting peak, measured according to DIN EN ISO 11357-3:2018 above 10°C and a degree of crystallinity of 15% to 45%, wherein the degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin according to DIN EN ISO 11357-3:2018 and dividing it by 2.93 J / g, d) 0.5 to 43 wt.% based on the total weight of the lubricating grease, at least one further additive different from b) and c) comprising d1) 1 wt.% to 10 wt.%, based on the total weight of the.

[0029] lubricating grease, at least one solid lubricant, and / or d2) 1 wt.% to 10 wt.%, based on the total weight of the

[0030] Lubricating grease, at least one further thickener, preferably selected from aluminum simple soaps, calcium sulfonates, bentonites, amorphous silica, hydrophobized amorphous silica, silicates, polyimides and mixtures thereof, and / or d3) 0.5 wt.% to 23 wt.%, based on the total weight of the

[0031] Lubricating grease, at least one auxiliary substance, preferably selected from antioxidants, corrosion inhibitors, high-pressure additives, wear inhibitors, metal deactivators, in particular non-ferrous metal deactivators, for example chelating agents, pour point improvers, VI improvers, radical scavengers, UV stabilizers, reaction layer formers, adhesion improvers, electrical conductivity improvers, additives for reducing oil separation and mixtures thereof.

[0032] Partially crystalline polyalphaolefin c)

[0033] According to the invention, the lubricating grease comprises semi-crystalline polyalphaolefin with a degree of crystallinity of 15% to 45%. To determine the degree of crystallinity of the semi-crystalline polyalphaolefin, the enthalpy of fusion of the semi-crystalline polyalphaolefin is first determined according to DIN EN ISO 11357-3:2018 and the resulting enthalpy of fusion is divided by 2.93 J / g.

[0034] The value of 2.93 J / g results from the enthalpy of fusion of 100% crystalline polyethylene (UHMWPE). The crystallinity of the semi-crystalline polyalphaolefin is therefore based on 100% crystalline polyethylene. The enthalpy of fusion of 100% crystalline polyethylene can be determined using ASTM F 2625-10 (2016). This results in a enthalpy of fusion of 293 J / g. To relate the crystallinity of the semi-crystalline polyalphaolefin to 100% crystalline polyethylene (UHMWPE), the enthalpy of fusion of the polyalphaolefin determined according to DIN EN ISO 11357-3:2018 is divided by the enthalpy of fusion of 100% crystalline polyethylene, i.e., by 293 J / g, and multiplied by 100. This corresponds to a division by 2.93 J / g.

[0035] The semi-crystalline polyalphaolefin according to the invention has at least one melting peak, measured according to DIN EN ISO 11357-3:2018, above 10°C. This distinguishes it from the polyalphaolefins conventionally used as base oils.

[0036] According to the invention, it was surprisingly found that the use of a semi-crystalline polyalphaolefin with a crystallinity of 15% to 45% in combination with a thickener selected from urea thickeners, metal complex soaps, in particular lithium complex soaps, aluminum complex soaps, calcium complex soaps, metal simple soaps of the elements of the first main group of the periodic table, in particular lithium simple soaps, and mixtures, makes it possible to improve the shear stability of lubricating greases. Thus, in practical tests, it was surprisingly found that the thickeners used according to the invention, in combination with the semi-crystalline polyalphaolefin, lead to significantly increased shear stability, whereas the combination of a calcium soap as a thickener with semi-crystalline polyalphaolefin leads to no improvement but, on the contrary, to a deterioration in shear stability.

[0037] Without committing to a specific mechanism, it is assumed that the observed shear stability-enhancing effect is due to the fact that semi-crystalline polyalpaolefins with a degree of crystallization of 15% to 45%, in combination with the selected thickeners, can create structuring properties or improve structuring properties already present in the lubricating grease. It is further suspected that polyalpaolefins with a degree of crystallization outside the claimed range do not have a shear stability-enhancing effect because they do not interact with the thickeners. Thus, polyalpaolefins with a degree of crystallization below 15% appear to interact primarily with the base oil but not with the thickeners, while polyalpaolefins with a degree of crystallization above 45% appear to interact significantly neither with the base oil nor with the thickener.

[0038] Preferred semi-crystalline polyalpaolefins have a degree of crystallization of 20% to 35%, determined by measuring the enthalpy of fusion of the semi-crystalline

[0039] Polyalphaolefins, based on DIN EN ISO 11357-3:2018, and divided by 2.93 J / g.

[0040] Suitable semi-crystalline polyalphaolefins include oligomers and / or polymers of α-olefin. Semi-crystalline polyalphaolefins with a crystallinity of 15% to 45% can be prepared, for example, by oligomerization or polymerization of a starting material comprising α-olefin and internal olefin.

[0041] As is known to the person skilled in the art, the degree of crystallinity can be adjusted, for example, by suitable selection of the starting materials, in particular the chain length of the alpha olefins used, their proportions, the catalysts and / or the reaction conditions.

[0042] Semi-crystalline polyalphaolefins suitable for use in accordance with the invention are also commercially available, for example, under the brand names Vybar® 260 or Vybar® C-6112. Semi-crystalline polyalphaolefins such as Vybar® 260 are also described in US 2004 / 0040200 A1 and US Pat. No. 4,224,204 A. The semi-crystalline polyalphaolefin used in accordance with the invention, with a crystallinity of 15% to 45%, can contain only a single type of semi-crystalline polyalphaolefin or various types of semi-crystalline polyalphaolefins. The different types of semi-crystalline polyalphaolefins can differ in their crystallinity, provided that this is 15% to 45% for each type (determined by determining the enthalpy of fusion of the polyalphaolefin according to DIN EN ISO 11357-3:2018 (April 2019) and dividing it by 2.93 J / g).The various semi-crystalline polyalphaolefins can also differ in other parameters, such as molecular weight, chain length and / or degree of branching.

[0043] As stated above, the semi-crystalline polyalphaolefin can be prepared by polymerization or oligomerization of an olefin-containing starting material comprising α-olefin and / or internal olefin.

[0044] The olefin (α-olefin and / or internal olefin) used to produce the semi-crystalline polyalphaolefin preferably has at least 14 carbon atoms. The olefin preferably has 14 to 50 carbon atoms, preferably 14 to 44, more preferably 14 to 30, more preferably 16 to 50 carbon atoms, more preferably 16 to 44, even more preferably 16 to 30, and especially 20 to 24 carbon atoms.

[0045] The α-olefin can have the structure RCH=CH2 or R2C=CH2. The R radicals, independently of one another, are preferably alkyl with 14 to 50 carbon atoms.

[0046] The starting material preferably contains an α-olefin of the structure RCH=CH2. Suitable α-olefins include, for example, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 1-docosene, and 1-tetradocosene. Mixtures of these substances are typically used. The α-olefin can be linear or branched.

[0047] The olefin can be produced by a variety of processes, for example by polymerizing olefins such as ethylene in the presence of Ziegler-type catalysts.

[0048] An internal olefin has at least one double bond within the molecule. Examples are ß-olefins and γ-olefins.

[0049] The starting material may also comprise other conventional components for polymerizable compositions, for example polymerization catalysts.

[0050] The polymerization of the olefin-containing starting material can be carried out using a conventional process, provided that a semi-crystalline polyalphaolefin with a crystallinity of 15% to 45% is obtained. Suitable processes include radical polymerization (using conventional radical methods such as thermal decomposition, photoinitiation, electrochemical initiation, etc., and using chemical radical initiators such as azo or diazo compounds, peroxides or hydroperoxides, etc.), coordination polymerization, etc.

[0051] A particularly preferred semi-crystalline polyalphaolefin has an acid number according to ASTM D664-18e1 of 10 mg KOH / g to 120 mg KOH / g, preferably 40 mg KOH / g to 100 mg KOH / g. The acid number is due to acid groups contained in the polyalphaolefin. In practical tests, such semi-crystalline polyalphaolefins have proven particularly effective.

[0052] A particularly preferred semi-crystalline polyalphaolefin is a mixture of at least two different semi-crystalline polyalphaolefins, wherein at least one semi-crystalline polyalphaolefin has an acid number according to ASTM D664-18e1 of 10 mg KOH / g to 120 mg KOH / g, preferably of 40 mg KOH / g to 100 mg KOH / g, and at least one other semi-crystalline polyalphaolefin has an acid number according to ASTM D664-18e1 of less than 10 mg KOH / g.

[0053] A particularly preferred semi-crystalline polyalphaolefin is Vybar® C-6112®, available from Baker Hughes Incorporated (Baker Petrolite Polymers Division).

[0054] A partially crystalline polyalphaolefin preferred according to the invention has a molecular weight Mn, measured according to DIN 55672-1:2016-03 of more than 2500 g / mol, for example from 2500 g / mol to 37000 g / mol, more preferably from 2500 g / mol to 5600 g / mol, in particular from Mn 3000 g / mol to Mn 5600 g / mol.

[0055] The semi-crystalline polyalphaolefin is preferably waxy at room temperature (20°C). In a preferred embodiment of the invention, the semi-crystalline polyalphaolefin has a solidification point according to DIN ISO 2207:1983-12 between 60°C and about 90°C. Furthermore, the viscosity of the semi-crystalline polyalphaolefin at 100°C can be between 30 cPs and 1800 cPs, preferably at 100°C between about 80 and 220 cPs, measured according to ASTM D3236-15(2021). The amount of semi-crystalline polyalphaolefin is preferably in the range of 1 wt.% to 25 wt.%, more preferably in the range of 3 wt.% to 20 wt.%, in particular in the range of 3 wt.% to 10 wt.%, in each case based on the total weight of the lubricating grease.

[0056] Thickener b)

[0057] According to the invention, the lubricating grease comprises at least one thickener b) selected from urea thickeners, metal complex soaps, in particular lithium complex soaps, aluminum complex soaps, calcium complex soaps, metal simple soaps of the elements of the first main group of the periodic table, in particular lithium simple soaps, and mixtures thereof.

[0058] Preferred thickeners b) are selected from urea thickeners, lithium complex soaps, lithium simple soaps and mixtures thereof.

[0059] Thickeners are solid substances (insoluble solids) that are almost or completely insoluble in the base oils and have a thickening effect. By adding thickeners, lubricating oils can be converted into lubricating greases. Lubricating greases are compounds that contain a liquid phase (at room temperature 20°C) and solids. The consistency of lubricating greases can be measured using a standardized measurement method in the form of the so-called

[0060] Determine worked penetration according to DIN ISO 2137 (2020). The worked penetration is measured after working the lubricating grease in a grease kneader or lubricating grease walker using a penetrometer as the penetration depth of a standard cone under defined conditions. The assignment of the measured cone penetration to a defined NLGI class (NLGI = National Lubricating Grease Institute) is then carried out according to DIN 51818 (1.12 1981). Lubricating greases according to the invention preferably have a worked penetration of 85 to 475, more preferably 220 to 400 cone penetration in 0.1 mm when measured according to DIN ISO 2137 (2020). The proportion of the thickener b), based on the

[0061] Total weight of the grease from 6 wt.% to 18 wt.%, more preferably from

[0062] 8 wt% to 15 wt%.

[0063] Urea thickener

[0064] In a preferred embodiment, the lubricating grease contains a urea thickener. The advantage of urea thickeners is that they can be used even at high application temperatures. The urea thickener is preferably a reaction product of organic mono-, di-, tri-, and / or higher-functional isocyanates with aliphatic and / or aromatic mono-, di-, tri-, and / or higher-functional organic amines and / or mixtures thereof.

[0065] In a preferred embodiment, the urea thickener is an alkylated and / or arylated (oligo)urea. Preferred urea thickeners are the reaction products of at least one diisocyanate with at least one amine selected from monoamines, polyamines, and mixtures thereof. The diisocyanate is preferably selected from 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanatodiphenylmethane, 2,4'-diisocyanatophenylmethane, 4,4'-

[0066] Diisocyanatodiphenyl, 4,4'-diisocyanato-3,3'-dimethylphenyl, 4,4'-diisocyanato-3,3'-dimethylphenylmethane and mixtures thereof.

[0067] Preferably, the amine is selected from monoamines of the formula R a 2N-R b , diamines of the formula R a 2N-R c -NR a 2 and mixtures thereof, where

[0068] R a is independently selected from hydrogen, linear or branched C1-C22 alkyl and Cs-Cu aryl,

[0069] R b is independently selected from linear or branched Ci-C22 alkyl and Cs-Ci4 aryl radicals,

[0070] R c is a divalent bridging group preferably selected from C1-C22 alkylene and Cs-Cu arylene.

[0071] A preferred urea thickener is a reaction product of at least one diisocyanate, preferably 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 individually or in combination, with an amine or diamine of the general formula (H2N) x R d , where x = 1 or 2, and R d a Cs-Cu aryl, Cs-C22 alkyl, Cs-C22 cycloalkyl or Cs-C22 alkylene radical, which may be used individually or in combination.

[0072] In a particularly preferred embodiment, the urea thickener is a reaction product of a diisocyanate, preferably 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanatodiphenylmethane 2,4'-

[0073] Diisocyanatodiphenylmethane, 4,4'-diisocyanatodiphenyl, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 4,4'-diisocyanato-3,3'-dimethylphenylmethane, which can be used individually or in combination with an amine of the general formula (H2N)i R e , where R e a Cs-Cu aryl, Cs-C22 alkyl, Cs-C22 cycloalkyl or Cs-C22 alkylene radical, which may be used individually or in combination.

[0074] In a particularly preferred embodiment, the urea thickener is a reaction product of 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene and / or 4,4'-diisocyanatodiphenylmethane, preferably a mixture of 2,4-diisocyanatotoluene and 2,6-diisocyanatotoluene or preferably a mixture of 2,4-

[0075] Diisocyanatotoluene, 2,6-diisocyanatotoluene and 4,4'-diisocyanatodiphenylmethane or preferably 4,4'-diisocyanatodiphenylmethane with an amine of the general formula (H2N)i R e , where R ea Cs-Cu aryl, Cs-C22 alkyl, Cs-C22 cycloalkyl or Cs-C22 alkylene radical, which may be used individually or in combination.

[0076] Metal complex soaps and metal simple soaps of the elements of the first main group of the periodic table

[0077] In a further preferred embodiment, the lubricating grease contains as thickener b) metal complex soaps and / or metal simple soaps, wherein the metal simple soaps are metal simple soaps of the elements of the first main group of the periodic table. According to the invention, preference is given to

[0078] Calcium complex soaps, aluminum complex soaps, lithium complex soaps, lithium simple soaps, and / or mixtures thereof. Suitable metal complex soaps can be obtained by reacting a metal base (such as a hydroxide, alcoholate, oxide, or carbonate) with e) at least one aliphatic monocarboxylic acid component selected from unsaturated or saturated C10-C32 monocarboxylic acids or unsaturated or saturated C10-C32 hydroxy monocarboxylic acids and derivatives of said C10-C32 monocarboxylic acids and C10-C32 hydroxy monocarboxylic acids, preferably their esters and mixtures, and f) at least one complexing agent.

[0079] Preferred esters for components e) and f) are, independently of one another, methyl esters and / or triglycerides. Preferred metal bases are metal hydroxides, preferably lithium hydroxide, calcium hydroxide, and / or metal alkoxides, preferably aluminum alkoxides.

[0080] The aliphatic monocarboxylic acid component e) is preferably selected from saturated or unsaturated Ci2-C22 monocarboxylic acids, saturated or unsaturated Ci2-C22 hydroxymonocarboxylic acids and their esters and mixtures. In particular, the monocarboxylic acids and hydroxymonocarboxylic acids e) are selected from lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, myristoleic acid, palmitoleic acid, oleic acid, linoleic acid, arachidonic acid, behenic acid, stearic acid, hydroxystearic acid, preferably 12-hydroxystearic acid, 17-hydroxystearic acid, 2-hydroxytetradecanoic acid, 3-hydroxytetradecanoic acid, 2-hydroxyhexadecanoic acid, 3-hydroxyhexadecanoic acid, sebacic acid monostearylamide, terephthalic acid monostearylamide, their esters, in particular methyl esters and / or triglycerides and mixtures thereof.

[0081] More particularly preferably, the carboxylic acid component e) contains a mixture of different carboxylic acids and / or their esters.

[0082] The complexing agent f) is preferably selected from saturated or unsaturated C1-C6 monocarboxylic acids, saturated or unsaturated C2-C36 dicarboxylic acids, preferably C4-C36 dicarboxylic acids, in particular C2-C16 dicarboxylic acids, saturated or unsaturated C4-C10 tricarboxylic acids, preferably C4-C36 tricarboxylic acids, saturated or unsaturated C8-C10 carboxylic acids with 4 or more carboxylic acid groups, preferably with 4 carboxylic acid groups, saturated or unsaturated C2-C8 hydroxy monocarboxylic acids, C4-C36 arylcarboxylic acids, their esters, in particular their methyl esters and / or triglycerides, inorganic acids, in particular boric acid, phosphoric acid and organophosphoric acids and mixtures thereof.

[0083] More preferably, the complexing agent f) is selected from saturated or unsaturated C1-C6 monocarboxylic acids, saturated or unsaturated C2-C36 dicarboxylic acids, preferably C4-C36 dicarboxylic acids, in particular C2-C16 dicarboxylic acids, saturated or unsaturated C4-C60 tricarboxylic acids, preferably C4-C36 tricarboxylic acids, saturated or unsaturated C8-C9 carboxylic acids having 4 or more carboxylic acid groups, preferably having 4 carboxylic acid groups, saturated or unsaturated C2-C8 hydroxy monocarboxylic acids, C4-C36 arylcarboxylic acids, their esters, in particular their methyl esters and / or triglycerides, and mixtures thereof.

[0084] Particularly suitable dicarboxylic acids f) are adipic acid, sebacic acid, azelaic acid, 3-tert-butyladipic acid, and their esters and mixtures. Hydroxybenzoic acids, e.g., salicylic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2-hydroxy-4-hexylbenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, and 4-hydroxy-4-methoxybenzoic acid, are also particularly suitable as component f). Lactic acid, acetic acid, and / or propionic acid are particularly suitable as C1-C5 monocarboxylic acids.

[0085] In a particularly preferred embodiment, the complexing agent f) is selected from aliphatic C1-C5 monocarboxylic acids, aliphatic C4-C36 dicarboxylic acids, aliphatic C4-C36 tricarboxylic acids, C4-C36 arylcarboxylic acids, their esters, in particular their methyl esters and / or triglycerides, and mixtures thereof.

[0086] In a further particularly preferred embodiment, the complexing agent f) is selected from acetic acid, propionic acid, lactic acid, salicylic acid, benzoic acid; azelaic acid, sebacic acid, suberic acid, terephthalic acid, dodecanedioic acid, higher-functional carboxylic acids having 3 or more, preferably 3 to 4 carboxylic acid groups, where the number of carbon groups can be 6 to 60, preferably citric acid and trimer acids, their esters, in particular their methyl esters and / or triglycerides, and mixtures thereof.

[0087] In a further particularly preferred embodiment, the complexing agent f) is selected from acetic acid, propionic acid, lactic acid, salicylic acid, benzoic acid, azelaic acid, sebacic acid, dodecanedioic acid, their esters, in particular their methyl esters and / or triglycerides, and mixtures thereof.

[0088] In a further particularly preferred embodiment, the complexing agent f) is selected from azelaic acid, sebacic acid, their esters, in particular their methyl esters and / or triglycerides, and mixtures thereof.

[0089] Preferred inorganic acids f) are boric acid, phosphoric acid and organophosphoric acid.

[0090] The aliphatic monocarboxylic acid component e) and the complexing agent f) can independently of one another have further functionalities, preferably alcoholic hydroxide groups and / or acid amide groups, with the proviso that the monocarboxylic acid component e) has at most one acid group or ester group.

[0091] Particularly preferred metal complex soaps can be obtained by reaction of a metal base selected from lithium hydroxide, calcium hydroxide and / or

[0092] Metal alcoholates, preferably aluminum alcoholates, with e) at least one aliphatic monocarboxylic acid component selected from unsaturated or saturated C10-C23 monocarboxylic acids, preferably stearic acid, hydroxystearic acid, in particular 12-hydroxystearic acid, palmitic acid, oleic acid, sebacic acid monostearylamide, terephthalic acid monostearylamide, their esters, in particular their methyl esters and / or triglycerides, and mixtures thereof, and f) at least one complexing agent selected from acetic acid, propionic acid, lactic acid, salicylic acid, benzoic acid, azelaic acid, sebacic acid, dodecanedioic acid, their esters, in particular their methyl esters and / or triglycerides, and mixtures thereof.

[0093] Metal complex soaps are preferably produced from mixtures of different acids and / or their esters, since the technically available products usually contain such mixtures.

[0094] In a further preferred embodiment, the metal complex soap is prepared by reacting a metal base with e1) at least one aliphatic monocarboxylic acid component selected from unsaturated or saturated C10-C32 monocarboxylic acids, their esters, in particular methyl esters and / or triglycerides and / or mixtures, and e2) at least one aliphatic unsaturated or saturated C10-C32 monocarboxylic acid different from e1), preferably stearic acid, hydroxystearic acid, in particular 12-hydroxystearic acid, palmitic acid, oleic acid, sebacic acid monostearylamide and / or terephthalic acid monostearylamide, their esters, in particular methyl esters and / or triglycerides and mixtures, and f) at least one complexing agent selected from unsaturated or saturated C4-C36 dicarboxylic acids, preferably azelaic acid, sebacic acid, suberic acid, terephthalic acid, dodecanedioic acid,At least one unsaturated or saturated higher-functionality carboxylic acid with 3 or more, preferably 3 to 4 carboxylic acid groups, where the number of carbon groups can be from 6 to 60, such as preferably citric acid and trimer acid, their esters, especially methyl esters and / or triglycerides, and mixtures. The advantage of using lithium complex soaps is that they can impart high dropping points, good water resistance, and wide operating temperature ranges to the lubricating grease. Therefore, in a preferred embodiment, the lubricating grease contains lithium complex soaps.

[0095] Preferred lithium complex soaps contain lithium 12-hydroxystearate in combination with dilithium azelate and / or in combination with dilithium sebacate. Most preferably, the metal complex soap is a lithium complex soap containing lithium salts of 12-hydroxystearic acid combined with azelaic acid or sebacic acid, especially 12-hydroxystearic acid combined with azelaic acid.

[0096] In a likewise preferred embodiment, the lubricating grease contains aluminum complex soaps and / or calcium complex soaps. Preferred aluminum complex soaps contain aluminum stearate and aluminum benzoate. Preferred calcium complex soaps contain calcium monostearyl sebacate in combination with calcium sebacate.

[0097] Metal simple soaps of the elements of the first main group of the periodic table

[0098] In a likewise preferred embodiment, the lubricating grease contains metal simple soaps of the elements of the first main group of the periodic table, in particular lithium simple soaps.

[0099] Metal simple soaps can be produced from fatty acids and / or fatty acid esters by reacting them with metal bases. In contrast to metal complex soaps, no complexing agents, in particular no complexing agents selected from saturated or unsaturated C1-C3 monocarboxylic acids, saturated or unsaturated C2-C36 dicarboxylic acids, preferably C4-C36 dicarboxylic acids, in particular C2-C16 dicarboxylic acids, saturated or unsaturated C4-C60 tricarboxylic acids, preferably C4-C36 tricarboxylic acids, saturated or unsaturated C6-C60 carboxylic acids with 4 or more carboxylic acid groups, preferably with 4 carboxylic acid groups, saturated or unsaturated C2-C8 hydroxy monocarboxylic acids, C4-C36 arylcarboxylic acids, their esters, in particular their methyl esters and / or triglycerides, inorganic acids, in particular boric acid, phosphoric acid and organophosphoric acids, and mixtures thereof, are used to produce metal simple soaps.

[0100] Preferably, metal simple soaps contain carboxylate only in the form of monofunctional carboxylate.

[0101] Metal simple soaps are preferably produced from mixtures of different carboxylic acids and / or their esters, since the technically available products usually contain such mixtures.

[0102] Suitable metal simple soaps are prepared by reacting a metal base (such as a hydroxide, alcoholate, oxide or carbonate) with at least one aliphatic monocarboxylic acid component having 4 to 36 carbon atoms, preferably 4 to 24 carbon atoms, in particular 10 to 32 carbon atoms, preferably selected from unsaturated or saturated C4-C24 monocarboxylic acids, preferably stearic acid, hydroxystearic acid, in particular 12-

[0103] Hydroxystearic acid, palmitic acid, oleic acid, sebacic acid monostearylamide, terephthalic acid monostearylamide, their esters, in particular methyl esters and / or triglycerides and mixtures.

[0104] Particularly preferred lithium simple soaps are lithium salts of stearic acid, in particular lithium 12-hydroxystearate.

[0105] Base oil a)

[0106] According to the invention, the lubricating grease comprises 50 wt.% to 95.8 wt.%, preferably 50 wt.% to 92 wt.%, more preferably from 60 wt.% to 92 wt.%, even more preferably from 70 wt.% to 90 wt.%, based on the total weight of the lubricating grease, base oil.

[0107] A base oil is understood to mean the base fluids customarily used for the production of lubricating greases, in particular oils that can be assigned to groups I, ii, II+, iii, IV or V according to the classification of the American Petroleum Institute (API) [NLGI Spokesman, N. Samman, Volume 70, Number U, p. 14ff]. Particularly preferred base oils are selected from the group consisting of esters, ethers, mineral oils, synthetic hydrocarbons, in particular polyalphaolefin and / or polyisobutylenes, natural hydrocarbons, native oils and derivatives of native oils, silicone oils, and / or mixtures thereof. The base oil is different from the semi-crystalline polyalphaolefin.Preferably, the base oil is not a polyalphaolefin with at least one melting peak, measured according to DIN EN ISO 11357-3:2018, above 10°C and / or not a polyalphaolefin with a degree of crystallinity of 15% to 45%, wherein the degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin, according to DIN EN ISO 11357-3:2018, and dividing it by 2.93 J / g.

[0108] According to the invention, the semi-crystalline polyalphaolefin is not considered a base oil. However, the base oil can be polyalphaolefin or contain polyalphaolefin (polyalphaolefin base oil), provided the polyalphaolefin is different from the semi-crystalline polyalphaolefin. Polyalphaolefin base oil preferably has no melting peak, measured according to DIN EN ISO 11357-3:2018, above 10°C and / or no degree of crystallinity of 15% to 45%. The degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin according to DIN EN ISO 11357-3:2018 and dividing it by 2.93 J / g. Polyalphaolefin base oil can be distinguished from semi-crystalline polyalphaolefin based on its melting behavior.

[0109] Particularly preferred base oils according to the invention are esters, ethers, mineral oils, synthetic hydrocarbons, preferably polyalphaolefin base oil, in particular metallocene-catalyzed polyalphaolefin base oils (mPAO base oils), and / or mixtures thereof.

[0110] Particularly preferred base oils according to the invention are esters, ethers, synthetic hydrocarbons, preferably polyalphaolefin base oil, in particular metallocene-catalyzed polyalphaolefin base oils (mPAO base oils), and / or mixtures thereof. In a specific embodiment, the lubricating grease contains, as base oil, at least one ester selected from pentaerythritol esters, dipentaerythritol esters, trimellitic acid esters, hemimellitic acid esters, pyromellitic acid esters, estolides, dimer acid esters, trimer acid esters, trimethylolpropane esters (TMP esters), neopentyl glycol esters, dicarboxylic acid esters, and mixtures thereof.

[0111] Preferred esters are carboxylic acid esters, especially monoesters, diesters, triesters, tetraesters, pentaesters, polyesters, aromatic esters, and mixtures thereof. The carboxylic acid esters preferably have a chain length of C4 to C22.

[0112] Particularly preferred esters are selected from the group consisting of an ester of an aromatic and / or aliphatic di-, tri- or tetracarboxylic acid with one or a mixture of C7-C22 alcohols, an ester of trimethylolpropane, pentaerythritol or dipentaerythritol with aliphatic C?- to C22 carboxylic acids, C -dimer acid esters with C7- to C22 alcohols, as well as complex esters and estolides.

[0113] The base oil is more preferably selected from ethers, preferably polyphenyl ethers, diaryl ethers, triaryl ethers, polytetrahydrofuran (poly-THF) and / or polyglycols, preferably homo- and / or copolymers of ethylene oxide, propylene oxide, 1,2-butylene oxide, preferably initiated with monoalcohols, dialcohols, trialcohols, water and / or higher-hydric alcohols having 4, 5 or more alcoholic OH groups. Suitable higher-hydric alcohols include, for example, pentaerythritol and dipentaerythritol.

[0114] In a specific embodiment, the lubricating grease according to the invention contains at least one ether selected from polyalkylene glycols (PAGs) as the base oil. Suitable poly(alkylene) glycols (PAGs) are homopolymers, copolymers, and blends thereof. For the purposes of the invention, the term copolymer also refers to polymers composed of three, four, or more different monomers (terpolymers, quaterpolymers, etc.). Suitable poly(alkylene) glycols are polyethylene glycols, polypropylene glycols, polybutylene glycols, and copolymers of two or more different alkylene oxide copolymers. Suitable alkylene oxides for the production of poly(alkylene) glycols include, for example, ethylene oxide, propylene oxide, epichlorohydrin, 1,2-, and 2,3-butylene oxide. Suitable examples of copolymers are copolymers of ethylene oxide and propylene oxide, copolymers of ethylene oxide and butylene oxide and copolymers of ethylene oxide, propylene oxide and at least one butylene oxide.The alkylene oxide copolymers may contain the copolymerized alkylene oxide units in randomly distributed form or in the form of blocks.

[0115] Particularly preferred polyalkylene glycols are polypropylene oxide and / or copolymers of ethylene oxide and propylene oxide.

[0116] Linear or branched perfluoropolyether oils (PFPE oils) are also suitable as base oils. Suitable examples include perfluoropolyethers (PFPE) with the formula:

[0117] RA-(O-CF2)v-(O-C2F4)w-(O-C3F6)x-(O-CFCF3) y -(O-CF2CF(CF3))zO-RB where RA and RB are identical or different and are selected from -CF3, -C2F5 and -C3F7, and v, w, x, y, z are integers from > 0 to 500. PFPE oils are marketed, for example, under the brand names Aflunox®, Krytox®, Fomblin® and Demnum®.

[0118] Synthetic hydrocarbons, mineral oils, and mixtures thereof are also advantageously suitable as base oils. The synthetic hydrocarbons are different from the semi-crystalline polyalphaolefin used according to the invention. Preferably, the synthetic hydrocarbons do not have a melting peak, measured according to DIN EN ISO 11357-3:2018, above 10°C and / or do not have a degree of crystallinity of 15% to 45%, whereby the degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin according to DIN EN ISO 11357-3:2018 and dividing it by 2.93 J / g. Polyalphaolefin base oil can be distinguished from semi-crystalline polyalphaolefin based on its melting behavior. Group III oils are also advantageously suitable as base oils.Group III oils (hydrocracked synthetic oils) are synthetic hydrocarbons derived from petroleum base oils, produced entirely by hydrocracking, hydroisomerization, and hydrodesulfurization. They have a minimum of 90 percent saturates and a maximum of 0.03 percent sulfur, as well as a viscosity index of at least 120.

[0119] GTL oils (gas-to-liquids oils) are also suitable as base oils. GTL oils are based on synthesis gas consisting of hydrogen and carbon monoxide, from which longer-chain hydrocarbons are produced using Fischer-Tropsch synthesis.

[0120] Preferred synthetic hydrocarbons are polyalphaolefin base oils. As explained above, polyalphaolefin base oils are different from the semi-crystalline polyalphaolefin used in the invention. Polyalphaolefin base oils are also referred to as Group IV oils and generally have a viscosity index in the range of 125 to 200. Polyalphaolefin base oils can be produced catalytically from ethylene using known processes, initially yielding alphaolefins with longer chain lengths as intermediates. From these, the polyalphaolefin base oils are synthesized essentially by oligomerization, usually producing isoparaffins with a varying number of equally long side chains. The synthesis can be carried out by acid-catalyzed (conventional) or metallocene-catalyzed olefin polymerization (mPAO).Conventional polyalphaolefin base oils exhibit a high degree of isomerization, whereas metallocene oligomerization results in products that are essentially free of isomerization. Suitable polyalphaolefin base oils include oligomers, preferably dimers, trimers, tetramers, pentamers, and higher oligomers with more than 5 repeating units of alphaolefins, and mixtures of these oligomers. The alphaolefins used to produce the polyalphaolefin base oils are preferably selected from Cs-Cu alphaolefins, in particular 1-octene, 1-decene, 1-dodecene, and mixtures thereof.

[0121] Polyalphaolefin base oils are generally mixtures of oligomers or polymers derived from an α-olefin or isomerized α-olefin. Silicone oils are also advantageous as base oils. Dimethyl silicone oils and / or phenylmethyl silicone oils are preferred.

[0122] In a specific embodiment of the invention, the base oil is a fluorine-free base oil, preferably selected from pentaerythritol esters, dipentaerythritol esters, trimellitic acid esters, hemimellitic acid esters, pyromellitic acid esters, estolides, dimer acid esters, trimer acid esters, dicarboxylic acid esters, diaryl ethers, polyglycols, synthetic hydrocarbons, conventional polyalphaolefin base oils (PAO base oils), metallocene-catalyzed polyalphaolefin base oils (mPAO base oils); mineral oils, untreated and chemically modified vegetable oils, Group III oils, dimethylsilicone oils, and mixtures. Preferred ethers are homo- and / or copolymers of ethylene oxide, propylene oxide, 1,2-butylene oxide, and / or tetrahydrofuran (THF), preferably initiated with monoalcohols, dialcohols, and trialcohols. Preferred synthetic hydrocarbons are alkylated naphthalenes and polyalphaolefin base oils.

[0123] Preferably, the base oil has a kinematic viscosity, determined according to ASTM-D-7042, September 2014 edition, at 40°C of less than 20000 mm 2 / s, preferably 10 mm 2 / s up to 2000 mm 2 / s and especially 15 mm 2 / s up to 1000 mm 2 / s and / or a kinematic viscosity, determined according to ASTM-D-7042, September 2014 edition, at 100°C of 1 mm 2 / s up to 2000 mm 2 / s on.

[0124] Preferred polyalphaolefin base oil has a kinematic viscosity, determined according to ASTM-D-7042, September 2014 edition, at 40°C of 10 mm 2 / s up to 15000 mm 2 / s, preferably 15 mm 2 / s up to 10000 mm 2 / s, especially 15 mm 2 / s up to 1300 mm 2 / s. Also preferred is polyisobutylene base oil, which has a kinematic viscosity, determined according to ASTM-D-7042, September 2014 edition, at 100°C of 25 mm 2 / s up to 15000 mm 2 / s, preferably from 100mm 2 / s up to 2000 mm 2 / s , especially 200 mm 2 / s up to 1000 mm 2 / s on.

[0125] In a further preferred embodiment of the invention, the base oil is selected from the group consisting of esters, preferably dipentaerythritol esters, trimellitic acid esters, hemimellitic acid esters, pyromellitic acid esters, estolides, pentaerythritol esters, dimer acid esters, trimer acid esters, TMP esters, dicarboxylic acid esters, each with a kinematic viscosity at 40°C determined according to ASTM-D-7042, September 2014 edition of 100 mm 2 / s up to 1200 mm 2 / s; ethers, preferably polytetrahydrofuran (poly-THF), polyphenyl ethers, diaryl ethers, triaryl ethers, linear or branched perfluoropolyether oils, each with a kinematic viscosity at 40°C determined according to ASTM-D-7042, September 2014 edition, of 20 mm 2 / s up to 1200 mm 2 / s; polyglycols, preferably homo- and / or copolymers of ethylene oxide, propylene oxide, 1,2-butylene oxide, preferably initiated with water, monoalcohols, dialcohols and / or trialcohols, each with a kinematic viscosity at 40°C determined according to ASTM-D-7042, September 2014 edition, of 20 mm 2 / s up to 46000 mm 2 / s; synthetic hydrocarbons, preferably alkylated naphthalenes, polyalphaolefin base oils (PAO base oils), metallocene polyalphaolefin base oils (mPAO base oils), each with a kinematic viscosity at 40°C determined according to ASTM-D-7042, September 2014 edition, of 10 mm 2 / s up to 20000 mm 2 / s; Group III oils with a kinematic viscosity at 40°C determined according to ASTM-D-7042, September 2014 edition, of 10 mm 2 / s up to 100 mm 2 / s, dimethyl silicone oils, arylated silicone oils, preferably alkylaryl silicone oils, in particular methyl / aryl silicone oils and fully arylated silicone oils, each with a kinematic viscosity at 40°C determined according to ASTM-D-7042 edition September 2014 of 10 mm 2 / s up to 1200 mm 2 / s and / or each with a kinematic viscosity at 25°C determined according to DIN 53019, edition 2008.09 of 20 to 2000000 mm 2 / s, which can be used individually or in combination.

[0126] Other additives

[0127] The lubricating grease may comprise the thickener b) and the semi-crystalline polyalphaolefin c) as well as various other additives d).

[0128] If a component used as a further additive in the lubricating grease according to the invention has multiple effects, e.g. as a thickener and friction coefficient modifier, and is accordingly also referred to in this application as an additive for multiple purposes, its quantity is fully attributed to each of these additive components. In a preferred embodiment, the lubricating grease contains 0.5 to 43 wt.%, preferably 1 wt.% to 30 wt.%, more preferably 3 wt.% to 25 wt.%, based on the total weight of the lubricating grease, of at least one additive d) different from the thickener b) and the semi-crystalline polyalphaolefin c), in particular at least one solid lubricant (d1), at least one further thickener (d2) different from the thickener b), and / or at least one auxiliary substance (d3).

[0129] Particularly preferably, the lubricating grease contains 0.5 wt.% to 43 wt.%, based on the total weight of the lubricating grease, of at least one further additive d) different from b) and c), comprising d1) 1 wt.% to 10 wt.%, based on the total weight of the

[0130] lubricating grease, at least one solid lubricant, and / or d2) 1 wt.% to 10 wt.% based on the total weight of the

[0131] Lubricating grease, at least one further thickener different from b), preferably selected from aluminum simple soaps, calcium sulfonates, bentonites, amorphous silica, hydrophobized amorphous silica, silicates, polyimides, and mixtures thereof, and / or d3) 0.5 wt.% to 23 wt.% based on the total weight of the

[0132] Lubricating grease, at least one auxiliary substance.

[0133] In a preferred embodiment, the lubricating grease contains 1 wt.% to 10 wt.%, based on the total weight of the lubricating grease, of at least one solid lubricant (d1). Solid lubricants (d1) can be, in particular, PTFE, metal oxides, metal carbonates, especially calcium carbonate, metal phosphates, graphite, boron nitride, molybdenum disulfide, and mixtures thereof.

[0134] In a further preferred embodiment, the lubricating grease contains 1 wt.% to 10 wt.%, based on the total weight of the lubricating grease, of at least one further thickener (d2) different from b), preferably selected from aluminum simple soaps, calcium sulfonates, bentonites, amorphous silica, hydrophobized amorphous silica, silicates, polyimides, and mixtures thereof. In a further preferred embodiment, the lubricating grease contains 0.5 wt.% to 23 wt.%, based on the total weight of the lubricating grease, of at least one auxiliary agent (d3).

[0135] Auxiliaries can be antioxidants, corrosion inhibitors, high-pressure additives, wear inhibitors, metal deactivators, in particular non-ferrous metal deactivators, for example chelating agents, pour point improvers, VI improvers, radical scavengers, UV stabilizers, reaction layer formers, adhesion improvers, electrical conductivity improvers, in particular ionic liquids, additives for reducing oil separation and mixtures thereof.

[0136] Corrosion protection agents

[0137] The lubricating grease according to the invention may contain at least one corrosion inhibitor as auxiliary agent (d3).

[0138] Corrosion inhibitors neutralize acidic reaction products, e.g., from the oxidation of the base oil or additive degradation. This reduces or prevents corrosive attack. Suitable corrosion inhibitors are the salts of various acids, such as sulfonates, naphthenates, carboxylates, amine phosphates, succinic acid monoesters, or partial polyol esters. The corrosion inhibitor is preferably selected from calcium sulfonates, preferably overbased calcium sulfonates with a base number (TBN) of 100 to 500 mg KOH / g, amine-neutralized phosphates, alkylated calcium naphthalenesulfonates, oxazoline derivatives, imidazole derivatives, succinic acid monoesters, benzotriazole, N-alkylated benzotriazoles, and mixtures thereof.

[0139] The lubricating grease preferably contains at least one corrosion inhibitor d3) in an amount of at least 0.1 wt.%, particularly preferably at least 0.5 wt.%, in particular at least 1.0 wt.%, based on the total weight of the lubricating grease.

[0140] Antioxidants

[0141] TI The lubricating grease according to the invention may contain at least one antioxidant as auxiliary substance (d3).

[0142] Antioxidants increase resistance to aging caused by oxidative and / or thermal stress at the lubrication point. Oxidation can produce acids and oil-insoluble components, which form contaminants that can settle on the lubrication point.

[0143] Suitable antioxidants are aromatic amine antioxidants such as alkylated phenyl-alpha-naphthylamine, dialkyldiphenylamine, aralkylated diphenylamine, sterically hindered phenols such as butylhydroxytoluene (BHT), bis-2,6-di-t-butylphenol derivatives, sulfur-containing hindered phenols, sulfur-containing hindered bisphenol and mixtures thereof.

[0144] The lubricating grease according to the invention preferably contains at least one antioxidant in an amount of at least 0.1% by weight, particularly preferably at least 0.5% by weight, in particular at least 1.0% by weight, based on the total weight of the lubricant composition.

[0145] Metal deactivators

[0146] The lubricating grease according to the invention may contain at least one metal deactivator (additive for protection against metal influences) as auxiliary substance (d3).

[0147] Various metals, such as copper and its compounds, are catalysts for the formation of peroxides and thus contribute to oxidation. Suitable metal deactivators are chelating agents that passivate the metal surface. Non-limiting examples of metal deactivators are triazoles or thiadiazoles, especially aryltriazoles such as benzotriazole and tolyltriazole, alkyl derivatives of such triazoles, and benzothiadiazoles such as R(C6H3)N2S, where R is H or C1- to C10-alkyl. The lubricating grease according to the invention preferably contains at least one metal deactivator in an amount of at least 0.1 wt.%, more preferably at least 0.5 wt.%, in particular at least 1.0 wt.%, based on the total weight of the lubricant composition.

[0148] Wear protection agents

[0149] The lubricating grease according to the invention may contain at least one wear protection agent as auxiliary substance (d3).

[0150] Wear protection agents are used to prevent wear caused by tribological processes, such as fluid and mixed friction

[0151] The antiwear agent is preferably selected from amine-neutralized phosphates, alkylated and non-alkylated triaryl phosphates, alkylated and non-alkylated triaryl thiophosphates, Zn, Mo or W dialkyl dithiophosphates, Zn, Mo or W diaryl dithiophosphates, carbamates, thiocarbamates, Zn, Mo or W dithiocarbamates, dimercaptothiadiazole, organoborates, organophosphites and mixtures thereof.

[0152] The lubricating grease according to the invention preferably contains at least one wear protection agent in an amount of at least 0.1 wt.%, particularly preferably at least 0.5 wt.%, in particular at least 1.0 wt.%, based on the total weight of the lubricant composition.

[0153] Viscosity index improver

[0154] The lubricating grease according to the invention may contain at least one viscosity index improver (VI improver) as auxiliary substance (d3).

[0155] Examples of VI improvers are olefin copolymers, polyalkyl methacrylates, and dispersing olefin copolymers. The lubricating grease according to the invention preferably contains at least one VI improver in an amount of at least 0.1 wt.%, particularly preferably at least 0.5 wt.%, in particular at least 1.0 wt.%, based on the total weight of the lubricant composition.

[0156] Extreme pressure additives

[0157] The lubricating grease according to the invention may contain at least one extreme pressure additive as auxiliary substance (d3).

[0158] Extreme pressure additives act as topcoating agents and / or surfactants. Preferred extreme pressure additives are selected from thiophosphates, such as zinc dithiophosphate, molybdenum oxide sulfide dithiophosphate, molybdenum amine compounds, sulfur compounds, such as sulfurized oils and fats, sulfurized fatty acids, sulfurized fatty acid esters, alkylated polysulfides, and mixtures thereof.

[0159] The lubricating grease according to the invention preferably contains at least one high-pressure additive in an amount of at least 0.1% by weight, particularly preferably at least 0.5% by weight, in particular at least 1.0% by weight, based on the total weight of the lubricant composition.

[0160] Pour point improvers

[0161] The lubricating grease according to the invention may contain at least one poise improver as auxiliary substance (d3).

[0162] Preferred additives for improving the pour point are selected from linear or branched, alkylated, acrylated, and / or aliphatic polymers and copolymers, which can be used individually or in combination. A specific example of a pour point depressant is polyalkyl methacrylate.

[0163] The lubricating grease according to the invention preferably contains at least one pour point

[0164] Improvers in an amount of at least 0.1 wt.%, particularly preferably at least 0.5 wt.%, in particular at least 1.0 wt.%, based on the total weight of the lubricant composition.

[0165] Adhesion improver

[0166] The lubricating grease according to the invention may contain at least one adhesion improver as auxiliary substance (d3).

[0167] Preferred additives for improving adhesion are selected from long-chain polar polymers that give the oil or grease increased adhesion to the surface to be lubricated.

[0168] The lubricating grease according to the invention preferably contains at least one adhesion improver in an amount of at least 0.1% by weight, particularly preferably at least 0.5% by weight, in particular at least 1.0% by weight, based on the total weight of the lubricant composition.

[0169] If present, the proportion of auxiliaries d3) in the lubricating grease according to the invention is preferably 0.5 wt.% to 23 wt.%, more preferably 0.5 wt.% to 20 wt.%, even more preferably 1 wt.% to 18 wt.% and in particular 1.5 wt.% to 12 wt.%, based on the total weight of the lubricating grease. Auxiliaries in the form of phosphorus-, sulfur-containing, nitrogen-containing and / or oxygen-containing compounds, polymers and / or mixtures thereof are preferably used. Particularly preferred auxiliaries are aromatic amines, phenols, in particular alkylated phenols, triazoles such as benzotriazoles, tolyltriazoles, esters, in particular sulfurized fatty acid esters, glycerol mono- or di-esters, sorbitan esters, thiadiazoles, dithiocarbamates, in particular

[0170] Molybdenum dithiocarbamates, phosphates, especially thiophosphates, oligomeric phosphates, oligomeric thiophosphates, dithiophosphates, zinc dialkyldithiophosphates, molybdenum dithiophosphates, amine phosphates, trialkyl phosphates, triaryl phosphates, phosphites, metal salts, carboxylic acids, polymers, especially polymethacrylates, olefin copolymers, and / or mixtures thereof. Particularly preferred auxiliaries d3) are aromatic amines, alkylated phenols, thiadiazoles, dithiocarbamates, triaryl phosphates, amine phosphates, benzotriazoles, and / or mixtures thereof.

[0171] Aromatic amines preferred according to the invention are styrenated diphenylamine, phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, octylated and / or butylated diphenylamine, in particular p,p'-dioctyldiphenylamine, and nonylated diphenylamine. Thus, in a particularly preferred embodiment of the invention, the lubricating grease contains diphenylamine, in particular p,p'-dioctyldiphenylamine, as antioxidants.

[0172] A tribological system is generally a technical system that enables, influences, or prevents movement through contact. Its essential components are the pairs of active surfaces involved in a tribological load and the load collective acting on them. Typically, a tribological system comprises at least one base body that is in contact and moving relative to at least one counter-body. The load collective includes the load applied to the bodies as well as the movement conditions, the friction state, and the temperature. In one embodiment, the lubricating grease according to the invention is located between the two bodies.

[0173] In the context of the invention, a tribological system specifically refers to a system in which friction arises as a result of the relative movement of interacting surfaces, and a lubrication system to minimize wear caused by the stress on the surfaces resulting from friction. The lubricating grease according to the invention reduces wear and ensures the function of parts subject to frictional forces. Typical tribological systems for use with the lubricating grease according to the invention are bearings, chains, compressors, gears, etc.

[0174] The lubricating grease according to the invention is outstandingly suitable as a lubricant, in particular as a lifetime lubricant, in a tribological system. Accordingly, the invention further relates to a tribological system, in particular designed as a bearing, chain, compressor, and / or transmission, containing the lubricating grease according to the invention.

[0175] Preferred embodiments for the tribological system according to the invention include the embodiments described with respect to the lubricating grease according to the invention, mutatis mutandis.

[0176] The lubricating grease according to the invention can be used for a wide variety of bearings, i.e., rolling bearings and / or plain bearings. Preferred rolling bearings and / or plain bearings are selected from radial bearings, axial bearings, radial axial bearings, and / or linear bearings.

[0177] Rolling bearings are particularly preferred because they are particularly suitable for lifetime lubrication. Rolling bearings can be roller bearings or ball bearings. Roller bearings can be needle bearings, cylindrical roller bearings, tapered roller bearings, or spherical roller bearings. Ball bearings can be deep groove ball bearings, angular contact ball bearings, self-aligning ball bearings, and / or thrust ball bearings.

[0178] In a particularly preferred embodiment, the tribological system is designed as a rolling bearing which contains a lubricating grease according to the invention, wherein the lubricating grease has an upper service temperature determined according to DIN 51825:2004-06 at 3000 rpm, 1500 15 N load and installation position B of at least 100°C, preferably from 100°C to 200°C, more preferably from 120°C to 200°C.

[0179] The upper service temperature is reached when at least 50% of a bearing collective (at least 5 test bearings) achieves a running time of at least 100 h at the test temperature.

[0180] In a further specific embodiment of the invention, the lubricating grease according to the invention is used for the lubrication of plain bearings, in particular chains, valves, fittings, in particular gas fittings, actuators, pneumatic cylinders, seals, valves and / or rolling bearings, in particular roller bearings such as needle bearings, cylindrical roller bearings, tapered roller bearings,

[0181] Spherical roller bearings or ball bearings such as deep groove ball bearings, angular contact ball bearings, self-aligning ball bearings and / or thrust ball bearings are used.

[0182] A preferred object is a tribological system lubricated for life with the lubricating grease according to the invention, in particular a bearing, a chain, a compressor and / or a transmission lubricated for life with the lubricating grease according to the invention.

[0183] Also preferred is the use of the lubricating grease according to the invention for the lifetime lubrication of tribological systems, in particular tribological systems in industrial applications and / or automotive applications.

[0184] Preferred embodiments for the uses according to the invention include the embodiments described with respect to the lubricating grease according to the invention, mutatis mutandis.

[0185] The term “lifetime lubricated” or “lifetime lubrication” means that the tribological system is provided with the lubricating grease once and that the lubricating grease does not need to be replaced or renewed until the end of the planned service life.

[0186] The invention further relates to the use of the lubricating grease according to the invention for the lubrication of tribological systems which are in contact with foodstuffs, for example of working equipment in food processing which contains gears, rolling and plain bearings, such as chains for transport in freezing tunnels and conveyor belts, pneumatic cylinders, seals.

[0187] The invention further relates to the use of the lubricating grease according to the invention for lubricating tribological systems which are in contact with drinking water, such as valves and fittings for gas and (drinking) water fittings; and / or for lubricating tribological systems which require application in a temperature range from below -60°C to above 160°C. The invention further relates to the use of the lubricating grease according to the invention for lubricating components in the automotive sector which have rolling or plain bearings, such as ball screw drives in automotive steering applications, actuators;

[0188] Gears, plastic gears, seals, especially seals in sunroofs, brake boosters and / or linear guides.

[0189] The lubricating grease according to the invention is also excellently suited for lubricating the surfaces of sliding components. Its advantageous properties are particularly effective when lubricating the surfaces of sliding components made of steel, non-ferrous metals, and / or plastics.

[0190] Another object of the invention is a method for producing a tribological system in which the lubricating grease according to the invention is introduced between sliding partners moving against each other.

[0191] Preferred embodiments of the methods according to the invention include the embodiments described with respect to the lubricating grease according to the invention.

[0192] Particularly preferred is a lifetime-lubricated tribological system. Also particularly preferred is the tribological system designed as a rolling bearing.

[0193] Preferably, the introduction of the lubricating grease between the sliding partners moving against each other takes place by means of a central lubrication system, an individual lubrication system, preferably a splash lubrication system, injection lubrication, for example by means of a lubricating grease gun and / or a drop feed system.

[0194] The present invention also relates to a process for producing a lubricating grease, preferably a lubricating grease according to one or more of the embodiments described here, comprising the following steps:

[0195] A) Providing a base fat comprising

[0196] A1 ) 50 wt.% to 95.8 wt.%, based on the total weight of the

[0197] Lubricating grease, at least one base oil, A2) 4 wt.% to 20 wt.%, based on the total weight of the lubricating grease, at least one thickener selected from urea thickeners, metal complex soaps, in particular lithium complex soaps, aluminum complex soaps, calcium complex soaps, metal simple soaps of the elements of the first main group of the periodic table, in particular lithium simple soaps and mixtures thereof;

[0198] B) Mixing from 0.2 wt.% to 40 wt.%, based on the total weight of the lubricating grease, at least one semi-crystalline polyalphaolefin having at least one melting peak, measured according to DIN EN ISO 11357-3:2018 above 10°C and a degree of crystallinity of 15% to 45%, wherein the degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin, according to DIN EN ISO 11357-3:2018, and dividing it by 2.93 J / g, into the base grease, thereby obtaining the lubricating grease.

[0199] Preferred embodiments of the process according to the invention include, mutatis mutandis, the preferred embodiments described for the lubricating grease according to the invention. For example, the process may also include the addition of further substances such as additives, solid lubricants, and further thickeners.

[0200] Another object of the present invention is a lubricating grease which is produced by the process according to the invention.

[0201] A further object of the present invention comprises the use of a semi-crystalline polyalphaolefin having at least one melting peak, measured according to DIN EN ISO 11357-3:2018 above 10°C and a degree of crystallinity of 15% to 45%, wherein the degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin, according to DIN EN ISO 11357-3:2018, and dividing it by 2.93 J / g, in combination with a thickener selected from urea thickener, metal complex soaps, in particular lithium complex soaps, aluminum complex soaps, calcium complex soaps, metal simple soaps of the elements of the first main group of the periodic table, in particular lithium simple soaps and mixtures thereof for generating shear stability in lubricating oils and / or for increasing the shear stability of lubricating greases.

[0202] Another object of the present invention comprises a process for the additivation of lubricating oils and / or lubricating greases comprising the introduction of a semi-crystalline polyalphaolefin having at least one melting peak, measured according to DIN EN ISO 11357-3:2018 above 10°C and a degree of crystallinity of 15% to 45%, wherein the degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin, according to DIN EN ISO 11357-3:2018, and dividing it by 2.93 J / g, in combination with a thickener selected from urea thickener, metal complex soaps, in particular lithium complex soaps, aluminum complex soaps, calcium complex soaps, metal simple soaps of the elements of the first main group of the periodic table, in particular lithium simple soaps and mixtures thereof into lubricating oils and / or lubricating greases.

[0203] The process can be used to create shear stability in lubricating oils and / or increase the shear stability of lubricating greases.

[0204] Preferred embodiments of the processes according to the invention comprise preferred embodiments described for the lubricating grease according to the invention, mutatis mutandis.

[0205] Measurement methods

[0206] Determination of the crystallinity of the polyalphaolefin

[0207] The crystallinity of the polyalphaolefin is determined by determining its enthalpy of fusion according to DIN EN ISO 11357-3:2018 and dividing it by 2.93 J / g. Option 1 (linearly interpolated baseline) according to DIN EN ISO 11357-3:2018 is used to determine the baseline. The enthalpy of fusion is determined in the second heating run. If more than one melting event occurs, the enthalpies of fusion determined in this way are summed.

[0208] The invention is explained in more detail below using several non-limiting examples.

[0209] Example 1:

[0210] The crystallinity of two semi-crystalline polyalphaolefins and a paraffin wax is determined. The basic data of the materials investigated are presented in the table below.

[0211] To determine the crystallinity of the substances under investigation, the enthalpy of fusion is first determined using DSC according to DIN EN ISO 11357-3:2018. The following parameters are used:

[0212] - DSC instrument from Netzsch Gerätebau GmbH Phoenix 204 F1

[0213] - Aluminium jar (25 pl) with double perforated lid

[0214] - Sample weight 10 + / - 0.3 mg

[0215] - Temperature program (purge gas N2 with 20 ml / min):

[0216] 1 segment 30°C to -50°C (at 20 K / min)

[0217] 2 segment isothermal at -50°C for 15 min

[0218] 3 segments -50°C to 75°C (at 2 K / min)

[0219] 4 segments 75°C to -50°C (at 20 K / min)

[0220] 5 segment isothermal at -50°C for 15 min

[0221] 6 segments -50°C to 75°C (at 2 K / min)

[0222] For baseline determination, Option 1 (linearly interpolated baseline) according to DIN EN ISO 11357-3:2018 is used. The enthalpy of fusion is determined in the second heating run. Segment 6 is used for the evaluation.

[0223] In Fig. 1 the DSC curves of the substances investigated are shown:

[0224] The parameters determined by DSC are shown in the table below.

[0225] It turns out that the paraffin wax has a crystallinity above 45%.

[0226] Example 2

[0227] Base grease 1 with the composition shown in the table below is prepared using calcium 12-hydroxystearate as a thickener. From this, the non-inventive lubricating grease 1 is produced by adding the polyalphaolefin Vybar® C-6112 (polyalphaolefin 2). In this and all subsequent examples, the semi-crystalline polyalphaolefin is incorporated by mixing at 1500 rpm for 10 minutes using a Hauschild DAC 700.1 FVZ speed mixer, followed by homogenization on a three-roll mill (two rolling passes). Both the base grease and the lubricating grease are tested for dropping point and oil separation, and their cone penetration is measured (comparing fresh grease and grease after rolling). The results are shown in the table below.

[0228] It is shown that the addition of the semi-crystalline polyalphaolefin to the calcium simple soap thickened base grease reduces the shear stability of the base grease.

[0229] Example 3

[0230] Base grease 2 with the composition shown in the table below is prepared using calcium 12-hydroxystearate as a thickener. Non-inventive lubricating grease 2 is then prepared from this by adding semi-crystalline polyalphaolefin 2 (Vybar® C-6112). Both the base grease and the lubricating grease are tested for dropping point, oil separation, and their cone penetration (comparing fresh grease and flexed grease) is measured. The results are shown in the table below.

[0231]

[0232] It is shown that the addition of the semi-crystalline polyalphaolefin to the calcium simple soap thickened base fat leads to a strong softening in both the fresh fat and the milling experiment.

[0233] Example 4

[0234] Base grease 3 with the composition shown in the table below is prepared using calcium 12-hydroxystearate as a thickener. Non-inventive lubricating grease 3 is then prepared from this by adding the semi-crystalline polyalphaolefin Vybar® C-6112. Both the base grease and the lubricating grease are tested for dropping point, oil separation, and their cone penetration (comparing fresh grease and flexed grease) is measured. The results are shown in the table below.

[0235] It is shown that the addition of the semi-crystalline polyalphaolefin leads to a reduction in the dropping point.

[0236] Example 5

[0237] Base grease 4 with the composition shown in the table below is prepared using a lithium complex soap, and the inventive lubricating grease 4 is then added to this base grease by adding the polyalphaolefin Vybar® C-6112. Both the base grease and the lubricating grease are tested for dropping point, oil separation, and their cone penetration (comparing fresh grease and flexed grease) is measured. The results are shown in the table below.

[0238] It turns out that the addition of the semi-crystalline polyalphaolefin to base grease 4, which contains a lithium complex soap, surprisingly leads to lower penetration of the inventive grease than fresh grease, and also reduces oil separation. Even in the Shell Roll Test, the milled grease shows a hardening effect compared to fresh grease. Base grease 4, in contrast, shows a softening effect. The hardening of the inventive grease 4 in the Shell Roll test is particularly surprising because, given the low initial penetration, a rather greater softening effect was to be expected.

[0239] Example 6

[0240] Base grease 5 with the composition shown in the table below is prepared using a urea thickener, and the inventive lubricating grease 5 is obtained from this by adding the semi-crystalline polyalphaolefin 2 (Vybar® C-6112). Both the base grease and the lubricating grease are tested for dropping point, oil separation, and their cone penetration (comparing fresh grease and grease after flexing) is measured. The results are shown in the table below.

[0241]

[0242] It turns out that the addition of the semi-crystalline polyalphaolefin to the base grease 5 surprisingly leads to a significant reduction in the softening of the urea grease in the Shell Roll Test.

[0243] Example 7

[0244] The base grease 6 is prepared with the composition shown in the table below using a lithium complex soap as a thickener, and from this the lubricating grease 6 according to the invention is prepared by adding the semi-crystalline polyalphaolefin 2, Vybar® C-6112. Both the base grease and the lubricating grease are examined with regard to dropping point, oil separation and their cone penetration (comparative fresh grease and grease after rolling) is measured.

[0245] The results are shown in the table below.

[0246] It turns out that the addition of the polyalphaolefin to the base grease 6 surprisingly leads to a reduction in the softening of the lithium complex soap thickened grease in the Shell Roll Test.

[0247] Example 8

[0248] The lithium simple soap grease has a lithium 12-hydroxystearate content of

[0249] 8.6 wt% and 1 wt% amine antioxidant, The base oil is a mixture of PAO 4 and mPAO 300, the kinematic viscosity at 40°C is 1000 mm 2 / s.

[0250] The non-inventive grease 8b, which does not contain any semi-crystalline polyalphaolefin, exhibits a softening of 63 units in the Shell Roll Test. The inventive compositions 8a, 8c-8k, which contain the semi-crystalline polyalphaolefins individually or in combination and in different concentrations, exhibit lower softening in the Shell Roll Test in all cases. For example, a comparison of 8i with 8a shows that the semi-crystalline polyalphaolefin 2 (Vybar® C 6112) has significantly greater effects in this base grease than the semi-crystalline polyalphaolefin 1 (Vybar™ 260). By appropriately selecting the amounts used, the softening can be controlled and, for example, adjusted to almost 0, see 8k.

[0251] Example 9

[0252] Aluminum complex grease (11% thickener content, containing benzoic acid and stearic acid as acid components), base oil PAO 6.

[0253] The non-inventive grease 9e, which does not contain a semi-crystalline polyalphaolefin, exhibits a softening of 64 units in the Shell Roll Test. The inventive compositions 9a - 9d, which contain the semi-crystalline polyalphaolefins individually or in combination and in different concentrations, exhibit lower softening in all cases in the Shell Roll Test. In this grease concept, the two semi-crystalline polyalphaolefins are similarly effective (cf. 9b and 9c).

[0254] Example 10. Comparison of partially crystalline PAO with paraffin wax

[0255] A lithium soap grease was used as the base grease, with lithium 12-hydroxystearate content: 8.6%), 1% amine antioxidant, base oil mixture PAO 4 and mPAO 300, kinematic viscosity at 40°C 1000 mm 2 / s.

[0256] The softening after the test over 50 h is significantly increased for the non-inventive paraffin wax (mixture 1 b) compared to the starting material (10c), while the inventive sample 10a has a significantly lower softening.

[0257] Example 11

[0258] Base grease 11 with the composition shown in the table below is prepared using a calcium complex soap as a thickener. From this, the inventive lubricating grease 11 is prepared by adding the semi-crystalline polyalphaolefin 2 (Vybar® C-6112). Both the base grease and the lubricating grease 11 are tested for dropping point, oil separation, and their cone penetration (comparing fresh grease and grease after flexing) is measured. The results are shown in the table below.

[0259]

Claims

Patent claims 1 . Lubricating grease containing a) 50 wt.% to 95.8 wt.%, based on the total weight of the lubricating grease, of at least one base oil, b) 4 wt.% to 20 wt.%, based on the total weight of the lubricating grease, of at least one thickener selected from urea thickeners, metal complex soaps, in particular lithium complex soaps, aluminum complex soaps, calcium complex soaps, metal simple soaps of the elements of the first main group of the periodic table, in particular lithium simple soaps and mixtures thereof, c) 0.2 wt.% to 40 wt.%, based on the total weight of the lubricating grease, of at least one semi-crystalline polyalphaolefin having at least one melting peak, measured according to DIN EN ISO 11357-3:2018 above 10°C and a degree of crystallinity of 15% to 45%, wherein the degree of crystallinity of the semi-crystalline polyalphaolefin is determined by determining the enthalpy of fusion of the semi-crystalline polyalphaolefin determined according to DIN EN ISO 11357-3:2018 and divided by 2.93 J / g.

2. Lubricating grease according to claim 1, characterized in that the proportion of the base oil a) is 50 wt.% to 92 wt.%, based on the total weight of the lubricating grease, and the lubricating grease d) contains 0.5 wt.% to 43 wt.%, based on the total weight of the lubricating grease, at least one additive different from b) and c), in particular at least one solid lubricant (d1), at least one further thickener (d2) and / or at least one auxiliary substance (d3).

3. Lubricating grease according to claim 1 or 2, characterized in that the Proportion of the base oil a) is 50 wt.% to 92 wt.%, based on the total weight of the lubricating grease, and the lubricating grease d) 0.5 wt.% to 43 wt.%, based on the total weight of the lubricating grease, contains at least one further additive different from b) and c), comprising d1 ) 1 wt.% to 10 wt.%, based on the total weight of the lubricating grease, at least one solid lubricant, and / or d2) 1 wt.% to 10 wt.%, based on the total weight of the Lubricating grease, at least one further thickener, preferably selected from aluminum simple soaps, calcium sulfonates, bentonites, amorphous silica, hydrophobized amorphous silica, silicates, polyimides and mixtures thereof, and / or d3) 0.5 wt.% to 23 wt.%, based on the total weight of the Lubricating grease, at least one auxiliary agent, preferably selected from antioxidants, corrosion inhibitors, high-pressure additives, wear inhibitors, metal deactivators, in particular non-ferrous metal deactivators, for example chelating agents, pour point improvers, VI improvers, radical scavengers, UV stabilizers, Reaction layer formers, adhesion improvers, electrical conductivity improvers, additives to reduce oil separation and mixtures thereof.

4. Lubricating grease according to one or more of the preceding claims, characterized in that the semi-crystalline polyalphaolefin has an acid number according to ASTM D664-18e1 of 10 mg KOH / g to 120 mg KOH / g, preferably of 40 mg KOH / g to 100 mg KOH / g.

5. Lubricating grease according to one or more of the preceding claims, characterized in that the semi-crystalline polyalphaolefin has a molecular weight Mn, measured according to DIN 55672-1:2016-03 of more than 2500 g / mol, for example from 2500 g / mol to 37000 g / mol, more preferably from 2500 g / mol to 5600 g / mol, in particular from Mn 3000 g / mol to Mn 5600 g / mol.

6. Lubricating grease according to one or more of the preceding claims, characterized in that the viscosity of the semi-crystalline polyalphaolefin at 100°C is between 30 cPs and 1800 cPs, preferably between 80 cPs and 220 cPs, measured according to ASTM D3236-15(2021).

7. Lubricating grease according to one or more of the preceding claims, characterized in that the amount of the semi-crystalline polyalphaolefin is in the range from 1 wt.% to 25 wt.%, more preferably in the range from 3 wt.% to 20 wt.%, in particular in the range from 3 wt.% to 10 wt.%.

8. Lubricating grease according to one or more of the preceding claims, characterized in that the thickener b) is selected from urea thickeners, lithium complex soaps, lithium simple soaps and mixtures thereof.

9. Lubricating grease according to one or more of the preceding claims, characterized in that the base oil is selected from esters, ethers, synthetic hydrocarbons, preferably polyalphaolefin base oil, in particular metallocene-catalyzed polyalphaolefin base oil and mixtures thereof.

10. Lubricating grease according to one or more of the preceding claims, characterized in that the base oil is a polyalphaolefin base oil with a kinematic viscosity, determined according to ASTM-D-7042, September 2014 edition, at 40°C of 10 mm 2 / s up to 15000 mm 2 / s, preferably 15 mm 2 / s up to 10000 mm 2 / s, especially 15 mm 2 / s up to 1300 mm 2 / s.

11. A method for producing a tribological system, characterized in that a lubricating grease according to one or more of the preceding claims is introduced between sliding partners moving relative to one another.

12. Method according to claim 11, characterized in that the introduction of the lubricating grease between the sliding partners moving against each other is carried out by means of a central lubrication system, an individual lubrication system, preferably a splash lubrication system, injection lubrication, for example by means of a lubricating grease gun and / or a drop feed system.

13. Tribological system, in particular designed as a bearing, chain, compressor and / or gear, which contains a lubricating grease according to one or more of claims 1 to 10.

14. Tribological system according to claim 13, characterized in that it is designed as a rolling bearing.

15. Tribological system according to claim 13 or 14, characterized in that it is designed as a ball screw drive in automotive steering applications, actuators, gears, plastic gears, seals, seals in sunroofs, brake boosters and / or linear guides.

16. Tribological system according to claim 14, characterized in that the lubricating grease has an upper service temperature determined according to DIN 51825:2004-06 at 3000 rpm, 1500 15 N load and installation position B of at least 100°C, preferably from 100°C to 200°C, more preferably from 120°C to 200°C.

17. Use of a lubricating grease according to one or more of claims 1 to 10 for lubricating the surfaces of sliding partners, in particular for the lifetime lubrication of tribological systems, in particular tribological systems in industrial applications and / or automotive applications.

18. Use of a lubricating grease according to one or more of claims 1 to 10 for the lubrication of components in the automotive sector which have rolling or plain bearings, such as ball screws in automotive steering applications, actuators; gears, plastic gears, seals, Seals in sunroofs, brake boosters and / or linear guides.

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