Lubricant free of mineral oil and production method for lubricant free of mineral oil
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- KAJO GMBH
- Filing Date
- 2024-06-06
- Publication Date
- 2026-05-25
AI Technical Summary
Current calcium sulfonate greases based on mineral oils or synthetic base oils are not biodegradable, and the production process requires additional solubilizers and filtration steps due to incomplete dispersion, which are costly and inefficient.
A method to produce calcium sulfonate grease using an ester-based composition, converting overbased calcium sulfonate from vaterite to calcite form, eliminating mineral oil and ensuring complete dispersion without the need for solubilizers or filtration, by controlling the base number and water content during the production process.
The resulting lubricant is completely biodegradable, meets OECD-301 test requirements, remains fluid at low temperatures, and has high pressure absorption capacity, eliminating the need for additional processing steps and reducing costs.
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Abstract
Description
[Technical field]
[0001] 2. Background of the Invention The present invention relates to a method for producing a lubricant in which an overbased calcium sulfonate is first produced or provided, which is then converted from a vaterite form to a calcite form, and finally a calcium sulfonate grease is produced by heating the mixture. The present invention further relates to lubricants produced according to this method, and to lubricants comprising at least one ester composition, calcium carbonate, and at least one overbased alkylbenzene sulfonate. [Background technology]
[0002] prior art Lubricants or lubricants are used for friction and wear reduction, vibration damping, sealing and anticorrosive protection of tools, machines, engines, automobiles, aircraft, ships and their parts. In this case, a distinction is made between liquid (lubricating oils), pasty (lubricating greases) and solid (solid lubricants such as graphite). Lubricating greases usually consist of lubricating oils, thickeners, auxiliaries and additional substances (additives). Lubricating greases usually contain about 80% lubricating oil, 5-10% thickeners and 10-15% additives. In this case, mineral oils, natural or synthetic ester oils, polyalphaolefins or silicon oils, etc. can be used as lubricating oils. Synthetic ester oils include, for example, mono- and di-carboxylic acid esters, polyol esters and complex esters. Apart from various soaps and inorganic substances (such as bentonite), calcium sulfonates are often used as thickeners, which, in addition to their thickening action in greases, also have a corrosion inhibitory effect due to their alkaline nature.
[0003] Calcium sulfonate greases currently on the market are based exclusively on mineral oil or synthetic base oils such as polyalphaolefins (PAOs). In this case, mineral oil and PAOs make up up to 80% of the grease. The core component for producing calcium sulfonate greases is the so-called overbased calcium sulfonate, which is represented by the reaction of alkylbenzene sulfonic acid with calcium hydroxide and calcium oxide by the introduction of carbon dioxide into a mineral carrier oil. Commercially available overbased calcium sulfonates usually contain more than 50% mineral oil. It is not possible to produce rapidly biodegradable calcium sulfonate greases using these components. Since complete dispersion of calcium sulfonate is usually not achieved completely in mineral oils or PAOs, solubilizers such as water, organic solvents or acids are added, which have to be removed again after production. Filtration is often also required to remove undispersed solid particles.
[0004] "Biodegradable" is understood to mean the decomposition of a lubricant with the help of microorganisms into inorganic substances such as water, salts, carbon dioxide and biomass. According to the current state of the art, the complete biodegradability of a lubricant is determined only by the OECD-301 test method based on CO2 production. Biodegradability is determined at the end of a "10-day test window" and after a 28-day test period. If a lubricant has achieved the required degree of decomposition of at least 60% at the end of the 10-day window and after 28 days of incubation, it is classified as "readily biodegradable" and is awarded, for example, the EU Ecolabel (EEL).
[0005] WO2004 / 106474A1 describes lubricants with improved biodegradability, based for example on polyol esters (C5-C8) or polyalkylene glycols, calcium sulfonate-based thickeners, and biodegradable oils such as naturally occurring phospholipids. However, in this case a mixture of mineral oil-based overbased magnesium and calcium sulfonates is used as thickener. Due to the non-low content of mineral oil, the lubricants described in WO2004 / 106474A1 do not allow complete biodegradability according to OECD-301. Summary of the Invention [Problem to be solved by the invention]
[0006] Description of the invention It is an object of the present invention to provide a method for producing a lubricant that does not require the use or addition of mineral oil, and to produce a lubricant that is completely biodegradable. [Means for solving the problem]
[0007] This problem is solved according to the invention by a method for producing a lubricant comprising the steps of: a) Preparation of an overbased calcium sulfonate comprising the steps of: - at least one mono-, di-, or tri-alkylbenzenesulfonic acid, at least one alkyl group of which is a (C3-C30)-alkyl group, is dissolved in at least one ester composition, where the ester composition comprises at least one ester; -Mixture of calcium hydroxide and calcium oxide; - heating the mixture to a temperature in the range of 30°C to 90°C, introducing carbon dioxide into the mixture, and adjusting the mixture to a base number (TBN) of up to 550 mg KOH / g; b) converting an overbased calcium sulfonate from a vaterite form to a calcite form, comprising the steps of: -Adjusting the mixture to a moisture content in the range of 2% to 20% by weight; - heating the mixture to a temperature in the range of 80°C to 105°C, where the mixture is adjusted to a base number of 450 mg KOH / g or less; and c) Preparation of a calcium sulfonate grease by heating the mixture to a temperature in the range of 90°C to 200°C.
[0008] The method according to the invention is particularly characterized in that both the calcium sulfonate and the grease containing said calcium sulfonate are produced exclusively on an ester basis, so that the final product is free of mineral oil and therefore easily and completely biodegradable. The lubricant according to the invention achieves the required 60% degree of degradation at the end of the so-called 10-day window and also after 28 days, thereby meeting the requirements of the OECD-301 test method. Furthermore, the replacement of mineral oil with organic or synthetic esters means that the addition of solubilizers can be omitted, thus eliminating the need to remove them in an expensive manner at the end of the production process. The method according to the invention further ensures that the overbased calcium sulfonate in the reaction mixture is completely dispersed, so that filtration can also be omitted at the end of the process.
[0009] According to the invention, the conditions for producing the lubricant are selected such that the ester composition is not decomposed under these conditions. For this purpose, the base number (TBN = total base number), which is a measure of the basicity of the reaction mixture, i.e. the ability of the substances contained in the mixture to neutralize acids, is determined during the process. The unit [mg KOH / g] in this case relates to the basicity of potassium hydroxide (KOH). According to the invention, the basicity of the mixture in step a) is limited to a TBN of not more than 550 mg KOH / g and in step b) to a TBN of not more than 450 mg KOH / g. Monitoring and regulating or limiting the basicity of the mixture advantageously results in that the esters are not saponified in the mixture, even under the influence of high temperatures, especially in steps b) and c). The moderate addition of water also contributes to this. Adjusting the mixture in step b) to a water content in the range of 2% to 20% by weight significantly reduces the possibility of hydrolysis of the esters. Choosing the lowest possible temperature, especially in steps a) and b), is also advantageous in that the esters remain stable in the mixture. In this way, mineral oil-free, biodegradable calcium sulfonate greases can be produced in a particularly advantageous manner.
[0010] At least one alkyl group of the mono-, di- or tri-alkylbenzenesulfonic acid may be a linear, branched and / or cyclic alkyl group. In an advantageous embodiment of the invention, it is provided that in this case at least one alkyl group of the mono-, di- or tri-alkylbenzenesulfonic acid is a (C10-C18)-alkyl group.
[0011] The ester composition may, for example, comprise synthetic esters and / or natural (organic) esters. Suitable esters are, for example, mono- and dicarboxylic acid esters, polyol esters and complex esters, but also natural ester oils, such as, for example, rapeseed oil. The ester composition in this case may consist of an ester or a mixture of two or more different esters. The viscosity of the ester composition is preferably less than 2 mm. 2 / s~1200mm 2 / s, preferably 10 mm 2 / s~500mm 2 / s.
[0012] Advantageous embodiments of the invention further provide that the mixture of step a) is adjusted to a base number (TBN) in the range of 150 to 550 mg KOH / g, preferably 210 to 450 mg KOH / g or 320 to 420 mg KOH / g, in particular 211 to 399 mg KOH / g. Alternatively, the base number of the mixture of step a) can be adjusted to a TBN in the range of 200 to 500 mg KOH / g or 300 to 500 mg KOH / g or 400 to 500 mg KOH / g or 150 to 450 mg KOH / g or 250 to 450 mg KOH / g or 350 to 450 mg KOH / g or 200 to 400 mg KOH / g or 300 to 400 mg KOH / g.
[0013] A further advantageous embodiment of the invention provides that the mixture of step b) is adjusted to a base number (TBN) in the range of 50 to 450 mg KOH / g, preferably 70 to 350 mg KOH / g or 100 to 250 mg KOH / g, in particular 80 to 220 mg KOH / g. Alternatively, the base number of the mixture of step b) can be adjusted to a TBN in the range of 100 to 450 mg KOH / g or 200 to 450 mg KOH / g or 300 to 450 mg KOH / g or 350 to 450 mg KOH / g or 50 to 300 mg KOH / g or 100 to 300 mg KOH / g or 200 to 300 mg KOH / g or 150 to 250 mg KOH / g.
[0014] A further advantageous embodiment of the invention provides that the mixture of step a) is heated to a temperature in the range of 35°C to 85°C or 45°C to 60°C, in particular 40°C to 82°C. Alternatively, the mixture of step a) can be heated to a temperature in the range of 45°C to 85°C or 55°C to 85°C or 65°C to 85°C or 75°C to 85°C or 40°C to 70°C or 50°C to 70°C or 60°C to 70°C or 50°C to 80°C or 55°C to 75°C. A further advantageous embodiment of the invention provides that the mixture of step b) is heated to a temperature in the range of 87°C to 102°C or 85°C to 100°C, in particular 88°C to 99°C. Alternatively, the mixture of step b) can be heated to a temperature in the range of 90°C to 102°C or 95°C to 102°C or 87°C to 100°C or 90°C to 100°C.
[0015] Further advantageous embodiments of the invention provide that the mixture of step c) is heated to a temperature in the range of 100° C. to 180° C. or 110° C. to 170° C., in particular 125° C. to 160° C. Alternatively, the mixture of step c) can be heated to a temperature in the range of 120° C. to 180° C. or 130° C. to 180° C. or 140° C. to 180° C. or 150° C. to 180° C. or 160° C. to 180° C. or 150° C. to 170° C. or 100° C. to 160° C. or 110° C. to 160° C. or 120° C. to 160° C. or 130° C. to 160° C. or 140° C. to 160° C. or 170° C. to 180° C.
[0016] An advantageous embodiment of the invention further provides that the water content of the mixture in step b) is adjusted to a content in the range of 5% to 18% by weight, in particular 7% to 15% by weight. Alternatively, the water content of the mixture in step b) can also be adjusted to a content in the range of 5 to 15% by weight, or 10-15% by weight, or 7-18% by weight, or 10-18% by weight, or 9-13% by weight.
[0017] In order to adjust the basicity of the reaction mixture of step b) to the desired TBN, calcium hydroxide and / or at least one mono-, di- or tri-alkylbenzenesulfonic acid, where at least one alkyl group is a (C3-C30) alkyl group, and / or at least one ester composition, where the ester composition comprises at least one ester, can be mixed into the mixture. Furthermore, by adding one or more of the aforementioned substances, the conversion of the vaterite form to the calcite form can be positively influenced in terms of the completeness of the conversion.
[0018] To further improve the properties of the lubricant according to the invention, additional auxiliary materials and / or additives can be mixed into the reaction mixture. For example, acetic acid can be added, preferably in step b), to adjust the desired basicity if necessary, to achieve an increase in the dropping point with the resulting calcium acetate. Furthermore, preferably following the conversion to the calcite form, 12-hydroxystearic acid can be mixed in to optimize the lubricant with respect to its hydrophobicity, i.e. its ability to resist water. To be able to further improve the anticorrosive protection of the lubricant, phenolic antioxidants (e.g. Irganox® L 107, BASF), amine antioxidants (e.g. Irganox® L 57, BASF) and / or dimercaptothiadiazole derivatives (ADDITIN® RC 8213 (Lanxess)) can be added. In principle, all usual additives that improve the consistency and properties of the lubricant according to the invention can be added.
[0019] The present invention further relates to a lubricant produced by the method according to the present invention described above. The lubricant according to the present invention is free of mineral oil and is therefore easily biodegradable according to the requirements of the OECD-301 test method. In addition, unlike mineral oil-containing lubricating greases, it remains fluid even at very low temperatures (-10°C to -20°C) and has a high pressure absorption capacity.
[0020] This problem is further solved by a mineral oil-free lubricant comprising at least one ester composition comprising at least one ester, calcium carbonate, and at least one overbased mono-, di-, or tri-alkylbenzene sulfonate, where at least one alkyl group of the mono-, di-, or tri-alkylbenzene sulfonate is a (C3-C30) alkyl group. The lubricant according to the invention is easily biodegradable according to the requirements of the OECD-301 test method, since it is free of mineral oil and contains only esters as oil components. Since it contains only esters, not mineral oil, the lubricant according to the invention is fluid even at very low temperatures (-10°C to -20°C) and also has a very high pressure absorption capacity.
[0021] At least one alkyl group of the mono-, di- or tri-alkylbenzenesulfonate can be a linear, branched and / or cyclic alkyl group. In an advantageous embodiment of the invention, it is provided that in this case at least one alkyl group of the mono-, di- or tri-alkylbenzenesulfonate is a (C10-C18) alkyl group.
[0022] The ester composition may, for example, comprise synthetic esters and / or natural (organic) esters. Examples of suitable esters are mono- and dicarboxylic esters, polyol esters and complex esters, but also natural ester oils, such as rapeseed oil. The ester composition in this case may consist of an ester or a mixture of two or more different esters. The ester composition is preferably 2 mm 2 / s to 1200mm 2 / s range, preferably 10 mm 2 / s to 500mm 2 The viscosity should be in the range of 0.1 to 1.0 μm / s.
[0023] In an advantageous embodiment of the invention, a mineral oil-free lubricant is provided comprising from 30% to 80% by weight of an ester composition, from 5% to 20% by weight of calcium carbonate and from 5% to 25% by weight of an overbased mono-, di- or tri-alkylbenzene sulfonate.
[0024] A particularly advantageous embodiment of the present invention provides that the mineral oil-free lubricant comprises 50% to 65% by weight of the ester composition, 10% to 15% by weight of calcium carbonate and 12% to 20% by weight of an overbased mono-, di-, or tri-alkylbenzene sulfonate.
[0025] Furthermore, the lubricant according to the invention may contain additives, examples of which are phenolic antioxidants (e.g. Irganox® L 107, BASF), amine antioxidants (e.g. Irganox® L 57, BASF) and / or dimercaptothiadiazole derivatives (ADDITIN® RC 8213 (Lanxess)).
[0026] Exemplary compositions of advantageous embodiments of lubricants according to the present invention are specified in Table 1.
[0027] [Table 1]
[0028] Further advantages and features of the present invention will become apparent from the drawings and the following examples which show exemplary and preferred embodiments of the invention. [Brief description of the drawings]
[0029] Brief explanation of the figure [Figure 1]Figure 1 shows the formation of overbased calcium sulfonate, where calcium carbonate micelles are first formed from calcium hydroxide, calcium oxide, and CO2, and then alkylbenzene sulfonate salts bearing polar groups are attached. The non-polar (lipophilic) alkyl residues in this case are oriented outward, surrounding the CaCO3 micelles, allowing them to be completely dispersed in the base oil (ester composition). [Diagram 2] FIG. 2 shows the structure of overbased calcium sulfonate after addition of Ca(OH)2. [Diagram 3] FIG. 3 shows the structure of a mixture of overbased calcium sulfonate, Ca(OH)2, benzoic sulfonic acid (dialkyl or monoalkyl, C10-C18), and acetic acid. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Description of exemplary and preferred embodiments of the present invention The following examples represent illustrative embodiments of the method according to the invention, the features described or shown therein may represent subject matter of the invention individually or in any combination, unless clearly to the contrary from the above description.
[0031] Example 1: 284 g of benzenesulfonic acid C10-18-alkyl derivative was added to 500 g of bis(2-ethylhexyl) sebacate (V40: 10 mm 2 / s). Then, 10 g of calcium hydroxide is added and the mixture is stirred at 50 °C for 30 minutes. Then, 133 g of calcium oxide and 115 g of Ca(OH)2 are added and the mixture is homogenized by further stirring. Then, the temperature is increased to 60 °C. Then, 110 ml of water is added and carbon dioxide is passed through the mixture. The mixture has a TBN of 367 mg KOH / g. Then, 300 g of bis(2-ethylhexyl) sebacate, 200 g of benzenesulfonic acid C10-18-alkyl derivative and 120 g of water are added to the formulation. The formulation is heated to 99 °C. After converting the calcium carbonate from vaterite to the calcite form, the formulation is dehydrated at 110 °C. The TBN is now about 162 mg KOH / g. Then, the formulation is heated to 160 °C and maintained at this temperature for 1 hour. After cooling, the grease has a consistency of 331 mm / 10 after 60 double strokes (according to ASTM D217). Further technical data can be taken from Table 2.
[0032] Example 2: 280 g of benzenesulfonic acid C10-14-alkyl derivative was mixed with 700 g of complex ester (fatty acid, C18-unsaturated, dimerized, polymer containing 2-ethylhexanol and neopentyl glycol) (V40: 110.5 mm 2 / s). Then, 11 g of calcium hydroxide is added and stirred at 50°C for 45 minutes. Then, 151 g of calcium oxide and 151 g of Ca(OH)2 are added and the mixture is homogenized by stirring. Then, the temperature is increased to 82°C. Then, 130 g of water is added and carbon dioxide is passed through the mixture. The mixture now has a TBN of 399 mg KOH / g. 300 g of complex ester (fatty acid, C18-unsaturated, dimerized, polymer with 2-ethylhexanol and neopentyl glycol), 220 g of C10-14-alkyl benzenesulfonate, 21 g of acetic acid, 72 g of Ca(OH)2 and 180 g of water are added to the formulation. The formulation is heated to 92°C. After the calcium carbonate is converted from the vaterite form to the calcite form, the formulation is dehydrated at 110°C. Now the TBN is about 220 mg KOH / g. The formulation is then heated to 160°C and maintained at this temperature for 1 hour. After cooling, the grease has a consistency of 292mm / 10 after 60 double strokes (according to ASTM D217). Further technical data are available in Table 2.
[0033] Example 3: 280 g of benzenesulfonic acid C10-14-alkyl derivative was mixed with 500 g of neopentyl glycol diisostearate (saturated ester) (V40: 48 mm 2The mixture is dissolved in 100 ml of water (1000 mg KOH / g). 11 g of calcium hydroxide is then added and stirred at 50°C for 45 minutes. 151 g of calcium oxide and 131 g of Ca(OH)2 are then added and further stirred to homogenize the mixture. The temperature is then increased to 62°C. 130 ml of water is then added and carbon dioxide is passed through the mixture. The mixture now has a TBN of 369 mg KOH / g. Then, 300 g of neopentyl glycol diisostearate (saturated ester, 243 g of C10-14-alkyl benzenesulfonate, 21 g of acetic acid, 72 g of Ca(OH)2 and 65 g of water are added to the formulation. The formulation is heated to 92°C. After converting the calcium carbonate from vaterite to calcite form, the formulation is dehydrated at 110°C, where the TBN is approximately 188 mg KOH / g. The formulation is then heated to 160°C and maintained at this temperature for 1 hour. After cooling, the grease has a consistency of 272 mm / 10 after 60 double strokes (according to ASTM D217). Detailed technical data can be taken from Table 2.
[0034] Example 4: 260g of C10-18-alkyl benzenesulfonate and 1000g of complex ester (pentaerythritol sebacic acid isostearic acid copolymer) (V40: 1200mm 2 100 g of calcium hydroxide is then added and stirred at 50°C for 30 minutes. 101 g of calcium oxide and 104 g of Ca(OH)2 are then added and further stirred to homogenize the mixture. The temperature is then increased to 60°C. 130 ml of water is then added and carbon dioxide is passed through the mixture. The TBN of the mixture is 335 mg KOH / g. 400 g of bis(2-ethylhexyl) sebacate (V40: 12.5 mm 2270 g of C10-14-alkyl benzenesulfonate, 75 g of Ca(OH)2 and 195 g of water are added to the formulation. The formulation is heated to 92°C. After converting the calcium carbonate from vaterite to calcite, 150 g of 12-hydroxystearic acid are added and the formulation is dehydrated at 110°C. The TBN is then about 159 mg KOH / g. The formulation is subsequently heated to 160°C and maintained at this temperature for 1 hour. After cooling, the grease has a consistency of 261 mm / 10 (according to ASTM D217) after 60 double strokes. Further technical data can be taken from Figure 2.
[0035] Example 5: 300g of C10-18-alkyl benzenesulfonate was mixed with 550g of trimethylolpropane trioleate (V40: 46mm 2 / s). Then, 120 g of calcium oxide and 100 g of Ca(OH)2 are added and the mixture is homogenized by further stirring. Then, the temperature is raised to 60 ° C. Then, 80 ml of water are added and carbon dioxide is passed through the mixture. The TBN of the mixture is now 297 mg KOH / g. Then, 280 g of trimethylolpropane trioleate, 280 g of C10-14-alkyl benzenesulfonate, 72 g of Ca(OH)2 and 75 g of water are added to the formulation. The formulation is heated to 92 ° C. After the calcium carbonate is converted from the vaterite type to the calcite type, the formulation is dehydrated at 110 ° C. The TBN is about 180 mg KOH / g. Then, the formulation is heated to 150 ° C and kept at this temperature for 30 minutes. After cooling, the grease has a consistency of 299 mm / 10 after 60 double strokes (according to ASTM D217). Further technical data is available in Table 2.
[0036] Example 6: 310 g of C8-C22-alkyl benzenesulfonate mixed with 550 g of trimethylolpropane trioleate (V40: 46 mm 2 / s). Then, 120 g of calcium oxide and 100 g of Ca(OH)2 are added and the mixture is homogenized by further stirring. Then, the temperature is increased to 60°C. Then, 80 ml of water is added and carbon dioxide is passed through the mixture. The TBN of the mixture is now 297 mg KOH / g. Then, 280 g of trimethylolpropane trioleate, 254 g of C8-C22-alkyl benzenesulfonate, 75 g of Ca(OH)2, 25 g of acetic acid and 70 g of water are added to the formulation. The formulation is heated to 92°C. After the calcium carbonate is converted from the vaterite form to the calcite form, the formulation is dehydrated at 110°C and 100 g of caproic acid are added. The TBN is now about 161 mg KOH / g. Then, the formulation is heated to 150°C and maintained at this temperature for 30 minutes. After cooling, the grease has a consistency of 287 mm / 10 after 60 double strokes (according to ASTM D217). Further technical data can be found in Table 2.
[0037] Example 7: 322 g of C10-18-alkyl benzenesulfonate in 600 g of rapeseed oil (V40: 35 mm 2 The mixture is then dissolved in 200 g of ethanol (V40: 35 mm TBN). 140 g of calcium oxide and 80 g of Ca(OH)2 are then added and further stirred to homogenize the mixture. The temperature is then increased to 40°C. 62 ml of water are then added and carbon dioxide is passed through the mixture. The TBN of the mixture is now 211 mg KOH / g. Then 240 g of rapeseed oil (V40: 35 mm TBN) is added. 2 288 g of C10-14-alkyl benzenesulfonate, 24 g of acetic acid, 70 g of Ca(OH)2, and 49 g of water are added to the formulation. The formulation is heated to 88°C. After converting the calcium carbonate from the vaterite type to the calcite type, 167 g of 12-hydroxystearic acid are added and the formulation is dehydrated at 110°C. The TBN is then about 80 mg KOH / g. The formulation is subsequently heated to 125°C and maintained at this temperature for 15 minutes. After cooling, the grease has a consistency of 299 mm / 10 (according to ASTM D217) after 60 double strokes. Further technical data can be taken from Table 2.
[0038]
Table 2
[0039]
Claims
1. A mineral oil-free biodegradable grease comprising at least one ester composition containing at least one ester and no mineral oil, calcium carbonate, and at least one overbasic mono-, di-, or tri-alkylbenzenesulfonate, wherein at least one alkyl group of the mono-, di-, or tri-alkylbenzenesulfonate is a (C3-C30)-alkyl group, A biodegradable grease in which calcium carbonate is surrounded by an overbasic mono-, di-, or tri-alkylbenzene sulfonate.
2. The grease according to claim 1, characterized by comprising 30% to 80% by weight of an ester composition, 5% to 20% by weight of calcium carbonate, and 5% to 25% by weight of an overbasic mono-, di-, or tri-alkylbenzene sulfonate.
3. The grease according to claim 1 or 2, characterized by comprising 50% to 65% by weight of an ester composition, 10% to 15% by weight of calcium carbonate, and 12% to 20% by weight of an overbasic mono-, di-, or tri-alkylbenzene sulfonate.