Hybrid grease prepared using anhydrous metal soap and overbasic metal cleaning agent, and method for preparing it.

Abstract

A grease suitable for high-temperature applications and a cost-effective alternative to lithium grease. The grease can be prepared from an oil of lubricating viscosity; 1.0–22.5% by weight of an overbasic metal cleaner; 5.0–18.5% by weight of a metal carboxylate soap component, which is a reaction product of metal hydroxides and / or metal carbonates with fatty acids; 0.2–8.0% by weight of an oxygenation accelerator (e.g., alcohol and / or organic acid); and 1–15% by weight of water. The grease has a dropping point of at least 220°C, as measured using ASTM D2265.

Description

[Technical Field]

[0001] The technical field of this disclosure generally relates to greases prepared from a mixture of a metal carboxylate soap and an overbasic metal cleaning agent, and to methods for preparing the same. [Background technology]

[0002] To ensure lubrication performance in high-temperature applications, it is crucial to consider the heat resistance of the grease. One way to obtain an indicator of the heat resistance of a grease is to measure its dropping point. The dropping point, as defined by ASTM D2265, is a numerical value assigned to a grease composition and represents the corrected temperature at which the first drop of material falls from the test cup and reaches the bottom of the test tube. At temperatures above 200°C, the dropping point test is applied as a quality control tool to ensure that the thickening agent system has been properly prepared. Hydrated calcium soap, or cup grease, offers the lowest cost position among all grease thickeners. However, due to their low dropping points, they are typically limited to applications with maximum temperatures of around 80°C. Anhydrous calcium soap, manufactured from slaked lime and 12-hydroxystearic acid, typically has a dropping point in the range of 150-160°C, is also relatively inexpensive, and is easy to use as a grease thickener.

[0003] However, most specifications for multipurpose greases require a dropping point above 175°C. Conventional (anhydrous) lithium 12-hydroxystearate soap is commonly used for multipurpose applications because its dropping point is approximately 200°C. The dropping points of lithium 12-hydroxystearate and calcium 12-hydroxystearate soap or anhydrous grease types can be increased by adding borate-containing additives such as borate esters. Conventional lithium 12-hydroxystearate grease treated with complexing agents such as boron-containing additives has a dropping point of approximately 260°C, while anhydrous calcium grease typically has a dropping point of only about 180°C.

[0004] Over the past few years, overbasic metal cleaning greases, typically based on overbasic sulfonate calcium, have become more common in industrial applications. These greases can function up to approximately 160°C and have a dropping point above 300°C. These greases typically come with a significant cost premium, 50% more than commercially available lithium grease and 30% more than lithium grease thermally stabilized with boron-containing additives.

[0005] However, the increasing demand for lithium batteries in the electronics and electric vehicle markets has driven up the price of lithium hydroxide significantly, pushing the cost of lithium grease to an unacceptable level in the global grease market. Therefore, there is a need for more cost-effective alternatives to general-purpose lithium grease. [Overview of the Initiative]

[0006] Therefore, the disclosed technology provides a more cost-effective alternative to lithium grease with improved temperature stability in high-temperature applications. These greases are prepared using a combination of metal carboxylate soap and an overbasic metal cleaning agent, and have a higher dropping point than greases prepared with anhydrous calcium soap, and perform comparably to lithium 12-hydroxystearate soap thickened grease.

[0007] Accordingly, a grease prepared from an oil of lubricating viscosity; 1.0 to 22.5% by weight of an overbasic metal cleaner solubilized in a liquid diluent; 5 to 18.5% by weight (or 9.0 to 18.5% by weight) of a metal carboxylate soap component which is a reaction product of a metal hydroxide and / or metal carbonate with a fatty acid; 0.2 to 8.0% by weight (or 0.2 to 5% by weight) of an oxygenation accelerator (e.g., alcohol and / or organic acid); and 1 to 15% by weight of water is disclosed.

[0008] In some embodiments, the overbasic metal cleaner may be present in a range of 5–15% by weight or 10–15% by weight, based on the total yield of the grease. The overbasic metal cleaner may have a total base number (TBN) of 150–500 (or 200–500, 300–400, or 400) mg KOH / g equivalent. In some embodiments, the solubilized overbasic metal cleaner contains 75% by weight or less (or 70, 60, or 55% by weight or less) of a liquid diluent. Suitable overbasic metal cleaners include overbasic metal sulfonates, salicylates, naphthenates, phenates, or oleates, or mixtures thereof. These overbasic metal cleaners may be prepared from at least one overbasic alkali or alkaline earth metal salt, such as sodium salt, calcium salt, magnesium salt, barium salt, lithium salt, potassium salt, or mixtures thereof. In some embodiments, the overbasic metal cleaning agent is an overbasic calcium sulfonate cleaning agent having an optional 400 mg KOH / g equivalent of TBN.

[0009] The metal carboxylate soap may also be a reaction product of 0.5 to 2.1% (or 1.5% by weight) of a metal hydroxide and 5 to 16% (or 11.3% by weight) of a fatty acid, wherein the metal hydroxide comprises at least one alkali or alkaline earth metal hydroxide (e.g., sodium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, lithium hydroxide, potassium hydroxide, or a mixture thereof). In some embodiments, the metal hydroxide is calcium hydroxide. The fatty acid may comprise at least one of oleic acid, stearic acid (e.g., 12-hydroxystearic acid), ricinoleic acid, or a combination thereof.

[0010] The oxygenation accelerator used to prepare the grease may be an organic acid and / or an alcohol. Suitable organic acids include, but are not limited to, acetic acid, succinic acid, phosphoric acid, sulfamic acid, 2-acrylamido-2-methylpropanesulfonic acid, alkylated benzenesulfonic acid, or a combination thereof. Suitable alcohols include, but are not limited to, methanol, isopropanol, 2-methoxyethanol, propylene glycol (which may be a mixture of 1,2- and 1,3-propanediol), dipropylene glycol, butanol, amyl alcohol, 2-ethyl-1,3-hexanediol, 2-methyl-2-4-pentanediol, 2-methoxyethanol, diethylene glycol monobutyl ether, 1,2-hexanediol, 1,2-butanediol, 2,3-butanediol, 1,3-butanediol, 2,5-dimethyl-2,5-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, triethylene glycol methyl ether, 3-methyl-1,3-butanediol, 1,2-pentanediol, 2-butoxyethanol, or combinations thereof.

[0011] The lubricating viscosity oil comprises at least one paraffinic oil, naphthenic oil, polyalphaolefin, liquid ethylene oxide / propylene oxide copolymer, polyalkylene glycol, seed oil, vegetable oil, ester, or a mixture thereof. In some embodiments, the lubricating viscosity oil may comprise at least one API group I, II, III, IV, or V oil, or ATIEL group VI, or a mixture thereof. In yet other embodiments, the lubricating viscosity oil may be an API group II oil.

[0012] In some embodiments, the grease may contain at least one additive to improve one or more of the grease's performance characteristics. Additives include, but are not limited to, wear inhibitors, friction modifiers, extreme pressure agents, corrosion inhibitors, antioxidants, viscosity modifiers, tackifiers, or mixtures thereof.

[0013] The resulting grease may be a hybrid grease containing both an anhydrous metal soap and a hyperbasic metal cleaner. A method for producing a hybrid grease is also disclosed. This method may comprise two steps, steps (I) and (II), for producing a hybrid grease. Step (I) may comprise the step of mixing (i) an oil of lubricating viscosity; (ii) 0.5 to 2.1% by weight (or 1.5% by weight) of a metal hydroxide and / or metal carbonate; and (iii) 5 to 16% by weight (or 11.3% by weight) of a fatty acid and (iv) 1 to 15% by weight of water to form an anhydrous grease. The mixture in step (I) may be mixed and heated at 70 to 90°C for 1 to 2 hours until it is saponified to form an anhydrous grease.

[0014] For step (II), the anhydrous grease obtained may then be mixed with (i) 1 to 22.5% (or 12% by weight) of an overbasic metal cleaner solubilized in a liquid diluent, (ii) 0.2 to 5.0% by weight of an oxygenation accelerator (e.g., alcohol and / or organic acid), and (iii) 1 to 15% by weight of water to form a hybrid grease. The mixture from step (II) can be mixed at 70 to 95°C for 1 to 2 hours. The hybrid grease obtained from step (II) can be heated to 850 to 900, or 870 to 890 cm⁻¹. -1 It may have FTIR peaks in the range of [specify range]. The dropping point of the hybrid grease may be 220°C, 250°C, or above 300°C, measured using a dropping point test (e.g., ASTM D2265, ISO 2176, or IP 396). [Modes for carrying out the invention]

[0015] Novel greases prepared using a combination of metal carboxylate soap and an overbasic metal cleaning agent are disclosed herein. These greases have a higher dropping point than greases prepared with anhydrous metal soap. Various preferred features and embodiments are described below as non-limiting examples.

[0016] The grease may be prepared from an oil of lubricating viscosity; 1.0 to 22.5% by weight of an overbasic metal cleaner; 5.0 to 18.5% by weight (or 9.0 to 18.5% by weight) of a metal carboxylate soap component, which is a reaction product of metal hydroxides and / or metal carbonates with fatty acids; 0.2 to 8.0% by weight (or 0.2 to 5% by weight, or 0.5 to 5.0% by weight) of an oxygenation accelerator (e.g., alcohols and / or organic acids); and 1 to 15% by weight of water.

[0017] Over-basic metal cleaning agent The grease may be prepared using any overbasic metal cleaner known in the art. Overbasic metal cleaners, also called metal-containing overbasic cleaners or superbasic salts, are characterized by a metal content exceeding the amount of metal and certain acidic organic compounds that react with the metal, i.e., the amount of metal that would be necessary for neutralization according to the stoichiometry of the substrate. Overbasic cleaners may contain one or more of the following: non-sulfur-containing phenates, sulfur-containing phenates, sulfonates, salicylates, and mixtures thereof. Alternatively, an overbasic metal cleaner may contain at least one overbasic metal sulfonate, salicylate, naphthenate, or oleate cleaner, or a mixture thereof.

[0018] The amount of excess metal is generally expressed as the substrate-to-metal ratio. The term "metallic ratio" is used in the prior art and herein to define the ratio of the total chemical equivalents of metal in an overbasic salt to the chemical equivalents of metal in the salt expected to result from a reaction between a hydrocarbyl-substituted organic acid, i.e., a hydrocarbyl-substituted phenol or mixture thereof that is overbasicated, and a basic metal compound, according to the known chemical reactivity and stoichiometry of the two reactants. The hydrocarbyl-substituted phenol or mixture thereof is overbasicated, and the basic metal compound follows the known chemical reactivity and stoichiometry of the two reactants. Thus, in ordinary salts or neutral salts (i.e., soap), the metallic ratio is 1, and in overbasic salts, the metallic ratio is greater than 1, particularly greater than 1.3. Overbasic detergents may have a metallic ratio of 5 to 30, or a metallic ratio of 7 to 22, or at least a metallic ratio of 11.

[0019] Metal-containing detergents may also include "hybrid" detergents formed from a mixed surfactant system containing phenate and / or sulfonate components, such as phenate salicylate, sulfonate phenate, sulfonate salicylate, and sulfonate phenate salicylate. For example, when using a hybrid sulfonate / phenate detergent, the amount of this hybrid detergent is considered equivalent to the amounts of separate phenate and sulfonate detergents introducing similar amounts of phenate soap and sulfonate soap, respectively.

[0020] Overbasic detergents can be characterized by their total base number (TBN), which is the amount of strong acid required to neutralize all basicity of a material, expressed as mg KOH per gram of sample. TBN is a very well-known parameter described in ASTM D4739. Since the overbasic detergents used herein are generally provided in forms containing liquid diluents, for the purposes of this specification, the TBN should be recalculated against an oil-free standard. Various detergents may have a TBN of 100–1000, or 150–800, or 400–700. Detergents may have a TBN of at least 640, for example, 650–1000, or even 680–800. In each case, the unit is mg KOH / g equivalent. Overbasic phenates and salicylates typically have a total base number of 180–450. Overbasic sulfonates typically have a total base number of 250–600, or 300–500.

[0021] Alkylphenols are often used as components in and / or as building blocks of overbasic detergents. Alkylphenols can be used to prepare phenates, salicylates, salixalates, or saligenin detergents or mixtures thereof. Suitable alkylphenols include para-substituted hydrocarbylphenols. The hydrocarbyl group can be a linear or branched aliphatic group with 1 to 60 carbon atoms, 8 to 40 carbon atoms, 10 to 24 carbon atoms, 12 to 20 carbon atoms, or 16 to 24 carbon atoms.

[0022] The overbased metal-containing detergent can be an alkali metal salt or an alkaline earth metal salt. In one embodiment, the overbased detergent is a sodium, calcium, magnesium, barium, lithium salt of phenate or a mixture thereof, a sulfur-containing phenate, a sulfonate, a salicylate, a salicylate, a naphthalene, a naphthenate or an oleate, or a mixture thereof. In one embodiment, the overbased detergent is a calcium detergent, a magnesium detergent or a mixture thereof. In one embodiment, the overbased detergent does not contain or substantially contains sodium.

[0023] Salicylate detergents and overbased salicylate detergents can be prepared in at least two different ways. In the first method, the detergent can be prepared by carbonylation (also called carboxylation) of p-alkylphenol, followed by overbasing to form an overbased salicylate detergent. Suitable p-alkylphenols include those having a linear and / or branched hydrocarbyl group of 1 to 60 carbon atoms. Salicylate detergents can also be prepared by alkylation of salicylic acid followed by overbasing. The salicylate detergents thus prepared can be prepared from linear and / or branched alkylating agents (usually 1-olefins) containing 6 to 50 carbon atoms, 10 to 30 carbon atoms, or 14 to 24 carbon atoms.

[0024] In one embodiment, the overbased metal-containing detergent can be a predominantly linear alkylbenzene sulfonate detergent having a metal ratio of at least 8. The linear alkyl group may be bonded to the benzene ring at any position along the straight chain of the alkyl group, but in many cases it is bonded at the 2nd, 3rd or 4th position of the straight chain, and in some cases mainly at the 2nd position, resulting in a linear alkylbenzene sulfonate detergent.

[0025] Thus, in some embodiments, the overbased metal detergent can have a total base number (TBN) of 150 to 500 (or 200 to 500, 300 to 400, or 400) mg KOH / g equivalent. Suitable overbased metal detergents include overbased metal sulfonates, salicylates, naphthenates, phenates or oleates detergents, or mixtures thereof. These overbased metal detergents can be prepared from at least one overbased alkali or alkaline earth metal salt, such as sodium salt, calcium salt, magnesium salt, barium salt, lithium salt, potassium salt or mixtures thereof. In some embodiments, the overbased metal detergent is an overbased calcium sulfonate detergent optionally having a TBN of 400 mg KOH / g equivalent. In some embodiments, the overbased metal detergent can be present in an amount ranging from 1 to 22.5 wt%, or 5 to 15 wt%, or 12 wt% based on the total amount of the grease.

[0026] The solubilized overbased metal detergent can be solubilized in a liquid diluent. The liquid diluent is not overly limited and includes those known in the art. The liquid diluent can be selected based on the type of substrate, the overbasing process, or the intended end use of the overbased detergent. Suitable liquid diluents include mineral oils (including food grade white oils) and polyalphaolefins. For the greases disclosed herein, the solubilized overbased metal detergent contains 75 wt% or less (or 70, or 60, or 55 wt% or less) of the liquid diluent. In some embodiments, the solubilized overbased metal detergent contains 30 to 40 wt% of a liquid diluent that is a mineral oil. The diluent oil can have an ISO viscosity grade (VG) of 22 to 32. Lubricating viscosity oils having a kinematic viscosity in the range of ISO VG 46 to ISO VG 150 can also be used as the diluent oil.

[0027] Metal carboxylate soap The metal carboxylate soap may be a reaction product of a metal hydroxide and a fatty acid, the metal hydroxide comprising at least one alkali or alkaline earth metal hydroxide (e.g., sodium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, lithium hydroxide, potassium hydroxide, or a mixture thereof). In some embodiments, the metal hydroxide is calcium hydroxide. The fatty acid may comprise at least one of oleic acid, stearic acid (e.g., 12-hydroxystearic acid), ricinoleic acid, or a combination thereof. The metal carboxylate soap may be present in an amount of 5.0–18.5% by weight, or 9–18.5% by weight, or 12–13% by weight, based on the total yield of the grease.

[0028] Oxygen accelerator Oxygen accelerators may be used to shorten conversion time and promote grease formation. Suitable oxygen accelerators are not overly limited and include any accelerator known in the art, e.g., water, alcohol, acid, or mixtures thereof. Therefore, in some embodiments, the oxygen accelerator used to prepare the grease may be an organic acid and / or alcohol. Suitable organic acids include, but are not limited to, acetic acid, succinic acid, phosphoric acid, sulfamic acid, 2-acrylamido-2-methylpropanesulfonic acid, alkylated benzenesulfonic acid, or combinations thereof. In one embodiment, the alkylated benzenesulfonic acid is C9-C 12 , or C 10 ~C 13 Or C9~C 16Alkylated benzenesulfonic acid may also be used. Suitable alcohols include, but are not limited to, methanol, isopropanol, 2-methoxyethanol, propylene glycol (may be a mixture of 1,2- and 1,3-propanediol), dipropylene glycol, butanol, amyl alcohol, 2-ethyl-1,3-hexanediol, 2-methyl-2-4-pentanediol, 2-methoxyethanol, diethylene glycol monobutyl ether, 1,2-hexanediol, 1,2-butanediol, 2,3-butanediol, 1,3-butanediol, 2,5-dimethyl-2,5-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, triethylene glycol methyl ether, 3-methyl-1,3-butanediol, 1,2-pentanediol, 2-butoxyethanol, or combinations thereof. The oxygenation accelerator may be present in an amount of 0.2–5% by weight, or 0.2–5% by weight, or 0.5–2.5% by weight, based on the total yield of the grease.

[0029] Lubricating viscosity of oil One of the components of a grease composition is an oil of lubricating viscosity. These include natural and synthetic oils of lubricating viscosity, oils derived from hydrocracking, hydrotizing, or hydrofinishing, as well as unrefined oils, refined oils, and re-refined oils, and mixtures thereof.

[0030] Examples of natural oils include animal oils, vegetable oils, mineral oils, and mixtures thereof. Examples of synthetic oils include hydrocarbon oils, silicon-based oils, and liquid esters of phosphorus-containing acids. Synthetic oils can be produced by the Fischer-Tropsch gas-liquid synthesis procedure and other gas-liquid oils. In one embodiment, the compositions of the present invention are useful when used in gas-liquid oils. Often, Fischer-Tropsch hydrocarbons or waxes can be hydrogen-isomerized. In one embodiment, the base oil comprises a polyalphaolefin containing PAO-2, PAO-4, PAO-5, PAO-6, PAO-7, or PAO-8. The polyalphaolefin in one embodiment may be prepared from octene, decene, dodecene, or mixtures thereof. A further suitable polyalphaolefin is metallocene polyalphaolefin. In one embodiment, the oil of lubricating viscosity comprises an ester such as an adipate.

[0031] Lubricating viscosity of oil can also be defined as specified in the American Petroleum Institute (API) Base Oil Interchangeability Guidelines.

[0032] Base oil category, Sulfur (%), Saturation (%), Viscosity index Group I > 0.03 and / or < 90 (80 to less than 120) Group II ≤ 0.03 and ≥ 90 (80 to less than 120) Group III ≤ 0.03 and ≥ 90 > 120 Group IV: All polyalphaolefins (PAOs) All others not included in Group V, Group I, II, III, or IV

[0033] Groups I, II, and III are mineral oil-based stocks. Other commonly recognized categories of base oils may be used, even if not officially specified by the API. Group II+ refers to Group II materials having a viscosity index of 110–119 and lower volatility than other Group II oils, and Group III+ refers to Group III materials having a viscosity index of 130 or higher. Lubricating viscosity oils may include natural or synthetic oils and mixtures thereof. Mineral oils and synthetic oils, such as mixtures of polyalphaolefin oils and / or polyester oils, may be used.

[0034] Lubricating viscosity oils can also be defined as specified in the Technical Association of the European Lubricants Industry (ATIEL) Base Oil Interchangeability Guidelines. The ATIEL guidelines include the polyinternal olefin base oil category, ATIEL Group VI.

[0035] Therefore, in some embodiments, the lubricating viscosity oil may comprise at least one paraffinic oil, naphthenic oil, liquid ethylene oxide / propylene oxide copolymer, polyalphaolefin, polyalkylene glycol, seed oil, vegetable oil, ester, or a mixture thereof. In some embodiments, the lubricating viscosity oil may comprise at least one API group I, II, III, IV, or V oil, or ATIEL group VI, or a mixture thereof. In another embodiment, the lubricating viscosity oil is a group II base oil, which may comprise polybutene and / or polyisobutylene to increase viscosity and improve tackiness and water treatment properties.

[0036] The amount of lubricating viscosity oil present is typically the remainder after subtracting from about 100% by weight the total amount of other components used to manufacture the grease disclosed herein, including any of the performance additives described below. Generally, the lubricating viscosity oil may be present at least 50% by weight based on the total weight of the grease composition. In some embodiments, the grease is present at 50–90% by weight, or 60–80% by weight, or 65–75% by weight based on the total weight of the grease composition.

[0037] Additional performance additives In some embodiments, the grease may contain at least one additive to improve one or more of the grease's performance characteristics. Additives include, but are not limited to, wear inhibitors, friction modifiers, extreme pressure agents, corrosion inhibitors, antioxidants, viscosity modifiers, tackifiers, or mixtures thereof. These additives may help improve the wear or friction properties of the grease. Some additives, such as antioxidants, may help improve the stability of the grease and / or reduce its reactivity to other materials in the environment. The grease may also contain corrosion inhibitors to help inhibit corrosion of the metal in contact with the grease.

[0038] Typically, the anti-wear agent may be a phosphorus-based anti-wear agent. The anti-wear agent may be present in 0% to 5% by weight, 0.001% to 2% by weight, or 0.1% to 2.0% by weight of the grease. The phosphorus-based anti-wear agent may contain phosphate amine salts, calcium salts, or mixtures thereof. Phosphate amine salts include amine salts of phosphate esters or mixtures thereof. Examples of amine salts of phosphate esters include phosphate esters and their amine salts; dialkyldithiophosphate esters and their amine salts, phosphites; and amine salts of phosphorus-containing carboxylic acid esters, ethers, and amides; hydroxy-substituted di or triesters of phosphoric acid or thiophosphate and their amine salts; phosphorylated hydroxy-substituted di or triesters of phosphoric acid or thiophosphate and their amine salts; and mixtures thereof. In one embodiment, the oil-soluble phosphate amine salt includes a partially amine salt-partial metal salt compound or mixtures thereof. In one embodiment, the phosphorus compound further contains a sulfur atom in the molecule. In another embodiment, the phosphorus compound is a derivative of calcium.

[0039] Examples of wear-resistant agents may include nonionic phosphorus compounds (typically compounds having phosphorus atoms in an oxidation state of +3 or +5). In one embodiment, the amine salt of the phosphorus compound may be ash-free, i.e., metal-free (before mixing with other components).

[0040] In one embodiment, the anti-wear additive may include zinc dialkyldithiophosphate. In other embodiments, the grease may be substantially or completely free of zinc dialkyldithiophosphate. In yet another embodiment, the grease may contain a dithiocarbamate anti-wear agent as defined in column 2, line 35 to column 6, line 11 of U.S. Patent No. 4,758,362. Where present, the dithiocarbamate anti-wear agent may be present in the total composition in amounts of 0.25% by weight, 0.3% by weight, 0.4% by weight, or further 0.5% by weight to a maximum of 3.0% by weight, 2.5% by weight, 2.0% by weight, or further 0.55% by weight.

[0041] In some embodiments, the grease may contain one or more extreme pressure agents. Suitable extreme pressure agents include organic sulfides. In one embodiment, the organic sulfide comprises at least one of polysulfides, thiadiazole compounds, or mixtures thereof. The extreme pressure agent may be present in the grease in amounts ranging from 0% to 10% by weight, 0.01% to 10% by weight, 0.1% to 8% by weight, 0.25% to 6% by weight, 2% to 5% by weight, or 3% to 5% by weight.

[0042] Examples of thiadiazoles include 2,5-dimercapto-1,3,4-thiadiazole or its oligomers, hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole, and hydrocarbylthio-substituted 2,5-dimercapto-1,3,4-thiadiazole or its oligomers. Oligomers of hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole are usually formed by forming sulfur-sulfur bonds between 2,5-dimercapto-1,3,4-thiadiazole units to form two or more oligomers of the thiadiazole unit. Further examples of thiadiazole compounds can be found in International Publication No. 2008 / 094759, paragraphs 0088-0090.

[0043] Alternatively, the organic sulfide may be a polysulfide. In one embodiment, at least about 50% by weight of the polysulfide molecule is a mixture of trisulfides or tetrasulfides. In other embodiments, at least about 55% by weight, or at least about 60% by weight, of the polysulfide molecule is a mixture of trisulfides or tetrasulfides. The polysulfide includes sulfurized organic polysulfides from oils, fatty acids, or esters, olefins, or polyolefins.

[0044] Oils that can be sulfurized include natural or synthetic oils, such as mineral oil, lard, aliphatic alcohols and carboxylic acid esters derived from fatty acids or aliphatic carboxylic acids (e.g., myristyl oleate and oleyl oleate), as well as synthetic unsaturated esters or glycerides.

[0045] Fatty acids include those containing 8 to 30 or 12 to 24 carbon atoms. Examples of fatty acids include oleic acid, linoleic acid, linolenic acid, and tall oil. Sulfurized fatty acid esters prepared from mixed unsaturated fatty acid esters can be obtained from animal fats and vegetable oils, such as tall oil, flaxseed oil, soybean oil, rapeseed oil, and fish oil.

[0046] Polysulfides can also be derived from olefins derived from a wide range of alkenes, typically having one or more double bonds. In one embodiment, the olefin contains 3 to 30 carbon atoms. In other embodiments, the olefin contains 3 to 16 or 3 to 9 carbon atoms. In one embodiment, the sulfurized olefin includes olefins derived from propylene, isobutylene, pentene, or mixtures thereof. In one embodiment, the polysulfide includes polyolefins derived from polymerization by known techniques, the olefins mentioned above. In one embodiment, the polysulfide includes dibutyltetrasulfide, methyl sulfide esters of oleic acid, alkylphenol sulfide, dipentene sulfide, dicyclopentadiene sulfide, terpene sulfide, and Diels-Alder sulfide adducts; phosphorosulfide hydrocarbons.

[0047] Examples of friction modifiers include aliphatic amines, glycerol borate esters, fatty acid amides, non-borodic aliphatic epoxides, aliphatic borate epoxides, alkoxylated aliphatic amines, alkoxylated aliphatic amines, metal salts of fatty acids, aliphatic imidazolines, metal salts of alkyl salicylates (which may also be referred to as detergents), metal salts of sulfonates (which may also be referred to as detergents), condensation products of carboxylic acids or polyalkylene-polyamines, or amides of hydroxyalkyl compounds. In one embodiment, the friction modifier includes a fatty acid ester of glycerol. The fatty acid may contain 6 to 24 or 8 to 18 carbon atoms. In one embodiment, the friction modifier may include a product of isostearic acid and tetraethylenepentamine. A more detailed list of possible friction modifiers can be found in paragraphs 0100-0113 of International Publication No. 2008 / 094759. The friction modifier may be present in amounts of 0% to 7% by weight, 0.1% to 6% by weight, 0.25% to 5% by weight, or 0.5% to 5% by weight of the grease.

[0048] In some embodiments, the grease may contain at least one metal deactivator (often called a corrosion inhibitor). This metal deactivator may contain one or more derivatives of benzotriazole, benzimidazole, 2-alkyldithiobenzimidazole, 2-alkyldithiobenzothiazole, 2-(N,N-dialkyldithiocarbamoyl)benzothiazole, 2,5-bis(alkyldithio)-1,3,4-thiadiazole, 2,5-bis(N,N-dialkyldithiocarbamoyl)-1,3,4-thiadiazole, 2-alkyldithio-5-mercaptothiadiazole, or mixtures thereof.

[0049] The benzotriazole compound may contain hydrocarbyl substitution at one or more ring positions of the following 1-, 2-, 4-, 5-, 6-, or 7-benzotriazoles. The hydrocarbyl group may contain 1 to 30 carbon atoms, 1 to 15 carbon atoms in one embodiment, and 1 to 7 carbon atoms in another embodiment. The metal deactivator may include 5-methylbenzotriazole. The metal deactivator may be present in the grease composition at concentrations up to 5% by weight, or in the range of 0.0002 to 2% by weight, or 0.001 to 1% by weight.

[0050] In some embodiments, the grease may contain at least one rust inhibitor (often called a corrosion inhibitor). The rust inhibitor may include one or more metal sulfonates, such as calcium sulfonate, magnesium sulfonate, or barium sulfonate; amine salts of carboxylic acids, such as octylamine octanoate; condensation products of dodecenyl succinic acid or anhydrides and fatty acids, such as oleic acid, and polyamines, such as polyalkylene polyamines, such as triethylenetetramine; or semi-esters of alkenyl succinic acid containing 8 to 24 carbon atoms in an alkenyl group and alcohols, such as polyglycols.

[0051] The rust inhibitor may be present in the grease composition at concentrations ranging from up to 4% by weight, in one embodiment from 0.02% to 2% by weight, and in another embodiment from 0.05% to 1% by weight.

[0052] In one embodiment, the grease composition contains an antioxidant or a mixture thereof. The antioxidant may be present in an amount of 0% to 15% by weight, or 0.1% to 10% by weight, or 0.5% to 5% by weight, or 0.5% to 3% by weight, or 0.3% to 1.5% by weight of the grease composition. Examples of antioxidants include diarylamine alkylated diarylamines, hindered phenols, dithiocarbamates, 1,2-dihydro-2,2,4-trimethylquinoline, hydroxylthioethers, or mixtures thereof.

[0053] Diarylamine alkylated diarylamines may be phenyl-α-naphthylamine (PANA), alkylated diphenylamine, or alkylated phenylnaphthylamine, or mixtures thereof. Examples of alkylated diphenylamines include dinonyl diphenylamine, nonyl diphenylamine such as Lubrizol® GR9510, octyl diphenylamine, dioctyl diphenylamine, or didecyl diphenylamine. Examples of alkylated diarylamines include octyl, dioctyl, nonyl, dinonyl, decyl, or didecylphenylnaphthylamine. In one embodiment, the alkylated diphenylamine may include at least one of octyl diphenylamine, butylated diphenylamine, or mixtures thereof, for example, Irganox® L57 manufactured by BASF.

[0054] Hindered phenol antioxidants often contain secondary and / or tertiary butyl groups as sterically hindering groups. The phenol group may be further substituted with a hydrocarbyl group (typically a linear or branched alkyl group) and / or a crosslinking group bonded to a second aromatic group. The crosslinking atom may be carbon or sulfur. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol, or 4-butyl-2,6-di-tert-butylphenol, or 4-dodecyl-2,6-di-tert-butylphenol. In one embodiment, the hindered phenol antioxidant may be an ester, for example, Irganox® L135 manufactured by BASF. A more detailed description of the chemistry of suitable ester-containing hindered phenol antioxidants can be found in U.S. Patent No. 6,559,105.

[0055] The dithiocarbamate antioxidant may contain metals such as molybdenum or zinc dithiocarbamate, or it may be "ashless." Ashless refers to a dithiocarbamate that does not contain metals, and the linking group is typically a methylene group. 1,2-dihydro-2,2,4-trimethylquinoline may exist as a distinct molecule or be oligomerized into up to five repeating units, and is commercially known as "resin D" or simply "RD" and is available from many suppliers.

[0056] Suitable viscosity modifiers include polyolefins, olefin copolymers, ethylene / propylene copolymers, polyisobutene, styrene-isoprene polymers, styrene / maleate copolymers, styrene-butadiene copolymers, styrene-isoprene polymers, α-olefin maleic anhydride copolymers, polymethacrylates, polyacrylates, polyalkylstyrenes, hydrated alkenylaryl conjugated diene copolymers, and mixtures thereof. Viscosity modifiers may include, for example, star polymers as described in U.S. Patent Application Publication No. 2012 / 0101017 A1.

[0057] The grease composition may additionally or alternatively contain one or more dispersing viscosity modifiers. Suitable dispersing viscosity modifiers include functionalized polyolefins, e.g., ethylene-propylene copolymers functionalized with reaction products of acylating agents (such as maleic anhydride) and amines; amine-functionalized polymethacrylates; esterified maleic anhydride-styrene copolymers reacted with amines; and mixtures thereof.

[0058] If present, one or more viscosity modifiers may total at least 0.01% by weight, or at least 0.1% by weight, or at least 0.5% by weight, or up to 10% by weight, or up to 5% by weight, or up to 3% by weight of the grease composition.

[0059] The tackifier may be polybutene and / or polyisobutylene having a number average molecular weight of 2000 to 4000. Examples of commercially available tackifiers and their chemical types include polyisobutylene (such as Indopol® from Ineos or Parapol® from ExxonMobil); olefin copolymers (e.g., Lubrizol®, 7065c, and 7067c from Lubrizol, and Lucant® HC-2000, HC-1000, and HC-600 from Mitsui); styrene-isoprene copolymers (e.g., Shellvis® 40 and 50 from Infineum or Functional Products, and Lubrizol® 7306 and 7308 from Lubrizol); and styrene / butadiene copolymers, such as Lubrizol® 7408A from Lubrizol. A concentration of 0.2 to 3% by weight relative to the total weight of the grease composition can also be used.

[0060] A method for preparing grease is also disclosed. The grease preparation method may be carried out in an open or closed kettle, as is commonly used in grease production, or in a pressurized reactor. This method can be achieved at normal atmospheric pressure, but can also be carried out under pressure in a closed pressurized reactor or autoclave. In one embodiment, the method is carried out in an open kettle. Post-treatment of the grease may include one or more steps of grinding, filtering, adding performance additives, and packaging the grease, and is carried out in a manner known to a person familiar with grease production.

[0061] The method may include producing a hybrid grease in two steps, steps (I) and (II). Step (I) may include mixing (i) an oil of lubricating viscosity; (ii) 0.5 (or 1-2.1% by weight, or 1.5% by weight) of metal hydroxide and / or metal carbonate; (iii) 5-16% by weight (or 8-16% by weight, or 11.3% by weight) of fatty acids; and (iv) 1-15% by weight (or 2-5% by weight) of water to form an anhydrous grease. The mixture in step (I) may be mixed and heated at 70-90°C for 1-2 hours until it is saponified to form an anhydrous grease. The conversion of the mixture to an anhydrous grease can be determined using Fourier transform infrared spectroscopy ("FTIR"). If converted, the grease has a viscosity of 1540-1600 cm². -1 It should have at least one FTIR spectral peak between these points.

[0062] For step (II), the anhydrous calcium grease obtained may then be mixed with (i) 1-22.5% (or 12% by weight) of an overbasic metal cleaner, (ii) 0.2-8.0% (or 0.5-5% by weight) of an oxygenation accelerator (e.g., alcohol and / or organic acid), and (iii) 1-15% (or 2-5% by weight) of water to form a hybrid grease. The mixture from step (II) can be mixed at 70-95°C for 1-2 hours. The hybrid grease obtained from step (II) can be heated to 850-900°C or 870-890 cm². -1 It may have FTIR peaks in the range of [specify range]. The dropping point of the hybrid grease may be 220°C, 250°C, or above 300°C, measured using a dropping point test (e.g., ASTM D2265, ISO 2176, or IP 396).

[0063] The water used in both steps (I) and (II) helps to promote the reaction of the various components. If excess water is used, it can be evaporated in step (II) or as part of the finishing process. In some embodiments, the amount of water used in both steps (I) and (II) is in the range of 2–5% by weight, and any excess water is evaporated in step (II) or as part of the finishing process.

[0064] In one embodiment, the grease may be prepared from 54-90% by weight of a base oil (e.g., a base oil of group II), 1-2.1% by weight of a metal hydroxide (e.g., calcium hydroxide), 8-16% by weight of a fatty acid (e.g., 12-hydroxystearic acid), 1-15% by weight of water, 1-22.5% by weight of an overbasic metal cleaner (e.g., an overbasic calcium sulfonate cleaner), 0.2-2.5% by weight of an oxygenation accelerator which is an alcohol (e.g., 2-ethyl-1,3-hexanediol), and 0.5-2.5% by weight of an acid (e.g., alkylated benzenesulfonic acid). In another embodiment, the grease may be prepared from 72.8% by weight of a base oil (e.g., a Group I base oil), 1.5% by weight of a metal hydroxide (e.g., calcium hydroxide), 11.3% by weight of a fatty acid (e.g., 12-hydroxystearic acid), 8% by weight of water, 12% by weight of an overbasic metal cleaner (e.g., an overbasic calcium sulfonate cleaner), 1.1% by weight of an oxygenation accelerator which is an alcohol (e.g., 2-ethyl-1,3-hexanediol), and 1.3% by weight of an oxygenation accelerator which is an acid (e.g., alkylated benzenesulfonic acid). Further details regarding the manufacture of the grease can be found in the NLGI Lubricating Grease Guide.

[0065] As used herein, the term "hydrocarbyl" refers to a group having carbon atoms directly bonded to the rest of the molecule, the group comprising at least carbon atoms and hydrogen atoms. If the hydrocarbyl group comprises more than one carbon atom, those carbons do not necessarily have to be bonded to one another. For example, at least two carbon atoms may be bonded via a suitable element or group. In various embodiments, the term "hydrocarbyl" refers to a group having carbon atoms directly bonded to the rest of the molecule, the group comprising carbon, hydrogen, and optionally one or more heteroatoms, provided that the heteroatoms do not alter the predominantly hydrocarbon properties of the substituents. Heteroatoms may bond at least two carbon atoms in the hydrocarbyl group and optionally two or fewer non-hydrocarbon substituents. Suitable heteroatoms are obvious to those skilled in the art and include, for example, sulfur, nitrogen, oxygen, phosphorus, and silicon.

[0066] If the hydrocarbyl group contains heteroatoms, optionally there may be two or fewer heteroatoms for every 10 carbon atoms in the hydrocarbyl group. Suitable non-hydrocarbon substituents are also apparent to those skilled in the art and include, for example, halo, hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy substituents.

[0067] Therefore, an example of hydrocarbil in the context of this technology is Hydrocarbon groups selected from aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl, cycloalkadienyl), and aromatic groups; A substituted hydrocarbon group selected from the hydrocarbon groups defined in (i), wherein the substituted hydrocarbon group is substituted with two or fewer non-hydrocarbon substituents and / or one or more hydrocarbon substituents, wherein the non-hydrocarbon substituents are selected from the group consisting of halo, hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy; (i) Examples of hetero-containing hydrocarbon groups selected from hydrocarbon groups defined as containing one or more heteroatoms in a ring or chain (where the group has two or fewer heteroatoms present for every 10 carbon atoms in the group, and the heteroatoms are selected from sulfur, nitrogen, oxygen, phosphorus, and silicon). The hetero-containing hydrocarbon group may be substituted with two or fewer non-hydrocarbon substituents and / or one or more hydrocarbon substituents.

[0068] In some embodiments, the term "hydrocarbyl" refers to a group having carbon atoms directly bonded to the rest of the molecule, and this group consists of carbon and hydrogen atoms.

[0069] The amounts of each chemical component described herein are expressed in terms of active chemical substance, excluding any solvents or diluents that may conventionally be present in commercially available substances, unless otherwise indicated. However, unless otherwise indicated, each chemical substance or composition referred to herein should be construed as a commercially available substance that may contain isomers, by-products, derivatives, and other such substances that are commonly understood to be present in commercial grade.

[0070] Since some of the materials described above can interact in the final formulation, it is known that the components of the final formulation may differ from those initially added. For example, metal ions (e.g., in detergents) can migrate to other acidic or anionic sites of other molecules. The products formed thereby, including those formed when the composition of the present invention is used in its intended application, may not be readily apparent. Nevertheless, all such modifications and reaction products are included within the scope of the present invention. The present invention encompasses compositions prepared by mixing the components described above.

[0071] The grease production methods disclosed herein yield grease compositions having a dropping point of at least 220°C, or at least 250°C, and possibly at least 300°C, thereby making these greases particularly useful in higher temperature applications, which can be better understood by referring to the following examples. [Examples]

[0072] Example A: Preparation of anhydrous calcium grease For Example A, 75% by weight of a Group II base oil, 1.25% by weight of calcium hydroxide, 3% by weight of water, and 8.4% by weight of 12-hydroxystearic acid were added to a reaction vessel and mixed at room temperature for 30 minutes. The temperature was slowly raised to 70°C and maintained for 1 hour with stirring. The temperature was then slowly raised again to approximately 120°C (not exceeding 125°C) and maintained for 1 hour with stirring. The heat to the vessel was then turned off, and the remaining 14.35% by weight of oil was slowly added to the grease in the vessel. The grease was post-treated while still hot.

[0073] Example B: Preparation of conventional (anhydrous) lithium grease In Example B, 43% by weight of Group II base oil and 12.2% by weight of 12-hydroxystearic acid are added to the reaction vessel and mixed while heating to 90°C. A further 43% by weight of Group II base oil is reserved. In a separate container, 1.8% by weight of lithium hydroxide monohydrate and five times its volume of water are heated to near boiling point. When the contents of the first reaction vessel reach 90°C, the lithium hydroxide solution is slowly added to the first reaction vessel. The temperature of the reaction vessel is then slowly increased to 205°C, and some of the reserved base oil is added as needed. When the contents of the reaction vessel reach 205°C, the heat to the vessel is turned off, but mixing continues. When the grease is below 190°C, any of the remaining reserved Group II base oil is slowly added. The grease is post-treated while still hot.

[0074] Example C: Preparation of anhydrous 50 / 50 calcium / lithium mixed grease In Example C, an anhydrous mixed grease is prepared using 50% by weight calcium soap and 50% by weight lithium soap. Approximately 44% by weight of group II base oil and 10.15% by weight of 12-hydroxystearic acid are added to the reaction vessel and mixed while heating to 80°C. A further 44% by weight of group II base oil is reserved. After the acid has dissolved, 0.74% by weight of lithium hydroxide monohydrate, 0.64% by weight of calcium hydroxide, and 2.6% by weight of water are added to the reaction vessel. The temperature of the reaction vessel is then slowly raised to 150°C and maintained at that temperature for 1 hour while mixing. The reserved group II base oil is slowly cooled to 80°C. The grease is post-treated while still hot.

[0075] Example D: Preparation of anhydrous 75 / 25 calcium / lithium mixed grease Example D uses the same process as Example C, except that the anhydrous mixed grease is prepared with 75% by weight of calcium soap and 25% by weight of lithium soap.

[0076] Example E: Preparation of anhydrous 25 / 75 calcium / lithium mixed grease Example E uses the same process as Example C, except that the anhydrous mixed grease is prepared with 25% by weight of calcium soap and 75% by weight of lithium soap.

[0077] Example F (the present invention): Preparation of anhydrous / composite hybrid grease For Example F, 60% by weight (600g) of Group II base oil, 1.25% by weight (12.5g) of calcium hydroxide, 9.4% by weight (94g) of 12-hydroxystearic acid, and 2% by weight (20g) of water were added to a reaction vessel and mixed while heating to 70°C, and held for 1.5 hours. The conversion was confirmed using FTIR. 1540 and 1580 cm -1There should be a peak near. Then, 0.99 wt% (9.9 g) of 2-ethyl-1,3-hexanediol, 12.0 wt% (120 g) of overbased calcium sulfonate (400 TBN), and 3 wt% (30 g) of water are added. Then, 1.3 wt% (13 g) of dodecylbenzene sulfonic acid is slowly added and the temperature is raised to 90 °C. Hold at 90 °C and confirm the grease conversion using FTIR. 875 cm -1 There should be a peak near. When the conversion is complete, slowly raise the temperature of the reaction vessel to 125 °C and slowly add another 15.06 wt% (150.6 g) of Group II base oil. Then, cool the grease to 80 °C. The grease is post-treated while it is hot.

[0078] Example G (the present invention), Preparation of Anhydrous / Complex Hybrid Grease In Example G, an anhydrous mixed grease is prepared using the same process as Example F above, except that 2.5 wt% of a high-performance multi-purpose ("HPM") additive package was added to the grease during post-treatment. The additive package included a combination of an antioxidant which is an alkylated arylamine, a zinc dialkyldithiophosphate anti-wear additive, a zinc neodecanoate rust inhibitor, and a sulfurized olefin extreme pressure additive.

[0079] [[ID=ll]] Example H (the present invention), Preparation of Anhydrous / Complex Hybrid Grease For Example H, 58.24 wt% of Group II base oil, 1.5 wt% of calcium hydroxide, 11.3 wt% of 12-hydroxystearic acid, and 2.96 wt% of water are added to the reaction vessel and mixed at room temperature for 30 minutes. The contents are continuously mixed, heated to 70 °C, and maintained at that temperature for one hour. The conversion is confirmed using FTIR. 1540 and 1580 cm -1A peak should be present in the vicinity. Once the conversion is complete, add 1.1 wt% 2-ethyl-1,3-hexanediol, 12.0 wt% perbasic calcium sulfonate (400 TBN), and 5.84 wt% water, and mix at 70°C for 30 minutes. Then, slowly increase the temperature to 90°C and mix for 1.5 hours. Confirm the conversion again using FTIR. 875 cm⁻¹ -1 A peak should be present in the vicinity. Next, the temperature of the reaction vessel is slowly raised to 120°C and held for 1 hour. Then, the heat to the vessel is turned off, and 14.56% by weight of Group II base oil is slowly added, allowing the grease to cool to 80°C. The grease is post-treated while still hot.

[0080] The dropping point of the grease was measured using ASTM D2265. The results are shown in Table 1 below.

[0081] [Table 1]

[0082] As shown in Table 1, hybrid greases have a higher dropping point than anhydrous lithium grease and provide a more cost-effective alternative to lithium grease, suitable for use in both room temperature and high temperature applications.

[0083] Purpose The greases described herein are found to have applications as high-performance multi-purpose (HPM) greases and high-load capacity (HPM+HL) greases, as defined by NLGI. The greases are also used in applications requiring high temperatures and good load-bearing capacity, such as steel mill applications, heavy industrial machinery, mining, and food manufacturing.

[0084] Each of the documents mentioned above, including any prior application claiming priority, whether or not they are specifically listed above, is incorporated herein by reference. Reference to any document does not constitute an endorsement that such document is eligible as prior art or constitutes the general knowledge of a person skilled in the art in any jurisdiction. Except in the examples or unless otherwise expressly indicated, all quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, etc., should be understood to be modified by the word "about." The upper and lower limits of quantities, ranges, and ratios described herein can be combined independently. Similarly, the ranges and quantities for each element of the present invention can be used together with the ranges or quantities for any of the other elements.

[0085] As used herein, the transitional term “comprising,” which is synonymous with “including,” “contains,” or “characterized by,” is inclusive or open-ended and does not exclude additional undescribed elements or method steps. However, in each “comprising” statement herein, the term is also intended to include, as alternative embodiments, the phrases “essentially from” and “consisting of,” where “consisting of” excludes any unspecified elements or steps, and “essentially from” allows the inclusion of additional undescribed elements or steps that do not substantially affect the basic and novel features of the composition or method under consideration.

[0086] For the purpose of illustrating the present invention, certain representative embodiments and details have been shown, but it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the scope of the invention. In this regard, the scope of the invention should be limited only by the following claims.

Claims

1. It is grease, I. Lubricating viscosity of oil; II. 1.0 to 22.5% by weight of a perbasic metal cleaning agent solubilized in a liquid diluent; III. 5.0 to 18.5% by weight (or 9 to 18.5% by weight) of metal carboxylate soap components, which are reaction products of metal hydroxides and / or metal carbonates with fatty acids; IV. 0.2 to 8.0% by weight (or 0.2 to 5% by weight) of an oxygenation accelerator (e.g., alcohol and / or organic acid); and V. Grease prepared from 1 to 15% by weight of water.

2. The grease according to claim 1 or 2, wherein the solubilized overbasic metal cleaning agent has a total base number (TBN) of 150 to 500 (or 200 to 500, 300 to 400, or 400) mg KOH / g equivalent.

3. The grease according to claim 1 or 2, wherein the solubilized overbasic metal cleaning agent contains 75% by weight or less (or 70%, 60%, or 55% by weight or less) of the liquid diluent.

4. The grease according to any one of claims 1 to 3, wherein the solubilized overbasic metal cleaning agent is present in an amount of 5 to 15% by weight (or 10 to 15% by weight) based on the total yield of the grease.

5. The grease according to any one of claims 1 to 4, wherein the overbasic metal cleaning agent is an overbasic metal sulfonate, salicylate, naphthenate, phenate, or oleate cleaning agent, or a mixture thereof.

6. The grease according to any one of claims 1 to 5, wherein the overbasic metal cleaning agent is prepared from at least one overbasic alkali or alkaline earth metal salt, such as a sodium salt, calcium salt, magnesium salt, barium salt, lithium salt, potassium salt, or a mixture thereof.

7. The grease according to any one of claims 1 to 6, wherein the perbasic metal cleaning agent is optionally a perbasic calcium sulfonate cleaning agent having 400 mg KOH / g equivalent of TBN.

8. The grease according to any one of claims 1 to 7, wherein the metal carboxylate soap is the reaction product of 0.5 to 2.1% by weight (or 1 to 2.1% by weight, or 1.5% by weight) of a metal hydroxide and 5 to 16% by weight (or 8 to 16% by weight, or 11.3% by weight) of a fatty acid, and the metal hydroxide comprises at least one alkali or alkaline earth metal hydroxide (for example, sodium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, lithium hydroxide, potassium hydroxide, or a mixture thereof).

9. The grease according to any one of claims 1 to 8, wherein the metal hydroxide is calcium hydroxide.

10. The grease according to any one of claims 1 to 9, wherein the oxygenation accelerator comprises at least one organic acid, which is acetic acid, succinic acid, phosphoric acid, sulfamic acid, 2-acrylamido-2-methylpropanesulfonic acid, alkylated benzenesulfonic acid, or a combination thereof.

11. The grease according to any one of claims 1 to 10, wherein the oxygenation accelerator comprises at least one alcohol which is methanol, isopropanol, 2-methoxyethanol, propylene glycol, dipropylene glycol, butanol, amyl alcohol, 2-ethyl-1,3-hexanediol, 2-methyl-2-4-pentanediol, 2-methoxyethanol, diethylene glycol monobutyl ether, 1,2-hexanediol, 1,2-butanediol, 2,3-butanediol, 1,3-butanediol, 2,5-dimethyl-2,5-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, triethylene glycol methyl ether, 3-methyl-1,3-butanediol, 1,2-pentanediol, 2-butoxyethanol, or a combination thereof.

12. The grease according to any one of claims 1 to 11, wherein the fatty acid comprises at least one of oleic acid, stearic acid (e.g., 12-hydroxystearic acid), ricinoleic acid, or a combination thereof.

13. The grease according to any one of claims 1 to 12, wherein the oil having a lubricating viscosity comprises at least one paraffinic oil, naphthenic oil, polyalphaolefin, liquid ethylene oxide / propylene oxide copolymer, polyalkylene glycol, seed oil, vegetable oil, ester, or a mixture thereof.

14. The grease according to any one of claims 1 to 13, wherein the oil having a lubricating viscosity comprises at least one API group I, II, III, IV, V oil, or ATIEL group VI oil, or a mixture thereof.

15. The grease according to claim 14, wherein the oil having a lubricating viscosity includes an API Group II oil.

16. The grease according to any one of claims 1 to 15, further comprising at least one additive which is an anti-wear agent, a friction modifier, an extreme pressure agent, a corrosion inhibitor, an antioxidant, a viscosity modifier, a tackifier, or a mixture thereof.

17. The grease according to any one of claims 1 to 16, wherein the grease is a hybrid grease.

18. A method for producing hybrid grease, I. A step of mixing (i) an oil of lubricating viscosity; (ii) 0.5 to 2.1% by weight (or 1.5% by weight) of a metal hydroxide, metal hydroxide and / or metal carbonate; and (iii) 5 to 16% by weight (or 11.3% by weight) of a fatty acid; and (iv) 1 to 15% by weight (or 2 to 8% by weight) of water to form an anhydrous grease; II. A method comprising the steps of: (i) mixing the anhydrous grease with (i) 1 to 22.5% by weight (or 12% by weight) of an overbasic metal cleaner solubilized in a liquid diluent; (ii) 0.2 to 8.0% by weight (or 0.5 to 5% by weight) of an oxygenation accelerator (e.g., alcohol and / or organic acid); and (iii) 1 to 15% by weight (or 2 to 8% by weight) of water to form the hybrid grease.

19. The method according to claim 18, wherein the mixture from step (I) is mixed and heated at 70 to 90°C for 1 to 2 hours.

20. The anhydrous grease in step (I) is 1540-1600 cm －１ The method according to claim 18 or 19, wherein the method has at least one FTIR spectral peak between the two.

21. The method according to any one of claims 18 to 20, comprising mixing the mixture from step (II) and heating it at 70 to 95°C for 1 to 2 hours.

22. The hybrid grease in step II is 850-900 (or 870-890) cm －１ The method according to any one of claims 18 to 21, having at least one FTIR spectral peak in the range of .

23. The hybrid grease according to any one of claims 17 to 22, wherein the dropping point of the hybrid grease is greater than 220°C (or 250°C or 300°C) as measured using a dropping point test (e.g., ASTM D2265, ISO 2176, or IP 396).

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