Grease composition and method for producing the same

Abstract

The present application provides a kind of grease composition and its preparation method.The grease composition of the present application includes the following components based on the total weight of the grease composition: 65% to 90% base oil, 5% to 30% bentonite thickener, 0.1% to 5% multifunctional additive, the multifunctional additive includes organic sulfur phosphorus compound as shown in formula (I): wherein the definition of each group is described in the specification.The grease composition of the present application has excellent extreme pressure and wear resistance, oxidation resistance, corrosion resistance and colloidal stability.

Description

Technical Field

[0001] This invention relates to a grease composition, and more particularly to a bentonite-based grease composition. Background Technology

[0002] With advancements in technology and stringent environmental regulations, lubricating grease additives are trending towards "compound and trace-dosage" formulations. An increasing number of compound additives are emerging, offering the benefits of multiple additives in one, enhancing synergistic effects, reducing additive dosage, and lowering costs. Bentonite grease, as an important lubricating material, exhibits poor sensitivity to additives due to the significant impact of different additive systems on its colloidal stability. Therefore, there is an urgent need for multifunctional additives suitable for use in bentonite greases.

[0003] CN 106317109A discloses a thiophosphate type extreme pressure anti-wear agent, which exhibits good rust prevention, thermal stability, and hydrolytic stability, but its anti-wear and friction-reducing properties are not superior to those of existing technologies. CN102260572B discloses a phosphorus-nitrogen type extreme pressure anti-wear agent, which has good antioxidant, rust prevention, and corrosion prevention properties and can be used as a multifunctional additive for industrial lubricating greases. However, it can only be used as a supplement to sulfur-phosphorus composite extreme pressure anti-wear agents, and it does not exhibit good extreme pressure anti-wear performance on its own.

[0004] Currently, phosphorus-containing additives exhibit good anti-wear and friction-reducing properties, but lack strong antioxidant properties. The trend in grease additive development is towards multi-functionality. Developing multi-functional additives can improve additive performance, reduce the variety and amount of additives in the formulation system, and improve the colloidal stability of bentonite greases. Summary of the Invention

[0005] This invention proposes a lubricating grease composition and its preparation method.

[0006] The grease composition of the present invention, based on the total weight of the grease composition, comprises the following components: 65% to 90% base oil, 5% to 30% bentonite thickener, and 0.1% to 5% multifunctional additive, wherein the multifunctional additive comprises an organosulfur-phosphorus compound as shown in formula (I):

[0007]

[0008] In formula (I), there are a L groups and b sulfur-containing phosphorus groups, where a is an integer between 1 and 8, and b is an integer between 1 and 10. The a L groups may be the same as or different from each other, and each is independently selected from the groups shown in formula (II).

[0009]

[0010] In formula (II), HO is bonded to the benzene ring; y R groups are bonded to the benzene ring; y is selected from integers between 0 and 4; and the R groups are selected from H and C. 1-10 Straight-chain or branched alkyl groups; n is an integer between 1 and 5; R1 is independently selected from C 1-10 Straight-chain or branched alkylene groups; the R2s in the n repeating units may be the same or different from each other, and each is independently selected from single bonds and C bonds. 1-10 Straight-chain or branched alkylene groups; R3 is selected from H and C. 1-10 Straight-chain or branched alkyl; the A groups in the n repeating units may be the same or different from each other, and each is independently selected from the groups shown in formula (III) and formula (IV).

[0011]

[0012] The R4 groups are each independently selected from H and C. 1-10 Straight-chain or branched alkyl; * in formulas (III) and (IV) represents a bonding end that is bonded to formula (II);

[0013] In formulas (III) and (IV), △ represents the bonding end bonded to b sulfur-containing phosphorus groups; each of the X groups in the b sulfur-containing phosphorus groups may be the same as or different from each other, and each is independently selected from the bonding end bonded to a L group, H, OH, R', OR', SR'; each of the R0 groups in the b sulfur-containing phosphorus groups may be the same as or different from each other, and each is independently selected from H, OH, R', OR', SR'; wherein R' is selected from C 1-20 Straight-chain or branched alkyl groups, C 6-10 aryl group, with one or more C 1-10 Straight-chain or branched alkyl-substituted C 6-10 aryl, C 1-20 The R' is a heterohydrocarbon group containing an oxygen atom or a sulfur atom, wherein the R' is optionally substituted by one or more groups selected from halogens and hydroxyl groups;

[0014] In each thiophosphorus group, there is one or two X's selected from the binding ends that are bonded to the L group; the various groups in the organothiophosphorus compound conform to the bonding rules.

[0015] According to the present invention, preferably, in formula (I), a is an integer between 1 and 4, and b is an integer between 1 and 6; in formula (II), HO is located at the meta position on the chain containing R1 on the benzene ring, y is an integer between 1 and 3, y R groups are located at the para or ortho position on the chain containing R1 on the benzene ring, and the R groups are selected from C 1-4 Straight-chain or branched alkyl groups (preferably tert-butyl), n is an integer between 1 and 3, and R1 is independently selected from C1. 1-4 A straight-chain or branched alkylene group, wherein the R2 in each of the n repeating units is independently selected from single bonds and C bonds.1-4 Straight-chain or branched alkylene groups, R3 selected from H and C 1-4 Straight-chain or branched alkyl groups; each of the R4 groups is independently selected from H and C. 1-4 Straight-chain or branched alkyl groups; wherein R' is selected from C 1-10 Straight-chain or branched alkyl, phenyl, and compounded by one or more C 1-10 Straight-chain or branched alkyl-substituted phenyl, C 1-10 It contains heterohydrocarbon groups containing oxygen or sulfur atoms.

[0016] According to the present invention, when both X groups in each thiophosphoric group are selected from the binding ends that are bonded to the L group, the two X groups can be bonded to the same L group or to two different L groups respectively.

[0017] According to the present invention, the two bonding ends (i.e. the two *) in formula (III) or formula (IV) that are bonded to formula (II) can be bonded to the group in formula (II) in any manner, for example, they can be bonded to formula (II) in one direction or in the opposite direction.

[0018] In the context of this invention, the heteroalkyl group refers to a group whose carbon chain structure is interrupted by one or more (e.g., 1 to 5, 1 to 4, 1 to 3, 1 to 2, or 1) heterogroups selected from -Sx- and -O-, wherein x is an integer between 1 and 5 (preferably an integer between 1 and 4, more preferably 1, 2, or 3); the hydrocarbon group can be a straight-chain or branched alkyl, a straight-chain or branched cycloalkyl, a straight-chain or branched aryl, or a mixed hydrocarbon group containing two or more of the groups selected from alkyl, cycloalkyl, and aryl. From the perspective of structural stability, preferably, when multiple heterogroups are present, no two of the heterogroups are directly bonded together.

[0019] According to the present invention, examples of the organosulfur-phosphorus compounds include one or more of the following structural compounds:

[0020]

[0021]

[0022] According to the present invention, the method for preparing the organosulfur-phosphorus compound includes the following steps:

[0023] (1) React the compound shown in formula (α) with the peroxide;

[0024]

[0025] In formula (α), HO is bonded to the benzene ring; y R groups are bonded to the benzene ring; y is selected from integers between 0 and 4; and the R groups are selected from H and C. 1-10 Straight-chain or branched alkyl groups; n is an integer between 1 and 5; R1 is independently selected from C 1-10 Straight-chain or branched alkylene groups; the R2s in the n repeating units may be the same or different from each other, and each is independently selected from single bonds and C bonds. 1-10 Straight-chain or branched alkylene groups; R3 is selected from H and C. 1-10 Straight-chain or branched alkyl; the A" in the n repeating units may be the same as or different from each other, and each is independently selected from... The R4 groups therein are each independently selected from H and C. 1-10 Straight-chain or branched alkyl groups;

[0026] (2) React the reaction product of step (1) with the compound shown in formula (β) and collect the product;

[0027]

[0028] In formula (β), each X' group may be the same as or different from each other, and each is independently selected from H, OH, R', OR', SR'; R0 is selected from H, OH, R', OR', SR'; and R' is selected from C. 1-20 Straight-chain or branched alkyl groups, C 6-10 aryl group, with one or more C 1-10 Straight-chain or branched alkyl-substituted C 6-10 aryl, C 1-20 The R' is a heterohydrocarbon group containing an oxygen atom or a sulfur atom, wherein the R' is optionally substituted by one or more groups selected from halogens and hydroxyl groups; in formula (β), at least one X' group is selected from OH.

[0029] According to the present invention, preferably, HO is located at the meta position on the chain containing R1 on the benzene ring, y is an integer between 1 and 3, y R groups are located at the para or ortho position on the chain containing R1 on the benzene ring, and the R groups are selected from C 1-4 Straight-chain or branched alkyl groups (more preferably tert-butyl), n is an integer between 1 and 3, and R1 is independently selected from C1. 1-4 A straight-chain or branched alkylene group, wherein the R2 in each of the n repeating units is independently selected from single bonds and C bonds. 1-4 Straight-chain or branched alkylene groups, R3 selected from H and C 1-4 Straight-chain or branched alkyl groups; each of the R4 groups is independently selected from H and C. 1-4 Straight-chain or branched alkyl groups; wherein R' is selected from C 1-10 Straight-chain or branched alkyl, phenyl, and compounded by one or more C 1-10 Straight-chain or branched alkyl-substituted phenyl, C 1-10 It contains heterohydrocarbon groups containing oxygen or sulfur atoms.

[0030] According to the present invention, in step (1), the compound represented by formula (α) can be selected from cashew phenol and alkylated cashew phenol. The alkylated cashew phenol can be obtained by reacting cashew phenol with an alkylating agent, for example, by reacting cashew phenol with tert-butyl chloride to obtain tert-butylated cashew phenol.

[0031] According to the present invention, in step (1), the peroxide is preferably one or more of hydrogen peroxide, formic acid, peracetic acid, persulfonic acid, m-chloroperoxybenzoic acid, tert-butyl hydroperoxide, tert-butyl peracetic acid, methyl ethyl ketone peroxide, benzoyl peroxide and cyclohexanone peroxide, more preferably one or more of hydrogen peroxide, formic acid, peracetic acid and persulfonic acid.

[0032] According to the present invention, in step (2), the compound represented by formula (β) can be selected from alkoxythiophosphoric acid, aryloxythiophosphoric acid, alkylthiophosphoric acid, arylthiophosphoric acid, alkoxythiophosphonic acid, alkylthiophosphonic acid, hydroxy-substituted alkylthiophosphoric acid, etc. For example, phenylthiophosphonic acid, ethylthiophosphonic acid, phenoxythiophosphoric acid, ethylthiophosphoric acid, hydroxymethylthiophosphonic acid, phenylthiomethoxythiophosphoric acid, thiophosphoric acid, or one or more of these can be selected.

[0033] According to the present invention, the equivalence ratio between the compound represented by formula (α) and the peroxide and the compound represented by formula (β) is preferably 1:0.5 to 10:0.5 to 10, more preferably 1:2 to 5:2 to 5.

[0034] According to the present invention, the reaction temperature of step (1) is preferably 0 to 100°C, more preferably 20 to 80°C; the reaction temperature of step (2) is preferably 50 to 150°C, more preferably 70 to 120°C.

[0035] According to the present invention, a catalyst may be added in step (1), preferably an acidic catalyst, more preferably a Lewis acid catalyst, such as one or more of concentrated sulfuric acid, zinc chloride, aluminum trichloride, benzenesulfonic acid and titanate, and the amount of catalyst added is preferably 0.01% to 3% of the compound shown in formula (α). After the reaction in step (1) is completed, the catalyst may be removed by alkaline washing or water washing.

[0036] According to the present invention, a catalyst may be added in step (2), preferably an acidic catalyst, more preferably a Lewis acid catalyst, such as one or more of concentrated sulfuric acid, zinc chloride, aluminum trichloride, benzenesulfonic acid and titanate, and the amount of catalyst added is preferably 0.5% to 10% of the compound shown in formula (α). After the reaction in step (2) is completed, the catalyst may be removed by alkaline washing or water washing.

[0037] According to the present invention, the reaction steps (1) and (2) can be carried out in the presence of a diluent and / or a solvent, or without the use of a diluent and / or a solvent.

[0038] According to the present invention, the diluent may be selected from one or more of API Group I, II, III, IV and V base oils. Common products or grades include 150SN, 200SN, 350SN, 500SN, 650SN, 150BS, HVI-100, HVI-150, HVI-200, HVI-350, HVI-400, HVI-500, HVI-150BS, PAO4, PAO6, PAO8, PAO10, alkylbenzene, alkylnaphthalene, etc.

[0039] According to the present invention, the solvent may be water, C 6-20 Aromatic hydrocarbons (such as benzene, toluene, xylene, and cumene), C 6-10 Alkanes (such as n-hexane, cyclohexane, and petroleum ether), solvent gasoline, etc. These solvents may be used individually, or in combination of two or more. The solvents may be removed after the reaction is complete, using methods known to those skilled in the art, such as under normal or reduced pressure.

[0040] According to a particular embodiment of the present invention, the diluent and / or solvent may be added at any stage of the reaction step in the amounts conventional in the art, without particular limitation.

[0041] According to the present invention, the reaction can be carried out under the protection of an inert gas atmosphere. Examples of inert gases include nitrogen and argon, and there is no particular limitation.

[0042] According to the present invention, the aforementioned preparation method can produce a single organosulfur phosphorus compound, a mixture of multiple organosulfur phosphorus compounds, or a mixture of one or more organosulfur phosphorus compounds with the aforementioned diluent (if used) as the reaction product. These reaction products are all contemplated by the present invention, and their different forms do not affect the achievement of the effects of the present invention. Therefore, in the context of this specification, these reaction products are collectively referred to as organosulfur phosphorus compounds without distinction. In view of this, according to the present invention, there is no absolute necessity for further purification of the reaction product or for further separation of an organosulfur phosphorus compound with a specific structure from the reaction product. Of course, such purification or separation is preferred for further enhancing the intended effects of the present invention, but is not necessary for the present invention. Nevertheless, methods for purification or separation, such as column chromatography or preparative chromatography, can be cited as examples.

[0043] According to the present invention, the base oil is preferably a synthetic oil, and more preferably has a viscosity of 2 to 100 mm at 100°C. 2 The base oil is preferably 4-50 mm at 100℃. 2 / s of base oil. The synthetic oil includes one or more of polyalphaolefins, alkylbenzenes and alkylnaphthalenes, with common trade names including PAO 4, PAO 6, PAO 8, PAO 10, etc.

[0044] According to the present invention, the bentonite thickener comprises organic bentonite and a dispersant.

[0045] According to the present invention, the organobentonite can be any organobentonite in the prior art, such as modified montmorillonite, with common commercial brands including 881B. The organobentonite can swell in base oil to form a stable colloid or colloidal dispersion, exhibiting strong thickening ability, anti-emulsification properties, and thermal stability.

[0046] According to the present invention, the dispersant is a low molecular weight polar molecule, including but not limited to one or more of acetone, methanol, ethanol, and propylene carbonate. In one embodiment, the mass of the dispersant is preferably 10-40% of the mass of organobentonite, more preferably 15-30%. When the amount of dispersant is too low, below 10% of the amount of organobentonite, it cannot effectively promote dispersion, resulting in a low consistency of the prepared grease, and the organobentonite cannot effectively thicken the base oil. When the amount of dispersant is too high, above 40% of the amount of organobentonite, the prepared grease becomes significantly thinner, and the cone penetration increases.

[0047] According to the present invention, optionally, the grease composition comprises, by weight of total grease composition, 70% to 90% base oil, 9% to 25% bentonite thickener, and 0.2% to 5% multifunctional additive.

[0048] According to the present invention, the method for preparing the lubricating grease composition includes: adding a portion of base oil and all of the organic bentonite to a reaction vessel, stirring and heating to 70°C to 120°C, adding a dispersant, and stirring for 20 to 50 minutes; heating to 150 to 200°C for high-temperature refining for 5 to 20 minutes, and then adding the remaining base oil; cooling to 130°C or below, and adding an organic sulfur-phosphorus compound; and grinding into grease.

[0049] The bentonite grease composition of the present invention has excellent extreme pressure anti-wear, anti-oxidation, anti-corrosion and colloidal stability properties. Attached Figure Description

[0050] Figure 1 The infrared spectrum of the product of Example 2 is shown below.

[0051] Figure 2 The image shows the carbon NMR spectrum of the product from Example 2. Detailed Implementation

[0052] In this specification, the term "single bond" is sometimes used in the definition of a group. A "single bond" means that the group does not exist. For example, suppose the structural formula is -CH2-A-CH3, where group A is defined as selected from single bonds and methyl groups. Therefore, if A is a single bond, it means that group A does not exist, and the structural formula is correspondingly simplified to -CH2-CH3.

[0053] The present invention will be further illustrated by the following embodiments, but these are not intended to limit the scope of the invention.

[0054] The main raw materials used are as follows:

[0055] Cashew phenol, Shanghai Wujing Chemical Technology Co., Ltd., industrial products

[0056] Zinc chloride, Sinopharm Chemical Reagent Co., Ltd., analytical grade

[0057] Concentrated sulfuric acid, Sinopharm Chemical Reagent Co., Ltd., analytical grade.

[0058] Hydrogen peroxide (30%), Sinopharm Chemical Reagent Co., Ltd., analytical grade.

[0059] Formic acid, Sinopharm Chemical Reagent Co., Ltd., analytical grade

[0060] Phenylethiophosphonic acid, Sinopharm Chemical Reagent Co., Ltd., chemically pure

[0061] Ethiophosphonic acid, Sinopharm Chemical Reagent Co., Ltd., chemically pure

[0062] Ethiophosphoric acid, Sinopharm Chemical Reagent Co., Ltd., chemically pure

[0063] tert-butyl chloride, Sinopharm Chemical Reagent Co., Ltd., analytical grade

[0064] Toluene, Sinopharm Chemical Reagent Co., Ltd., analytical grade

[0065] PAO 6 synthetic oil, Shanghai Zejun Trading Co., Ltd., industrial products.

[0066] Organic bentonite, brand name 881B, was purchased from Hangzhou Lin'an Coating Additives & Chemicals Co., Ltd.; industrial grade propylene carbonate, analytical grade, was purchased from Sinopharm Chemical Reagents Beijing Co., Ltd.

[0067] T306, Zibo Huihua Petroleum Additives Co., Ltd., Industrial Product

[0068] T706, Nanjing Aubeck Fine Chemical Co., Ltd., Industrial Products

[0069] Antioxidant V81, Beijing Lifuruida Science & Trade Co., Ltd., Industrial Products

[0070] Example 1: Preparation of tert-butylated epoxy cashew phenol

[0071] Take 100g of cashew nut shell powder, 8g of formic acid, 0.3g of sulfuric acid, and 200g of hydrogen peroxide, and add them to a three-necked flask equipped with a mechanical stirrer, reflux condenser, and temperature control. Turn on the stirrer and heat. Maintain the reaction temperature at 70℃ and react for 3 hours. After the reaction is complete, cool down to obtain a brownish-red transparent liquid. Filter the reaction product and wash it with 5% KOH solution, then wash it with distilled water until neutral. Distill the organic phase under reduced pressure at 100Pa and 150℃ for 1 hour to remove water and unreacted raw materials, obtaining an orange-red transparent liquid epoxidized cashew nut shell powder.

[0072] 35g of epoxidized cashew nut shell phenol was dissolved in 100ml of acetone. After dissolution, the solution was transferred to a 250ml three-necked reaction flask, and 0.9g of zinc chloride catalyst was added. The mixture was stirred and heated. The reaction temperature was maintained at 60℃. 9.5g of tert-butyl chloride was slowly added dropwise to the reaction flask. After the addition was complete, the reaction was continued for 3 hours. After the reaction was completed, the temperature was lowered to obtain a brownish-red transparent liquid. The reaction product was filtered and washed with 5% KOH solution, then washed with distilled water until neutral. The product was then distilled under reduced pressure at 1000Pa and 120℃ for 1 hour to remove the solvent, water, and unreacted raw materials, yielding a brownish-red viscous liquid, tert-butylated epoxidized cashew nut shell phenol.

[0073] An example reaction formula for the above reaction is shown below.

[0074]

[0075] Example 2

[0076] 2g of the tert-butylated epoxy cashew phenol prepared in Example 1, 0.02g of concentrated sulfuric acid, 10g of water, and 100g of toluene were added to a three-necked flask equipped with a mechanical stirrer and a reflux condenser. The mixture was stirred, heated, and refluxed at 85°C for 1 hour. Then, 2g of phenylthiophosphonic acid was added dropwise. After the addition was complete, the reaction was continued under reflux for 5 hours, and then the reaction was stopped. The product was washed with water until neutral, and finally the solvent was evaporated to obtain the organosulfur-phosphorus compound W-01 of the present invention.

[0077] Since the reactants are a mixture of tert-butylated epoxy cashew phenols such as monoepoxy, diepoxy, and triepoxy, the reaction products are a mixture of numerous organosulfur and phosphorus compounds. Therefore, the following are some representative examples of the main reaction formulas for the reaction of tert-butylated epoxy cashew phenols with monoepoxy.

[0078]

[0079] The product prepared in Example 2 was subjected to infrared spectroscopy and nuclear magnetic resonance analysis. The infrared spectrum is shown in the figure. Figure 1 The analysis results are shown in Table 1, and the NMR spectra are shown in Table 1. Figure 2 The analysis results are shown in Table 2.

[0080] Table 1 Infrared analysis results of the products

[0081]

[0082] Table 1 shows that the product contains characteristic peaks such as C-OH stretching vibration peak, P=S stretching vibration peak, benzene ring skeleton stretching vibration peak, POC stretching vibration peak, and PC stretching vibration peak, which indicates that the synthesized product is the target compound.

[0083] Table 2. Results of NMR spectroscopy analysis of the products

[0084]

[0085] The C element assignments for the OH groups on the benzene ring in Table 2 indicate the presence of phenolic structures in the products; the C element assignments for PC indicate the presence of phenyl phosphide structures; the C element assignments for OC indicate the presence of ester groups on the alkyl chains; and the C element assignments for tert-butyl quaternary structures indicate the presence of tert-butyl structures. The C element assignments can indicate that the synthesized products are the target compounds.

[0086] Example 3

[0087] 2g of the tert-butylated epoxy cashew phenol prepared in Example 1, 0.01g of concentrated sulfuric acid, 10g of water, and 100g of toluene were added to a three-necked flask equipped with a mechanical stirrer and a reflux condenser. The mixture was stirred, heated, and refluxed at 95°C for 1 hour. Then, 3.2g of ethyl thiophosphonic acid was added dropwise. After the addition was complete, the reaction was refluxed for another 3 hours, and then the reaction was stopped. The product was washed with water until neutral, and finally the solvent was evaporated to obtain the organosulfur-phosphorus compound W-02.

[0088] Example 4

[0089] 2g of the tert-butylated epoxy cashew phenol prepared in Example 1, 0.05g of concentrated sulfuric acid, 10g of water, and 100g of toluene were added to a three-necked flask equipped with a mechanical stirrer and a reflux condenser. The mixture was stirred, heated, and refluxed at 110°C for 1 hour. Then, 2.5g of ethylthiophosphoric acid was added dropwise. After the addition was complete, the reaction was continued under reflux for 6 hours, at which point the reaction was stopped. The product was washed with water until neutral, and finally the solvent was evaporated to obtain the organosulfur-phosphorus compound W-03.

[0090] Example 5

[0091] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2150g of bentonite 881B was added to the reactor, stirred and heated, and 45g of propylene carbonate was slowly added dropwise at 100°C. The mixture was stirred for 30 minutes and then heated to 165°C for 10 minutes. 460g of PAO 6 synthetic oil was added, and the mixture was cooled to 130°C. 2.5g of W-01 prepared in Example 2 was added. The mixture was then ground three times with a three-roll mill to obtain the grease composition of the present invention. Its properties are shown in Table 3.

[0092] Example 6

[0093] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2 150g of bentonite 881B was added to the reactor, stirred and heated, and 45g of propylene carbonate was slowly added dropwise at 100°C. The mixture was stirred for 30 minutes and then heated to 165°C for 10 minutes. 460g of PAO 6 synthetic oil was added, and the mixture was cooled to 130°C. 2.5g of W-02 prepared in Example 3 was added. The mixture was then ground three times with a three-roll mill to obtain the grease composition of the present invention. Its properties are shown in Table 3.

[0094] Example 7

[0095] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2 150g of bentonite 881B was added to the reactor, stirred and heated, and 45g of propylene carbonate was slowly added dropwise at 100°C. The mixture was stirred for 30 minutes and then heated to 165°C for 10 minutes. 460g of PAO 6 synthetic oil was added, and the mixture was cooled to 130°C. 2.5g of W-03 prepared in Example 4 was added. The mixture was then ground three times with a three-roll mill to obtain the grease composition of the present invention. Its properties are shown in Table 3.

[0096] Example 8

[0097] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2 150g of bentonite 881B was added to the reactor, stirred and heated, and 45g of propylene carbonate was slowly added dropwise at 100°C. The mixture was stirred for 30 minutes and then heated to 165°C for 10 minutes. 460g of PAO 6 synthetic oil was added, and the mixture was cooled to 130°C. 25g of W-01 prepared in Example 2 was added, and the mixture was ground three times with a three-roll mill to obtain the grease composition of the present invention. Its properties are shown in Table 3.

[0098] Example 9

[0099] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2150g of bentonite 881B was added to the reactor, stirred and heated, and 45g of propylene carbonate was slowly added dropwise at 100°C. The mixture was stirred for 30 minutes and then heated to 165°C for 10 minutes. 460g of PAO 6 synthetic oil was added, and the mixture was cooled to 130°C. 35g of W-01 prepared in Example 2 was added, and the mixture was ground three times with a three-roll mill to obtain the grease composition of the present invention. Its properties are shown in Table 3.

[0100] Comparative Example 1

[0101] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2 150g of bentonite 881B was added to the reactor, stirred and heated, and 45g of propylene carbonate was slowly added dropwise at 100℃. The mixture was stirred for 30 minutes and then heated to 165℃ for 10 minutes. 460g of PAO 6 synthetic oil was added, and the mixture was cooled to 130℃ and 2.5g of T306 was added. The mixture was then ground three times with a three-roll mill to obtain a comparative grease composition. Its properties are shown in Table 4.

[0102] Comparative Example 2

[0103] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2 150g of bentonite 881B was added to the reactor, stirred and heated, and 45g of propylene carbonate was slowly added dropwise at 100℃. The mixture was stirred for 30 minutes and then heated to 165℃ for 10 minutes. 460g of PAO 6 synthetic oil was added, and the mixture was cooled to 130℃ and 2.5g of T706 was added. The mixture was then ground three times with a three-roll mill to obtain a comparative grease composition. Its properties are shown in Table 4.

[0104] Comparative Example 3

[0105] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2 150g of bentonite 881B was added to the reactor, stirred and heated. At 100℃, 45g of propylene carbonate was slowly added dropwise. The mixture was stirred for 30 minutes and then heated to 165℃ for 10 minutes. 460g of PAO 6 synthetic oil was added. The mixture was cooled to 130℃ and 1.5g of T306 and 1.0g of T706 were added. The mixture was then ground three times with a three-roll mill to obtain a comparative grease composition. Its properties are shown in Table 4.

[0106] Comparative Example 4

[0107] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2150g of bentonite 881B was added to the reactor, stirred and heated, and 45g of propylene carbonate was slowly added dropwise at 100℃. The mixture was stirred for 30 minutes and then heated to 165℃ for 10 minutes. 460g of PAO 6 synthetic oil was added, and the mixture was cooled to 130℃ and 2.5g of V81 was added. The mixture was then ground three times with a three-roll mill to obtain a comparative grease composition. Its properties are shown in Table 4.

[0108] Comparative Example 5

[0109] 400g of PAO 6 synthetic oil (viscosity 5.69mm at 100℃) 2 150g of bentonite 881B was added to the reactor, stirred and heated. At 100℃, 45g of propylene carbonate was slowly added dropwise. The mixture was stirred for 30 minutes and then heated to 165℃ for 10 minutes. 460g of PAO 6 synthetic oil was added. The mixture was cooled to 130℃ and 1.5g of T306, 0.5g of T706, and 0.5g of V81 were added. The mixture was then ground three times with a three-roll mill to obtain a comparative grease composition. Its properties are shown in Table 4.

[0110] Table 3. Evaluation of Lubricating Grease Performance

[0111]

[0112] Table 4 Comparison of Lubricating Grease Performance Evaluation

[0113]

Claims

1. A grease composition, based on the total weight of the grease composition, comprising the following components: 65%–90% base oil, 5%–30% bentonite thickener, and 0.1%–5% multifunctional additive, wherein the multifunctional additive comprises an organosulfur-phosphorus compound, said organosulfur-phosphorus compound being one or more of the following structural compounds: 。 2. The lubricating grease composition according to claim 1, characterized in that, The method for preparing the organosulfur-phosphorus compound includes the following steps: (1) To react (α) compound with peroxide; The (α) compound is tert-butylated cashew nut shell; the peroxide is selected from one or more of hydrogen peroxide, peroxyformic acid, peracetic acid, persulfonic acid, m-chloroperoxybenzoic acid, tert-butyl hydroperoxide, tert-butyl peracetic acid, methyl ethyl ketone peroxide, benzoyl peroxide and cyclohexanone peroxide. (2) React the reaction product of step (1) with compound (β) and collect the product; The (β) compound is selected from one or more of phenylthiophosphonic acid, ethylthiophosphonic acid, and ethylthiophosphoric acid.

3. The lubricating grease composition according to claim 2, characterized in that, The equivalence ratio between (α) compounds and peroxides and (β) compounds is 1:0.5~10:0.5~10.

4. The lubricating grease composition according to claim 2, characterized in that, The reaction temperature in step (1) is 0~100℃; the reaction temperature in step (2) is 50~150℃.

5. The lubricating grease composition according to any one of claims 1 to 4, characterized in that, The base oil is a synthetic oil; the bentonite thickener includes organic bentonite and a dispersant.

6. A method for preparing the lubricating grease composition of claim 5, comprising: Add some base oil and all of the organobentonite to the reactor, stir and heat to 70℃~120℃, add dispersant, stir for 20~50 min; heat to 150~200℃ for high-temperature refining for 5~20 min, then add the remaining base oil; cool to 130℃ or below, add organosulfur and phosphorus compounds; grind into grease.

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