A lubricating grease, its preparation and use

Abstract

The application belongs to the technical field of lubricating grease, and particularly relates to a kind of lubricating grease and its preparation method and application. The components of the lubricating grease include, by weight, 100 parts of base oil; 25-35 parts of thickening agent; 4-8 parts of OD modified h-BN; 2-4 parts of monolein glyceride modified MoS2@ laminated mica; 3-5 parts of anti-rust agent; 0.4-0.8 parts of antioxidant; and 1-3 parts of dispersant. The application improves the dispersibility and stability of h-BN and MoS2@ laminated mica in the lubricating grease by using OD modified h-BN and monolein glyceride modified MoS2@ laminated mica, and the components cooperate with each other to promote the lubricating grease to have excellent wear resistance and other properties.

Description

Technical Field

[0001] This invention belongs to the field of lubricating grease technology. More specifically, it relates to a lubricating grease, its preparation method, and its application. Background Technology

[0002] Lubricating grease is a highly structured suspension, typically composed of 75%-80% base oil, 20%-25% thickener, and less than 1% additives. It disperses the thickener within the base oil and uses additives to improve performance. The lubrication process of grease is considered a dynamic change in its thickened microstructure accompanied by viscosity variations. When grease is subjected to mechanical stress, the thickener fibers retain their original shape due to their inherent elastic properties. However, as mechanical stress is continuously applied to the grease, the original microstructure easily deforms, leading to leakage of the base oil and providing lubrication to the contact areas.

[0003] CN118406519A discloses a high-temperature resistant bentonite grease composition and its preparation method. The grease composition includes a base oil, a modified polyurea thickener, a modified bentonite thickener, solid fillers, and other additives. It is prepared by encapsulating the base oil within a thickened framework structure formed by polyurea and bentonite in a high-temperature, low-pressure reactor. This invention utilizes epoxy-modified castor oil to obtain a grease with good oxidation stability, thus improving its overall stability. The synergistic effect of diphenylmethane diisocyanate and bentonite improves the high-temperature cone penetration of the grease, enhancing its high-temperature resistance. The synergistic effect of silane coupling agents and long-chain alkylamines increases the water contact angle of the grease, improving its hydrophobicity. The use of epoxy resin-modified bentonite thickener enhances the corrosion resistance of the grease. The use of MoS2 / CNTs compound with calcium carbonate as a synergistic filler significantly improves the wear resistance and friction reduction properties of the grease.

[0004] CN118580899A discloses a lubricating grease and its preparation method, wherein the components are as follows by weight percentage: base oil 79.31-81%, thickener 6.27-6.84%, antioxidant 0.2-0.3%, rust inhibitor 0.03-0.05%, anti-wear agent 1-3%, and modifier 8-13%; the base oil is a mixed naphthenic base oil; the modifier is polytetrafluoroethylene, hydrophobic silica, and hydrophilic silica in a weight ratio of 8-10:1-2:0.5-1. Adding polytetrafluoroethylene (PTFE) at 200–210℃ to participate in lithium soap formation results in a more compact grease skeleton structure and better colloidal stability. This balances low-temperature performance with improved dropping point and reduced oil separation. Rapid cooling to 170–180℃ adds hydrophilic silica to the grease skeleton structure, enhancing its ability to adsorb base oil and ensuring lower low-temperature torque while reducing high-temperature oil separation. Further cooling to 140–150℃ adds hydrophobic silica, forming a water- and oil-locking barrier on the outer layer. This prevents the grease from becoming unstable when exposed to water while improving its wear resistance.

[0005] CN118146852A discloses a rust-preventive and wear-resistant composite soap-based grease and its preparation method. The rust-preventive and wear-resistant composite soap-based grease comprises the following raw materials in parts by weight: 80-92 parts base oil, 5-12 parts oxidized paraffin, 2-5 parts synthetic fatty acids, 3-8 parts alkaline reaction reagent, 1-5 parts anti-wear agent, and 0.2-2 parts antioxidant. The preparation method is as follows: the base oil is heated to 40-50℃, oxidized paraffin and synthetic fatty acids are added, and the mixture is stirred evenly to obtain a preliminary mixture; the alkaline reaction reagent is dissolved in water to obtain an alkaline solution; the alkaline solution is added dropwise to the preliminary mixture and mixed evenly to obtain a final mixture; the mixture is subjected to saponification at a higher temperature, dehydration, high-temperature refining, grinding, and maintaining the temperature at 80-100℃; anti-wear agent and antioxidant are added, and the mixture is mixed evenly and homogenized to obtain the finished product. It simultaneously possesses advantages such as good rust prevention, good wear resistance, high-temperature resistance, good shear stability, long-lasting lubrication, and long service life.

[0006] CN117143655A discloses a method for preparing a low-friction, high-wear-resistant grease, comprising the following steps: 1) preparing a graphene polyalphaolefin lubricating oil with good dispersibility and stability, and dividing it into two portions; 2) heating one portion of the prepared graphene polyalphaolefin lubricating oil to 80-100°C, adding stearic acid and diacid sequentially, and stirring continuously until uniformly mixed to obtain a mixed solution; 3) preheating a lithium hydroxide aqueous solution to 40°C, and then slowly adding it to the mixed solution, heating and maintaining the temperature until the saponification reaction is complete; 4) adding the other portion of the prepared graphene polyalphaolefin lubricating oil, and heating to 210°C for high-temperature refining; 5) after high-temperature refining, cooling to room temperature, and performing 3-4 grinding homogenization cycles to obtain the final product. The grease prepared by this invention has a high dropping point, good pumpability, high thermal stability and colloidal stability, and high specific heat capacity. During equipment operation, it also exhibits excellent mechanical stability and anti-friction properties, making it an excellent high-performance lubricating material.

[0007] As can be seen from the above literature, adding additives to grease can improve its wear resistance and other properties. This invention provides a novel grease with excellent wear resistance and other comprehensive properties. Summary of the Invention

[0008] The technical problem to be solved by this invention is to overcome the defects and deficiencies of the existing technology and provide a lubricating grease, its preparation method, and its application. By weight, the components of the lubricating grease include: 100 parts base oil; 25-35 parts thickener; 4-8 parts OD-modified h-BN; 2-4 parts monooleate-modified MoS2@lamellar mica; 3-5 parts rust inhibitor; 0.4-0.8 parts antioxidant; and 1-3 parts dispersant. This invention improves the dispersibility and stability of h-BN and MoS2@lamellar mica in the lubricating grease through OD-modified h-BN and monooleate-modified MoS2@lamellar mica, and through the synergistic effect of the components, promotes excellent wear resistance and other properties in the lubricating grease.

[0009] The purpose of this invention is to provide a method for preparing lubricating grease.

[0010] Another object of the present invention is to provide an application of a lubricating grease.

[0011] The above-mentioned objective of this invention is achieved through the following technical solution:

[0012] A lubricating grease, comprising, by weight:

[0013] 100 parts base oil;

[0014] Thickener 25-35 parts;

[0015] OD-modified h-BN 4-8 parts;

[0016] 2-4 parts of glyceryl monooleate modified MoS2@lamellar mica;

[0017] 3-5 parts rust inhibitor;

[0018] Antioxidant 0.4–0.8 parts;

[0019] Dispersant 1 to 3 parts.

[0020] Preferably, the base oil is PAO8 and PAO40, with a mass ratio of 1:3; the thickener is the reaction product of diphenylmethane diisocyanate and cyclohexylamine; and the mass ratio of diphenylmethane diisocyanate to cyclohexylamine is (2-3):1.

[0021] Preferably, the rust inhibitor is neutral dialkylnaphthalene sulfonate calcium, the antioxidant is zinc dipentyl dithiocarbamate or carbamate, and the dispersant is oleamide or erucamide.

[0022] In a preferred embodiment, the preparation method of the OD-modified h-BN includes the following steps:

[0023] (1) Place hexagonal boron nitride into DMF and sonicate at room temperature for 7-9 hours. Then filter, wash, and dry at 80-100℃ for 8-12 hours to obtain stripped boron nitride.

[0024] (2) The boron nitride and oleic acid diethanolamide obtained in step (1) are heated and refluxed at 140-150℃ for 4-6 hours, cooled to room temperature, and then the product is washed with ethanol more than three times and dried under vacuum at 60-90℃ for 6-10 hours to obtain OD modified h-BN.

[0025] Preferably, in step (2), the mass ratio of boron nitride to oleic acid diethanolamide is 1:10.

[0026] A further preferred embodiment of the preparation method of glyceryl monooleate modified MoS2@lamellar mica includes the following steps:

[0027] (1) First, disperse micron-sized sericite powder in anhydrous ethanol, stir evenly and then ultrasonically disperse it. Then, peel the mica powder into thin mica sheets, filter, and vacuum dry at 70-90℃ to constant weight to obtain sheet mica.

[0028] (2) The lamellar mica, ammonium molybdate, thioacetamide and urea obtained in step (1) are ultrasonically dispersed in deionized water, and then subjected to hydrothermal reaction. After washing, they are vacuum dried at 70-90℃ to constant weight to obtain MoS2@lamellar mica.

[0029] (3) Place monooleic glycerol and MoS2@lamellar mica into a high-energy ball mill and ball mill at 450-550 rpm for 8-12 hours to obtain monooleic glycerol modified MoS2@lamellar mica.

[0030] Preferably, in step (2), the mass ratio of the lamellar mica, ammonium molybdate, thioacetamide and urea obtained in step (1) is 100:2:1.0~1.4:5~7; the hydrothermal reaction is carried out at 180~240℃ for 20~30h.

[0031] Preferably, in step (3), the mass ratio of the monooleic glyceride to MoS2@lamellar mica is 1:50-60.

[0032] The method for preparing a lubricating grease as described above includes the following steps:

[0033] (1) Dissolve cyclohexylamine in ethanol, then add diphenylmethane diisocyanate, stir evenly, then heat to 50-70℃ and react for 30-40 min, filter, and dry at 60-80℃ to constant weight to obtain thickener;

[0034] (2) Then add the base oil and thickener to the reactor, stir thoroughly and heat to 170-180°C, refine for 1-2 hours, cool to 70-80°C, add the remaining raw materials, stir for 20-40 minutes, cool, grind and homogenize to obtain the grease.

[0035] Based on the above-described application of lubricating grease in bearings.

[0036] The present invention has the following beneficial effects:

[0037] This invention improves the dispersion stability of h-BN in grease by peeling off h-BN and then modifying it with oleic acid diethanolamide, thereby enhancing the grease's wear resistance and other properties. Similarly, by peeling mica powder into thin mica flakes, loading MoS2, and then modifying it with monooleic glycerol esters, the dispersibility and stability of MoS2@lamellar mica in grease are improved, thus enhancing the grease's lubrication performance and reducing wear rate. The grease prepared by this invention exhibits excellent overall properties, including good wear resistance. Detailed Implementation

[0038] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0039] The base oils are PAO8 and PAO40, with a mass ratio of PAO8 to PAO40 of 1:3.

[0040] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0041] Example 1

[0042] A lubricating grease, comprising, by weight:

[0043] 100 parts base oil;

[0044] Thickener (the thickener is the reaction product of diphenylmethane diisocyanate and cyclohexylamine; the mass ratio of diphenylmethane diisocyanate to cyclohexylamine is 2.5:1) 30 parts;

[0045] OD-modified h-BN 6 parts;

[0046] Three parts of glyceryl monooleate modified MoS2@lamellar mica;

[0047] Rust inhibitor (neutral dialkylnaphthalene sulfonate calcium) 4 parts;

[0048] Antioxidant (zinc dipentyl dithiocarbamate) 0.6 parts;

[0049] Dispersant (oleic amide) 2 parts.

[0050] The preparation method of the OD-modified h-BN includes the following steps:

[0051] (1) 100g of hexagonal boron nitride was placed in 200mL of DMF and sonicated at room temperature for 8h. Then it was filtered, washed, and dried at 90℃ for 10h to obtain the stripped boron nitride.

[0052] (2) 10g of boron nitride obtained in step (1) and 100g of oleic acid diethanolamide were heated and refluxed at 145℃ for 5h, cooled to room temperature, and the product was washed with ethanol more than three times and dried under vacuum at 80℃ for 8h to obtain OD modified h-BN.

[0053] The preparation method of glyceryl monooleate modified MoS2@lamellar mica includes the following steps:

[0054] (1) First, disperse 100g of micron-sized sericite powder in 200mL of anhydrous ethanol, stir evenly and then ultrasonically disperse. Then peel the mica powder into thin mica sheets, filter, and vacuum dry at 80℃ to constant weight to obtain sheet mica.

[0055] (2) 100g of the lamellar mica obtained in step (1), 2g of ammonium molybdate, 1.2g of thioacetamide and 6g of urea were ultrasonically dispersed into 250mL of deionized water, and then hydrothermally reacted at 220℃ for 26h. After washing, the mixture was vacuum dried at 80℃ to constant weight to obtain MoS2@lamellar mica.

[0056] (3) 1g of monooleic glycerol and 55g of MoS2@lamellar mica were placed in a high-energy ball mill and milled at 500rpm for 10h. The ball milling beads were zirconium balls with a diameter of 3mm and the ball-to-material mass ratio was 110:1. Monooleic glycerol modified MoS2@lamellar mica was obtained.

[0057] The preparation method specifically includes the following steps:

[0058] (1) Dissolve 10g of cyclohexylamine in ethanol, then add 25g of diphenylmethane diisocyanate, stir evenly, then heat to 60℃ and react for 35min, filter, and dry at 70℃ to constant weight to obtain thickener.

[0059] (2) Then add the base oil and thickener to the reactor according to the weight, stir thoroughly and heat to 175°C, refine for 1.5 hours, cool down to 75°C, add the remaining raw materials, stir for 30 minutes, cool, grind and homogenize to obtain the grease.

[0060] Example 2

[0061] A lubricating grease, comprising, by weight:

[0062] 100 parts base oil;

[0063] Thickener (the thickener is the reaction product of diphenylmethane diisocyanate and cyclohexylamine; the mass ratio of diphenylmethane diisocyanate to cyclohexylamine is 2.5:1) 35 parts;

[0064] OD-modified h-BN 4 parts;

[0065] Four parts of glyceryl monooleate modified MoS2@lamellar mica;

[0066] Rust inhibitor (neutral dialkylnaphthalene sulfonate calcium) 3 parts;

[0067] Antioxidant (carbamate) 0.8 parts;

[0068] 1 part of dispersant (erucamide).

[0069] The preparation method of the OD-modified h-BN is the same as in Example 1.

[0070] The preparation method of glyceryl monooleate modified MoS2@lamellar mica includes the following steps:

[0071] (1) Same as Example 1;

[0072] (2) Disperse 100g of lamellar mica obtained in step (1), 2g of ammonium molybdate, 1.4g of thioacetamide and 7g of urea into 250mL of deionized water by ultrasonication, then react hydrothermally at 240℃ for 20h, then wash and dry under vacuum at 90℃ to constant weight to obtain MoS2@lamellar mica.

[0073] (3) 1g of monooleic glycerol and 60g of MoS2@lamellar mica were placed in a high-energy ball mill and ball milled at 550rpm for 8h. The ball milling beads were zirconium balls with a diameter of 3mm and the ball-to-material mass ratio was 110:1. Monooleic glycerol modified MoS2@lamellar mica was obtained.

[0074] The preparation method specifically includes the following steps:

[0075] (1) Same as Example 1;

[0076] (2) Then add the base oil and thickener to the reactor according to the weight, stir thoroughly and heat to 180°C, refine for 1 hour, cool down to 80°C, add the remaining raw materials, stir for 20 minutes, cool, grind and homogenize to obtain the grease.

[0077] Example 3

[0078] A lubricating grease, comprising, by weight:

[0079] 100 parts base oil;

[0080] Thickener (the thickener is the reaction product of diphenylmethane diisocyanate and cyclohexylamine; the mass ratio of diphenylmethane diisocyanate to cyclohexylamine is 2.5:1) 25 parts;

[0081] OD-modified h-BN 8 parts;

[0082] Two parts of glyceryl monooleate modified MoS2@lamellar mica;

[0083] Rust inhibitor (neutral dialkylnaphthalene sulfonate calcium) 5 parts;

[0084] Antioxidant (zinc dipentyl dithiocarbamate) 0.4 parts;

[0085] Dispersant (erucamide) 3 parts.

[0086] The preparation method of the OD-modified h-BN is the same as in Example 1.

[0087] The preparation method of glyceryl monooleate modified MoS2@lamellar mica includes the following steps:

[0088] (1) Same as Example 1;

[0089] (2) Disperse 100g of lamellar mica obtained in step (1), 2g of ammonium molybdate, 1.0g of thioacetamide and 5g of urea into 250mL of deionized water by ultrasonication, then react hydrothermally at 180℃ for 30h, then wash and vacuum dry at 70℃ to constant weight to obtain MoS2@lamellar mica.

[0090] (3) 1g of monooleic glycerol and 50g of MoS2@lamellar mica were placed in a high-energy ball mill and ball milled at 450rpm for 12h. The ball milling beads were zirconium balls with a diameter of 3mm and the ball-to-material mass ratio was 110:1. Monooleic glycerol modified MoS2@lamellar mica was obtained.

[0091] The preparation method specifically includes the following steps:

[0092] (1) Same as Example 1;

[0093] (2) Then add the base oil and thickener to the reactor according to the weight, stir thoroughly and heat to 170°C, refine for 2 hours, cool down to 70°C, add the remaining raw materials, stir for 40 minutes, cool, grind and homogenize to obtain the grease.

[0094] Comparative Example 1

[0095] Except for the difference between Comparative Example 1 and Example 1, all other steps and conditions are the same, except that an equal amount of h-BN is used to replace OD-modified h-BN. The preparation process and conditions of h-BN are the same as in Example 1.

[0096] Comparative Example 2

[0097] Comparative Example 2 is identical to Example 1 in all steps and conditions except that an equal amount of MoS2@lamellar mica is used to replace glyceryl monooleate-modified MoS2@lamellar mica. The preparation process and conditions of the MoS2@lamellar mica are the same as in Example 1.

[0098] Comparative Example 3

[0099] Comparative Example 3 differs from Example 1 in all steps and conditions except that an equal amount of monooleate-modified lamellar mica is used instead of monooleate-modified MoS2@lamellar mica. The preparation method of the monooleate-modified lamellar mica includes the following steps:

[0100] The preparation method of glyceryl monooleate modified lamellar mica includes the following steps:

[0101] (1) First, disperse 100g of micron-sized sericite powder in 200mL of anhydrous ethanol, stir evenly and then ultrasonically disperse. Then peel the mica powder into thin mica sheets, filter, and vacuum dry at 80℃ to constant weight to obtain sheet mica.

[0102] (2) 1g of monooleic glycerol and 55g of the lamellar mica obtained in step (1) were placed into a high-energy ball mill and ball milled at 500 rpm for 10 hours. The ball milling beads were zirconium balls with a diameter of 3mm and the ball-to-material mass ratio was 110:1. Monooleic glycerol modified MoS2@lamellar mica was obtained.

[0103] Comparative Example 4

[0104] Comparative Example 3 is identical to Example 1 in all steps and conditions except that: 9 parts of OD-modified h-BN were used; and it does not contain monooleic glycerol-modified MoS2@lamellar mica.

[0105] The performance of the greases prepared in Examples 1-3 and Comparative Examples 1-4 was tested, and the specific results are shown in Table 1:

[0106] Table 1

[0107]

[0108] As can be seen from the above data, the grease prepared by this invention can effectively reduce friction and wear.

[0109] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A lubricating grease, characterized in that: The components of the grease, by weight, include: 100 parts base oil; Thickener 25-35 parts; 4-8 parts of oleic acid diethanolamide modified hexagonal boron nitride; 2-4 parts of glyceryl monooleate modified MoS2@lamellar mica; 3-5 parts rust inhibitor; Antioxidant 0.4–0.8 parts; 1-3 parts dispersant; The preparation method of the oleic acid diethanolamide modified hexagonal boron nitride includes the following steps. (1) Place hexagonal boron nitride into DMF and sonicate at room temperature for 7-9 hours. Then filter, wash, and dry at 80-100℃ for 8-12 hours to obtain stripped boron nitride. (2) The stripped boron nitride and oleic acid diethanolamide obtained in step (1) are heated and refluxed at 140-150℃ for 4-6 hours, cooled to room temperature, and then the product is washed with ethanol more than three times and dried under vacuum at 60-90℃ for 6-10 hours to obtain oleic acid diethanolamide modified hexagonal boron nitride. The preparation method of glyceryl monooleate modified MoS2@lamellar mica includes the following steps: (1) First, disperse micron-sized sericite powder in anhydrous ethanol, stir evenly and then ultrasonically disperse it. Then, peel the sericite powder into thin mica sheets, filter them, and vacuum dry them at 70-90℃ to constant weight to obtain sheet mica. (2) The lamellar mica, ammonium molybdate, thioacetamide and urea obtained in step (1) are ultrasonically dispersed in deionized water, and then subjected to hydrothermal reaction. After washing, they are vacuum dried at 70-90℃ to constant weight to obtain MoS2@lamellar mica. (3) Place monooleic glycerol and MoS2@lamellar mica into a high-energy ball mill and ball mill at 450-550 rpm for 8-12 hours to obtain monooleic glycerol modified MoS2@lamellar mica.

2. The lubricating grease according to claim 1, characterized in that: The base oils are PAO8 and PAO40, with a mass ratio of 1:3; the thickener is the reaction product of diphenylmethane diisocyanate and cyclohexylamine, with a mass ratio of (2-3):

1.

3. The lubricating grease according to claim 1, characterized in that: The rust inhibitor is neutral dialkylnaphthalene sulfonate calcium, the antioxidant is zinc dipentyl dithiocarbamate or carbamate, and the dispersant is oleamide or erucamide.

4. The lubricating grease according to claim 1, characterized in that: The mass ratio of the stripped boron nitride to oleic acid diethanolamide is 1:

10.

5. The lubricating grease according to claim 1, characterized in that: The mass ratio of the lamellar mica, ammonium molybdate, thioacetamide, and urea is 100:2:1.0-1.4:5-7; the hydrothermal reaction is carried out at 180-240℃ for 20-30 hours.

6. The lubricating grease according to claim 1, characterized in that: The mass ratio of monooleic glyceride to MoS2@lamellar mica is 1:50-60.

7. The method for preparing the lubricating grease according to any one of claims 1-6, characterized in that: The preparation method includes the following steps: (1) Dissolve cyclohexylamine in ethanol, then add diphenylmethane diisocyanate, stir evenly, then heat to 50-70℃ and react for 30-40 min, filter, and dry at 60-80℃ to constant weight to obtain thickener; (2) Then add the base oil and thickener to the reactor, stir thoroughly and heat to 170-180°C, refine for 1-2 hours, cool to 70-80°C, add the remaining raw materials, stir for 20-40 minutes, cool and grind to homogenize, and obtain the grease.

8. The application of the grease according to any one of claims 1-6 in bearings.

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