High-temperature-resistant antioxidant lubricating grease as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of lubricating grease, and particularly relates to high-temperature-resistant antioxidant lubricating grease as well as a preparation method and application thereof. The high-temperature-resistant antioxidant lubricating grease provided by the invention comprises the following components in parts by weight: 120-160 parts of base oil; 5 to 7 parts of carbamido modified carbon nitride nanosheets; 20 to 30 parts of a thickening agent; 2 to 4 parts of a Ce-MOF / GO composite material; 5-7 parts of an antirust agent; 1-3 parts of an antioxidant; and 2-4 parts of a dispersant. According to the lubricating grease, the carbamido modified carbon nitride nanosheet has excellent thermal stability, the dispersion stability of the lubricating grease in the lubricating grease can be improved, the wear resistance and the bearing capacity of the lubricating grease can be promoted by loading the Ce-MOF material on the GO surface, and meanwhile, the Ce-MOF material adheres to the rubbed surface to form a protective film, so that the lubricating grease has good wear resistance. By compounding with GO, a synergistic and complementary effect is achieved, and improvement of the performance of the lubricating grease is promoted together. The prepared lubricating grease has the properties of high temperature resistance, lubricity, oxidation resistance and the like, and is wide in application and good in application prospect.

Description

[0001] Technical Field: This invention belongs to the field of lubricating grease technology. More specifically, it relates to a high-temperature resistant and antioxidant lubricating grease, its preparation method, and its application. Background Technology

[0002] During mechanical operation, friction and wear of components lead to significant energy loss and wear of parts. The proper use of lubricants is the most effective way to reduce friction and wear. Grease is a special type of lubricant, appearing as a semi-solid or solid, composed of base oil, thickener, and additives. Compared to lubricating oil, grease has unique advantages: it adheres to the surface of the lubricated area as a semi-solid, preventing leakage and splashing; it covers the surface of the lubricated area, acting as a seal to prevent external dust, moisture, and gases from entering and contaminating the friction surfaces, and also provides rust prevention; as a semi-solid, it adheres to the friction surfaces without requiring constant replenishment like fluid lubricating oil, making it suitable for sealing devices or other machines where frequent lubrication is not advisable; it forms a thicker oil film during lubrication, significantly thicker under low-speed conditions; and it does not settle or separate after the addition of solid lubricants. Grease is a colloidal system with non-Newtonian fluid properties. Base oil and thickener constitute the main body of the grease, while a small amount of additives are dispersed within it to improve its performance. Therefore, lubricating grease is an important product for the maintenance and lubrication of mechanical equipment and has broad application prospects.

[0003] CN119709292A discloses a lubricating grease, its preparation method, and its application. The lubricating grease is prepared from raw materials comprising the following mass percentages: 30-65% basic calcium sulfonate, 30-55% base oil, 1-8% calcium sulfonate crystal form conversion agent, and 0.5-3% thickener; the base oil has a kinematic viscosity of 10-100 mm² / s at 100°C; and the thickener has a viscosity-average molecular weight of 35,000-100,000. This lubricating grease utilizes a relatively high-viscosity base oil and thickener, effectively improving its adhesion and water erosion resistance, while also exhibiting good high-temperature resistance and anti-wear properties. It can effectively reduce the friction coefficient of the expansion tube during the expansion process, and due to the improved lubrication conditions, extends the service life of the expansion cone and reduces the risk of operational failures.

[0004] CN118931626A discloses a high-temperature resistant grease for gears and its preparation method. The grease includes the following raw materials: synthetic oil PAO, ester base oil, thickener, antioxidant, extreme pressure anti-wear agent, rust inhibitor, and Peek-based composite additive. The Peek-based composite additive is prepared by mixing polyether ether ketone with hydrogenated styrene isoprene copolymer, impregnating it with porous polyester-silica composite microspheres, and then drying. The preparation method includes the following steps: mixing synthetic oil PAO and ester base oil, heating and stirring, adding antioxidant and heating and stirring again; cooling, adding extreme pressure anti-wear agent and rust inhibitor, stirring, adding thickener and Peek-based composite additive, mixing and stirring, cooling, and obtaining the grease. This application has the characteristics of improving the dropping point of the grease for household appliance gears, thereby improving its high-temperature resistance, and preventing it from softening and flowing out under high-temperature working conditions, thus affecting the lubrication effect.

[0005] By adding additives to grease, the wear resistance and lubrication properties of grease can be effectively improved. This invention provides a high-temperature resistant and antioxidant grease, which has excellent lubrication performance at high temperatures and good antioxidant properties by adding antioxidants. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the defects and deficiencies of existing technologies and provide a high-temperature resistant and antioxidant lubricating grease, its preparation method, and its application. The high-temperature resistant and antioxidant lubricating grease of this invention comprises, by weight, the following components: 120-160 parts base oil; 5-7 parts urea-modified carbon nitride nanosheets; 20-30 parts thickener; 2-4 parts Ce-MOF / GO composite material; 5-7 parts rust inhibitor; 1-3 parts antioxidant; and 2-4 parts dispersant. This invention utilizes urea-modified carbon nitride nanosheets to give it excellent thermal stability and improve its dispersion stability in the lubricating grease. By loading Ce-MOF material onto the GO surface, the anti-wear performance and load-bearing capacity of the lubricating grease are promoted. Simultaneously, the Ce-MOF material adheres to the friction surface to form a protective film, and through its compounding with GO, it plays a synergistic and complementary role, jointly promoting the improvement of lubricating grease performance. The lubricating grease prepared by this invention has high-temperature resistance, lubricity, and antioxidant properties, and is widely applicable with good application prospects.

[0007] The purpose of this invention is to provide a high-temperature resistant and antioxidant lubricating grease.

[0008] Another objective of this invention is to provide a method for preparing a high-temperature resistant and antioxidant lubricating grease.

[0009] Another objective of this invention is to provide an application of a high-temperature resistant and antioxidant lubricating grease.

[0010] The above-mentioned objective of this invention is achieved through the following technical solution:

[0011] A high-temperature resistant and antioxidant lubricating grease, comprising the following components by weight:

[0012] 120-160 parts base oil;

[0013] 5-7 parts of urea-modified carbon nitride nanosheets;

[0014] Thickener 20-30 parts;

[0015] 2-4 parts of Ce-MOF / GO composite material;

[0016] 5-7 parts rust inhibitor;

[0017] Antioxidant 1-3 parts;

[0018] Dispersant 2-4 parts.

[0019] Furthermore, the base is PAO6 and PAO40, with a mass ratio of 2:3; the thickener is obtained by reacting aniline with toluene-2,4-diisocyanate, with a mass ratio of aniline to toluene-2,4-diisocyanate of 0.5~1.5:1.

[0020] In this invention, a preferred embodiment of the method for preparing the urea-modified carbon nitride nanosheets includes the following steps:

[0021] (1) Disperse carbon nitride nanosheets in ethylene glycol, add urea, continue stirring, then carry out a solvothermal reaction, filter, wash, and vacuum dry to constant weight to obtain amino-modified carbon nitride nanosheets.

[0022] (2) The amino-modified carbon nitride nanosheets and dicyclohexylmethane diisocyanate obtained in step (1) are dispersed in toluene, stirred at room temperature under nitrogen protection, filtered, washed, and then product A is obtained. Then product A is dispersed in toluene, and then aniline is added. Then the reaction is stirred under nitrogen protection, filtered, washed, and vacuum dried to constant weight to obtain urea-modified carbon nitride nanosheets.

[0023] Preferably, in step (1), the mass ratio of urea to carbon nitride nanosheets is 2~3:1; the stirring time is 20~40 min; the solvothermal reaction conditions are 8~12 h at 140~200 °C; and the vacuum drying temperature is 60~90 °C.

[0024] Preferably, in step (2), the mass ratio of the aminated carbon nitride nanosheets to dicyclohexylmethane diisocyanate is 1:3~7; and the mass ratio of product A to aniline is 1:0.2~0.6.

[0025] Preferably, in step (2), the room temperature stirring time is 10~20h, the stirring reaction conditions are stirring reaction at 30~50℃ for 10~18h, and the drying temperature is 60~90℃.

[0026] In a further preferred embodiment of the present invention, the preparation method of the Ce-MOF / GO composite material includes the following steps:

[0027] Graphene oxide and cerium salt were dispersed in ethanol and water and stirred for 20-40 min. Then 2-aminoterephthalic acid was added and stirred for 10-30 min. The mixture was then hydrothermally reacted at 130-150 °C for 6-14 h. After filtration and washing, the mixture was vacuum dried at 60-90 °C to constant weight to obtain Ce-MOF / GO composite material.

[0028] Preferably, the volume ratio of ethanol to water is 4:1; the ratio of graphene oxide, cerium salt and 2-aminoterephthalic acid is 1g:3~5mmol:5~9mmol, and the cerium salt is one of cerium nitrate, cerium acetate and cerium chloride.

[0029] The preparation method of the high-temperature resistant and antioxidant lubricating grease described above specifically includes the following steps:

[0030] (1) Dissolve aniline in ethanol, then add toluene-2,4-diisocyanate, stir evenly, react at 2000 rpm to 4000 rpm and 50 to 70 °C for 20 to 60 min, filter, and vacuum dry at 60 to 80 °C to constant weight to obtain thickener;

[0031] (2) Then add the base oil and thickener into the reactor, stir thoroughly and heat to 160~190℃, refine for 2~3 hours, cool to 65~75℃, add the remaining raw materials, stir for 20~40 minutes, cool, grind and homogenize to obtain high temperature resistant and antioxidant lubricating grease.

[0032] The application of the high-temperature resistant and antioxidant grease in bearings as described above.

[0033] The present invention has the following beneficial effects:

[0034] This invention utilizes urea-modified carbon nitride nanosheets to impart excellent thermal stability and improve their dispersion stability in lubricating greases. By loading Ce-MOF material onto the GO surface, the anti-wear performance and load-bearing capacity of the grease are enhanced. Simultaneously, the Ce-MOF material adheres to the friction surface, forming a protective film. Through blending with GO, it achieves a synergistic and complementary effect, jointly promoting the improvement of grease performance. The lubricating grease prepared by this invention exhibits high-temperature resistance, lubricity, and oxidation resistance, making it widely applicable and showing promising application prospects. Detailed Implementation

[0035] 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.

[0036] The base oils are PAO6 and PAO40, with a mass ratio of 2:3; the rust inhibitor is dodecenyl succinic acid; the antioxidant is methylene dibutyl dithiocarbamate; and the dispersant is oleamide.

[0037] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0038] Example 1

[0039] A high-temperature resistant and antioxidant lubricating grease, comprising the following components by weight:

[0040] 140 parts base oil;

[0041] Six portions of urea-modified carbon nitride nanosheets;

[0042] Thickener (the thickener is obtained by reacting aniline with toluene-2,4-diisocyanate, wherein the mass ratio of aniline to toluene-2,4-diisocyanate is 1:1) 25 parts;

[0043] Three portions of Ce-MOF / GO composite material;

[0044] 6 parts rust inhibitor;

[0045] Two parts antioxidant;

[0046] 3 parts dispersant.

[0047] The preparation method of urea-modified carbon nitride nanosheets includes the following steps:

[0048] (1) Disperse 10g of carbon nitride nanosheets into 150mL of ethylene glycol, add 25g of urea, continue stirring for 30min, then react with solvent heat at 180℃ for 10h, filter, wash, and vacuum dry at 80℃ to constant weight to obtain amino-modified carbon nitride nanosheets.

[0049] (2) Disperse 10g of the amino-modified carbon nitride nanosheets obtained in step (1) and 50g of dicyclohexylmethane diisocyanate into 150mL of toluene. Stir at room temperature for 16h under nitrogen protection, filter, wash, and obtain product A. Then disperse 10g of product A into 150mL of toluene, add 4g of aniline, and stir at 40℃ for 14h under nitrogen protection. Filter, wash, and dry under vacuum at 80℃ to constant weight to obtain urea-modified carbon nitride nanosheets.

[0050] The preparation method of Ce-MOF / GO composite material includes the following steps:

[0051] 1 g of graphene oxide and 4 mmol of cerium nitrate were dispersed in 100 mL of ethanol-water, with a volume ratio of ethanol to water of 4:1. The mixture was stirred for 30 min, then 7 mmol of 2-aminoterephthalic acid was added, and the mixture was stirred for 20 min. The mixture was then hydrothermally reacted at 140 °C for 10 h, filtered, washed, and vacuum dried at 80 °C to constant weight to obtain the Ce-MOF / GO composite material.

[0052] The preparation method of the high-temperature resistant and antioxidant lubricating grease specifically includes the following steps:

[0053] (1) Dissolve aniline in ethanol, then add toluene-2,4-diisocyanate, stir evenly, react at 3000 rpm and 60°C for 40 min, filter, and vacuum dry at 70°C to constant weight to obtain thickener;

[0054] (2) Then add the base oil and thickener into the reactor, stir thoroughly and heat to 180°C, refine for 2.5 hours, cool to 70°C, add the remaining raw materials, stir for 30 minutes, cool, grind and homogenize to obtain high temperature resistant and antioxidant lubricating grease.

[0055] Example 2

[0056] A high-temperature resistant and antioxidant lubricating grease, comprising the following components by weight:

[0057] 160 parts base oil;

[0058] Five parts of urea-modified carbon nitride nanosheets;

[0059] Thickener (the thickener is obtained by reacting aniline with toluene-2,4-diisocyanate, wherein the mass ratio of aniline to toluene-2,4-diisocyanate is 1.5:1) 30 parts;

[0060] Two portions of Ce-MOF / GO composite material;

[0061] 7 parts rust inhibitor;

[0062] 1 part antioxidant;

[0063] 4 parts dispersant.

[0064] The preparation method of urea-modified carbon nitride nanosheets includes the following steps:

[0065] (1) Disperse 10g of carbon nitride nanosheets into 150mL of ethylene glycol, add 30g of urea, continue stirring for 40min, then react with solvent heat at 200℃ for 8h, filter, wash, and vacuum dry at 90℃ to constant weight to obtain amino-modified carbon nitride nanosheets.

[0066] (2) Disperse 10g of the amino-modified carbon nitride nanosheets obtained in step (1) and 70g of dicyclohexylmethane diisocyanate into 150mL of toluene. Stir at room temperature for 20h under nitrogen protection, filter, wash, and obtain product A. Then disperse 10g of product A into 150mL of toluene, add 6g of aniline, and stir at 50℃ for 10h under nitrogen protection. Filter, wash, and dry under vacuum at 90℃ to constant weight to obtain urea-modified carbon nitride nanosheets.

[0067] The preparation method of Ce-MOF / GO composite material includes the following steps:

[0068] 1 g of graphene oxide and 5 mmol of cerium acetate were dispersed in 100 mL of ethanol-water, with a volume ratio of ethanol to water of 4:1. The mixture was stirred for 40 min, then 9 mmol of 2-aminoterephthalic acid was added, and the mixture was stirred for 30 min. The mixture was then hydrothermally reacted at 150 °C for 6 h, filtered, washed, and vacuum dried at 90 °C to constant weight to obtain the Ce-MOF / GO composite material.

[0069] The preparation method of the high-temperature resistant and antioxidant grease is the same as that in Example 1.

[0070] Example 3

[0071] A high-temperature resistant and antioxidant lubricating grease, comprising the following components by weight:

[0072] 120 parts base oil;

[0073] Seven portions of urea-modified carbon nitride nanosheets;

[0074] Thickener (the thickener is obtained by reacting aniline with toluene-2,4-diisocyanate, wherein the mass ratio of aniline to toluene-2,4-diisocyanate is 0.5:1) 20 parts;

[0075] Four portions of Ce-MOF / GO composite material;

[0076] 5 parts rust inhibitor;

[0077] Antioxidant 3 parts;

[0078] Two parts of dispersant.

[0079] The preparation method of urea-modified carbon nitride nanosheets includes the following steps:

[0080] (1) Disperse 10g of carbon nitride nanosheets into 150mL of ethylene glycol, add 20g of urea, continue stirring for 20min, and then react with solvent heat at 140℃ for 12h. Filter, wash, and vacuum dry at 60℃ to constant weight to obtain amino-modified carbon nitride nanosheets.

[0081] (2) Disperse 10g of the amino-modified carbon nitride nanosheets obtained in step (1) and 30g of dicyclohexylmethane diisocyanate into 150mL of toluene. Stir at room temperature for 10h under nitrogen protection, filter, wash, and obtain product A. Then disperse 10g of product A into 150mL of toluene, add 2g of aniline, and stir at 30℃ for 18h under nitrogen protection. Filter, wash, and dry under vacuum at 60℃ to constant weight to obtain urea-modified carbon nitride nanosheets.

[0082] The preparation method of Ce-MOF / GO composite material includes the following steps:

[0083] 1 g of graphene oxide and 3 mmol of cerium chloride were dispersed in 100 mL of ethanol-water, with a volume ratio of ethanol to water of 4:1. The mixture was stirred for 20 min, and then 5 mmol of 2-aminoterephthalic acid was added. The mixture was stirred for 10-30 min, and then hydrothermally reacted at 130 °C for 14 h. The mixture was filtered, washed, and vacuum dried at 60 °C to constant weight to obtain the Ce-MOF / GO composite material.

[0084] The preparation method of the high-temperature resistant and antioxidant grease is the same as that in Example 1.

[0085] Comparative Example 1

[0086] The difference between Comparative Example 1 and Example 1 is that boron nitride nanosheets are used instead of carbon nitride nanosheets.

[0087] Comparative Example 2

[0088] The difference between Comparative Example 2 and Example 1 is that an equal amount of amino-modified carbon nitride nanosheets are used instead of urea-modified carbon nitride nanosheets.

[0089] The preparation method of the aminated carbon nitride nanosheets includes the following steps:

[0090] 10g of carbon nitride nanosheets were dispersed in 150mL of ethylene glycol, 30g of urea was added, and the mixture was stirred for 40min. Then, the mixture was solvothermal reacted at 200℃ for 8h, filtered, washed, and vacuum dried at 90℃ to constant weight to obtain amino-modified carbon nitride nanosheets.

[0091] Comparative Example 3

[0092] The difference between Comparative Example 3 and Example 1 is that an equal amount of GO was used to replace the Ce-MOF / GO composite material.

[0093] Comparative Example 4

[0094] The difference between Comparative Example 4 and Example 1 is that an equal amount of urea-modified carbon nitride nanosheets were used to replace the Ce-MOF / GO composite material.

[0095] The performance of the greases in Examples 1-3 and Comparative Examples 1-4 was tested for dropping point according to GB / T 4929-1985. In addition, the PD value of the greases was tested by a four-ball test (120℃). The specific test results are shown in Table 1 below.

[0096] Table 1:

[0097] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Dropping point / ℃ 366 362 363 357 346 349 334 PD value / kgf 455 450 453 445 433 435 421

[0098] As shown in Table 1, the high-temperature grease prepared by this invention has a dropping point above 360℃ and exhibits excellent lubrication performance and good stability at high temperatures. Furthermore, the addition of an antioxidant enhances the grease's antioxidant properties. Therefore, the grease prepared by this invention possesses high-temperature resistance, lubricity, and antioxidant properties, making it widely applicable and promising for future applications.

[0099] 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 high-temperature resistant and antioxidant lubricating grease, characterized in that: By weight, it includes the following components: 120-160 parts base oil; 5-7 parts of urea-modified carbon nitride nanosheets; Thickener 20-30 parts; 2-4 parts of Ce-MOF / GO composite material; 5-7 parts rust inhibitor; Antioxidant 1-3 parts; Dispersant 2-4 parts.

2. The high-temperature resistant and antioxidant lubricating grease according to claim 1, characterized in that: The base is PAO6 and PAO40, with a mass ratio of 2:3; the thickener is obtained by reacting aniline with toluene-2,4-diisocyanate, with a mass ratio of aniline to toluene-2,4-diisocyanate of 0.5~1.5:

1.

3. The high-temperature resistant and antioxidant lubricating grease according to claim 1 or 2, characterized in that: The preparation method of the urea-modified carbon nitride nanosheets includes the following steps: (1) Disperse carbon nitride nanosheets in ethylene glycol, add urea, continue stirring, then carry out a solvothermal reaction, filter, wash, and vacuum dry to constant weight to obtain amino-modified carbon nitride nanosheets. (2) The amino-modified carbon nitride nanosheets and dicyclohexylmethane diisocyanate obtained in step (1) are dispersed in toluene, stirred at room temperature under nitrogen protection, filtered, washed, and then product A is obtained. Then product A is dispersed in toluene, and then aniline is added. Then the reaction is stirred under nitrogen protection, filtered, washed, and vacuum dried to constant weight to obtain urea-modified carbon nitride nanosheets.

4. The high-temperature resistant and antioxidant lubricating grease according to claim 3, characterized in that: In step (1), the mass ratio of urea to carbon nitride nanosheets is 2~3:1; the stirring time is 20~40 min; the solvothermal reaction conditions are 8~12 h at 140~200℃; and the vacuum drying temperature is 60~90℃.

5. The high-temperature resistant and antioxidant lubricating grease according to claim 3, characterized in that: In step (2), the mass ratio of the aminated carbon nitride nanosheets to dicyclohexylmethane diisocyanate is 1:3~7; the mass ratio of product A to aniline is 1:0.2~0.

6.

6. The high-temperature resistant and antioxidant lubricating grease according to claim 3, characterized in that: In step (2), the room temperature stirring time is 10~20h, the stirring reaction conditions are stirring reaction at 30~50℃ for 10~18h, and the drying temperature is 60~90℃.

7. The high-temperature resistant and antioxidant lubricating grease according to claim 1 or 2, characterized in that: The preparation method of the Ce-MOF / GO composite material includes the following steps: Graphene oxide and cerium salt were dispersed in ethanol and water and stirred for 20-40 min. Then 2-aminoterephthalic acid was added and stirred for 10-30 min. The mixture was then hydrothermally reacted at 130-150 °C for 6-14 h. After filtration and washing, the mixture was vacuum dried at 60-90 °C to constant weight to obtain Ce-MOF / GO composite material.

8. The high-temperature resistant and antioxidant lubricating grease according to claim 7, characterized in that: The volume ratio of ethanol to water is 4:1; the ratio of graphene oxide, cerium salt, and 2-aminoterephthalic acid is 1g:3~5mmol:5~9mmol, and the cerium salt is one of cerium nitrate, cerium acetate, and cerium chloride.

9. A method for preparing a high-temperature resistant and antioxidant lubricating grease according to any one of claims 1-8, characterized in that: The preparation method specifically includes the following steps: (1) Dissolve aniline in ethanol, then add toluene-2,4-diisocyanate, stir evenly, react at 2000 rpm to 4000 rpm and 50 to 70 °C for 20 to 60 min, filter, and vacuum dry at 60 to 80 °C to constant weight to obtain thickener; (2) Then add the base oil and thickener into the reactor, stir thoroughly and heat to 160~190℃, refine for 2~3 hours, cool to 65~75℃, add the remaining raw materials, stir for 20~40 minutes, cool, grind and homogenize to obtain high temperature resistant and antioxidant lubricating grease.

10. The application of a high-temperature resistant and antioxidant grease according to any one of claims 1-8 in bearings.