Conductive lubricating grease and preparation method thereof

Abstract

The invention discloses conductive lubricating grease and a preparation method thereof, and belongs to the technical field of lubricating grease materials, the conductive lubricating grease comprises the following components by mass: 50-80 parts of base oil, 5-15 parts of a thickening agent, 3-10 parts of an additive, 5-20 parts of an oil soluble ionic liquid, and 1-10 parts of nanoscale conductive solid particles; the oil-soluble ionic liquid is prepared from trioctylamine, bromohexadecane and sodium di-tert-butyl phosphate. According to the conductive lubricating grease provided by the invention, the oil-soluble ionic liquid and the nanoscale conductive solid particles synergistically conduct electricity, so that the conductive lubricating grease has a tunnel conductive effect and excellent conductivity; besides, due to synergistic conduction of the oil-soluble ionic liquid and the nanoscale conductive solid particles, the addition amount of the conductive solid particles can be reduced, the anti-attrition effect of the conductive lubricating grease is further improved, meanwhile, the nanoscale conductive solid particles have a good anti-attrition effect, the solid size and the oil film thickness are both in nanoscale sizes, and the conductive lubricating grease has a good anti-attrition effect. Therefore, the conductive lubricating grease is excellent in overall anti-wear effect.

Description

Technical Field

[0001] This invention relates to the field of lubricating grease materials technology, specifically a conductive lubricating grease and its preparation method. Background Technology

[0002] Electrical contact is widely present in fields such as power, electronics, aviation, aerospace, and transportation. The quality of electrical contact performance determines the reliability and service life of the entire system. Due to factors such as fretting or sliding, electrical contact typically needs to transfer electrical energy or signals when relative displacement occurs at the contact interface. Therefore, electrical contact is required to have good tribological properties and conductivity.

[0003] Currently, most existing conductive greases use conductive powder materials (such as silver powder, zinc powder, copper powder, and other metal powders) to improve the conductivity of the grease. However, metal powders can reduce the friction-reducing properties of the grease, and the stability of this system is also poor.

[0004] Therefore, developing a conductive grease that can simultaneously achieve stable conductivity and excellent anti-wear properties has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a conductive grease to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a conductive grease comprising the following components by weight: 50-80 parts base oil, 5-15 parts thickener, 3-10 parts additives, 5-20 parts oil-soluble ionic liquid, and 1-10 parts nano-sized conductive solid particles; wherein the oil-soluble ionic liquid is made of trioctylamine, hexadecane bromide, and sodium ditert-butyl phosphate.

[0007] Furthermore, the base oil is a polyalphaolefin base oil with a viscosity of 80-150 mmHg at 40°C. 2 / s.

[0008] Furthermore, the thickener is a polyurea thickener, which is prepared by reacting organic amines with diisocyanates.

[0009] Furthermore, the organic amines include cyclohexylamine and octadecylamine.

[0010] Furthermore, the diisocyanate is diphenylmethane diisocyanate.

[0011] Furthermore, the additives include one or more of extreme pressure anti-wear agents, rust inhibitors, and antioxidants.

[0012] Furthermore, the preparation method of the oil-soluble ionic liquid includes the following steps:

[0013] Trioctylamine and hexadecane bromide were added to a first organic solvent to react. After the reaction was completed, the first organic solvent was removed by vacuum distillation to obtain the intermediate product.

[0014] The intermediate product was dissolved in a second organic solvent, and sodium ditert-butyl phosphate was added for reflux reaction. After the reaction was completed, the second organic solvent was removed by vacuum distillation. The residue was added to a third organic solvent and allowed to stand. The solid was then filtered off, and the filtrate was collected. The third organic solvent was removed by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0015] The crude ionic liquid product was washed and purified to obtain an oil-soluble ionic liquid.

[0016] Furthermore, the first organic solvent is acetonitrile; the second organic solvent is ethanol; and the third organic solvent is n-hexane.

[0017] Furthermore, the nanoscale conductive solid particles are one or more of carbon nanotubes, nanographene, nanozinc oxide, nanomagnesium oxide, nanoniobium diselenide, and nanotitanium dioxide.

[0018] Another object of the present invention is to provide a method for preparing the above-mentioned conductive grease, which includes the following steps:

[0019] The base oil is mixed with the thickener and then heated to 190-210℃ for refining to obtain a semi-finished product;

[0020] Additives, nano-sized conductive solid particles, and oil-soluble ionic liquids are added to the semi-finished product and mixed. Then, the mixture is ground to obtain conductive grease.

[0021] The conductive grease provided by this invention utilizes the synergistic conduction of oil-soluble ionic liquid and nanoscale conductive solid particles, exhibiting a tunneling conductivity effect. Physical modification increases the specific surface area of ​​the solid conductive particles, while modification with the oil-soluble ionic liquid significantly reduces volume resistivity, thereby improving the grease's conductivity. During electron transfer, the synergistic effect of the oil-soluble ionic liquid and nanoscale conductive solid particles greatly enhances the conductivity of the grease. Specifically, the directional movement of positive and negative ions in the oil-soluble ionic liquid synergistically promotes the directional flow of electrons, thus improving the grease's conductivity. Furthermore, the conductive grease provided by this invention exhibits excellent extreme pressure anti-wear performance. Due to the synergistic conduction of the oil-soluble ionic liquid and nanoscale conductive solid particles, the amount of conductive solid particles added can be reduced, thereby improving the anti-wear effect of the conductive grease. Simultaneously, the nanoscale conductive solid particles possess excellent anti-wear properties, with both solid size and oil film thickness at the nanoscale, resulting in superior overall anti-wear performance of the conductive grease. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] In one embodiment of the present invention, a conductive grease is provided, comprising the following components by weight: 50-80 parts base oil, 5-15 parts thickener, 3-10 parts additives, 5-20 parts oil-soluble ionic liquid, and 1-10 parts nano-sized conductive solid particles; wherein the oil-soluble ionic liquid is made of trioctylamine, hexadecane bromide, and sodium ditert-butyl phosphate.

[0024] In a preferred embodiment of the present invention, the conductive grease comprises the following components by weight: 70-75 parts base oil, 8-12 parts thickener, 4-6 parts additives, 6-10 parts oil-soluble ionic liquid, and 5-9 parts nano-sized conductive solid particles.

[0025] In a preferred embodiment of the present invention, the base oil is a polyalphaolefin base oil with a viscosity of 80-150 mmHg at 40°C. 2 / s. The thickener is a polyurea thickener, prepared by reacting organic amines with diisocyanates, specifically including diphenylmethane diisocyanate, cyclohexylamine, and octadecylamine. The additives include one or more of extreme pressure anti-wear agents, rust inhibitors, and antioxidants. The extreme pressure anti-wear agent can be an existing phosphorus-based extreme pressure anti-wear agent such as tricresyl phosphate or triphenyl phosphate, or an existing borate-based extreme pressure anti-wear agent such as sodium metaborate, potassium metaborate, or potassium triborate, but is not limited to these. The rust inhibitor can be an existing barium dinonylnaphthalenesulfonate or barium petroleum sulfonate, but is not limited to these. The antioxidant can be an existing amine antioxidant such as N-phenyl-α-naphthylamine or 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, or an existing phenolic antioxidant such as 2,6-di-tert-butyl-p-cresol or pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (i.e., antioxidant 1010), but is not limited to these.

[0026] In a preferred embodiment of the present invention, the method for preparing an oil-soluble ionic liquid includes the following steps:

[0027] Trioctylamine and hexadecane bromide were added to a first organic solvent to react. After the reaction was completed, the first organic solvent was removed by vacuum distillation to obtain the intermediate product.

[0028] The intermediate product was dissolved in a second organic solvent, and sodium ditert-butyl phosphate was added for reflux reaction. After the reaction was completed, the second organic solvent was removed by vacuum distillation. The residue was added to a third organic solvent and allowed to stand. The solid was then filtered off, and the filtrate was collected. The third organic solvent was removed by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0029] The crude ionic liquid product is washed and purified. Specifically, the crude ionic liquid product is dissolved in a fourth organic solvent and then deionized water is added. The product is washed 2-4 times until the aqueous phase is transparent. The organic phase is then dried with anhydrous magnesium sulfate and the fourth organic solvent is removed by vacuum distillation to obtain the oil-soluble ionic liquid.

[0030] Preferably, the first organic solvent is acetonitrile; the second organic solvent is ethanol; the third organic solvent is n-hexane; and the fourth organic solvent is dichloromethane.

[0031] In a preferred embodiment of the present invention, the nanoscale conductive solid particles are one or more of carbon nanotubes, nanographene, nanozinc oxide, nanomagnesium oxide, nanoniobium diselenide, and nanotitanium dioxide, and their particle size is preferably 10-100 nm.

[0032] In another embodiment of the present invention, a method for preparing the above-mentioned conductive grease is also provided, which includes the following steps: mixing base oil with thickener and heating to 190-210°C for refining to obtain a semi-finished product; adding additives, nano-sized conductive solid particles and oil-soluble ionic liquid to the semi-finished product for mixing, and then grinding to obtain conductive grease.

[0033] Specifically, using polyurea as a thickener, the preparation method of the above-mentioned conductive grease includes the following steps:

[0034] S1. According to the mass percentage, add 35-50 parts of base oil to a clean container, then add 1.2-3.8 parts of octadecylamine, heat to 60-80℃ to completely dissolve it, then add 1.4-4.1 parts of cyclohexylamine to obtain an organic amine mixture; in another container, add 10-20 parts of base oil, then add 2.4-7.1 parts of diisocyanate, heat to 50-60℃ to completely dissolve it to obtain a diisocyanate mixture;

[0035] S2. Slowly add the diisocyanate mixture to the organic amine mixture, heat to 80-100℃ and react for 1-2 hours. After the reaction is complete, add an appropriate amount of water to remove excess diisocyanate, and then heat to 120-130℃ for dehydration for 0.5-1 hour.

[0036] S3. Continue heating to 190-210℃ for high-temperature refining, then add 5-10 parts of base oil and rapidly cool down to obtain a semi-finished product.

[0037] S4. Continue stirring the semi-finished product and cooling it to 90-110℃. Then add 2-4 parts of extreme pressure anti-wear agent, 0.5-1.5 parts of rust inhibitor, 0.5-1.5 parts of antioxidant, 1-10 parts of nano-sized conductive solid particles, and 5-20 parts of oil-soluble ionic liquid. Continue stirring and cooling to 30-50℃. After grinding, the finished conductive grease can be obtained.

[0038] Example 1: This example provides a conductive grease, the preparation method of which specifically includes the following steps:

[0039] S1. Add 45g of base oil to a clean container, then add 2.1g of octadecylamine, heat to 70℃ to completely dissolve it, and then add 2.3g of cyclohexylamine to obtain an organic amine mixture; in another container, add 20g of base oil, then add 4g of diisocyanate, heat to 55℃ to completely dissolve it to obtain a diisocyanate mixture; wherein the base oil is a polyalphaolefin base oil with a viscosity of 100 mmHg at 40℃. 2 / s; the diisocyanate is diphenylmethane diisocyanate;

[0040] S2. Slowly add the above diisocyanate mixture to the organic amine mixture, heat to 90°C and react for 1.5 hours. After the reaction is complete, add 1 wt% water to remove excess diisocyanate, and then heat to 125°C for dehydration for 0.8 hours.

[0041] S3. Continue heating to 200℃ for high-temperature refining, then add 10g of base oil and rapidly cool down to obtain a semi-finished product;

[0042] S4. Continue stirring the semi-finished product and cooling it to 100℃. Then add 3g of tricresyl phosphate, 1g of barium dinonylnaphthalenesulfonate, 1g of 2,6-di-tert-butyl-p-cresol, 4g of nano-graphene, 1.6g of nano-magnesium oxide, and 6g of oil-soluble ionic liquid. Continue stirring and cooling to 40℃. Then grind the mixture to obtain the finished conductive grease.

[0043] The preparation method of oil-soluble ionic liquids includes the following steps:

[0044] S41. Add 0.1 mol of trioctylamine and 0.1 mol of hexadecane bromide to a 250 mL three-necked flask, and add 150 mL of acetonitrile as a solvent. The reaction system is refluxed under nitrogen protection with magnetic stirring for 72 h. After the reaction is completed, the acetonitrile solvent is removed by vacuum distillation to obtain the intermediate product.

[0045] S42. Continue to add ethanol to the three-necked flask to dissolve the intermediate product, and at the same time add 0.1 mol of sodium ditert-butyl phosphate and reflux for 24 h. After the reaction is completed, remove the ethanol solvent by vacuum distillation. Add a large amount of n-hexane to the residue and let it stand for 12 h. Then filter off the white solid, collect the filtrate, and remove the n-hexane solvent by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0046] S43. The crude ionic liquid product is washed and purified. Specifically, the crude ionic liquid product is dissolved in dichloromethane and then deionized water is added. The product is washed three times until the aqueous phase is transparent. The organic phase is then dried with anhydrous magnesium sulfate and the dichloromethane solvent is removed by vacuum distillation to obtain the oil-soluble ionic liquid.

[0047] Example 2: This example provides a conductive grease, the preparation method of which specifically includes the following steps:

[0048] S1. Add 45g of base oil to a clean container, then add 2.1g of octadecylamine, heat to 70℃ to completely dissolve, then add 2.3g of cyclohexylamine to obtain an organic amine mixture; in another container, add 15g of base oil, then add 4g of diisocyanate, heat to 55℃ to completely dissolve, to obtain a diisocyanate mixture; wherein the base oil is a polyalphaolefin base oil with a viscosity of 100 mmHg at 40℃. 2 / s; the diisocyanate is diphenylmethane diisocyanate;

[0049] S2. Slowly add the above diisocyanate mixture to the organic amine mixture, heat to 90°C and react for 1.5 hours. After the reaction is complete, add 1 wt% water to remove excess diisocyanate, and then heat to 125°C for dehydration for 0.8 hours.

[0050] S3. Continue heating to 200℃ for high-temperature refining, then add 10g of base oil and rapidly cool down to obtain a semi-finished product;

[0051] S4. Continue stirring the semi-finished product and cooling it to 100℃. Then add 3g of tricresyl phosphate, 1g of barium dinonylnaphthalenesulfonate, 1g of 2,6-di-tert-butyl-p-cresol, 5g of nano-grade zinc oxide, 2.6g of nano-grade niobium diselenide, and 9g of oil-soluble ionic liquid. Continue stirring and cooling it to 40℃. Then grind it to obtain the finished conductive grease.

[0052] The preparation method of oil-soluble ionic liquids includes the following steps:

[0053] S41. Add 0.1 mol of trioctylamine and 0.1 mol of hexadecane bromide to a 250 mL three-necked flask, and add 150 mL of acetonitrile as a solvent. The reaction system is refluxed under nitrogen protection with magnetic stirring for 72 h. After the reaction is completed, the acetonitrile solvent is removed by vacuum distillation to obtain the intermediate product.

[0054] S42. Continue to add ethanol to the three-necked flask to dissolve the intermediate product, and at the same time add 0.1 mol of sodium ditert-butyl phosphate and reflux for 24 h. After the reaction is completed, remove the ethanol solvent by vacuum distillation. Add a large amount of n-hexane to the residue and let it stand for 12 h. Then filter off the white solid, collect the filtrate, and remove the n-hexane solvent by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0055] S43. The crude ionic liquid product is washed and purified. Specifically, the crude ionic liquid product is dissolved in dichloromethane and then deionized water is added. The product is washed three times until the aqueous phase is transparent. The organic phase is then dried with anhydrous magnesium sulfate and the dichloromethane solvent is removed by vacuum distillation to obtain the oil-soluble ionic liquid.

[0056] Example 3: This example provides a conductive grease, the preparation method of which specifically includes the following steps:

[0057] S1. Add 45g of base oil to a clean container, then add 2.63g of octadecylamine, heat to 70℃ to completely dissolve it, then add 2.88g of cyclohexylamine to obtain an organic amine mixture; in another container, add 15g of base oil, then add 5g of diisocyanate, heat to 55℃ to completely dissolve it to obtain a diisocyanate mixture; wherein the base oil is a polyalphaolefin base oil with a viscosity of 100 mmHg at 40℃. 2 / s; the diisocyanate is diphenylmethane diisocyanate;

[0058] S2. Slowly add the above diisocyanate mixture to the organic amine mixture, heat to 90°C and react for 1.5 hours. After the reaction is complete, add 1 wt% water to remove excess diisocyanate, and then heat to 125°C for dehydration for 0.8 hours.

[0059] S3. Continue heating to 200℃ for high-temperature refining, then add 10g of base oil and rapidly cool down to obtain a semi-finished product;

[0060] S4. Continue stirring the semi-finished product and cooling it to 100℃. Then add 3g of tricresyl phosphate, 1g of barium dinonylnaphthalenesulfonate, 1g of 2,6-di-tert-butyl-p-cresol, 6g of nano-graphene, 2.49g of nano-titanium dioxide, and 6g of oil-soluble ionic liquid. Continue stirring and cooling to 40℃. Then grind the mixture to obtain the finished conductive grease.

[0061] The preparation method of oil-soluble ionic liquids includes the following steps:

[0062] S41. Add 0.1 mol of trioctylamine and 0.1 mol of hexadecane bromide to a 250 mL three-necked flask, and add 150 mL of acetonitrile as a solvent. The reaction system is refluxed under nitrogen protection with magnetic stirring for 72 h. After the reaction is completed, the acetonitrile solvent is removed by vacuum distillation to obtain the intermediate product.

[0063] S42. Continue to add ethanol to the three-necked flask to dissolve the intermediate product, and at the same time add 0.1 mol of sodium ditert-butyl phosphate and reflux for 24 h. After the reaction is completed, remove the ethanol solvent by vacuum distillation. Add a large amount of n-hexane to the residue and let it stand for 12 h. Then filter off the white solid, collect the filtrate, and remove the n-hexane solvent by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0064] S43. The crude ionic liquid product is washed and purified. Specifically, the crude ionic liquid product is dissolved in dichloromethane and then deionized water is added. The product is washed three times until the aqueous phase is transparent. The organic phase is then dried with anhydrous magnesium sulfate and the dichloromethane solvent is removed by vacuum distillation to obtain the oil-soluble ionic liquid.

[0065] Example 4: This example provides a conductive grease, the preparation method of which specifically includes the following steps:

[0066] S1. Add 35g of base oil to a clean container, then add 1.2g of octadecylamine, heat to 60℃ to completely dissolve, then add 1.4g of cyclohexylamine to obtain an organic amine mixture; in another container, add 10g of base oil, then add 2.4g of diisocyanate, heat to 50℃ to completely dissolve, to obtain a diisocyanate mixture; wherein the base oil is a polyalphaolefin base oil with a viscosity of 80 mmHg at 40℃. 2 / s; the diisocyanate is diphenylmethane diisocyanate;

[0067] S2. Slowly add the above diisocyanate mixture to the organic amine mixture, heat to 80°C and react for 1 hour. After the reaction is complete, add 1 wt% water to remove excess diisocyanate, and then heat to 120°C for dehydration for 0.5 hours.

[0068] S3. Continue heating to 190℃ for high-temperature refining, then add 5g of base oil and rapidly cool down to obtain a semi-finished product;

[0069] S4. Continue stirring the semi-finished product and cooling it to 90°C. Then add 2g of tricresyl phosphate, 0.5g of barium dinonylnaphthalenesulfonate, 0.5g of 2,6-di-tert-butyl-p-cresol, 1g of carbon nanotubes, and 5g of oil-soluble ionic liquid. Continue stirring and cooling it to 30°C. Then grind it to obtain the finished conductive grease.

[0070] The preparation method of oil-soluble ionic liquids includes the following steps:

[0071] S41. Add 0.1 mol of trioctylamine and 0.1 mol of hexadecane bromide to a 250 mL three-necked flask, and add 150 mL of acetonitrile as a solvent. The reaction system is refluxed under nitrogen protection with magnetic stirring for 72 h. After the reaction is completed, the acetonitrile solvent is removed by vacuum distillation to obtain the intermediate product.

[0072] S42. Continue to add ethanol to the three-necked flask to dissolve the intermediate product, and at the same time add 0.1 mol of sodium ditert-butyl phosphate and reflux for 24 h. After the reaction is completed, remove the ethanol solvent by vacuum distillation. Add a large amount of n-hexane to the residue and let it stand for 12 h. Then filter off the white solid, collect the filtrate, and remove the n-hexane solvent by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0073] S43. The crude ionic liquid product is washed and purified. Specifically, the crude ionic liquid product is dissolved in dichloromethane and then deionized water is added. The product is washed three times until the aqueous phase is transparent. The organic phase is then dried with anhydrous magnesium sulfate and the dichloromethane solvent is removed by vacuum distillation to obtain the oil-soluble ionic liquid.

[0074] Example 5: This example provides a conductive grease, the preparation method of which specifically includes the following steps:

[0075] S1. Add 50g of base oil to a clean container, then add 3.8g of octadecylamine, heat to 80℃ to dissolve completely, then add 4.1g of cyclohexylamine to obtain an organic amine mixture; in another container, add 20g of base oil, then add 7.1g of diisocyanate, heat to 60℃ to dissolve completely to obtain a diisocyanate mixture; wherein the base oil is a polyalphaolefin base oil with a viscosity of 150 mmHg at 40℃. 2 / s; the diisocyanate is diphenylmethane diisocyanate;

[0076] S2. Slowly add the above diisocyanate mixture to the organic amine mixture, heat to 100°C and react for 2 hours. After the reaction is complete, add 1 wt% water to remove excess diisocyanate, and then heat to 130°C for dehydration for 1 hour.

[0077] S3. Continue heating to 210℃ for high-temperature refining, then add 10g of base oil and rapidly cool down to obtain a semi-finished product;

[0078] S4. Continue stirring the semi-finished product and cooling it to 110℃. Then add 4g of tricresyl phosphate, 1.5g of barium dinonylnaphthalenesulfonate, 1.5g of 2,6-di-tert-butyl-p-cresol, 3g of nano-graphene, 3g of nano-niobium diselenide, 4g of nano-titanium dioxide, and 20g of oil-soluble ionic liquid. Continue stirring and cooling to 50℃. Then grind the mixture to obtain the finished conductive grease.

[0079] The preparation method of oil-soluble ionic liquids includes the following steps:

[0080] S41. Add 0.1 mol of trioctylamine and 0.1 mol of hexadecane bromide to a 250 mL three-necked flask, and add 150 mL of acetonitrile as a solvent. The reaction system is refluxed under nitrogen protection with magnetic stirring for 72 h. After the reaction is completed, the acetonitrile solvent is removed by vacuum distillation to obtain the intermediate product.

[0081] S42. Continue to add ethanol to the three-necked flask to dissolve the intermediate product, and at the same time add 0.1 mol of sodium ditert-butyl phosphate and reflux for 24 h. After the reaction is completed, remove the ethanol solvent by vacuum distillation. Add a large amount of n-hexane to the residue and let it stand for 12 h. Then filter off the white solid, collect the filtrate, and remove the n-hexane solvent by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0082] S43. The crude ionic liquid product is washed and purified. Specifically, the crude ionic liquid product is dissolved in dichloromethane and then deionized water is added. The product is washed three times until the aqueous phase is transparent. The organic phase is then dried with anhydrous magnesium sulfate and the dichloromethane solvent is removed by vacuum distillation to obtain the oil-soluble ionic liquid.

[0083] Example 6: This example provides a conductive grease, the preparation method of which specifically includes the following steps:

[0084] S1. Add 47g of base oil to a clean container, then add 2g of octadecylamine, heat to 70℃ to dissolve completely, then add 2.2g of cyclohexylamine to obtain an organic amine mixture; in another container, add 15g of base oil, then add 3.8g of diisocyanate, heat to 55℃ to dissolve completely to obtain a diisocyanate mixture; wherein the base oil is a polyalphaolefin base oil with a viscosity of 120 mmHg at 40℃. 2 / s; the diisocyanate is diphenylmethane diisocyanate;

[0085] S2. Slowly add the above diisocyanate mixture to the organic amine mixture, heat to 85°C and react for 1 hour. After the reaction is complete, add 1 wt% water to remove excess diisocyanate, and then heat to 125°C for dehydration for 1 hour.

[0086] S3. Continue heating to 195℃ for high-temperature refining, then add 8g of base oil and rapidly cool down to obtain a semi-finished product.

[0087] S4. Continue stirring the semi-finished product and cooling it to 95°C. Then add 2.5g of sodium metaborate, 0.8g of barium petroleum sulfonate, 0.7g of N-phenyl-α-naphthylamine, 6g of carbon nanotubes, 3g of nano-niobium diselenide, and 6g of oil-soluble ionic liquid. Continue stirring and cooling to 30-50°C. After grinding, the finished conductive grease can be obtained.

[0088] The preparation method of oil-soluble ionic liquids includes the following steps:

[0089] S41. Add 0.1 mol of trioctylamine and 0.1 mol of hexadecane bromide to a 250 mL three-necked flask, and add 150 mL of acetonitrile as a solvent. The reaction system is refluxed under nitrogen protection with magnetic stirring for 72 h. After the reaction is completed, the acetonitrile solvent is removed by vacuum distillation to obtain the intermediate product.

[0090] S42. Continue to add ethanol to the three-necked flask to dissolve the intermediate product, and at the same time add 0.1 mol of sodium ditert-butyl phosphate and reflux for 24 h. After the reaction is completed, remove the ethanol solvent by vacuum distillation. Add a large amount of n-hexane to the residue and let it stand for 12 h. Then filter off the white solid, collect the filtrate, and remove the n-hexane solvent by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0091] S43. The crude ionic liquid product is washed and purified. Specifically, the crude ionic liquid product is dissolved in dichloromethane and then deionized water is added. The product is washed three times until the aqueous phase is transparent. The organic phase is then dried with anhydrous magnesium sulfate and the dichloromethane solvent is removed by vacuum distillation to obtain the oil-soluble ionic liquid.

[0092] Example 7: This example provides a conductive grease, the preparation method of which specifically includes the following steps:

[0093] S1. Add 50g of base oil to a clean container, then add 3g of octadecylamine, heat to 75℃ to completely dissolve it, then add 3.3g of cyclohexylamine to obtain an organic amine mixture; in another container, add 15g of base oil, then add 5.7g of diisocyanate, heat to 50℃ to completely dissolve it to obtain a diisocyanate mixture; wherein the base oil is a polyalphaolefin base oil with a viscosity of 100 mmHg at 40℃. 2 / s; the diisocyanate is diphenylmethane diisocyanate;

[0094] S2. Slowly add the above diisocyanate mixture to the organic amine mixture, heat to 90°C and react for 2 hours. After the reaction is complete, add 1 wt% water to remove excess diisocyanate, and then heat to 120°C for dehydration for 1 hour.

[0095] S3. Continue heating to 205℃ for high-temperature refining, then add 8g of base oil and rapidly cool down to obtain a semi-finished product;

[0096] S4. Continue stirring the semi-finished product and cooling it to 105°C. Then add 3.5g of tricresyl phosphate, 1.5g of barium dinonylnaphthalenesulfonate, 1g of 2,6-di-tert-butyl-p-cresol, 3g of carbon nanotubes, 2g of nano titanium dioxide, and 10g of oil-soluble ionic liquid. Continue stirring and cooling to 45°C. Then grind the mixture to obtain the finished conductive grease.

[0097] The preparation method of oil-soluble ionic liquids includes the following steps:

[0098] S41. Add 0.1 mol of trioctylamine and 0.1 mol of hexadecane bromide to a 250 mL three-necked flask, and add 150 mL of acetonitrile as a solvent. The reaction system is refluxed under nitrogen protection with magnetic stirring for 72 h. After the reaction is completed, the acetonitrile solvent is removed by vacuum distillation to obtain the intermediate product.

[0099] S42. Continue to add ethanol to the three-necked flask to dissolve the intermediate product, and at the same time add 0.1 mol of sodium ditert-butyl phosphate and reflux for 24 h. After the reaction is completed, remove the ethanol solvent by vacuum distillation. Add a large amount of n-hexane to the residue and let it stand for 12 h. Then filter off the white solid, collect the filtrate, and remove the n-hexane solvent by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0100] S43. The crude ionic liquid product is washed and purified. Specifically, the crude ionic liquid product is dissolved in dichloromethane and then deionized water is added. The product is washed three times until the aqueous phase is transparent. The organic phase is then dried with anhydrous magnesium sulfate and the dichloromethane solvent is removed by vacuum distillation to obtain the oil-soluble ionic liquid.

[0101] Comparative Example 1: This comparative example provides a commercially available conductive grease, which is a conductive grease containing common metallic copper powder.

[0102] Comparative Example 2: This comparative example provides a conductive grease, which differs from Example 1 in that it does not contain an oil-soluble ionic liquid. The specific preparation method of this conductive grease includes the following steps:

[0103] S1. Add 45g of base oil to a clean container, then add 2.1g of octadecylamine, heat to 70℃ to completely dissolve it, and then add 2.3g of cyclohexylamine to obtain an organic amine mixture; in another container, add 20g of base oil, then add 4g of diisocyanate, heat to 55℃ to completely dissolve it to obtain a diisocyanate mixture; wherein the base oil is a polyalphaolefin base oil with a viscosity of 100 mmHg at 40℃. 2 / s; the diisocyanate is diphenylmethane diisocyanate;

[0104] S2. Slowly add the above diisocyanate mixture to the organic amine mixture, heat to 90°C and react for 1.5 hours. After the reaction is complete, add 1 wt% water to remove excess diisocyanate, and then heat to 125°C for dehydration for 0.8 hours.

[0105] S3. Continue heating to 200℃ for high-temperature refining, then add 10g of base oil and rapidly cool down to obtain a semi-finished product;

[0106] S4. Continue stirring the semi-finished product and cooling it to 100℃. Then add 3g of tricresyl phosphate, 1g of barium dinonylnaphthalenesulfonate, 1g of 2,6-di-tert-butyl-p-cresol, 4g of nano-graphene, and 7.6g of nano-magnesium oxide. Continue stirring and cooling it to 40℃. Then grind it to obtain the finished conductive grease.

[0107] Comparative Example 3: This comparative example provides a conductive grease, which differs from Example 1 in that it does not contain nanoscale conductive solid particles. The specific preparation method of this conductive grease includes the following steps:

[0108] S1. Add 45g of base oil to a clean container, then add 2.1g of octadecylamine, heat to 70℃ to completely dissolve it, and then add 2.3g of cyclohexylamine to obtain an organic amine mixture; in another container, add 20g of base oil, then add 4g of diisocyanate, heat to 55℃ to completely dissolve it to obtain a diisocyanate mixture; wherein the base oil is a polyalphaolefin base oil with a viscosity of 100 mmHg at 40℃. 2 / s; the diisocyanate is diphenylmethane diisocyanate;

[0109] S2. Slowly add the above diisocyanate mixture to the organic amine mixture, heat to 90°C and react for 1.5 hours. After the reaction is complete, add 1 wt% water to remove excess diisocyanate, and then heat to 125°C for dehydration for 0.8 hours.

[0110] S3. Continue heating to 200℃ for high-temperature refining, then add 10g of base oil and rapidly cool down to obtain a semi-finished product;

[0111] S4. Continue stirring the semi-finished product and cooling it to 100℃. Then add 3g of tricresyl phosphate, 1g of barium dinonylnaphthalenesulfonate, 1g of 2,6-di-tert-butyl-p-cresol, and 11.6g of oil-soluble ionic liquid. Continue stirring and cooling to 40℃. Then grind the mixture to obtain the finished conductive grease.

[0112] The preparation method of oil-soluble ionic liquids includes the following steps:

[0113] S41. Add 0.1 mol of trioctylamine and 0.1 mol of hexadecane bromide to a 250 mL three-necked flask, and add 150 mL of acetonitrile as a solvent. The reaction system is refluxed under nitrogen protection with magnetic stirring for 72 h. After the reaction is completed, the acetonitrile solvent is removed by vacuum distillation to obtain the intermediate product.

[0114] S42. Continue to add ethanol to the three-necked flask to dissolve the intermediate product, and at the same time add 0.1 mol of sodium ditert-butyl phosphate and reflux for 24 h. After the reaction is completed, remove the ethanol solvent by vacuum distillation. Add a large amount of n-hexane to the residue and let it stand for 12 h. Then filter off the white solid, collect the filtrate, and remove the n-hexane solvent by vacuum distillation again to obtain the corresponding crude ionic liquid product.

[0115] S43. The crude ionic liquid product is washed and purified. Specifically, the crude ionic liquid product is dissolved in dichloromethane and then deionized water is added. The product is washed three times until the aqueous phase is transparent. The organic phase is then dried with anhydrous magnesium sulfate and the dichloromethane solvent is removed by vacuum distillation to obtain the oil-soluble ionic liquid.

[0116] Performance testing: The conductive greases prepared in Examples 1-3 and Comparative Examples 1-2 were subjected to performance testing, and their structures are shown in Table 1.

[0117] Table 1

[0118]

[0119] As shown in Table 1, the average coefficient of friction of the conductive greases prepared in Comparative Examples 1, 2, and 3 is greater than that of the conductive grease prepared in the embodiments of the present invention. Furthermore, the volume resistivity of the conductive greases prepared in Comparative Examples 1, 2, and 3 is also greater than that of the conductive grease prepared in the embodiments of the present invention. The results indicate that the conductive grease prepared in the embodiments of the present invention exhibits excellent conductivity and friction reduction effect by using oil-soluble ionic liquid and nano-sized conductive solid particles in a synergistic manner. Specifically, the oil-soluble ionic liquid in the embodiments of the present invention, by selecting sodium di-tert-butyl phosphate as a raw material, ensures that the oil-soluble ionic liquid can be stably and uniformly dissolved in the conductive grease without precipitation. Sodium di-tert-butyl phosphate not only serves as a component of the ionic liquid, providing mobile anions to participate in the formation of ionic conductive channels, but also introduces phosphate groups into the conductive grease system, producing a synergistic effect with extreme pressure anti-wear agents and other additives, thereby significantly improving the anti-wear performance of the conductive grease.

[0120] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification.

Claims

1. A conductive lubricating grease, characterized in that, It comprises the following components by weight: 50-80 parts base oil, 5-15 parts thickener, 3-10 parts additives, 5-20 parts oil-soluble ionic liquid, and 1-10 parts nano-sized conductive solid particles; wherein the oil-soluble ionic liquid is made from trioctylamine, hexadecane bromide, and sodium ditert-butyl phosphate.

2. The conductive grease according to claim 1, characterized in that, The base oil is a polyalphaolefin base oil with a viscosity of 80-150 mmHg at 40°C. 2 / s.

3. The conductive grease according to claim 1, characterized in that, The thickener is a polyurea thickener, which is prepared by reacting organic amines with diisocyanates.

4. The conductive grease according to claim 3, characterized in that, The organic amines include cyclohexylamine and octadecylamine.

5. The conductive grease according to claim 3, characterized in that, The diisocyanate is diphenylmethane diisocyanate.

6. The conductive grease according to claim 1, characterized in that, The additives include one or more of extreme pressure anti-wear agents, rust inhibitors, and antioxidants.

7. The conductive grease according to claim 1, characterized in that, The preparation method of the oil-soluble ionic liquid includes the following steps: Trioctylamine and hexadecane bromide were added to a first organic solvent to react. After the reaction was completed, the first organic solvent was removed by vacuum distillation to obtain the intermediate product. The intermediate product was dissolved in a second organic solvent, and sodium ditert-butyl phosphate was added for reflux reaction. After the reaction was completed, the second organic solvent was removed by vacuum distillation. The residue was added to a third organic solvent and allowed to stand. The solid was then filtered off, and the filtrate was collected. The third organic solvent was removed by vacuum distillation again to obtain the corresponding crude ionic liquid product. The crude ionic liquid product was washed and purified to obtain an oil-soluble ionic liquid.

8. The conductive grease according to claim 7, characterized in that, The first organic solvent is acetonitrile; the second organic solvent is ethanol; and the third organic solvent is n-hexane.

9. The conductive grease according to claim 1, characterized in that, The nanoscale conductive solid particles are one or more of the following: carbon nanotubes, nanographene, nanozinc oxide, nanomagnesium oxide, nanoniobium diselenide, and nanotitanium dioxide.

10. A method for preparing a conductive lubricating grease as described in any one of claims 1-9, characterized in that, Includes the following steps: The base oil is mixed with the thickener and then heated to 190-210℃ for refining to obtain a semi-finished product; Additives, nano-sized conductive solid particles, and oil-soluble ionic liquids are added to the semi-finished product and mixed. Then, the mixture is ground to obtain conductive grease.

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