Lubricating grease composition for roller bearing and preparation method thereof

Abstract

The invention relates to the technical field of lubricating grease, and provides a lubricating grease composition for a roller bearing and a preparation method of the lubricating grease composition. The lubricating grease composition for the roller bearing comprises the following components in parts by weight: 80-90 parts of base oil, 10-20 parts of a thickening agent and 1-5 parts of an additive, the additive comprises a filler, and the filler comprises ester compound modified graphene containing amino, hydroxyl and phenyl. According to the technical scheme, the problem that the lubricating grease prepared from graphene is insufficient in lubricity and wear resistance due to the fact that graphene is difficult to disperse in related technologies is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lubricating grease, in particular to a kind of roller bearing grease composition and preparation method thereof. BACKGROUND

[0002] Lubricating grease is a mixture of thickening agent, liquid lubricant and additive, wherein, liquid lubricant, also known as base oil, is the main component of lubricating grease.Compared with lubricating oil, lubricating grease has higher load capacity and better damping capacity, and at room temperature, it can adhere to the vertical surface without loss, and can work in open or poorly sealed friction parts, which has irreplaceable advantages over other lubricants, and is widely used in the lubrication of roller bearings.

[0003] Graphene has good lubricating properties, and with the continuous deepening of scientific research, researchers have found that the addition of graphene to lubricating grease can improve the wear resistance of lubricating grease.However, the difficulty of dispersing graphene has also limited the lubricity and wear resistance of the lubricating grease to some extent. SUMMARY

[0004] The present application provides a kind of roller bearing grease composition and preparation method thereof, which solves the problem of difficult dispersion of graphene in related technology, resulting in insufficient lubricity and wear resistance of the lubricating grease prepared from graphene.

[0005] The technical scheme of the present application is as follows: A kind of roller bearing grease composition, comprising the following components by weight: base oil 80-90 parts, thickening agent 10-20 parts, additive 1-5 parts, the additive includes filler, the filler includes ester compound modified graphene containing amino, hydroxyl and phenyl.

[0006] Base oil is the most abundant component in lubricating grease and is the main substance for lubrication.Both mineral oil and synthetic oil can be used as base oil in the present application.Mineral oil has the advantage of low price, while synthetic oil is used to manufacture high and low temperature or some special purpose lubricating grease.Therefore, the base oil in the present application is preferably synthetic oil, such as poly-alpha-olefin synthetic oil, ester oil, silicone oil, etc.

[0007] The addition of thickening agent can adsorb and fix the base oil in the structural framework.The thickening agent in the present application can be one or more of hydrocarbon-based thickening agent, soap-based thickening agent and inorganic thickening agent.

[0008] As a further technical solution, the raw material of the ester compound modified graphene containing amino, hydroxyl and phenyl includes ester compound containing amino, hydroxyl and phenyl and graphene in a mass ratio of 1-5:100.

[0009] In the present application, the ester compound containing amino, hydroxyl and phenyl can be any one or more ester compounds containing amino, hydroxyl and phenyl, including but not limited to one or more of 3-amino-4-hydroxybenzoic acid methyl ester, levorotatory p-hydroxyphenylglycine methyl ester, 4-amino-3-hydroxybenzoic acid methyl ester, 3-amino-2-hydroxybenzoic acid methyl ester, 2-hydroxy-4-amino benzoic acid methyl ester.

[0010] As a further technical solution, the preparation method of the ester compound containing amino, hydroxyl and phenyl modified graphene includes the following steps: ultrasonic dispersion of graphene in an organic solvent, addition of an ester compound containing amino, hydroxyl and phenyl for modification, drying to obtain an ester compound containing amino, hydroxyl and phenyl modified graphene.

[0011] In the present application, the organic solvent can be any solvent that can dissolve the ester compound containing amino, hydroxyl and phenyl, for example, it can be chloroform, dimethyl sulfoxide, methanol, etc., preferably a low-boiling-point organic solvent, such as chloroform, methanol.

[0012] As a further technical solution, the frequency of the ultrasonic is 50-80 kHz, the power of the ultrasonic is 100-500 W, the temperature of the ultrasonic is 25-35℃, and the time of the ultrasonic is 20-60 min.

[0013] As a further technical solution, the modification process is accompanied by stirring, the stirring speed is 100-150 rpm, and the stirring time is 20-40 min.

[0014] As a further technical solution, the filler further includes silane-modified molybdenum disulfide.

[0015] Compared with graphene, molybdenum disulfide has better friction performance. Therefore, in the present application, silane-modified molybdenum disulfide is further introduced as a filler. After the modification of molybdenum disulfide by silane (such as aminosilane, epoxy silane, vinyl silane, etc.), the surface will have active groups such as amino, epoxy, vinyl, etc., which can interact with the surface groups of the ester compound containing amino, hydroxyl and phenyl modified graphene, and the good dispersibility of the modified graphene can be used to prevent the settling of molybdenum disulfide, thereby further improving the lubricity and wear resistance of the grease.

[0016] As a further technical solution, the silane-modified molybdenum disulfide is epoxy silane-modified molybdenum disulfide, and the mass ratio of the ester compound containing amino, hydroxyl and phenyl modified graphene to the epoxy silane-modified molybdenum disulfide is 3-5:1.

[0017] In the present application, the molybdenum disulfide is modified by epoxy silane, and the mass ratio of the ester compound containing amino, hydroxyl and phenyl modified graphene and the molybdenum disulfide modified by epoxy silane is limited to 3-5:1, so that the lubricity and wear resistance of the grease are further improved.

[0018] As a further technical solution, the additive further comprises at least one of the following features: a stabilizer, an antioxidant, a rust inhibitor.

[0019] In the present application, the additive can be selected from any conventional additive in the art, such as a stabilizer, an antioxidant, a rust inhibitor, a preservative, etc. Preferably, the additive comprises an antioxidant, a rust inhibitor and a filler in a mass ratio of 1:1-2:2-5. The antioxidant can comprise one or more of an amine antioxidant and a phenolic antioxidant, the amine antioxidant can comprise one or more of naphthylamine, diphenylamine, p-phenylenediamine and phenothiazine, and the phenolic antioxidant can comprise one or more of 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole and tea polyphenol. The rust inhibitor can comprise one or more of dodecenyl succinic acid T746, sodium petroleum sulfonate, barium petroleum sulfonate, dodecenyl succinamide, zinc naphthenate, aluminum stearate, benzotriazole and trisodium phosphate.

[0020] The present application also provides a preparation method of the grease composition for roller bearings, which comprises the following steps: heating base oil to 70-90 DEG C, adding a thickening agent and an additive and mixing uniformly, cooling to 30-40 DEG C, and obtaining the grease composition for roller bearings.

[0021] The working principle and beneficial effects of the present application are as follows: The hydroxyl functional group in the ester compound containing amino, hydroxyl and phenyl in the present application can form a hydrogen bond with graphene, and the phenyl group can form a pi-pi stacking effect with graphene, so as to realize the non-covalent surface modification of graphene. By modifying graphene with the ester compound containing amino, hydroxyl and phenyl, the surface properties of graphene are changed, the dispersibility of graphene is improved, and the lubricity and wear resistance of the grease prepared from graphene are improved. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also fall within the scope of protection of the present application.

[0023] The parameters of the raw materials in the following examples and comparative examples are as follows: Graphene: Model SY-GNP-S, purchased from Beijing Meiston Technology Development Co., Ltd. Molybdenum disulfide: 2000 mesh; Polyalphaolefin synthetic oil: PAO10 kinematic viscosity (40℃) 66 mm 2 / s, kinematic viscosity (100℃) 10.1mm 2 / s, viscosity index 137, density (20℃) 0.835kg / m³ 3 .

[0024] Example 1 S1. 100 parts of graphene were ultrasonically dispersed in 200 parts of methanol. The ultrasonic frequency was 50 kHz, the ultrasonic power was 100 W, the ultrasonic temperature was 25 ℃, and the ultrasonic time was 60 min. 1 part of methyl 3-amino-2-hydroxybenzoate was added and stirred at 100 rpm for 40 min for modification. After drying, modified graphene was obtained. S2. Transfer polyalphaolefin synthetic oil from the storage tank to the machine oil tank in the workshop. Then, pump 80 parts of polyalphaolefin synthetic oil from the machine oil tank into the heating kettle through the flow meter and heat it to 70°C. Add 10 parts of dodecyl stearic acid and 1 part of additive (the additive consists of antioxidant 264, rust inhibitor T701 and modified graphene in a mass ratio of 1:1:2). After stirring and mixing for 15 minutes, pump it into the cooling kettle. Stir in the cooling kettle for 39 minutes, then circulate water through the cooling kettle jacket to cool it down. When the temperature drops to 30°C, pump it into the finished product kettle. Then, pack the finished grease into the packaging barrel to obtain the grease composition for roller bearings.

[0025] Example 2 S1. 100 parts of graphene were ultrasonically dispersed in 200 parts of methanol. The ultrasonic frequency was 80kHz, the ultrasonic power was 500W, the ultrasonic temperature was 35℃, and the ultrasonic time was 20min. 5 parts of methyl 3-amino-2-hydroxybenzoate were added and stirred at 150rpm for 20min for modification. The mixture was then dried to obtain modified graphene. S2. Transfer polyalphaolefin synthetic oil from the storage tank into the machine oil tank in the workshop. Then, pump 90 parts of polyalphaolefin synthetic oil from the machine oil tank into the heating kettle through the flow meter and heat it to 90°C. Add 20 parts of dodecyl stearic acid and 5 parts of additives (the additives consist of antioxidant 264, rust inhibitor T701 and modified graphene in a mass ratio of 1:2:5). After stirring and mixing for 15 minutes, pump it into the cooling kettle. Stir in the cooling kettle for 39 minutes, then circulate water through the cooling kettle jacket to cool it down. When the temperature drops to 40°C, pump it into the finished product kettle. Then, pack the finished grease into packaging barrels to obtain the grease composition for roller bearings.

[0026] Example 3 The only difference from Example 2 is that the additive consists of antioxidant 264, rust inhibitor T701 and filler in a mass ratio of 1:2:5, and the filler consists of modified graphene and silane-modified molybdenum disulfide in a mass ratio of 3:1. The preparation method of silane-modified molybdenum disulfide includes the following steps: Add 5 mL of deionized water and 23 mL of anhydrous ethanol to 5 mL of KH550, stir well, seal and let stand for 1 h to obtain silane hydrolysate; add 100 mL of deionized water to 1 g of molybdenum disulfide, sonicate for 30 min, then add 100 mL of ethanol and 5 mL of the above silane hydrolysate, react at 60 °C for 1 h, filter, wash, and dry to obtain silane-modified molybdenum disulfide.

[0027] Example 4 The only difference from Example 3 is that KH550 is replaced with an equal amount of KH560.

[0028] Example 5 The only difference from Example 4 is that the filler consists of modified graphene and silane-modified molybdenum disulfide in a mass ratio of 4:1.

[0029] Example 6 The only difference from Example 4 is that the filler consists of modified graphene and silane-modified molybdenum disulfide in a mass ratio of 5:1.

[0030] Comparative Example 1 Polyalphaolefin synthetic oil is transferred from the storage tank to the machine oil tank in the workshop. Then, 90 parts of the polyalphaolefin synthetic oil are pumped from the machine oil tank into the heating kettle through a flow meter and heated to 90°C. 20 parts of dodecyl stearic acid and 5 parts of additives (the additives consist of antioxidant 264, rust inhibitor T701 and graphene in a mass ratio of 1:2:5) are added and stirred for 15 minutes. The mixture is then pumped into the cooling kettle and stirred for 39 minutes. Water is then circulated through the jacket of the cooling kettle to cool it down. When the temperature drops to 40°C, the mixture is pumped into the finished product kettle. Finally, the finished grease is packaged into packaging barrels to obtain the grease composition for roller bearings.

[0031] Performance testing: Long-term wear tests were conducted using an MMW-1 vertical universal friction and wear testing machine at a temperature of 75℃, a time of 60 min, a load of 392 N, and a rotation speed of 1450 r / min. The coefficient of friction was determined, and the wear scar diameter (WSD) was measured according to Method A in SH / T 0204-1992. The average value of three wear scar diameters was taken as the experimental result. The selected steel ball had a diameter of 12.7 mm, a hardness of HRC 60, and a weight of 2.5 kg. The test results are recorded in Table 1.

[0032] Table 1. Test results of friction coefficient and wear scar diameter

[0033] As shown in Table 1, the grease composition provided by this invention has a coefficient of friction below 1.28 and a wear scar diameter (WSD) below 0.39 mm, exhibiting good lubricity and anti-wear properties. The grease composition obtained in Example 2 has a lower coefficient of friction and wear scar diameter than Comparative Example 1, indicating that modification of graphene with ester compounds containing amino, hydroxyl, and phenyl groups improves the lubricity and anti-wear properties of the grease prepared from graphene.

[0034] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A grease composition for a roller bearing, characterized by, The composition comprises the following components by weight: base oil 80-90 parts, thickening agent 10-20 parts, additive 1-5 parts, the additive comprises a filler, the filler comprises an ester compound modified graphene containing amino, hydroxyl and phenyl.

2. A roll bearing grease composition according to claim 1, characterized in that, The raw material of the ester compound modified graphene containing amino, hydroxyl and phenyl comprises an ester compound containing amino, hydroxyl and phenyl and graphene in a mass ratio of 1-5:

100.

3. The grease composition for a roller bearing according to claim 1, characterized by The preparation method of the ester compound modified graphene containing amino, hydroxyl and phenyl comprises the following steps: ultrasonic dispersion of graphene in an organic solvent, addition of an ester compound containing amino, hydroxyl and phenyl for modification, drying to obtain the ester compound modified graphene containing amino, hydroxyl and phenyl.

4. A roll bearing grease composition according to claim 3, characterised in that The frequency of the ultrasonic is 50-80 kHz, the power of the ultrasonic is 100-500 W, the temperature of the ultrasonic is 25-35℃, and the time of the ultrasonic is 20-60 min.

5. A roll bearing grease composition according to claim 3, wherein The stirring is accompanied in the modification process, the rotating speed of the stirring is 100-150 rpm, and the time of the stirring is 20-40 min.

6. The grease composition for a roller bearing according to claim 1, characterized by The filler further comprises silane modified molybdenum disulfide.

7. A roll bearing grease composition according to claim 6, characterised in that The silane modified molybdenum disulfide is epoxy silane modified molybdenum disulfide, and the mass ratio of the ester compound modified graphene containing amino, hydroxyl and phenyl, epoxy silane modified molybdenum disulfide is 3-5:

1.

8. The grease composition for a roller bearing according to claim 1, characterized by The additive further comprises at least one of the following features: stabilizer, antioxidant, rust inhibitor.

9. The grease composition for a roller bearing according to claim 1, characterized by The additive comprises antioxidant, rust inhibitor and filler in a mass ratio of 1:1-2:2-5.

10. A method for producing a roll bearing grease composition, for producing a roll bearing grease composition according to any one of claims 1 to 9, characterized by, The method comprises the following steps: The base oil is heated to 70-90℃, the thickening agent and the additive are added and uniformly mixed, and then cooled to 30-40℃ to obtain the grease composition for roll bearing. The base oil is heated to 70-90℃, the thickening agent and the additive are added and uniformly mixed, and then cooled to 30-40℃ to obtain the grease composition for roll bearing.

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