Preparation process of environment-friendly degradable corrosion-resistant sealing grease

Abstract

The application provides a preparation process of an environment-friendly degradable corrosion-resistant sealing grease, and belongs to the technical field of sealing grease; a treatment process thereof comprises the following steps: preparing a rust-proof additive; preparing a viscosity adjusting additive; preparing a corrosion-proof additive; and mixing components to prepare the sealing grease.The sealing grease is composed of degradable base oil, fibers and environment-friendly additives, and has the advantages of biodegradability, no odor, environmental protection, non-toxicity and no environmental pollution; wherein, the corrosion-proof additive is prepared by mixing n-bromooctane, n-bromodecane and tri-n-butyl phosphine to react, and then adding a mixed solution of mercapto benzothiazole and potassium hydroxide to continue the reaction; after the corrosion-proof additive is added into the sealing grease, the effect of delaying grease aging and improving the corrosion resistance of the grease can be achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of sealing grease, and particularly relates to a preparation process of environment-friendly degradable corrosion-resistant sealing grease. BACKGROUND

[0002] Sealing grease is a material mainly used in the shield tail part of a shield machine, plays a sealing and lubricating role, is prepared from base oil as a matrix and various additives such as fibers, tackifiers and fillers, and is a uniform paste.

[0003] The traditional sealing grease can provide effective sealing and lubrication, but usually contains ingredients that are difficult to degrade, and causes environmental burden after long-term use. In addition, the existing sealing grease is insufficient in corrosion resistance, and the sealing grease can be oxidized during use, especially under the conditions of contacting acid and alkali medium, salt mist environment or high temperature, and is prone to performance degradation, leading to sealing failure, and further affecting the normal operation and service life of the equipment.

[0004] Therefore, the application provides a preparation process of environment-friendly degradable corrosion-resistant sealing grease, so as to prolong the service life of the sealing grease and reduce environmental pollution. SUMMARY

[0005] In view of the deficiencies of the prior art, the application aims to provide environment-friendly degradable corrosion-resistant sealing grease which not only has excellent sealing performance and corrosion resistance, but also can be quickly degraded in a natural environment, reducing environmental pollution.

[0006] A preparation process of environment-friendly degradable corrosion-resistant sealing grease comprises the following steps:

[0007] S1: preparing a rust-proof additive

[0008] Methyl oleate and maleic anhydride are mixed and heated to react, then distilled under reduced pressure, mixed with distilled water and heated to perform hydrolysis reaction, and then distilled under reduced pressure again to obtain the rust-proof additive;

[0009] S2: preparing a viscosity adjusting additive

[0010] Tannic acid, ethyl acetate, butyl acetate, triphenylphosphine and p-benzenediol monomethyl ether are stirred and mixed, then glycidyl methacrylate and Versatic acid glycidyl ester are added and heated to react, so as to obtain the viscosity adjusting additive;

[0011] S3: preparing a corrosion-proof additive

[0012] The intermediate A is prepared by uniformly mixing n-bromooctane, n-bromodecane and tri-n-butyl phosphine, and the intermediate A is dissolved in methanol to form an intermediate A solution, which is ready for use. Then, mercaptobenzothiazole and potassium hydroxide are dissolved in methanol to form a ternary mixture, which is ready for use. Subsequently, the intermediate A solution is added to the ternary mixture to react, thereby obtaining the corrosion inhibitor;

[0013] S4: mixing the components to prepare the sealing grease

[0014] The base oil, the above-mentioned rust inhibitor, the above-mentioned viscosity adjusting additive and the above-mentioned corrosion inhibitor are added into a kneader, and kneaded for 30-40 min. Then, the lubricating grease is added into the kneader, and continues to be kneaded for 40-50 min. Then, the fibers are added into the kneader, and continues to be kneaded for 20-30 min. Then, the fillers are added into the kneader, and continues to be kneaded for 2-3 h, thereby obtaining the sealing grease.

[0015] Further, S1 specifically comprises the following steps:

[0016] S1.1: the methyl oleate and the maleic anhydride are added into a reactor according to the molar ratio of 1:(1.3-1.8), and stirred and mixed uniformly. Then, the mixture is heated at a temperature of 200-260℃ for 8-10 h to react, and naturally cooled to room temperature to obtain a crude product;

[0017] S1.2: the crude product is placed in a reduced pressure distiller, and the impurities are removed by reduced pressure distillation. After naturally cooling to room temperature, a precursor is obtained.

[0018] S1.3: the precursor and distilled water are stirred and mixed uniformly according to the molar ratio of 1:(3-5), and then heated at a temperature of 60-80℃ for 6-8 h to perform a hydrolysis reaction. Then, the excess distilled water is removed by reduced pressure distillation, thereby obtaining the rust inhibitor.

[0019] Further, S2 specifically comprises the following steps:

[0020] S2.1: the tannic acid, the ethyl acetate and the butyl acetate are added into a reaction tank according to the solid-liquid ratio of (15-20)g:(16-20)mL:(7-9)mL, and heated at a temperature of 80-90℃ while stirring at a speed of 200-300 r / min for 30-40 min to mix sufficiently, thereby obtaining a mixed solution A;

[0021] S2.2: the heating temperature is kept unchanged, and the stirring speed is adjusted to 100-200 r / min. While stirring, the triphenyl phosphine and the hydroquinone monomethyl ether are added into the mixed solution A, and continues to be stirred for 20-30 min, thereby obtaining a mixed solution B.

[0022] S2.3: While maintaining the heating temperature and stirring rate, add glycidyl methacrylate and glycidyl versatic acid to the mixed solution B while stirring. Heat and react for 10-12 hours. Remove the solvent by distillation under reduced pressure to obtain a viscosity regulating additive.

[0023] Furthermore, S3 specifically includes the following steps:

[0024] S3.1: Mix n-octane bromide, n-decane bromide, and tri-n-butylphosphine in a mass ratio of 1:(1.2-1.4):(1-1.2), then heat at 140-150°C under nitrogen for 10-12 hours for reflux reaction. Remove impurities by distillation under reduced pressure to obtain Intermediate A.

[0025] S3.2: Add the intermediate A to methanol at a mass ratio of 1:(60-70), stir thoroughly to dissolve, and obtain an intermediate A solution;

[0026] S3.3: Add mercaptobenzothiazole and potassium hydroxide to methanol at a solid-liquid ratio of (3-5) g:1 g:(20-30) mL and stir thoroughly to dissolve to obtain a ternary mixture.

[0027] S3.4: Add the intermediate A solution to the ternary mixture, and then stir at 400-500 rpm for 2-3 hours to react to obtain a suspension, wherein the molar ratio of mercaptobenzothiazole to intermediate A is 1:(1-1.4);

[0028] S3.5: Place the suspension in a centrifuge and filter it to remove solid impurities. Then, evaporating the filtrate to remove the solvent and water, yielding Intermediate B.

[0029] S3.6: Add the intermediate B mentioned above to anhydrous ethanol, stir thoroughly to dissolve, centrifuge and evaporating, place in a vacuum drying oven, and vacuum dry for 1-2 hours to obtain the anti-corrosion additive.

[0030] Furthermore, the mass ratio of triphenylphosphine to tannic acid is 1:(18-20), and the mass ratio of hydroquinone monomethyl ether to tannic acid is 1:(280-300).

[0031] Furthermore, the mass ratios of glycidyl methacrylate and glycidyl versatic acid to tannic acid are (1.6-2):1 and 1:(1.4-1.8), respectively.

[0032] Furthermore, the sealing grease comprises, by weight: 16-20 parts of base oil, 10-18 parts of viscosity regulating additive, 8-10 parts of anti-corrosion additive, 1-3 parts of anti-rust additive, 12-16 parts of grease, 10-15 parts of fiber and 20-30 parts of filler; wherein the base oil is one or more of vegetable oil, polyol ester, polyester, polyether ester and glycerol.

[0033] Furthermore, the fiber is one or more of cotton fiber, polylactic acid fiber, cellulose fiber, chitin fiber and animal fiber.

[0034] Furthermore, the filler is one or more of calcium carbonate, bentonite, talc and kaolin.

[0035] Furthermore, the lubricating grease is one or more of lithium-based lubricating grease, sulfurized lard, lanolin, molybdenum disulfide lubricating grease, and calcium-based lubricating grease.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] 1. The present invention prepares an anti-corrosion additive by first mixing n-octane bromide, n-decane bromide and tri-n-butylphosphine for reaction, then adding the mixture to a mixed solution of mercaptobenzothiazole and potassium hydroxide for further reaction. After the anti-corrosion additive is added to the sealing grease, on the one hand, the mercapto group can effectively capture the free radicals generated during the oxidation of the sealing grease, interrupting the grease oxidation chain reaction; on the other hand, the anti-corrosion additive can form a stable complex with metal ions, effectively inhibiting the catalytic effect of the metal surface and reducing the oxidation reaction initiated by the metal, thereby achieving the effect of delaying the aging of the grease and improving the corrosion resistance of the grease. In addition, due to the friction between the anti-corrosion additive and the metal, a tribochemical reaction occurs to generate tribochemical products containing the element S, and these products can form a boundary lubricating film together with the oxide on the metal surface, showing a friction-reducing and anti-wear effect, thereby improving the extreme pressure and anti-wear performance of the sealing grease.

[0038] 2. The present invention prepares a viscosity regulating additive by heating and stirring tannic acid, triphenylphosphine, and hydroquinone monomethyl ether, and then adding glycidyl methacrylate and glycidyl versatic acid to react. When the viscosity regulating additive is added to the sealing grease, it forms a three-dimensional cross-linked network in the sealing grease, thereby reducing the relative sliding between grease molecules, increasing intermolecular friction, and enhancing the overall structural strength and viscosity, thereby achieving the effect of improving the cohesiveness and adhesion of the sealing grease and helping to form a more stable sealing layer.

[0039] 3. The present invention prepares an anti-rust additive by mixing methyl oleate and maleic anhydride, heating them to react, and then mixing them with distilled water to undergo a hydrolysis reaction. Since the carboxyl end of the anti-rust additive easily undergoes chemical adsorption with the metal surface to form a dense adsorption film, which prevents air and water from contacting the metal and causing it to rust, the anti-rust additive is added to the sealing grease to effectively improve the anti-rust performance of the sealing grease.

[0040] 4. The sealing grease of the present invention is composed of degradable base oil, fiber and environmentally friendly additives, etc. It is biodegradable, odorless, environmentally friendly and non-toxic, and has no pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable one skilled in the relevant art to make and use the present disclosure.

[0042] Figure 1 This is a flow chart of the preparation process of the environmentally friendly, degradable, and corrosion-resistant sealing grease used in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The preparation process of an environmentally friendly, degradable, and corrosion-resistant sealing grease provided by the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Example 1

[0045] A preparation process of environmentally friendly biodegradable corrosion-resistant sealing grease, such as Figure 1 As shown, the following steps are included:

[0046] S1: Preparation of anti-rust additives

[0047] Methyl oleate and maleic anhydride are added to a reactor at a molar ratio of 1:1.3, stirred and mixed, heated at 200°C for 8 hours to react, and naturally cooled to room temperature to obtain a crude product. Subsequently, the crude product is placed in a vacuum distiller, vacuum distilled to remove impurities, and naturally cooled to room temperature to obtain a precursor. The precursor and distilled water are then stirred and mixed at a molar ratio of 1:3 to obtain a uniform mixture, and then heated at 60°C for 6 hours to carry out a hydrolysis reaction. The excess distilled water is then removed by vacuum distillation to obtain an anti-rust additive.

[0048] S2: Preparation of viscosity-adjusting additives

[0049] Tannic acid, ethyl acetate and butyl acetate were added to a reaction tank at a solid-liquid ratio of 15 g:16 mL:7 mL, heated at 80° C., stirred at a rate of 200 r / min for 30 min, and fully mixed to obtain a mixed solution A. Then, while keeping the heating temperature constant and adjusting the stirring rate to 100 r / min, triphenylphosphine and hydroquinone monomethyl ether were added to the mixed solution A while stirring, and stirring was continued for 20 min to obtain a mixed solution B, wherein the mass ratio of triphenylphosphine to tannic acid was 1:18, and the mass ratio of hydroquinone monomethyl ether to tannic acid was 1:280. Subsequently, while keeping the heating temperature and stirring rate constant, glycidyl methacrylate and Versatic acid glycidyl ester were added to the mixed solution B while stirring, and the mixture was heated for 10 h. The solvent was removed by distillation under reduced pressure to obtain a viscosity regulating additive, wherein the mass ratios of glycidyl methacrylate and Versatic acid glycidyl ester to tannic acid were 1.6:1 and 1:1.4, respectively.

[0050] S3: Preparation of anti-corrosion additives

[0051] n-Bromooctane, n-Bromodecane and tri-n-butylphosphine were stirred and mixed uniformly in a mass ratio of 1:1.2:1, and then heated at 140°C for 10 hours under nitrogen protection for reflux reaction. Impurities were removed by reduced pressure distillation to obtain intermediate A, and then intermediate A was added to methanol in a mass ratio of 1:60, stirred and dissolved to obtain intermediate A solution, which was set aside. Mercaptobenzothiazole and potassium hydroxide were added to methanol in a solid-liquid ratio of 3g:1g:20mL, stirred and dissolved to obtain a ternary mixed solution, which was set aside. Subsequently, intermediate A was added to methanol in a solid-liquid ratio of 3g:1g:20mL, stirred and dissolved to obtain a ternary mixed solution, which was set aside. The intermediate A solution is added to the above ternary mixture, and then stirred at a rate of 400 r / min for 2 hours to react to obtain a suspension, wherein the molar ratio of mercaptobenzothiazole to intermediate A is 1:1, and then the suspension is placed in a centrifuge and centrifuged to remove solid impurities, and then the filtrate is rotary evaporated to remove the solvent and water to obtain intermediate B. Finally, the intermediate B is added to anhydrous ethanol, fully stirred to dissolve, and after centrifugal filtration and rotary evaporation, placed in a vacuum drying oven and vacuum dried for 1 hour to obtain an anticorrosive additive;

[0052] S4: Mix the components to prepare sealing grease

[0053] Add 16 parts of vegetable oil, 1 part of the above-mentioned anti-rust additive, 10 parts of the above-mentioned viscosity regulating additive and 8 parts of the above-mentioned anti-corrosion additive into a kneader and knead for 30 minutes. Then add 12 parts of sulfurized lard into the kneader and continue kneading for 40 minutes. Then, add 10 parts of cotton fiber into the kneader and continue kneading for 20 minutes. Then, add 20 parts of calcium carbonate into the kneader and continue kneading for 2 hours to obtain sealing grease.

[0054] Example 2

[0055] A preparation process of environmentally friendly biodegradable corrosion-resistant sealing grease, such as Figure 1 As shown, the following steps are included:

[0056] S1: Preparation of anti-rust additives

[0057] Methyl oleate and maleic anhydride are added to a reactor in a molar ratio of 1:1.5, stirred and mixed, heated at 230°C for 9 hours to react, and naturally cooled to room temperature to obtain a crude product. Subsequently, the crude product is placed in a vacuum distiller, vacuum distilled to remove impurities, and naturally cooled to room temperature to obtain a precursor. The precursor and distilled water are then stirred and mixed in a molar ratio of 1:4, and then heated at 70°C for 7 hours to carry out a hydrolysis reaction. The excess distilled water is then removed by vacuum distillation to obtain an anti-rust additive.

[0058] S2: Preparation of viscosity-adjusting additives

[0059] Tannic acid, ethyl acetate and butyl acetate were added to a reaction tank at a solid-liquid ratio of 17.5 g:18 mL:8 mL, heated at 85° C., stirred at a rate of 250 r / min for 35 min, and fully mixed to obtain a mixed solution A. Then, while maintaining the heating temperature unchanged and adjusting the stirring rate to 150 r / min, triphenylphosphine and hydroquinone monomethyl ether were added to the mixed solution A while stirring, and stirring was continued for 25 min to obtain a mixed solution B, wherein the mass ratio of triphenylphosphine to tannic acid was 1:19, and the mass ratio of hydroquinone monomethyl ether to tannic acid was 1:290. Subsequently, while maintaining the heating temperature and stirring rate unchanged, glycidyl methacrylate and Versatic acid glycidyl ester were added to the mixed solution B while stirring, and the mixture was heated for 11 h. The solvent was removed by distillation under reduced pressure to obtain a viscosity regulating additive, wherein the mass ratios of glycidyl methacrylate and Versatic acid glycidyl ester to tannic acid were 1.8:1 and 1:1.6, respectively.

[0060] S3: Preparation of anti-corrosion additives

[0061] The n-brominated octane, n-brominated decane and tri-n-butyl phosphine are mixed uniformly in a mass ratio of 1:1.3:1.1, then heated to reflux at a temperature of 145℃ for 11h under nitrogen protection, impurities are removed by reduced pressure distillation, to obtain intermediate A, then intermediate A is added to methanol in a mass ratio of 1:65, fully stirred and dissolved to obtain intermediate A solution, which is used for standby, then mercaptobenzothiazole and potassium hydroxide are added to methanol in a solid-liquid ratio of 4g:1g:25mL, fully stirred and dissolved to obtain a ternary mixture, which is used for standby, then the intermediate A solution is added to the above-mentioned ternary mixture, then stirred at a speed of 450r / min for 2.5h to carry out the reaction, to obtain a suspension, wherein the molar ratio of mercaptobenzothiazole to intermediate A is 1:1.2, then the suspension is placed in a centrifuge for centrifugal filtration to remove solid impurities, then the filtrate is subjected to rotary evaporation to remove the solvent and water, to obtain intermediate B, finally, intermediate B is added to anhydrous ethanol, fully stirred and dissolved, then subjected to centrifugal filtration and rotary evaporation, and then placed in a vacuum drying box for vacuum drying for 1.5h, to obtain a corrosion inhibitor;

[0062] S4: mixing components to prepare sealing grease

[0063] Put 18 parts of polyol ester, 2 parts of the above-mentioned rust inhibitor, 19 parts of the above-mentioned viscosity adjusting additive and 9 parts of the above-mentioned corrosion inhibitor into a kneader, knead for 35min, then put 14 parts of lanolin into the kneader, continue to knead for 45min, then put 12 parts of polylactic acid fiber into the kneader, continue to knead for 25min, then put 25 parts of bentonite into the kneader, continue to knead for 2.5h, to obtain sealing grease.

[0064] Example 3

[0065] A preparation process of an environmentally friendly degradable corrosion-resistant sealing grease, as shown in Figure 1 , comprises the following steps:

[0066] S1: preparing a rust inhibitor

[0067] Put methyl oleate and maleic anhydride into a reactor in a molar ratio of 1:1.8, stir and mix uniformly, then heat to a temperature of 260℃ for 10h to carry out the reaction, and naturally cool to room temperature to obtain a crude product, then put the crude product into a reduced pressure distillation apparatus to remove impurities by reduced pressure distillation, and naturally cool to room temperature to obtain a precursor, then stir and mix uniformly the precursor and distilled water in a molar ratio of 1:5, heat to a temperature of 80℃ for 8h to carry out a hydrolysis reaction, and then remove excess distilled water by reduced pressure distillation, to obtain a rust inhibitor;

[0068] S2: preparing a viscosity adjusting additive

[0069] Tannic acid, ethyl acetate and butyl acetate were added to a reaction tank at a solid-liquid ratio of 20 g:20 mL:9 mL, heated at 90° C., stirred at a rate of 300 r / min for 40 min, and fully mixed to obtain a mixed solution A. Then, while keeping the heating temperature constant and adjusting the stirring rate to 200 r / min, triphenylphosphine and hydroquinone monomethyl ether were added to the mixed solution A while stirring, and stirring was continued for 30 min to obtain a mixed solution B, wherein the mass ratio of triphenylphosphine to tannic acid was 1:20, and the mass ratio of hydroquinone monomethyl ether to tannic acid was 1:300. Subsequently, while keeping the heating temperature and stirring rate constant, glycidyl methacrylate and Versatic acid glycidyl ester were added to the mixed solution B while stirring, and the reaction was heated for 12 h. The solvent was removed by distillation under reduced pressure to obtain a viscosity regulating additive, wherein the mass ratios of glycidyl methacrylate and Versatic acid glycidyl ester to tannic acid were 2:1 and 1:1.8, respectively.

[0070] S3: Preparation of anti-corrosion additives

[0071] n-Bromooctane, n-Bromodecane and tri-n-butylphosphine were stirred and mixed uniformly in a mass ratio of 1:1.4:1.2, and then heated at 150°C for 12 hours under nitrogen protection for reflux reaction. Impurities were removed by reduced pressure distillation to obtain intermediate A, and then intermediate A was added to methanol in a mass ratio of 1:70, stirred and dissolved to obtain intermediate A solution, which was set aside. Mercaptobenzothiazole and potassium hydroxide were added to methanol in a solid-liquid ratio of 5g:1g:30mL, stirred and dissolved to obtain a ternary mixed solution, which was set aside. Subsequently, intermediate A was added to methanol in a solid-liquid ratio of 5g:1g:30mL, stirred and dissolved to obtain a ternary mixed solution, which was set aside. The intermediate A solution is added to the above ternary mixed solution, and then stirred at a rate of 500 r / min for 3 hours to react to obtain a suspension, wherein the molar ratio of mercaptobenzothiazole to intermediate A is 1:1.4, and then the suspension is placed in a centrifuge and centrifuged to remove solid impurities. The filtrate is then subjected to rotary evaporation to remove the solvent and water to obtain intermediate B. Finally, intermediate B is added to anhydrous ethanol, fully stirred to dissolve, and after centrifugal filtration and rotary evaporation, placed in a vacuum drying oven and vacuum dried for 2 hours to obtain an anticorrosive additive;

[0072] S4: Mix the components to prepare sealing grease

[0073] Add 20 parts of polyether ester, 3 parts of the above-mentioned anti-rust additive, 18 parts of the above-mentioned viscosity regulating additive and 10 parts of the above-mentioned anti-corrosion additive to a kneader and knead for 40 minutes. Then add 16 parts of lithium-based grease to the kneader and continue kneading for 50 minutes. Then, add 15 parts of cellulose fiber to the kneader and continue kneading for 30 minutes. Then, add 30 parts of talc powder to the kneader and continue kneading for 3 hours to obtain sealing grease.

[0074] The quality test indicators of the sealing grease prepared in Examples 1-3 of the present invention are shown in Table 1 below:

[0075] Table 1: Summary of quality test indicators of sealing greases prepared in Examples 1-3

[0076] Test item Example 1 Example 2 Example 3 Sealing property (25°C) MPa 3.5 3.5 3.4 Volatility (80°C, 5h) % 0.12 0.13 0.16 Maximum peeling force (25°C) N 154 152 155 Abrasion scar diameter (load 800N, 1h) mm 0.85 0.88 0.91 Rust preventive property (iron sheet, 100°C, 24h) No rust No rust No rust

[0077] Comparative Example 1

[0078] The difference between Comparative Example 1 and Example 1 is that the anti-corrosion additive in step S4 is removed, and the quality test indicators of the sealing grease obtained are shown in Table 2 below:

[0079] Table 2: Comparison of sealing grease quality test indicators of Example 1 and Comparative Example 1

[0080] Test item Example 1 Comparative Example 1 Volatility (80°C, 5h) % 0.12 0.96 Abrasion scar diameter (load 800N, 1h) mm 0.85 1.63

[0081] By comparing the sealing grease quality test indicators of Example 1 and Comparative Example 1, it can be seen that the volatility and wear spot diameter of the sealing grease prepared in Comparative Example 1 without adding the anti-corrosion additive are 0.96% and 1.63 mm, respectively, which are both larger than the sealing grease prepared in Example 1. It can be seen that the anti-corrosion additive is prepared by first mixing n-octane bromide, n-decane bromide and tri-n-butylphosphine for reaction, and then adding it to a mixed solution of mercaptobenzothiazole and potassium hydroxide for continued reaction. After adding it to the sealing grease, on the one hand, the mercapto group can effectively capture the free radicals generated during the oxidation of the sealing grease and interrupt the grease oxidation chain reaction. On the other hand, the anti-corrosion additive can form a stable complex with metal ions, effectively inhibit the catalytic effect of the metal surface, and reduce the oxidation reaction initiated by the metal, thereby achieving the effect of delaying the aging of the grease and improving the corrosion resistance of the grease. In addition, due to the friction between the anti-corrosion additive and the metal, a tribochemical reaction will occur to generate tribochemical products containing the S element, and these products can form a boundary lubricating film together with the oxide on the metal surface, showing a friction-reducing and anti-wear effect, thereby improving the wear resistance of the sealing grease.

[0082] Comparative Example 2

[0083] The difference between Comparative Example 2 and Example 1 is that the viscosity regulating additive in step S4 is removed, and the quality test indicators of the sealing grease obtained are shown in Table 3 below:

[0084] Table 3: Comparison of sealing grease quality test indicators of Example 1 and Comparative Example 2

[0085] Test item Example 1 Comparative Example 2 Sealing property (25°C) MPa 3.5 2.6 Maximum peeling force (25°C) N 154 113

[0086] From the sealing grease quality detection indexes of Comparative Example 1 and Comparative Example 2, it can be seen that the sealing property and the maximum peeling force of Comparative Example 2 are 2.6 MPa and 113 N respectively, both of which are less than those of Example 1. It can be seen that, by mixing tannic acid, triphenylphosphine and p-benzenediol monomethyl ether by heating and stirring, then adding glycidyl methacrylate and glycidyl ester of Versatic acid to react, the viscosity adjusting additive is prepared. After the viscosity adjusting additive is added into the sealing grease, a three-dimensional cross-linked network is formed in the sealing grease, the relative sliding between grease molecules is reduced, the intermolecular friction is increased, the overall structural strength and viscosity are enhanced, so that the sealing property and the adhesion of the sealing grease are improved, which is helpful to form a more stable sealing layer.

[0087] Comparative Example 3

[0088] The difference between the present comparative example 3 and Example 1 is that the rust-proof additive in step S4 is removed. The sealing grease quality detection indexes of the sealing grease prepared by Comparative Example 3 are shown in Table 4.

[0089] Table 4: Comparison table of sealing grease quality detection indexes of Example 1 and Comparative Example 3

[0090] Test item Example 1 Comparative Example 3 Rust preventive property (iron sheet, 100°C, 24h) No rust Rust

[0091] From the sealing grease quality detection indexes of Comparative Example 1 and Comparative Example 3, it can be seen that the sealing grease prepared by Comparative Example 3 without adding the rust-proof additive cannot prevent the metal surface from being eroded by water and corrosion medium, while the sealing grease prepared by Example 1 with adding the rust-proof additive can effectively prevent the metal surface from being eroded by water and corrosion medium. Therefore, it can be known that, by mixing methyl oleate and maleic anhydride by heating to react, then mixing with distilled water to hydrolyze, the rust-proof additive is prepared. Since the carboxyl end of the rust-proof additive is easy to be chemically adsorbed on the metal surface to form a dense adsorption film, the rust-proof additive can prevent air and water from contacting the metal to cause rust. Therefore, by adding the rust-proof additive into the sealing grease, the rust-proof property of the sealing grease can be effectively improved.

[0092] The above examples only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease, characterized in that: The steps include: S1: Preparation of anti-rust additives Methyl oleate and maleic anhydride are mixed and heated to react, distilled under reduced pressure, then mixed with distilled water and heated to carry out hydrolysis reaction, and distilled under reduced pressure again to obtain a rust-proof additive; S2: Preparation of viscosity-adjusting additives Tannic acid, ethyl acetate, butyl acetate, triphenylphosphine and hydroquinone monomethyl ether are stirred and mixed, glycidyl methacrylate and glycidyl versatic acid ester are added, and heated to react to obtain a viscosity regulating additive; S3: Preparation of anti-corrosion additives n-octane bromide, n-decane bromide, and tri-n-butylphosphine are uniformly mixed and reacted to prepare an intermediate A, and the intermediate A is dissolved in methanol to form an intermediate A solution, which is set aside. Then, mercaptobenzothiazole and potassium hydroxide are dissolved in methanol to prepare a ternary mixed solution, which is set aside. Subsequently, the intermediate A solution is added to the ternary mixed solution to react to obtain an anti-corrosion additive; S4: Mix the components to prepare sealing grease Add the base oil, the above-mentioned rust-proof additive, the above-mentioned viscosity-adjusting additive and the above-mentioned anti-corrosion additive into a kneader and knead for 30-40 minutes. Then add the grease into the kneader and continue kneading for 40-50 minutes. Then add the fiber into the kneader and continue kneading for 20-30 minutes. Then add the filler into the kneader and continue kneading for 2-3 hours to obtain the sealing grease.

2. The process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease according to claim 1, characterized in that: S1 specifically includes the following steps: S1.1: Add methyl oleate and maleic anhydride in a molar ratio of 1:1.3-1.8 to a reactor, stir and mix thoroughly, heat at 200-260°C for 8-10 hours, and cool naturally to room temperature to obtain a crude product. S1.2: The crude product is placed in a vacuum distiller and distilled under reduced pressure to remove impurities. After cooling naturally to room temperature, a precursor is obtained. S1.3: The above precursor and distilled water are stirred and mixed uniformly in a molar ratio of 1:(3-5), and then heated at a temperature of 60-80°C for 6-8h to carry out a hydrolysis reaction, and then excess distilled water is removed by vacuum distillation to obtain an anti-rust additive.

3. The process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease according to claim 1, characterized in that: S2 specifically includes the following steps: S2.1: Mix tannic acid, ethyl acetate and butyl acetate in a solid-liquid ratio of (15-20) g: (16-20) mL: (7-9) mL was added to a reaction tank, heated at 80-90°C, stirred at 200-300 rpm for 30-40 min, and thoroughly mixed to obtain a mixed solution A; S2.2: Maintaining the heating temperature, adjust the stirring rate to 100-200 r / min, and add triphenylphosphine and hydroquinone monomethyl ether to the above mixed solution A while stirring. Continue stirring for 20-30 minutes to obtain a mixed solution B; S2.3: While maintaining the heating temperature and stirring rate, add glycidyl methacrylate and glycidyl versatic acid to the mixed solution B while stirring. Heat and react for 10-12 hours. Remove the solvent by distillation under reduced pressure to obtain a viscosity regulating additive.

4. The process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease according to claim 1, characterized in that: S3 specifically includes the following steps: S3.1: Mix n-octane bromide, n-decane bromide, and tri-n-butylphosphine in a mass ratio of 1:(1.2-1.4):(1-1.2), then heat at 140-150°C under nitrogen for 10-12 hours for reflux reaction. Remove impurities by distillation under reduced pressure to obtain Intermediate A. S3.2: Add the intermediate A to methanol at a mass ratio of 1:(60-70), stir thoroughly to dissolve, and obtain an intermediate A solution; S3.3: Add mercaptobenzothiazole and potassium hydroxide to methanol at a solid-liquid ratio of (3-5) g:1 g:(20-30) mL and stir thoroughly to dissolve to obtain a ternary mixture. S3.4: Add the intermediate A solution to the ternary mixture, and then stir at 400-500 rpm for 2-3 hours to react to obtain a suspension, wherein the molar ratio of mercaptobenzothiazole to intermediate A is 1:(1-1.4); S3.5: Place the suspension in a centrifuge and filter it to remove solid impurities. Then, evaporating the filtrate to remove the solvent and water, yielding Intermediate B. S3.6: Add the intermediate B mentioned above to anhydrous ethanol, stir thoroughly to dissolve, centrifuge and evaporating, place in a vacuum drying oven, and vacuum dry for 1-2 hours to obtain the anti-corrosion additive.

5. The process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease according to claim 3, characterized in that: The mass ratio of triphenylphosphine to tannic acid is 1:(18-20), and the mass ratio of hydroquinone monomethyl ether to tannic acid is 1:(280-300).

6. The process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease according to claim 3, characterized in that: The mass ratios of glycidyl methacrylate and glycidyl versatic acid to tannic acid are (1.6-2):1 and 1:(1.4-1.8), respectively.

7. The process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease according to claim 1, characterized in that: The sealing grease comprises, by weight, 16-20 parts of base oil, 10-18 parts of viscosity regulating additive, 8-10 parts of anti-corrosion additive, 1-3 parts of anti-rust additive, 12-16 parts of grease, 10-15 parts of fiber and 20-30 parts of filler; wherein the base oil is one or more of vegetable oil, polyol ester, polyester, polyether ester and glycerol.

8. The process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease according to claim 1, characterized in that: The fiber is one or more of cotton fiber, polylactic acid fiber, cellulose fiber, chitin fiber and animal fiber.

9. The process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease according to claim 1, characterized in that: The filler is one or more of calcium carbonate, bentonite, talc and kaolin.

10. The process for preparing an environmentally friendly, degradable, corrosion-resistant sealing grease according to claim 1, characterized in that: The lubricating grease is one or more of lithium-based lubricating grease, sulfurized lard, lanolin, molybdenum disulfide lubricating grease, and calcium-based lubricating grease.

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