An insulating sealing grease composition and a preparation method thereof

Abstract

This application belongs to the technical field of greases, and specifically discloses an insulating sealant grease composition and a preparation method thereof. The insulating sealant grease composition, in parts by weight, comprises the following raw materials: 60 - 90 parts of base oil, 2.5 - 3.5 parts of rust inhibitor, 7 - 12 parts of thickener, 11 - 15 parts of modified bentonite, 4 - 6 parts of calcium carbonate, 8 - 12 parts of modified asbestos fiber, 1.6 - 1.8 parts of surface modifier, and 2.4 - 2.7 parts of antioxidant. The insulating sealant grease composition prepared in this application has excellent electrical insulation performance, sealing performance, and heat resistance, can provide mechanical protection and sealing for components, reduce damage caused by vibration, impact, and wear, and extend the service life of components.

Description

Technical Field

[0001] The present application relates to the technical field of lubricating grease, and in particular to an insulating sealing grease composition and a preparation method thereof. Background Art

[0002] Sealing grease composition is a paste composed of liquid and solid materials, which is mainly used to meet the sealing function of the connection or sealing of the objects (such as workpieces) under a certain pressure. Its main components include liquid components and solid components. The liquid components are mostly organic liquids, such as mineral oil, silicone oil, etc. These liquid components provide the fluidity and lubricity of the sealing grease. The solid components include tiny particles of various sizes, both organic and inorganic. For example, graphite, white carbon black, talcum powder, polytetrafluoroethylene powder, asbestos wool, etc. These solid components enhance the sealing performance and high temperature resistance of the sealing grease.

[0003] In the prior art, the preparation method of the sealing grease composition generally includes mixing a base oil, a thickener, an organic filler and an inorganic filler, and then grinding the mixture to obtain a sealing grease product with excellent performance, which is widely used in multiple fields such as industry, construction, and automobiles, and has excellent sealing performance, lubricity, high temperature resistance, and chemical resistance. However, the base oil of common sealing greases available on the market is also mineral oil or ester-based synthetic oil, which generally has low viscosity, poor adhesion, and weak adhesion, thereby affecting the stability and sealing effect of the sealing grease. Summary of the invention

[0004] In order to improve the problems of low viscosity, poor adhesion and weak adhesion of common sealing grease, the present application provides an insulating sealing grease composition and a preparation method thereof.

[0005] The present application provides an insulating sealing grease composition, which adopts the following technical solution:

[0006] An insulating sealing grease composition comprises the following raw materials, measured by weight: 60-90 parts of base oil, 2.5-3.5 parts of rust inhibitor, 7-12 parts of thickener, 11-15 parts of modified bentonite, 4-6 parts of calcium carbonate, 8-12 parts of modified asbestos fiber, 1.6-1.8 parts of surface modifier and 2.4-2.7 parts of antioxidant.

[0007] By adopting the above technical solution, the base oil has good lubrication performance, fluidity and spreadability, can reduce the friction and wear of the components, extend the service life of the components, and improve the sealing effect. The base oil has excellent chemical stability and temperature resistance, can resist the erosion of various chemical substances, protect the components from corrosion, and the high dielectric strength and low dielectric constant of the base oil make it an ideal insulating medium, which helps to improve the electrical insulation performance of the sealing grease. The rust inhibitor can form a protective film to prevent the metal surface from contacting with corrosive substances such as oxygen and moisture in the air, further enhance the rust prevention effect of the sealing grease, and improve the chemical stability of the sealing grease composition, so that it can still maintain good performance in harsh environments.

[0008] Thickeners can convert liquid base oil into a semi-solid to solid structure. Through the thickening effect of thickeners, sealing grease can maintain its position in the complex structure of the component, provide continuous sealing and insulation effects, and maintain its shape and performance, prevent oil separation, and ensure the uniformity and consistency of the sealing grease during use. Modified bentonite has good colloidal properties, can effectively thicken the base oil, form a stable colloidal structure, and make the sealing grease difficult to flow. Modified bentonite can expand when exposed to water, fill irregular cavities, enhance the sealing performance of the sealing grease, and improve the temperature resistance and chemical stability of the composition.

[0009] Calcium carbonate increases the volume of sealing grease, and through its fine particle structure, it enhances the mechanical strength and hardness of the sealing grease, improves its wear resistance and pressure resistance, and can also improve the thixotropy of the sealing grease, maintaining a high viscosity when stationary, and reducing the viscosity when subjected to shear force, making it easier to apply and fill, while maintaining good shape stability after application. Modified asbestos fiber has a high tensile strength, which can significantly enhance the mechanical strength of the sealing grease, improve its wear resistance and pressure resistance, and make it less likely to be damaged when subjected to mechanical stress; it also has good high temperature resistance, sealing and chemical stability, which can enhance the stability and reliability of the sealing grease in high temperature environments, ensuring that it maintains its physical and chemical properties over a wide temperature range.

[0010] Surface modifiers can improve the dispersibility of various solid fillers (such as modified bentonite, calcium carbonate, and modified asbestos fibers) in sealing grease, ensuring that these components are evenly distributed in the base oil to avoid agglomeration and precipitation, thereby improving the overall performance and stability of the sealing grease. Antioxidants can capture and neutralize free radicals generated under high temperature and high pressure environments, preventing oxidation reactions of base oil and fillers, thereby improving the antioxidant stability of the sealing grease, extending the service life of the sealing grease, and reducing performance degradation and failure caused by oxidation. The insulating sealing grease composition obtained by mixing various components has excellent electrical insulation performance, sealing, and temperature resistance, can provide mechanical protection and sealing for components, reduce damage caused by vibration, impact, and wear, and extend the service life of components.

[0011] Preferably, the preparation method of the modified bentonite comprises the following steps:

[0012] (1) Disperse bentonite and dimethyloctadecylammonium salt in deionized water, stir at 60 - 65 °C for 30 - 35 min, filter, and dry to obtain pretreated bentonite;

[0013] (2) Disperse graphene in deionized water, add Triton X - 100 and modified viscose fiber, stir at a speed of 5000 - 5500 rpm for 20 - 25 min, and dry to obtain pretreated graphene;

[0014] (3) Disperse the pretreated bentonite obtained in step (1) in acetic acid solution, add the pretreated graphene and chitosan obtained in step (2), stir at 70 - 75 °C for 2 - 3 h, and dry to obtain modified bentonite.

[0015] By adopting the above technical solution, dimethyloctadecylammonium salt can be adsorbed on the surface of bentonite particles. Through electrostatic repulsion and steric hindrance effects, it can prevent the aggregation of bentonite particles, thereby improving its dispersibility in water, forming a stable suspension, which is helpful for the subsequent mixing of bentonite with other components.

[0016] Triton X - 100 can be adsorbed on the surface of graphene sheets. Through electrostatic repulsion and steric hindrance effects, it can prevent the aggregation of graphene sheets, improve the dispersibility of graphene in water, and form a stable graphene aqueous solution. The modified viscose fiber can be loaded on the surface of graphene. Graphene has extremely high strength and good thermochemical stability, which can enhance the mechanical strength and electrical insulation performance of the sealing grease and improve its sealing effect in complex environments. The viscose fiber can increase the flexibility and ductility of the sealing grease, enabling it to maintain good sealing performance under different temperature and pressure conditions. Triton X - 100 can improve the compatibility between graphene and viscose fiber, promote the uniform dispersion of the two in the aqueous solution, form a stable graphene / viscose fiber composite system, enhance the mechanical properties and functionality of the composite material, and the obtained pretreated graphene has good mechanical properties, thermal stability and corrosion resistance, extending its service life.

[0017] Mix the pretreated bentonite, pretreated graphene and chitosan. Graphene can be loaded on the surface and pores of bentonite, improving the mechanical properties, thermal stability and chemical stability of bentonite. Chitosan has a certain viscosity, making the bonding between bentonite and graphene tight. Graphene can be stably loaded on the surface of bentonite. The obtained modified bentonite has good mechanical properties, thermal stability and chemical stability, which can enhance the mechanical strength and flexibility of the sealing grease and improve its sealing effect in complex environments.

[0018] Preferably, the mass ratio of the bentonite, graphene, modified viscose fiber and chitosan is 1 g: 80-90 mg: 0.4-0.6 g: 0.1-0.2 g.

[0019] By adopting the above technical solution, the mass ratio of the bentonite, graphene, modified viscose fiber and chitosan is further limited within a certain range, and the obtained modified bentonite has better comprehensive performance. The high strength of graphene and the biopolymer characteristics of chitosan can enhance the mechanical strength and flexibility of the sealing grease, and improve its sealing effect in complex environments. The water absorption and swelling performance of bentonite can further enhance the sealing performance and self-healing ability of the sealing grease. The addition of viscose fiber increases the ductility and tear resistance of the sealing grease, making it perform better in a dynamic sealing environment.

[0020] The modified viscose fiber can be loaded on the surface of graphene, and the graphene loaded with the modified viscose fiber can be loaded on the surface of bentonite. Chitosan makes the bentonite, graphene and modified viscose fiber adhere tightly, so that the modified bentonite has good thermal stability, chemical stability, mechanical properties and sealing properties. Subsequently, when applied to the insulating sealing grease composition, the obtained sealing grease has good mechanical strength, flexibility, sealing performance and self-healing ability.

[0021] Preferably, the preparation method of the modified viscose fiber includes the following steps: dispersing viscose fiber in sodium hydroxide solution, soaking for 1-2 h, washing with water, shearing to a length of 1-2 mm, grinding, then dispersing in deionized water, adding silver nanowires and hydroxyethyl cellulose, stirring for 2-3 h, and drying to obtain the modified viscose fiber.

[0022] By adopting the above technical solution, treating the viscose fiber with sodium hydroxide solution changes the surface properties of the viscose fiber, increases the solubility of the viscose fiber, removes residual chemical substances, and improves the purity and performance of the fiber.

[0023] Silver nanowires can be loaded on the surface of viscose fiber, improving the antibacterial property, compatibility and mechanical properties of the viscose fiber. Hydroxyethyl cellulose has good film-forming property and adhesiveness. Hydroxyethyl cellulose enhances the binding force between silver nanowires and viscose fiber, improving the mechanical strength and stability of the modified adhesive fiber. Subsequently, when applied to modified bentonite, it increases the adhesion between the components in the bentonite, making the modified bentonite have better comprehensive performance. When subsequently applied to the sealing grease, it increases the mechanical strength, sealing performance and stability of the sealing grease.

[0024] Preferably, the preparation method of the modified asbestos fiber includes the following steps:

[0025] (1) Cut the asbestos fibers into small segments with a length of 3 - 5 mm, soak them in an ammonium chloride aqueous solution with a mass concentration of 5 - 20%, treat them at a temperature of 80 - 100 °C for 2 - 3 h, then disperse them in absolute ethanol for cleaning, filtration, and drying to obtain pretreated asbestos fibers;

[0026] (2) Disperse the pretreated silica in deionized water, add polyvinyl alcohol, and ultrasonicate for 1 - 2 h to obtain a mixed solution for standby;

[0027] (3) Disperse the pretreated asbestos fibers from step (1) in deionized water, add the mixed solution from step (2) and xanthan gum, stir for 2 - 3 h, and dry to obtain modified asbestos fibers.

[0028] By adopting the above technical solution, the asbestos fibers are treated with an ammonium chloride aqueous solution, and the surface properties of the asbestos fibers are changed through a chemical reaction. The ammonium ions in ammonium chloride can act with the active groups on the surface of the asbestos fibers, affecting the charge state of the fibers, thereby changing their dispersibility in water and compatibility with other materials.

[0029] The pretreated silica is dispersed in deionized water. The hydroxyl groups in the polyvinyl alcohol molecules can form hydrogen bonds with the hydroxyl groups on the surface of the silica. This hydrogen bond action helps the dispersion of silica particles in the polyvinyl alcohol matrix to obtain a stable mixed solution.

[0030] Disperse the pretreated asbestos fibers in deionized water, add the mixed solution and epoxy resin. The silica can be loaded on the surface of the asbestos fibers, improving the dispersibility of the asbestos fibers in deionized water and reducing the agglomeration phenomenon. The asbestos fibers have excellent heat resistance, chemical corrosion resistance, and insulation properties, while the silica has a high specific surface area, good dispersibility, and reinforcing effect. The combination of the two can enhance the mechanical properties, thermal stability, and chemical stability of the composite material. Xanthan gum has a certain viscosity, making the silica and asbestos fibers adhere tightly, increasing the performance stability of the modified asbestos fibers. When applied to the sealing grease composition later, it improves the mechanical properties, thermal / chemical stability, and sealing performance of the sealing grease composition.

[0031] Preferably, the mass ratio of the asbestos fibers, pretreated silica, and xanthan gum is 1:0.4 - 0.5:0.1 - 0.2.

[0032] By adopting the above technical solution, the mass ratio of asbestos fiber, pretreated silica white and xanthan gum is further limited within a certain range to improve the comprehensive performance of asbestos fiber. Asbestos fiber has good heat resistance and chemical stability, while pretreated silica white can improve the viscosity and consistency of the sealing grease. The combination of the two can form a tighter sealing layer and improve the sealing effect. Xanthan gum makes the pretreated silica white and asbestos fiber bond tightly, and there is a synergistic effect among asbestos fiber, pretreated silica white and xanthan gum, so that the modified asbestos fiber has excellent chemical stability, heat resistance, mechanical properties and sealing properties.

[0033] Preferably, the preparation method of the pretreated silica white includes the following steps: dispersing silica white in an aqueous solution of silane coupling agent, stirring at a temperature of 70-80 °C for 1-2 h, adding sodium dodecyl sulfonate and nano-titanium dioxide, continuing to stir, filtering, and drying to obtain the pretreated silica white.

[0034] By adopting the above technical solution, the silane coupling agent can reduce the interaction force between silica white particles by reacting with the hydroxyl groups on the surface of silica white, reduce secondary agglomeration, and thus significantly improve the dispersibility of silica white in water.

[0035] Silica white can improve the consistency and viscosity of the sealing grease, form a tighter sealing layer, and enhance the sealing effect. Nano-titanium dioxide has good chemical stability, can improve the resistance of the sealing grease to chemical substances such as acids, alkalis and solvents, and extend the service life of the sealing grease. Nano-titanium dioxide can be loaded in the pores and on the surface of silica white, further improving the weather resistance and corrosion resistance of the sealing grease and enhancing its sealing performance in harsh environments.

[0036] Sodium dodecyl sulfonate improves the dispersibility of silica white and nano-titanium dioxide in the sealing grease matrix, prevents particle agglomeration, and at the same time improves the stability of the sealing grease, avoiding stratification or precipitation during storage and use. The combination of silica white, sodium dodecyl sulfonate and nano-titanium dioxide improves the mechanical properties, chemical stability, heat resistance and sealing performance of the system. The obtained pretreated silica white has excellent comprehensive performance and is subsequently applied to the sealing grease composition to improve the comprehensive performance of the composition.

[0037] Preferably, the base oil is selected from one or more of saturated polyol esters, diesters, complex esters, aromatic esters and vegetable oils.

[0038] By adopting the above technical solution, ester oils can well improve the anti-wear performance of the base oil, and can achieve good anti-wear effects even at low concentrations (such as 5-10%), and also have good chemical stability, can resist the erosion of chemical substances such as acids, alkalis and solvents, and extend the service life of lubricating materials, especially in harsh chemical environments.

[0039] Preferably, the antioxidant is selected from amine antioxidants or phenolic antioxidants.

[0040] By adopting the above technical solution, amine antioxidants and phenolic antioxidants can effectively inhibit the aging process of polymers in a thermal-oxidative environment. By interrupting the free radical chain reaction, they can prevent the breakage and crosslinking of polymer molecular chains, thereby maintaining the mechanical properties and appearance of the material. The antioxidant can also resist the erosion of chemical substances such as acids, alkalis, and solvents, and extend the service life of polymer materials.

[0041] In a second aspect, the present application also provides a method for preparing an insulating sealant grease composition, comprising the following steps: heating the base oil to 90 - 95 °C, adding a rust inhibitor and a thickening agent, raising the temperature to 120 - 125 °C, maintaining the temperature for 60 - 65 min, then adding modified bentonite, calcium carbonate, modified asbestos fiber, a surface modifier, and an antioxidant, and performing a constant temperature and constant pressure dehydration reaction under a vacuum degree of -0.05 to -0.1 MPa to obtain a mixture, and rolling and grinding the mixture to obtain the insulating sealant grease composition.

[0042] By adopting the above technical solution and the above preparation method, the operation is simple and the process time is short, which helps to improve the production efficiency of preparing the insulating sealant grease composition. The obtained insulating sealant grease composition has good mechanical properties, wear resistance, and sealing performance.

[0043] In summary, the present application has the following beneficial effects:

[0044] 1. When the various components in the present application are mixed, the obtained insulating sealant grease composition has excellent electrical insulation performance, sealing performance, and heat resistance, can provide mechanical protection and sealing for components, reduce damage caused by vibration, impact, and wear, and extend the service life of components.

[0045] 2. The modified bentonite in the present application has good colloidal properties, can effectively thicken the base oil, form a stable colloidal structure, make the sealant grease not easy to flow, and the modified bentonite can expand when contacting water, fill irregular cavities, enhance the sealing performance of the sealant grease, and improve the heat resistance and chemical stability of the composition.

[0046] 3. The modified asbestos fiber in the present application has a relatively high tensile strength, can significantly enhance the mechanical strength of the sealant grease, improve its wear resistance and pressure resistance, and also has good high-temperature resistance, sealing performance, and chemical stability, can enhance the stability and reliability of the sealant grease in a high-temperature environment, and ensure that it maintains physical and chemical properties within a wide temperature range. Detailed Embodiments

[0047] The following further elaborates on the present application with reference to embodiments.

[0048] The raw materials used in the examples and comparative examples are all commercially available.

[0049] Preparation Example of Modified Bentonite

[0050] Preparation Example 1-1

[0051] The preparation method of the modified bentonite includes the following steps:

[0052] (1) 1.2 kg of bentonite and 0.3 kg of dimethyloctadecylquaternary ammonium salt were dispersed in 2 L of deionized water, stirred at 65 °C for 35 min, filtered, and dried to obtain pretreated bentonite; the dimethyloctadecylquaternary ammonium salt was Quaternary Ammonium Salt-18, purchased from Hubei Shineng Chemical Technology Co., Ltd.;

[0053] (2) Graphene was dispersed in 1.2 L of deionized water, 0.05 g of Triton X-100 and modified viscose fiber were added, and stirred at a speed of 5500 rpm for 25 min, and then dried to obtain pretreated graphene;

[0054] (3) The pretreated bentonite obtained in step (1) was dispersed in 3.5 L of acetic acid solution with a mass fraction of 10%, the pretreated graphene and chitosan obtained in step (2) were added, and stirred at 75 °C for 3 h, and then dried to obtain the modified bentonite.

[0055] The mass ratio of bentonite, graphene, modified viscose fiber and chitosan is 1 g: 90 mg: 0.4 g: 0.1 g.

[0056] The preparation method of the modified viscose fiber includes the following steps: 1 kg of viscose fiber was dispersed in 2 L of sodium hydroxide solution with a mass fraction of 12%, soaked for 1.5 h, washed with water, sheared to a length of 1-2 mm, ground, and then dispersed in 3 L of deionized water, 0.3 kg of silver nanowires and 0.1 kg of hydroxyethyl cellulose were added, and stirred for 3 h, and then dried to obtain the modified viscose fiber.

[0057] The viscose fiber was purchased from Shandong Fuhui Textile Technology Co., Ltd.

[0058] Preparation Example 1-2

[0059] The difference from Preparation Example 1-1 is that in step (2), graphene is not added.

[0060] Preparation Example 1-3

[0061] The difference from Preparation Example 1-1 is that in step (2), the modified viscose fiber is not added.

[0062] Preparation Example 1-4

[0063] The difference from Preparation Example 1-1 is that in step (3), chitosan is not added.

[0064] Preparation Examples 1-5

[0065] It is different from Preparation Example 1-1 in that the mass ratio of bentonite, graphene, modified viscose fiber and chitosan is 1 g: 80 mg: 0.6 g: 0.2 g.

[0066] Preparation Example 1-6

[0067] It is different from Preparation Example 1-1 in that the mass ratio of bentonite, graphene, modified viscose fiber and chitosan is 1 g: 60 mg: 0.1 g: 0.8 g.

[0068] Preparation Example 1-7

[0069] It is different from Preparation Example 1-1 in that silver nanowires are not added in the preparation method of the modified viscose fiber.

[0070] Preparation Example 1-8

[0071] It is different from Preparation Example 1-1 in that hydroxyethyl cellulose is not added in the preparation method of the modified viscose fiber.

[0072] Preparation Examples of Modified Asbestos Fibers

[0073] Preparation Example 2-1

[0074] The preparation method of the modified asbestos fiber includes the following steps:

[0075] (1) Cut 1.5 kg of asbestos fiber into small pieces with a length of 3-5 mm, soak them in 3 L of ammonium chloride aqueous solution with a mass concentration of 5%, treat them at 90 °C for 3 h, then disperse them in 5 L of absolute ethanol for cleaning, filtration, and drying to obtain pretreated asbestos fiber;

[0076] (2) Disperse the pretreated white carbon black in 2 L of deionized water, add 0.1 kg of polyvinyl alcohol, and ultrasonicate for 2 h to obtain a mixed solution for standby;

[0077] (3) Disperse the pretreated asbestos fiber in step (1) in 2 L of deionized water, add the mixed solution in step (2) and xanthan gum, stir for 3 h, and dry to obtain the modified asbestos fiber.

[0078] The mass ratio of asbestos fiber, pretreated white carbon black and xanthan gum is 1: 0.4: 0.1.

[0079] The preparation method of the pretreated white carbon black includes the following steps: Disperse 2 kg of white carbon black in 3 L of an aqueous solution of silane coupling agent KH550 with a mass fraction of 0.02%, stir at 76 °C for 2 h, add 0.06 kg of sodium dodecyl sulfate and 0.3 kg of nano-titanium dioxide, continue stirring, filter, and dry to obtain the pretreated white carbon black.

[0080] Preparation Example 2-2

[0081] The difference from Preparation Example 2-1 is that in step (2), no pretreated silica is added.

[0082] Preparation Example 2-3

[0083] The difference from Preparation Example 2-1 is that in step (3), no xanthan gum is added.

[0084] Preparation Example 2-4

[0085] The difference from Preparation Example 2-1 is that the mass ratio of asbestos fiber, pretreated silica and xanthan gum is 1:0.5:0.2.

[0086] Preparation Example 2-5

[0087] The difference from Preparation Example 2-1 is that the mass ratio of asbestos fiber, pretreated silica and xanthan gum is 1:0.1:0.5.

[0088] Preparation Example 2-6

[0089] The difference from Preparation Example 2-1 is that sodium dodecyl sulfate is not added in the preparation method of pretreated silica.

[0090] Preparation Example 2-7

[0091] The difference from Preparation Example 2-1 is that in the preparation method of pretreated white carbon black, no nano titanium dioxide is added.

[0092] Example

[0093] Example 1 An insulating sealing grease composition comprises the following raw materials by weight: 90 kg of base oil, 2.5 kg of rust inhibitor, 7 kg of thickener, 11 kg of modified bentonite, 4 kg of calcium carbonate, 12 kg of modified asbestos fiber, 1.6 kg of surface modifier, and 2.4 kg of antioxidant;

[0094] The base oil is selected from saturated polyol ester, specifically saturated polyol ester Priolube 3970, purchased from Dongguan Hersby New Materials Co., Ltd. The rust inhibitor is 2,5-disulfide-1,3,4-thiadiazole derivative T561, the thickener is polytrifluorochloroethylene powder, item number M300H, purchased from Dongguan Hongming New Materials Co., Ltd.; the surface modifier is dimethyldiethoxysilane, and the antioxidant is selected from antioxidant 5057.

[0095] The preparation method of the above-mentioned insulating sealing grease composition comprises the following steps: heating the base oil to 95 °C, adding a rust inhibitor and a thickening agent, raising the temperature to 125 °C, holding the temperature for 65 min, then adding modified bentonite, calcium carbonate, modified asbestos fiber, a surface modifier, and an antioxidant, and carrying out a constant-temperature and constant-pressure dehydration reaction under a vacuum degree of -0.05 MPa to obtain a mixture, and rolling and grinding the mixture to obtain the insulating sealing grease composition.

[0096] The modified bentonite is prepared by Preparation Example 1-1; the modified asbestos fiber is prepared by Preparation Example 2-1.

[0097] Example 2

[0098] An insulating sealing grease composition, which is different from that of Example 1, comprises the following raw materials by weight: 60 kg of base oil, 3.5 kg of rust inhibitor, 12 kg of thickening agent, 15 kg of modified bentonite, 6 kg of calcium carbonate, 8 kg of modified asbestos fiber, 1.8 kg of surface modifier, and 2.7 kg of antioxidant.

[0099] Example 3

[0100] An insulating sealing grease composition, which is different from that of Example 1, is characterized in that the modified bentonite is prepared by Preparation Example 1-2.

[0101] Example 4

[0102] An insulating sealing grease composition, which is different from that of Example 1, is characterized in that the modified bentonite is prepared by Preparation Example 1-3.

[0103] Example 5

[0104] An insulating sealing grease composition, which is different from that of Example 1, is characterized in that the modified bentonite is prepared by Preparation Example 1-4.

[0105] Example 6

[0106] An insulating sealing grease composition, which is different from that of Example 1, is characterized in that the modified bentonite is prepared by Preparation Example 1-5.

[0107] Example 7

[0108] An insulating sealing grease composition, which is different from that of Example 1, is characterized in that the modified bentonite is prepared by Preparation Example 1-6.

[0109] Example 8

[0110] An insulating sealing grease composition, which is different from that of Example 1, is characterized in that the modified bentonite is prepared by Preparation Example 1-7.

[0111] Example 9

[0112] An insulating sealant grease composition, which is different from that of Example 1 in that the modified bentonite is prepared by Preparation Example 1-8.

[0113] Example 10

[0114] An insulating sealant grease composition, which is different from that of Example 1 in that the modified asbestos fiber is prepared by Preparation Example 2-2.

[0115] Example 11

[0116] An insulating sealant grease composition, which is different from that of Example 1 in that the modified asbestos fiber is prepared by Preparation Example 2-3.

[0117] Example 12

[0118] An insulating sealant grease composition, which is different from that of Example 1 in that the modified asbestos fiber is prepared by Preparation Example 2-4.

[0119] Example 13

[0120] An insulating sealant grease composition, which is different from that of Example 1 in that the modified asbestos fiber is prepared by Preparation Example 2-5.

[0121] Example 14

[0122] An insulating sealant grease composition, which is different from that of Example 1 in that the modified asbestos fiber is prepared by Preparation Example 2-6.

[0123] Example 15

[0124] An insulating sealant grease composition, which is different from that of Example 1 in that the modified asbestos fiber is prepared by Preparation Example 2-7.

[0125] Comparative Example

[0126] Comparative Example 1

[0127] An insulating sealant grease composition, which is different from that of Example 1 in that no modified bentonite is added.

[0128] Comparative Example 2

[0129] An insulating sealant grease composition, which is different from that of Example 1 in that the modified bentonite is replaced with an equal amount of bentonite.

[0130] Comparative Example 3

[0131] An insulating sealant grease composition, which is different from that of Example 1 in that no modified asbestos fiber is added.

[0132] Comparative Example 4

[0133] An insulating sealant composition, which is different from that of Example 1 in that the modified asbestos fiber is replaced with an equal amount of asbestos fiber.

[0134] Performance detection test

[0135] The insulating sealant compositions prepared in Examples 1-15 and Comparative Examples 1-4 were subjected to performance tests. The reference standards for each performance test are listed in Table 1, and the test results are shown in Table 1.

[0136] Table 1 Test data of examples and comparative examples

[0137]

[0138] As can be seen from Table 1, the insulating sealant compositions prepared in Examples 1-2 of the present application have good sealing performance, stability, wear resistance and durability. Among them, the penetration of Example 1 is 60 mm, the evaporation loss is 0.08 w / w%, the bleeding oil is 0, and the gas permeability is 2 cm 3 , the friction coefficient is 0.47, and the change rate of penetration in the aging test is 1.5%. It shows that the prepared insulating sealant composition has excellent electrical insulation performance, sealing performance and heat resistance, improves the chemical stability of the sealant composition, and enables it to maintain good performance in harsh environments.

[0139] In the preparation methods of modified bentonite in Examples 3-5, graphene, modified viscose fiber and chitosan were not added respectively. In Examples 6-7, the mass ratios of bentonite, graphene, modified viscose fiber and chitosan were changed. As can be seen from Table 1, the performances of penetration, evaporation loss, bleeding oil, gas permeability, friction coefficient and change rate of penetration in the aging test of Examples 3-5 are all worse than those of Examples 1-2 and Example 6. The above performance effects of Example 7 are better than those of Examples 3-5, but worse than those of Examples 1-2 and Example 6, indicating that the high strength of graphene and the biopolymer characteristics of chitosan can enhance the mechanical strength and flexibility of the sealant, improve its sealing effect in complex environments, and the water absorption and swelling performance of bentonite can further enhance the sealing performance and self-healing ability of the sealant. The addition of viscose fiber increases the ductility and tear resistance of the sealant, making it perform better in dynamic sealing environments.

[0140] In the preparation methods of the modified viscose fibers in Examples 8 - 9, silver nanowires and hydroxyethyl cellulose are not added respectively. As can be seen from Table 1, the performances of the penetration, evaporation loss, oil separation amount, air permeability, friction coefficient, and the change rate of penetration in the aging test of Examples 8 - 9 are all better than those of Example 4, but worse than those of Examples 1 - 2, indicating that silver nanowires can be loaded on the surface of viscose fibers, improving the antibacterial property, compatibility, and mechanical properties of viscose fibers. Hydroxyethyl cellulose has good film-forming property and adhesiveness, and hydroxyethyl cellulose enhances the binding force between silver nanowires and viscose fibers. When subsequently applied to modified bentonite, it increases the adhesiveness between the components in bentonite, and subsequently increases the mechanical strength, sealing property, and stability of the sealing grease.

[0141] In the preparation methods of the modified asbestos fibers in Examples 10 - 11, pre-treated silica white and xanthan gum are not added respectively. In Examples 12 - 13, the mass ratios of asbestos fibers, silica white, and xanthan gum are changed. As can be seen from Table 1, the performances of the penetration, evaporation loss, oil separation amount, air permeability, friction coefficient, and the change rate of penetration in the aging test of Examples 10 - 11 are all worse than those of Examples 1 - 2 and Example 12. The above performance effects of Example 13 are all better than those of Examples 10 - 11, but worse than those of Examples 1 - 2 and Example 12, indicating that asbestos fibers have good heat resistance and chemical stability, silica white can improve the viscosity and consistency of the sealing grease, and the combination of the two can form a tighter sealing layer to improve the sealing effect. Xanthan gum makes the silica white and asbestos fibers adhere tightly, and the modified asbestos fibers have excellent chemical stability, heat resistance, mechanical properties, and sealing properties.

[0142] In the preparation methods of the pre-treated silica white in Examples 14 - 15, sodium dodecyl sulfate and nano-titanium dioxide are not added respectively. As can be seen from Table 1, the performances of the penetration, evaporation loss, oil separation amount, air permeability, friction coefficient, and the change rate of penetration in the aging test of Examples 14 - 15 are all better than those of Example 10, but worse than those of Examples 1 - 2, indicating that the combination of silica white, sodium dodecyl sulfate, and nano-titanium dioxide improves the mechanical properties, chemical stability, heat resistance, and sealing properties of the system, and the obtained pre-treated silica white has excellent comprehensive properties. When subsequently applied to the sealing grease composition, it improves the comprehensive properties of the composition.

[0143] Comparative Examples 1 and 3 do not add modified bentonite and modified asbestos fiber, respectively. As can be seen from Table 1, compared with Example 1, the performance test results of cone penetration, evaporation loss, oil separation, air permeability, friction coefficient, and aging test cone penetration change rate of Comparative Examples 1 and 3 are significantly worse than those of Examples 1-2, indicating that the modified bentonite has good colloidal properties, can effectively thicken the base oil, fill irregular voids, enhance the sealing performance of the sealing grease, and improve the temperature resistance and chemical stability of the composition; the modified asbestos fiber has a high tensile strength, can significantly enhance the mechanical strength of the sealing grease, improve its wear resistance and pressure resistance, and make it not easily damaged when subjected to mechanical stress.

[0144] In Comparative Examples 2 and 4, the modified bentonite is replaced by an equal amount of bentonite, and the modified asbestos fiber is replaced by an equal amount of asbestos fiber. It can be seen from Table 1 that compared with Example 1, the test results of the cone penetration, evaporation loss, oil separation, air permeability, friction coefficient, and aging test cone penetration change rate of Comparative Examples 2 and 4 are significantly worse than those of Examples 1-2, but better than those of Comparative Examples 1 and 3, indicating that the modified bentonite and modified asbestos fiber of the present application have good mechanical properties, mechanical properties and air tightness, and maintain the structural strength and performance stability of the sealing grease composition.

[0145] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An insulating sealing grease composition, characterized in that: The invention comprises the following raw materials in parts by weight: 60-90 parts of base oil, 2.5-3.5 parts of rust inhibitor, 7-12 parts of thickener, 11-15 parts of modified bentonite, 4-6 parts of calcium carbonate, 8-12 parts of modified asbestos fiber, 1.6-1.8 parts of surface modifier, and 2.4-2.7 parts of antioxidant; wherein the surface modifier is dimethyl diethoxy silane; The preparation method of the modified bentonite comprises the following steps: (1) Dispersing bentonite and dimethyl octadecyl quaternary ammonium salt in deionized water, stirring at a temperature of 60-65° C. for 30-35 minutes, filtering, and drying to obtain pretreated bentonite; (2) dispersing graphene in deionized water, adding Triton X-100 and modified viscose fiber, stirring at a speed of 5000-5500 rpm for 20-25 min, and drying to obtain pretreated graphene; (3) dispersing the pretreated bentonite in step (1) in an acetic acid solution, adding the pretreated graphene and chitosan in step (2), stirring at a temperature of 70-75° C. for 2-3 hours, and drying to obtain modified bentonite; The mass ratio of the bentonite, graphene, modified viscose fiber and chitosan is 1g:80-90mg:0.4-0.6g:0.1-0.2g; The preparation method of the modified viscose fiber comprises the following steps: dispersing the viscose fiber in a sodium hydroxide solution, soaking for 1-2 hours, washing with water, cutting to a length of 1-2 mm, grinding, and then dispersing in deionized water, adding silver nanowires and hydroxyethyl cellulose, stirring for 2-3 hours, and drying to obtain the modified viscose fiber; The preparation method of the modified asbestos fiber comprises the following steps: (1) Cutting the asbestos fibers into small pieces of 3-5 mm in length, immersing them in an aqueous solution of ammonium chloride with a mass concentration of 5-20%, treating them at a temperature of 80-100° C. for 2-3 hours, and then dispersing them in anhydrous ethanol for washing, filtering, and drying to obtain pretreated asbestos fibers; (2) Dispersing the pretreated silica in deionized water, adding polyvinyl alcohol, and ultrasonicating for 1-2 hours to obtain a mixed solution for later use; (3) dispersing the pretreated asbestos fiber of step (1) in deionized water, adding the mixed solution of step (2) and xanthan gum, stirring for 2-3 hours, and drying to obtain modified asbestos fiber; The mass ratio of the asbestos fiber, pretreated white carbon black and xanthan gum is 1:0.4-0.5:0.1-0.2; The preparation method of the pretreated white carbon black comprises the following steps: dispersing the white carbon black in a silane coupling agent aqueous solution, stirring for 1-2 hours at a temperature of 70-80° C., adding sodium dodecyl sulfonate and nano titanium dioxide, continuing stirring, filtering, and drying to obtain the pretreated white carbon black.

2. An insulating sealing grease composition according to claim 1, characterized in that: The antioxidant is selected from amine antioxidants or phenolic antioxidants.

3. The method for preparing an insulating sealing grease composition according to claim 1, characterized in that: The method comprises the following steps: heating the base oil to 90-95°C, adding a rust preventer and a thickener, raising the temperature to 120-125°C, keeping the temperature for 60-65 minutes, adding modified bentonite, calcium carbonate, modified asbestos fiber, a surface modifier and an antioxidant, and performing a constant temperature and pressure dehydration reaction at a vacuum degree of -0.05-0.1MPa to obtain a mixture, and rolling and grinding the mixture to obtain an insulating sealing grease composition.

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