Silicone Rubber Masterbatch and Its Preparation Method and Application

Abstract

The present invention provides a silicone rubber compound, a preparation method thereof and an application. The preparation method includes step S1: subjecting raw materials including methionine, o-phenylenediamine and tetraethyl orthosilicate to hydrothermal reaction, dialysis treatment and surface activation modification treatment in sequence to obtain active silicon-carbon quantum dots; step S2: ultrasonically dispersing the active silicon-carbon quantum dots in a raw rubber solution (a first raw rubber and toluene) to form a raw rubber / active silicon-carbon quantum dot dispersion liquid, and subjecting the dispersion liquid and excessive ethanol to flocculation, precipitation, etc. in sequence to obtain a silicon-carbon quantum dot masterbatch; step S3: mixing raw materials including the silicon-carbon quantum dot masterbatch, raw rubber, aluminum hydroxide, fumed silica, methyl silicone oil, hydroxyl silicone oil, trihydroxyethylamine, ultraviolet absorber and light stabilizer to obtain a raw material system; step S4: subjecting the raw material system to three-roll grinding treatment and other treatments in sequence to obtain a silicone rubber compound with excellent comprehensive properties such as ultraviolet aging resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer functional materials, and more particularly, to a silicone rubber masterbatch, a preparation method thereof, and an application thereof. Background Art

[0002] Silicone rubber composite insulators are widely used in high-altitude areas. The climatic conditions in these areas are extremely harsh, the air is thin, and more ultraviolet rays can pass through the atmosphere to reach the ground. The annual ultraviolet radiation dose is much higher than that in other areas. The external insulation performance of the composite insulator depends on the silicone rubber shed material. In the silicone rubber molecule, elements are combined by covalent bonds, and the bond force between elements is relatively weak. There are also a large number of carbon-hydrogen chemical bonds inside the material. Ultraviolet rays can cut the macromolecular chains of silicone rubber, and then oxidation, degradation, and cross-linking reactions occur, resulting in changes in the internal structure, leading to a decline in electrical and mechanical properties, and causing the phenomenon of accelerated aging of silicone rubber.

[0003] Since obvious ultraviolet aging phenomena will occur when the existing composite insulators operate in this environment for a long time, the external insulation material must have high requirements for ultraviolet aging resistance. In addition to ensuring excellent electrical insulation performance, it is also required to have the characteristic that the mechanical properties can be maintained for a long time under ultraviolet aging conditions, so as to have a longer service life and reduce the frequency of line maintenance and replacement.

[0004] Therefore, how to solve the above technical problems, develop a silicone rubber masterbatch material with excellent ultraviolet aging resistance, and realize the large-scale production and application of composite insulators with excellent ultraviolet aging resistance is an urgent technical problem to be solved by those skilled in the art. Summary of the Invention

[0005] The main object of the present invention is to provide a silicone rubber masterbatch, a preparation method thereof, and an application thereof, so as to solve the problem that the existing silicone rubber masterbatch has poor ultraviolet aging resistance, resulting in a short service life.

[0006] In order to achieve the above object, according to one aspect of the present invention, a method for preparing a silicone rubber compound is provided. The preparation method includes the following steps: Step S1, subjecting raw materials including methionine, o-phenylenediamine, and tetraethyl orthosilicate to hydrothermal reaction and dialysis treatment in sequence to obtain silicon-carbon quantum dots; after grinding the silicon-carbon quantum dots, performing surface activation modification treatment with an A-172 silane modifier to obtain activated carbon quantum dots. Step S2, mixing and dissolving the first raw rubber with toluene to obtain a raw rubber solution; ultrasonically dispersing the activated silicon-carbon quantum dots in the raw rubber solution to form a raw rubber / activated silicon-carbon quantum dot dispersion; subjecting the raw rubber / activated silicon-carbon quantum dot dispersion and excessive ethanol to flocculation, precipitation, filtration, and drying in sequence to obtain a silicon-carbon quantum dot masterbatch. Step S3, mixing raw materials including the silicon-carbon quantum dot masterbatch, raw rubber, aluminum hydroxide, fumed silica, methyl silicone oil, hydroxyl silicone oil, triethanolamine, ultraviolet absorber, and light stabilizer to obtain a raw material system. Step S4, subjecting the raw material system to three-roll grinding treatment, open mill treatment, and sulfur addition and coloring treatment in sequence to obtain a silicone rubber compound; wherein, by weight, the raw material system includes: 100 parts of raw rubber, 0.3 to 5 parts of activated carbon quantum dots, 100 to 140 parts of aluminum hydroxide, 25 to 50 parts of fumed silica, 2 to 8 parts of hydroxyl silicone oil, 2 to 6 parts of methyl silicone oil, 0.2 to 0.8 parts of triethanolamine, 0.5 to 3 parts of ultraviolet absorber, and 0.5 to 3 parts of light stabilizer.

[0007] Further, in the above step S1, the mass ratio of methionine, o-phenylenediamine, and tetraethyl orthosilicate is (2 to 4):(1 to 2):(1 to 2).

[0008] Further, in the above step S1, the solvent for the hydrothermal reaction is water, preferably deionized water; and / or the mass ratio of methionine to the volume of water is (2 to 4) g:(20 to 30) mL; and / or the temperature of the hydrothermal reaction is 150°C to 200°C, and the time of the hydrothermal reaction is 16 h to 24 h; and / or, at 25 to 30°C, subjecting the product after the hydrothermal reaction to dialysis in a dialysis bag, the dialysis time is 72 to 120 h, and then drying at 80°C for 8 to 12 h to obtain silicon-carbon quantum dots; and / or, the A-172 silane modifier is vinyltris(2-methoxyethoxy)silane.

[0009] Further, the above-mentioned step S3 includes: initially mixing raw materials including second raw rubber, aluminum hydroxide, fumed silica, methyl silicone oil, hydroxyl silicone oil, trihydroxyethylamine, ultraviolet absorber, and light stabilizer by using a kneader to obtain an initial mixture; mixing the initial mixture with a silicon carbide quantum dot masterbatch to obtain a raw material system; wherein, the total amount of the first raw rubber and the second raw rubber is the same as the amount of raw rubber in the raw material system; and / or, the ultraviolet absorber is a benzotriazole type, and / or, the ultraviolet absorber is 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole; and / or, the light stabilizer is a polymeric hindered amine light stabilizer, and / or, the light stabilizer is poly-{[6-[(1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl][2-(2,2,6,6-tetramethylpiperidinyl)-amino]-hexylene-[4-(2,2,6,6-tetramethylpiperidinyl)-imino]}, and / or, the number average molecular weight of poly-{[6-[(1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl][2-(2,2,6,6-tetramethylpiperidinyl)-amino]-hexylene-[4-(2,2,6,6-tetramethylpiperidinyl)-imino]} is 2000~3100; and / or, the aluminum hydroxide is activated aluminum hydroxide treated with an A-172 silane modifier, and the particle size of the aluminum hydroxide is 0.5 μm~5 μm; and / or the specific surface area of the fumed silica is 150 m 2 / g~300 m 2 / g.

[0010] Further, in the above-mentioned step S2, the mass ratio of the active silicon carbide quantum dots to the raw rubber in the silicon carbide quantum dot masterbatch is 1:4~1:10, and the ultrasonic dispersion time of the active silicon carbide quantum dots in the raw rubber solution is 30 min~60 min.

[0011] Further, the above-mentioned step S4 includes: after the raw material system is completed by mixing and kneading, vacuum pumping treatment, open mill treatment, and filtering treatment are successively carried out to obtain white rubber; the white rubber is successively subjected to three-roll grinding treatment, open mill treatment, and sulfur addition and color addition treatment to obtain a silicone rubber mixed rubber; and / or, the temperature of the vacuum pumping treatment is 120~170 °C, and the vacuum degree is ≤ -0.07 MPa.

[0012] Further, in the above step S4, a vulcanizing agent is added during the sulfur addition and coloring treatment. The vulcanizing agent is a two-component platinum-based vulcanizing agent, which is a combination of 0.5-2 parts by weight of component A platinum vulcanizing agent and 1-3.5 parts by weight of component B platinum vulcanizing agent; at a temperature of ≤45°C, component B platinum vulcanizing agent and component A platinum vulcanizing agent are sequentially added to the white glue; the effective platinum content in component A platinum vulcanizing agent is 10-25 wt%; component B platinum vulcanizing agent is a mixture of a delaying agent, raw rubber, and silica, and the effective content of the delaying agent is 5-15 wt%.

[0013] According to another aspect of the present invention, a silicone rubber masterbatch is provided, which is prepared by the foregoing method for preparing a silicone rubber masterbatch.

[0014] According to still another aspect of the present invention, a composite insulator is provided, and the composite insulator includes the foregoing silicone rubber masterbatch.

[0015] Applying the technical solution of the present invention, the present application provides the above preparation method for using a special silicon-carbon quantum dot masterbatch to prepare a silicone rubber masterbatch. Since the silicon-carbon quantum dots contain carbon-silicon bonds in their chemical structure, the preparation method with active treatment can achieve good dispersion in the silicone rubber and has good compatibility with the silicone rubber, thus obtaining a silicone rubber masterbatch with excellent comprehensive performance. In addition, an ultraviolet absorber and a light stabilizer are added during the preparation of the masterbatch. Utilizing the characteristic that the ultraviolet absorber can absorb ultraviolet light in the wavelength range of 280-360 nm and convert the light energy into heat energy, combined with the characteristic that the light stabilizer terminates the continued reaction of the chain segments damaged by ultraviolet light, the multi-substance synergistic effect improves the anti-ultraviolet aging performance of the silicone rubber masterbatch, making the silicone rubber masterbatch have excellent ultraviolet aging resistance. In addition, the present application creatively selects a two-component platinum vulcanization system, which enables the silicone rubber to be fully cross-linked in the first vulcanization, eliminates the need for secondary vulcanization, has a low molding temperature, a fast vulcanization speed, and obvious energy-saving and consumption-reducing advantages; simultaneously breaks the conventional requirement of the silicone rubber industry for using a peroxide-initiated vulcanization system, solves the industry problem of the silicone rubber using a hindered amine light stabilizer that cannot be catalyzed by the peroxide system, and the preparation method is simple in operation, low in production cost, and suitable for large-scale production applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The schematic diagrams in the specification, which form a part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 Shows the preparation flow chart of the silicone rubber masterbatch in the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0019] As analyzed in the background art of the present application, there is a problem in the prior art that the silicone rubber compound has poor ultraviolet aging resistance, resulting in a short lifespan. To solve the above problems, the present application provides a silicone rubber compound and its preparation method and application.

[0020] In a typical embodiment of the present application, a preparation method of a silicone rubber compound is provided. As Figure 1 shown, the preparation method includes the following steps: Step S1, subjecting the raw materials including methionine, o-phenylenediamine, and tetraethyl orthosilicate to hydrothermal reaction and dialysis treatment in sequence to obtain silicon-carbon quantum dots; grinding the silicon-carbon quantum dots and then performing surface activation modification treatment with an A-172 silane modifier to obtain active silicon-carbon quantum dots; Step S2, mixing and dissolving the first raw rubber with toluene to obtain a raw rubber solution; ultrasonically dispersing the active silicon-carbon quantum dots in the raw rubber solution to form a raw rubber / active silicon-carbon quantum dot dispersion; subjecting the raw rubber / active silicon-carbon quantum dot dispersion and excessive ethanol to flocculation, precipitation, filtration, and drying in sequence to obtain a silicon-carbon quantum dot masterbatch; Step S3, mixing the raw materials including the silicon-carbon quantum dot masterbatch, raw rubber, aluminum hydroxide, fumed silica, methyl silicone oil, hydroxyl silicone oil, triethanolamine, ultraviolet absorber, and light stabilizer to obtain a raw material system; Step S4, subjecting the raw material system to three-roll grinding treatment, open mill treatment, and sulfur addition and color addition treatment in sequence to obtain a silicone rubber compound; wherein, by weight, the raw material system includes 100 parts of raw rubber, 0.3 to 2 parts of active silicon-carbon quantum dots, 100 to 140 parts of aluminum hydroxide, 25 to 50 parts of fumed silica, 2 to 8 parts of hydroxyl silicone oil, 2 to 6 parts of methyl silicone oil, 0.2 to 0.8 parts of triethanolamine, 0.5 to 3 parts of ultraviolet absorber, and 0.5 to 3 parts of light stabilizer.

[0021] This application provides a method for preparing the above-mentioned silicone rubber masterbatch using a special silicon-carbon quantum dot masterbatch. Due to the presence of carbon-silicon bonds in the chemical structure of the silicon-carbon quantum dots, a preparation method involving active treatment can achieve good dispersion in silicone rubber and good compatibility with silicone rubber, thereby obtaining a silicone rubber masterbatch with excellent comprehensive properties. In addition, an ultraviolet absorber and a light stabilizer are added during the preparation of the masterbatch. Utilizing the property that the ultraviolet absorber can absorb ultraviolet light in the wavelength range of 280-360 nm and convert the light energy into heat energy, combined with the property of the light stabilizer to terminate the continued reaction of the chain segments damaged by ultraviolet light, the multi-substance synergistic effect improves the anti-ultraviolet aging performance of the silicone rubber masterbatch, making the silicone rubber masterbatch have excellent ultraviolet aging resistance. In addition, this application creatively selects a two-component platinum vulcanization system, which enables sufficient primary vulcanization crosslinking of the silicone rubber, eliminates the need for secondary vulcanization, has a low molding temperature, a fast vulcanization speed, and obvious energy-saving and consumption-reducing advantages; simultaneously breaks the conventional requirements of the silicone rubber industry for using a peroxide-initiated vulcanization system, solves the industry problem of the use of silicone rubber where hindered amine light stabilizers cannot be catalyzed by the peroxide system, and this preparation method is simple to operate and has a low production cost, suitable for large-scale production applications.

[0022] In one embodiment of the present application, in the above step S1, the mass ratio of methionine, o-phenylenediamine, and tetraethyl orthosilicate is (2-4):(1-2):(1-2).

[0023] By controlling the mass ratio of methionine, o-phenylenediamine, and tetraethyl orthosilicate within the above range, it helps to improve the comprehensive properties such as the compatibility of the prepared silicon-carbon quantum dots, thereby obtaining a silicone rubber masterbatch with excellent comprehensive properties.

[0024] In one embodiment of the present application, in the above step S1, the solvent for the hydrothermal reaction is water, preferably deionized water; and / or the mass ratio of methionine to the volume of water is (2-4) g:(20-30) mL; and / or the temperature of the hydrothermal reaction is 150°C - 200°C, and the time of the hydrothermal reaction is 16 h - 24 h; and / or, at 25 - 30°C, the product after the hydrothermal reaction is dialyzed in a dialysis bag for 72 - 120 h, and then dried at 80 o °C for 8 - 12 h to obtain silicon-carbon quantum dots; and / or, the A-172 silane modifier is vinyltris(2-methoxyethoxy)silane.

[0025] In this application, water is selected as the solvent. Since water is a polar molecule, most substances can be partially dissolved in water, which is beneficial to promoting the diffusion and migration of solutes. Moreover, water is cheap, easily available, environmentally friendly and pollution-free. Deionized water is preferably used as the solvent because deionized water contains almost no impurities, which can avoid the influence of impurities in the solvent on the performance of silicon-carbon quantum dots. The preferred hydrothermal reaction conditions help the raw materials to react fully, improving the utilization rate of raw materials while ensuring the performance of carbon quantum dots.

[0026] Controlling the hydrothermal reaction conditions helps to convert the liquid carbon compound into solid carbon dots under high temperature and high pressure. Controlling the dialysis conditions helps for more thorough dialysis.

[0027] In addition, grinding the silicon-carbon quantum dots into fine powder and adding vinyltris(2-methoxyethoxy)silane as the A-172 silane modifier for surface activation treatment to obtain active silicon-carbon quantum dots helps for the full dispersion of silicon-carbon quantum dots in silicone rubber.

[0028] In an embodiment of this application, in the above step S1, dialysis treatment is carried out using a dialysis membrane, and / or the cut-off molecular weight of the dialysis membrane is 200 Da - 300 Da, and / or the dialysis treatment time is 72 - 120 h.

[0029] Preferably, the cut-off molecular weight of the dialysis membrane is within the above range, which helps to obtain carbon quantum dots with a uniform particle size distribution. At the same time, by controlling the dialysis treatment time within the above range, it helps to improve the efficiency and effect of dialysis, thereby helping to improve the comprehensive performance of the silicone rubber compound. In addition, in this application, the dialysis membrane is not particularly limited and can be a commonly used dialysis membrane in the art, which will not be elaborated here.

[0030] In an embodiment of the present application, the above step S3 includes: initially mixing raw materials including a second raw rubber, aluminum hydroxide, fumed silica, methyl silicone oil, hydroxy silicone oil, trihydroxyethylamine, an ultraviolet absorber, and a light stabilizer using a kneader to obtain an initial mixture; mixing the initial mixture with a silicon carbon quantum dot masterbatch to obtain a raw material system; wherein the total amount of the first raw rubber and the second raw rubber is the same as the amount of the raw rubber in the raw material system; and / or, the ultraviolet absorber is a benzotriazole type, and / or, the ultraviolet absorber is 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole; and / or, the light stabilizer is a polymeric hindered amine light stabilizer, and / or, the light stabilizer is poly-{[6-[(1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl] [2-(2,2,6,6-tetramethylpiperidinyl)-amino]-hexylene-[4-(2,2,6,6-tetramethylpiperidinyl)-imino]}, and / or, the number average molecular weight of poly-{[6-[(1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl] [2-(2,2,6,6-tetramethylpiperidinyl)-amino]-hexylene-[4-(2,2,6,6-tetramethylpiperidinyl)-imino]} is 2000~3100; and / or, the aluminum hydroxide is activated aluminum hydroxide treated with an A-172 silane modifier, and the particle size of the aluminum hydroxide is 0.5μm~5μm; and / or the specific surface area of the fumed silica is 150m 2 / g~300m 2 / g.

[0031] The above step-by-step mixing helps to fully disperse the raw materials in the raw rubber; the selection of the types of the ultraviolet absorber and the light stabilizer helps to absorb ultraviolet light in the range of 280~360mm in wavelength, convert the light energy into heat energy, and capture the broken free radical bonds and react with them to finally terminate the continuous destruction of the long chain.

[0032] In addition, by controlling the particle size of the aluminum hydroxide within the above range, it is beneficial to make the aluminum hydroxide fully contact with other components in the raw materials, improve the reaction efficiency and effect, and thus help to improve the comprehensive performance of the silicone rubber compound. By controlling the specific surface area of the fumed silica within the above range, it helps to improve the full contact between the fumed silica and other components in the raw materials, thereby improving the reaction efficiency and effect, and further helping to improve the comprehensive performance of the silicone rubber compound.

[0033] In an embodiment of the present application, in the above step S2, the mass ratio of the active silicon carbon quantum dots to the raw rubber in the silicon carbon quantum dot masterbatch is 1:4~1:10; the ultrasonic dispersion time of the active silicon carbon quantum dots in the raw rubber solution is 30 min~60min.

[0034] Step S2 carried out through the above distribution makes the raw material system more uniform. By controlling the mass ratio of silicon-carbon quantum dots to raw rubber within the above range, it helps to improve the uniform dispersion of silicon-carbon quantum dots in raw rubber, and thus improve the performance of silicone rubber masterbatch. Controlling the conditions of ultrasonic dispersion helps the silicon-carbon quantum dots to be fully dispersed in the raw rubber solution.

[0035] In an embodiment of the present application, the above step S4 includes: after the raw material system is completed by mixing, vacuum treatment, open mill treatment and filtering treatment are carried out in sequence to obtain white glue; the white glue is subjected to three-roll grinding treatment, open mill treatment and sulfur addition and color addition treatment in sequence to obtain silicone rubber masterbatch; and / or, the temperature of the vacuum treatment is 120~170 °C, and the vacuum degree is ≤ -0.07 MPa.

[0036] The above treatments help to remove small molecule substances and impurities in the white glue, and ensure that powders, oils, additives, etc. are fully dispersed and penetrated in the raw rubber.

[0037] In an embodiment of the present application, by weight, in the above step S4, during the sulfur addition and color addition treatment, a vulcanizing agent is added. The vulcanizing agent is a two-component platinum system vulcanizing agent, which is a combination of 0.5~2 parts by weight of component A platinum vulcanizing agent and 1~3.5 parts by weight of component B platinum vulcanizing agent; at a temperature of ≤ 45 °C, component B platinum vulcanizing agent and component A platinum vulcanizing agent are added to the white glue in sequence; the effective platinum content in component A platinum vulcanizing agent is 10~25 wt%; component B platinum vulcanizing agent is a mixture of a delay agent, raw rubber and silica, and the effective content of the delay agent is 5~15 wt%.

[0038] The present application further optimizes the mass fraction and type of the vulcanizing agent during the sulfur addition and color addition treatment, which helps to further improve the comprehensive performance of the silicone rubber masterbatch.

[0039] The two-component platinum system vulcanizing agent helps the raw rubber filled with fillers such as aluminum hydroxide, fumed silica, and ultraviolet absorber to be fully vulcanized and crosslinked.

[0040] At a temperature of ≤ 45 °C, component B platinum vulcanizing agent and component A platinum vulcanizing agent are added to the white glue in sequence. Such an addition sequence helps the vulcanizing agent to be fully absorbed by the rubber compound and prevents the phenomenon of "dead rubber" during the sulfur addition process.

[0041] Controlling the effective platinum content in component A platinum vulcanizing agent to be 10~25 wt% helps to control the risk and ensure safe storage during the preparation process of the vulcanizing agent.

[0042] The effective content of the B-component platinum vulcanizing agent as a delaying agent is 5-15 wt%, which helps to control the addition ratio and the safe reaction of silicone rubber, and prevents "dead rubber" caused by premature scorching; preferably, the type of the delaying agent is a mixture of hydrogen-containing substances and 1-ethynylcyclohexanol.

[0043] Preferably, a color paste is further added during the sulfur addition and color addition treatment. Preferably, the color paste is an iron red color paste prepared by mixing ferric oxide with raw rubber.

[0044] Preferably, the vulcanization molding temperature of the silicone rubber masterbatch prepared by the above steps is 130-150 °C, and the vulcanization time is determined according to the product structure.

[0045] The injection molding process of the high-temperature vulcanized silicone rubber masterbatch prepared by the platinum vulcanization system is smokeless and odorless, and the vulcanization temperature is 130-150 °C, which is much lower than the vulcanization temperature of 160-170 °C of the silicone rubber masterbatch catalyzed by peroxide initiators. Therefore, the platinum vulcanization system of the present application is more energy-saving and consumption-reducing and has better environmental performance.

[0046] In another typical embodiment of the present application, a silicone rubber masterbatch is provided, and the silicone rubber masterbatch is prepared by the aforementioned preparation method.

[0047] The present application provides a silicone rubber masterbatch, which is prepared by using the above-mentioned preparation method of the silicone rubber masterbatch. The silicone rubber masterbatch has well-dispersed silicon carbon quantum dots and good compatibility with silicone rubber. Therefore, its comprehensive performance is excellent, especially its ultraviolet aging resistance performance is excellent, and it is suitable for large-scale production applications.

[0048] In yet another typical embodiment of the present application, a composite insulator is provided, and the composite insulator includes the aforementioned silicone rubber masterbatch.

[0049] The composite insulator provided by the present application has excellent ultraviolet aging resistance performance, has a long service life in high-altitude and high-altitude areas, and has broad application prospects.

[0050] The beneficial effects of the present application will be further described below in conjunction with embodiments.

[0051] Example 1

[0052] Refer to Figure 1 The preparation flow chart of the silicone rubber masterbatch shown is used to prepare the silicone rubber masterbatch, which is specifically as follows:

[0053] 1) Dissolve methionine, o-phenylenediamine and tetraethyl orthosilicate in 20 mL of deionized water, and perform ultrasonic treatment for 30 min to obtain an ultrasonicated solution;

[0054] 2) Perform hydrothermal reaction and dialysis treatment on the ultrasonicated solution for 5 days, and dry to obtain silicon carbon quantum dots;

[0055] Among them, in the dialysis treatment, a dialysis membrane with a molecular weight cut-off of 200 Da is used for dialysis treatment;

[0056] The mass-volume ratio of methionine, o-phenylenediamine, tetraethyl orthosilicate and deionized water is 2 g: 1 g: 1 g: 20 mL;

[0057] The temperature of the hydrothermal reaction is 180 °C and the time is 12 h;

[0058] 3) Dissolve the first raw rubber (methyl vinyl silicone rubber) and toluene in a toluene solvent according to a mass ratio of 1:10, then ultrasonically disperse the silicon carbon quantum dots in the raw rubber solution for 30 min to form a silicon carbon quantum dot dispersion liquid. Add excessive ethanol for flocculation and precipitation, and then perform filtration treatment and drying to obtain a precipitate of raw rubber / silicon carbon quantum dot masterbatch (raw rubber / CDs masterbatch);

[0059] Among them, the mass ratio of silicon carbon quantum dots to raw rubber in the raw rubber / silicon carbon quantum dot masterbatch is 1:9.

[0060] 4) Mix the raw materials of silicon carbon quantum dot masterbatch, raw rubber, aluminum hydroxide, fumed silica, methyl silicone oil, hydroxy silicone oil, triethanolamine, ultraviolet absorber and light stabilizer to obtain a raw material system;

[0061] In the raw material system, the mass parts of each material are 1.3 parts of active silicon carbon quantum dots, 100 parts of raw rubber, 100 parts of aluminum hydroxide, 27 parts of fumed silica, 5 parts of methyl silicone oil, 3 parts of hydroxy silicone oil, 0.5 part of triethanolamine, 1.5 parts of ultraviolet absorber, and 1.5 parts of light stabilizer; among them, in the raw material system, the mass fraction of silicon carbon quantum dots is 0.5 wt%, the particle size of aluminum hydroxide is 3 μm, and the specific surface area of fumed silica is 200 m 2 / g.

[0062] 5) Perform three-roll grinding treatment, open mill treatment and sulfur addition and color addition treatment on the raw material system to obtain a silicone rubber mixed rubber;

[0063] Among them, during the open mill treatment, the roll gap of the open mill is ≤5 mm and the number of times is ≥2 times;

[0064] In the sulfur addition and color addition treatment, the vulcanizing agent is a two-component platinum-based vulcanizing agent. The added mass part of component A platinum-based vulcanizing agent is 1.2 parts, and the added mass part of component B platinum-based vulcanizing agent is 2.6 parts.

[0065] Example 2

[0066] The difference from Example 1 is that in 4), the raw materials of silicon carbide quantum dot masterbatch, raw rubber, aluminum hydroxide, fumed silica, methyl silicone oil, hydroxy silicone oil, triethanolamine, ultraviolet absorber and light stabilizer are mixed to obtain a raw material system;

[0067] In the raw material system, the mass parts of each material are 3.7 parts of active silicon carbide quantum dots, 100 parts of raw rubber, 100 parts of aluminum hydroxide, 27 parts of fumed silica, 5 parts of methyl silicone oil, 3 parts of hydroxy silicone oil, 0.5 part of triethanolamine, 1.5 parts of ultraviolet absorber, and 1.5 parts of light stabilizer; among them, in the mixed rubber, the mass fraction of silicon carbide quantum dots is 1.5 wt%, and finally a silicone rubber mixed rubber is obtained.

[0068] Example 3

[0069] The difference from Example 1 is that in 2), the mass-volume ratio of methionine, o-phenylenediamine, tetraethyl orthosilicate and deionized water is 3 g: 1 g: 1 g: 25 mL, and finally a silicone rubber mixed rubber is obtained.

[0070] Example 4

[0071] The difference from Example 1 is that in 2), the mass-volume ratio of methionine, o-phenylenediamine, tetraethyl orthosilicate and deionized water is 4 g: 2 g: 2 g: 30 mL, and finally a silicone rubber mixed rubber is obtained.

[0072] Example 5

[0073] The difference from Example 1 is that in 2), the mass-volume ratio of methionine, o-phenylenediamine, tetraethyl orthosilicate and deionized water is 1 g: 2.5 g: 2.5 g: 30 mL, and finally a silicone rubber mixed rubber is obtained.

[0074] Example 6

[0075] The difference from Example 1 is that in 2), the temperature of the hydrothermal reaction is 160 °C and the time is 24 h, and finally a silicone rubber mixed rubber is obtained.

[0076] Example 7

[0077] The difference from Example 1 is that in 4), the particle size of aluminum hydroxide is 1 μm, and finally a silicone rubber mixed rubber is obtained.

[0078] Example 8

[0079] The difference from Example 1 is that in 4), the specific surface area of fumed silica is 300 m 2 / g, and finally a silicone rubber mixed rubber is obtained.

[0080] Comparative Example 1

[0081] 1) Mix the raw materials of raw rubber, aluminum hydroxide, fumed silica, methyl silicone oil, hydroxy silicone oil, and triethanolamine to obtain a raw material system;

[0082] In the raw material system, the mass parts of each material are 100 parts of raw rubber, 100 parts of aluminum hydroxide, 27 parts of fumed silica, 5 parts of methyl silicone oil, 3 parts of hydroxy silicone oil, and 0.5 part of triethanolamine.

[0083] 2) Conduct open mill treatment and sulfur addition and color addition treatment on the raw material system to obtain silicone rubber mixed rubber;

[0084] Among them, during the open mill treatment, the roll gap of the open mill is ≤5 mm, and the number of times is ≥2 times;

[0085] In the sulfur addition and color addition treatment, the vulcanizing agent is 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and the added mass part of the vulcanizing agent is 1.5 parts.

[0086] Comparative Example 2

[0087] The difference from Example 1 is that carbon quantum dots are prepared by the preparation method in the patent application document with the application number 202311735262.8, and an equal amount of carbon quantum dots is used to replace the silicon carbon quantum dots in Example 1, and finally silicone rubber mixed rubber is obtained.

[0088] Comparative Example 3

[0089] The difference from Example 1 is that no ultraviolet absorber is added, and finally silicone rubber mixed rubber is obtained.

[0090] Comparative Example 4

[0091] The difference from Example 1 is that no light stabilizer is added, and finally silicone rubber mixed rubber is obtained.

[0092] Performance Test

[0093] Conduct mechanical tests on the silicone rubber mixed rubber in the examples and comparative examples respectively, specifically including:

[0094] Carry out aging tests on the standard tensile splines of silicone rubber mixed rubber in an ultraviolet aging oven at a wavelength of 340 nm for different times, the aging temperature is 85 °C, and then conduct ultraviolet aging experiments according to the times of 0 h, 24 h, 48 h, 96 h, 120 h, and 192 h. Conduct mechanical tests on the aged splines respectively: Place dumbbell-shaped tensile splines with dimensions of 75×4×2 mm on a universal material tensile machine for tensile performance testing, the test temperature is room temperature, and the tensile rate is 500 mm / min. Test 5 splines in each group, and then take their average value.

[0095] The silicone rubber masterbatches prepared in the above-mentioned examples and comparative examples were subjected to tensile property tests. The tensile strengths of the silicone rubber masterbatches prepared in the above-mentioned examples and comparative examples were measured at 0 h, 24 h, 48 h, 96 h, 120 h, and 192 h respectively. The results are shown in Table 1.

[0096] Table 1 Tensile Strengths of Silicone Rubber Masterbatches at Different Aging Times

[0097]

[0098] The silicone rubber masterbatches prepared in the above-mentioned examples and comparative examples were subjected to tensile property tests. The elongation at break of the silicone rubber masterbatches prepared in the above-mentioned examples and comparative examples were measured at 0 h, 24 h, 48 h, 96 h, 120 h, and 192 h respectively. The results are shown in Table 2.

[0099] Table 2 Elongation at Break of Silicone Rubber Masterbatches at Different Aging Times

[0100]

[0101] Table 1 shows the tensile strength data of the silicone rubber masterbatches in Examples 1-8 and Comparative Examples 1-4 of the present invention; Table 2 shows the elongation at break data of the silicone rubber masterbatches in Examples 1-8 and Comparative Examples 1-4 of the present invention. It can be seen from Table 1 that with the increase of aging time, the attenuation of the tensile strength of the silicone rubber masterbatches in the examples of the present invention is slower. It can be seen from Table 2 that the elongation at break of the silicone rubber masterbatches in Examples 1-8 of the present invention is significantly better than that of the silicone rubber masterbatches in Comparative Examples 1-4. Therefore, the addition of silicon carbon quantum dots can inhibit the decline of the mechanical properties of silicone rubber under ultraviolet aging. This is because the silicon carbon quantum dots in the silicone rubber masterbatch of the example have an absorption peak near the 340 nm ultraviolet region, and due to their good compatibility with silicone rubber, they can be better dispersed in the silicone, so they can efficiently absorb ultraviolet rays, prevent the ultraviolet aging of the silicone rubber masterbatch, and then can significantly prevent the decrease of the elongation at break of the silicone rubber masterbatch under ultraviolet aging conditions without a significant decrease in tensile strength, which has a promoting effect on the anti-aging of the silicone rubber masterbatch. The carbon quantum dots used in Comparative Example 2 have a weaker interaction with the silicone rubber raw rubber than the silicon quantum dots, so after being added to the silicone rubber, its tensile strength and elongation at break are lower than those of the silicon carbon quantum dot system with the same content, and the degree of decrease in tensile strength and elongation at break after ultraviolet aging is faster, and its anti-ultraviolet aging effect on the silicone rubber masterbatch is weaker than that of the examples of the present application.

[0102] From the above description, it can be seen that the above-mentioned examples of the present invention achieve the following technical effects:

[0103] This application provides a preparation method as above, which uses a special silicon-carbon quantum dot masterbatch to prepare a silicone rubber compound. Due to the carbon-silicon bond in the chemical structure of the silicon-carbon quantum dots, a preparation method combined with active treatment can achieve good dispersion in the silicone rubber, and at the same time has good compatibility with the silicone rubber, thus obtaining a silicone rubber compound with excellent comprehensive performance. In addition, an ultraviolet absorber and a light stabilizer are added during the preparation of the compound. By utilizing the characteristic that the ultraviolet absorber can absorb ultraviolet light in the wavelength range of 280-360nm and convert the light energy into heat energy, combined with the characteristic that the light stabilizer terminates the continuous reaction of the chain segments damaged by ultraviolet light, the multi-substance synergistic effect improves the anti-ultraviolet aging performance of the silicone rubber compound, making the silicone rubber compound have excellent ultraviolet aging resistance. In addition, this application creatively selects a two-component platinum vulcanization system, which enables the silicone rubber to be fully cross-linked in the first vulcanization, without the need for secondary vulcanization, and has a low molding temperature, a fast vulcanization speed, and obvious advantages in energy conservation and consumption reduction; at the same time, it breaks the conventional requirements of the silicone rubber industry for using a peroxide-initiated vulcanization system, solves the industry problem of the silicone rubber using a hindered amine light stabilizer that cannot be catalyzed by the peroxide system, and this preparation method is simple to operate, has a low production cost, and is suitable for large-scale production applications.

[0104] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a silicone rubber masterbatch, characterized in that, The preparation method includes the following steps: Step S1: Subject the raw materials including methionine, o-phenylenediamine, and tetraethyl orthosilicate to hydrothermal reaction and dialysis treatment in sequence to obtain silicon-carbon quantum dots; grind the silicon-carbon quantum dots and perform surface activation modification treatment with A-172 silane modifier to obtain active silicon-carbon quantum dots; Step S2: Mix and dissolve the first raw rubber with toluene to obtain a raw rubber solution; ultrasonically disperse the active silicon-carbon quantum dots in the raw rubber solution to form a raw rubber / active silicon-carbon quantum dot dispersion; subject the raw rubber / active silicon-carbon quantum dot dispersion and excessive ethanol to flocculation, precipitation, filtration, and drying in sequence to obtain a silicon-carbon quantum dot masterbatch; Step S3: Use a kneader to preliminarily mix raw materials including second raw rubber, aluminum hydroxide, fumed silica, methyl silicone oil, hydroxyl silicone oil, trihydroxyethylamine, ultraviolet absorber, and light stabilizer to obtain a preliminary mixture; mix the preliminary mixture with the silicon carbon quantum dot masterbatch to obtain a raw material system; wherein, the total amount of the first raw rubber and the second raw rubber is the same as the amount of the raw rubber in the raw material system; the ultraviolet absorber is a benzotriazole type, and the ultraviolet absorber is 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole; the light stabilizer is a polymeric hindered amine light stabilizer, and the light stabilizer is poly-{[6-[(1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl] [2-(2,2,6,6-tetramethylpiperidinyl)-amino]-hexylene-[4-(2,2,6,6-tetramethylpiperidinyl)-imino]}, and the number average molecular weight of the poly-{[6-[(1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl] [2-(2,2,6,6-tetramethylpiperidinyl)-amino]-hexylene-[4-(2,2,6,6-tetramethylpiperidinyl)-imino]} is 2000~3100; the aluminum hydroxide is activated aluminum hydroxide treated with A-172 silane modifier, and the particle size of the aluminum hydroxide is 0.5μm~5μm; the specific surface area of the fumed silica is 150m 2 / g~300m 2 / g; Step S4: Subject the raw material system to three-roll grinding treatment, open mill treatment, and sulfur addition and color addition treatment in sequence to obtain the silicone rubber compound; Wherein, by weight parts, the raw material system includes: 100 parts of the raw rubber; 0.3 - 5 parts of the active silicon-carbon quantum dots; 100 - 140 parts of aluminum hydroxide; 25 - 50 parts of fumed silica; 2 - 8 parts of hydroxyl silicone oil; 2 - 6 parts of methyl silicone oil; 0.2 - 0.8 parts of triethanolamine; 0.5 - 3 parts of ultraviolet absorber; 0.5 - 3 parts of light stabilizer.

2. The preparation method according to claim 1, characterized in that, In the step S1, the mass ratio of methionine, o-phenylenediamine, and tetraethyl orthosilicate is (2 - 4):(1 - 2):(1 - 2).

3. The preparation method according to claim 1 or 2, characterized in that, In the step S1, the solvent for the hydrothermal reaction is water; and / or the mass ratio of methionine to the volume of water is (2-4) g:(20-30) mL; and / or the temperature of the hydrothermal reaction is 150°C to 200°C, and the time of the hydrothermal reaction is 16 h to 24 h; and / or, at 25-30°C, the product after the hydrothermal reaction is dialyzed in a dialysis bag for 72-120 h, and then dried at 80 o °C for 8-12 h to obtain the silicon carbon quantum dots; And / or, the A-172 silane modifier is vinyltris(2-methoxyethoxy)silane.

4. The preparation method according to claim 1 or 2, characterized in that, In the step S1, a dialysis membrane is used for the dialysis treatment, and / or the cut-off molecular weight of the dialysis membrane is 200 Da - 300 Da, and / or the time of the dialysis treatment is 72 - 120 h.

5. The preparation method according to claim 1 or 2, characterized in that, In the step S2, the mass ratio of the active silicon-carbon quantum dots to the raw rubber in the silicon-carbon quantum dot masterbatch is 1:4 - 1:10; the ultrasonic dispersion time of the active silicon-carbon quantum dots in the raw rubber solution is 30 min - 60 min.

6. The preparation method according to claim 1 or 2, characterized in that, The step S4 includes: After the raw material system is kneaded, perform vacuum pumping treatment, open mill treatment, and filtering treatment in a kneader in sequence to obtain white rubber; Subject the white rubber to three-roll grinding treatment, open mill treatment, and sulfur addition and color addition treatment in sequence to obtain the silicone rubber compound; And / or, the temperature of the vacuum pumping treatment is 120 - 170 °C, and the vacuum degree is ≤ -0.07 MPa.

7. The preparation method according to claim 6, characterized in that, By weight parts, in the step S4, a vulcanizing agent is added during the sulfur addition and color addition treatment, the vulcanizing agent is a two-component platinum-based vulcanizing agent, and the vulcanizing agent is a combination of 0.5 - 2 parts by weight of component A platinum vulcanizing agent and 1 - 3.5 parts by weight of component B platinum vulcanizing agent; At a temperature of ≤ 45 °C, add component B platinum vulcanizing agent and component A platinum vulcanizing agent to the white rubber in sequence; The effective platinum content in the component A platinum vulcanizing agent is 10 - 25 wt%; The component B platinum vulcanizing agent is a mixture of a retarder, raw rubber, and silica, and the effective content of the retarder is 5 - 15 wt%.

8. A silicone rubber compound, characterized in that, Prepared by the preparation method of the silicone rubber compound according to any one of claims 1 to 7.

9. A composite insulator, characterized in that, The composite insulator comprises the silicone rubber compound of claim 8.

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