Flame-retardant ceramic voltage-resistant silica gel composite material and preparation method thereof

Abstract

The invention relates to a flame-retardant ceramic voltage-resistant silica gel composite material and a preparation method thereof, and the flame-retardant ceramic voltage-resistant silica gel composite material comprises the following components in parts by weight: polysiloxane; a flame retardant enhancing component; a modified pressure-resistant ceramic component; a wear-resistant reinforcing component; polytetrafluoroethylene resin; a lubricating rheological agent; the modified pressure-resistant ceramic component is obtained by pretreating tin oxide particles with a low-density high polymer material and ethyl acetate; and preferably, the tin oxide particles are selected from tin oxide particles with micron-sized particle sizes; the flame-retardant ceramic voltage-resistant silica gel composite material prepared according to the process disclosed by the invention has an improved voltage-resistant characteristic while maintaining good mechanical properties.

Description

Technical Field

[0001] This invention relates to a composite material related to silicone (silicone rubber, organosilicon) and its preparation method, specifically to a flame-retardant ceramicized voltage-resistant silicone composite material and its preparation method. Background Technology

[0002] With the rapid development of industries such as energy storage materials and new energy vehicles, the application and demand for insulating voltage-resistant materials are increasing across various sectors. These industries not only require silicone or rubber insulating materials to have good heat resistance, but also good resistance to electrical breakdown under high-voltage conditions.

[0003] Various studies have been conducted on the voltage withstand properties of related composite materials. For example, Chinese Patent Publication CN116376432A discloses a ceramic-coated mica tape with a coating, which contains silicone and related ceramic components, such as mica. However, such studies have not comprehensively investigated the mechanical properties and voltage breakdown characteristics of silicone composite materials, and multilayered materials are not conducive to large-scale production and reducing production costs.

[0004] Therefore, there are still areas for improvement in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a flame-retardant ceramicized voltage-resistant silicone (organic silicone, silicone rubber) composite material and its preparation method. The composite material prepared according to the process of this invention can achieve both good mechanical properties and voltage breakdown resistance.

[0006] According to a first aspect of the present invention, a method for preparing a flame-retardant ceramicized voltage-resistant silicone composite material is provided, wherein, calculated according to their respective weight parts, the flame-retardant ceramicized voltage-resistant silicone composite material comprises the following raw material components:

[0007] Polysiloxane alkyl content: 120-300 parts by weight;

[0008] Flame retardant reinforcing component: 5-15 parts by weight;

[0009] Modified pressure-resistant ceramic component: 10-30 parts by weight;

[0010] 5-30 parts by weight of wear-resistant reinforcing component;

[0011] Polytetrafluoroethylene resin: 5-30 parts by weight;

[0012] Lubricating rheology modifier: 10-30 parts by weight; and

[0013] The modified pressure-resistant ceramic component is a modified pressure-resistant ceramic component obtained by pretreatment of tin oxide particles with low-density polymer materials and ethyl acetate; and preferably, the tin oxide particles are selected to have a particle size of micrometers.

[0014] In a preferred embodiment, the modified pressure-resistant ceramic component is obtained by the following method:

[0015] Micron-sized tin oxide, linear low-density polyethylene resin, and ethyl acetate were thoroughly mixed in a mixer. The temperature of the mixing system was controlled at 50°C to 60°C, and the stirring speed was 300-400 rpm for 30-60 minutes. Then the stirring was stopped, and the mixture was allowed to stand until it reached room temperature to obtain the modified pressure-resistant ceramic component.

[0016] In a further preferred embodiment, the flame-retardant reinforcing component is prepared from magnesium hydroxide, linear low-density polyethylene resin, and ethyl acetate through a mixing and stirring process.

[0017] In a further preferred embodiment, the method includes the following processes and steps:

[0018] Prepare each ingredient according to the ingredient ratio;

[0019] Preparation steps of polysiloxane alkyl component: wherein the polysiloxane alkyl component comprises 10wt%-15wt% of terminal epoxy silicone oil with a molecular weight of 6000 to 9000, 50wt%-60wt% of bifunctional phenyl vinyl silicone oil with a molecular weight of 1500 to 2500, 10wt%-20wt% of bifunctional phenyl hydrogen silicone oil with a molecular weight of 1000 to 1300, 1wt% of regulating component (1-ethynyl-1-cyclohexanol), and the remaining mass percentage is diluted and mixed with ethyl acetate; the above components are thoroughly mixed in a mixer to obtain the polysiloxane alkyl component;

[0020] Preparation steps of flame retardant reinforcing component: The flame retardant reinforcing component is composed of magnesium hydroxide, linear low-density polyethylene resin and ethyl acetate in a mass ratio of (20-30wt%):(40-50wt%):(10-20wt%), and the combination of the above three raw materials is 100wt%; wherein, the above three raw materials are thoroughly mixed in a mixer, maintaining an inert atmosphere (such as nitrogen), and controlling the system temperature at 50℃ to 60℃, stirring at 300-400rpm for 30-60 minutes, then stopping stirring, standing until room temperature for later use;

[0021] Next, take 20 parts by weight of deionized water, add the weighed flame-retardant reinforcing component to the deionized water and stir. The stirring speed is controlled at 400-500 rpm and the stirring time is 30-45 minutes. Then, add 5 wt% tetraethyl orthosilicate and 10 wt% heptadecafluorodecyltrimethoxysilane, which account for 5 wt% of the total solid content of the flame-retardant reinforcing component. Stir thoroughly again, but at a lower speed than before, for example, controlled at 150-200 rpm and the stirring time is controlled at 60 to 120 minutes. The flame-retardant reinforcing component is obtained.

[0022] Preparation steps of modified pressure-resistant ceramic component: Take micron-sized tin oxide (D50 average particle size of 10-20 microns), and mix it with tin oxide linear low-density polyethylene resin and ethyl acetate in a mass ratio of (30-40wt%):(40-50wt%):(10-20wt%), with the total percentage of the three raw materials being 100wt%. Mix the above three raw materials thoroughly in a mixer, control the temperature of the mixing system at 50℃ to 60℃, and the stirring speed at 300-400rpm for 30-60 minutes. Then stop stirring, let it stand until it reaches room temperature to obtain the modified pressure-resistant ceramic component for later use.

[0023] The polysiloxane alkyl component, the prepared flame-retardant reinforcing component, and the modified pressure-resistant ceramic component are mixed according to the weight ratio. The wear-resistant reinforcing component, which is selected as quartz fiber with a diameter of about 10-50 micrometers, is added. After thorough stirring, a preliminary mixture is obtained.

[0024] Add the appropriate proportion of polytetrafluoroethylene resin powder to the obtained preliminary mixture, and then mix to obtain a secondary mixture;

[0025] The secondary mixture is mixed with the catalyst component, and ethyl acetate is added again as a lubricating rheology modifier. Then, the flame-retardant ceramicized voltage-resistant silicone is placed in a container of a corresponding shape and cured at room temperature to obtain the material. The catalyst component is selected from tetrabutyltitanium. According to the weight parts of each component of the flame-retardant ceramicized voltage-resistant silicone, the catalyst component is selected from 0.5 to 1 part by weight.

[0026] In a second aspect, the present invention provides a flame-retardant ceramicized voltage-resistant silicone composite material, characterized in that the flame-retardant ceramicized voltage-resistant silicone composite material is prepared by any one of the methods described above.

[0027] In the typical flame-retardant ceramicized high-voltage silicone composite material prepared in this invention, the withstand voltage test result of the flame-retardant ceramicized high-voltage silicone composite material is greater than or equal to 40KV / mm.

[0028] The silicone (organic silicone) composite material of the present invention has good mechanical properties and fire resistance.

[0029] The technical solutions and advantages of the present invention will be explained and described in more detail below with reference to specific embodiments. It should be understood that the content presented in the specification and specific embodiments is only for the purpose of more clearly illustrating the technical solutions and advantages of the present invention, and does not constitute a limitation on the scope of protection of the present invention. Those skilled in the art can obtain various reasonable modifications based on the disclosure in the specification, and as long as they do not depart from the spirit of the present invention, all modified technical solutions should be understood to be included within the scope of protection of the present invention. Attached Figure Description

[0030] The accompanying drawings are provided to further understand the technical solutions of this disclosure and constitute a part of the specification. They are used together with the specific embodiments of this application to explain the technical solutions of this disclosure and do not constitute a limitation on the technical solutions of this disclosure.

[0031] Figure 1 This is a photographic schematic diagram of the sheet-like flame-retardant ceramicized voltage-resistant silicone composite material prepared according to Example 1 of the present invention;

[0032] Figure 2 This is a cross-sectional SEM scanning electron microscope image of the flame-retardant ceramicized voltage-resistant silicone composite material manufactured according to Example 1 after undergoing a pressure resistance test. Detailed Implementation

[0033] The invention is described in more detail below to aid in understanding it.

[0034] Before describing the specific implementation scheme, it should be noted that those skilled in the art can select appropriate raw materials based on the teachings and guidance of this disclosure, conduct relevant tests using relevant testing equipment, and obtain corresponding results. For raw materials for which specific manufacturers or methods are not specified, those skilled in the art can select raw materials that meet the corresponding requirements as reaction starting materials based on the disclosure and needs of this specification. The reaction raw materials for the compounds in the process section are derived from the initial products synthesized in the preceding steps of this invention, which is also understandable based on this disclosure.

[0035] First, Table 1 lists the main raw materials used in this invention and their corresponding acquisition channels or origins. It should be noted that any raw materials not specified in this invention are those that can be obtained by those skilled in the art based on ordinary technical knowledge and existing market products.

[0036] Table 1: Description of the main raw materials used in this invention

[0037]

[0038] It should be noted that percentages in the technical solutions, embodiments, and contents of this invention are generally described in detail. Unless otherwise specified, concentrations or percentages refer to mass percentages (wt%), or parts related to mass and related proportions.

[0039] In addition, the present invention may use open-ended component definition such as "comprising" or "including". However, in a preferred embodiment, the method and product of the present invention may consist only of the components defined in the present invention, without necessarily including any other components.

[0040] Test experiments of the present invention

[0041] In this experimental example, thermal conductivity was tested according to ASTM D5470; heat resistance was assessed using wind tunnel testing (JGJ / T 338-2014) with reference to the relevant testing procedures. During the experiment, a high-temperature airflow was used to apply a thermal load to the silicone material covering the embodiments of this invention or comparative embodiments, equivalent to 390 kW of heat energy passing through each square meter of the ceramic silicone composite material and the workpiece (e.g., chips, engineering components, cables, etc.). This test simulated the heat resistance performance of the workpiece and the composite silicone material under harsh thermal environments. Regarding the back surface parameters, under high-temperature thermal loads, it was confirmed whether the silicone composite material could maintain the temperature of the back surface of the workpiece or target component in a high heat flux density environment to meet the requirements of harsh operating conditions.

[0042] Regarding the mechanical strength of materials, tensile strength can be tested according to the national standard GB / T 34709-2017; while the compressive breakdown strength test can be conducted according to the national standard GB / T 1695-2005.

[0043] The following will describe in more detail the products prepared according to the embodiments of the present invention and their performance characterization.

[0044] Example 1

[0045] This embodiment will describe a typical method for preparing flame-retardant ceramicized voltage-resistant silicone and composite materials.

[0046] The raw materials for preparing the flame-retardant ceramicized voltage-resistant silicone of this embodiment typically include the following components:

[0047] Polysiloxane alkyl content: 180 parts by weight;

[0048] Flame retardant reinforcing component: 5 parts by weight;

[0049] Modified pressure-resistant ceramic component: 15 parts by weight;

[0050] Abrasion-resistant reinforcing component: 10 parts by weight;

[0051] Polytetrafluoroethylene resin: 15 parts by weight;

[0052] Lubricating rheology modifier: 25 parts by weight.

[0053] The polysiloxane alkyl component comprises (by weight percentage): 15 wt% of terminal epoxy-based silicone oil with a molecular weight (weight average molecular weight, the same below) of 6000 to 9000, 55 wt% of difunctional phenyl vinyl silicone oil with a molecular weight of 1500 to 2500, 20 wt% of difunctional phenyl hydrogen-containing silicone oil with a molecular weight of 1000-1300, 1 wt% of a regulating component (1-ethynyl-1-cyclohexanol), and the remaining mass percentage using ethyl acetate as a dilution and mixing component; the above components can be thoroughly mixed in a mixer to obtain the polysiloxane alkyl component.

[0054] Flame-retardant reinforcing component: The flame-retardant reinforcing component is composed of magnesium hydroxide, linear low-density polyethylene resin, and ethyl acetate in a mass ratio of 30wt%:50wt%:20wt%. The three raw materials are thoroughly mixed in a mixer under an inert atmosphere (such as nitrogen), and the system temperature is controlled at 50℃ to 60℃. The stirring speed is 300-400 rpm for 30-60 minutes, then stirring is stopped, and the mixture is allowed to stand until it reaches room temperature for later use.

[0055] Take 20 parts by weight of deionized water, add the weighed flame-retardant reinforcing component to the deionized water and stir. The stirring speed is controlled at 400-500 rpm and the stirring time is 30-45 minutes. Then, add 5 wt% tetraethyl orthosilicate and 10 wt% heptadecafluorodecyltrimethoxysilane, which account for 5 wt% of the total solid content of the flame-retardant reinforcing component. Stir thoroughly again, but at a lower speed than before, for example, controlled at 150-200 rpm and the stirring time is controlled at 60 to 120 minutes. The flame-retardant reinforcing component is obtained.

[0056] Modified pressure-resistant ceramic composition: Micron-sized tin oxide (D50 average particle size of 10-20 microns) is used, and tin oxide linear low-density polyethylene resin and ethyl acetate are mixed in a mass ratio of 40wt%:50wt%:10wt%. The three raw materials are thoroughly mixed in a mixer, the temperature of the mixing system is controlled at 50℃ to 60℃, the stirring speed is 300-400rpm, and the mixture is stirred for 30-60 minutes. Then the stirring is stopped, and the mixture is allowed to stand until it reaches room temperature for later use.

[0057] The polysiloxane alkyl component, the prepared flame-retardant reinforcing component, and the modified pressure-resistant ceramic component are mixed according to the weight ratio. The wear-resistant reinforcing component is then added, which is selected from quartz fibers with a diameter of about 30 micrometers and an aspect ratio greater than 20:1. After thorough stirring, a preliminary mixture is obtained.

[0058] Add the appropriate proportion of polytetrafluoroethylene resin powder to the obtained preliminary mixture, and then mix to obtain a secondary mixture;

[0059] The secondary mixture is mixed with the catalytic component (tetrabutyltitanium, calculated according to the weight parts of each component of the flame-retardant ceramicized voltage-resistant silicone, the catalytic component accounts for 0.5 to 1 part by weight), and then ethyl acetate is added again as a lubricating rheology agent according to the required scenario (e.g., the thickness of the cable or wire being coated). Then, in order to carry out relevant performance tests, the flame-retardant ceramicized voltage-resistant silicone can be placed in a container of appropriate shape and cured at room temperature to obtain the material.

[0060] In a typical preparation example, the prepared flame-retardant ceramicized voltage-resistant silicone is fabricated into rectangular sheet materials (e.g. Figure 1 As shown in the figure, it is suitable for conducting relevant pressure resistance tests and other test experiments.

[0061] Examples 2 to 4

[0062] The inventors made variations on the components in each embodiment within a certain range, and experimentally obtained the corresponding product of the embodiment:

[0063] Table 2: Raw material ratios for Examples 2 to 4

[0064]

[0065] Comparative Example 1

[0066] In Comparative Experiment 1, the raw material composition and related preparation process were basically the same as in Example 1. The difference was that, in the modified pressure-resistant ceramic composition, micron-sized tin oxide was not pretreated. Instead, 15 parts by weight of commercially available tin oxide powder with a similar particle size range were used directly, and the preparation process was similar to that of the other raw materials in Example 1.

[0067] Comparative Example 2

[0068] In Comparative Experiment 1, the same raw material components and related preparation processes as in Example 1 were used. The difference was that nano-sized tin oxide ceramic powder (D50 particle size range between 80-100 nm) was used in the modified pressure-resistant ceramic component, and the same pretreatment process and other preparation processes as in Example 1 were performed.

[0069] Experimental test and analysis results

[0070] Table 3: Test Results of Examples and Comparative Examples

[0071]

[0072] The inventors unexpectedly discovered that pretreatment of commonly used refractory materials (magnesium hydroxide) with relatively low molecular weight organic polymers, such as low-density polyethylene (LDPE), and other compatible lubricants resulted in excellent heat resistance and thermal conductivity. The inventors believe that a highly uniform heat-resistant site is formed between the low-density linear polymer (such as linear low-density polyethylene resin) and the heat-resistant refractory material, allowing it to maintain high mechanical properties even after high-temperature and tensile tests.

[0073] Furthermore, the inventors unexpectedly discovered that pretreatment of the micron-sized insulating material SnO with relatively low molecular weight organic polymers, such as low-density polyethylene (LDPE), and other compatible lubricants can yield additionally improved voltage withstand properties. The inventors specifically performed scanning electron microscopy characterization on the cross-section of the silicone ceramicized material prepared in Example 1 after voltage withstand testing (see [link to sample]). Figure 2 ).from Figure 2 It can be seen that the micron-sized tin oxide particles are embedded in the silicone (organic silicone) matrix in a relatively deep and even manner, and maintain good spacing between each other. This may be because the branches of low-density polyethylene (LDPE) maintain the distance between particles well during the mixing process, enhance the electrostatic resistance between them, and enable the micron-sized tin oxide particles to be well anchored and distributed.

[0074] In contrast, the inventors found that when a simplified process was used, i.e., without low-density polyethylene (LDPE) pretreatment, although the thermal conductivity and heat resistance were not significantly affected, the voltage withstand performance was inferior to the examples. The inventors speculate that this may be because the absence of the fixing effect and steric hindrance effect of the low-molecular-weight polymer leads to a decrease in the average barrier properties of the tin oxide particles. As the applied voltage increases, reaching several kilovolts, the fixed-position insulation properties of the tin oxide particles deteriorate.

[0075] The inventors also unexpectedly discovered that when using commonly used nano-tin oxide as an additive, the voltage withstand characteristics were not as good as in the previous examples. The inventors speculate that this may be because micron-sized particles themselves have a better steric hindrance effect, while nano-sized particles provide insufficient steric hindrance effect in the rubber matrix, making it easier for current to break down the nano-tin oxide matrix.

[0076] Based on the embodiments and technical content described in this specification, the present invention can provide at least the following technical solutions: Although this disclosure includes specific embodiments, it will be apparent to those skilled in the art that various substitutions or changes in form and detail can be made to these embodiments without departing from the inventive spirit and scope of the claims and their equivalents. The embodiments described herein should be considered illustrative only and not for limiting purposes. The description of features and aspects in each embodiment is considered applicable to similar features and aspects in other embodiments. Therefore, the scope of this disclosure should not be limited by the specific description, but rather by the technical solutions of the claims, and all variations within the scope of the claims and their equivalents are to be interpreted as included within the technical solutions of this disclosure.

Claims

1. A method for preparing a flame-retardant, ceramicized, voltage-resistant silicone composite material, characterized in that, The flame-retardant ceramicized voltage-resistant silicone composite material comprises the following raw material components according to their respective weight parts: Polysiloxane alkyl content: 120-300 parts by weight; Flame retardant reinforcing component: 5-15 parts by weight; Modified pressure-resistant ceramic component: 10-30 parts by weight; 5-30 parts by weight of wear-resistant reinforcing component; Polytetrafluoroethylene resin: 5-30 parts by weight; Lubricating rheology modifier: 10-30 parts by weight; and The modified pressure-resistant ceramic component is a modified pressure-resistant ceramic component obtained by pretreatment of tin oxide particles with low-density polymer materials and ethyl acetate; and preferably, the tin oxide particles are selected to have a particle size of micrometers.

2. The method for preparing the flame-retardant ceramicized voltage-resistant silicone composite material according to claim 1, wherein the modified voltage-resistant ceramic component is obtained by the following method: Micron-sized tin oxide, linear low-density polyethylene resin, and ethyl acetate were thoroughly mixed in a mixer. The temperature of the mixing system was controlled at 50°C to 60°C, and the stirring speed was 300-400 rpm for 30-60 minutes. Then the stirring was stopped, and the mixture was allowed to stand until it reached room temperature to obtain the modified pressure-resistant ceramic component.

3. The method for preparing the flame-retardant ceramicized voltage-resistant silicone composite material according to any one of claims 1 to 2, wherein, The flame-retardant reinforcing component is prepared by mixing and stirring magnesium hydroxide, linear low-density polyethylene resin, and ethyl acetate.

4. The method for preparing the flame-retardant ceramicized voltage-resistant silicone composite material according to any one of claims 1 to 3, wherein, The method includes the following processes and steps: Prepare each ingredient according to the ingredient ratio; Preparation steps of polysiloxane alkyl component: wherein the polysiloxane alkyl component comprises 10wt%-15wt% of terminal epoxy silicone oil with a molecular weight of 6000 to 9000, 50wt%-60wt% of bifunctional phenyl vinyl silicone oil with a molecular weight of 1500 to 2500, 10wt%-20wt% of bifunctional phenyl hydrogen silicone oil with a molecular weight of 1000 to 1300, 1wt% of regulating component (1-ethynyl-1-cyclohexanol), and the remaining mass percentage is diluted and mixed with ethyl acetate; the above components are thoroughly mixed in a mixer to obtain the polysiloxane alkyl component; Preparation steps of flame retardant reinforcing component: The flame retardant reinforcing component is composed of magnesium hydroxide, linear low-density polyethylene resin and ethyl acetate in a mass ratio of (20-30wt%):(40-50wt%):(10-20wt%), and the combination of the above three raw materials is 100wt%; wherein, the above three raw materials are thoroughly mixed in a mixer, maintaining an inert atmosphere (such as nitrogen), and controlling the system temperature at 50℃ to 60℃, stirring at 300-400rpm for 30-60 minutes, then stopping stirring, standing until room temperature for later use; Next, take 20 parts by weight of deionized water, add the weighed flame-retardant reinforcing component to the deionized water and stir. The stirring speed is controlled at 400-500 rpm and the stirring time is 30-45 minutes. Then, add 5 wt% tetraethyl orthosilicate and 10 wt% heptadecafluorodecyltrimethoxysilane, which account for 5 wt% of the total solid content of the flame-retardant reinforcing component. Stir thoroughly again, but at a lower speed than before, for example, controlled at 150-200 rpm and the stirring time is controlled at 60 to 120 minutes. The flame-retardant reinforcing component is obtained. Preparation steps of modified pressure-resistant ceramic component: Take micron-sized tin oxide (D50 average particle size of 10-20 microns), and mix it with tin oxide linear low-density polyethylene resin and ethyl acetate in a mass ratio of (30-40wt%):(40-50wt%):(10-20wt%), with the total percentage of the three raw materials being 100wt%. Mix the above three raw materials thoroughly in a mixer, control the temperature of the mixing system at 50℃ to 60℃, and the stirring speed at 300-400rpm for 30-60 minutes. Then stop stirring, let it stand until it reaches room temperature to obtain the modified pressure-resistant ceramic component for later use. The polysiloxane alkyl component, the prepared flame-retardant reinforcing component, and the modified pressure-resistant ceramic component are mixed according to the weight ratio. The wear-resistant reinforcing component, which is selected as quartz fiber with a diameter of about 10-50 micrometers, is added. After thorough stirring, a preliminary mixture is obtained. Add the appropriate proportion of polytetrafluoroethylene resin powder to the obtained preliminary mixture, and then mix to obtain a secondary mixture; The secondary mixture is mixed with the catalyst component, and ethyl acetate is added again as a lubricating rheology modifier. Then, the flame-retardant ceramicized voltage-resistant silicone is placed in a container of a corresponding shape and cured at room temperature to obtain the material. The catalyst component is selected from tetrabutyltitanium. According to the weight parts of each component of the flame-retardant ceramicized voltage-resistant silicone, the catalyst component is selected from 0.5 to 1 part by weight.

5. A flame-retardant, ceramicized, voltage-resistant silicone composite material, characterized in that, The flame-retardant ceramicized voltage-resistant silicone composite material is prepared by the method described in any one of claims 1 to 4.

6. The flame-retardant ceramicized voltage-resistant silicone composite material according to claim 5, wherein the voltage withstand test result of the flame-retardant ceramicized voltage-resistant silicone composite material is greater than or equal to 40KV / mm.

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