Insulating coating on the side of a lightning arrester resistor disc and method for producing the same

Abstract

The application discloses an insulating coating on the side of a lightning arrester resistor sheet and a preparation method thereof, and belongs to the technical field of lightning arrester manufacturing. The method comprises the following steps: mixing SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene and a defoaming agent, and stirring to obtain a coating; coating a coupling agent on the side of the resistor sheet, and obtaining a to-be-sprayed resistor sheet after shade drying; spraying the coating on the side of the to-be-sprayed resistor sheet, and obtaining a sprayed resistor sheet; and performing solidification treatment on the sprayed resistor sheet, and completing the preparation of the insulating coating on the side of the resistor sheet. The application dopes tributyl phosphate as a defoaming agent, guarantees the spraying quality of the glue solution, and thus improves the insulating performance. The nano-alumina is doped, and the insulating performance and the high-temperature resistance are further improved. Vinyl tri-tert-butyl peroxysilane is used as the coupling agent, is uniformly coated on the side of the resistor sheet, and the bonding strength between the silicone rubber and the resistor sheet is increased.

Description

Technical Field

[0001] This invention belongs to the field of surge arrester manufacturing technology, and relates to an insulating coating on the side of a surge arrester resistor element and its preparation method. Background Technology

[0002] Surge arresters, as crucial protective devices in power systems, play a key role in protecting electrical equipment from damage caused by lightning overvoltages. Lightning overvoltages possess extremely high voltage amplitudes and immense energy; once they intrude into electrical equipment, they can easily cause insulation breakdown, equipment damage, and even serious accidents such as fires and explosions, severely threatening the safe and stable operation of the power system. Surge arresters can quickly guide the overvoltage to the ground when a lightning overvoltage strikes, thereby effectively protecting electrical equipment.

[0003] ZnO varistors are the core components of surge arresters, and their performance directly affects the arrester's effectiveness. ZnO varistors possess unique nonlinear volt-ampere characteristics, exhibiting a high-resistance state under normal operating voltage and conducting almost no current. When encountering lightning overvoltage, they quickly transition to a low-resistance state, absorbing and dissipating the overvoltage energy. After the overvoltage dissipates, they automatically return to the high-resistance state, continuing their protective function. However, insufficient lateral insulation of the ZnO varistor during use can lead to a decrease in the surge arrester's performance or even its failure. Therefore, improving the lateral insulation of ZnO varistors is a pressing issue in surge arrester manufacturing technology.

[0004] In existing technologies, to improve the side insulation of ZnO varistors, an inorganic high-resistivity layer combined with an epoxy resin insulating coating is often used. However, this method has significant drawbacks.

[0005] Firstly, the inorganic high-resistivity layer with epoxy resin insulating coating exhibits poor stability under thermal shock conditions. During surge arrester operation, due to the thermal effect of current and changes in ambient temperature, the resistor element and insulating coating may suffer thermal shock. At this time, the bonding force between the epoxy resin insulating coating and the resistor element will significantly weaken, leading to separation and detachment of the epoxy resin insulating coating from the resistor element. After the insulating coating detaches, the side of the ZnO varistor element is directly exposed, resulting in a significant decrease in insulation performance and a severe weakening of the surge arrester's protective function.

[0006] Secondly, the epoxy resin insulating coating has poor high-temperature resistance. When the ambient temperature exceeds 150℃, the epoxy resin insulating coating is prone to carbonization. Carbonization drastically reduces the insulation performance of the coating, making it unable to effectively prevent current leakage from the sides of the resistor element, severely impacting the side insulation capability. Under some special operating conditions, the internal temperature of the surge arrester may exceed 150℃, which greatly limits the application of epoxy resin insulating coatings.

[0007] Therefore, how to improve the high-temperature resistance and adhesion of the side insulating coating to the resistor sheet is an urgent problem to be solved in the field of side insulating coating preparation technology. Summary of the Invention

[0008] The purpose of this invention is to provide an insulating coating on the side of a surge arrester resistor and its preparation method, so as to solve the technical problems of easy peeling and failure of the insulating coating at high temperature in the prior art.

[0009] To achieve the above objectives, the present invention employs the following technical solution:

[0010] In a first aspect, the present invention provides a method for preparing an insulating coating on the side of a surge arrester resistor element, comprising the following steps:

[0011] SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene, and defoamer are mixed and stirred to obtain a coating.

[0012] A coupling agent is coated on the side of the resistor sheet, and after air drying, the resistor sheet to be sprayed is obtained.

[0013] The coating is applied to the side of the resistor sheet to be coated, resulting in a coated resistor sheet.

[0014] The coated resistor sheet is cured to complete the preparation of the insulating coating on the side of the resistor sheet.

[0015] Furthermore, the defoamer is tributyl phosphate.

[0016] Furthermore, the mass ratio of the SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene mixture and tributyl phosphate is 50:(1~10):(10~30):(1-10):(0.0001~0.001).

[0017] Furthermore, the coupling agent is vinyltritert-butylperoxysilane.

[0018] Furthermore, the stirring time is 1 hour.

[0019] Furthermore, the step of spraying the coating onto the side of the resistor sheet to obtain the coated resistor sheet specifically includes: loading the coating into the spray gun, adjusting the spray gun to a preset pressure and a preset angle, and then spraying the coating onto the side of the resistor sheet.

[0020] Furthermore, the preset pressure is 0.4 MPa to 0.6 MPa; the preset angle is 90°.

[0021] Furthermore, the curing process is as follows: the coated resistor sheet is placed in an oven and cured at 150°C for 2 hours.

[0022] Furthermore, it also includes: after curing, the resistor sheet is subjected to a grinding and aluminum spraying process.

[0023] Secondly, the present invention provides an insulating coating on the side of a surge arrester resistor element, which is prepared by the method described above for preparing an insulating coating on the side of a surge arrester resistor element.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention discloses an insulating coating for the side of a surge arrester resistor element and its preparation method. By doping SiC rubber with nano-alumina, the strength of the coating adhesive is improved, making it easier to spray. Furthermore, the doping with nano-alumina enhances the insulation and high-temperature resistance of the resistor element. By changing the matrix material used for the side insulation, the high-temperature resistance and insulation performance of the resistor element's side can be significantly improved, enabling it to withstand high thermal stress. Using vinyltriterpenoid peroxysilane as a coupling agent, it is uniformly coated onto the side of the resistor element, increasing the bonding strength between the silicone rubber and the resistor element, thereby extending the service life of the surge arrester. The side insulating resin prepared by this invention possesses high insulation performance and excellent elasticity, capable of resisting the impact of high electric and thermal stresses. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart illustrating a method for preparing an insulating coating on the side of a surge arrester resistor element according to the present invention. Detailed Implementation

[0028] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0029] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0030] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0031] In this article, unless otherwise specified, the terms “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of”. For example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a”.

[0032] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0033] The present invention will now be described in further detail with reference to the accompanying drawings:

[0034] See Figure 1 This invention discloses a method for preparing an insulating coating on the side of a surge arrester resistor element, specifically including the following steps:

[0035] S1, SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene and defoamer are mixed and stirred to obtain a coating;

[0036] In this step, the mass ratio of the SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene mixture and tributyl phosphate added is 50:(1~10):(10~30):(1-10):(0.0001~0.001).

[0037] The defoamer is preferably tributyl phosphate. The stirring time is 1 hour.

[0038] S2, A coupling agent is coated on the side of the resistor sheet, and after air drying, the resistor sheet to be sprayed is obtained.

[0039] In this step, the coupling agent is preferably vinyltritert-butylperoxysilane.

[0040] S3, Use paint to spray the side of the resistor sheet to be coated to obtain the coated resistor sheet;

[0041] The paint is loaded into the spray gun, and after adjusting the spray gun to the preset pressure and preset angle, the paint is sprayed onto the side of the resistor element. The preset pressure is 0.4 MPa ~ 0.6 MPa; the preset angle is 90°.

[0042] S4. The sprayed resistor sheet is cured to complete the preparation of the insulating coating on the side of the resistor sheet.

[0043] In this step, the curing process is as follows: the coated resistor sheet is placed in an oven and cured at 150°C for 2 hours.

[0044] S5. After curing, the resistor sheet is removed and subjected to a grinding and aluminum spraying process. After completion, performance testing can be performed.

[0045] This invention discloses an insulating coating on the side of a resistor sheet prepared by the above method. The invention uses vinyltriterpenoid peroxysilane as a coupling agent, which is uniformly coated onto the side of the resistor sheet to increase the bonding strength between the SiC rubber and the resistor sheet. Tributyl phosphate is used as a defoamer to eliminate air bubbles in the adhesive, ensuring the quality of the adhesive spraying and thus improving the insulation performance. The use of doped nano-alumina improves the insulation performance and high-temperature resistance, increases the adhesive strength, and improves the spraying effect.

[0046] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0047] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0048] Example 1:

[0049] Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano alumina, and toluene, add a small amount of tributyl phosphate, pour into a mixing tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano alumina, toluene and tributyl phosphate is 50:5:20:5:0.0005.

[0050] Step 2: Apply vinyltributylperoxysilane coupling agent to the side of the resistor sheet and allow it to air dry to obtain the resistor sheet to be sprayed for later use.

[0051] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.4 MPa and the angle to 90°, and spray the side of the resistor to obtain the coated resistor.

[0052] Step 4: Place the coated resistor sheet in an oven and cure it at 150°C for 2 hours.

[0053] Step 5: After curing, the resistor sheet is removed and subjected to a grinding and aluminum spraying process, followed by testing. The test results show that the lateral insulation and high-temperature resistance of the resistor sheet are significantly improved.

[0054] Example 2:

[0055] Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano alumina, and toluene, add a small amount of tributyl phosphate, pour into a mixing tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano alumina, toluene and tributyl phosphate is 50:2:25:2:0.0003.

[0056] Step 2: Apply vinyltributylperoxysilane coupling agent to the side of the resistor sheet and allow it to air dry to obtain the resistor sheet to be sprayed for later use.

[0057] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.5 MPa and the angle to 90°, and spray the side of the resistor to obtain the coated resistor.

[0058] Step 4: Place the coated resistor sheet in an oven and cure it at 150°C for 2 hours.

[0059] Step 5: After curing, the resistor sheet is removed and subjected to a grinding and aluminum spraying process, followed by testing. The test results show that the lateral insulation and high-temperature resistance of the resistor sheet are significantly improved.

[0060] Example 3:

[0061] Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano alumina, and toluene, add a small amount of tributyl phosphate, pour into a mixing tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano alumina, toluene and tributyl phosphate is 50:8:30:8:0.0007.

[0062] Step 2: Apply vinyltributylperoxysilane coupling agent to the side of the resistor sheet and allow it to air dry to obtain the resistor sheet to be sprayed for later use.

[0063] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.6 MPa and the angle to 90°, and spray the side of the resistor to obtain the coated resistor.

[0064] Step 4: Place the coated resistor sheet in an oven and cure it at 150°C for 2 hours.

[0065] Step 5: After curing, the resistor sheet is removed and subjected to a grinding and aluminum spraying process, followed by testing. The test results show that the lateral insulation and high-temperature resistance of the resistor sheet are significantly improved.

[0066] The resistive sheets with insulating coatings prepared in the above three embodiments were subjected to high-temperature resistance tests, capacitance tests, and high-current tests. The test results are shown in Table 1 below.

[0067] Table 1 Test results of Examples 1-3

[0068]

[0069] Example 4:

[0070] Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano alumina, and toluene, add a small amount of tributyl phosphate, pour into a mixing tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano alumina, toluene and tributyl phosphate is 50:4:15:4:0.0004.

[0071] Step 2: Apply vinyltributylperoxysilane coupling agent to the side of the resistor sheet and allow it to air dry to obtain the resistor sheet to be sprayed for later use.

[0072] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.5 MPa and the angle to 90°, and spray the side of the resistor to obtain the coated resistor.

[0073] Step 4: Place the coated resistor sheet in an oven and cure it at 150°C for 2 hours.

[0074] Step 5: After curing, the resistor sheet is removed and subjected to a grinding and aluminum spraying process, followed by testing. The test results show that the lateral insulation and high-temperature resistance of the resistor sheet are significantly improved.

[0075] Example 5:

[0076] Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano alumina, and toluene, add a small amount of tributyl phosphate, pour into a mixing tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano alumina, toluene and tributyl phosphate is 50:7:10:7:0.0001.

[0077] Step 2: Apply vinyltributylperoxysilane coupling agent to the side of the resistor sheet and allow it to air dry to obtain the resistor sheet to be sprayed for later use.

[0078] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.4 MPa and the angle to 90°, and spray the side of the resistor to obtain the coated resistor.

[0079] Step 4: Place the coated resistor sheet in an oven and cure it at 150°C for 2 hours.

[0080] Step 5: After curing, the resistor sheet is removed and subjected to a grinding and aluminum spraying process, followed by testing. The test results show that the lateral insulation and high-temperature resistance of the resistor sheet are significantly improved.

[0081] This invention improves the strength of the coating adhesive by doping SiC rubber with nano-alumina, making it easier to spray. Furthermore, the doping with nano-alumina enhances the insulation and high-temperature resistance of the resistor element. By changing the matrix material used for the side insulation, the high-temperature resistance and insulation performance of the resistor element's side surface can be significantly improved, enabling it to withstand high thermal stress and thus extending the service life of the surge arrester. The side insulation resin prepared by this invention possesses high insulation performance and excellent elasticity, capable of resisting the impact of high electric and thermal stresses. Therefore, it has wide applications in surge arrester manufacturing, resistor element manufacturing, and ceramic insulation materials. The side insulation coating technology for surge arrester resistor elements of this invention significantly improves the insulation performance and high-temperature resistance of the resistor element, thereby enhancing the protective effect of the surge arrester and meeting the high standards required by power systems for surge arresters. Therefore, this invention has broad market application prospects and demand.

[0082] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of preparing an insulating coating on the side of a surge arrester resistor disc, characterized by, It comprises the following steps: Mixing SiC rubber, ethyl silicate, nano-alumina, toluene and defoaming agent to obtain a coating by stirring; the defoaming agent is tributyl phosphate; the coupling agent is vinyl tri-tert-butyl peroxide silane; the adding mass ratio of SiC rubber, ethyl silicate, nano-alumina, toluene and tributyl phosphate is 50: (1-10): (10-30): (1-10): (0.0001-0.001); Coating a layer of coupling agent on the side of the resistance sheet, and obtaining the resistance sheet to be sprayed after drying; Spraying the coating on the side of the resistance sheet to be sprayed to obtain a sprayed resistance sheet; Curing the sprayed resistance sheet to complete the preparation of the side insulation coating of the resistance sheet; the curing process is that the sprayed resistance sheet is placed in an oven and cured at a temperature of 150 DEG C for 2h.

2. The method of claim 1, wherein the insulating coating is prepared by applying a solution of a polymer to the side of the arrester resistor sheet. The stirring time is 1h.

3. The method of claim 1, wherein the insulating coating is prepared by applying a solution of a polymer to the side of the arrester resistor sheet. The step of spraying the coating on the side of the resistance sheet to be sprayed to obtain a sprayed resistance sheet comprises the following steps: loading the coating into a spray gun, adjusting the spray gun to a preset pressure and a preset angle, and then spraying the side of the resistance sheet.

4. The method of claim 3, wherein the insulating coating is prepared by applying a solution of a polymer to the side of the arrester resistor sheet. The preset pressure is 0.4Mpa-0.6Mpa; the preset angle is 90 DEG.

5. The method of claim 1, wherein the insulating coating is prepared by applying a solution of a polymer to the side of the arrester resistor sheet. It also comprises: After the curing is completed, the resistance sheet is subjected to a grinding and aluminum spraying process.

6. An insulating coating on the side of a surge arrester resistor, characterized by The side insulation coating of the resistance sheet of the lightning arrester is prepared by the preparation method of any one of claims 1-5.

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