Insulating coating on side surface of resistor disc of lightning arrester and preparation method of insulating coating

Abstract

The invention discloses an insulating coating on the side surface of a resistor disc of a lightning arrester and a preparation method of the insulating coating, and belongs to the technical field of manufacturing of lightning arresters. The method comprises the following steps: mixing SiC rubber, tetraethoxysilane, nano aluminum oxide, toluene and a defoaming agent, and stirring to obtain a coating; coating the side surface of the resistor disc with a layer of coupling agent, and drying in the shade to obtain a to-be-sprayed resistor disc; the side face of the to-be-sprayed resistor disc is sprayed with a coating, and the sprayed resistor disc is obtained; and curing the sprayed resistor disc to complete the preparation of the insulating coating on the side surface of the resistor disc. According to the invention, tributyl phosphate is doped as a defoaming agent, so that the spraying quality of the glue solution is ensured, and the insulating property is improved. And nano aluminum oxide is doped, so that the insulating property and the high-temperature resistance are further improved. Vinyl tri-tert-butylperoxy silane is adopted as a coupling agent and is uniformly coated on the side surface of the resistor disc, so that the bonding strength of the silicon rubber and the resistor disc is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lightning arrester manufacturing, and relates to an insulating coating on the side of a lightning arrester resistor sheet and a preparation method thereof. Background Art

[0002] As a vital protective device in the power system, lightning arresters play a key role in protecting electrical equipment from damage caused by lightning overvoltage. Lightning overvoltage has extremely high voltage amplitude and powerful energy. Once it invades electrical equipment, it is very easy to cause insulation breakdown, equipment damage, and even fire, explosion and other serious accidents, which seriously threaten the safe and stable operation of the power system. Lightning arresters can quickly guide the overvoltage to the ground when lightning overvoltage strikes, thereby effectively protecting electrical equipment.

[0003] Among them, ZnO varistor is the core component of the arrester, and its performance directly affects the use effect of the arrester. ZnO varistor has a unique nonlinear volt-ampere characteristic. It is in a high-resistance state under normal working voltage and hardly conducts current. When encountering lightning overvoltage, it can quickly change to a low-resistance state, absorb and discharge overvoltage energy, and automatically return to a high-resistance state after the overvoltage disappears, and continue to play a protective role. However, during the use of ZnO varistor, if its side insulation is insufficient, it may cause the performance of the arrester to decline or even fail. Therefore, how to improve the side insulation of ZnO varistor is an urgent problem to be solved in the field of arrester manufacturing technology.

[0004] In the prior art, in order to improve the insulation of the side of the ZnO varistor sheet, a method of adding an inorganic high-resistance layer and an epoxy resin insulation coating is often used. However, this method has obvious defects.

[0005] First, the inorganic high-resistance layer plus epoxy resin insulation coating has poor stability under thermal shock environment. During the operation of the arrester, due to the thermal effect of the current and the change of the external ambient temperature, the resistor and the insulation coating may be subjected to thermal shock. At this time, the bonding force between the epoxy resin insulation coating and the resistor will be significantly weakened, causing the epoxy resin insulation coating to separate and fall off from the resistor. After the insulation coating falls off, the side of the ZnO varistor is directly exposed, the insulation performance is greatly reduced, and the protective effect of the arrester is seriously weakened.

[0006] Second, the high temperature resistance of epoxy resin insulation coating is poor. When the ambient temperature is higher than 150°C, epoxy resin insulation coating is prone to carbonization. The insulation performance of the carbonized insulation coating is sharply reduced, and it cannot effectively prevent the current from leaking from the side of the resistor, seriously affecting the side insulation capacity. Under some special operating conditions, the internal temperature of the arrester may exceed 150°C, which greatly limits the application of epoxy resin insulation coating.

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

[0008] The object of the present invention is to provide an insulating coating on the side of a lightning arrester resistor and a preparation method thereof, so as to solve the technical problems in the prior art that the insulating coating is easy to fall off and easy to fail at high temperature.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for preparing an insulating coating on the side of a lightning arrester resistor, comprising the following steps: SiC rubber, tetraethyl orthosilicate, nano-aluminum oxide, toluene and a defoaming agent are mixed and stirred to obtain a coating; A layer of coupling agent is coated on the side of the resistor, and after air drying, a resistor to be sprayed is obtained; Use paint to spray the side of the resistor to be sprayed to obtain a sprayed resistor; The sprayed resistor is cured to complete the preparation of the insulating coating on the side of the resistor.

[0010] Furthermore, the defoaming agent is tributyl phosphate.

[0011] 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).

[0012] Furthermore, the coupling agent is vinyl tri-tert-butyl peroxide silane.

[0013] Furthermore, the stirring time is 1 hour.

[0014] Furthermore, the step of spraying the coating on the side of the resistor to be sprayed to obtain the sprayed resistor specifically includes: 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 resistor.

[0015] Furthermore, the preset pressure is 0.4Mpa~0.6Mpa; the preset angle is 90°.

[0016] Furthermore, the curing process is as follows: placing the sprayed resistor sheet in an oven and curing it at a temperature of 150° C. for 2 hours.

[0017] Furthermore, the method further comprises: after the curing is completed, the resistor sheet is subjected to a grinding and aluminum spraying process.

[0018] In a second aspect, the present invention provides an insulating coating on the side of a lightning arrester resistor sheet, which is prepared by using the method for preparing the insulating coating on the side of a lightning arrester resistor sheet.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses an insulating coating on the side of a resistor sheet of a lightning arrester and a preparation method thereof. By doping nano-alumina into SiC rubber, the strength of the coating glue is improved, making it easier to spray, and doping with nano-alumina can improve the insulation performance and high temperature resistance of the resistor sheet. By changing the matrix material used for the side insulation, the high temperature resistance and insulation performance of the side of the resistor sheet can be significantly improved, so that it can withstand high thermal field stress; vinyl tri-tert-butyl peroxysilane is used as a coupling agent, which is evenly coated on the side of the resistor sheet to increase the bonding strength between the silicone rubber and the resistor sheet, thereby increasing the service life of the lightning arrester. The side insulating resin prepared by the present invention has high insulation performance and very excellent elasticity, and can resist the impact of high electric field and high thermal field stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 The present invention is a flow chart of a method for preparing an insulating coating on the side of a lightning arrester resistor. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0023] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0024] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0025] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0026] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings: See also Figure 1 The embodiment of the present invention discloses a method for preparing an insulating coating on the side of a lightning arrester resistor, which specifically comprises the following steps: S1, mixing SiC rubber, tetraethyl orthosilicate, nano-aluminum oxide, toluene and defoaming agent, and stirring to obtain a coating; In this step, 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).

[0028] The defoaming agent is preferably tributyl phosphate. The stirring time is 1 hour.

[0029] S2, coating a layer of coupling agent on the side of the resistor, and obtaining the resistor to be sprayed after drying in the shade; In this step, the coupling agent is preferably vinyl tri-tert-butyl peroxide silane S3, spraying the coating on the side of the resistor to be sprayed to obtain a sprayed resistor; Put the paint into the spray gun, adjust the spray gun to the preset pressure and preset angle, and then spray the side of the resistor. The preset pressure is 0.4Mpa ~ 0.6Mpa; the preset angle is 90°.

[0030] S4, curing the sprayed resistor sheet to complete the preparation of the insulating coating on the side of the resistor sheet.

[0031] In this step, the curing process is as follows: placing the sprayed resistor sheet in an oven and curing it at a temperature of 150° C. for 2 hours.

[0032] S5, after curing, take out the resistor sheet and carry out the grinding and aluminum spraying process, after which the performance test can be carried out.

[0033] The embodiment of the present invention discloses an insulating coating on the side of a resistor sheet prepared by the above method. The present invention uses vinyl tri-tert-butyl peroxysilane as a coupling agent, which is evenly coated on 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 defoaming agent to eliminate bubbles in the rubber material, ensure the quality of the glue spraying, and thus improve the insulation performance. Doped nano-alumina is used to improve the insulation performance and high temperature resistance, and the strength of the glue is increased to improve the spraying effect.

[0034] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0035] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0036] Embodiment 1: Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano-alumina and toluene, add a small amount of tributyl phosphate, pour into a stirring tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene mixture and tributyl phosphate is 50:5:20:5:0.0005.

[0037] Step 2: Apply vinyl tri-tert-butyl peroxy silane coupling agent on the side of the resistor, and after it is dried in the shade, the resistor to be sprayed is obtained for standby use.

[0038] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.4Mpa, the angle to 90°, and spray the side of the resistor to obtain a sprayed resistor.

[0039] Step 4: Place the sprayed resistor in an oven and cure at 150°C for 2 hours.

[0040] Step 5: After curing, take out the resistor and perform grinding and aluminum spraying. After completion, test it. The test results show that the side insulation and high temperature resistance of the resistor are significantly improved.

[0041] Embodiment 2: Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano-alumina and toluene, add a small amount of tributyl phosphate, pour into a stirring tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene mixture and tributyl phosphate is 50:2:25:2:0.0003.

[0042] Step 2: Apply vinyl tri-tert-butyl peroxy silane coupling agent on the side of the resistor, and after it is dried in the shade, the resistor to be sprayed is obtained for standby use.

[0043] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.5Mpa, the angle to 90°, and spray the side of the resistor to obtain a sprayed resistor.

[0044] Step 4: Place the sprayed resistor in an oven and cure at 150°C for 2 hours.

[0045] Step 5: After curing, take out the resistor and perform grinding and aluminum spraying. After completion, test. The test results show that the side insulation and high temperature resistance of the resistor are significantly improved.

[0046] Embodiment 3: Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano-alumina and toluene, add a small amount of tributyl phosphate, pour into a stirring tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene mixture and tributyl phosphate is 50:8:30:8:0.0007.

[0047] Step 2: Apply vinyl tri-tert-butyl peroxy silane coupling agent on the side of the resistor, and after it is dried in the shade, the resistor to be sprayed is obtained for standby use.

[0048] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.6Mpa, the angle to 90°, and spray the side of the resistor to obtain a sprayed resistor.

[0049] Step 4: Place the sprayed resistor in an oven and cure at 150°C for 2 hours.

[0050] Step 5: After curing, take out the resistor and perform grinding and aluminum spraying. After completion, test. The test results show that the side insulation and high temperature resistance of the resistor are significantly improved.

[0051] The resistor sheets with insulating coatings prepared in the above three embodiments were subjected to side high temperature resistance test, capacity test and high current test. The test results are shown in Table 1 below.

[0052] Table 1 Test results of Examples 1 to 3

[0053] Embodiment 4: Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano-alumina and toluene, add a small amount of tributyl phosphate, pour into a stirring tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene mixture and tributyl phosphate is 50:4:15:4:0.0004.

[0054] Step 2: Apply vinyl tri-tert-butyl peroxy silane coupling agent on the side of the resistor, and after it is dried in the shade, the resistor to be sprayed is obtained for standby use.

[0055] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.5Mpa, the angle to 90°, and spray the side of the resistor to obtain a sprayed resistor.

[0056] Step 4: Place the sprayed resistor in an oven and cure at 150°C for 2 hours.

[0057] Step 5: After curing, take out the resistor and perform grinding and aluminum spraying. After completion, test. The test results show that the side insulation and high temperature resistance of the resistor are significantly improved.

[0058] Embodiment 5: Step 1: Mix SiC rubber, tetraethyl orthosilicate, nano-alumina and toluene, add a small amount of tributyl phosphate, pour into a stirring tank and stir for 1 hour to obtain a coating; wherein the mass ratio of SiC rubber, tetraethyl orthosilicate, nano-alumina, toluene mixture and tributyl phosphate is 50:7:10:7:0.0001.

[0059] Step 2: Apply vinyl tri-tert-butyl peroxy silane coupling agent on the side of the resistor, and after it is dried in the shade, the resistor to be sprayed is obtained for standby use.

[0060] Step 3: Load the paint into the spray gun, adjust the spray gun pressure to 0.4Mpa, the angle to 90°, and spray the side of the resistor to obtain a sprayed resistor.

[0061] Step 4: Place the sprayed resistor in an oven and cure at 150°C for 2 hours.

[0062] Step 5: After curing, take out the resistor and perform grinding and aluminum spraying. After completion, test. The test results show that the side insulation and high temperature resistance of the resistor are significantly improved.

[0063] The present invention improves the strength of the coating glue by doping nano-alumina in SiC rubber, making it easier to spray, and doping with nano-alumina can improve the insulation performance and high temperature resistance of the resistor. By changing the matrix material used for the side insulation, the high temperature resistance and insulation performance of the side of the resistor can be significantly improved, so that it can withstand high thermal field stress, thereby increasing the service life of the arrester. The side insulation resin prepared by the present invention has high insulation performance and very excellent elasticity, and can resist the impact of high electric field and high thermal field stress. Therefore, it can be widely used in the application fields of arrester manufacturing, resistor manufacturing, and ceramic insulation materials. The side insulation coating technology of the resistor for the arrester of the present invention can significantly improve the insulation performance and high temperature resistance of the resistor, thereby improving the protection effect of the arrester and meeting the high standard requirements of the power system for the arrester. Therefore, the present invention has broad market application prospects and needs.

[0064] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing an insulating coating on the side of a lightning arrester resistor, characterized in that: The following steps are involved: SiC rubber, tetraethyl orthosilicate, nano-aluminum oxide, toluene and a defoaming agent are mixed and stirred to obtain a coating; A layer of coupling agent is coated on the side of the resistor, and after air drying, a resistor to be sprayed is obtained; Use paint to spray the side of the resistor to be sprayed to obtain a sprayed resistor; The sprayed resistor is cured to complete the preparation of the insulating coating on the side of the resistor.

2. The method for preparing the insulating coating on the side of the arrester resistor according to claim 1, characterized in that: The defoaming agent is tributyl phosphate.

3. The method for preparing the insulating coating on the side of the arrester resistor according to claim 2, characterized in that: 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).

4. The method for preparing the insulating coating on the side of the arrester resistor according to claim 1, characterized in that: The coupling agent is vinyl tri-tert-butyl peroxide silane.

5. The method for preparing the insulating coating on the side of the arrester resistor according to claim 1, characterized in that: The stirring time is 1 h.

6. The method for preparing the insulating coating on the side of the arrester resistor according to claim 1, characterized in that: The step of spraying the coating on the side of the resistor to be sprayed to obtain the sprayed resistor specifically includes: 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 resistor.

7. The method for preparing the insulating coating on the side of the arrester resistor according to claim 6, characterized in that: The preset pressure is 0.4Mpa~0.6Mpa; the preset angle is 90°.

8. The method for preparing the insulating coating on the side of the arrester resistor according to claim 1, characterized in that: The curing process is as follows: placing the sprayed resistor in an oven and curing at 150° C. for 2 hours.

9. The method for preparing the insulating coating on the side of the arrester resistor according to claim 1, characterized in that: Also includes: After curing, the resistor is ground and aluminum sprayed.

10. An insulating coating on the side of a lightning arrester resistor, characterized in that: The insulating coating on the side of a lightning arrester resistor sheet is prepared by the method for preparing the insulating coating on the side of a lightning arrester resistor sheet as described in any one of claims 1 to 9.

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