Embedded insulator coating structure and preparation method and application thereof

Abstract

The invention provides an embedded insulator coating structure and a preparation method and application thereof, and relates to the technical field of insulating materials. The invention provides an embedded insulator coating structure. The embedded insulator coating structure comprises an insulator, a plurality of grooves formed in the surface of the insulator, and room temperature vulcanized silicone rubber anti-pollution flashover coatings filled in the grooves and coated on the surface of the insulator, and the insulator is made of a hydrophilic material. According to the embedded insulator coating structure provided by the invention, the RTV coating (namely the room temperature vulcanized silicone rubber anti-pollution flashover coating) in the groove and the RTV coating on the surface are integrated, and meanwhile, the RTV coating in the groove is embedded into the insulator substrate, so that a mechanical interlocking structure is successfully formed, and the overall adhesive force and durability of the RTV coating are improved. According to the embedded insulator coating structure provided by the invention, the technical problem that a traditional coating type RTV coating structure of an insulator is insufficient in adhesive force and durability is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of insulating materials, and in particular to an embedded insulator coating structure and a preparation method and application thereof. Background Art

[0002] Overhead transmission lines are responsible for the important task of load transmission, and their external insulation level depends entirely on the performance of insulators. The success rate of reclosing in pollution flashover accidents is low, and severe ones will cause large-scale power outages. Therefore, the prevention and control of pollution flashover on insulators has always been a research hotspot in the field of external insulation. The insulating materials of insulators can be divided into two categories: one is hydrophilic materials, such as glass and ceramics, which have the characteristics of aging resistance and excellent mechanical properties, but their electrical properties are slightly worse; the other is hydrophobic materials, such as silicone rubber, which have excellent electrical properties, but their long-term stability is not as good as hydrophilic materials that are mostly inorganic materials. The method of applying room temperature vulcanized silicone rubber (RTV) anti-pollution flashover coating on ceramic and glass insulators cleverly combines hydrophilic materials with hydrophobic materials, ensures electrical performance and long-term mechanical strength, and has been widely used in power systems. However, the life of RTV coating is only 8 to 12 years, which is much lower than the life of inorganic and organic external insulation materials. In recent years, although many new anti-pollution flashover coating structures have been proposed at home and abroad, there has been no significant improvement in durability. For anti-pollution flashover coatings, the research results of State Grid Corporation of China show that the problems of "coating peeling, poor adhesion, and cracking" account for the highest proportion (43%). Insufficient adhesion and poor durability have become urgent problems that need to be solved for anti-pollution flashover coatings. Summary of the invention

[0003] In view of this, the object of the present invention is to provide an embedded insulator coating structure and a preparation method and application thereof. The embedded insulator coating structure provided by the present invention has excellent coating adhesion and durability.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides an embedded insulator coating structure, comprising an insulator, a plurality of grooves arranged on the surface of the insulator, and a room temperature vulcanized silicone rubber anti-pollution flashover coating filled in the grooves and coated on the surface of the insulator; the insulator is made of a hydrophilic material.

[0006] Preferably, the grooves are discrete grooves and / or mesh-like grooves.

[0007] Preferably, the geometric shape of the discrete grooves includes a hole shape and / or a bar shape.

[0008] Preferably, the depth of the groove is 1 to 3 mm.

[0009] Preferably, the width of the groove is 2-5 mm.

[0010] Preferably, the insulator comprises a glass insulator, a ceramic insulator or an epoxy resin insulator.

[0011] Preferably, the room temperature vulcanized silicone rubber anti-pollution flashover coating coated on the surface of the insulator has a thickness of 0.4 to 0.6 mm.

[0012] The present invention provides a method for preparing the embedded insulator coating structure described in the above technical solution, comprising the following steps:

[0013] preparing an insulator having a plurality of grooves on the surface;

[0014] Filling the groove with room temperature vulcanized silicone rubber anti-pollution flashover coating, and after curing, obtaining an insulator with a groove RTV coating;

[0015] A room temperature vulcanized silicone rubber anti-pollution flashover coating is applied on the surface of the insulator with the groove RTV coating, and after curing, the embedded insulator coating structure is obtained.

[0016] Preferably, the method for preparing an insulator having a plurality of grooves on the surface comprises molding or machining.

[0017] The present invention provides the application of the embedded insulator coating structure described in the above technical solution or the embedded insulator coating structure prepared by the preparation method described in the above technical solution in an overhead power transmission line.

[0018] The present invention provides an embedded insulator coating structure, comprising an insulator, a plurality of grooves arranged on the surface of the insulator, and a room temperature vulcanized silicone rubber anti-pollution flashover coating filled in the grooves and coated on the surface of the insulator; the insulator is a hydrophilic material. In the embedded insulator coating structure provided by the present invention, the RTV coating in the grooves (i.e., the room temperature vulcanized silicone rubber anti-pollution flashover coating) and the RTV coating on the surface are an integral whole. At the same time, the RTV coating in the grooves is embedded in the insulator base, successfully forming a mechanical interlocking structure, thereby increasing the overall adhesion and durability of the RTV coating. The embedded insulator coating structure provided by the present invention solves the technical problem of insufficient adhesion and durability of the traditional RTV coating structure of the insulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the non-connected groove structure. Figure 1 The left picture in the middle shows a non-connected groove with a dot (i.e., a round hole) geometry, and the right picture shows a non-connected groove with a round bar geometry;

[0020] Figure 2 Schematic diagram of the connected groove structure ( Figure 2 The upper middle figure) and the connected groove structure size setting in the embodiment ( Figure 2 middle lower figure);

[0021] Figure 3 A schematic diagram of a groove structure in which a non-connected groove and a connected groove are integrated;

[0022] Figure 4 This is a schematic diagram of the structure of a traditional coating RTV coating. Figure 4 The middle left picture shows the insulator substrate, and the right picture shows the coating type RTV coating structure;

[0023] Figure 5 This is a schematic diagram of the structure of an embedded RTV coating according to an embodiment of the present invention. Figure 5 The middle left picture shows an insulator base with a groove structure, and the right picture shows an embedded RTV coating structure;

[0024] Figure 6 This is an advantage of the embedded RTV coating structure of the present invention in the initial stage of operation;

[0025] Figure 7 Advantages of the embedded RTV coating structure of the present invention in the later stage of operation;

[0026] Figure 8 The advantages of the embedded RTV coating structure of the present invention at the end of operation;

[0027] Fig. 9 It is a mixed flat plate sample of RTV coating and glass in the silicone rubber tangential hydrophobic migration test;

[0028] Fig.10 This is the test process of tangential hydrophobic migration of silicone rubber;

[0029] Fig.11 The images of the coating structures of Example 1 and Comparative Example 1 before and after cross-cutting after being boiled in water for 100 hours;

[0030] Fig.12 The images of the coating structures of Example 1 and Comparative Example 1 after being boiled in water for 100 hours and then cross-cutting, then boiled in water for 200 hours, and directly boiled in water for 200 hours and then cross-cutting;

[0031] Fig.13 The images of the coating structure of Comparative Example 1 after being boiled in water for 100 hours and then cross-cutting, boiled in water for 300 hours, boiled in water for 200 hours and then cross-cutting, and boiled in water directly for 300 hours;

[0032] Fig.14 These are images of the coating structure of Example 1 after being boiled in water for 100 hours and then cross-cutting, boiled in water for 300 hours, boiled in water for 200 hours and then cross-cutting, and boiled in water directly for 300 hours;

[0033] Fig.15These are images of the coating structure of Example 1 that was boiled for 100 hours and then boiled for 400 hours, boiled for 200 hours and then boiled for 400 hours, and boiled for 300 hours and then boiled for 400 hours. Fig.15 The left side of each group of images is the image taken directly after removal, and the right side is the image after the failure area of ​​the bonding surface is removed after brushing with a copper wire brush;

[0034] Fig.16 The pH value test result of the alkaline environment aging reagent in the embodiment;

[0035] Fig.17 The images of the coating structure of Comparative Example 1 after cross-cutting after aging in an alkaline environment for 100 hours and then aging in an alkaline environment for 300 hours, and after cross-cutting after direct aging in an alkaline environment for 300 hours;

[0036] Fig.18 The images of the non-connected embedded RTV coating structure sample prepared in Example 1 and the connected embedded RTV coating structure sample prepared in Example 2 before and after being directly aged in an alkaline environment for 300 hours;

[0037] Fig.19 The images are of the non-connected embedded RTV coating structure sample prepared in Example 1 and the connected embedded RTV coating structure sample prepared in Example 2, which were aged in an alkaline environment for 300 hours, followed by cross-cutting and then aged in an alkaline environment for 400 hours. DETAILED DESCRIPTION

[0038] The present invention provides an embedded insulator coating structure, comprising an insulator, a plurality of grooves arranged on the surface of the insulator, and a room temperature vulcanized silicone rubber anti-pollution flashover coating filled in the grooves and coated on the surface of the insulator; the insulator is made of a hydrophilic material.

[0039] The embedded insulator coating structure provided by the present invention comprises an insulator. In the present invention, the insulator is made of a hydrophilic material, and the insulator preferably comprises a glass insulator, a ceramic insulator or an epoxy resin insulator.

[0040] The embedded insulator coating structure provided by the present invention includes a plurality of grooves arranged on the surface of the insulator. In the present invention, the grooves are discrete grooves and / or mesh grooves, the discrete grooves are non-connected grooves, and the mesh grooves are connected grooves. The grooves arranged on the surface of the insulator in the present invention can be non-connected grooves or connected grooves, or a groove structure in which non-connected grooves and connected grooves are integrated. In the present invention, the geometric shape of the discrete grooves preferably includes hole shapes and / or strip shapes, the hole shapes are like round holes, and the strip shapes are like round strips; the corners of the grid formed by the mesh grooves are preferably chamfered. The present invention has no special requirements for the specific arrangement of the grooves, and can be arranged according to the actual working conditions, such as Figures 1 to 3 shown. Figure 1 The left picture in the middle shows a non-connected groove whose geometric shape is a circular hole (or a circular dot), and the right picture shows a non-connected groove whose geometric shape is a circular bar; Figure 2 The grooves are connected to form a network (i.e., the grooves on the insulator base form a "network"); Figure 3 The groove structure is a fusion of non-connected grooves and connected grooves, including mesh grooves and circular hole-shaped grooves discrete in each grid of the mesh groove. In the present invention, the depth of the groove is preferably 1 to 3 mm. The depth of the groove determines the size of the bonding area between the RTV coating and the substrate. If it is too shallow, the RTV coating will be too little embedded in the substrate, and the mechanical chain effect will be too weak, affecting the effect of improving the adhesion. If it is too deep, the mechanical properties of the insulator may be affected. The width of the groove is preferably 2 to 5 mm. When the groove is a hole shape, the width of the groove is the hole diameter. When the groove is a mesh groove, the width of the groove is the width of the mesh line. The present invention has no special requirements for the spacing of the grooves (when the groove is a mesh groove, the spacing of the grooves is the size of the grid size), and it can be set according to the actual working conditions.

[0041] The embedded insulator coating structure provided by the present invention includes a room temperature vulcanized silicone rubber anti-pollution flashover coating filled in the groove and coated on the surface of the insulator. The present invention has no special requirements for the coating forming the room temperature vulcanized silicone rubber anti-pollution flashover coating (i.e., RTV coating), and the room temperature vulcanized silicone rubber anti-pollution flashover coating well known to those skilled in the art can be used. In the present invention, the thickness of the room temperature vulcanized silicone rubber anti-pollution flashover coating coated on the surface of the insulator is preferably 0.4 to 0.6 mm, and can be 0.4, 0.5 or 0.6 mm.

[0042] Figure 4 This is a schematic diagram of the structure of a traditional coating RTV coating, in which the RTV anti-pollution flashover coating is directly coated on the smooth surface of the insulator, that is, the RTV coating only exists on the surface. Figure 5 This is a schematic diagram of the embedded RTV coating structure provided by the present invention (taking the circular hole-shaped non-connected groove as an example). In the embedded RTV coating structure provided by the present invention, the RTV coating in the groove and the RTV coating on the surface are integrated as a whole. At the same time, the RTV coating in the groove is embedded in the insulator base, successfully forming a mechanical interlocking structure, thereby increasing the adhesion and durability of the RTV coating as a whole.

[0043] Below Figure 5 The non-connected embedded coating structure with circular holes as geometric units is taken as an example to illustrate the advantages of the embedded RTV coating structure of the present invention compared with the traditional coated RTV coating structure from the perspective of the operating cycle.

[0044] In the initial operation, the surface coating of the embedded RTV coating structure of the present invention is intact, and the basic characteristics of the embedded RTV coating are consistent with those of the applied RTV coating. It is worth noting that compared with the bonding area per unit area, the bonding area of ​​the RTV coating of the embedded structure is greatly increased because it is embedded in the surface of the insulator base; at the same time, the introduced mechanical interlocking structure can provide mechanical support for the coating to resist the shear stress caused by factors such as wind, sand and stone wear in the operating environment acting on the insulator. Figure 6 Therefore, the introduction of an embedded coating structure can enhance the adhesion between the coating and the substrate, making it more durable.

[0045] When the coating is operated outdoors for a long time, it is under the condition of superposition of electrical stress and environmental stress, and the coating will inevitably age. When the coating ages, the cohesion and interface strength of the material decrease to a certain extent. Figure 4 The surface of the applied RTV coating shown in the figure will be damaged, and the coating is on the verge of failure and needs to be re-coated. However, for the embedded coating of the present invention, due to the material property that the cohesion of the RTV material itself is less than the adhesion, and the aging property that the aging rate of the deep RTV coating is low, the RTV coating embedded in the substrate will not fall off together with the surface coating, such as Figure 7 In addition, the boiling water aging test comparison between the embedded RTV coating structure and the applied RTV coating structure in the embodiment of the present invention also proves the existence of the "coating in the groove does not fall off" phenomenon.

[0046] At the end of operation, the conventional coating RTV coating has failed and the surface has almost completely fallen off. The embedded RTV coating structure with only the RTV coating inside the groove of the present invention can still continue to operate because its pollution flashover voltage is not significantly different from that of the 100% RTV coating. The reason is that the oligomeric cyclic siloxane (mainly D4 and D5) inside the silicone rubber has tangential diffusion behavior, so that the embedded RTV coating structure with only the RTV coating inside the groove still maintains a global hydrophobic state. Due to the existence of the RTV tangential hydrophobic migration phenomenon, the hydrophobicity of its surface is unevenly distributed, such as Figure 8 In addition, the previous tangential hydrophobic migration test of silicone rubber also proved the existence of the phenomenon of "tangential hydrophobic migration of silicone rubber", as shown in Figure 2. Figure 9-10 shown. Fig. 9 For the RTV coating-glass hybrid flat plate sample, Fig. 9 The light red area above is the dirt layer above the RTV coating, and the white area below is the dirt layer above the glass. Fig.10This is the tangential hydrophobic migration test process of silicone rubber. From the RTV-glass interface to the outside, a water drop is dropped every 2 mm (the drop size is fixed at 5 μL). The contact angle test is performed according to GB-T 24622-2022. It can be found that when the water drop falls on the dirt layer above the glass interface, no water film is formed, but a spherical shape is formed. After the water drop is absorbed by low-lint paper, a crater-shaped mark is left on the dirt layer. This phenomenon strongly proves that silicone rubber has significant tangential hydrophobic migration characteristics.

[0047] Therefore, the present invention can enable the embedded RTV coating structure to maintain excellent anti-pollution flashover performance throughout its entire life cycle through reasonable design of the groove topology structure, thereby greatly extending the coating life.

[0048] The present invention provides a method for preparing the embedded insulator coating structure described in the above technical solution, comprising the following steps:

[0049] preparing an insulator having a plurality of grooves on the surface;

[0050] Filling the groove with room temperature vulcanized silicone rubber anti-pollution flashover coating, and after curing, obtaining an insulator with a groove RTV coating;

[0051] A room temperature vulcanized silicone rubber anti-pollution flashover coating is applied on the surface of the insulator with the groove RTV coating, and after curing, the embedded insulator coating structure is obtained.

[0052] In the present invention, the raw materials involved are all commercially available products well known in the art.

[0053] The present invention prepares an insulator having a plurality of grooves on its surface. In the present invention, the method for preparing the insulator having a plurality of grooves on its surface includes molding or machining. The present invention has no special requirements for the specific operation of molding or machining. An insulator having a plurality of grooves that meets the size and arrangement can be obtained by using an operation method well known to those skilled in the art.

[0054] After obtaining an insulator with multiple grooves, the present invention fills the grooves with room temperature vulcanized silicone rubber anti-pollution flashover coating, and after curing, an insulator with groove RTV coating is obtained. The present invention has no special requirements for the filling method, and a filling method well known to those skilled in the art can be used, such as a scraping process. The present invention has no special requirements for the curing conditions, and the curing conditions of room temperature vulcanized silicone rubber anti-pollution flashover coating well known to those skilled in the art can be used.

[0055] After obtaining the insulator with groove RTV coating, the present invention applies room temperature vulcanized silicone rubber anti-pollution flashover coating on the surface of the insulator with groove RTV coating, and after curing, the embedded insulator coating structure is obtained. The present invention has no special requirements for the application method, and the application method familiar to those skilled in the art can be used, such as a dipping process. The present invention has no special requirements for the curing conditions, and the curing conditions of room temperature vulcanized silicone rubber anti-pollution flashover coating familiar to those skilled in the art can be used.

[0056] The present invention provides an application of the embedded insulator coating structure described in the above technical solution or the embedded insulator coating structure prepared by the preparation method described in the above technical solution in an overhead transmission line. The embedded insulator coating structure provided by the present invention has excellent coating adhesion and durability. The present invention has no special requirements for the application method, and the application method familiar to those skilled in the art can be used.

[0057] In order to further illustrate the present invention, the embedded insulator coating structure provided by the present invention and its preparation method and application are described in detail below in combination with examples, but they should not be understood as limiting the protection scope of the present invention.

[0058] Example 1

[0059] An embedded insulator coating structure (i.e., embedded RTV coating structure) is prepared in the following steps:

[0060] On a 140×80×5mm FR4 epoxy resin substrate, non-connected circular hole-shaped grooves with a diameter of 2mm and a depth of 1mm were prepared using a mechanical processing process. The spacing between the circular hole-shaped grooves was 2mm (the spacing between the centers of two adjacent circular hole-shaped grooves was 4mm), and the circular hole-shaped grooves in adjacent rows were arranged in a staggered manner, such as Figure 1 As shown in the middle left picture;

[0061] The circular hole-shaped groove is filled with room temperature vulcanized silicone rubber (RTV) anti-pollution flashover coating (purchased from Hebei Silicon Valley Chemical Co., Ltd., PRTV (RTV-Ⅱ)) by scraping process, and cured for 1 hour at 25° C. and 60% relative humidity to obtain an insulator with a groove RTV coating;

[0062] Next, a room temperature vulcanized silicone rubber (RTV) anti-pollution flashover coating with a thickness of 0.5 mm was prepared on the surface of the insulator sample with a groove RTV coating using a dip coating process. The curing conditions of the RTV coating were 25° C. and 60% relative humidity for 1 hour.

[0063] Comparative Example 1

[0064] A conventional flat RTV coating sample (i.e., coated RTV coating) is directly prepared using a dip coating process by using a room temperature vulcanized silicone rubber anti-fouling flashover coating (the same as in Example 1) on the surface of a FR4 epoxy resin substrate (the same as in Example 1) to form an RTV coating with a thickness of 0.5 mm.

[0065] Example 2

[0066] An embedded insulator coating structure (i.e., embedded RTV coating structure) is prepared in the following steps:

[0067] On a 140×80×5mm FR4 epoxy resin substrate, a connected mesh groove was prepared using a machining process, such as Figure 2 As shown, the line width of the mesh groove is 3 mm, the depth is 1 mm, the side length of the hydrophilic square grid is 15 mm, and the adjacent sides form a chamfer with a radius of 2 mm;

[0068] The mesh grooves were filled with room temperature vulcanized silicone rubber (RTV) anti-pollution flashover coating (purchased from Hebei Silicon Valley Chemical Co., Ltd., PRTV (RTV-II)) by scraping process, and cured for 1 hour at 25° C. and 60% relative humidity to obtain an insulator with groove RTV coating;

[0069] Next, a room temperature vulcanized silicone rubber (RTV) anti-pollution flashover coating with a thickness of 0.5 mm was prepared on the surface of the insulator sample with a groove RTV coating using a dip coating process. The curing conditions of the RTV coating were 25° C. and 60% relative humidity for 1 hour.

[0070] The durability and adhesion of the embedded RTV coating structure prepared in the embodiment and the conventional flat RTV coating structure in the comparative example were compared by the boiling method, as follows:

[0071] Boiling test method:

[0072] The temperature of the constant temperature water bath was set to 99°C, and the embedded RTV coating sample of Example 1 and the traditional flat RTV coating sample of Comparative Example 1 were subjected to water boiling aging; according to the cross-hatch method in ISO2409 and GB-T9286, the adhesion of the samples after different water boiling times was tested (after cross-hatch with a hundred-grid knife, the weakly bonded coating was brushed off with a copper wire brush).

[0073] Test method and test results:

[0074] (1) Test method 1: Boil the sample in water for 100 hours and then cross-cut for adhesion test; the test results are as follows: Fig.11As shown. For the samples of the applied RTV coating of comparative example 1 and the embedded RTV coating of example 1, no blisters appeared on the surface, and the adhesion was qualified according to IEC TR62039-2021. The traditional RTV coating would fall off by more than 20%, and the adhesion was level 3, while the embedded coating structure of example 1 had about 10% of the squares fall off, and the adhesion was level 2.

[0075] (2) Test method 2: Boil the sample in water for 100 hours and then cut the grid. Then boil the sample in water for 200 hours and then cut the grid. The test results are as follows: Fig.12 As shown. The adhesion of the two coating structures degraded to below level 4, but the RTV coating embedded in the substrate of Example 1 did not fall off. For the 200h cross-cut sample: the adhesion of the two structures was level 3-4 (comparative example 1 traditional RTV coating) and level 2-3 (embedded RTV coating of Example 1), and the falling area of ​​the coating of Example 1 was much smaller than that of the coated RTV coating sample of Comparative Example 1.

[0076] (3) Test method 3: boil the sample for 100 hours and then cross-cut it, then boil it for 300 hours, boil the sample for 200 hours and then cross-cut it, then boil it for 300 hours, and boil the sample directly for 300 hours and then cross-cut it; the test results are as follows: Fig.13 and Fig.14 shown. Fig.13 This is the test result of the coating structure of Example 1. Fig.13 The left picture of the 300h cross-cut group is the image after 300h water boiling and cross-cutting, and the right picture is the image after 300h water boiling and cross-cutting with a copper wire brush to remove the weakly bonded coating. Fig.14 is the test result of the coating structure of Example 1, Fig.14 The left picture in the experimental group of 200h cross-cut boiling to 300h is the image of 200h cross-cut boiling to 300h, and the right picture is the image after the weak bonding coating was brushed off with a copper wire brush. Fig.14 In the 300h cross-cutting group, the left picture shows the image before the cross-cutting after 300h of boiling, and the right picture shows the image after the cross-cutting after 300h of boiling. For the traditional flat RTV coating structure, regardless of whether the coating was damaged by cross-cutting before 300h, the traditional flat RTV coating structure has completely failed after 300h of boiling, with large-area blisters, and the coating can be easily torn off from the substrate. For the embedded RTV coating structure sample of Example 1, regardless of whether the coating was damaged by cross-cutting before 300h, the RTV coating embedded in the substrate will not fall off. For the sample that was boiled in water for 300h and then cross-cut, the adhesion of the embedded coating of Example 1 degraded to level 4.

[0077] (4) Test method 4: boil the sample for 100 hours, cross-cut and then boil for 400 hours; boil the sample for 200 hours, cross-cut and then boil for 400 hours; and boil the sample for 300 hours, cross-cut and then boil for 400 hours. After boiling for 400 hours, the conventional flat RTV coating structure samples have all failed. The test results of the embedded RTV coating structure samples of Example 1 are as follows: Fig.15 As shown ( Fig.15 The left side of each group of pictures is the image taken directly after removal, and the right side is the image after removing the failed area of ​​the bonding surface after brushing with a copper wire brush). The RTV coating embedded in the substrate will not fall off.

[0078] From the above test results, it can be seen that the embedded RTV coating samples have better durability and better adhesion. The introduction of embedded RTV coating can delay the degradation rate of adhesion by more than 100 hours. The RTV coating embedded in the substrate will not fall off. The reasons are:

[0079] The moisture intrusion rate of deep bonding surface is slower, and the aging rate is slower;

[0080] Boiling water can cause serious damage to the cohesive strength of RTV coatings. After boiling for 200 hours, the RTV substrate is almost completely destroyed, making its cohesive strength less than its adhesive strength.

[0081] The RTV embedded in the substrate provides mechanical support to the surface RTV coating, making it less likely to fall off.

[0082] The alkaline environment aging method was used to compare the durability and adhesion of the embedded RTV structure and the traditional flat plate structure, as follows:

[0083] Alkaline environment aging reagent: prepare 1 mol / L solution and check the pH to be 14. Fig.16 shown.

[0084] Test method: At room temperature (25°C), immerse the sample to be tested in the configured aging reagent, and test the adhesion of the sample after aging in alkaline environment for different time periods according to the cross-cut method in ISO2409 and GB-T9286.

[0085] Test results:

[0086] (1) The samples were aged in an alkaline environment for 100 hours and then cross-sectionalized; the samples were aged in an alkaline environment for 300 hours and then cross-sectionalized; and the samples were directly aged in an alkaline environment for 300 hours. Fig.17 The test results of comparative example 1 are as follows: the conventional flat RTV coating is aged in an alkaline environment for 100 hours and then aged in an alkaline environment for 300 hours, and then aged in an alkaline environment for 300 hours. Fig.17The left images of the two test groups are the images before brushing with a copper wire brush, and the right images are the images after brushing off the weakly bonded coating with a copper wire brush. 300h alkaline environment aging causes serious damage to the adhesion of the RTV coating. For the traditional flat RTV coating structure, the adhesion is obviously degraded to level 5. The RTV coating can be easily peeled off from the surface.

[0087] (2) The non-connected embedded RTV coating structure samples prepared in Example 1 and the connected embedded RTV coating structure samples prepared in Example 2 were directly aged in an alkaline environment for 300 hours. The test results are as follows: Fig.18 As shown in Figure 2, after 300h of alkaline environment aging, the adhesion of the non-connected and connected embedded structure samples degraded to level 2.

[0088] (3) The samples were tested after being aged in an alkaline environment for 300 hours and then aged in an alkaline environment for 400 hours. The test results showed that after 400 hours of alkaline environment aging, all the conventional flat RTV coating samples had failed. For the non-connected embedded RTV coating structure samples of Example 1, the RTV on the surface and embedded in the substrate in the area away from the exposed bonding surface would not fall off. For the connected embedded RTV coating structure samples of Example 2, the RTV coating in the middle of the square protected by the strip grooves was not easy to fall off. The corresponding test results of the coatings of Example 1 and Example 2 are shown in FIG. Fig.19 .

[0089] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An embedded insulator coating structure, characterized in that: The invention comprises an insulator, a plurality of grooves arranged on the surface of the insulator, and a room temperature vulcanized silicone rubber anti-pollution flashover coating filled in the grooves and coated on the surface of the insulator; the insulator is made of hydrophilic material.

2. The embedded insulator coating structure according to claim 1, characterized in that: The grooves are discrete grooves and / or mesh-like grooves.

3. The embedded insulator coating structure according to claim 2, characterized in that: The geometric shapes of the discrete grooves include hole shapes and / or bar shapes.

4. The embedded insulator coating structure according to any one of claims 1 to 3, characterized in that: The depth of the groove is 1 to 3 mm.

5. The embedded insulator coating structure according to claim 4, characterized in that: The width of the groove is 2-5 mm.

6. The embedded insulator coating structure according to claim 1, characterized in that: The insulator includes a glass insulator, a ceramic insulator or an epoxy resin insulator.

7. The embedded insulator coating structure according to claim 1, characterized in that: The thickness of the room temperature vulcanized silicone rubber anti-pollution flashover coating coated on the surface of the insulator is 0.4-0.6 mm.

8. The method for preparing the embedded insulator coating structure according to any one of claims 1 to 7, characterized in that: The following steps are involved: preparing an insulator having a plurality of grooves on the surface; Filling the groove with room temperature vulcanized silicone rubber anti-pollution flashover coating, and after curing, obtaining an insulator with a groove RTV coating; A room temperature vulcanized silicone rubber anti-pollution flashover coating is applied on the surface of the insulator with the groove RTV coating, and after curing, the embedded insulator coating structure is obtained.

9. The preparation method according to claim 8, characterized in that: The method for preparing an insulator with a plurality of grooves on the surface includes molding or machining.

10. Use of the embedded insulator coating structure according to any one of claims 1 to 7 or the embedded insulator coating structure prepared by the preparation method according to claim 8 or 9 in overhead power transmission lines.

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