Insulating material, prefabricated intermediate joint assembly and preparation method

Abstract

The invention discloses an insulating material, a prefabricated intermediate joint assembly and a preparation method. The insulating material comprises the following components in parts by weight: 30-50 parts of ethylene propylene diene monomer, 10-20 parts of a peroxide vulcanizing agent, 10-20 parts of a reinforcing agent, 10-20 parts of a filler, 10-20 parts of a plasticizer and 10-20 parts of a stabilizer. 2-3.5 parts of a peroxide vulcanizing agent; 0.05-1 part of a reinforcing agent; 9-11 parts of a plasticizer; 1-2.5 parts of a stabilizer; and 25-30 parts of a filler. The prefabricated intermediate joint assembly comprises an insulating part, a stress part, an electrode part and an outer conducting layer, wherein the insulating part is formed by injection vulcanization of an insulating material containing ethylene propylene diene monomer. The insulating material provided by the invention has excellent mechanical properties and aging resistance; and through autonomous production, the manufacturing cost of the material is reduced, and good economic benefits are produced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of materials, in particular to an insulating material, a prefabricated intermediate joint assembly and a preparation method. BACKGROUND

[0002] At present, the prefabricated cable intermediate joints on the market mainly have two materials of silicone rubber and ethylene-propylene-diene rubber. Both of the rubbers can meet the use requirements. The silicone rubber has good heat resistance, easy processability and shrinkability, but poor tear resistance and over-voltage resistance. The ethylene-propylene-diene rubber has good tear resistance and over-voltage resistance. Since the ethylene-propylene-diene rubber has high tear strength and excellent over-voltage resistance, in long-distance power transmission lines with voltage grades of 220 kV and above, the recognition of the ethylene-propylene-diene rubber material cable intermediate joint products by mainstream power grid companies is gradually increasing. However, the ethylene-propylene-diene rubber intermediate joint in the traditional technology still has the following problems: (1) in the field of high voltage and super high voltage, the traditional ethylene-propylene-diene rubber material source needs to rely on import, and is affected by many factors such as international situation and upstream materials, and has great risks in supply and cost control; (2) the traditional ethylene-propylene-diene rubber intermediate joint product has large volume, high rubber hardness, poor shrinkability, and low production qualified rate. SUMMARY

[0003] Therefore, it is necessary to provide an insulating material with excellent mechanical properties and aging resistance, a prefabricated intermediate joint assembly and a preparation method.

[0004] An embodiment of the present application provides an insulating material.

[0005] An insulating material includes ethylene-propylene-diene rubber, peroxide vulcanizing agent, reinforcing agent, filler, plasticizer and stabilizer, and each component satisfies the following weight ratio:

[0006] The ethylene-propylene-diene rubber is 30-50;

[0007] The peroxide vulcanizing agent is 2-3.5;

[0008] The reinforcing agent is 0.05-1;

[0009] The plasticizer is 9-11;

[0010] The stabilizer is 1-2.5;

[0011] and the filler is 25-30.

[0012] In some embodiments, the peroxide vulcanizing agent in the insulating material includes peroxide ester.

[0013] In some embodiments, the peroxide ester includes one or more of dicumyl peroxide, dibenzoyl peroxide, and benzoyl peroxide.

[0014] In some embodiments, the reinforcing agent in the insulating material includes one or more of carbon black, silane coupling agent, and calcium carbonate.

[0015] In some embodiments, the plasticizer in the insulating material includes one or more of paraffin oil, naphthenic oil, and stearic acid.

[0016] In some embodiments, the stabilizer in the insulating material includes one or more of antioxidant and anti-aging agent.

[0017] In some embodiments, the filler in the insulating material includes one or more of kaolin, calcium carbonate, and talcum powder.

[0018] An embodiment of the present application further provides a prefabricated intermediate joint assembly.

[0019] A prefabricated intermediate joint assembly includes an insulating component, a stress component, an electrode component, and an outer conductor layer, the insulating component is provided with a joint channel along an axial direction thereof, the stress component is connected to each end of the joint channel, each stress component protrudes from a corresponding end surface of the insulating component, the electrode component is connected to an inner wall of the joint channel, and the outer conductor layer is connected to an outer wall of the insulating component.

[0020] In some embodiments, the stress component has electrically conductive or semi-conductive capability.

[0021] In some embodiments, the stress component has a ring structure, the insulating component is provided with a ring-shaped clamping groove around the joint channel at each end surface along the joint channel, and each stress component is embedded in the corresponding clamping groove.

[0022] In some embodiments, the stress component has a whole ring structure.

[0023] In some embodiments, an inner wall of the stress component is flush with an inner wall of the joint channel.

[0024] In some embodiments, an outer diameter D1 of the stress component is 200mm-250mm.

[0025] In some embodiments, the inner wall of the annular clamping groove closest to the joint channel is tapered from the groove opening to the groove bottom surface.

[0026] In some embodiments, the inner wall of the annular clamping groove closest to the joint channel is curved.

[0027] In some embodiments, the inner wall of the annular clamping groove closest to the joint channel is spherically tapered.

[0028] In some embodiments, the spherical radius R of the inner wall of the annular clamping groove closest to the joint channel is 90mm-120mm.

[0029] In some embodiments, the inner wall of the annular clamping groove closest to the joint channel is tapered from the groove opening to the groove bottom surface to the inner wall farthest from the joint channel.

[0030] In some embodiments, the distance L1 of each second end portion protruding from the end surface of the insulating member is 20mm-80mm.

[0031] In some embodiments, the second end portion is in the form of a boss structure.

[0032] In some embodiments, the electrode member is in the form of an annular structure.

[0033] In some embodiments, the electrode member is embedded in the inner wall of the joint channel, and the inner wall of the electrode member is flush with the inner wall of the joint channel.

[0034] In some embodiments, the electrode member is in the form of a circular ring structure.

[0035] In some embodiments, the inner diameter D2 of the electrode member is 90mm-120mm.

[0036] In some embodiments, the thickness W1 of the electrode member is 5mm-40mm.

[0037] In some embodiments, the outer conductor layer is in the form of an annular structure.

[0038] In some embodiments, the outer conductor layer is embedded in the outer wall of the insulating member, and the outer wall of the outer conductor layer is flush with the outer wall of the insulating member.

[0039] In some embodiments, the outer conductor layer has a circular ring structure.

[0040] In some embodiments, the thickness W2 of the outer conductor layer is 5mm-20mm.

[0041] In some embodiments, the length L2 of the prefabricated intermediate joint assembly along the axial direction of the insulation component is 800mm-1000mm.

[0042] In some embodiments, the insulation component has a cylindrical structure as a whole, and the outer diameter D3 of the insulation component is 200mm-300mm.

[0043] In some embodiments, the minimum distance L3 between the stress component and the electrode component along the axial direction of the insulation component is 100mm-150mm.

[0044] An embodiment of the present application further provides a preparation method of a prefabricated intermediate joint assembly.

[0045] A preparation method of a prefabricated intermediate joint assembly, comprising the following steps:

[0046] The stress component, the electrode component and the outer conductor layer are respectively sleeved on the preset positions on the support mold, wherein the two stress components are arranged at intervals, the electrode component is arranged between the two stress components, the outer conductor layer at least partially covers the electrode component, and gaps exist between the outer conductor layer and the electrode component and between the outer conductor layer and the stress component;

[0047] The insulation material containing EPDM is injected into the gaps between the outer conductor layer and the electrode component and between the outer conductor layer and the stress component to vulcanize and form the insulation component, and the insulation component connects the stress component, the electrode component and the outer conductor layer;

[0048] And the support mold is removed to form a joint channel penetrating in the axial direction of the insulation component.

[0049] In some embodiments, before the injection vulcanization forming, the insulation material is subjected to a mixing treatment, and the mixing treatment comprises banburying, open milling, filtering, thin passing and calendering.

[0050] In some embodiments, the single banburying time is controlled to be not more than 10min.

[0051] In some embodiments, the temperature of the insulation material after the mixing treatment is controlled to be not higher than 90℃.

[0052] In some embodiments, after the mixing process of the insulating material, the tensile strength of the insulating material is greater than 5 MPa, the elongation is greater than 320%, the hardness is 55-65, and the compression permanent set is 8%-15%.

[0053] The insulating material of the present application can replace the silicone rubber in the traditional technology for preparing the intermediate joint, and solve the problems of dependence on imported raw materials and low production qualification rate of rubber products.

[0054] The prefabricated intermediate joint assembly described above includes a stress component, an electrode component, an outer conductor layer, and an insulating component. The stress component, the electrode component, and the outer conductor layer are connected by the insulating component formed by injection vulcanization of the insulating material containing ethylene-propylene-diene rubber material. The prefabricated intermediate joint assembly prepared has a small volume, can solve the problems of poor tear resistance and over-voltage resistance of silicone rubber intermediate joints, and is beneficial to the reliable operation quality of accessory products in high-voltage and long-distance power transmission lines. The prefabricated intermediate joint assembly of the present application can replace the use of silicone rubber intermediate joints, and solve the problems of dependence on imported raw materials and low production qualification rate of existing products.

[0055] In summary, compared with the traditional technology, the present application has the following beneficial effects:

[0056] (1) Compared with the insulating material in the traditional technology, the present application successfully replaces the ethylene-propylene-diene rubber in the traditional technology, and solves the defects of poor tear resistance and over-voltage resistance of silicone rubber.

[0057] (2) Compared with the imported material prepared ethylene-propylene-diene rubber, the present application solves the problem of long-term dependence on imports in the super-high voltage field, and the risk of supply and cost control caused by the influence of international situation and upstream materials, and realizes the self-control of product raw materials.

[0058] (3) By analyzing and optimizing the product structure, the present application can cover the application voltage level of the whole prefabricated ethylene-propylene-diene rubber intermediate joint above 66 kV-500 kV, and realizes the breakthrough of the application of domestic whole prefabricated ethylene-propylene-diene rubber intermediate joint in the super-high voltage field. BRIEF DESCRIPTION OF DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0060] For a more complete understanding of the present application, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings. In the following description, like reference numerals are used to denote like elements, unless the context dictates otherwise.

[0061] Figure 1 A cross-sectional view of a prefabricated intermediate joint assembly according to an embodiment of the present application;

[0062] Figure 2 A schematic view of a prefabricated intermediate joint assembly according to an embodiment of the present application;

[0063] Figure 3 A schematic view of a prefabricated intermediate joint assembly according to an embodiment of the present application;

[0064] Figure 4 A schematic view of a prefabricated intermediate joint assembly according to an embodiment of the present application;

[0065] BRIEF DESCRIPTION OF DRAWINGS

[0066] 10. A prefabricated intermediate joint assembly; 100. An insulating part; 200. A stress part; 210. A first end part; 220. A second end part; 221. A boss structure; 300. An electrode part; 400. An outer conductor layer; 20. A cable. DETAILED DESCRIPTION

[0067] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, a lot of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many different ways other than those described herein, and one of ordinary skill in the art can make similar improvements without departing from the spirit of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0068] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0069] In the present application, unless specifically stated and limited otherwise, the terms "mounting", "connected", "connection", "fixed", and the like, should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0070] In the present application, unless specifically stated and limited otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0071] In the description of the present application, if the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If it is described that the first, the second is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the sequence of indicated technical features.

[0072] In this paper, "optionally", "optional", "optional" means optional, that is, optional from "have" or "no" two parallel schemes. If there are multiple "optional" in a technical solution, unless otherwise specified, and there is no contradiction or mutual restriction, each "optional" is independent of each other. In the present application, "optionally contains", "optionally contains" and the like, means "contains or does not contain".

[0073] In the present application, if there is no contrary statement, the sum of the parts of each component in the composition can be 100 parts by weight.

[0074] In this paper, unless otherwise stated, each reaction step can be carried out in the order described herein, or can not be carried out in the order described herein. For example, each reaction step can contain other steps, and the order of the reaction steps can also be appropriately changed. This can be determined by the skilled person according to conventional knowledge and experience. Preferably, the reaction method herein is carried out in sequence.

[0075] In the present application, when a numerical interval (i.e., a numerical range) is involved, the distribution of the optional numbers in the numerical interval is considered to be continuous and includes both numerical endpoints (i.e., the minimum value and the maximum value) of the numerical interval and each number between the two numerical endpoints, unless otherwise specified. When a numerical interval refers only to integers in the numerical interval, including both endpoint integers and each integer between the two endpoints, it is equivalent to directly listing each integer, unless otherwise specified. When multiple numerical ranges are provided to describe a feature or a characteristic, the numerical ranges can be combined. In other words, unless otherwise indicated, the numerical ranges disclosed in the present application should be understood to include any and all sub-ranges therein. The "numbers" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. The "numerical interval" is intended to broadly include quantitative intervals such as percentage intervals, ratio intervals, value intervals, etc.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0077] An embodiment of the present application provides an insulating material, a prefabricated intermediate joint assembly 10 and a preparation method to solve at least one of the following problems of the traditional EPDM intermediate joint: (1) In the field of high pressure and ultra-high pressure, the source of EPDM material needs to rely on imports, which is affected by many factors such as international situation and upstream materials, and has a great risk of supply and cost control; (2) The EPDM intermediate joint product has large volume, high rubber hardness, poor shrinkability, and low production pass rate. The prefabricated intermediate joint assembly 10 will be described below in conjunction with the accompanying drawings.

[0078] An embodiment of the present application provides an insulating material.

[0079] The insulating material includes EPDM, peroxide curing agent, reinforcing agent, filler, plasticizer and stabilizer, and the proportions of the components satisfy the following weight proportions:

[0080] EPDM 30-50;

[0081] Peroxide curing agent 2-3.5;

[0082] Reinforcing agent 0.05-1;

[0083] Plasticizer 9-11;

[0084] Stabilizer 1-2.5;

[0085] and a filler 25-30.

[0086] The above-mentioned insulating material can be used in prefabricated intermediate joint assemblies. The insulating material of the present application can replace the silicone rubber in the prior art for the preparation of intermediate joints, thereby solving the problems of raw material dependence on imports and low production qualification rate of rubber products.

[0087] In some embodiments, the insulating material comprises the following components by weight:

[0088] EPDM rubber 35-45;

[0089] Peroxide vulcanizing agent 2.5-3;

[0090] Reinforcing agent 0.1-0.8;

[0091] Plasticizer 9-10;

[0092] Stabilizer 1.5-2;

[0093] and a filler 28-30.

[0094] In some embodiments, the peroxide vulcanizing agent in the insulating material comprises a peroxy ester. Peroxy ester is a class of ester compounds containing peroxide groups (-O-O-), which generally have high chemical activity and are widely used in polymer chemistry, oxidation reactions, and as initiators, etc.

[0095] In some embodiments, the peroxy ester comprises one or more of dicumyl peroxide (DCP), dibenzoyl peroxide (BPO), and benzoyl peroxide.

[0096] In some embodiments, the reinforcing agent in the insulating material comprises one or more of carbon black, silane coupling agent, and calcium carbonate. Silane coupling agent is a class of organosilicon compounds with special chemical structure, which contains both functional groups (such as siloxane groups) that can react with inorganic materials and organic functional groups that can react or be compatible with organic polymers. They are widely used in composite materials, coatings, adhesives, sealants, etc. to improve the bonding performance and interface properties between different materials.

[0097] In some embodiments, the silane coupling agent comprises one or more of amino silane, epoxy silane, vinyl silane, methacryloyloxy silane, and mercapto silane.

[0098] In some embodiments, the plasticizer in the insulating material comprises one or more of paraffin oil, naphthenic oil, and stearic acid.

[0099] In some embodiments, the stabilizer in the insulating material includes one or more of an antioxidant, an anti-aging agent.

[0100] An antioxidant is a chemical substance that can inhibit or slow down the oxidation process of other substances. They prevent or reduce the occurrence of oxidation reactions by neutralizing free radicals (such as oxygen radicals, peroxides, etc.), thereby protecting materials from damage. For example, antioxidants include one or more of vitamin C, vitamin E, beta-carotene, anthocyanins, polyphenolic compounds (such as tea polyphenols, grape seed extract), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate (PG), and tertiary butyl hydroquinone (TBHQ).

[0101] Anti-aging agents refer to chemical additives used to delay the aging process of materials, especially in high molecular materials such as rubber, plastic, etc., which can prevent or slow down the aging phenomenon caused by oxidation, heat, light, etc., thereby extending the service life of the material and maintaining its performance stability. For example, anti-aging agents include one or both of phenyl-beta-naphthylamine (PBNA) and 2,6-di-tert-butyl-p-cresol (BHT).

[0102] In some embodiments, the filler in the insulating material includes one or more of kaolin, calcium carbonate, and talc.

[0103] An embodiment of the present application provides a prefabricated intermediate joint assembly 10, as shown in the example Figure 1 , Figure 1 The prefabricated intermediate joint assembly 10 provided by an embodiment of the present application is a cross-sectional structure diagram. The prefabricated intermediate joint assembly 10 product of the present application has small volume, can reduce hardness, improve shrinkage, and can improve production yield.

[0104] In order to more clearly illustrate the structure of the prefabricated intermediate joint assembly 10, the prefabricated intermediate joint assembly 10 will be introduced in combination with the drawings.

[0105] As shown in the example Figure 1 , a prefabricated intermediate joint assembly 10 includes an insulating component 100, a stress component 200, an electrode component 300, and an outer conductor layer 400. The insulating component 100 has a joint channel running through it in the axial direction. The joint channel is used for installing the cable 20, as shown in Figure 2 , Figure 2The installation diagram of the prefabricated intermediate joint assembly 10 of an embodiment of the present application is shown. The stress component 200 is connected to the two ends of the joint channel respectively through the insulation component 100. Each stress component 200 protrudes from the corresponding end face of the insulation component 100. The inner wall of the joint channel is connected with the electrode component 300. The outer conductor layer 400 is connected to the outer wall of the insulation component 100. The insulation component 100 is formed by injection vulcanization of the insulation material containing ethylene-propylene-diene rubber.

[0106] The prefabricated intermediate joint assembly 10 described above includes the stress component 200, the electrode component 300, the outer conductor layer 400, and the insulation component 100, and the stress component 200, the electrode component 300, and the outer conductor layer 400 are connected through the insulation component 100 formed by injection vulcanization of the insulation material containing ethylene-propylene-diene rubber. The prefabricated intermediate joint assembly 10 prepared in this way can solve the problem of poor tear resistance and over-voltage resistance of the intermediate joint made of silicone rubber, and is beneficial to the reliable operation quality of accessory products in high-voltage and long-distance power transmission lines. The prefabricated intermediate joint assembly 10 of the present application can replace the use of silicone rubber intermediate joints, and solve the problems of dependence on imported raw materials and low production qualification rate of existing products.

[0107] In some embodiments, the stress component 200 has electrically conductive or semi-conductive capability.

[0108] In some embodiments, the electrode component 300 includes a high-voltage electrode. The high-voltage electrode refers to a conductor or conductive component that works in a high-voltage environment, and is usually used to generate, conduct, measure, or control high-voltage electric field or current. In the present application, the shape, material, and insulation method of the high-voltage electrode will vary according to different application scenarios. In high-voltage power transmission lines, the high-voltage electrode usually refers to the conductive part of devices such as insulators, arresters, circuit breakers, etc.

[0109] In some embodiments, the material of the electrode component 300 includes one or more of copper, aluminum, tungsten, and stainless steel, and the material of the electrode component 300 satisfies the metal material with good electrical conductivity and high temperature resistance.

[0110] In some embodiments, the electrode component 300 is subjected to surface treatment to make the surface smooth to reduce corona discharge and avoid the effect of sharp-end discharge.

[0111] In some embodiments, please refer to Figure 1 As shown in the figure, the stress component 200 has a ring structure. The insulation component 100 is provided with a ring-shaped clamping groove around the joint channel at the two end faces of the joint channel, and each stress component 200 is embedded in the corresponding clamping groove.

[0112] In some embodiments, the stress component 200 has a whole circular ring structure.

[0113] In some embodiments, the inner wall of the stress member 200 is flush with the inner wall of the joint channel.

[0114] In some embodiments, the outer diameter D1 of the stress member 200 is 200mm-250mm. The outer diameter D1 of the stress member 200 includes, but is not limited to, 200mm, 210mm, 230mm, 250mm, or a range between any two of the aforementioned values.

[0115] In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface. Figure 1 In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface.

[0116] In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface. Figure 1 In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface.

[0117] In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface.

[0118] In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface.

[0119] In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface.

[0120] In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface.

[0121] In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface. Figure 1 In some embodiments, referring to FIG. 2A, the inner wall of the annular clamping groove closest to the inner wall of the joint channel is tapered from the groove opening to the groove bottom surface.

[0122] In some embodiments, the electrode component 300 has a ring-shaped structure.

[0123] In some of these implementations, please refer to Figure 1 As shown, the electrode component 300 is embedded in the inner wall of the connector channel, and the inner wall of the electrode component 300 is flush with the inner wall of the connector channel.

[0124] In some embodiments, the electrode component 300 has an annular structure. Alternatively, see... Figure 1 The electrode component 300 is coaxial with the insulating component 100. When the electrode component 300 has a cylindrical annular symmetrical structure, the electric field concentration can be reduced.

[0125] In some embodiments, the inner diameter D2 of the electrode component 300 is 90 mm to 120 mm. The value of the inner diameter D2 of the electrode component 300 includes, but is not limited to, 90 mm, 100 mm, 110 mm, 120 mm or any range between the two mentioned above.

[0126] In some embodiments, the thickness W1 of the electrode component 300 is 5 mm to 40 mm. The value of the thickness W1 of the electrode component 300 includes, but is not limited to: 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm or any range between the foregoing.

[0127] In some of these implementations, please refer to Figure 1 As shown, the outer conductive layer 400 has a ring structure.

[0128] In some embodiments, the outer conductive layer 400 is embedded in the outer wall of the insulating component 100, and the outer wall of the outer conductive layer 400 is flush with the outer wall of the insulating component 100.

[0129] In some embodiments, the outer conductive layer 400 has an annular structure. Optionally, the outer conductive layer 400 is coaxial with the insulating component 100.

[0130] In some embodiments, the thickness W2 of the outer conductive layer 400 is 5 mm to 20 mm. The value of the thickness W2 of the outer conductive layer 400 includes, but is not limited to, 5 mm, 10 mm, 15 mm, 20 mm or any range between the two mentioned above.

[0131] In some of these implementations, please refer to Figure 1 As shown, the length L2 of the prefabricated intermediate joint assembly 10 along the axial direction of the insulating component 100 is 800mm to 1000mm. The value of the length L2 of the prefabricated intermediate joint assembly 10 along the axial direction of the insulating component 100 includes, but is not limited to: 800mm, 850mm, 900mm, 1000mm or any range between the two mentioned above.

[0132] In some embodiments, the insulation component 100 has a cylindrical structure as a whole, and the outer diameter D3 of the insulation component 100 is 200mm-300mm. The outer diameter D3 of the insulation component 100 includes but is not limited to 200mm, 250mm, 300mm, or a range between any two of the foregoing.

[0133] In some embodiments, as shown in Figure 1 the minimum distance L3 between the stress component 200 and the electrode component 300 along the axial direction of the insulation component 100 is 100mm-150mm. The minimum distance L3 between the stress component 200 and the electrode component 300 along the axial direction of the insulation component 100 includes but is not limited to 100mm, 120mm, 130mm, 150mm, or a range between any two of the foregoing.

[0134] In some embodiments, as shown in Figure 1 When the insulation component 100 has a cylindrical structure as a whole, the stress component 200 has a circular ring structure as a whole, the electrode component 300 has a circular ring structure, and the outer conductor layer 400 has a circular ring structure, the insulation component 100, the stress component 200, the electrode component 300, and the outer conductor layer 400 are coaxial.

[0135] An embodiment of the present application further provides a preparation method of the prefabricated intermediate joint assembly 10.

[0136] A preparation method of the prefabricated intermediate joint assembly 10, as shown in Figure 3 the preparation method of the prefabricated intermediate joint assembly 10 includes the following steps: Figure 3 The preparation process flow diagram of the prefabricated intermediate joint assembly according to an embodiment of the present application includes the following steps:

[0137] S10, the stress component 200, the electrode component 300, and the outer conductor layer 400 are respectively sleeved on the preset positions of the support mold, wherein the two stress components 200 are arranged at intervals, the electrode component 300 is arranged between the two stress components 200, the outer conductor layer 400 at least partially covers the electrode component 300, and there is a gap between the outer conductor layer 400 and the electrode component 300, and between the outer conductor layer 400 and the stress component 200.

[0138] S20, injecting an insulation material containing a ternary ethylene-propylene rubber into the gap between the outer conductor layer 400 and the electrode component 300, and the gap between the outer conductor layer 400 and the stress component 200 to vulcanize and form the insulation component 100, and the insulation component 100 connects the stress component 200, the electrode component 300, and the outer conductor layer 400.

[0139] S30, removing the support mold to form a joint channel penetrating the insulation component 100 in the axial direction.

[0140] In some embodiments, the insulation material is subjected to a mixing process before injection vulcanization molding, which includes internal mixing, open mixing, filtering, thin passing, and calendering. The insulation material is mixed according to a certain formula ratio to ensure that the product hardness and mechanical strength meet the injection vulcanization requirements.

[0141] It should be noted that the above-mentioned internal mixing (closed mixing) refers to the process of heating, shearing and mixing rubber or plastic in a closed mixing device. The device used for internal mixing is usually an internal mixer (Internal Mixer), such as a Banbury mixer. Internal mixing can achieve high mixing efficiency, good temperature control, and less dust, and is suitable for mass production.

[0142] Open mixing (open mixing) is a mixing process between two rollers rotating at different speeds. The device used for open mixing is an open mill (Two-roll Mill).

[0143] Filtering (filtering) refers to passing the mixed rubber through a screen or other filtering device to remove impurities, undispersed additive particles or gel blocks. Filtering is usually carried out in an extruder or a filter. The purpose of filtering is to improve the uniformity and quality of the product.

[0144] Thin passing refers to passing rubber between two rollers with very small spacing to form a thin sheet. The main purpose is to further uniform the temperature and structure of the rubber, improve the plasticity, and facilitate subsequent processing. Thin is usually carried out on an open mill.

[0145] Calendering is passing rubber or plastic through the gap between multiple heated rollers to press into a film or sheet with a certain thickness and width. The device used for calendering is a calender (Calender).

[0146] The mixture of ethylene propylene diene rubber, peroxide vulcanizing agent, reinforcing agent, filler, plasticizer, and stabilizer is subjected to internal mixing (preliminary mixing), open mixing (fine mixing), filtering (impurity removal), thin passing (temperature and structure adjustment), and calendering (forming a sheet / film) to obtain the insulation material, which can be used for injection vulcanization molding.

[0147] In some embodiments, the single internal mixing time is controlled to be not more than 10 min.

[0148] In some embodiments, the temperature of the insulation material after the mixing process is controlled to be no higher than 90°C. By controlling the mixing time and the temperature of the rubber, the ingredients of the insulation material are sufficiently mixed and uniform, and the scorching problem is avoided. It should be noted that the above-mentioned control of the temperature of the insulation material after the mixing process to be no higher than 90°C refers to the temperature at the middle position of the insulation material being no higher than 90°C.

[0149] In some embodiments, after the mixing process of the insulation material, the vulcanization test is performed on the insulation material, the tensile strength of the insulation material is > 5 MPa, the elongation is > 320%, the hardness is 55-65, and the compression permanent deformation is 8%-15%. After the test, if the above conditions are met, the product meets the production and use requirements. Through actual electrical test verification, the product withstand voltage margin reaches 1.6 times the standard value.

[0150] In one specific example, the parameters of the prefabricated intermediate joint assembly 10 are set as follows: the outer diameter D1 of the stress component 200 is 220 mm. The spherical radius R of the annular clamping groove closest to the inner wall of the joint channel is 100 mm. The distance L1 by which each second end portion 220 independently protrudes from the end surface of the insulation component 100 is 80 mm. The inner diameter D2 of the electrode component 300 is 130 mm, and the thickness W1 of the electrode component 300 is 20 mm. The thickness W2 of the outer conductor layer 400 is 5 mm. The length L2 of the prefabricated intermediate joint assembly 10 is 900 mm. The outer diameter D3 of the insulation component 100 is 250 mm. The minimum distance L3 between the stress component 200 and the electrode component 300 is 120 m. The obtained prefabricated intermediate joint assembly 10 is subjected to electric field simulation analysis. See Figure 4 Figure 4 Figure 1 is a schematic diagram of the electric field simulation of the prefabricated intermediate joint assembly 10 of an embodiment of the present application. The surface charge method (HSSSM) is used for electric field simulation analysis, and the dielectric constant of the ethylene propylene diene rubber is 2.7-3.5, and the dielectric constant of the XLPE cable 20 insulation is 2.1-2.5. According to the electric field analysis data, by adjusting the circular arc radius of the stress component 200, the distance between the stress component 200 and the electrode component 300, and the thickness of the insulation component 100, the interface field strength of the cable 20 and the stress component 200 and the internal field strength of the stress component 200 are optimally distributed, and the minimum field strength margin of the product design is > 1.3.

[0151] Example 1

[0152] The present embodiment provides an insulation material.

[0153] The insulation material comprises the following components by weight: ethylene propylene diene rubber 50; peroxide vulcanizing agent 3.5; reinforcing agent 1; plasticizer 11; stabilizer 2.5; and filler 30. ​

[0154] The insulation material is subjected to mixing treatment, which includes internal mixing, open mixing, filtering, thin passing and calendering. The single internal mixing time is controlled to be 8 min. The temperature of the insulation material after the mixing treatment is controlled to be 80℃. After the mixing treatment, the insulation material is subjected to vulcanization test. The tensile strength of the insulation material is 6.5 MPa, the elongation is 365%, the hardness is 58, and the compression permanent deformation is 12%.

[0155] Example 2

[0156] The present example provides an insulation material.

[0157] The insulation material includes the following components by weight: 30 of ethylene propylene diene monomer rubber; 2 of peroxide vulcanizing agent; 0.05 of reinforcing agent; 9 of plasticizer; 1 of stabilizer; and 25 of filler.

[0158] The insulation material is subjected to mixing treatment, which includes internal mixing, open mixing, filtering, thin passing and calendering. The single internal mixing time is controlled to be 8 min. The temperature of the insulation material after the mixing treatment is controlled to be 80℃. After the mixing treatment, the insulation material is subjected to vulcanization test. The tensile strength of the insulation material is 7.3 MPa, the elongation is 300%, the hardness is 65, and the compression permanent deformation is 8%.

[0159] Example 3

[0160] The present example provides an insulation material.

[0161] The insulation material includes the following components by weight: 40 of ethylene propylene diene monomer rubber; 2.5 of peroxide vulcanizing agent; 0.5 of reinforcing agent; 10 of plasticizer; 2 of stabilizer; and 28 of filler.

[0162] The insulation material is subjected to mixing treatment, which includes internal mixing, open mixing, filtering, thin passing and calendering. The single internal mixing time is controlled to be 8 min. The temperature of the insulation material after the mixing treatment is controlled to be 80℃. After the mixing treatment, the insulation material is subjected to vulcanization test. The tensile strength of the insulation material is 7 MPa, the elongation is 320%, the hardness is 61, and the compression permanent deformation is 9%.

[0163] Comparative Example 1

[0164] The present comparative example provides an insulation material.

[0165] The insulation material components of the present comparative example are basically the same as those of Example 1, except that the ethylene propylene diene monomer rubber in Comparative Example 1 is 60, i.e., the content of ethylene propylene diene monomer rubber is too large.

[0166] The insulation material was subjected to vulcanization test, and the tensile strength of the insulation material was 5.5 MPa, the elongation was 280%, the hardness was 53, and the compression permanent deformation was 15%.

[0167] Comparative Example 2

[0168] The present comparative example provides an insulation material.

[0169] The insulation material components of the present comparative example are basically the same as those of Example 1, except that the content of the peroxide vulcanizing agent in Comparative Example 2 is too small.

[0170] The insulation material was subjected to vulcanization test, and the tensile strength of the insulation material was 7.2 MPa, the elongation was 290%, the hardness was 68, and the compression permanent deformation was 10%.

[0171] Comparative Example 3

[0172] The present comparative example provides an insulation material.

[0173] The insulation material components of the present comparative example are basically the same as those of Example 1, except that the content of the peroxide vulcanizing agent in Comparative Example 3 is too large.

[0174] The insulation material was subjected to vulcanization test, and the tensile strength of the insulation material was 8 MPa, the elongation was 300%, the hardness was 56, and the compression permanent deformation was 11%.

[0175] Comparative Example 4

[0176] The present comparative example provides an insulation material.

[0177] The insulation material components of the present comparative example are basically the same as those of Example 1, except that the content of the peroxide vulcanizing agent in Comparative Example 4 is too small.

[0178] The insulation material was subjected to vulcanization test, and the tensile strength of the insulation material was 4.5 MPa, the elongation was 440%, the hardness was 51, and the compression permanent deformation was 18%.

[0179] Table 1 Comparison of test data of Example 1-Example 3 and Comparative Example 1-Comparative Example 4

[0180]

[0181] From the comparison of the test data of Examples 1-3 and Comparative Examples 1-4 in Table 1, it can be seen that in the insulating material of the present application, the content of the ethylene-propylene-diene rubber and the peroxide vulcanizing agent should not be too large or too small. When the content of the ethylene-propylene-diene rubber is too large, the material dispersion and uniformity become poor, and the strength and elongation become poor; when the content of the ethylene-propylene-diene rubber is too small, the rubber mixing effect becomes poor, the production efficiency and the performance of the rubber compound are reduced; when the content of the peroxide vulcanizing agent is too large, the rubber vulcanization speed is accelerated, the glue burning time is shortened, the heat resistance and elongation at break are reduced, which is not conducive to product production; when the content of the peroxide vulcanizing agent is too small, the rubber vulcanization speed is slowed down, the production efficiency, the tensile strength and the compression set performance are reduced, and the processing performance of the product is poor. In summary, in the present application, the content of the ethylene-propylene-diene rubber is 30-50, and the content of the peroxide vulcanizing agent is 2-3.5, which is the best.

[0182] In the present application, the injection molding performance of the material is improved by modifying the formula of the ethylene-propylene-diene rubber, which has excellent mechanical properties and aging resistance, and improves the processing performance of the rubber material. Through independent production, the manufacturing cost of the material is also reduced, and good economic benefits are obtained.

[0183] In summary, compared with the traditional technology, the present application has the following beneficial effects:

[0184] (1) Compared with the silicone rubber intermediate joint in the traditional technology, the present application successfully replaces the ethylene-propylene-diene rubber, solving the defects of poor tear resistance and overvoltage resistance of silicone rubber.

[0185] (2) Compared with the ethylene-propylene-diene rubber prepared from imported materials, the present application solves the problem of long-term dependence on imports in the field of ultra-high voltage, which brings the risk of supply and cost control due to the influence of international situation and upstream materials, and realizes the independent controllability of product raw materials.

[0186] (3) By analyzing and optimizing the product structure, the present application can cover the application voltage level of 66kV-500kV or above for the whole prefabricated ethylene-propylene-diene rubber intermediate joint, realizing the breakthrough of the application of domestic whole prefabricated ethylene-propylene-diene rubber intermediate joint in the field of ultra-high voltage.

[0187] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0188] Each technical feature of the above-described embodiments can be combined arbitrarily, and in order to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0189] The above-described embodiments are merely illustrative of several embodiments of the present application, which are described in more detail and in a more specific and detailed manner, but should not be construed as limiting the scope of the patent of the present application. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An insulating material, characterized in that, The insulating material comprises ethylene propylene terpolymer, peroxide vulcanizing agent, reinforcing agent, filler, plasticizer and stabilizer, and each component satisfies the following weight ratio: Ethylene propylene terpolymer 30~50; Peroxide vulcanizing agent 2~3.5; Reinforcing agent 0.05~1; Plasticizer 9~11; Stabilizer 1~2.5; Filler 25~30; Optionally, the peroxide vulcanizing agent comprises peroxide ester; Further optionally, the peroxide ester comprises one or more of dicumyl peroxide, dibenzoyl peroxide and benzoyl peroxide; Optionally, the reinforcing agent comprises one or more of carbon black, silane coupling agent and calcium carbonate; Optionally, the plasticizer comprises one or more of paraffin oil, naphthenic oil and stearic acid; Optionally, the stabilizer comprises one or more of antioxidant and antidegradant; Optionally, the filler comprises one or more of kaolin, calcium carbonate and talc.

2. A preformed intermediate joint assembly, characterized by The preformed intermediate joint assembly comprises an insulating component, a stress component, an electrode component and an outer conductor layer, the insulating component is provided with a joint channel along its axial direction, the stress component is connected to each end of the joint channel, each stress component protrudes from the corresponding end face of the insulating component, the inner wall of the joint channel is connected to the electrode component, and the outer conductor layer is connected to the outer wall of the insulating component, wherein the insulating component is formed by injection vulcanization using the insulating material of claim 1.

3. The pre-fabricated intermediate joint assembly of claim 2, wherein, The preformed intermediate joint assembly further satisfies at least one of the following conditions: (1) the stress component has electrically conductive or semi-conductive capability; (2) the stress component has a ring structure, the insulating component is provided with a ring-shaped clamping groove around the joint channel at each end face along the joint channel, and each stress component is embedded in the corresponding clamping groove; Optionally, the stress component has a whole ring structure; Further optionally, the inner wall of the stress component is flush with the inner wall of the joint channel; Further optionally, the outer diameter D1 of the stress component is 200mm~250mm.

4. The pre-fabricated intermediate joint assembly of claim 3, wherein, The inner wall of the stress component closest to the joint channel gradually narrows from the groove opening to the groove bottom face, the stress component comprises opposite first and second end portions, the inner wall of the first end portion gradually expands outward from the direction close to the second end portion to the direction away from the second end portion to adapt to the ring-shaped clamping groove, and the first end portion is embedded in the ring-shaped clamping groove.

5. The pre-fabricated intermediate joint assembly of claim 4, wherein, The preformed intermediate joint assembly further satisfies at least one of the following conditions: (1) the inner wall of the ring-shaped clamping groove closest to the joint channel is curvedly narrowed; Optionally, the inner wall of the ring-shaped clamping groove closest to the joint channel is spherically narrowed; Further optionally, the spherical radius R of the inner wall of the ring-shaped clamping groove closest to the joint channel is 90mm~120mm; (2) the inner wall of the ring-shaped clamping groove closest to the joint channel gradually narrows from the groove opening to the groove bottom face to the inner wall farthest from the joint channel.

6. The pre-fabricated intermediate joint assembly of claim 4, wherein, The preformed intermediate joint assembly further satisfies at least one of the following conditions: (1) The second end portion independently protrudes from the end surface of the insulating component by a distance L1 of 20 mm to 80 mm; (2) The second end portion has a boss structure.

7. The preformed intermediate joint assembly of any of claims 2-6, wherein, The prefabricated intermediate joint assembly further satisfies at least one of the following conditions: (1) The electrode component has a ring structure; Optionally, the electrode component is embedded in the inner wall of the joint channel, and the inner wall of the electrode component is flush with the inner wall of the joint channel; Optionally, the electrode component has a circular ring structure; Further optionally, the inner diameter D2 of the electrode component is 90 mm to 120 mm; Further optionally, the thickness W1 of the electrode component is 5 mm to 40 mm; (2) The outer conductor layer has a ring structure; Optionally, the outer conductor layer is embedded in the outer wall of the insulating component, and the outer wall of the outer conductor layer is flush with the outer wall of the insulating component; Optionally, the outer conductor layer has a circular ring structure; Further optionally, the thickness W2 of the outer conductor layer is 5 mm to 20 mm.

8. The preformed intermediate joint assembly of any of claims 2-6, wherein, The prefabricated intermediate joint assembly further satisfies at least one of the following conditions: (1) Along the axial direction of the insulating component, the length L2 of the prefabricated intermediate joint assembly is 800 mm to 1000 mm; (2) The insulating component has a cylindrical structure as a whole, and the outer diameter D3 of the insulating component is 200 mm to 300 mm; (3) Along the axial direction of the insulating component, the minimum distance L3 between the stress component and the electrode component is 100 mm to 150 mm.

9. A method of making a preformed intermediate joint assembly, characterized by, The method comprises the following steps: The stress component, the electrode component, and the outer conductor layer are respectively arranged at predetermined positions on a support mold, wherein the two stress components are arranged at intervals, the electrode component is arranged between the two stress components, the outer conductor layer at least partially covers the electrode component, and there is a gap between the outer conductor layer and the electrode component and between the outer conductor layer and the stress component; An insulating material containing ethylene-propylene-diene rubber is injected into the gap between the outer conductor layer and the electrode component and the gap between the outer conductor layer and the stress component to form an insulating component by vulcanization molding, and the insulating component connects the stress component, the electrode component, and the outer conductor layer; And the support mold is removed to form a joint channel penetrating in the axial direction of the insulating component.

10. The method of claim 9, wherein the method further comprises: The preparation method of the prefabricated intermediate joint assembly satisfies at least one of the following conditions: (1) The insulating material comprises ethylene-propylene-diene rubber, peroxide vulcanizing agent, reinforcing agent, filler, plasticizer, and stabilizer, and each component satisfies the following weight ratio: Ethylene-propylene-diene rubber 30-50; Peroxide vulcanizing agent 2-3.5; Reinforcing agent 0.05-1; Plasticizer 9-11; Stabilizer 1-2.5; And filler 25-30; Optionally, the peroxide vulcanizing agent comprises peroxide ester; Further optionally, the peroxide ester comprises one or more of dicumyl peroxide, dibenzoyl peroxide, and benzoyl peroxide; Optionally, the reinforcing agent comprises one or more of carbon black, silane coupling agent, and calcium carbonate; Optionally, the plasticizer comprises one or more of paraffin oil, naphthenic oil and stearic acid; Optionally, the stabilizer comprises one or more of antioxidant and anti-aging agent; Optionally, the filler comprises one or more of kaolin, calcium carbonate and talcum powder; (2) before injection vulcanization molding, the insulation material is subjected to mixing treatment, the mixing treatment comprises banburying, open rolling, filtering, thin passing and calendering; Optionally, the single banburying time is controlled to be no more than 10 min; Optionally, the temperature of the insulation material after mixing treatment is controlled to be no higher than 90℃; (3) after the mixing treatment of the insulation material, the insulation material is subjected to vulcanization test, the tensile strength of the insulation material is > 5 MPa, the elongation is > 320%, the hardness is 55~65, and the compression permanent deformation is 8%~15%.

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