Conductive sealing materials for cable cores and their preparation methods, cable accessories

Abstract

This invention discloses a conductive sealing material for cable cores, comprising the following raw materials by weight: 100 parts of base rubber, 1-3 parts of heat resistant agent, 1-2 parts of antioxidant, 80-120 parts of plasticizer, 50-100 parts of tackifier, and 80-120 parts of carbon black, wherein the heat resistant agent is zinc oxide. This invention also discloses a method for preparing this material and cable accessories. By adding the heat resistant agent, antioxidant, plasticizer, and tackifier, the conductive sealing material effectively coats and adheres to the outside of the cable accessory conductor, providing a shielding effect and preventing water or moisture from entering the cable accessory and causing creepage breakdown. This ensures the normal and stable operation of the cable accessory even in the presence of water. Furthermore, the addition of carbon black enhances the conductivity of the conductive sealing material, improving electric field distortion when used in the shielding area of ​​the cable accessory conductor, especially providing better shielding for irregular conductors, thereby ensuring the normal and stable operation of the cable accessory.

Description

Technical Field

[0001] This invention relates to the field of sealant technology, and in particular to a conductive sealing material for cable cores, its preparation method, and cable accessories. Background Technology

[0002] Power cable lines are a crucial component of power systems. To ensure safe and reliable operation, cables must be kept sealed, and the insulation level at cable joints must be maintained. However, during cable laying, handling, and installation of cable accessories, improper handling and protection can damage the cable sheath, or result in inadequate sealing at cable joints. When cables are exposed to rain or immersion in external water, water can seep into the cable through damaged areas or cuts at joints, causing water ingress and posing a serious threat to the safe operation of the cable and its accessories. Once water enters the cable core, when the cable is energized, water or water vapor can penetrate the interface between the cable insulation and cable accessories, causing creepage breakdown along the cable insulation surface at intermediate joints or terminals. This severely affects the safe and stable operation of the cable and its accessories, posing a significant safety hazard, especially to intermediate joints.

[0003] While commonly used waterproof sealing materials in existing technologies offer some waterproofing, they are insulating materials. When used on cable conductors, especially in shielded areas, they can cause the shielding material to lose its shielding effect, leading to localized electric field distortion and potentially causing cable accessory breakdown. This can affect the long-term stable and safe operation of the cable and its accessories, making them unsuitable as waterproofing materials for cable conductors. Furthermore, while commonly used semi-conductive self-adhesive tapes offer conductive shielding, they do not adhere well to the cable conductors and insulation, resulting in poor sealing. This allows water or moisture to penetrate the cable accessories along the interface, making it difficult to eliminate the risk of creepage breakdown along the cable insulation surface at cable joints or terminals.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this invention is to provide a conductive sealing material for cable cores and its preparation method, as well as cable accessories, which aims to eliminate the potential risk of creepage breakdown along the cable insulation surface at cable joints or terminals.

[0006] To achieve the above objectives, the present invention provides a conductive sealing material for cable cores, which comprises the following raw materials in parts by weight:

[0007] The composition includes 100 parts of base rubber, 1-3 parts of heat resistant agent, 1-2 parts of antioxidant, 80-120 parts of plasticizer, 50-100 parts of tackifier, and 80-120 parts of carbon black, wherein the heat resistant agent is zinc oxide.

[0008] Optionally, the body rubber is one or more of ethylene propylene rubber, butyl rubber, and silicone rubber.

[0009] Optionally, the antioxidant is one or both of 2,2,4-trimethyl-1,2-dihydroquinoline polymer and 2-thiol-benzimidazole.

[0010] Optionally, the plasticizer is one or more of leucocyclohexane oil, transformer oil, paraffin oil, polyisobutylene, dioctyl sebacate, and liquid polybutadiene; the tackifier is one or more of phenolic resin, rosin resin, coumarone resin, and terpene resin.

[0011] Optionally, the carbon black is one or more of acetylene black, carbon black, and channel black.

[0012] Furthermore, to achieve the above objectives, the present invention also provides a method for preparing a conductive sealing material for cable cores. This method is used to prepare the aforementioned conductive sealing material for cable cores, and the method includes the following steps:

[0013] The first rubber compound is obtained by kneading 100 parts of the base rubber, 1-3 parts of heat resistant agent and 1-2 parts of antioxidant using a kneader;

[0014] Add 50-80 parts of tackifier, 80-120 parts of plasticizer and 80-120 parts of carbon black to the first rubber compound, and knead and mix them in a kneader to obtain the second rubber compound;

[0015] After the second rubber compound is thoroughly mixed using a kneader, it is extruded using a rubber extruder to obtain the conductive sealing material for the cable core.

[0016] Optionally, the temperature at which the first rubber compound is kneaded is room temperature, and the kneading time for obtaining the first rubber compound is 15 to 25 minutes;

[0017] The temperature at which the second rubber compound is obtained by kneading is 95–105°C.

[0018] Optionally, the 50-80 parts of tackifier includes a first part of tackifier, a second part of tackifier and a third part of tackifier, the 80-120 parts of carbon black includes a fourth part of carbon black, a fifth part of carbon black and a sixth part of carbon black, and the 80-120 parts of plasticizer includes a seventh part of plasticizer and an eighth part of plasticizer;

[0019] The step of adding 50-80 parts of tackifier, 80-120 parts of plasticizer, and 80-120 parts of carbon black to the first rubber compound, and kneading and mixing it in a kneader to obtain the second rubber compound includes:

[0020] The first part of tackifier and the fourth part of carbon black are added to the first rubber compound, and the mixture is kneaded and mixed in a kneader to obtain the first intermediate material.

[0021] The second part of the thickener, the fifth part of the carbon black, and the seventh part of the plasticizer are added to the first intermediate material, and the mixture is kneaded and mixed using a kneader to obtain the second intermediate material.

[0022] The third part of the tackifier, the sixth part of the carbon black, and the eighth part of the plasticizer are added to the second intermediate material, and the mixture is kneaded and mixed using a kneader to obtain the second rubber compound.

[0023] Optionally, the temperature at which the first intermediate material is kneaded is 95–105°C, and the kneading time for obtaining the first intermediate material is 15–25 min;

[0024] The temperature at which the second intermediate material is obtained by kneading is 95–105°C, and the kneading time is 15–25 min.

[0025] The temperature at which the second rubber compound is obtained by kneading is 95–105°C, and the kneading time is 25–35 minutes.

[0026] In addition, to achieve the above objectives, the present invention also provides a cable accessory, wherein the outer surface of the conductor connection of the cable accessory is covered with the conductive sealing material of the cable core as described above.

[0027] This invention proposes a conductive sealing material for cable cores, which comprises the following raw materials by weight: 100 parts of body rubber, 1-3 parts of heat resistant agent, 1-2 parts of antioxidant, 80-120 parts of plasticizer, 50-100 parts of tackifier, and 80-120 parts of carbon black, wherein the heat resistant agent is zinc oxide.

[0028] In this invention, the heat resistance of the conductive sealing material of the cable core is improved by adding a heat-resistant agent, the aging performance of the conductive sealing material of the cable core is improved by adding an anti-aging agent, and the flexibility and field performance of the conductive sealing material of the cable core are improved by adding a plasticizer.

[0029] By adding tackifiers, the adhesion performance between the conductive sealing material of the cable core and other materials is improved. The tackifier and plasticizer work synergistically to make the conductive sealing material of the cable core bond tightly to the conductor, the semi-conductive shielding material or insulation layer at the joint, and prevent water or moisture from entering the cable accessories and causing creepage breakdown. This ensures that the cable accessories can still operate normally and stably even if water enters.

[0030] By adding carbon black, the conductivity of the conductive sealing material of the cable core is improved, which can improve the electric field distortion when the conductive sealing material of the cable core is used for conductor shielding of cable accessories. In particular, the shielding effect is better for irregular conductors, thereby ensuring the normal and stable operation of cable accessories.

[0031] Furthermore, the conductive sealing material for cable cores provided by this invention has a simple preparation method, requires no vulcanization reaction, and can improve the reliability of cable accessory operation when applied to conductor connections. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of an embodiment of the method for preparing conductive sealing material for cable cores according to the present invention;

[0033] Figure 2 This is a schematic flowchart of an embodiment of the method for preparing conductive sealing material for cable cores according to the present invention.

[0034] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0035] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0036] This invention provides a conductive sealing material for cable cores. In this embodiment, the conductive sealing material for cable cores includes the following raw materials: 100 parts of body rubber, 1-3 parts of heat resistant agent, 1-2 parts of antioxidant, 80-120 parts of plasticizer, 50-100 parts of tackifier, and 80-120 parts of carbon black, wherein the heat resistant agent is zinc oxide.

[0037] In this embodiment, the body rubber is the main molding body of the conductive sealing material for the cable core in this embodiment.

[0038] In this embodiment, zinc oxide, as a heat-resistant agent, can improve the weather resistance of the conductive sealing material of the cable core, making the conductive sealing material of the cable core less prone to thermal aging.

[0039] In this embodiment, the antioxidant is used to delay the aging of rubber. At the same time, the antioxidant used together with zinc oxide can improve the aging performance of the conductive sealing material of the cable core, thereby extending the service life of the conductive sealing material of the cable core.

[0040] In this embodiment, the plasticizer is used to enhance the flexibility of the conductive sealing material of the cable core, increase its field performance, and ensure good adhesion of the conductive sealing material to the shielding part of the cable core conductor. This prevents water or moisture from entering the cable accessory and causing creepage breakdown along the cable insulation surface at the cable joint or terminal, thus ensuring the normal and stable operation of the cable accessory even in the presence of water. Furthermore, during the mixing of the conductive sealing material, the plasticizer promotes the dispersion of fillers and other additives, improves the extrusion performance of the compound, and enhances the smoothness of the finished conductive sealing material.

[0041] In this embodiment, the tackifier wets the bonding surface through surface or internal diffusion, thereby increasing the bonding strength between the conductive sealing material of the cable core and the bonded material. In this embodiment, by using the tackifier to increase the adhesion between the conductive sealing material of the cable core and the semiconducting shielding layer and insulation layer at the cable joint cut, the conductive sealing material of the cable core at the cable interface is tightly connected to the cable cut, preventing water or moisture from entering the cable accessories.

[0042] In this embodiment, carbon black is used as a conductive material, which allows the conductive sealing material of the cable core to wrap the cable interface, thereby uniformly distributing the electric field of the conductor and improving the shielding effect on the cable conductor. In particular, it can improve the electric field distortion at the sharp corner cut of the cable interface, thus ensuring the normal operation of the cable accessories.

[0043] Furthermore, in some feasible embodiments, the body rubber is one or more of ethylene propylene rubber, butyl rubber, and silicone rubber.

[0044] Specifically, ethylene propylene rubber has excellent resistance to ozone, heat, and weathering, as well as good chemical resistance, electrical insulation, impact elasticity, low-temperature performance, low density, high filling capacity, hot water resistance, and water vapor resistance. This can prevent water or water vapor from entering the cable accessories and causing creepage breakdown along the cable insulation surface at the cable joints or terminals, thus ensuring the normal and stable operation of the cable accessories even in the presence of water.

[0045] Butyl rubber has good chemical resistance, weather resistance and aging resistance, which makes the conductive sealing material of the cable core less prone to damage during use. It prevents water or moisture from entering the inside of the cable accessories and causing creepage breakdown along the cable insulation surface at the cable joint or terminal, so that the cable accessories can still operate normally and stably even in the presence of water.

[0046] Silicone rubber has good heat resistance and aging resistance, which makes the conductive sealing material of the cable core less prone to damage during use. It prevents water or moisture from entering the inside of the cable accessories and causing creepage breakdown along the cable insulation surface at the cable joint or terminal, thus ensuring the normal and stable operation of the cable accessories even in the presence of water.

[0047] Furthermore, in some feasible embodiments, the antioxidant is one or both of 2,2,4-trimethyl-1,2-dihydroquinoline polymer and 2-thiol-benzimidazole.

[0048] Furthermore, in some feasible embodiments, the plasticizer is one or more of leucycloalkane oil, transformer oil, paraffin oil, polyisobutylene, dioctyl sebacate, and liquid polybutadiene.

[0049] Specifically, paraffin oil has low aromatic content and low volatility. Low aromatic content can improve the antioxidant degradation performance of conductive sealing materials for cable cores and provide better weather resistance. Low volatility helps prevent aging and shrinkage of conductive sealing materials for cable cores and makes the finished conductive sealing materials for cable cores smooth.

[0050] Polyisobutylene has good compatibility with polymer materials, which can improve the plasticity, viscosity and extensibility of conductive sealing materials for cable cores, making them more flexible and improving their wear resistance.

[0051] Dioctyl sebacate can provide cable core conductive sealing materials with cold resistance, heat resistance, light resistance and electrical insulation. In addition, dioctyl sebacate has good lubricity, which can make the finished cable core conductive sealing material products smooth.

[0052] Liquid polybutadiene can improve the plasticity, viscosity, and extensibility of conductive sealing materials for cable cores, making them more flexible and improving their wear resistance.

[0053] Furthermore, in some feasible embodiments, the tackifier is one or more of phenolic resin, rosin resin, coumarone resin, and terpene resin.

[0054] Specifically, phenolic resin has strong adhesion, high heat resistance, good aging resistance, water resistance, oil resistance, chemical resistance, and mildew resistance. It can enhance the adhesion between the conductive sealing material of the cable core and the semiconducting shielding layer and insulation layer at the cable joint cut. At the same time, it can also make the conductive sealing material of the cable core less prone to damage, ensuring a tight connection between the conductive sealing material of the cable core and the cable cut at the cable interface, preventing water or moisture from entering the cable accessories.

[0055] Coumarone resin significantly improves the adhesion of conductive sealant materials for cable cores and enhances their abrasion resistance, tensile strength, and aging resistance. It improves the adhesion between the conductive sealant and the semi-conductive shielding and insulation layers at the cable joint cut, while also making the sealant less prone to damage. This ensures a tight bond between the sealant and the cable joint, preventing water or moisture from entering the cable accessories.

[0056] Terpene resins possess strong adhesive properties, as well as excellent heat resistance, radiation protection, acid and alkali resistance, aging resistance, and dielectric properties. They enhance the adhesion between the conductive sealing material of the cable core and the semiconducting shielding and insulation layers at the cable joint cut. Simultaneously, they prevent the conductive sealing material of the cable core from being damaged, ensuring a tight connection between the conductive sealing material of the cable core and the cable cut at the cable interface, thus preventing water or moisture from entering the cable accessories.

[0057] Furthermore, in some feasible embodiments, the carbon black is one or more of acetylene black, conductive carbon black, and channel black. Preferably, the carbon black is conductive carbon black, which has the best conductivity. In other embodiments, the carbon black is a composite of acetylene black and conductive carbon black, a composite of channel black and conductive carbon black, or a composite of acetylene black, conductive carbon black, and channel black, to balance conductivity and cost.

[0058] In this embodiment, the conductive sealing material for the cable core comprises the following raw materials by weight: 100 parts of body rubber, 1-3 parts of heat resistant agent, 1-2 parts of antioxidant, 80-120 parts of plasticizer, 50-100 parts of tackifier, and 80-120 parts of carbon black.

[0059] In this embodiment, the heat resistance of the cable core conductive sealing material is improved by adding a heat-resistant agent, the aging performance of the cable core conductive sealing material is improved by adding an anti-aging agent, and the flexibility and field performance of the cable core conductive sealing material are improved by adding a plasticizer.

[0060] By adding tackifiers, the adhesion performance between the conductive sealing material of the cable core and other materials is improved. The tackifier and plasticizer work synergistically to make the conductive sealing material of the cable core bond tightly to the conductor, the semi-conductive shielding material or insulation layer at the joint, and prevent water or moisture from entering the cable accessories and causing creepage breakdown. This ensures that the cable accessories can still operate normally and stably even if water enters.

[0061] By adding carbon black, the conductivity of the conductive sealing material of the cable core is improved, which can improve the electric field distortion when the conductive sealing material of the cable core is used for conductor shielding of cable accessories. In particular, the shielding effect is better for irregular conductors, thereby ensuring the normal and stable operation of cable accessories.

[0062] Furthermore, the conductive sealing material for cable cores provided in this embodiment is simple to prepare, requires no vulcanization reaction, and can improve the reliability of cable accessories when applied to conductor connections.

[0063] Based on the above-mentioned conductive sealing material for cable cores, a method for preparing the cable core material according to an embodiment of the present invention is proposed. Specifically, refer to... Figure 1 , Figure 1 This is a schematic flowchart of an embodiment of the method for preparing conductive sealing material for cable cores according to the present invention. In this embodiment, the method for preparing cable cores includes:

[0064] Step S10: Use a kneader to knead 100 parts of the base rubber, 1-3 parts of heat resistant agent and 1-2 parts of antioxidant to obtain the first rubber compound;

[0065] In this embodiment, 100 parts of the main body rubber, 1 to 3 parts of heat resistant agent and 1 to 2 parts of antioxidant are added to a kneader and kneaded. The resulting rubber compound is referred to as the first rubber compound for distinction.

[0066] Step S20: Add 50-80 parts of tackifier, 80-120 parts of plasticizer and 80-120 parts of conductive carbon black to the first rubber compound, and knead and mix them using a kneader to obtain the second rubber compound;

[0067] Add 50-80 parts of tackifier, 80-120 parts of plasticizer and 80-120 parts of conductive carbon black to the first rubber compound, and knead and mix it using a kneader. The rubber compound obtained by kneading is called the second rubber compound to distinguish it.

[0068] Step S30: After the second rubber compound is thoroughly mixed using a kneader, the mixed second rubber compound is extruded using a rubber extruder to obtain the conductive sealing material for the cable core.

[0069] Specifically, in this embodiment, after the second rubber compound is thoroughly mixed using a kneader, the mixed second rubber compound is extruded using a rubber extruder to obtain sheet-like putty, which is the conductive sealing material for cable cores.

[0070] Furthermore, in some feasible embodiments, the temperature at which the first rubber compound is kneaded is room temperature, the kneading time for the first rubber compound is 15 to 25 minutes, and the temperature at which the second rubber compound is kneaded is 95 to 105°C.

[0071] Furthermore, in one embodiment, the kneading time to obtain the first rubber compound can be 20 minutes, and the kneading temperature to obtain the second rubber compound can be 100°C.

[0072] In this embodiment, the temperature of kneading the second rubber compound is 95-105°C, which helps to disperse various additives in the first rubber compound and makes each additive dispersed evenly.

[0073] Furthermore, in some feasible embodiments, 50-80 parts of tackifier includes a first part, a second part, and a third part of tackifier; 80-120 parts of carbon black includes a fourth part, a fifth part, and a sixth part of carbon black; and 80-120 parts of plasticizer includes a seventh part and an eighth part of plasticizer. In specific embodiments, the specific proportions of the first, second, and third parts of tackifier, the fourth, fifth, and sixth parts of carbon black, and the seventh and eighth parts of plasticizer can be set according to actual needs.

[0074] Further, in one embodiment, the first part of the tackifier may be 20-30% of the total tackifier content, the second part of the tackifier may be 20-30% of the total tackifier content, the third part of the tackifier may be 40-60% of the total tackifier content, the fourth part of the carbon black may be 20-30% of the total carbon black content, the fifth part of the carbon black may be 20-30% of the total carbon black content, the sixth part of the carbon black may be 40-60% of the total carbon black content, and the seventh part of the plasticizer may be 40-60% of the total plasticizer content, and the eighth part of the plasticizer may be 40-60% of the total plasticizer content. Preferably, the first part of the tackifier can be 30% of the total tackifier content, the second part of the tackifier can be 30% of the total tackifier content, the third part of the tackifier can be 40% of the total tackifier content, the fourth part of the carbon black can be 30% of the total carbon black content, the fifth part of the carbon black can be 30% of the total carbon black content, the sixth part of the carbon black can be 40% of the total carbon black content, the seventh part of the plasticizer can be 40% of the total plasticizer content, and the eighth part of the plasticizer can be 60% of the total plasticizer content.

[0075] Specifically, refer to Figure 2 , Figure 2 This is a schematic flowchart of an embodiment of the method for preparing conductive sealing material for cable cores according to the present invention. In this embodiment, step S20 includes:

[0076] Step S201: Add the first part of tackifier and the fourth part of carbon black to the first rubber compound, and knead and mix them using a kneader to obtain the first intermediate material;

[0077] In this embodiment, a first part of tackifier and a fourth part of carbon black are added to the first rubber compound, and the compound is kneaded and mixed using a kneader. The intermediate rubber compound obtained by the mixing is called the first intermediate material.

[0078] Step S202: Add the second part of the thickener, the fifth part of the carbon black and the seventh part of the plasticizer to the first intermediate material, and knead and mix them using a kneader to obtain the second intermediate material;

[0079] Add a second part of tackifier, a fifth part of carbon black, and a seventh part of plasticizer to the first intermediate material, and knead and mix them using a kneader. The intermediate rubber compound obtained by the kneading is called the second intermediate material.

[0080] Step S203: Add the third part of the tackifier, the sixth part of the carbon black and the eighth part of the plasticizer to the second intermediate material, and knead and mix them using a kneader to obtain the second rubber compound.

[0081] Add a third part of tackifier, a sixth part of carbon black, and an eighth part of plasticizer to the second intermediate material, and knead and mix them using a kneader to obtain the second rubber compound.

[0082] In this embodiment, 50-80 parts of plasticizer, 80-120 parts of tackifier and 80-120 parts of carbon black are added to the first rubber compound in multiple batches for kneading and mixing, so that the plasticizer, tackifier and carbon black can be mixed evenly in the rubber compound.

[0083] Furthermore, in some feasible embodiments, the temperature for kneading to obtain the first intermediate material is 95–105°C, and the kneading time for obtaining the first intermediate material is 15–25 minutes. Specifically, in one embodiment, the temperature for kneading to obtain the first intermediate material can be 100°C, and the kneading time for obtaining the first intermediate material can be 20 minutes.

[0084] In this embodiment, the temperature at which the second intermediate material is kneaded is 95–105°C, and the kneading time is 15–25 minutes. Specifically, in one embodiment, the temperature at which the second intermediate material is kneaded is 100°C, and the kneading time is 20 minutes.

[0085] In this embodiment, the temperature at which the second rubber compound is kneaded is 95-105°C, and the kneading time is 25-35 minutes. Specifically, in one embodiment, the temperature at which the second rubber compound is kneaded can be 100°C, and the kneading time can be 30 minutes.

[0086] In this embodiment, the heat resistance of the cable core conductive sealing material is improved by adding a heat-resistant agent, the aging performance of the cable core conductive sealing material is improved by adding an anti-aging agent, and the flexibility and field performance of the cable core conductive sealing material are improved by adding a plasticizer.

[0087] By adding tackifiers, the adhesion performance between the conductive sealing material of the cable core and other materials is improved. The tackifier and plasticizer work synergistically to make the conductive sealing material of the cable core bond tightly to the conductor, the semi-conductive shielding material or insulation layer at the joint, and prevent water or moisture from entering the cable accessories and causing creepage breakdown. This ensures that the cable accessories can still operate normally and stably even if water enters.

[0088] By adding carbon black, the conductivity of the conductive sealing material of the cable core is improved, which can improve the electric field distortion when the conductive sealing material of the cable core is used for conductor shielding of cable accessories. In particular, the shielding effect is better for irregular conductors, thereby ensuring the normal and stable operation of cable accessories.

[0089] Furthermore, the conductive sealing material for cable cores provided in this embodiment is simple to prepare, requires no vulcanization reaction, and can improve the reliability of cable accessory operation when applied to conductor connections.

[0090] The present invention will be further described in detail below with reference to specific embodiments. Referring to Table 1, which shows the raw material composition of some feasible embodiments of the present invention, the following detailed description will be based on Table 1.

[0091] Table 1 Raw material composition of each embodiment

[0092]

[0093] In Table 1, antioxidant RD is 2,2,4-trimethyl-1,2-dihydroquinoline polymer, and antioxidant MB is 2-thiol-benzimidazole. " / " indicates that this ingredient was not added.

[0094] Example 1

[0095] This embodiment prepares a conductive sealing material for cable cores. The raw material formula is shown in Example 1 of Table 1. The specific preparation steps are as follows:

[0096] The first rubber compound was obtained by kneading 10 parts of ethylene propylene rubber, 70 parts of butyl rubber and 20 parts of silicone rubber, 1 part of zinc oxide and 1 part of RD antioxidant at room temperature for 20 minutes using a kneader.

[0097] Add 30 parts of coumarone resin and 30 parts of rosin resin, 40 parts of white naphthenic oil, 30 parts of transformer oil and 20 parts of paraffin oil, as well as 80 parts of acetylene black and 40 parts of conductive black to the first rubber compound, heat to 100°C, and knead and mix using a kneader to obtain the second rubber compound.

[0098] After the second rubber compound is thoroughly mixed using a kneader, it is extruded using a rubber extruder to form a conductive sealing material for the cable core.

[0099] Example 2

[0100] This embodiment prepares a conductive sealing material for cable cores. The raw material formula is shown in Example 2 of Table 1. The specific preparation steps are as follows:

[0101] The first rubber compound was obtained by kneading 10 parts of ethylene propylene rubber, 90 parts of butyl rubber, 2 parts of zinc oxide, 1 part of RD antioxidant and 1 part of MB antioxidant at room temperature for 20 minutes.

[0102] Add 30 parts of coumarone resin, 30 parts of rosin resin and 20 parts of phenolic resin, 40 parts of white naphthenic oil, 20 parts of transformer oil and 30 parts of polyisobutylene, 70 parts of acetylene black and 50 parts of conductive black to the first rubber compound, heat to 100°C, and knead and mix using a kneader to obtain the second rubber compound.

[0103] After the second rubber compound is thoroughly mixed using a kneader, it is extruded using a rubber extruder to form a conductive sealing material for the cable core.

[0104] Example 3

[0105] This embodiment prepares a conductive sealing material for cable cores. The raw material formula is shown in Example 3 of Table 1. The specific preparation steps are as follows:

[0106] The first rubber compound was obtained by kneading 10 parts of ethylene propylene rubber, 90 parts of butyl rubber, 3 parts of zinc oxide, 1 part of RD antioxidant and 1 part of MB antioxidant at room temperature for 20 minutes.

[0107] Add 20 parts of coumarone resin, 20 parts of rosin resin, 30 parts of phenolic resin, 30 parts of leucycloalkane oil, 20 parts of paraffin oil, 30 parts of polyisobutylene, 20 parts of dioctyl sebacate, 60 parts of acetylene black, and 60 parts of conductive carbon black to the first rubber compound, heat to 100°C, and knead and mix using a kneader to obtain the second rubber compound.

[0108] After the second rubber compound is thoroughly mixed using a kneader, it is extruded using a rubber extruder to form a conductive sealing material for the cable core.

[0109] Example 4

[0110] This embodiment prepares a conductive sealing material for cable cores. The raw material formula is shown in Example 4 of Table 1. The specific preparation steps are as follows:

[0111] The first rubber compound was obtained by kneading 90 parts butyl rubber, 10 parts silicone rubber, 1 part zinc oxide and 1 part MB antioxidant using a kneader at room temperature for 20 minutes.

[0112] Add 30 parts of rosin resin, 30 parts of phenolic resin and 20 parts of terpene resin, 20 parts of leucycloalkane oil, 30 parts of transformer oil, 30 parts of polyisobutylene, 10 parts of dioctyl sebacate and 30 parts of liquid polybutadiene, as well as 40 parts of acetylene black, 60 parts of conductive black and 20 parts of channel black to the first rubber compound, heat to 100°C, and knead and mix using a kneader to obtain the second rubber compound.

[0113] After the second rubber compound is thoroughly mixed using a kneader, it is extruded using a rubber extruder to form a conductive sealing material for the cable core.

[0114] Example 5

[0115] This embodiment prepares a conductive sealing material for cable cores. The raw material formula is shown in Example 5 of Table 1. The specific preparation steps are as follows:

[0116] The first rubber compound was obtained by kneading 20 parts of ethylene propylene rubber, 80 parts of butyl rubber, 2 parts of zinc oxide, and 1 part of MB antioxidant using a kneader and kneading at room temperature for 20 minutes.

[0117] Add 20 parts of rosin resin, 30 parts of phenolic resin and 20 parts of terpene resin, 40 parts of leucycloalkane oil, 20 parts of paraffin oil, 40 parts of polyisobutylene and 10 parts of dioctyl sebacate, as well as 30 parts of acetylene black, 60 parts of conductive black and 30 parts of channel black to the first rubber compound, heat to 100°C, and knead and mix using a kneader to obtain the second rubber compound.

[0118] After the second rubber compound is thoroughly mixed using a kneader, it is extruded using a rubber extruder to form a conductive sealing material for the cable core.

[0119] Example 6

[0120] This embodiment prepares a conductive sealing material for cable cores. The raw material formula is shown in Example 5 of Table 1. The specific preparation steps are as follows:

[0121] The first rubber compound was obtained by kneading 10 parts of ethylene propylene rubber, 70 parts of butyl rubber, 20 parts of silicone rubber, 1 part of zinc oxide, and 1 part of RD antioxidant at room temperature for 20 minutes using a kneader.

[0122] Add 30 parts of coumarone resin and 30 parts of rosin resin, 40 parts of white naphthenic oil, 30 parts of transformer oil and 20 parts of liquid polybutadiene, as well as 30 parts of acetylene black, 60 parts of conductive black and 30 parts of channel black to the first rubber compound, heat to 100°C, and knead and mix using a kneader to obtain the second rubber compound.

[0123] After the second rubber compound is thoroughly mixed using a kneader, it is extruded using a rubber extruder to form a conductive sealing material for the cable core.

[0124] The embodiments of the present invention also provide several comparative examples for comparison with the conductive sealing materials of cable cores of the embodiments of the present invention. Specifically, the raw material composition of the comparative examples is shown in Table 2 below.

[0125] Comparative Example 1

[0126] The only difference between Comparative Example 1 and Example 1 is that the amount of carbon black added is 60 parts, specifically 40 parts of acetylene black and 20 parts of conductive carbon black.

[0127] Comparative Example 2

[0128] The only difference between Comparative Example 2 and Example 1 is that the amount of tackifier added is 30 parts, specifically 15 parts of coumarone resin and 15 parts of rosin resin.

[0129] Comparative Example 3

[0130] The only difference between Comparative Example 3 and Example 1 is that the plasticizer added is 70 parts, specifically 30 parts of white naphthenic oil, 20 parts of transformer oil and 20 parts of paraffin oil.

[0131] Comparative Example 4

[0132] The only difference between Comparative Example 4 and Example 1 is that no thickener is added.

[0133] Comparative Example 5

[0134] The only difference between Comparative Example 5 and Example 1 is that no plasticizer is added.

[0135] Table 2 Raw material composition of Comparative Examples 1-5

[0136]

[0137]

[0138] Furthermore, the volume resistivity, peel strength to steel plate, and peel strength to polyethylene plate of Examples 1-6 and Comparative Examples 1-5 were tested, and the specific test results are shown in Table 3 below.

[0139] Table 3 Test data of Examples 1-6 and Comparative Examples 1-5

[0140]

[0141]

[0142] Based on the test data shown in Table 3, it can be seen that the volume resistivity of Examples 1-6 is significantly lower than that of Comparative Examples 1-5. Among them, compared with Example 1, the amount of carbon black added in Comparative Example 1 is only 60 parts, and the volume resistivity of the resulting sealing material is significantly increased, indicating that the more carbon black used within a certain range, the stronger the conductivity of the conductive sealing material for the cable core.

[0143] Furthermore, based on the test data shown in Table 3, it can be seen that the peel strength of Examples 1-6 on steel plates and polyethylene plates is significantly better than that of Comparative Examples 1-5. Compared to Example 1, Comparative Example 2 added 30 parts of tackifier, and Comparative Example 3 added 70 parts of plasticizer, both of which are outside the composition range of this application. The resulting sealing materials have lower peel strength on steel plates and polyethylene plates and poor adhesion performance. Compared to Example 1, Comparative Example 4 did not add tackifier, and Comparative Example 5 did not add plasticizer. The resulting sealing materials have extremely low peel strength on steel plates and polyethylene plates and extremely poor adhesion performance. This further illustrates that the tackifier and plasticizer in the composition of this application have a synergistic effect, and their simultaneous addition makes the adhesion performance of the conductive sealing material for cable cores stronger.

[0144] In addition, the present invention also provides a cable accessory, wherein the outer surface of the conductor connection of the cable accessory is covered with the conductive sealing material of the cable core as described above.

[0145] The preparation of the conductive sealing material for the cable core follows the method described above. By coating the cable core with this conductive sealing material, a good sealing effect is achieved, and its conductivity improves electric field distortion, especially providing good shielding for irregular conductors, thus ensuring the normal and stable operation of the cable accessories.

[0146] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0147] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0148] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for preparing a conductive sealing material for cable cores, characterized in that, The conductive sealing material for the cable core comprises the following raw materials in parts by weight: The composition includes 100 parts of base rubber, 1-3 parts of heat resistant agent, 1-2 parts of antioxidant, 80-120 parts of plasticizer, 50-80 parts of tackifier, and 80-120 parts of carbon black, wherein the base rubber is one or more of ethylene propylene rubber, butyl rubber, and silicone rubber, and the heat resistant agent is zinc oxide. The method for preparing the conductive sealing material for the cable core includes the following steps: 100 parts of the base rubber, 1-3 parts of heat resistant agent and 1-2 parts of antioxidant were kneaded at room temperature using a kneader to obtain the first rubber compound, wherein the kneading time was 15-25 minutes; Add 50-80 parts of tackifier, 80-120 parts of plasticizer and 80-120 parts of carbon black to the first rubber compound, and knead and mix it at 95-105°C using a kneader to obtain the second rubber compound, wherein the kneading time is 15-35 minutes. After the second rubber compound is thoroughly mixed using a kneader, the mixed second rubber compound is extruded and molded using a rubber extruder to obtain the conductive sealing material for the cable core. The 50-80 parts of tackifier include a first part of tackifier, a second part of tackifier and a third part of tackifier; the 80-120 parts of carbon black include a fourth part of carbon black, a fifth part of carbon black and a sixth part of carbon black; and the 80-120 parts of plasticizer include a seventh part of plasticizer and an eighth part of plasticizer. The step of adding 50-80 parts of tackifier, 80-120 parts of plasticizer, and 80-120 parts of carbon black to the first rubber compound, and kneading and mixing it in a kneader to obtain the second rubber compound includes: The first part of tackifier and the fourth part of carbon black are added to the first rubber compound, and the first intermediate material is obtained by kneading and mixing in a kneader. The temperature at which the first intermediate material is obtained by kneading is 95-105°C, and the time for kneading the first intermediate material is 15-25 minutes. The second part of the thickener, the fifth part of the carbon black and the seventh part of the plasticizer are added to the first intermediate material, and the mixture is kneaded and mixed in an intensive kneading machine to obtain the second intermediate material. The temperature at which the second intermediate material is kneaded is 95-105°C and the time for kneading is 15-25 minutes. The third part of the tackifier, the sixth part of the carbon black, and the eighth part of the plasticizer are added to the second intermediate material, and the mixture is kneaded and mixed using a kneader to obtain the second rubber compound. The temperature at which the second rubber compound is kneaded is 95-105°C, and the kneading time is 25-35 minutes.

2. The method for preparing the conductive sealing material for cable cores as described in claim 1, characterized in that, The antioxidant is one or both of 2,2,4-trimethyl-1,2-dihydroquinoline polymer and 2-thiol-benzimidazole.

3. The method for preparing the conductive sealing material for cable cores as described in claim 2, characterized in that, The plasticizer is one or more of leucyclohexane oil, transformer oil, paraffin oil, polyisobutylene, dioctyl sebacate, and liquid polybutadiene; the tackifier is one or more of phenolic resin, rosin resin, coumarone resin, and terpene resin.

4. The method for preparing the conductive sealing material for cable cores as described in claim 1, characterized in that, The carbon black is one or more of acetylene black, conductive carbon black, and channel black.

5. A cable accessory, characterized in that, The outer surface of the conductor connection of the cable accessory is covered with the cable core conductive sealing material prepared by the method for preparing the cable core conductive sealing material as described in any one of claims 1 to 4.

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