A conductive ethylene propylene diene monomer rubber and its preparation method and application

Abstract

The present invention discloses a conductive ethylene propylene diene monomer rubber and its preparation method and application. The preparation raw materials of the above-mentioned conductive ethylene propylene diene monomer rubber include specific tear resistance aids and a certain amount of flame retardant fillers, conductive carbon black and vulcanizing agents, achieving the simultaneous improvement of tensile strength, toughness, tear resistance, conductivity and flame retardancy, and can better meet the use requirements of cable accessories including separable connectors. The present invention also provides the preparation method and application of the above-mentioned conductive ethylene propylene diene monomer rubber.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive rubber, and particularly relates to a conductive ethylene propylene diene monomer rubber and its preparation method and application. Background Art

[0002] For cable accessories such as separable connectors, the scenarios where they are used have the potential for fire sources or sudden fires, and thus they need to have a certain flame retardancy. At the same time, in order to ensure the conductive shielding effect, conductive rubber, such as conductive ethylene propylene diene monomer rubber, needs to be used.

[0003] Existing conductive ethylene propylene diene monomer rubbers still have the following problems: 1) The tear strength is not high. For cable accessories such as separable connectors, the conductive rubber may be subjected to various mechanical forces during the connection and separation processes, such as stretching, bending, and twisting. The insufficient tear resistance of the existing conductive ethylene propylene diene monomer rubber leads to easy tearing or breakage when subjected to these mechanical forces, thereby resulting in a decrease or even failure of the conductive performance; 2) It is difficult to balance strength and flame retardancy performance because the addition of a large amount of flame retardant fillers will cause a significant reduction in mechanical properties.

[0004] With the gradual increase in the cable voltage level, developing a conductive ethylene propylene diene monomer rubber with high tear strength and high flame retardancy is an urgent problem to be solved at present. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a conductive ethylene propylene diene monomer rubber, which has characteristics such as high tear strength, high tensile strength, high toughness, high flame retardancy, and high conductivity.

[0006] The present invention also provides a preparation method of the conductive ethylene propylene diene monomer rubber.

[0007] The present invention also provides the application of the above-mentioned conductive ethylene propylene diene monomer rubber.

[0008] The first aspect embodiment of the present invention relates to a conductive ethylene propylene diene monomer rubber, which comprises the following preparation raw materials by weight parts: 100 parts of ethylene propylene diene monomer rubber, ≥25 parts of conductive carbon black, 50 - 100 parts of flame retardant filler, 3 - 5 parts of vulcanizing agent, 2 - 5 parts of tear resistance aid; the tear resistance aid has the brand number RK801L.

[0009] The conductive ethylene propylene diene monomer rubber according to the first aspect embodiment of the present invention has at least the following beneficial effects:

[0010] The anti - tearing aid RK801L includes nitrogen - containing heterocyclic compounds and fatty acid derivatives, which can form physical binding effects such as hydrogen bonds with the surface of fillers, improve the filler dispersion. At the same time, the nitrogen - containing heterocyclic compounds may affect the vulcanization process, facilitating the formation of a moderate network structure in the system, taking into account both strength and toughness. In addition, the fatty acid derivatives play a plasticizing role and promote filler dispersion. Furthermore, the anti - tearing aid may form a more uniform cross - linked network structure by improving the filler dispersion, the interfacial bonding force between the filler and the rubber, and regulating the cross - linking degree, which is more conducive to exerting the functions of conductive carbon black (conductive, reinforcing, etc.) and flame - retardant fillers (flame - retardant, reinforcing, etc.), achieving the simultaneous improvement of tensile strength, toughness, tear strength, conductivity, and flame retardancy, effectively solving the problems such as low tear strength of existing conductive ethylene - propylene - diene monomer rubber and strength reduction caused by the addition of flame - retardant fillers.

[0011] It should be noted that for existing conductive ethylene - propylene - diene monomer rubber, although it is possible to achieve high tensile strength (without adding flame - retardant fillers or reducing the amount of flame - retardant fillers added), it is still difficult to improve the tear strength. This is because tear resistance is the ability of a material to resist damage when subjected to a tearing force, and tensile strength refers to the maximum force that a material can withstand when subjected to a tensile force. The two are somewhat related, but not necessarily strictly positively correlated. That is to say, a material with high tensile strength does not necessarily have good tear resistance. Furthermore, it can be understood that improving tear strength is of higher technical difficulty compared to improving tensile strength.

[0012] The above - mentioned conductive ethylene - propylene - diene monomer rubber has very good electrical conductivity, can better protect insulating materials, reduce the electric field gradient and voltage gradient, thereby making the cable transmit electrical energy more stably and extending the service life.

[0013] According to some embodiments of the present invention, the Mooney viscosity ML(1 + 4,125°C) of the ethylene - propylene - diene monomer rubber is ≥55, the ethylene content is ≥55%, and the ENB content is ≤4.5%. The ethylene content and ENB content are both mass contents.

[0014] The Mooney viscosity of the raw rubber of ethylene - propylene - diene monomer rubber is relatively high, with high filling capacity, and can provide appropriate shear force, improving the mixing uniformity and mechanical properties. A high vinyl content is beneficial to improving mechanical properties. In addition, the higher the ENB content, the more it may affect heat resistance. Furthermore, by controlling the ENB content, ethylene content, and viscosity of the ethylene - propylene - diene monomer rubber, the rubber material can have better heat resistance, compression set, and tensile strength, thereby obtaining high - performance ethylene - propylene - diene monomer rubber.

[0015] According to some embodiments of the present invention, the ENB content of the ethylene - propylene - diene monomer rubber is ≤4.5%, and specifically can be 3.8% - 4.5%.

[0016] According to some embodiments of the present invention, the Mooney viscosity ML(1+4,125°C) of the ethylene-propylene-diene monomer rubber is 55-60.

[0017] According to some embodiments of the present invention, the ethylene content of the ethylene-propylene-diene monomer rubber is 55%-58%. The above ethylene content range can better ensure low-temperature resistance, compressibility and processability.

[0018] According to some embodiments of the present invention, the tensile strength of the ethylene-propylene-diene monomer rubber is ≥20 MPa, the elongation at break is ≥300%, and the modulus at 300% elongation is ≥16 MPa.

[0019] According to some embodiments of the present invention, the anti-tearing aid is 3-4.5 parts.

[0020] According to some embodiments of the present invention, the conductive carbon black is super conductive carbon black.

[0021] Super conductive carbon black is conductive carbon black with a resistivity ≤1 Ω·m, and its conductivity is better than that of ordinary conductive carbon black. For example, the super conductive carbon black Z90C produced by Tianjin Huayuan Chemical Technology Co., Ltd. is selected as the super conductive carbon black.

[0022] According to some embodiments of the present invention, the conductive carbon black is 25-35 parts. The higher the amount of conductive carbon black used, the better the conductivity, but it will increase the cost and will affect the toughness to a certain extent.

[0023] According to some embodiments of the present invention, the flame retardant filler includes antimony trioxide, decabromodiphenylethane and zinc borate, and also includes one or more combinations of aluminum hydroxide, magnesium hydroxide, talc powder, calcium carbonate. The above flame retardant system has a synergistic effect and can improve the flame retardancy. It can be understood that this flame retardant system combination can obtain higher flame retardancy under the same amount of flame retardant added, or can reduce the addition amount of flame retardant filler under the same flame retardant performance.

[0024] According to some embodiments of the present invention, the flame retardant filler includes antimony trioxide, decabromodiphenylethane, zinc borate and magnesium hydroxide.

[0025] According to some embodiments of the present invention, the weight ratio of antimony trioxide, decabromodiphenylethane, zinc borate is 4:5:(1-4), and zinc borate ≥5 parts.

[0026] According to some embodiments of the present invention, the flame retardant filler is 55-95 parts, specifically it can be 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 95 parts or any value between them. Within this range of the amount of flame retardant filler used, the material strength can be better balanced.

[0027] According to some embodiments of the present invention, the raw materials for preparing the conductive ethylene propylene diene monomer rubber further include additives.

[0028] According to some embodiments of the present invention, the additives are selected from one or a combination of more of a plasticizer, an antioxidant, an activator, a dispersant, and a vulcanization accelerator.

[0029] According to some embodiments of the present invention, the amount of the additives is 17 - 45 parts.

[0030] The additives include a plasticizer, and the plasticizer is selected from one or a combination of more of paraffin oil, naphthenic oil, and white oil.

[0031] According to some embodiments of the present invention, the amount of the plasticizer is 12 - 30 parts, specifically, it can be 12 parts, 15 parts, 20 parts, 25 parts, 30 parts, or any value between them.

[0032] According to some embodiments of the present invention, the amount of the plasticizer is 15 - 25 parts.

[0033] According to some embodiments of the present invention, the additives include an antioxidant, and the antioxidant is selected from one or a combination of more of antioxidant RD, antioxidant MB, antioxidant TMQ, and antioxidant MBZ, for example, it can be selected from antioxidant MBZ.

[0034] According to some embodiments of the present invention, the amount of the antioxidant is 1 - 2 parts, specifically, it can be 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, or any value between them.

[0035] According to some embodiments of the present invention, the additives include an activator, and the activator is selected from one or a combination of more of zinc oxide, stearic acid, and zinc stearate.

[0036] According to some embodiments of the present invention, the activator includes zinc oxide with a purity ≥ 95.5 wt%.

[0037] According to some embodiments of the present invention, the amount of the activator is 2 - 6 parts, specifically, it can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, or any value between them.

[0038] According to some embodiments of the present invention, the additives include a dispersant, and the dispersant includes one or two of fatty acids or their derivatives.

[0039] There is a certain difference in compatibility between fatty acids or their derivatives and non - polar ethylene propylene diene monomer rubber, showing good external lubrication effect, which can improve fluidity and filler dispersibility, and is beneficial to improving the compression set resistance of vulcanizates.

[0040] According to some embodiments of the present invention, the dispersant is selected from one or two of a mixture of isoparaffin wax and fatty acid, and fatty acid derivatives.

[0041] The fatty acid derivatives can be, for example, a combination of one or more of fatty acid amides, fatty acid esters, or fatty acid salts. Compared with fatty acids, the fatty acid derivatives have a smaller polarity difference from ethylene propylene diene monomer (EPDM) rubber, which is more conducive to improving the overall performance of the rubber. Similarly, using a mixture of isoparaffin wax and fatty acid can reduce the compatibility difference between fatty acid and EPDM rubber.

[0042] According to some embodiments of the present invention, the dispersant is 1 - 3 parts, specifically it can be 1 part, 2 parts, 3 parts, or any value between them.

[0043] According to some embodiments of the present invention, the additives include vulcanization accelerators, and the vulcanization accelerators are selected from one or a combination of more of dimethyldiphenylthiuram disulfide, N,N - ethylene thiourea, N - tert - butyl - 2 - benzothiazole sulfenamide, zinc dialkyl thiophosphate, and triallyl isocyanurate.

[0044] According to some embodiments of the present invention, the vulcanization accelerators are selected from one or two of zinc dialkyl thiophosphate and triallyl isocyanurate.

[0045] According to some embodiments of the present invention, the vulcanization accelerator is 1 - 4 parts, specifically it can be 1 part, 2 parts, 3 parts, 4 parts, or any value between them.

[0046] According to some embodiments of the present invention, the additives include: 12 - 30 parts of plasticizer, 1 - 2 parts of antioxidant, 2 - 6 parts of activator, 1 - 3 parts of dispersant, and 1 - 4 parts of vulcanization accelerator.

[0047] According to some embodiments of the present invention, the vulcanizing agent is selected from one or a combination of more of dicumyl peroxide, bis - tert - butylperoxide dicumyl, and sulfur.

[0048] According to some embodiments of the present invention, the vulcanizing agent is selected from one or two of dicumyl peroxide and bis - tert - butylperoxide dicumyl.

[0049] According to some embodiments of the present invention, the vulcanizing agent is 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, or any value between them.

[0050] The second - aspect embodiments of the present invention relate to a preparation method of conductive ethylene propylene diene monomer (EPDM) rubber, including:

[0051] The raw materials for preparation including the ethylene propylene diene monomer rubber, conductive carbon black, flame retardant filler, and tear resistance aid are subjected to a first kneading under heating conditions, then cooled, and the raw materials for preparation including the vulcanizing agent are added for a second kneading.

[0052] The above preparation method is used to prepare the above conductive ethylene propylene diene monomer rubber, so it at least has all the beneficial effects possessed by the embodiments of the above conductive ethylene propylene diene monomer rubber. The preparation process of this method is simple and easy to produce and apply.

[0053] Kneading is usually carried out using a Banbury mixer. A Banbury mixer is a plasticating system composed of two relatively rotating rotors, a kneading chamber, and an upper plug. The temperature can be adjusted. Inside the plasticating system, the material is subjected to the pressure of the upper plug and the frictional force of the two relatively rotating rotors, and undergoes repeated shearing, tearing, stirring, and friction to increase the plasticity of the material and make it disperse evenly.

[0054] According to some embodiments of the present invention, the temperature of the heating is 130 - 150 °C.

[0055] According to some embodiments of the present invention, the steps of the first kneading include: under the condition of 130 - 150 °C, plasticating the ethylene propylene diene monomer rubber, adding the raw materials for preparation including the tear resistance aid for a third kneading, and adding the raw materials for preparation including the conductive carbon black and the flame retardant filler for a fourth kneading.

[0056] According to some embodiments of the present invention, when the raw materials for preparation of the conductive ethylene propylene diene monomer rubber further include the activator and / or the antioxidant and / or the dispersant, the third kneading is: adding the tear resistance aid, and the raw materials for preparation including the activator and / or the antioxidant and / or the dispersant for a third kneading.

[0057] According to some embodiments of the present invention, the time of the third kneading is 1 - 5 min.

[0058] According to some embodiments of the present invention, when the raw materials for preparation of the conductive ethylene propylene diene monomer rubber further include the plasticizer, the fourth kneading is: adding the raw materials for preparation including the conductive carbon black, the flame retardant filler, and the plasticizer for a fourth kneading.

[0059] According to some embodiments of the present invention, the fourth kneading is one-step kneading or stepwise kneading. Among them, stepwise kneading means adding the corresponding raw materials in segments for stepwise kneading. Adding in segments can be divided into two or more segments, and the amount added in each segment can be the same or different, and the raw material composition added in each segment can be the same or different.

[0060] According to some embodiments of the present invention, the time of the fourth mixing is 5-10 min. It can be understood that when the fourth mixing is stepwise mixing, this time refers to the total time of all mixing steps.

[0061] According to some embodiments of the present invention, when the raw materials for preparing the conductive ethylene propylene diene monomer rubber further include the vulcanization accelerator, the second mixing is: adding the raw materials including the vulcanizing agent and the vulcanization accelerator for the second mixing.

[0062] According to some embodiments of the present invention, the temperature of the second mixing is 50-70 °C. It can be understood that the cooling is to cool down to the temperature of the second mixing.

[0063] According to some embodiments of the present invention, the time of the second mixing is 2-5 min.

[0064] According to some embodiments of the present invention, before the second mixing after cooling, it further includes: pre-mixing the rubber compound obtained from the first mixing.

[0065] According to some embodiments of the present invention, the time of the pre-mixing is 1-2 min.

[0066] According to some embodiments of the present invention, the time of the plasticating is 1-2 min.

[0067] The third aspect embodiment of the present invention relates to the application of the above-mentioned conductive ethylene propylene diene monomer rubber in the preparation of cable accessories.

[0068] In view of the above advantages of the conductive ethylene propylene diene monomer rubber, the performance and service life of the cable accessories using the conductive ethylene propylene diene monomer rubber can be improved.

[0069] According to some embodiments of the present invention, the cable accessories include separable connectors.

[0070] In this article, "a plurality of" means more than two, including two; when referring to a numerical range, it includes the end values and any subset range between the end values.

[0071] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. Detailed Description of Specific Embodiments

[0072] The following details the embodiments of the present invention. The embodiments are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0073] In the following embodiments, the relevant raw materials are described as follows:

[0074] Ethylene Propylene Diene Monomer (EPDM): Shaanxi Yanchang Petroleum (Group) Yan'an Energy & Chemical Industry Co., Ltd., EPDM-Y-05H4D4 EPDM, with Mooney viscosity ML(1+4,125℃) of 59.4, ethylene content of 57.82%, ENB content of 4.07%, tensile strength of 21.5 MPa, elongation at break of 362%, and modulus at 300% elongation of 16.8 MPa; ARLANXEO 2650C EPDM, with ML(1+4,125℃) of 25.0, ethylene content of 46%, and ENB content of 6.0%; Jilin Petrochemical Company, PetroChina Company Limited, J-4045 EPDM, with Mooney viscosity ML(1+4,100℃) of 45.0, ethylene content of 52.9%, ENB content of 7.6%, tensile strength of 18.2 MPa, elongation at break of 376%, and modulus at 300% elongation of 13.8 MPa.

[0075] Conductive carbon black: Tianjin Huayuan Chemical Technology Co., Ltd., Superconductive carbon black Z90C, nitrogen absorption value > 480 m 2 / g, iodine absorption value ≥ 460 mg / g, DBP absorption value of 260 - 280 cc / 100 g, and resistivity ≤ 1 Ω·m.

[0076] Tear resistance aid: Purchased from Jiangsu Ruiba New Materials Technology Co., Ltd., including: RK801L, a mixture of nitrogen heterocyclic compounds, fatty acid derivatives, and carriers; RT101, rosin and aliphatic resin modifiers; RT101A, a mixture of modified rosin and aromatic resins; RT102, a mixture of modified alicyclic resins.

[0077] Dispersant: Jiangsu Ruiba New Materials Technology Co., Ltd., RL-20, a mixture of fatty acid esters and fatty acid salts.

[0078] Internal mixer: Produced by Guangdong Lina Industry Co., Ltd., LN-LT-1L internal mixer.

[0079] For the remaining raw materials or equipment involved, if not otherwise specified, they are all conventional raw materials or equipment that can be purchased commercially.

[0080] Example 1

[0081] In this embodiment, a conductive ethylene propylene diene monomer rubber was prepared, and the following raw materials were included: 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4), 30 kg of super conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 5 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RK801L), 3 kg of rubber processing dispersant (RL-20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC, triallyl isocyanurate).

[0082] The preparation steps are as follows:

[0083] (1) Heat the internal mixer to 130 - 150 °C, and put 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4) for plasticizing for 1 min;

[0084] (2) Add 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RK801L), 1 kg of antioxidant MBZ, and 3 kg of rubber processing dispersant (RL-20), and mix for 2 min. After mixing evenly, proceed with the following steps;

[0085] (3) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 2.5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 2.5 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0086] (4) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 2.5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 2.5 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0087] (5) After mixing evenly, take out the mixed rubber block from the internal mixer;

[0088] (6) Cool the internal mixer to 50 - 70 °C, and put the mixed rubber prepared in step B into the internal mixer and mix for 1 min;

[0089] (7) Add 3 kg of vulcanizing agent DCP and 1.5 kg of rubber vulcanization accelerator (TAIC) and mix for 3 min;

[0090] (8) After mixing evenly, take out the mixed rubber block from the internal mixer, and then the conductive ethylene propylene diene monomer rubber is obtained.

[0091] Example 2

[0092] In this embodiment, a conductive ethylene propylene diene monomer (EPDM) rubber was prepared, and the following raw materials were used: 100 kg of ethylene propylene diene monomer (EPDM - Y - 05H4D4), 30 kg of super conductive carbon black (Z90C), 10 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 10 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti - tear agent (RK801L), 3 kg of rubber processing dispersant (RL - 20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0093] The preparation steps are as follows:

[0094] (1) Heat the internal mixer to 130 - 150 °C, and put 100 kg of ethylene propylene diene monomer (EPDM - Y - 05H4D4) into it for plasticizing for 1 min;

[0095] (2) Add 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti - tear agent (RK801L), 1 kg of antioxidant MBZ, and 3 kg of rubber processing dispersant (RL - 20), and mix for 2 min. After mixing evenly, proceed with the following steps;

[0096] (3) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 5 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0097] (4) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 5 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0098] (5) After mixing evenly, take out the mixed rubber block from the internal mixer;

[0099] (6) Cool the internal mixer to 50 - 70 °C, and put the mixed rubber prepared in step B into the internal mixer for mixing for 1 min;

[0100] (7) Add 3 kg of vulcanizing agent DCP and 1.5 kg of rubber vulcanization accelerator (TAIC), and mix for 3 min;

[0101] (8) After mixing evenly, take out the mixed rubber block from the internal mixer, and thus obtain the conductive ethylene propylene diene monomer (EPDM) rubber.

[0102] Example 3

[0103] In this embodiment, a conductive ethylene propylene diene monomer (EPDM) rubber was prepared, and the preparation raw materials included: 100 kg of ethylene propylene diene monomer (EPDM - Y - 05H4D4), 30 kg of super conductive carbon black (Z90C), 15 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 15 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of tear resistance aid (RK801L), 3 kg of rubber processing dispersant (RL - 20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0104] The preparation steps are as follows:

[0105] (1) Heat the internal mixer to 130 - 150 °C, and put 100 kg of ethylene propylene diene monomer (EPDM - Y - 05H4D4) into it for plasticizing for 1 min;

[0106] (2) Add 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of tear resistance aid (RK801L), 1 kg of antioxidant MBZ, and 3 kg of rubber processing dispersant (RL - 20), and mix for 2 min. After mixing evenly, proceed with the following steps;

[0107] (3) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 7.5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 7.5 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0108] (4) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 7.5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 7.5 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0109] (5) After mixing evenly, take out the mixed rubber block from the internal mixer;

[0110] (6) Cool the internal mixer to 50 - 70 °C, and put the mixed rubber prepared in step B into the internal mixer and mix for 1 min;

[0111] (7) Add 3 kg of vulcanizing agent DCP and 1.5 kg of rubber vulcanization accelerator (TAIC), and mix for 3 min;

[0112] (8) After mixing evenly, take out the mixed rubber block from the internal mixer, and thus obtain the conductive ethylene propylene diene monomer (EPDM) rubber.

[0113] Example 4

[0114] In this embodiment, a conductive ethylene propylene diene monomer (EPDM) rubber was prepared, and the following raw materials were included: 100 kg of ethylene propylene diene monomer (EPDM - Y - 05H4D4), 30 kg of super conductive carbon black (Z90C), 20 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 20 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti - tearing agent (RK801L), 3 kg of rubber processing dispersant (RL - 20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0115] The preparation steps are as follows:

[0116] (1) Heat the internal mixer to 130 - 150 °C, and put 100 kg of ethylene propylene diene monomer (EPDM - Y - 05H4D4) into it for plasticizing for 1 min;

[0117] (2) Add 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti - tearing agent (RK801L), 1 kg of antioxidant MBZ, and 3 kg of rubber processing dispersant (RL - 20), and mix for 2 min. After mixing evenly, proceed with the following steps;

[0118] (3) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 10 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 10 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0119] (4) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 10 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 10 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0120] (5) After mixing evenly, take out the mixed rubber block from the internal mixer;

[0121] (6) Cool the internal mixer to 50 - 70 °C, and put the mixed rubber prepared in step B into the internal mixer for mixing for 1 min;

[0122] (7) Add 3 kg of vulcanizing agent DCP and 1.5 kg of rubber vulcanization accelerator (TAIC), and mix for 3 min;

[0123] (8) After mixing evenly, take out the mixed rubber block from the internal mixer, and thus obtain the conductive ethylene propylene diene monomer (EPDM) rubber.

[0124] Example 5

[0125] In this embodiment, a conductive ethylene propylene diene monomer rubber was prepared, and the following raw materials were included: 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4), 30 kg of super conductive carbon black (Z90C), 30 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 20 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear additive (RK801L), 3 kg of rubber processing dispersant (RL-20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0126] The preparation steps are as follows:

[0127] (1) Heat the internal mixer to 130 - 150 °C, and put 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4) into it for plasticizing for 1 min;

[0128] (2) Add 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear additive (RK801L), 1 kg of antioxidant MBZ, and 3 kg of rubber processing dispersant (RL-20), and mix for 2 min. After mixing evenly, proceed with the following steps;

[0129] (3) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 15 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 10 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0130] (4) Add 10 kg of paraffin oil, 15 kg of super conductive carbon black (Z90C), 15 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 10 kg of zinc borate, and mix for 3 min. After mixing evenly, proceed with the following steps;

[0131] (5) After mixing evenly, take out the mixed rubber block from the internal mixer;

[0132] (6) Cool the internal mixer to 50 - 70 °C, and put the mixed rubber prepared in step B into the internal mixer for mixing for 1 min;

[0133] (7) Add 3 kg of vulcanizing agent DCP and 1.5 kg of rubber vulcanization accelerator (TAIC), and mix for 3 min;

[0134] (8) After mixing evenly, take out the mixed rubber block from the internal mixer, and then the conductive ethylene propylene diene monomer rubber is obtained.

[0135] Example 6

[0136] In this example, a conductive ethylene propylene diene monomer (EPDM) rubber was prepared, which included the following raw materials for preparation: 100 kg of ethylene propylene diene monomer (2650C), 30 kg of super conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 5 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RK801L), 3 kg of rubber processing dispersant (RL-20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0137] The preparation steps refer to Example 1.

[0138] Example 7

[0139] In this example, a conductive ethylene propylene diene monomer (EPDM) rubber was prepared, which included the following raw materials for preparation: 100 kg of ethylene propylene diene monomer (J-4045), 30 kg of super conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 5 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RK801L), 3 kg of rubber processing dispersant (RL-20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0140] The preparation steps refer to Example 1.

[0141] Example 8

[0142] In this example, a conductive ethylene propylene diene monomer (EPDM) rubber was prepared, which included the following raw materials for preparation: 100 kg of ethylene propylene diene monomer (EPDM-Y-05H4D4), 30 kg of super conductive carbon black (Z90C), 25 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 5 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RK801L), 3 kg of rubber processing dispersant (RL-20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0143] The preparation steps refer to Example 1.

[0144] Example 9

[0145] In this embodiment, a conductive ethylene propylene diene monomer rubber was prepared, and the following raw materials were included: 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4), 30 kg of super conductive carbon black (Z90C), 30 kg of magnesium hydroxide, 20 kg of antimony trioxide, 5 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RK801L), 3 kg of rubber processing dispersant (RL-20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0146] The preparation steps refer to Example 1.

[0147] Example 10

[0148] In this embodiment, a conductive ethylene propylene diene monomer rubber was prepared, and the following raw materials were included: 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4), 50 kg of super conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 25 kg of decabromodiphenyl ethane, 20 kg of antimony trioxide, 5 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RK801L), 3 kg of rubber processing dispersant (RL-20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0149] The preparation steps refer to Example 1.

[0150] Comparative Example 1

[0151] In this comparative example, a conductive ethylene propylene diene monomer rubber was prepared, and the following raw materials were included: 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4), 30 kg of super conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 25 kg of decabromodiphenyl ethane, 20 kg of antimony trioxide, 5 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 3 kg of rubber processing dispersant (RL-20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0152] The preparation steps are as follows:

[0153] (1) Heat the internal mixer to 130 - 150 °C, and put 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4) for plasticizing for 1 min;

[0154] (2) Add 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 1 kg of antioxidant MBZ, and 3 kg of rubber processing dispersant (RL-20), mix for 2 min, and after mixing evenly, proceed with the following steps;

[0155] (3) Add 10 kg of paraffin oil, 15 kg of super-conductive carbon black (Z90C), 2.5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 2.5 kg of zinc borate, and knead for 3 min. After kneading evenly, perform the following steps;

[0156] (4) Add 10 kg of paraffin oil, 15 kg of super-conductive carbon black (Z90C), 2.5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 2.5 kg of zinc borate, and knead for 3 min. After kneading evenly, perform the following steps;

[0157] (5) After kneading evenly, take out the kneaded rubber block from the internal mixer;

[0158] (6) Cool the internal mixer to 50 - 70 °C, and put the kneaded rubber compound prepared in step B into the internal mixer and knead for 1 min;

[0159] (7) Add 3 kg of vulcanizing agent DCP and 1.5 kg of rubber vulcanization accelerator (TAIC) and knead for 3 min;

[0160] (8) After kneading evenly, take out the kneaded rubber block from the internal mixer, and then conductive ethylene propylene diene monomer rubber is obtained.

[0161] Comparative Example 2

[0162] This comparative example prepared a kind of conductive ethylene propylene diene monomer rubber, including the following preparation raw materials: 100 kg of ethylene propylene diene monomer rubber (EPDM - Y - 05H4D4), 30 kg of super-conductive carbon black (Z90C), 10 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 10 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with purity above 95.5 wt%), 3 kg of rubber processing dispersant (RL - 20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0163] The preparation steps are as follows:

[0164] (1) Heat the internal mixer to 130 - 150 °C, and put 100 kg of ethylene propylene diene monomer rubber (EPDM - Y - 05H4D4) for plasticizing for 1 min;

[0165] (2) Add 3 kg of zinc oxide (with purity above 95.5 wt%), 1 kg of antioxidant MBZ, and 3 kg of rubber processing dispersant (RL - 20), and knead for 2 min. After kneading evenly, perform the following steps;

[0166] (3) Add 10 kg of paraffin oil, 15 kg of super-conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 5 kg of zinc borate, and knead for 3 min. After kneading evenly, perform the following steps;

[0167] (4) Add 10 kg of paraffin oil, 15 kg of super-conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 5 kg of zinc borate, and knead for 3 min. After kneading evenly, perform the following steps;

[0168] (5) After kneading evenly, take out the kneaded rubber block from the internal mixer;

[0169] (6) Cool the internal mixer to 50 - 70 °C, and put the kneaded rubber compound prepared in step B into the internal mixer and knead for 1 min;

[0170] (7) Add 3 kg of curing agent DCP and 1.5 kg of rubber vulcanization accelerator (TAIC) and knead for 3 min;

[0171] (8) After kneading evenly, take out the kneaded rubber block from the internal mixer, and thus obtain conductive ethylene propylene diene monomer rubber.

[0172] Comparative Example 3

[0173] This comparative example prepared a conductive ethylene propylene diene monomer rubber, including the following preparation raw materials: 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4), 30 kg of super-conductive carbon black (Z90C), 40 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 20 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RK801L), 3 kg of rubber processing dispersant (RL-20), 3 kg of curing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0174] The preparation steps are as follows:

[0175] (1) Heat the internal mixer to 130 - 150 °C, and put 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4) for plasticizing for 1 min;

[0176] (2) Add 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RK801L), 1 kg of antioxidant MBZ, and 3 kg of rubber processing dispersant (RL-20), and knead for 2 min. After kneading evenly, perform the following steps;

[0177] (3) Add 10 kg of paraffin oil, 15 kg of super-conductive carbon black (Z90C), 20 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 10 kg of zinc borate, and knead for 3 min. After kneading evenly, perform the following steps;

[0178] (4) Add 10 kg of paraffin oil, 15 kg of super-conductive carbon black (Z90C), 20 kg of magnesium hydroxide, 12.5 kg of decabromodiphenylethane, 10 kg of antimony trioxide, and 10 kg of zinc borate, and knead for 3 min. After kneading evenly, perform the following steps;

[0179] (5) After kneading evenly, take out the kneaded rubber block from the internal mixer;

[0180] (6) Cool the internal mixer to 50 - 70 °C, and put the kneaded rubber compound prepared in step B into the internal mixer and knead for 1 min;

[0181] (7) Add 3 kg of curing agent DCP and 1.5 kg of rubber vulcanization accelerator (TAIC) and knead for 3 min;

[0182] (8) After kneading evenly, take out the kneaded rubber block from the internal mixer, and then the conductive ethylene propylene diene monomer rubber is obtained.

[0183] Comparative Example 4

[0184] This comparative example prepared a conductive ethylene propylene diene monomer rubber, including the following preparation raw materials: 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4), 30 kg of super-conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 5 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RT101A), 3 kg of rubber processing dispersant (RL-20), 3 kg of curing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0185] The preparation steps refer to Example 1.

[0186] Comparative Example 5

[0187] This comparative example prepared a conductive ethylene propylene diene monomer rubber, including the following preparation raw materials: 100 kg of ethylene propylene diene monomer rubber (EPDM-Y-05H4D4), 30 kg of super conductive carbon black (Z90C), 5 kg of magnesium hydroxide, 25 kg of decabromodiphenylethane, 20 kg of antimony trioxide, 5 kg of zinc borate, 20 kg of paraffin oil, 1 kg of antioxidant MBZ, 3 kg of zinc oxide (with a purity of more than 95.5 wt%), 4 kg of anti-tear aid (RT102), 3 kg of rubber processing dispersant (RL-20), 3 kg of vulcanizing agent DCP, and 1.5 kg of rubber vulcanization accelerator (TAIC).

[0188] The preparation steps refer to Example 1.

[0189] Test Example

[0190] The flame retardant grade was determined using the UL94 standard; the tear strength was determined using the GB / T 529-2008 standard, the tensile strength was determined using the GB / T528-2009 standard; the elongation at break was determined using the GB / T 528-2009 standard; the volume resistivity was determined using the GB / T 2439-2001 standard; the instrument for testing the volume resistivity was the BD400H semi-conductive rubber and plastic material resistivity tester of Xi'an Honghu Testing Instrument Co., Ltd.

[0191] The test results are shown in Table 1.

[0192] Table 1 Performance comparison of conductive ethylene propylene diene monomer rubbers prepared in Examples 1-10 and Comparative Examples 1-5

[0193]

[0194]

[0195] It can be seen that compared with Example 1, in Comparative Example 1, 4 kg of anti-tear aid (RK801L) was added in Example 1, and the tear strength at 25°C and 150°C both increased significantly; similarly, compared with Example 2, in Comparative Example 2, 4 kg of anti-tear aid (RK801L) was added in Example 2, and the tear strength at 25°C and 150°C both increased significantly.

[0196] Comparing Comparative Examples 4 and 5 with Example 1, it can be seen that in Comparative Example 4, anti-tear resin (RT101A) was used, and in Comparative Example 5, anti-tear resin (RT102) was used. The improvement amplitude of the tear strength was significantly less than that of the anti-tear aid (RK801L) in Example 1. It should be noted that the volume resistivity of Comparative Examples 4 and 5 fluctuated slightly compared with Example 1, which was within the normal fluctuation range of equipment test errors, that is, it can be understood that the volume resistivities of the two were equivalent.

[0197] Comparing Example 6 and Example 7 with Example 1, it can be seen that using the ethylene-propylene-diene monomer rubber of Example 1 results in better overall mechanical properties. In addition, the ethylene-propylene-diene monomer rubber of Example 1 has a higher viscosity, which may be more conducive to the dispersion of fillers, facilitating the reinforcing effect of fillers and the construction of a conductive network, and thus showing a lower resistivity.

[0198] Comparing Example 8 and Example 9 with Example 1, it can be seen that the specific flame-retardant system combination of Example 1 can achieve higher flame-retardant performance with the same amount of flame retardant. From Comparative Example 3, it can be seen that when the flame-retardant filler is 105 parts by weight, the strength decreases, and the tear strength at 25°C and 150°C does not meet the performance index requirements.

[0199] By comparing Examples 1-5 with Comparative Example 3, it can be seen that as the weight fraction of the flame-retardant filler increases, the tear strength decreases, but the performance change range of Examples 1-5 is gentler. In Comparative Example 3, when the flame-retardant filler is 105 parts by weight (greater than 100 parts by weight), the decrease in tear strength is significantly more drastic.

[0200] From Example 10, it can be seen that increasing the conductive carbon black to 50 parts significantly reduces the volume resistivity and improves the conductivity, but increasing the conductive carbon black will lead to unnecessary cost increases.

[0201] In view of the advantages of the conductive ethylene-propylene-diene monomer rubber of this example in terms of tensile strength, toughness, tear strength, conductivity, and flame retardancy, it can better meet the application requirements of cable accessories, such as separable connectors. It can be used as a conductive material for flame-retardant separable connectors of 0-35 kV grade cables, which can better protect the insulating material, reduce the electric field gradient and voltage gradient, thereby making the cable transmit electrical energy more stably and extending the service life.

[0202] The present invention has been described in detail above in conjunction with the embodiments, but the present invention is not limited to the above embodiments. Various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A conductive EPDM rubber, characterized in that: The preparation method comprises the following raw materials in parts by weight: 100 parts of EPDM rubber, Conductive carbon black 25-35 parts, Flame retardant filler 50-100 parts, 3-5 parts of vulcanizing agent, 2-5 parts of tear-resistant additive; The brand of the anti-tear additive is RK801L; The EPDM rubber has a Mooney viscosity ML (1+4, 125°C) ≥ 55, an ethylene content ≥ 55%, and an ENB content ≤ 4.5%; The flame retardant filler includes antimony trioxide, decabromodiphenylethane and zinc borate, and also includes a combination of one or more of aluminum hydroxide, magnesium hydroxide, talc and calcium carbonate; the weight ratio of the antimony trioxide, decabromodiphenylethane and zinc borate is 4:5:(1-4), and the zinc borate is ≥5 parts.

2. The conductive EPDM rubber according to claim 1, characterized in that: The flame retardant filler is 55-95 parts.

3. The conductive EPDM rubber according to claim 1, characterized in that: The conductive carbon black is superconductive carbon black; and / or the vulcanizing agent is selected from a combination of one or more of dicumyl peroxide, di-tert-butyl dicumyl peroxide, and sulfur; and / or the anti-tear additive is 3-4.5 parts.

4. The conductive EPDM rubber according to claim 1, characterized in that: The raw materials for preparing the conductive EPDM rubber also include an auxiliary agent, which is selected from a combination of one or more of a plasticizer, an antioxidant, an activator, a dispersant, and a vulcanization accelerator; and / or the auxiliary agent is 17-45 parts.

5. The conductive EPDM rubber according to claim 4, characterized in that: The plasticizer is selected from a combination of one or more of paraffin oil, cyclohexane oil, and white oil; and / or, the plasticizer is 12-30 parts; and / or, the antioxidant is selected from a combination of one or more of antioxidant RD, antioxidant MB, antioxidant TMQ, and antioxidant MBZ; and / or, the antioxidant is 1-2 parts; and / or, the activator is selected from a combination of one or more of zinc oxide, stearic acid, and zinc stearate; and / or, the activator is 2-6 parts; and / or, the dispersant includes one or two of fatty acids or their derivatives; and / or, the dispersant is 1-3 parts; and / or, the vulcanization accelerator is selected from a combination of one or more of dimethyl diphenyl thiuram disulfide, N,N-ethylene thiourea, N-tert-butyl-2-benzothiazole sulfenamide, dialkyl zinc thiophosphate, and triallyl isocyanurate; and / or, the vulcanization accelerator is 1-4 parts.

6. The conductive EPDM rubber according to claim 1, characterized in that: The raw materials for preparing the conductive EPDM rubber also include additives, which include: 12-30 parts of plasticizer, 1-2 parts of antioxidant, 2-6 parts of activator, 1-3 parts of dispersant, and 1-4 parts of vulcanization accelerator.

7. The method for preparing the conductive EPDM rubber according to any one of claims 1 to 6, characterized in that: include: The raw materials including the EPDM rubber, conductive carbon black, flame retardant filler and tear resistant additive are first mixed under heating conditions, then cooled, and the raw materials including the vulcanizing agent are added for second mixing.

8. Use of the conductive EPDM rubber according to any one of claims 1 to 6 in the preparation of cable accessories.

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