Insulating material and its preparation method and application

Abstract

This application belongs to the technical field of insulating materials, and provides an insulating material, its preparation method, and its application. The raw materials for preparing the insulating material include: ethylene propylene rubber, cis-butadiene rubber, trans-1,4-polyisoprene, talc, dielectric agent, filler, coupling agent, antioxidant, vulcanizing agent, and activator. This application uses ethylene propylene rubber as the base material and introduces cis-butadiene rubber, trans-1,4-polyisoprene, and talc for synergistic effects, effectively improving the mechanical properties, processing properties, and withstand voltage insulation properties of the insulating material.

Description

Technical Field

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

[0002] Ethylene propylene rubber has excellent heat resistance, aging resistance and electrical insulation properties, and is widely used in the preparation of wire and cable insulation products. With the increase in electricity requirements and transmission voltage requirements, the insulation materials of cables are required to have higher mechanical properties and insulation properties. Among them, traditional ethylene propylene rubber insulation glue is difficult to meet the current mechanical properties, insulation properties and dielectric properties requirements in medium and high voltage cables during application. In traditional technology, red lead and other materials are added to reduce the water absorption of the rubber to improve the insulation and dielectric properties of the material, but red lead is a toxic and harmful material, which poses environmental and human hazards. In addition, ethylene propylene rubber also has the problem of poor processing performance. During the extrusion process of the rubber, the insulation core may be deformed or the rubber may be unevenly dispersed, which may easily cause the problem of excessive local discharge and affect the mechanical properties and insulation properties of the material. Therefore, how to provide an insulating material with both mechanical properties, insulation properties and processing properties has become a technical problem that urgently needs to be solved. Summary of the invention

[0003] Based on this, an embodiment of the present application provides an insulating material having mechanical properties, processing properties and insulating properties, and a preparation method and application thereof.

[0004] In a first aspect, the present application provides an insulating material, wherein raw materials for preparing the insulating material include:

[0005] Ethylene propylene rubber, butadiene rubber, trans-1,4-polyisoprene, talc, dielectric agent, filler, coupling agent, antioxidant, vulcanizing agent and activator.

[0006] In some embodiments, the raw materials of the insulating material include, by weight:

[0007] 100 parts of ethylene propylene rubber;

[0008] 10 to 20 parts of butadiene rubber;

[0009] 8 to 12 parts of trans-1,4-polyisoprene;

[0010] 25~40 parts of talcum powder;

[0011] Dielectric agent 5~10 parts;

[0012] 25~40 parts of filler;

[0013] 0.4~0.8 parts of coupling agent;

[0014] 2~4 parts of antioxidant;

[0015] 2 to 8 parts of vulcanizing agent; and

[0016] Activator 9~14 parts.

[0017] In some embodiments, the EPDM rubber includes at least one of EPDM dipolymer and EPDM terpolymer.

[0018] Optionally, the EPDM rubber includes EPDM dipolymer and EPDM terpolymer. Based on 100 parts by total mass of the EPDM rubber, the EPDM rubber includes:

[0019] 40 to 60 parts of EPDM rubber; and

[0020] 40~60 parts of EPDM rubber.

[0021] In some embodiments, the talc includes talc modified with a silane coupling agent.

[0022] In some embodiments, the average particle size of the talc is 3 μm to 5 μm.

[0023] In some embodiments, the weight average molecular weight of the trans-1,4-polyisoprene is 30,000 to 50,000.

[0024] In some embodiments, the dielectric agent includes at least one of polyethylene wax, butadiene rubber, and trans-1,4-polyisoprene.

[0025] In some embodiments, the filler includes at least one of calcined modified kaolin, white carbon, and montmorillonite.

[0026] Optionally, the average particle size of the calcined modified kaolin is 2 μm to 4 μm.

[0027] In some embodiments, the coupling agent includes at least one of γ-aminopropyltriethoxysilane, vinyltri(β-methoxyethoxy)silane, and γ-methacryloxypropyltrimethoxysilane.

[0028] Optionally, the coupling agent includes γ-aminopropyltriethoxysilane and vinyltri(β-methoxyethoxy)silane, and further optionally, the mass ratio of γ-aminopropyltriethoxysilane to vinyltri(β-methoxyethoxy)silane is 1:(1.3~1.7).

[0029] In some embodiments, the antioxidant includes at least one of 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine and 2,2,4-trimethyl-1,2-dihydroquinoline polymer.

[0030] Optionally, the antioxidant includes 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine; further optionally, the mass ratio of the 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine is 1:(0.8~1.2).

[0031] In some embodiments, the vulcanizing agent is a main vulcanizing agent and an auxiliary vulcanizing agent.

[0032] Optionally, the primary vulcanizing agent includes dicumyl peroxide.

[0033] Optionally, the co-vulcanizing agent includes at least one of liquid polybutadiene and N,N-m-phenylene-bismaleimide.

[0034] Optionally, the vulcanizing agent includes liquid polybutadiene and dicumyl peroxide; further optionally, the mass ratio of the liquid polybutadiene to dicumyl peroxide is 1:(0.8~2).

[0035] In some embodiments, the activator includes at least one of zinc oxide, stearic acid, and zinc stearate.

[0036] Optionally, the activator includes zinc oxide and stearic acid; further optionally, the mass ratio of zinc oxide to stearic acid is (2~8):1.

[0037] In a second aspect, the present application provides a method for preparing the insulating material as described in the first aspect, the preparation method comprising:

[0038] The ethylene-propylene rubber, the butadiene rubber, the trans-1,4-polyisoprene, the talc, the dielectric agent, the filler, the coupling agent, the antioxidant, the vulcanizing agent and the activator are mixed to prepare the insulating material.

[0039] In a third aspect, the present application provides a use of the insulating material as described in the first aspect in the preparation of power transmission products.

[0040] In a fourth aspect, the present application provides a cable, comprising the insulating material as described in the first aspect.

[0041] Compared with the traditional technology, this application has at least the following beneficial effects:

[0042] This application is coordinated with ethylene propylene rubber, cis-1,4-polyisoprene and talcum powder. Both cis-1,4-polyisoprene and trans-1,4-polyisoprene are non-polar materials, have good compatibility with ethylene propylene rubber, and trans-1,4-polyisoprene can be used as a reactive plasticizer, which can effectively ensure the processability of raw materials during processing, and the raw materials are evenly mixed; and ethylene propylene rubber, cis-1,4-polyisoprene and trans-1,4-polyisoprene can form a uniform whole during the vulcanization reaction, effectively improving the mechanical properties of insulating materials; In addition, the coordination of cis-1,4-polyisoprene, trans-1,4-polyisoprene and talcum powder effectively improves the electrical insulation performance, dielectric properties and AC breakdown resistance of insulating materials. In addition, the raw materials prepared in this application are all environmentally friendly materials, without toxic and harmful substances such as lead tetroxide and lead stearate. DETAILED DESCRIPTION

[0043] Below in conjunction with the embodiments and examples, the present application is further described in detail. These embodiments and examples are only used to illustrate the present application and are not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the understanding of the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms, and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the present application, and the equivalent form obtained also falls within the protection scope of the present application. In addition, in the description below, a large number of specific details are given in order to provide a more comprehensive understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0045] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0046] In this application, the terms "first", "second", etc. in "the first aspect", "the second aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0047] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0048] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for a broad range of quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0049] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the invention purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0050] In traditional technology, the mechanical properties of EPDM can be effectively improved by introducing reinforcing agents such as white carbon black into EPDM. However, the addition of white carbon black will affect the processing performance and insulation performance of the rubber, resulting in the EPDM material being unable to meet the insulation performance requirements of medium and high voltages. In addition, ethylene-octene copolymers with similar structures can be introduced into EPDM to fully disperse and combine the raw materials in the preparation, thereby improving the insulation and dielectric properties of the insulating material. However, after the finished cable is extruded, it is easy to cause deformation of the insulating layer in the insulating core, posing a potential safety hazard. The present application study found that by introducing cis-1,4-butadiene rubber, trans-1,4-polyisoprene and talc into EPDM, cis-1,4-butadiene rubber and trans-1,4-polyisoprene can improve the dielectric properties and electrical insulation properties of the rubber, and cis-1,4-butadiene rubber and trans-1,4-polyisoprene have good compatibility with EPDM and can form a uniform whole during the vulcanization process, thereby improving the insulation properties of the rubber; in addition, the introduction of talc can effectively improve the AC breakdown resistance of the rubber, and by introducing cis-1,4-butadiene rubber, trans-1,4-polyisoprene and talc into EPDM, the mechanical properties, processing properties and insulation properties of the rubber can be synergistically improved.

[0051] In a first aspect, the present application provides an insulating material, wherein raw materials for preparing the insulating material include:

[0052] Ethylene propylene rubber, butadiene rubber, trans-1,4-polyisoprene, talc, dielectric agent, filler, coupling agent, antioxidant, vulcanizing agent and activator.

[0053] The present application uses ethylene propylene rubber, cis-1,4-butyl rubber, trans-1,4-polyisoprene and talcum powder for synergistic combination. Both cis-1,4-butyl rubber and trans-1,4-polyisoprene are non-polar materials and have good compatibility with ethylene propylene rubber. During the processing, the processability of the raw materials can be effectively guaranteed and the raw materials can be mixed evenly. Moreover, during the vulcanization reaction, ethylene propylene rubber, cis-1,4-butyl rubber and trans-1,4-polyisoprene can form a uniform whole, effectively improving the mechanical properties of the insulating material. In addition, the combination of cis-1,4-butyl rubber, trans-1,4-polyisoprene and talcum powder effectively improves the electrical insulation performance, dielectric performance and AC breakdown resistance of the insulating material.

[0054] It can be understood that dielectric properties refer to the ability of a material to store and dissipate electrical energy under an electric field, and measure the electric field strength inside the insulating material, that is, the voltage distribution inside the insulating material. Insulation performance refers to the electric field strength that the insulating material in the cable can withstand, that is, the voltage withstand capability of the cable under the working voltage.

[0055] In some embodiments, the raw materials of the insulating material include, by weight:

[0056] 100 parts of ethylene propylene rubber;

[0057] 10 to 20 parts of butadiene rubber;

[0058] 8 to 12 parts of trans-1,4-polyisoprene;

[0059] 25~40 parts of talcum powder;

[0060] Dielectric agent 5~10 parts;

[0061] 25~40 parts of filler;

[0062] 0.4~0.8 parts of coupling agent;

[0063] 2~4 parts of antioxidant;

[0064] 2 to 8 parts of vulcanizing agent; and

[0065] Activator 9~14 parts.

[0066] For example, the mass fraction of butadiene rubber can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts. The mass fraction of trans-1,4-polyisoprene can be 8.0 parts, 8.5 parts, 9.0 parts, 9.5 parts, 10.0 parts, 10.5 parts, 11.0 parts, 11.5 parts or 12.0 parts. The mass fraction of talc can be 25 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts or 40 parts. The mass fraction of dielectric agent can be 5.0 parts, 5.5 parts, 6.0 parts, 6.5 parts, 7.0 parts, 7.5 parts, 8.0 parts, 8.5 parts, 9.0 parts, 9.5 parts or 10.0 parts. The weight fraction of filler can be 25 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, 38 parts or 40 parts. The weight fraction of coupling agent can be 0.40 parts, 0.44 parts, 0.48 parts, 0.52 parts, 0.56 parts, 0.60 parts, 0.64 parts, 0.68 parts, 0.72 parts, 0.76 parts or 0.80 parts. The weight fraction of antioxidant can be 2.0 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3.0 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts or 4.0 parts. The mass fraction of vulcanizing agent can be 2.0 parts, 2.5 parts, 3.0 parts, 3.5 parts, 4.0 parts, 4.5 parts, 5.0 parts, 5.5 parts, 6.0 parts, 6.5 parts, 7.0 parts, 7.5 parts or 8.0 parts. The mass fraction of activating agent can be 9.0 parts, 9.5 parts, 10.0 parts, 10.5 parts, 11.0 parts, 11.5 parts, 12.0 parts, 12.5 parts, 13.0 parts, 13.5 parts or 14.0 parts.

[0067] The present application limits the mass fraction of raw materials for preparing insulating materials so that the raw materials cooperate and work synergistically with each other, thereby preparing insulating materials with excellent dielectric properties and mechanical properties.

[0068] It is understood that the dielectric agent refers to a material that can improve the dielectric properties of an insulating material.

[0069] In some embodiments, the EPDM rubber includes at least one of EPDM dipolymer and EPDM terpolymer.

[0070] Optionally, the EPDM rubber includes EPDM dipolymer and EPDM terpolymer. Based on 100 parts by total mass of the EPDM rubber, the EPDM rubber includes:

[0071] 40 to 60 parts of EPDM rubber; and

[0072] 40~60 parts of EPDM rubber.

[0073] For example, the mass fraction of EPDM is 40, 42, 44, 46, 48, 50, 52, 54, 56, 58 or 60. The mass fraction of EPDM is 40, 42, 44, 46, 48, 50, 52, 54, 56, 58 or 60.

[0074] In the present application, EPDM is prepared by using EPDM and EPDM, which has the advantages of fast vulcanization speed, good heat resistance, etc. If only EPDM or EPDM is used, not only the vulcanization speed is slow, but also the heat resistance is poor.

[0075] In some embodiments, the talc comprises talc modified with a silane coupling agent, wherein the silane coupling agent may be at least one of octyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane and vinyltriethoxysilane.

[0076] The present application adopts silane coupling agent to modify talc powder, which can increase the compatibility of materials and improve the mechanical strength and heat resistance of materials, and can avoid problems such as poor activity of talc powder, reduced mechanical properties of rubber and formation of concentrated breakdown points.

[0077] Exemplarily, a method for preparing the above-mentioned silane coupling agent modified talc is provided, comprising:

[0078] The talc powder and the silane coupling agent are mixed and then heated to make the silane coupling agent adhere to the talc powder, thereby obtaining the silane coupling agent modified talc powder.

[0079] Optionally, the stirring speed during the mixing process is 30 rpm to 50 rpm.

[0080] Optionally, the heating temperature is 70° C. to 90° C., and the heating time is 0.5 h to 1.5 h.

[0081] Alternatively, the silane coupling agent may be added to the talc in the form of a spray.

[0082] In some embodiments, the average particle size of the talc is 3 μm to 5 μm, for example, 3.0 μm, 3.2 μm, 3.4 μm, 3.6 μm, 3.8 μm, 4.0 μm, 4.2 μm, 4.4 μm, 4.6 μm, 4.8 μm or 5.0 μm.

[0083] The present application controls the average particle size of talcum powder, which can effectively maintain the insulating properties of the insulating material. If the particle size is relatively large, a conductive channel may be formed inside the material, thereby reducing the electrical insulating properties of the material.

[0084] In some embodiments, the weight average molecular weight of the trans-1,4-polyisoprene is 30,000 to 50,000, for example, 30,000, 32,000, 34,000, 36,000, 38,000, 40,000, 42,000, 44,000, 46,000, 48,000, or 50,000.

[0085] The present application controls the weight average molecular weight of trans-1,4-polyisoprene so that it has a good plasticizing effect, thereby ensuring that the insulating material has excellent mechanical properties and processing properties and avoiding problems such as difficulty in rubber extrusion.

[0086] In some embodiments, the dielectric agent includes at least one of polyethylene wax, butadiene rubber and trans-1,4-polyisoprene, preferably polyethylene wax, and optionally, the average molecular weight of the polyethylene wax is 2000-4000.

[0087] The present application adopts polyethylene wax as a dielectric agent, which has excellent dielectric properties and insulating properties, and can improve the dielectric properties and electrical insulation properties of insulating materials; at the same time, polyethylene wax can also be used as a processing aid, which is beneficial to the dispersion of various powders.

[0088] In some embodiments, the filler includes at least one of calcined modified kaolin, white carbon black and montmorillonite, preferably calcined modified kaolin, which is understood to be calcined at a temperature of 800-900°C, for example, 850°C.

[0089] Optionally, the average particle size of the calcined modified kaolin is 2 μm to 4 μm, for example, 2.0 μm, 2.2 μm, 2.4 μm, 2.6 μm, 2.8 μm, 3.0 μm, 3.2 μm, 3.4 μm, 3.6 μm, 3.8 μm or 4.0 μm.

[0090] The present application uses calcined modified kaolin as a filler, which can improve the insulation performance and mechanical properties and avoid problems such as insulation breakdown.

[0091] In some embodiments, the coupling agent includes at least one of γ-aminopropyltriethoxysilane, vinyltri(β-methoxyethoxy)silane, and vinyltriethoxysilane.

[0092] Optionally, the coupling agent includes γ-aminopropyltriethoxysilane and vinyltri(β-methoxyethoxy)silane. Further optionally, the mass ratio of γ-aminopropyltriethoxysilane to vinyltri(β-methoxyethoxy)silane is 1:(1.3~1.7), for example, it can be 1:1.3, 1:1.4, 1:1.5, 1:1.6 or 1:1.7, and can be 1:1.5.

[0093] The present application combines a coupling agent including γ-aminopropyltriethoxysilane and vinyltri(β-methoxyethoxy)silane with ethylene-propylene rubber, butadiene rubber and trans-1,4-polyisoprene to synergistically improve the comprehensive performance of the rubber compound.

[0094] In some embodiments, the antioxidant includes at least one of 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine and 2,2,4-trimethyl-1,2-dihydroquinoline polymer.

[0095] Optionally, the antioxidant includes 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine; further optionally, the mass ratio of the 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine is 1:(0.8~1.2), for example, it can be 1:0.8, 1:0.9, 1:1.0, 1:1.1 or 1:1.2, and can be optionally 1:1.

[0096] The antioxidant of the present application includes a combination of 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, which has the advantage of synergistic protection and can greatly improve the anti-aging ability and insulation performance of the material.

[0097] In some embodiments, the vulcanizing agent includes a primary vulcanizing agent and an auxiliary vulcanizing agent.

[0098] Optionally, the primary vulcanizing agent includes dicumyl peroxide.

[0099] Optionally, the co-vulcanizing agent includes at least one of liquid polybutadiene and N,N-m-phenylene-bismaleimide.

[0100] Optionally, the vulcanizing agent includes liquid polybutadiene and dicumyl peroxide; further optionally, the mass ratio of the liquid polybutadiene to dicumyl peroxide is 1:(0.8-2), for example, it can be 1:0.8, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1.8 or 1:2.0.

[0101] The curing agent of the present application includes a combination of liquid polybutadiene and diisopropylbenzene peroxide, which can increase the curing speed of the material and has good scorch safety performance. Among them, the liquid polybutadiene can be used as a plasticizer before the rubber is vulcanized to reduce the Mooney viscosity of the rubber and improve the processability. During the vulcanization, it can be used as a vulcanizing agent to increase its degree of vulcanization and give the rubber excellent mechanical properties.

[0102] In some embodiments, the weight average molecular weight of the liquid polybutadiene is 700-1400, for example, 700, 800, 900, 1000, 1100, 1200, 1300 or 1400.

[0103] In some embodiments, the activator includes at least one of zinc oxide, stearic acid, and zinc stearate.

[0104] Optionally, the activator comprises zinc oxide and stearic acid; further optionally, the mass ratio of the zinc oxide to stearic acid is (2-8): 1. The zinc oxide may be indirect zinc oxide.

[0105] Optionally, the mass purity of zinc oxide is ≥99.7%. The present application uses high-purity zinc oxide, which will not introduce impurities into the rubber material, thereby avoiding the presence of impurities causing partial discharge anomalies and affecting the overall insulation performance of the insulating material.

[0106] A second aspect of the present application provides a method for preparing the insulating material according to the first aspect, the method comprising:

[0107] The ethylene-propylene rubber, the butadiene rubber, the trans-1,4-polyisoprene, the talc, the dielectric agent, the filler, the coupling agent, the antioxidant, the vulcanizing agent and the activator are mixed to prepare the insulating material.

[0108] Exemplarily, a method for preparing the above insulating material is provided, comprising:

[0109] S1, mixing EPDM rubber, EPDM rubber and butadiene rubber;

[0110] S2, then add antioxidant, activator and dielectric agent, and mix until the rubber compound is agglomerated;

[0111] S3, continue to add the first vulcanizing agent, trans-1,4-polyisoprene, coupling agent, talcum powder and filler, and mix until the rubber compound is agglomerated.

[0112] S4, heating the rubber compound to 120°C~130°C, and then discharging the rubber compound to the screw extruder at 90°C~110°C;

[0113] S5, the temperature in the screw extruder is 90℃~100℃, and after extrusion, it enters the granulator and is cooled to obtain rubber particles;

[0114] S6. When the rubber particles are kneaded to 75°C to 85°C, a second vulcanizing agent is added and the kneading temperature is raised to 90°C to 95°C;

[0115] S7. Extruding and granulating the mixed rubber particles at a discharge temperature of 80° C. to 85° C., wherein the temperature during the extrusion and granulation process is 85° C. to 90° C., to prepare the insulating material.

[0116] The third aspect of the present application provides a use of the insulating material as described in the first aspect in the preparation of power transmission products.

[0117] A fourth aspect of the present application provides a cable, comprising the insulating material as described in the first aspect.

[0118] In some embodiments, the cable includes a conductor and an insulating layer and a sheath layer covering the conductor, and the material of the insulating layer includes the insulating material.

[0119] The embodiments of the present application will be described in detail below in conjunction with examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance provided in the present application, and can also be based on the experimental manual or normal conditions in this area, can also be based on the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0120] Example 1

[0121] Weigh the preparation raw materials according to mass fractions, including:

[0122] 50 parts of EPDM rubber;

[0123] 50 parts of EPDM rubber;

[0124] 15 parts of butadiene rubber;

[0125] 10 parts of trans-1,4-polyisoprene;

[0126] 40 parts of talcum powder;

[0127] Dielectric agent 8 parts;

[0128] 35 parts of filler;

[0129] 0.6 parts of coupling agent;

[0130] 4 parts of antioxidant;

[0131] 8 parts of vulcanizing agent; and

[0132] 12 parts of activator.

[0133] Among them, the weight average molecular weight of trans-1,4-polyisoprene is 40000. The average particle size of talc is 4μm. The dielectric agent is polyethylene wax, the melting point of polyethylene wax is 110℃, the Brookfield viscosity is 30cps, and the weight average molecular weight is 2000. The filler is calcined modified kaolin with an average particle size of 3μm. The coupling agent is γ-aminopropyltriethoxysilane and vinyltri(β-methoxyethoxy)silane in a mass ratio of 1:1.5. The antioxidant is 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine in a mass ratio of 1:1. The vulcanizing agent is liquid polybutadiene and dicumyl peroxide in a mass ratio of 1:1, and the weight average molecular weight of the liquid polybutadiene is 1000. The activating agent is zinc oxide and stearic acid in a mass ratio of 7:1, and the mass purity of the zinc oxide is 99.7%.

[0134] The preparation method comprises:

[0135] (1) Add EPDM rubber, EPDM rubber and 1,4-butadiene rubber into the first internal mixer and mix for half a minute;

[0136] (2) Continue to add the antioxidant, zinc oxide, stearic acid and polyethylene wax into the first internal mixer and mix until the rubber compound is agglomerated;

[0137] (3) adding liquid polybutadiene, trans-1,4-polyisoprene, coupling agent, talc and calcined kaolin into the first internal mixer and mixing until the rubber compound is agglomerated;

[0138] (4) Continue mixing for 2 minutes until the rubber temperature reaches 125°C, and discharge the rubber to the first double-cone feeding port. The double-cone temperature is controlled at 100°C.

[0139] (5) The mixed rubber is sent to a 150 single-screw extruder with a granulator head through a double cone; the temperatures of each zone of the single-screw extruder are 90°C, 90°C, 90°C, and 100°C, respectively. A filter is installed in front of the honeycomb plate at the granulator head, and the filter combination is 60 mesh + 80 mesh + 60 mesh;

[0140] (6) After the rubber particles are extruded by a 150 single-screw extruder, a blower is used to send the rubber particles into a spiral cooling tower. After cooling, a blower is used to send the rubber particles into a silo;

[0141] (7) Discharge an appropriate amount of rubber particles through the discharge valve below the silo and put them into the second internal mixer;

[0142] (8) When the temperature rises to 80°C, add the vulcanizing agent diisopropylbenzene peroxide into the second internal mixer;

[0143] (9) When the temperature rises to 90°C, discharge the rubber material to the second double cone feeding port, and the double cone temperature is controlled at 85°C;

[0144] (10) The vulcanized rubber compound is sent to a 150 single-screw extruder with a granulator head through a double cone; the temperatures of each zone of the single-screw extruder are 90°C, 85°C, 85°C, and 85°C. A filter is installed in front of the honeycomb plate at the granulator head, and the filter combination is 80 mesh + 80 mesh;

[0145] (11) After extrusion and granulation by a 150 single-screw extruder, the rubber particles are sent to a spiral cooling tower by a blower, and after cooling, the rubber particles are sent to a silo by a blower;

[0146] (12) The rubber particles in the silo are packaged according to demand to prepare insulating materials.

[0147] Example 2

[0148] The insulating material is prepared according to the method of Example 1, the only difference being that the raw materials for preparation include:

[0149] 40 parts of EPDM rubber;

[0150] 60 parts of EPDM rubber;

[0151] 10 parts of butadiene rubber;

[0152] 8 parts of trans-1,4-polyisoprene;

[0153] 25 parts of talcum powder;

[0154] 5 parts of dielectric agent;

[0155] 40 parts of filler;

[0156] 0.4 parts of coupling agent;

[0157] 2 parts of antioxidant;

[0158] 6 parts of vulcanizing agent; and

[0159] Activator 9 parts.

[0160] Among them, the weight average molecular weight of trans-1,4-polyisoprene is 30,000. The average particle size of talc is 3 μm. The filler is calcined modified kaolin with an average particle size of 2 μm. The coupling agent is γ-aminopropyltriethoxysilane and vinyltri(β-methoxyethoxy)silane in a mass ratio of 1.4:1. The antioxidant is 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine in a mass ratio of 1:1. The vulcanizing agent is liquid polybutadiene and diisopropylbenzene peroxide in a mass ratio of 1:2, and the weight average molecular weight of liquid polybutadiene is 1400. The activator is zinc oxide and stearic acid in a mass ratio of 6:1.

[0161] Example 3

[0162] The insulating material is prepared according to the method of Example 1, the only difference being that the raw materials for preparation include:

[0163] 60 parts of EPDM rubber;

[0164] 40 parts of EPDM rubber;

[0165] 20 parts of butadiene rubber;

[0166] 12 parts of trans-1,4-polyisoprene;

[0167] 40 parts of talcum powder;

[0168] Dielectric agent 10 parts;

[0169] Filler 25 parts;

[0170] 0.8 parts of coupling agent;

[0171] 4 parts of antioxidant;

[0172] 8 parts of vulcanizing agent; and

[0173] 14 parts of activator.

[0174] Among them, the weight average molecular weight of trans-1,4-polyisoprene is 50000. The average particle size of talc is 5μm. The filler is calcined modified kaolin with an average particle size of 4μm. The coupling agent is γ-aminopropyltriethoxysilane and vinyltri(β-methoxyethoxy)silane in a mass ratio of 1.5:1. The antioxidant is 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine in a mass ratio of 1:0.9. The vulcanizing agent is liquid polybutadiene and diisopropylbenzene peroxide in a mass ratio of 1:0.9, and the weight average molecular weight of liquid polybutadiene is 1200. The activator is zinc oxide and stearic acid in a mass ratio of 5:2.

[0175] Example 4

[0176] The insulating material is prepared according to the method of Example 1, except that the ethylene-propylene rubber comprises:

[0177] 20 parts of EPDM rubber; and

[0178] 80 parts of EPDM rubber.

[0179] Example 5

[0180] The insulating material is prepared according to the method of Example 1, except that the ethylene-propylene rubber comprises:

[0181] 80 parts of EPDM rubber; and

[0182] 20 parts of EPDM rubber.

[0183] Example 6

[0184] The insulating material was prepared according to the method of Example 1, the only difference being that the talc powder was modified by a silane coupling agent, the mass ratio of the silane coupling agent to the talc powder was 0.5:100, and the silane coupling agent was γ-methacryloxypropylmethyldimethoxysilane.

[0185] Example 7

[0186] The insulating material was prepared according to the method of Example 1, except that the average particle size of the talc powder was 8 μm.

[0187] Example 8

[0188] The insulating material was prepared according to the method of Example 1, except that the average particle size of the talc powder was 1 μm.

[0189] Example 9

[0190] An insulating material was prepared according to the method of Example 1, except that the weight average molecular weight of trans-1,4-polyisoprene was 20,000.

[0191] Example 10

[0192] An insulating material was prepared according to the method of Example 1, except that the weight average molecular weight of trans-1,4-polyisoprene was 60,000.

[0193] Embodiment 11

[0194] An insulating material was prepared according to the method of Example 1, except that the filler was replaced with an equal mass of white carbon black.

[0195] Example 12

[0196] An insulating material was prepared according to the method of Example 1, except that the coupling agent was replaced by γ-aminopropyltriethoxysilane.

[0197] Embodiment 13

[0198] An insulating material was prepared according to the method of Example 1, except that the coupling agent was replaced by vinyl tris(β-methoxyethoxy)silane.

[0199] Embodiment 14

[0200] An insulating material was prepared according to the method of Example 1, except that the antioxidant was replaced by 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane.

[0201] Embodiment 15

[0202] An insulating material was prepared according to the method of Example 1, except that the antioxidant was replaced by 4,4'-bis(α,α-dimethylbenzyl)diphenylamine.

[0203] Example 16

[0204] An insulating material was prepared according to the method of Example 1, the only difference being that the antioxidant was replaced by antioxidant RD and antioxidant MB in a mass ratio of 1:1.

[0205] Embodiment 17

[0206] An insulating material was prepared according to the method of Example 1, except that the vulcanizing agent was replaced by dicumyl peroxide and triallyl isocyanurate in a mass ratio of 1:1.

[0207] Comparative Example 1

[0208] The insulating material was prepared according to the method of Example 1, except that no butadiene rubber was added.

[0209] Comparative Example 2

[0210] An insulating material was prepared according to the method of Example 1, except that no trans-1,4-polyisoprene was added.

[0211] Comparative Example 3

[0212] An insulating material was prepared according to the method of Example 1, except that no talc was added.

[0213] Comparative Example 4

[0214] An insulating material was prepared according to the method of Example 1, except that trans-1,4-polyisoprene was replaced with an equal mass fraction of paraffin oil.

[0215] Comparative Example 5

[0216] An insulating material was prepared according to the method of Example 1, except that talc was replaced with kaolin of the same mass fraction.

[0217] The insulating materials prepared in the above embodiments and comparative examples were subjected to performance tests, and the testing method included:

[0218] The mechanical properties test is carried out in accordance with GB / T2951.11-2008 standard;

[0219] The air heat aging test was carried out according to GB / T2951.12-2008 standard, and the test conditions were: 135℃×10 days;

[0220] Insulation and dielectric properties tests refer to GB / T1410-2006 and GB / T 3048-2007;

[0221] The air bomb aging test was carried out according to GB / T2951.12-2008 standard, test conditions: 127±2℃×40h;

[0222] The water absorption performance test was carried out in accordance with GB / T2951.13-2008 standard, and the test conditions were: weight method, 85°C, 336h.

[0223] The test results are shown in Tables 1 to 5.

[0224] Table 1

[0225]

[0226] Table 2

[0227]

[0228] Table 3

[0229]

[0230] Table 4

[0231]

[0232] Table 5

[0233]

[0234] From the above table we can see that:

[0235] (1) Compared with Examples 4-5, it can be seen that the EPDM rubber and EPDM rubber of specific composition used in the present application have the advantages of fast vulcanization speed and good heat aging resistance.

[0236] (2) Compared with Example 6, it can be seen that the talc powder modified with a silane coupling agent in the present application has the advantages of excellent mechanical properties, high breakdown strength, good heat aging resistance, etc.

[0237] (3) Compared with Examples 7-8, Example 1 shows that the particle size of talcum powder is controlled in the present application, which has the advantage of high breakdown strength. If the particle size is relatively large or small, the talcum powder is prone to defects or agglomeration, which in turn causes defect amplification in the aging test.

[0238] (4) Compared with Examples 9-10, it can be seen that the molecular weight of trans-1,4-polyisoprene is controlled in the present application so that it has a good plasticizing effect, thereby ensuring that the insulating material has excellent mechanical properties and processing properties, and avoiding the occurrence of problems such as difficulty in rubber extrusion.

[0239] (5) Compared with Example 1, it can be seen that the calcined modified kaolin used in the present application has the advantages of electrical insulation, excellent dielectric properties, heat aging resistance, etc. Although white carbon black has a better reinforcing effect than calcined modified kaolin in conventional technology, calcined modified kaolin can cooperate with EPDM, cis-1,4-polyisoprene to improve the overall performance.

[0240] (6) Compared with Examples 12-13, it can be seen that the selection of the coupling agent combination in the present application cooperates with EPDM, cis-1,4-polyisoprene to improve the overall performance, and has the advantages of high strength and good aging resistance.

[0241] (7) Compared with Examples 14-16, it can be seen that the selection of the antioxidant combination in the present application cooperates with EPDM, cis-1,4-polyisoprene to improve the overall performance and has the advantages of excellent aging resistance.

[0242] (8) By comparing Example 1 with Example 17, it can be seen that the selection of the vulcanizing agent combination of the present application has the advantages of good vulcanization effect and excellent comprehensive performance.

[0243] (9) Compared with Comparative Examples 1-5, it can be seen that in the present application, EPDM, cis-1,4-butyl rubber, trans-1,4-polyisoprene and talcum powder are synergistically formulated. Both cis-1,4-butyl rubber and trans-1,4-polyisoprene are non-polar materials and have good compatibility with EPDM. During the processing, the processability of the raw materials can be effectively guaranteed and the raw materials can be mixed evenly. Moreover, during the vulcanization reaction, EPDM, cis-1,4-butyl rubber and trans-1,4-polyisoprene can form a uniform whole, which effectively improves the mechanical properties of the insulating material. In addition, the combination of cis-1,4-butyl rubber, trans-1,4-polyisoprene and talcum powder effectively improves the electrical insulation performance and AC breakdown resistance of the insulating material.

[0244] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0245] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. An insulating material, characterized in that: The raw materials of the insulating material include, by weight: Wherein, the filler is at least one of calcined modified kaolin, white carbon black and montmorillonite; and the dielectric agent is polyethylene wax.

2. The insulating material according to claim 1, characterized in that The EPDM rubber includes at least one of EPDM dipolymer rubber and EPDM terpolymer rubber.

3. The insulating material according to claim 1, characterized in that The EPDM rubber includes EPDM dipolymer and EPDM terpolymer. Based on 100 parts by total weight of the EPDM rubber, the EPDM rubber includes: 40 to 60 parts of EPDM rubber; and 40 to 60 parts of EPDM rubber.

4. The insulating material according to claim 1, characterized in that The insulating material satisfies at least one of the following conditions: (1) The talc powder includes talc powder modified with a silane coupling agent; (2) The average particle size of the talc is 3 μm to 5 μm; (3) The weight average molecular weight of the trans-1,4-polyisoprene is 30,000 to 50,000.

5. The insulating material according to claim 1, characterized in that The average particle size of the calcined modified kaolin is 2 μm to 4 μm.

6. The insulating material according to claim 1, characterized in that The coupling agent includes at least one of γ-aminopropyltriethoxysilane, vinyltri(β-methoxyethoxy)silane and γ-methacryloxypropyltrimethoxysilane.

7. The insulating material according to claim 1, characterized in that The coupling agents include γ-aminopropyltriethoxysilane and vinyltri(β-methoxyethoxy)silane.

8. The insulating material according to claim 7, characterized in that The mass ratio of the γ-aminopropyltriethoxysilane to vinyltri(β-methoxyethoxy)silane is 1:(1.3-1.7).

9. The insulating material according to claim 1, characterized in that The antioxidant includes at least one of 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine and 2,2,4-trimethyl-1,2-dihydroquinoline polymer.

10. The insulating material according to claim 1, characterized in that The antioxidant includes 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine.

11. The insulating material according to claim 10, characterized in that The mass ratio of the 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane to 4,4'-bis(α,α-dimethylbenzyl)diphenylamine is 1:(0.8-1.2).

12. The insulating material according to claim 1, characterized in that The vulcanizing agent includes a main vulcanizing agent and an auxiliary vulcanizing agent.

13. The insulating material according to claim 12, characterized in that The main vulcanizing agent includes dicumyl peroxide.

14. The insulating material according to claim 12, characterized in that The auxiliary vulcanizing agent includes at least one of liquid polybutadiene and N,N-m-phenylene-bismaleimide.

15. The insulating material according to claim 12, characterized in that The vulcanizing agent includes liquid polybutadiene and dicumyl peroxide.

16. The insulating material according to claim 15, characterized in that The mass ratio of the liquid polybutadiene to dicumyl peroxide is 1:(0.8-2).

17. The insulating material according to any one of claims 1 to 16, characterized in that: The activator includes at least one of zinc oxide, stearic acid and zinc stearate.

18. The insulating material according to claim 17, characterized in that The activators include zinc oxide and stearic acid.

19. The insulating material according to claim 18, characterized in that The mass ratio of the zinc oxide to stearic acid is (2-8):

1.

20. A method for preparing the insulating material according to any one of claims 1 to 19, characterized in that: The preparation method comprises: The ethylene-propylene rubber, the butadiene rubber, the trans-1,4-polyisoprene, the talc, the dielectric agent, the filler, the coupling agent, the antioxidant, the vulcanizing agent and the activator are mixed to prepare the insulating material.

21. Use of the insulating material according to any one of claims 1 to 19 in the preparation of power transmission products.

22. A cable, characterized in that: The cable comprises the insulating material according to any one of claims 1-19.

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