Ethylene-propylene insulation material for 105 DEG C wind energy cable and preparation method of ethylene-propylene insulation material

Abstract

The ethylene-propylene insulating material for the 105 DEG C wind energy cable is prepared from the following raw materials in parts by weight: 100 parts of basic raw materials consisting of ethylene-propylene rubber and an elastomer, 2-4 parts of a vulcanizing agent, 1-2 parts of an assistant vulcanizing agent, 5-8 parts of an active agent, 20-40 parts of a filling agent, 60-80 parts of filler, 3-5 parts of an anti-aging agent, 3-5 parts of an antiozonant, 0.5-3 parts of a plasticizer and 0.5-2 parts of a coupling agent. The preparation method of the insulating material comprises the following steps: (1) weighing materials; (2) premixing; (3) mixing; and (4) extrusion molding. Through a specific formula and a preparation method, the insulating material not only has good high-temperature aging resistance, but also has excellent low-temperature performance and excellent processing extrusion performance, and a good extrusion effect can be achieved under a double-extrusion process.

Description

Technical Field

[0001] The invention belongs to the technical field of cables, and in particular relates to an ethylene propylene insulating material for a 105°C wind power cable and a preparation method thereof. Background Art

[0002] In recent years, the world has been concerned about the issue of climate change, and countries have paid more attention to the development of new energy. Whether it is the United States, Europe, Japan or emerging developing countries, they have actively formulated new energy development plans. As a new energy source, wind power generation is environmentally friendly, technologically mature, and globally feasible. It is being used more and more widely around the world. With the development and application of wind turbines, wind power cables are also widely used.

[0003] In the existing technology, the construction site selection trend of wind power generation equipment is towards high altitude areas. This places higher requirements on the weather resistance of the cables used, such as temperature resistance and ozone resistance. For production, good processing performance is also required. Summary of the invention

[0004] In view of the above problems, the present invention provides an ethylene propylene insulation material for 105°C wind power cable and a preparation method thereof. The insulation material has good high-temperature aging resistance, excellent low-temperature performance and excellent processing and extrusion performance.

[0005] 1) The insulation material must meet the aging test of the 105°C temperature level to ensure that the cable can work normally at a temperature of 105°C;

[0006] 2) The insulation material must be able to withstand low temperatures of -40°C and meet the requirements of normal temperature, low temperature, and high temperature torsion tests;

[0007] 3) The insulating material must have good processing properties and must ensure that good extrusion effects can be achieved in the double extrusion process.

[0008] In order to achieve the above objectives, the present invention needs to take the following into consideration:

[0009] 1) EPDM insulation meets the aging test of 105℃ temperature level:

[0010] It is necessary to ensure that the formula itself has a high degree of cross-linking and that the formula base material has sufficient aging resistance.

[0011] It is necessary to select suitable EPDM rubber (brand), i.e., EPDM rubber with low propylene content, few tertiary carbon atoms on the macromolecular chain, which is beneficial to the aging resistance of rubber, and EPDM rubber with low third monomer content;

[0012] Select antioxidants with high temperature resistance; the formula has a high degree of cross-linking.

[0013] 2) The insulation material needs to withstand low temperatures of -40°C. To meet the torsion test requirements of each temperature range, the base material is required to have good molecular chain flexibility.

[0014] 3) The material is required to have good discharge stability and an ethylene content of more than 60 to ensure good processing and vulcanization properties. At the same time, the Mooney viscosity of the material is controlled and the plasticizer system of the formula is adjusted.

[0015] Based on the above ideas, the present invention proposes the following solution.

[0016] An ethylene-propylene insulating material for 105°C wind power cable, the ingredients of which are calculated by weight, and the raw materials include:

[0017] 100 parts of basic raw materials consisting of EPDM and elastomer,

[0018] 2 to 4 parts of vulcanizing agent,

[0019] 1-2 parts of vulcanizing agent,

[0020] 5-8 parts of active agent,

[0021] 20-40 parts of filler,

[0022] 60-80 parts of filler,

[0023] 3-5 parts of antioxidant,

[0024] 3-5 parts of antiozonant,

[0025] Plasticizer 0.5-3 parts,

[0026] 0.5-2 parts of coupling agent,

[0027] In the basic raw material, the mass fraction of EPDM is 60 to 80 parts, and the balance is elastomer;

[0028] EPDM is EPDM, the ethylene content is 60 mol% or more, the third monomer content is required to be 0.1% to 2%, and the Mooney viscosity range is 19 to 45;

[0029] The elastomer is a thermoplastic elastomer, wherein the most preferred type of elastomer is a metallocene-catalyzed POE elastomer;

[0030] The vulcanizing agent is a peroxide vulcanizing agent, preferably di-tert-butyl peroxide isopropylbenzene BIPB;

[0031] The auxiliary vulcanizing agent is triallyl isocyanuric acid TAIC or trimethylolpropane trimethacrylate (TMPTMA) or diallyl maleate (DAM).

[0032] During the rubber vulcanization process, the preferred TAIC in this scheme can undergo a cross-linking reaction with rubber molecules to improve the cross-linking density and heat resistance, aging resistance and other properties of the vulcanized rubber. It is particularly suitable for high-temperature vulcanized rubber products, and can improve the strength, hardness, wear resistance, oil resistance and other properties of the rubber, while also reducing the compression permanent deformation of the rubber.

[0033] The preferred active agent of this scheme is zinc oxide, and the mesh number of zinc oxide particles is 325 mesh;

[0034] Zinc oxide improves cross-linking activity, increases cross-linking density, enhances anti-reversion, and improves the heat resistance and dynamic fatigue performance of EPDM insulation. Although zinc oxide has a negative charge, which makes it difficult to disperse in EPDM, the dispersibility of zinc oxide in EPDM insulation can be improved by using pre-granulated zinc oxide particle preparations; zinc oxide in EPDM insulation can improve the activity of vulcanization accelerators / co-vulcanizers, reduce the amount of accelerators, shorten the vulcanization cycle, speed up the vulcanization speed, improve the thermal conductivity of the vulcanized rubber, and make the vulcanization more thorough.

[0035] The active agent may also be zinc stearate or magnesium oxide, but in this formulation, the contribution to the reduction of the amount of the accelerator is not obvious.

[0036] The preferred antiozonant of this embodiment is microcrystalline wax.

[0037] When microcrystalline wax comes into contact with EPDM, a solid solution is formed between them. At higher temperatures, microcrystalline wax completely dissolves in EPDM; at lower temperatures, due to the poor solubility of microcrystalline wax in EPDM, the microcrystalline wax is supersaturated in EPDM. This supersaturated state causes the microcrystalline wax to continuously migrate from the inside of the rubber to the surface of the rubber, forming a uniform wax film. This wax film isolates the ozone in the atmosphere from contacting the rubber surface, thereby effectively preventing the oxidation of the rubber by ozone and avoiding the aging and degradation of the rubber.

[0038] The antiozonant can also be paraffin wax. However, the wax film formed by paraffin wax crystallizes into a loose, porous, brittle wax film that is easy to fall off the rubber surface. Compared with microcrystalline wax, ozone can easily penetrate this wax film and react with the double bonds of rubber molecules.

[0039] The preferred butyl stearate or glyceryl monostearate of this scheme, in addition to the plasticizing effect, can also be used as an external lubricant to promote the full diffusion of zinc oxide, and as a major vulcanization accelerator. Stearic acid plasticizers can significantly reduce the viscosity of the rubber, improve the process performance, and improve the plasticity of the rubber. This is because stearic acid has a greater impact on the rubber, which can significantly reduce the viscosity of the rubber, thereby improving the process performance. Stearic acid also plays the role of an external lubricant during rubber processing, which helps to improve the processing properties of rubber. Stearic acid reacts with zinc oxide or alkaline accelerators to promote its activity, play the role of a second accelerator, and accelerate the hardening process. Among them, butyl stearate has an obvious effect on improving the low temperature performance of the product.

[0040] The preferred vinyl tris (β-methoxyethoxy) silane of this scheme can improve the adhesion and compatibility between EPDM and inorganic filler, thereby improving the physical properties of EPDM and protecting the interface from moisture erosion. By combining with inorganic filler, this silane coupling agent can make the filler surface hydrophobic, improve the compatibility of filler and polymer, thereby making the dispersibility better, reducing the melting point, and making the processing of filled plastics easier. This also helps to improve the mechanical and electrical properties of EPDM. Vinyl tris (β-methoxyethoxy) silane can also shorten the mixing time, quickly extrude and improve the advantages of wear, and optimize the processing performance of EPDM.

[0041] The antioxidant is a compound of 4,4'-bis(α,α-dimethylbenzyl)diphenylamine and 2-mercaptobenzimidazole.

[0042] The two antioxidants can produce a synergistic effect when used together. They can capture free radicals through different pathways and mechanisms, and synergistically enhance the free radical scavenging ability; the synergistic effect of the two can improve the decomposition efficiency of peroxides, reduce the oxidative damage of peroxides to materials, and thus enhance the antioxidant properties of materials; the combination of the two can chelate metal ions together and enhance the chelating ability of metal ions. 4,4'-bis(α,α-dimethylbenzyl)diphenylamine can first form a complex with metal ions, and then 2-mercaptobenzimidazole can further combine with the metal ions in the complex to form a more stable complex. The synergistic effect can more effectively inhibit the catalytic effect of metal ions, reduce the occurrence of oxidation reactions, and improve the antioxidant capacity of materials.

[0043] The compounding ratio of antioxidant 4,4'-bis(α,α-dimethylbenzyl)diphenylamine (KY-405) and 2-mercaptobenzimidazole (MBI) can be 1:1 to 1:3. 1:1 is suitable for scenes requiring moderate antioxidant performance and anti-aging effects. 1:2 is suitable for scenes requiring higher antioxidant performance and anti-aging effects. 1:3 is suitable for scenes requiring extremely high antioxidant performance and anti-aging effects.

[0044] The filler in this solution is talcum powder; talcum powder can improve the physical and mechanical properties and scorch resistance of EPDM rubber. Talc powder can enhance the performance of the material by increasing the tensile strength, tensile stress and hardness of the rubber. Talc powder has stable chemical properties, acid resistance, alkali resistance, heat resistance, good electrical insulation, and good air permeability resistance. It can improve the processing performance of EPDM insulation material, making it easier to process and shape.

[0045] Kaolin can also be used as a filler, which can improve tensile strength and hardness, but its contribution to the processing performance of the product is not obvious.

[0046] The filler of this solution is calcined clay; calcined clay improves the physical and mechanical properties of EPDM insulation, including tear strength, wear resistance, low-temperature flexibility, etc., while maintaining good electrical properties.

[0047] Carbon black can also be used as filler, but its contribution to the low temperature performance of the product is not obvious.

[0048] The method for preparing the ethylene-propylene insulating material for 105°C wind power cable comprises the following steps:

[0049] 1) Weighing materials: Accurately weigh various materials according to the formula for use;

[0050] 2) Premixing: Premix the active agent, antioxidant and plasticizer in a horizontal ribbon mixer and fully premix them. After stirring, bag them for later use.

[0051] 3) Mixing:

[0052] 3.1) Mix the EPDM rubber and the elastomer in an internal mixer;

[0053] 3.2) mixing the premixed powder in step 2) with the antiozonant, the filler, the stuffing, the coupling agent and the mixed material obtained in step 3.1) in an internal mixer;

[0054] 3.3) The mixed material obtained in step 3.2) is removed from the internal mixer and mixed in an open mixer to obtain a rubber material;

[0055] 3.4) filtering the rubber material obtained in step 3.3), and then adding a vulcanizing agent and a vulcanizing agent to a kneader for mixing;

[0056] 3.5) The rubber material obtained in step 3.4) is stretched into thin tubes, packaged into triangles, cut into rolls, and then rolled to obtain a mixed material;

[0057] 4) Extrusion molding: After the material obtained in step 3.5) is left to stand for at least 24 hours, it is extruded to obtain the desired insulating material.

[0058] Specifically, in step 2), premixing for 10 minutes;

[0059] In step 3.1), the mixing time is 3 to 5 minutes, and the mixing temperature is controlled at 90 to 105°C;

[0060] In step 3.2), the mixing time is 5 to 10 minutes, and the mixing temperature is controlled within 130° C.;

[0061] In step 3.3), the mixture is placed in an open mixer and mixed for 25 to 35 seconds at a mixing temperature of 55 to 65° C.;

[0062] In step 3.4), the mixing temperature is controlled within 120° C. and the mixing time is 3 to 5 minutes. DETAILED DESCRIPTION

[0063] The present invention is further described below in conjunction with specific embodiments.

[0064] The invention discloses an ethylene-propylene insulating material for a 105-degree-C wind power cable. The raw materials thereof are calculated by weight: 100 parts of a basic raw material consisting of ethylene-propylene rubber and an elastomer, 2 to 4 parts of a vulcanizing agent, 1 to 2 parts of an auxiliary vulcanizing agent, 5 to 8 parts of an activating agent, 20 to 40 parts of a filling agent, 60 to 80 parts of a filler, 3 to 5 parts of an antioxidant, 3 to 5 parts of an antiozonant, 0.5 to 3 parts of a plasticizer, and 0.5 to 2 parts of a coupling agent.

[0065] Among the basic raw materials, the mass fraction of EPDM is 60 to 80 parts, and the balance is elastomer; the EPDM is EPDM, and its ethylene content is 60 mol% or more, the third monomer content is required to be 0.1% to 2%, and the Mooney viscosity range is 19 to 45; the elastomer is a thermoplastic elastomer; the vulcanizer is a peroxide vulcanizer; the co-vulcanizer is triallyl isocyanuric acid TAIC or trimethylolpropane trimethacrylate TMPTMA or diallyl maleate DAM; the antiozonant is a wax antiozonant; the plasticizer is a stearic acid plasticizer; and the coupling agent is a silane coupling agent.

[0066] The method for preparing the ethylene-propylene insulating material for 105°C wind power cable comprises the following steps:

[0067] 1) Weighing materials: Accurately weigh various materials according to the formula for use;

[0068] 2) Premixing: Premix the active agent, antioxidant and plasticizer in a horizontal ribbon mixer and fully premix them. After stirring, bag them for later use.

[0069] 3) Mixing:

[0070] 3.1) Mix the EPDM rubber and the elastomer in an internal mixer;

[0071] 3.2) mixing the premixed powder in step 2) with the antiozonant, the filler, the stuffing, the coupling agent and the mixed material obtained in step 3.1) in an internal mixer;

[0072] 3.3) The mixed material obtained in step 3.2) is removed from the internal mixer and mixed in an open mixer to obtain a rubber material;

[0073] 3.4) filtering the rubber material obtained in step 3.3), and then adding a vulcanizing agent and a vulcanizing agent to a kneader for mixing;

[0074] 3.5) The rubber material obtained in step 3.4) is stretched into thin tubes, packaged into triangles, cut into rolls, and then rolled to obtain a mixed material;

[0075] 4) Extrusion molding: After the material obtained in step 3.5) is left to stand for at least 24 hours, it is extruded to obtain the desired insulating material.

[0076] In step 2), premix for 10 minutes;

[0077] In step 3.1), the mixing time is 3 to 5 minutes, and the mixing temperature is controlled at 90 to 105°C;

[0078] In step 3.2), the mixing time is 5 to 10 minutes, and the mixing temperature is controlled within 130° C.;

[0079] In step 3.3), the mixture is placed in an open mixer and mixed for 25 to 35 seconds at a mixing temperature of 55 to 65° C.;

[0080] In step 3.4), the mixing temperature is controlled within 120° C. and the mixing time is 3 to 5 minutes.

[0081] The raw materials used in this experimental example are common raw materials for rubber insulation materials, as follows:

[0082] The model of EPDM is 3722 (EPDM 3722);

[0083] The elastomer is a metallocene-catalyzed POE elastomer;

[0084] The curing agent is di-tert-butyl peroxide isopropylbenzene BIPB;

[0085] The curing agent is triallyl isocyanuric acid TAIC;

[0086] The active agent is zinc oxide particles with a mesh size of 325 mesh;

[0087] The filler is talc;

[0088] The filler is calcined clay;

[0089] The antioxidant is a mixture of 4,4'-bis(α,α-dimethylbenzyl)diphenylamine and 2-mercaptobenzimidazole (1:1 to 1:3);

[0090] The antiozonant is microcrystalline wax (80#);

[0091] The plasticizer is butyl stearate or glyceryl monostearate;

[0092] The coupling agent was vinyltri(β-methoxyethoxy)silane.

[0093] In the preparation process of the insulating material in this experimental example:

[0094] In the step 3.2), the mixing mill is a 550 double-roll mixing mill;

[0095] In the step 3.3), the kneader is a 75L kneader;

[0096] In the step 3.4), the rubber is filtered by using a rubber filter, and the temperature of the rubber filter is controlled within 150° C.;

[0097] In the step 3.5), the thinning process is performed by a 550 double-roll mill, and the sheeting is performed by a three-roll sheet mill;

[0098] In the step 4), an extruder is used for extrusion.

[0099] In order to ensure product quality, the following process parameters are adopted:

[0100] In the step 3.1), the mixing time is 4 minutes, and the mixing temperature is controlled at 100°C ± 5°C;

[0101] In the step 3.2), the mixing time is 8 minutes, and the mixing temperature is controlled at 120±5°C;

[0102] In the step 3.3), the mixing time is 30±5s and the mixing temperature is 60±5°C;

[0103] In the step 3.4), the mixing temperature is controlled at 110±5° C., and the entire mixing process lasts for 3 minutes.

[0104] The formula of this experimental example is shown in Table 1:

[0105] Table 1

[0106]

[0107] The performance test of the obtained insulating material is shown in Table 2:

[0108] Table 2

[0109]

[0110] Compared with the prior art, the insulating material of the present invention has the following advantages: since the present invention uses EPDM rubber with low third monomer content and high ethylene content and elastomer blending, the material has excellent physical and mechanical properties. At the same time, the use of an antioxidant with a high temperature resistance grade ensures the material's excellent high-temperature heat-resistant oxygen aging performance, and the material can meet the aging requirement of 150°C × 7 days, thereby increasing the material's service life.

[0111] The curing agent selected is di-tert-butyl peroxide isopropylbenzene, or BIBP, which is suitable for high-temperature continuous vulcanization process; under high temperature conditions, BIBP will not accelerate rubber aging due to residual decomposition, thereby improving the high-temperature stability of the insulating material. In order to improve the degree of vulcanization of the insulating material and improve the physical and mechanical properties of the vulcanized rubber, a co-vulcanizing agent is added. The addition of a co-vulcanizing agent can inhibit the occurrence of side reactions such as chain scission and disproportionation of polymer molecules during the vulcanization process and improve the cross-linking efficiency. Therefore, after adding the triallyl isocyanurate co-vulcanizing agent with a functional group, the vulcanization speed is greatly accelerated, the cross-linking density is increased, and the temperature resistance of the vulcanized rubber is also improved.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the substantial technical content of the present invention. The substantial technical content of the present invention is broadly defined in the scope of the claims of the application. Any technical entity or method completed by others, if it is exactly the same as that defined in the scope of the claims of the application, or an equivalent variation, will be deemed to be included in the scope of the claims.

Claims

1. An ethylene-propylene insulating material for 105°C wind power cable, characterized in that: The ingredients are calculated by weight, and the raw materials include: 100 parts of basic raw materials consisting of EPDM and elastomer, 2 to 4 parts of vulcanizing agent, 1-2 parts of vulcanizing agent, 5-8 parts of active agent, 20-40 parts of filler, 60-80 parts of filler, 3-5 parts of antioxidant, 3-5 parts of antiozonant, Plasticizer 0.5-3 parts, 0.5-2 parts of coupling agent, In the basic raw material, the mass fraction of EPDM is 60 to 80 parts, and the balance is elastomer; EPDM is EPDM, the ethylene content is 60 mol% or more, the third monomer content is required to be 0.1% to 2%, and the Mooney viscosity range is 19 to 45; the elastomer is a thermoplastic elastomer; The vulcanizing agent is a peroxide vulcanizing agent; The co-vulcanizing agent is triallyl isocyanuric acid TAIC or trimethylolpropane trimethacrylate TMPTMA or diallyl maleate DAM; The antiozonant is a wax antiozonant; The plasticizer is a stearic acid plasticizer; The coupling agent is a silane coupling agent.

2. The 105°C wind power cable ethylene-propylene insulation material according to claim 1, characterized in that: The elastomer is a metallocene-catalyzed POE elastomer; The vulcanizing agent is di-tert-butyl peroxide isopropylbenzene BIPB; The vulcanizing agent is triallyl isocyanuric acid TAIC; The active agent is zinc oxide particles, the mesh size of which is 325 mesh; The filler is talc; The filler is calcined clay; The antioxidant is a compound of 4,4'-bis(α,α-dimethylbenzyl)diphenylamine and 2-mercaptobenzimidazole; The antiozonant is microcrystalline wax; The plasticizer is butyl stearate or glyceryl monostearate; The coupling agent is vinyltri(β-methoxyethoxy)silane.

3. The ethylene-propylene insulating material for 105°C wind power cable according to claim 1, characterized in that: The composition of the insulating material is calculated by weight, and the raw materials include: EPDM rubber 70 parts, Elastomer 30 parts, 2 parts of di-tert-butyl peroxide isopropylbenzene BIPB, Triallyl isocyanurate TAIC 1 part, 5 parts of zinc oxide granules, 20 parts of talcum powder, 70 parts of calcined clay, 3 parts of antioxidant, 4 parts of microcrystalline wax, 0.5 parts of plasticizer, 2 parts of vinyl tris(β-methoxyethoxy)silane.

4. A method for preparing ethylene-propylene insulation material for 105°C wind power cable according to any one of claims 1 to 3, characterized in that: The following steps are involved: 1) Weighing materials: Accurately weigh various materials according to the formula for use; 2) Premixing: Premix the active agent, antioxidant and plasticizer in a horizontal ribbon mixer and fully premix them. After stirring, bag them for later use. 3) Mixing: 3.1) Mix the EPDM rubber and the elastomer in an internal mixer; 3.2) mixing the premixed powder in step 2) with the antiozonant, the filler, the stuffing, the coupling agent and the mixed material obtained in step 3.1) in an internal mixer; 3.3) The mixed material obtained in step 3.2) is removed from the internal mixer and mixed in an open mixer to obtain a rubber material; 3.4) filtering the rubber material obtained in step 3.3), and then adding a vulcanizing agent and a vulcanizing agent to a kneader for mixing; 3.5) The rubber material obtained in step 3.4) is stretched into thin tubes, packaged into triangles, cut into rolls, and then rolled to obtain a mixed material; 4) Extrusion molding: After the material obtained in step 3.5) is left to stand for at least 24 hours, it is extruded to obtain the desired insulating material.

5. The method for preparing ethylene-propylene insulating material for 105°C wind power cable according to claim 4, characterized in that: In step 2), premix for 10 minutes; In step 3.1), the mixing time is 3 to 5 minutes, and the mixing temperature is controlled at 90 to 105°C; In step 3.2), the mixing time is 5 to 10 minutes, and the mixing temperature is controlled within 130° C.; In step 3.3), the mixture is placed in an open mixer and mixed for 25 to 35 seconds at a mixing temperature of 55 to 65° C.; In step 3.4), the mixing temperature is controlled within 120° C. and the mixing time is 3 to 5 minutes.

6. The method for preparing ethylene-propylene insulating material for 105°C wind power cable according to claim 4, characterized in that: In the step 3.2), the mixing mill is a 550 double-roll mixing mill; In the step 3.3), the kneader is a 75L kneader; In the step 3.4), the rubber is filtered by using a rubber filter, and the temperature of the rubber filter is controlled within 150° C.; In the step 3.5), the thinning process is performed by a 550 double-roll mill, and the sheeting is performed by a three-roll sheet mill; In the step 4), an extruder is used for extrusion.

7. The method for preparing ethylene-propylene insulation material for 105°C wind power cable according to claim 4, characterized in that: In the step 3.1), the mixing time is 4 minutes, and the mixing temperature is controlled at 100°C ± 5°C; In the step 3.2), the mixing time is 8 minutes, and the mixing temperature is controlled at 120±5°C; In the step 3.3), the mixing time is 30±5s and the mixing temperature is 60±5°C; In the step 3.4), the mixing temperature is controlled at 110±5° C., and the entire mixing process lasts for 3 minutes.

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