An electromagnetic shielding material, its preparation process, and an optoelectronic composite cable

Abstract

This application relates to the field of functional polymer materials, and in particular to an electromagnetic shielding material, its preparation process, and an optoelectronic composite cable; among them, for an electromagnetic shielding material, by weight, 25-35 parts of styrene-butadiene rubber, 10-15 parts of silicone rubber, 20-35 parts of metallocene polyolefin, 10-20 parts of carbon-based conductive filler, 0.5-1.5 parts of vulcanizing agent, and 0.5-1.5 parts of vulcanization accelerator; the carbon-based conductive filler is graphene and / or carbon nanotube; by using the compatibility of metallocene polyolefin, carbon-based conductive filler, styrene-butadiene rubber, and silicone rubber, the prepared electromagnetic shielding material has good anti-side pressure, bending strength, impact strength, and shielding effectiveness at the same time, reduces the interference of electromagnetic on the optical fiber, and reduces the side pressure on the optical fiber in the state of micro-bending of the optoelectronic composite cable, thereby improving the communication quality and stability of the optoelectronic composite cable.

Description

Technical Field

[0001] This application relates to the field of functional polymer materials, and particularly to an electromagnetic shielding material, its preparation process, and an optoelectronic composite cable. Background Art

[0002] Intelligent communication is a new type of communication method that combines artificial intelligence technology and communication technology. It aims to achieve a more efficient, convenient, and personalized communication experience through intelligent algorithms and systems. With the popularization of intelligent devices, the demand for power transmission is also increasing day by day. Intelligent communication is inseparable from the transmission of high-efficiency optical signals and electrical signals.

[0003] Traditional optical fiber cables and power cables are laid separately, which not only occupies a large amount of space but also has a high maintenance cost. Therefore, developing a composite cable that can simultaneously achieve optical fiber communication and power transmission has become an urgent need in the industry; an optoelectronic composite cable is a cable in which an optical cable and an electric wire are combined in one cable and has the ability to transmit electrical energy and optical communication.

[0004] At present, although there are some optoelectronic composite cable products on the market, they still have certain limitations in structural design and performance, such as low integration of optical fibers and cables, complex structure of composite cables, cumbersome preparation processes, signal interference between optical fibers and cables, poor signal transmission stability, weak anti-interference ability, etc.; and with the increasing demand for optoelectronic composite cables for intelligent communication, the equipment is becoming more and more miniaturized, and the optoelectronic composite cable also needs to be more compact and has a micro-bending design to adapt to small devices.

[0005] However, the optical fibers in optoelectronic composite cables for intelligent communication are easily affected by external forces. For example, when the optoelectronic composite cable is in a micro-bent state, the pipe covering the optical fiber deforms, which will cause the optical fiber to be laterally pressed under the action of the bending external force, resulting in light loss; and usually when the pipe covering the optical fiber has good anti-lateral pressure performance, the pipe covering the optical fiber has poor impact resistance and is prone to rupture under external force impact, resulting in a decline in the protection performance of the optical fiber and a decline in the quality and stability of communication; and the optical fibers in optoelectronic composite cables for intelligent communication are easily affected by electromagnetic interference, thereby affecting the quality and stability of communication. Summary of the Invention

[0006] In order to solve the problem that the pipes covering the optical fibers in existing optoelectronic composite cables cannot simultaneously have high anti-lateral pressure, anti-impact performance, and shielding performance, this application provides an electromagnetic shielding material, its preparation process, and an optoelectronic composite cable.

[0007] In the first aspect, this application provides an electromagnetic shielding material:

[0008] An electromagnetic shielding material, by weight, comprises 25-35 parts of styrene-butadiene rubber, 10-15 parts of silicone rubber, 20-35 parts of metallocene polyolefin, 10-20 parts of carbon-based conductive filler, 0.5-1.5 parts of vulcanizing agent and 0.5-1.5 parts of vulcanization accelerator;

[0009] The carbon-based conductive filler is graphene and / or carbon nanotubes.

[0010] By adopting the above technical solution, the compatibility of styrene-butadiene rubber and silicone rubber can improve the toughness of the electromagnetic shielding material; the compatibility of metallocene polyolefin, carbon-based conductive filler with styrene-butadiene rubber and silicone rubber can not only improve the modulus, strength and heat insulation performance, but also form a conductive network in the electromagnetic shielding material, thereby improving its electromagnetic shielding performance; the compatibility of metallocene polyolefin, graphene and carbon nanotubes with styrene-butadiene rubber and silicone rubber makes the prepared electromagnetic shielding material have good anti-side pressure, bending strength, impact strength and shielding effectiveness at the same time.

[0011] Preferably, the carbon-based conductive filler is a composition of graphene and carbon nanotubes with a mass ratio of 1:(1-8).

[0012] By adopting the above technical solution, the carbon-based conductive filler has better dispersion performance and can better form a conductive network, thereby improving the anti-side pressure, bending strength, impact strength and shielding effectiveness of the electromagnetic shielding material.

[0013] Preferably, the carbon-based conductive filler is treated with a surface treatment solution for 24-30 h; the surface treatment solution comprises 2-4 g / L of dopamine and the balance of water.

[0014] By adopting the above technical solution, the carbon-based conductive filler is treated with the surface treatment solution to form a polydopamine film layer on the surface of the carbon-based conductive filler, which can reduce the agglomeration of the carbon-based conductive filler and improve its dispersion performance and compatibility in the electromagnetic shielding material, thereby improving the anti-side pressure, bending strength, impact strength and shielding effectiveness of the electromagnetic shielding material.

[0015] Preferably, the surface treatment solution further comprises 0.5-3 g / L of silane coupling agent.

[0016] Preferably, the pH value of the surface treatment solution is 7-9, the silane coupling agent is vinyl silane coupling agent; the silicone rubber is silicone rubber containing vinyl.

[0017] By adopting the above technical solution, a silane coupling agent is used in the surface treatment liquid to further improve the dispersibility of the carbon-based conductive filler and its compatibility with styrene-butadiene rubber and silicone rubber; preferably, the silane coupling agent is a vinyl silane coupling agent, and the vinyl group in the vinyl silane coupling agent can participate in the vulcanization reaction with the vinyl group in the vinyl silicone rubber, so that a network structure is formed among the styrene-butadiene rubber, silicone rubber and carbon-based conductive filler in the prepared electromagnetic shielding material, producing a better synergistic effect, thereby improving the strength and toughness of the prepared electromagnetic shielding material.

[0018] Preferably, after the carbon-based conductive filler is treated with the surface treatment liquid, it is then treated with a copper plating solution with a pH value of 6 - 8 for 1 - 4 h. The copper plating solution includes 40 - 60 mmol / L of copper chloride, 40 - 60 mmol / L of EDTA·2Na, 0.1 - 0.3 mol / L of boric acid, and 0.1 - 0.3 mol / L of dimethylamine borane.

[0019] By adopting the above technical solution, after the carbon-based conductive filler is treated with the surface treatment liquid, it is then treated with a copper plating solution. The o-dihydroxybenzene groups and amino groups present on the polydopamine film layer can adsorb copper ions in the solution, and the copper ions can be reduced to nano-copper particles under the action of the reducing agent dimethylamine borane and deposited on the surface of the polydopamine, further improving the electrical conductivity and shielding performance of the carbon-based conductive filler and the electromagnetic shielding material.

[0020] Preferably, the electromagnetic shielding material further includes 0.5 - 2 parts by weight of zinc oxide and 0.25 - 0.75 parts by weight of antioxidant.

[0021] By adopting the above technical solution, the thermal stability and aging resistance of the electromagnetic shielding material can be improved, and zinc oxide can promote vulcanization.

[0022] In a second aspect, the present application provides a preparation process for an electromagnetic shielding material:

[0023] A preparation process for an electromagnetic shielding material, and its preparation process is as follows:

[0024] Plasticizing: Plasticize silicone rubber, styrene-butadiene rubber, and metallocene polyolefin evenly at a temperature of 140 - 160 °C respectively to obtain plasticized rubber.

[0025] Mixing: Mix the accelerator and vulcanizing agent with the plasticized rubber and mix at a temperature of 55 - 60 °C to become mixed rubber.

[0026] Extrusion molding and vulcanization: The mixed rubber is extruded into the required shape and size, and then vulcanized to obtain the electromagnetic shielding material; the vulcanization temperature is 160 - 180 °C.

[0027] Preferably, the zinc oxide and antioxidant are mixed with the plasticized rubber in the mixing step.

[0028] By adopting the above technical solution, an electromagnetic shielding material with good lateral pressure resistance, bending strength, impact strength and shielding effectiveness is prepared.

[0029] In a third aspect, the present application provides an optical and electrical composite cable:

[0030] An optical and electrical composite cable sequentially includes, from the inside to the outside: an optical fiber, an inner cylinder, an electric wire and an outer cylinder; the inner cylinder is wrapped around the outside of the optical fiber, and the inner cylinder is prepared from the electromagnetic shielding material according to any one of claims 1-9; a plurality of the electric wires are arranged outside the inner cylinder; the outer cylinder is wrapped around the outside of the plurality of electric wires, and the plurality of electric wires are located between the inner cylinder and the outer cylinder; the outer cylinder sequentially includes, from the inside to the outside, a winding tape for bundling the electric wires, a conductive shielding layer and a resin outer sleeve.

[0031] Preferably, the winding tape is in contact with the outer surface of the electric wire and is spiral, and the material can be a paper tape, a tape made of polytetrafluoroethylene (PTFE) or a polyester tape; the conductive shielding layer can be one of an aluminum foil shielding layer, a copper mesh shielding layer and a tinned copper mesh shielding layer; the material of the resin outer sleeve can be a resin such as polyethylene (PE) or polyvinyl chloride (PVC).

[0032] Preferably, the optical fiber includes, from the inside to the outside, a core and a cladding; the electric wire is composed of an insulator and a conductor.

[0033] By adopting the above technical solution, in the optical and electrical composite cable, an inner cylinder prepared from the electromagnetic shielding material in the present application is arranged between the optical fiber and the electric wire. The inner cylinder has good electrical conductivity and electromagnetic shielding performance, can reduce the electromagnetic interference to the optical fiber, and further improve the quality and stability of communication; the inner cylinder has good lateral pressure resistance, bending strength and impact strength, and further reduces the pressure of the inner cylinder on the optical fiber under the action of external force, and further improves the quality and stability of communication.

[0034] In summary, the present application has the following beneficial effects:

[0035] 1. An electromagnetic shielding material, in parts by weight, 25-35 parts of styrene-butadiene rubber, 10-15 parts of silicone rubber, 20-35 parts of metallocene polyolefin, 10-20 parts of carbon-based conductive filler, 0.5-1.5 parts of vulcanizing agent and 0.5-1.5 parts of vulcanization accelerator; the carbon-based conductive filler is graphene and / or carbon nanotube; by using metallocene polyolefin, carbon-based conductive filler, styrene-butadiene rubber and silicone rubber in combination, the prepared electromagnetic shielding material has good lateral pressure resistance, bending strength, impact strength and shielding effectiveness at the same time, reduces the electromagnetic interference to the optical fiber and reduces the lateral pressure on the optical fiber under the condition of micro-bending of the optical and electrical composite cable, and further improves the quality and stability of communication of the optical and electrical composite cable.

[0036] 2. Further, the carbon-based conductive filler is treated with a surface treatment liquid; the surface treatment liquid includes 2-4 g / L dopamine, 0.5-3 g / L silane coupling agent and the balance water. After the carbon-based conductive filler is treated with the surface treatment liquid, a polydopamine film layer is formed on the surface performance of the carbon-based conductive filler, which can reduce the agglomeration of the carbon-based conductive filler and improve the dispersion performance and compatibility performance in the electromagnetic shielding material, thereby improving the strength, conductivity and electromagnetic shielding performance of the electromagnetic shielding material.

[0037] 3. Further, after the carbon-based conductive filler is treated with the surface treatment liquid, it is then treated with a copper plating solution. The polydopamine layer adsorbs copper ions in the copper plating solution, and the copper ions can be reduced to nano-copper particles under the action of the reducing agent dimethylamine borane and deposited on the surface of the polydopamine, further improving the conductivity and shielding performance of the electromagnetic shielding material. Specific embodiments

[0038] Raw materials

[0039] Carbon nanotubes (content 95%, multi-walled diameter 15 nm, multi-walled length 30 μm), graphene (grayish-black powder, content 75%, sheet size 8 μm), sulfur (industrial grade, content: 99.9%), metallocene polyethylene (using MVLDPE, melting point: 126 °C, injection molding grade), metallocene polypropylene (melting point: 164 °C, injection molding grade).

[0040] Preparation examples of intermediates

[0041] Preparation example 1, a carbon-based conductive filler, using the raw materials as shown in Table 1, and its preparation process is as follows:

[0042] Treatment with the surface treatment liquid: The carbon-based conductive filler is treated with the surface treatment liquid (the solvent is water, and the pH value is adjusted with Tris-HCL buffer solution, and the mass ratio of the carbon-based conductive filler to the surface treatment liquid is 1:15) for 28 h, then centrifuged and filtered, washed with deionized water, and then placed in a vacuum oven at 50 °C for drying for 8 h (in other embodiments, the drying temperature can be any temperature in the range of 40-60 °C, and the drying time can be any time in the range of 7-12 h), and reserved.

[0043] Treatment with the copper plating solution: After the carbon-based conductive filler is treated with the surface treatment liquid, it is then treated with a copper plating solution with a pH value of 7 (the solvent is water, and the pH value of the copper plating solution is adjusted with 1 mol / L NaOH solution) for 3 h, the temperature of the copper plating solution is 45 °C, the mass ratio of the carbon-based conductive filler after the surface treatment liquid treatment to the copper plating solution is 1:25, after filtration, the reacted carbon-based conductive filler is washed with deionized water and ethanol, and dried in a vacuum oven at 40 °C for 2 h (in other embodiments, the drying temperature can be any temperature in the range of 40-60 °C, and the drying time can be any time in the range of 1-4 h).

[0044] Preparation Example 2 to Preparation Example 3: A carbon-based conductive filler, which is different from Preparation Example 1 in that the types of raw materials, the weights of raw materials, and the settings of preparation process parameters used in the preparation method are different, as shown in Table 1 specifically.

[0045] Table 1: List of the types of raw materials, the weights of raw materials, and the settings of preparation process parameters used in the preparation methods of the carbon-based conductive fillers in Preparation Example 1 to Preparation Example 3

[0046]

[0047]

[0048] Preparation Example 4: A carbon-based conductive filler, which is different from Preparation Example 1 in that vinyltriethylsilane coupling agent is used to replace vinyltrimethylsilane coupling agent in equal amounts.

[0049] Preparation Example 5: A carbon-based conductive filler, which is different from Preparation Example 1 in that γ-(2,3-epoxypropoxy)propyltrimethoxysilane is used to replace vinyltrimethylsilane coupling agent in equal amounts.

[0050] Preparation Example 6: A carbon-based conductive filler, which is different from Preparation Example 1 in that 3-aminopropyltrimethoxysilane is used to replace vinyltrimethylsilane coupling agent in equal amounts.

[0051] Preparation Example 7: A carbon-based conductive filler, which is different from Preparation Example 1 in that vinyltrimethylsilane coupling agent is not used.

[0052] Preparation Example 8: A carbon-based conductive filler, which is different from Preparation Example 1 in that the carbon-based conductive filler uses a composition of graphene and carbon nanotubes with a mass ratio of 1:1.

[0053] Preparation Example 9: A carbon-based conductive filler, which is different from Preparation Example 1 in that the carbon-based conductive filler uses a composition of graphene and carbon nanotubes with a mass ratio of 1:3.

[0054] Preparation Example 10: A carbon-based conductive filler, which is different from Preparation Example 1 in that the carbon-based conductive filler uses a composition of graphene and carbon nanotubes with a mass ratio of 1:4.

[0055] Preparation Example 11: A carbon-based conductive filler, which is different from Preparation Example 1 in that the carbon-based conductive filler uses a composition of graphene and carbon nanotubes with a mass ratio of 1:6.

[0056] Preparation Example 12: A carbon-based conductive filler, which is different from Preparation Example 1 in that the carbon-based conductive filler uses a composition of graphene and carbon nanotubes with a mass ratio of 1:8.

[0057] Preparation Example 13, a carbon-based conductive filler, which is different from Preparation Example 1 in that the carbon-based conductive filler is graphene.

[0058] Preparation Example 14, a carbon-based conductive filler, which is different from Preparation Example 1 in that the carbon-based conductive filler is not treated with copper plating solution.

[0059] Preparation Example 15, a carbon-based conductive filler, which is different from Preparation Example 1 in that the carbon-based conductive filler is not treated with surface treatment solution and copper plating solution.

[0060] Examples

[0061] Example 1-1, an electromagnetic shielding material, using the raw materials as shown in Table 2, and its preparation process includes the following steps: Plasticizing: Respectively put silicone rubber (using methyl vinyl silicone rubber, average molecular weight 800,000), styrene-butadiene rubber (styrene content 35%, melting point 85°C, density 1.2 g / cm3), and metallocene polyolefin into the internal mixer, and plasticize at a temperature of 140°C for 10 minutes to obtain plasticized rubber.

[0062] Mixing: After adding the plasticized rubber to the open mill, after mixing for 5 minutes (the purpose is to make the rubber compound softer and better fuse with zinc oxide, anti-aging agent, accelerator and vulcanizing agent, and any time in the range of 3-8 minutes can be selected), add the accelerator, vulcanizing agent, zinc oxide and anti-aging agent, and mix at a temperature of 60°C for 20 minutes to become a mixed rubber.

[0063] Extrusion molding and vulcanization: The mixed rubber is extruded through an extruder (extrusion temperature 150±10°C), and after extrusion, a pipe with a thickness of 0.3 mm is formed, and then the rubber pipe is loaded into a vulcanizer and prepared into an electromagnetic shielding material through vulcanization; the vulcanization temperature is 170°C, the vulcanization pressure is 1.2 MPa, and the vulcanization time is 8 minutes (in other examples, the vulcanization pressure can be any pressure value in the range of 1-1.3 MPa; the vulcanization time is any vulcanization time in the range of 5-12 minutes).

[0064] Examples 1-2 to 1-3, an electromagnetic shielding material, which is different from Example 1-1 in that the types of raw materials, the weights of raw materials and the settings of preparation process parameters used in its preparation process are different, as shown in Table 2 specifically.

[0065] Table 2: List of the types of raw materials, the weights of raw materials and the settings of preparation process parameters used in the preparation process of the electromagnetic shielding materials in Examples 1-1 to 1-3

[0066]

[0067]

[0068] Examples 1-4 to 1-15, an electromagnetic shielding material, which is different from Example 1-1 in that the carbon-based conductive filler is successively the carbon-based conductive fillers of Preparation Examples 4 to 15.

[0069] Example 1-16, an electromagnetic shielding material, which is different from Example 1-15 in that zinc oxide and antioxidant are not used.

[0070] Example 2-1, an optical and electrical composite cable, the structure of which is as follows:

[0071] An optical and electrical composite cable successively includes from inside to outside: an optical fiber, an inner cylinder, an electric wire, and an outer cylinder; the inner cylinder is wrapped around the outside of the optical fiber (22 optical fibers are used), and the total cross-sectional area of the optical fibers accounts for 70% of the inner cylinder (8 optical fibers are used in this example, and in other examples, the total cross-sectional area of the optical fibers can account for 68-80% of the inner cylinder); the inner cylinder is prepared from the electromagnetic shielding material of Example 1-1; multiple electric wires (24 electric wires are used) are arranged outside the inner cylinder; the outer cylinder is wrapped around the outside of the multiple electric wires, and the electric wires are wound into a spiral shape along the outer peripheral surface of the inner cylinder and are located between the inner cylinder and the outer cylinder; the outer cylinder successively includes from inside to outside a winding tape (made of polytetrafluoroethylene) for bundling the electric wires, a conductive shielding layer (made of a copper mesh shielding layer), and a resin outer sleeve (made of polyethylene).

[0072] Examples 2-2 to 2-16, an optical and electrical composite cable, which is different from the optical and electrical composite cable of Example 2-1 in that the inner cylinder is successively prepared from the electromagnetic shielding materials of Examples 1-2 to 1-16.

[0073] Comparative Example

[0074] Comparative Example 1-1, an electromagnetic shielding material, which is different from Example 1-16 in that styrene-butadiene rubber is used to replace silicone rubber in equal amounts.

[0075] Comparative Example 1-2, an electromagnetic shielding material, which is different from Example 1-16 in that styrene-butadiene rubber is used to replace metallocene polyolefin in equal amounts.

[0076] Comparative Example 1-3, an electromagnetic shielding material, which is different from Example 1-16 in that styrene-butadiene rubber is used to replace metallocene polyolefin and silicone rubber in equal amounts.

[0077] Comparative Example 1-4, an electromagnetic shielding material, which is different from Example 1-16 in that polyethylene (LDPE, melting point: 126°C, injection molding grade) is used to replace metallocene polyolefin in equal amounts.

[0078] Comparative Example 1-5, an electromagnetic shielding material, which is different from Example 1-16 in that the carbon-based conductive filler is not used.

[0079] Comparative Examples 2-1 to 2-5: An optical and electrical composite cable, which is different from the optical and electrical composite cable of Example 2-1 in that the inner cylinder is sequentially prepared from the electromagnetic shielding materials of Comparative Examples 1-1 to 1-5.

[0080] Performance Detection Test

[0081] Test 1: Lateral Pressure Resistance

[0082] The lateral pressure resistance performance of the electromagnetic shielding materials of Examples 1-1 to 1-16, Comparative Example 1-1 and Comparative Examples 1-5 was detected by the test method of GB / T 20186.1-2006, and the test results are shown in Table 3.

[0083] The lateral pressure resistance performance refers to the pressure value applied to the sleeve when the inner diameter strain of the sleeve reaches 50% during the lateral pressure application process.

[0084] Test 2: Bending Strength

[0085] The bending strength of the electromagnetic shielding materials of Examples 1-1 to 1-16, Comparative Example 1-1 and Comparative Examples 1-5 was detected by the test method of ASTM D790, and the test results are shown in Table 3.

[0086] Test 3: Room Temperature Notchless Impact Performance

[0087] The impact strength of the electromagnetic shielding materials of Examples 1-1 to 1-16, Comparative Example 1-1 and Comparative Examples 1-5 was detected by the impact performance test: the test method of ASTM D4812, and the test results are shown in Table 3.

[0088] Test 4: Shielding Effectiveness

[0089] The shielding effectiveness of the electromagnetic shielding materials of Examples 1-1 to 1-16, Comparative Example 1-1 and Comparative Examples 1-5 was detected by the test method of GB / T 32511-2016, and the test results are shown in Table 3.

[0090] Table 3: Evaluation Results List of Lateral Pressure Resistance, Bending Strength, Impact Strength and Shielding Effectiveness of Electromagnetic Shielding Materials of Examples 1-1 to 1-16, Comparative Example 1-1 and Comparative Examples 1-5

[0091]

[0092]

[0093] Combined with Examples 1-1 to 1-16, Comparative Example 1-1 and Comparative Examples 1-5 and combined with Table 3, it can be seen that:

[0094] The electromagnetic shielding materials of Comparative Examples 1-1 and 1-5 and Examples 1-16 simultaneously have good lateral pressure resistance, bending strength, impact strength and shielding effectiveness; perhaps because metallocene polyolefins can improve the electrical conductivity and shielding effectiveness of electromagnetic shielding materials, and can promote the electrical conductivity and shielding effectiveness of carbon-based conductive fillers; the use of silicone rubber in the electromagnetic shielding material improves the impact resistance of the electromagnetic shielding material, and at the same time improves the synergistic effect between the carbon-based conductive filler, styrene-butadiene rubber and metallocene polyolefin, so that the carbon-based conductive filler better exerts the strengthening and toughening effects in the electromagnetic shielding material; the use of metallocene polyolefin, carbon-based conductive filler, styrene-butadiene rubber and silicone rubber in the electromagnetic shielding material makes the prepared electromagnetic shielding material simultaneously have good lateral pressure resistance, bending strength, impact strength and shielding effectiveness.

[0095] The lateral pressure resistance, bending strength and impact strength of the electromagnetic shielding materials of Examples 1-1 and 1-4 are higher than those of Examples 1-5 to 1-7, indicating that the carbon-based conductive filler treated with a surface treatment solution containing a silane coupling agent, and preferably the silane coupling agent is a vinyl silane coupling agent, improves the lateral pressure resistance, bending strength and impact strength of the electromagnetic shielding material; perhaps because the silane coupling agent promotes the dispersion of the carbon-based conductive filler, and preferably the silane coupling agent is a vinyl silane coupling agent, and the vinyl group in the vinyl silane coupling agent can participate in the vulcanization reaction together with styrene, improving the synergistic performance between the carbon-based conductive filler and other components of the electromagnetic shielding material, and thus improving the lateral pressure resistance, bending strength and impact strength of the electromagnetic shielding material.

[0096] The lateral pressure resistance, bending strength, impact strength and shielding effectiveness of the electromagnetic shielding materials of Examples 1-9 to 1-11 are higher than those of Examples 1-8, 1-12 and 1-13, indicating that graphene and carbon nanotubes are preferably used in combination in the carbon-based conductive filler, and preferably their dosages are selected, which improves the lateral pressure resistance, bending strength, impact strength and shielding effectiveness of the electromagnetic shielding material; perhaps because the combination of graphene and carbon nanotubes, and preferably their dosages, makes the carbon-based conductive filler have good dispersion performance and reinforcement performance, and the carbon-based conductive filler can better form a conductive network, thereby improving the lateral pressure resistance, bending strength, impact strength and electromagnetic shielding performance of the electromagnetic shielding material.

[0097] Compared with Examples 1-14 and 1-15, the electromagnetic shielding material of Example 1-1 has higher lateral pressure resistance, bending strength, impact strength and shielding effectiveness, indicating that the electromagnetic shielding material treated with the surface treatment liquid and the copper plating liquid has higher lateral pressure resistance, bending strength, impact strength and shielding effectiveness. It may be because after the carbon-based conductive filler is treated with the surface treatment liquid, a polydopamine film layer is formed on the surface of the carbon-based conductive filler, improving the dispersion performance of the carbon-based conductive filler and the compatibility with other components in the electromagnetic shielding material. The carbon-based conductive filler in the electromagnetic shielding material can better form a conductive network, thereby improving the lateral pressure resistance, bending strength, impact strength and shielding effectiveness of the electromagnetic shielding material; after the carbon-based conductive filler is treated with the surface treatment liquid and then with the copper plating liquid, the polydopamine layer adsorbs copper ions in the copper plating liquid, and the copper ions are reduced to nano-copper particles under the action of the reducing agent dimethylamine borane and deposited on the surface of the polydopamine, further improving the electrical conductivity and shielding performance of the carbon-based conductive filler.

[0098] The mechanical properties, optical properties and electrical properties of the optical and electrical composite cables of Examples 2-1 to 2-16 and the optical and electrical composite cables of Comparative Examples 2-1 to 2-5 were tested with reference to IEC62807-3:2023; and the weight of a one-meter-long optical and electrical composite cable was weighed.

[0099] The working tensile load of the optical and electrical composite cables of Examples 2-1 to 2-16 is in the range of 15.4 - 16 kN, and the breaking tensile load is in the range of 12.5 - 13.5 kN, and the optical and electrical properties are qualified.

[0100] The working tensile load of the optical and electrical composite cables of Comparative Examples 2-1 to 2-5 is in the range of 14 - 14.5 kN, and the breaking tensile load is in the range of 11.4 - 12.1 kN, and the optical and electrical properties are qualified.

[0101] This specific embodiment is only an explanation of the present application and does not limit the present application. Those skilled in the art can make modifications without creative contributions to this embodiment after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. An electromagnetic shielding material, characterized in that, It is composed of 25 - 35 parts by weight of styrene - butadiene rubber, 10 - 15 parts of silicone rubber, 20 - 35 parts of metallocene polyolefin, 10 - 20 parts of carbon - based conductive filler, 0.5 - 1.5 parts of vulcanizing agent, 0.5 - 1.5 parts of vulcanization accelerator, 0.5 - 2 parts by weight of zinc oxide and 0.25 - 0.75 parts by weight of antioxidant; the silicone rubber is a silicone rubber containing vinyl; The carbon - based conductive filler is a composition of graphene and carbon nanotubes with a mass ratio of 1:(1 - 8); The carbon - based conductive filler is treated with a surface treatment liquid for 24 - 30 h; the surface treatment liquid includes 2 - 4 g / L of dopamine, 0.5 - 3 g / L of silane coupling agent and the balance of water; The pH value of the surface treatment liquid is 7 - 9, and the silane coupling agent is a vinyl silane coupling agent; After the carbon - based conductive filler is treated with the surface treatment liquid, it is then treated with a copper - plating liquid with a pH value of 6 - 8 for 1 - 4 h. The copper - plating liquid includes 40 - 60 mmol / L of copper chloride, 40 - 60 mmol / L of EDTA·2Na, 0.1 - 0.3 mol / L of boric acid, and 0.1 - 0.3 mol / L of dimethylamine borane.

2. A preparation process of the electromagnetic shielding material according to claim 1, characterized in that, It includes the following steps: Plasticizing: Plasticize silicone rubber, styrene - butadiene rubber, and metallocene polyolefin evenly at a temperature of 140 - 160 °C respectively to prepare plasticized rubber; Mixing: Mix the accelerator and vulcanizing agent with the plasticized rubber and mix at a temperature of 55 - 60 °C to form mixed rubber; Extrusion molding and vulcanization: The mixed rubber is extruded into the required shape and size, and then vulcanized to prepare an electromagnetic shielding material; the vulcanization temperature is 160 - 180 °C.

3. The preparation process of the electromagnetic shielding material according to claim 2, characterized in that, The zinc oxide and antioxidant are mixed with the plasticized rubber in the mixing step.

4. An optical and electrical composite cable, characterized in that, From the inside to the outside, it successively includes: optical fiber, inner cylinder, electric wire, and outer cylinder; the inner cylinder is wrapped around the outside of the optical fiber, and the inner cylinder is prepared from the electromagnetic shielding material according to any one of claims 1 - 3; multiple electric wires are arranged outside the inner cylinder; the outer cylinder is wrapped around the outside of the multiple electric wires, and the multiple electric wires are located between the inner cylinder and the outer cylinder; the outer cylinder successively includes a winding tape for bundling the electric wires, a conductive shielding layer, and a resin outer sleeve from the inside to the outside.

Images