Graphene-improved antistatic cable shielding layer material and mining cable

Abstract

The invention discloses a graphene-improved antistatic cable shielding layer material and a mining cable. The graphene-improved antistatic cable shielding layer material is prepared from the following components in parts by mass: 60 to 75 parts of hydrogenated butadiene-acrylonitrile rubber matrix, 3 to 5 parts of vertical orientation modified graphene, 8 to 12 parts of dual-ionic liquid and 1 to 2 parts of cross-linking agent, the orientation degree of the vertical orientation modified graphene is greater than 60%; the dual-ionic liquid is a compound of 1-ethyl-3-methylimidazole bis (trifluoromethanesulfonyl) imide salt and trihexyltetradecyl phosphine bis (trifluoromethanesulfonyl) imide salt. The shielding layer material disclosed by the invention has long-term stable high shielding performance and antistatic safety.

Description

Technical Field

[0001] The present application relates to mining cables, and in particular to a graphene-modified antistatic cable shielding layer material and a mining cable. Background Art

[0002] In recent years, with the continuous development of industry, the application of mining cables has become increasingly widespread. In complex working environments such as mines, cables must not only ensure stable power transmission, but also have excellent shielding and anti-static properties to prevent external electromagnetic interference from affecting cable signals, while also avoiding safety hazards caused by static electricity accumulation.

[0003] To solve the cable shielding and antistatic problems, the following methods are commonly used. One is to add ordinary carbon fillers, such as carbon black, to the cable shielding layer material, and use the conductive properties of the carbon fillers to achieve a certain degree of electromagnetic shielding and antistatic effect. Another common method is to use traditional dilute antistatic agents. This type of antistatic agent absorbs moisture from the environment and forms a conductive channel on the surface of the material, thereby dissipating static charge. In addition, some solutions will use the method of adding metal powder or fiber to the rubber matrix, relying on the good conductivity of the metal to improve the shielding performance and antistatic properties of the shielding layer. These methods can improve the performance of the cable shielding layer to a certain extent, but they also expose some shortcomings in actual applications.

[0004] However, these conventional methods in the prior art have obvious defects. Ordinary carbon-based fillers are easy to agglomerate in the rubber matrix, making it difficult to form a uniform conductive network, resulting in poor shielding effect. Moreover, as the use time increases, the performance of the carbon-based fillers tends to decline, and long-term stable shielding performance cannot be guaranteed. The conductivity of traditional dilute antistatic agents depends on the ambient humidity. The antistatic effect will be greatly reduced in a dry environment and cannot meet the use requirements in complex environments. The addition of metal powder or fiber will significantly increase the weight and cost of the cable shielding layer, and may also affect the processing performance and flexibility of the material, which is not conducive to the installation and use of the cable. Summary of the Invention

[0005] In order to improve the antistatic performance of lightweight cable shielding materials, a graphene-modified antistatic cable shielding material and a mining cable are provided.

[0006] The first object of the present invention is achieved by the following technical solutions: A graphene-modified antistatic cable shielding layer material comprises the following components in parts by weight: 60-75 parts of hydrogenated nitrile rubber matrix, 3-5 parts of vertically oriented modified graphene, 8-12 parts of diionic liquid, 1-2 parts of cross-linking agent; The orientation degree of the vertically oriented modified graphene is greater than 60%; The diionic liquid is a compound of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and trihexyltetradecylphosphine bis(trifluoromethanesulfonyl)imide salt.

[0007] By adopting the above technical solution, electromagnetic waves can be reflected and absorbed between graphene sheets. In the vertically oriented modified graphene in this application, the graphene sheets are arranged vertically along the thickness direction and the interlayer spacing is uniform. Electromagnetic waves can be reflected and absorbed multiple times between the vertically oriented modified graphene sheets, and the shielding performance of the vertically oriented modified graphene is better. At the same time, the ordered and uniformly arranged graphene sheets will form a highly ordered conductive channel, shortening the electron migration path along the longitudinal path and lowering the barrier to hopping conduction along the longitudinal path, thereby reducing the longitudinal resistivity and percolation threshold of the vertically oriented modified graphene. The reduction in longitudinal resistivity will increase the electromagnetic reflectivity of the graphene, and the reduction in the percolation threshold can enable the vertically oriented modified graphene to form a penetrating conductive network in the shielding layer material with a small amount of addition, thereby improving the shielding effect of the shielding layer material and reducing the cost of graphene usage; Different from traditional dilute antistatic agents, the conductivity of diionic liquids depends on the intrinsic ion concentration and non-environmental humidity. The cations in the ionic liquids (such as [EMIM] + ) and anions (such as [TFSI]-) dissociate in the rubber matrix to form mobile charge carriers. After mixing, the ionic liquid molecules combine with the hydrogenated nitrile rubber segments through polar interactions, forming ion channels that penetrate the matrix, achieving rapid migration and dissipation of static charges; In addition, the electronic conductive network of the vertically oriented modified graphene is closely related to the ion migration path of the diionic liquid (cation [EMIM] + Bulk phase migration and anion [P66614]-surface adsorption) form dual conductive paths, covering the full frequency band charge regulation; The oxygen-containing groups (-COOH, -OH) on the graphene surface form hydrogen bonds with the imidazole ring / phosphine group of the ionic liquid. The hydrogen bonding inhibits graphene agglomeration and improves the dispersion stability of the ionic liquid in the matrix. As a result, the shielding layer material of the present application has long-term stable high shielding performance and antistatic safety.

[0008] Optionally, the method for adjusting the vertical orientation of the modified graphene is as follows: Graphene oxide and polystyrene microspheres are dispersed in THF, and after the polystyrene microspheres swell, they are cast into a film, and then calcined in an inert atmosphere to remove the polystyrene to obtain vertically oriented modified graphene.

[0009] By adopting the above technical solution, polystyrene microspheres swell in THF to form a hexagonal close-packed structure, and graphene is driven by capillary force to fill the gaps between the microspheres. After calcination to remove polystyrene, vertical channels are formed with good orientation, which can further reduce the percolation threshold of the conductive network and improve the shielding effect.

[0010] Optionally, it comprises 0.3 to 0.5 parts of silver nanowires, wherein the diameter of the silver nanowires is 30±5 nm and the aspect ratio is 1200 to 1500.

[0011] Optionally, the aspect ratio of the silver nanowires is 1400.

[0012] By adopting the above technical solution, high aspect ratio silver nanowires fill the gaps in graphene sheets through a "wire-surface" interpenetrating structure to form a three-dimensional conductive network, which can improve high-frequency shielding performance and reduce the defect rate of the conductive network while slightly increasing the material density.

[0013] Optionally, the silver nanowires are surface-modified with polydopamine.

[0014] By adopting the above technical solution, polydopamine forms a film layer on the surface of the silver nanowires, and enhances the interface bonding through Ag-O bonds and π-π conjugation, thereby improving the oxidation resistance and dispersion stability of the silver nanowires.

[0015] Optionally, the cross-linking agent is a dynamic cross-linking agent containing a disulfide bond.

[0016] By adopting the above technical solution, the disulfide bonds can be reversibly broken and reorganized under thermal activation at 80-160°C, giving the material self-repair ability, thereby improving the bending life of the shielding layer and stabilizing the cross-linking density after vulcanization, thereby improving the performance stability of the cable shielding layer material after production and secondary processing.

[0017] Optionally, the cross-linking agent is tetrathiodiethyl diisocyanate.

[0018] By adopting the above technical solution, the isocyanate group (-NCO) of tetrathiodiethyl diacetate reacts with the cyanide group (-CN) of hydrogenated nitrile butadiene rubber to form a covalent urea bond (-NHCONH-). At the same time, the sulfur atom forms a SO bond with the hydroxyl group on the edge of graphene, further improving the interfacial bonding strength of the material.

[0019] The first object of the present invention is achieved by the following technical solutions: A mining cable comprises a battery core, an insulating layer, a shielding layer, and a sheath layer. The shielding layer is obtained from the above-mentioned graphene-modified antistatic cable shielding layer material.

[0020] By adopting the above technical solutions, the shielding layer material combines lightweight, high shielding efficiency and anti-static safety, making the mining cable safe, reliable and durable in flammable and explosive environments.

[0021] In summary, this application has at least the following beneficial effects: 1. Using vertically oriented graphene to form an ordered conductive channel, combined with the intrinsic ionic conductivity of the diionic liquid, it achieves full-band electromagnetic shielding and rapid dissipation of static charges; 2. Silver nanowires are used to fill the gaps between the layers, forming a three-dimensional conductive network, which improves high-frequency shielding without significantly increasing weight; 3. The cable shielding layer material of the present application has both antistatic properties and high shielding effectiveness, and is suitable for flammable and explosive environments. DETAILED DESCRIPTION

[0022] raw material Ethylene glycol, ethanol, tetrahydrofuran, and silver nitrate were commercially available products of analytical grade purity.

[0023] Graphene oxide, single layer or double layer structure mixed doping, its thickness is 0.8 to 1.2 nanometers, the sheet size is 4 to 5 μm, and the oxidation degree GO=2.3.

[0024] Polystyrene microspheres, S-PS200, a product of Suzhou Zhiwei Nanotechnology Co., Ltd., with a particle size of 200 nm.

[0025] PVP K30 is a product of BASF, with a K value of 27.0-33.0 (1% aqueous solution), a solid content of 95-100%, a pH value of 3.0-7.0 (10% aqueous solution), and a residual monohydrate content of ≤0.01%.

[0026] Dopamine hydrochloride, Cas No. 62-31-7, purity greater than 98%, melting point 241-243°C.

[0027] Tris buffer was purchased from Beijing Biolab Technology Co., Ltd.

[0028] The hydrogenated nitrile rubber matrix is commercially available with the brand name HNB5360, an acrylonitrile content of 38 wt % and a density of 0.98 g / cm 3 .

[0029] 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, Cas number 174899-2-2, purity 99.5%, obtained from Pushan Industrial.

[0030] Trihexyltetradecylphosphine bis(trifluoromethanesulfonyl)imide salt, Cas No. 460092-03-9, purity 98%, was obtained from Zhengzhou Jacks.

[0031] Tetrathiodiethyl diisocyanate, Cas number 63224-35-1, purity 97.2wt% Dicumyl peroxide, Cas number 80-43-3, active oxygen content 5.92%.

[0032] Zinc diethyldithiocarbamate, CAS number: 14324-55-1, purity: 99wt%.

[0033] Preparation Example 1 A vertically oriented modified graphene, the preparation method of which is as follows: mixing graphene oxide and polystyrene microspheres in a mass ratio of 1:5 to obtain a mixture; The mixture was added to 20 times the mass of tetrahydrofuran, and the mixture was stirred until the swelling ratio of the polystyrene microspheres reached 1:3.2 to obtain a casting material; The cast material was tape-cast into a film with a thickness of 40 μm and vacuum-dried at 40°C for 12 h. Then, under nitrogen protection, the temperature was raised to 500°C at 5°C / min and calcined for 2h to remove polystyrene. Then, the volume content of the ambient atmosphere was adjusted to N2 / H2=96:4, the temperature was raised to 800°C at 5°C / min and calcined for 40min, and then air flow pulverization was performed to obtain vertically oriented modified graphene.

[0034] The detection shows that the orientation rate of the vertically oriented modified graphene is 68.5%, which is greater than 60%.

[0035] Preparation Example 2 A modified graphene, the preparation method of which is as follows: The graphene oxide was heated to 500°C at 5°C / min and calcined for 2h under nitrogen protection, and then the ambient atmosphere volume content was adjusted to N2 / H2=96:4, and the temperature was heated to 800°C at 5°C / min and calcined for 40min to obtain reduced graphene oxide.

[0036] The orientation rate of reduced graphene oxide was detected to be 19.2%, which is less than 60%.

[0037] Preparation Example 3 A vertically oriented modified graphene, the preparation method of which is as follows: Graphene oxide was added to 20 times the mass of tetrahydrofuran, stirred and dispersed, and cast into a film with a casting thickness of 40 μm, and then vacuum dried at 40°C for 12 hours; In an ambient atmosphere with a volume content of N2 / H2=96:4, the temperature was raised to 800°C at 5°C / min and calcined for 40 minutes, and then air flow crushed to obtain vertically oriented modified graphene.

[0038] The orientation rate of the vertically oriented modified graphene was found to be 34.6%, which is less than 60%. Preparation Example 4 A silver nanowire, the preparation method of which is as follows: Add 340g silver nitrate and 1080g PVP K30 into 20L ethylene glycol and stir magnetically until completely dissolved. Under nitrogen protection, heat the oil bath to 160℃±2℃ and continue stirring (300 rpm) for 2 h; The samples were centrifugally washed three times with anhydrous ethanol at a speed of 8000 rpm for 10 minutes each time. After washing, the samples were vacuum dried at 40°C to obtain the initial silver nanowires. Dissolve 20 g of dopamine hydrochloride in 10 L of Tris buffer (pH = 8.5) and stir to dissolve; 100 g of initial silver nanowire powder was added to the above solution and ultrasonically dispersed (40 kHz, 100 W) for 10 min; Then, the reaction was carried out under magnetic stirring at room temperature of 25°C in a closed environment for 12 h; The sample was centrifuged and washed three times with deionized water at a speed of 6000 rpm, with each washing time being 15 min.

[0039] Then the silver nanowires were obtained by vacuum drying at 40 °C for 12 h.

[0040] The diameter of the silver nanowires was detected to be 30±5nm, and the aspect ratio was 1400.

[0041] Preparation Example 5 A silver nanowire, the preparation method of which is as follows: Add 272g silver nitrate and 1440g PVP K30 into 20L ethylene glycol and stir magnetically until completely dissolved. Under nitrogen protection, heat the oil bath to 150℃±2℃ and continue stirring (400 rpm) for 3 h; The samples were centrifugally washed three times with anhydrous ethanol at a speed of 8000 rpm for 10 minutes each time. After washing, the samples were vacuum dried at 40°C to obtain the initial silver nanowires. Dissolve 20 g of dopamine hydrochloride in 10 L of Tris buffer (pH = 8.5) and stir to dissolve; 100 g of initial silver nanowire powder was added to the above solution and ultrasonically dispersed (40 kHz, 100 W) for 10 min; Then, the reaction was carried out under magnetic stirring at room temperature of 25°C in a closed environment for 12 h; The sample was centrifuged and washed three times with deionized water at a speed of 6000 rpm, with each washing time being 15 min.

[0042] Then the silver nanowires were obtained by vacuum drying at 40 °C for 12 h.

[0043] The diameter of the silver nanowires was detected to be 20±5 nm, and the aspect ratio was 1400.

[0044] Preparation Example 6 A silver nanowire, the preparation method of which is as follows: Add 510g silver nitrate and 720g PVP K30 into 20L ethylene glycol and stir magnetically until completely dissolved. Under nitrogen protection, heat the oil bath to 170℃±2℃ and continue stirring (200 rpm) for 1.5 h; The samples were centrifugally washed three times with anhydrous ethanol at a speed of 8000 rpm for 10 minutes each time. After washing, the samples were vacuum dried at 40°C to obtain the initial silver nanowires. Dissolve 20 g of dopamine hydrochloride in 10 L of Tris buffer (pH = 8.5) and stir to dissolve; 100 g of initial silver nanowire powder was added to the above solution and ultrasonically dispersed (40 kHz, 100 W) for 10 min; Then, the reaction was carried out under magnetic stirring at room temperature of 25°C in a closed environment for 12 h; The sample was centrifuged and washed three times with deionized water at a speed of 6000 rpm, with each washing time being 15 min.

[0045] Then the silver nanowires were obtained by vacuum drying at 40 °C for 12 h.

[0046] The diameter of the silver nanowires was detected to be 50±5nm, and the aspect ratio was 1400.

[0047] Preparation Example 7 A silver nanowire, the preparation method of which is as follows: Add 408g silver nitrate and 972g PVP K30 into 20L ethylene glycol and stir magnetically until completely dissolved. Under nitrogen protection, heat the oil bath to 155°C ± 2°C and continue stirring (400 rpm) for 1.5 h; The samples were centrifugally washed three times with anhydrous ethanol at a speed of 8000 rpm for 10 minutes each time. After washing, the samples were vacuum dried at 40°C to obtain the initial silver nanowires. Dissolve 20 g of dopamine hydrochloride in 10 L of Tris buffer (pH = 8.5) and stir to dissolve; 100 g of initial silver nanowire powder was added to the above solution and ultrasonically dispersed (40 kHz, 100 W) for 10 min; Then, the reaction was carried out under magnetic stirring at room temperature of 25°C in a closed environment for 12 h; The sample was centrifuged and washed three times with deionized water at a speed of 6000 rpm, with each washing time being 15 min.

[0048] Then the silver nanowires were obtained by vacuum drying at 40 °C for 12 h.

[0049] The diameter of the silver nanowires was detected to be 30±5nm, and the aspect ratio was 1200.

[0050] Preparation Example 8 A silver nanowire, the preparation method of which is as follows: Add 272g silver nitrate and 1296g PVP K30 to 20L ethylene glycol and stir magnetically until completely dissolved. Under nitrogen protection, heat the oil bath to 165°C ± 2°C and continue stirring (250 rpm) for 3 h; The samples were centrifugally washed three times with anhydrous ethanol at a speed of 8000 rpm for 10 minutes each time. After washing, the samples were vacuum dried at 40°C to obtain the initial silver nanowires. Dissolve 20 g of dopamine hydrochloride in 10 L of Tris buffer (pH = 8.5) and stir to dissolve; 100 g of initial silver nanowire powder was added to the above solution and ultrasonically dispersed (40 kHz, 100 W) for 10 min; Then, the reaction was carried out under magnetic stirring at room temperature of 25°C in a closed environment for 12 h; The sample was centrifuged and washed three times with deionized water at a speed of 6000 rpm, with each washing time being 15 min.

[0051] Then the silver nanowires were obtained by vacuum drying at 40 °C for 12 h.

[0052] The diameter of the silver nanowires was detected to be 30±5nm, and the aspect ratio was 1500.

[0053] Preparation Example 9 A silver nanowire, the preparation method of which is as follows: Add 340g silver nitrate and 1080g PVP K30 into 20L ethylene glycol and stir magnetically until completely dissolved. Under nitrogen protection, heat the oil bath to 160℃±2℃ and continue stirring (300 rpm) for 2 h; The silver nanowires were obtained by centrifugal washing three times with anhydrous ethanol at a centrifugal washing speed of 8000 rpm and each washing time of 10 minutes. After washing, the silver nanowires were vacuum dried at 40°C.

[0054] The diameter of the silver nanowires was detected to be 30±5nm, and the aspect ratio was 1400.

[0055] Example 1 A graphene-modified antistatic cable shielding layer material is prepared from the following raw materials: Hydrogenated nitrile rubber matrix 72kg, 4.7 kg of vertically aligned modified graphene prepared in Preparation Example 1, 11.2 kg of diionic liquid, 1.8 kg of cross-linking agent.

[0056] The diionic liquid is prepared by mixing 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and trihexyltetradecylphosphine bis(trifluoromethanesulfonyl)imide salt in a molar ratio of 1:1.5.

[0057] The crosslinking agent is tetrathiodiethyl diisocyanate.

[0058] A graphene-modified antistatic cable material, the preparation method of which is as follows: The hydrogenated nitrile rubber matrix and the vertically aligned modified graphene prepared in Preparation Example 1 were added to a mixer and mixed at 80° C. and 40 rpm for 5 minutes to obtain a first mixed material; A diionic liquid was added to the first mixture, and the mixture was mixed at 60° C. and 30 rpm for 18 minutes to obtain a second mixture. A cross-linking agent was added to the second mixture, and the mixture was mixed at 70° C. and 15 rpm for 3 minutes to obtain a graphene-modified antistatic cable shielding layer material.

[0059] The cable shielding layer material is attached to the outside of the wire harness by extrusion coating, and then vulcanized and cured through a continuous vulcanization process to form a shielding layer.

[0060] Comparative Example 1 A cable shielding layer material is disclosed, which differs from Example 1 in that no diionic liquid is added to the raw materials and the vertically oriented modified graphene prepared in Preparation Example 1 is also not added.

[0061] The hydrogenated nitrile rubber matrix was mixed at 80° C. and 40 rpm for 5 minutes to obtain a first mixed material; The first mixed material was mixed at 60°C and 30 rpm for 18 minutes to obtain the second mixed material. A cross-linking agent was added to the second mixed material, and the mixture was mixed at 70° C. and 15 rpm for 3 minutes to obtain a cable shielding layer material.

[0062] Comparative Example 2 A cable shielding layer material is disclosed, which differs from Example 1 in that the vertically oriented modified graphene prepared in Preparation Example 1 is not added, and the first mixed material is obtained by mixing a hydrogenated nitrile rubber matrix at 80° C. and 40 rpm for 5 minutes.

[0063] Comparative Example 3 A cable shielding layer material is disclosed, which differs from Example 1 in that no diionic liquid is added to the raw materials, and the vertically oriented modified graphene prepared in Preparation Example 1 is replaced by an equal mass of modified graphene prepared in Preparation Example 2.

[0064] The preparation method is as follows: The hydrogenated nitrile rubber matrix and the vertically aligned modified graphene prepared in Preparation Example 2 were added to a mixer and mixed at 80° C. and 40 rpm for 5 minutes to obtain a first mixed material; The first mixed material was mixed at 60°C and 30 rpm for 18 minutes to obtain a second mixed material. A cross-linking agent was added to the second mixed material, and the mixture was mixed at 70° C. and 15 rpm for 3 minutes to obtain a graphene-modified antistatic cable shielding layer material.

[0065] Comparative Example 4 A cable shielding layer material is provided. The difference between the material and Example 1 is that no diionic liquid is added to the raw materials. The first mixed material is mixed at 60° C. and 30 rpm for 18 minutes to obtain a second mixed material.

[0066] Example 2 A cable shielding layer material is disclosed, which differs from Example 1 in that no diionic liquid is added to the raw materials, and the vertically oriented modified graphene prepared in Preparation Example 1 is replaced by an equal mass of modified graphene prepared in Preparation Example 3.

[0067] The preparation method is as follows: The hydrogenated nitrile rubber matrix and the vertically aligned modified graphene prepared in Preparation Example 3 were added to a mixer and mixed at 80° C. and 40 rpm for 5 minutes to obtain a first mixed material; The first mixed material was mixed at 60°C and 30 rpm for 18 minutes to obtain a second mixed material. A cross-linking agent was added to the second mixed material, and the mixture was mixed at 70° C. and 15 rpm for 3 minutes to obtain a graphene-modified antistatic cable shielding layer material.

[0068] Example 3 A graphene-modified antistatic cable shielding layer material is prepared from the following raw materials: Hydrogenated nitrile rubber matrix 72kg, 4.7 kg of vertically aligned modified graphene prepared in Preparation Example 1, 11.2 kg of diionic liquid, Cross-linking agent 1.8kg, Preparation Example 4 produced 0.47 kg of silver nanowires.

[0069] The diionic liquid is prepared by mixing 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and trihexyltetradecylphosphine bis(trifluoromethanesulfonyl)imide salt in a molar ratio of 1:1.5.

[0070] The crosslinking agent is tetrathiodiethyl diisocyanate.

[0071] A graphene-modified antistatic cable material, the preparation method of which is as follows: The hydrogenated nitrile rubber matrix and the vertically aligned modified graphene prepared in Preparation Example 1 were added to a mixer and mixed at 80° C. and 40 rpm for 5 minutes to obtain a first mixed material; The diionic liquid was added to the first mixture, and the mixture was mixed at 60° C. and 30 rpm for 8 min to obtain a second mixture. The silver nanowires prepared in Preparation Example 4 were added to the second mixture, and the mixture was mixed at 90° C. and 20 rpm for 10 min to obtain a third mixture. A cross-linking agent was added to the third mixture, and the mixture was mixed at 70° C. and 15 rpm for 3 minutes to obtain a graphene-modified antistatic cable shielding layer material.

[0072] The cable shielding layer material is attached to the outside of the wire harness by extrusion coating, and then vulcanized and cured through a continuous vulcanization process to form a shielding layer.

[0073] Example 4 A cable shielding layer material, which differs from Example 3 in that the silver nanowires prepared in Preparation Example 4 are replaced by the silver nanowires prepared in Preparation Example 5 of equal mass, and the third mixed material is obtained by mixing the second mixed material and the silver nanowires prepared in Preparation Example 5 at 90°C and 20 rpm for 10 minutes.

[0074] Example 5 A cable shielding layer material, which differs from Example 3 in that the silver nanowires prepared in Preparation Example 4 are replaced by the silver nanowires prepared in Preparation Example 6 of equal mass, and the third mixed material is obtained by mixing the second mixed material and the silver nanowires prepared in Preparation Example 6 at 90°C and 20 rpm for 10 minutes.

[0075] Example 6 A cable shielding layer material, which differs from Example 3 in that the silver nanowires prepared in Preparation Example 4 are replaced by the silver nanowires prepared in Preparation Example 7 of equal mass, and the third mixed material is obtained by mixing the second mixed material and the silver nanowires prepared in Preparation Example 7 at 90°C and 20 rpm for 10 minutes.

[0076] Example 7 A cable shielding layer material, which differs from Example 3 in that the silver nanowires prepared in Preparation Example 4 are replaced by the silver nanowires prepared in Preparation Example 8 of equal mass, and the third mixed material is obtained by mixing the second mixed material and the silver nanowires prepared in Preparation Example 8 at 90°C and 20 rpm for 10 minutes.

[0077] Example 8 A cable shielding layer material, which differs from Example 3 in that the silver nanowires prepared in Preparation Example 9 are replaced by the silver nanowires prepared in Preparation Example 4, and the third mixed material is obtained by mixing the second mixed material and the silver nanowires prepared in Preparation Example 9 at 90°C and 20 rpm for 10 minutes.

[0078] Example 9 A cable shielding layer material, which differs from Example 3 in that the cross-linking agent is dicumyl peroxide, and the masses used are equal.

[0079] Example 10 A cable shielding layer material, which differs from Example 3 in that the cross-linking agent is zinc diethyldithiocarbamate, and the masses used are equal.

[0080] Example 11 A cable shielding layer material, which differs from Example 3 in that the amount of raw materials used is different. The specific amount of raw materials used is as follows: 60 kg of hydrogenated nitrile rubber matrix, Preparation Example 1: 3 kg of vertically aligned modified graphene and 8 kg of diionic liquid. Cross-linking agent 1kg, Preparation Example 4 produced 0.3 kg of silver nanowires.

[0081] Example 12 A cable shielding layer material, which differs from Example 3 in that the amount of raw materials used is different. The specific amounts of raw materials used are as follows: 75 kg of hydrogenated nitrile rubber matrix, Preparation Example 1: 5 kg of vertically aligned modified graphene and 12 kg of diionic liquid. 2kg cross-linking agent, Preparation Example 4 produced 0.5 kg of silver nanowires.

[0082] The cable shielding layer materials obtained in Examples 1 to 12 and Comparative Examples 1 to 4 were tested, and the test contents are as follows.

[0083] Density was tested according to ASTM D792 using the buoyancy method, and the average value of three groups was taken.

[0084] Shielding performance testing is based on the IEC 62153-4-3 triaxial method, 1GHz / 10GHz dual-frequency testing.

[0085] The volume resistivity was measured according to ASTM D257 at 500 V DC and 23°C.

[0086] The bending life is tested according to ASTM D430 with a radius of 20 mm and a frequency of 1 Hz.

[0087] Cyclic anti-static decay is tested according to ANSI / ESD STM11.12, and the time taken for 500V discharge to 10% is measured.

[0088] The test results are shown in Table 1.

[0089] Table 1. Test results of cable shielding layer materials obtained in Examples 1 to 12 and Comparative Examples 1 to 4 Combined with Table 1, it can be seen that, by comparing Example 1 and Comparative Example 1, Example 1 simultaneously adds vertically oriented modified graphene and diionic liquid, while Comparative Example 1 does not add any graphene and ionic liquid 1 to the raw materials. Although the density of Example 1 is improved, the increase is not obvious.

[0090] Therefore, in the present application, the addition of vertically oriented modified graphene and diionic liquid to the hydrogenated nitrile rubber-based cable shielding layer material has little effect on the weight of the cable shielding layer material.

[0091] Comparing Comparative Example 1 and Comparative Example 2, the shielding performance of Comparative Example 2 is similar to that of Comparative Example 1, and the antistatic performance of Comparative Example 2 is improved compared with that of Comparative Example 1. In addition, the bending life of Comparative Example 1 and Comparative Example 2 is similar. Therefore, for the cable shielding layer material of the hydrogenated nitrile rubber matrix of the present application, the addition of a diionic liquid can improve the antistatic performance of the shielding layer material.

[0092] Comparing Comparative Example 1 and Comparative Example 3, the shielding performance and bending life of Comparative Example 3 are improved compared with Comparative Example 1. In addition, the antistatic performance of Comparative Example 3 is slightly improved compared with Comparative Example 1. The addition of graphene improves the shielding performance of the shielding layer material by reflecting electromagnetic waves between the graphene sheets, and strengthens the strength performance of the shielding layer material by combining graphene with the substrate.

[0093] Comparing Comparative Example 3 and Comparative Example 4, the shielding performance of Comparative Example 4 is improved compared with Comparative Example 3. This shows that the vertically oriented modified graphene has a better effect on improving the shielding performance.

[0094] Furthermore, comparing Example 1 with Comparative Examples 1 to 4, the shielding performance of Example 1 is significantly improved compared with Comparative Example 4, and the improvement is far greater than the improvement of Comparative Example 2 compared with Comparative Example 1. The antistatic performance of Example 1 is significantly improved compared to that of Comparative Example 4, and the improvement is much greater than that of Comparative Example 4 compared to Comparative Example 1. In addition, the bending life of Example 1 is significantly improved compared to Example 4; From this verification, it can be seen that the addition of vertically oriented modified graphene and diionic liquid in the hydrogenated nitrile rubber matrix of the present application can play a synergistic role. The oxygen-containing groups (-COOH, -OH) on the graphene surface form hydrogen bonds with the imidazole ring / phosphine group of the ionic liquid. The hydrogen bonding inhibits graphene agglomeration and improves the dispersion stability of the ionic liquid in the matrix. The electronic conductive network of vertical graphene and the ion migration path of diionic liquid (cation [EMIM] + Bulk phase migration and anion [P66614]-surface adsorption) form dual conductive paths, covering the full frequency band charge regulation; This enhances the shielding performance of the vertically oriented modified graphene and the antistatic effect of the diionic liquid, thereby achieving long-term stable high shielding and antistatic safety of the shielding layer material of the present application.

[0095] By comparing Example 1 and Example 2, it can be seen that the vertically oriented modified graphene used in Example 1 adopts polystyrene microspheres as a filling template during the preparation process. The orientation rate of the vertically oriented modified graphene used in Example 1 is significantly greater than that of the vertically oriented modified graphene directly adopted by the casting method in Comparative Example 2. The shielding performance, antistatic performance, and bending life of Example 1 are all better than those of Example 2. It can be seen that the greater the orientation rate of the vertically oriented modified graphene in this application, the more obvious its shielding performance enhancement effect and the synergistic effect with the double ions are.

[0096] In this application, polyethylene microspheres are used as filling templates to modify the vertical orientation of graphene. The modification method is relatively convenient and has a good modification effect.

[0097] Comparing Example 1 and Example 3, Example 3 is based on Example 1, and further comprises adding the silver nanowires prepared in Preparation Example 4 of the present application to the original raw materials.

[0098] The silver nanowires are prepared by reducing silver nitrate in a hot ethylene glycol environment. The precipitated silver microcrystals are affected by PVP adsorption to form silver nanowires with a diameter of 30±5 nanometers and an aspect ratio of 1400.

[0099] Silver nanowires with this diameter and high aspect ratio fill the gaps in the graphene sheets through a "wire-surface" interpenetrating structure to form a three-dimensional conductive network. This can improve the high-frequency shielding effectiveness and reduce the defect rate of the conductive network while slightly increasing the material density, making the densities of Example 1 and Example 3 similar, while the shielding performance and antistatic performance of Example 3 are improved compared to Example 1.

[0100] Comparing Example 3 with Examples 4 to 7, the densities of Example 3 and Examples 4 to 7 are similar, but the shielding performance and antistatic performance of Example 3 are better than those of Examples 4 to 6; the antistatic performance and shielding performance of Example 7 are similar to those of Example 1.

[0101] The silver nanowires used in Example 7 were prepared in Preparation Example 8. Since the aspect ratio of the target product in Preparation Example 8 was too large, the preparation time was long and the yield was low.

[0102] Based on the above considerations, the silver nanowires of the present application are preferably selected with a diameter of 30 nm and an aspect ratio of 1400.

[0103] Comparing Example 3 and Example 8, the silver nanowires used in Example 3 are compared with the silver nanowires used in Example 8. The outer side of the silver nanowires is adsorbed and polymerized by dopamine hydrochloride to form a polydopamine attachment layer, and the interface bonding is enhanced by Ag-O and π-π bond conjugation, thereby improving the oxidation resistance of the silver nanowires. The silver nanowires have better oxidation resistance and dispersion stability during the production and secondary processing of the shielding layer material of the present application, thereby ensuring the enhancement effect of the silver nanowires. Therefore, the shielding performance and antistatic performance of Example 3 of the present application are better than those of Example 8.

[0104] Comparing Example 3 and Example 9, the cross-linking agent used in Example 3 is tetrathiodiethyl diisocyanate, and the cross-linking agent used in Example 9 is diisopropyl benzene peroxide. Compared with diisopropyl benzene peroxide, tetrathiodiethyl diisocyanate contains disulfide bonds, and disulfide bonds can undergo reversible breakage and recombination under high temperature environments, giving the shielding layer material of the present application self-healing properties, which is beneficial to the bending performance of the cable shielding layer formed by the shielding layer material of the present application after secondary processing. Therefore, the bending life of the cable shielding layer material in Example 3 of the present application is better than that in Example 9.

[0105] Comparing Example 3 and Example 10, the anti-shielding performance, antistatic performance and bending life of Example 3 are better than those of Example 10. Therefore, among the cross-linkers containing disulfide bonds, the shielding layer material obtained by tetrathiodiethyl diacetylenate selected in this application has better performance.

[0106] In addition, during the research and development process, this application also obtained better examples of other raw material usage ratio ranges, such as Examples 11 and 12 of this application. It can be seen that when the raw material usage of the shielding layer material of this application is controlled within the following range, it obtains long-term better shielding performance and anti-static performance.

[0107] Example 13 A mining cable comprises a battery core, an insulation layer, a shielding layer, and a sheath layer. The shielding layer is made of a graphene-modified antistatic cable shielding layer material, and the graphene-modified antistatic cable shielding layer material is one of Examples 1 to 12.

[0108] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as the modifications are within the scope of protection required by the present invention, they will be protected by patent law.

Claims

1. A graphene-modified antistatic cable shielding material, characterized in that: It includes the following components by weight: 60~75 parts of hydrogenated nitrile rubber matrix, 3~5 parts of vertically oriented modified graphene, 8~12 parts of diionic liquid, 1~2 parts of cross-linking agent; The orientation degree of the vertically oriented modified graphene is greater than 60%; The diionic liquid is a compound of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and trihexyltetradecylphosphine bis(trifluoromethanesulfonyl)imide salt.

2. The graphene-modified antistatic cable shielding layer material according to claim 1, characterized in that: The method for adjusting the vertical orientation of the modified graphene is as follows: Graphene oxide and polystyrene microspheres are dispersed in THF, and after the polystyrene microspheres swell, they are cast into a film, and then calcined in an inert atmosphere to remove the polystyrene to obtain vertically oriented modified graphene.

3. The graphene-modified antistatic cable shielding layer material according to claim 1, characterized in that: The invention comprises 0.3 to 0.5 parts of silver nanowires, wherein the diameter of the silver nanowires is 30±5 nm and the aspect ratio is 1200 to 1500.

4. The graphene-modified antistatic battery material according to claim 3, characterized in that: The aspect ratio of the silver nanowires is 1400.

5. The graphene-modified antistatic cable shielding layer material according to claim 3, characterized in that: The silver nanowires are surface-modified with polydopamine.

6. The graphene-modified antistatic cable shielding layer material according to claim 1, characterized in that: The cross-linking agent is a dynamic cross-linking agent containing a disulfide bond.

7. The graphene-modified antistatic cable shielding layer material according to claim 6, characterized in that: The cross-linking agent is tetrathiodiethyl diisocyanate.

8. A mining cable, characterized by: The invention comprises a battery core, an insulating layer, a shielding layer and a sheath layer, wherein the shielding layer is obtained from the graphene-modified antistatic cable shielding layer material according to any one of claims 1 to 7.

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