EPTFE-based cable shielding layer material and processing method thereof

Abstract

The invention relates to the technical field of PTFE materials, in particular to an ePTFE-based cable shielding layer material and a processing method thereof. The processing method comprises the following steps: S1, uniformly mixing dispersed PTFE resin, modified carbon fibers and a lubricant, and carrying out extrusion pushing, rolling, baking, stretching and sintering to obtain an ePTFE film; s2, performing plasma treatment on one surface or two surfaces of the ePTFE membrane to obtain a modified ePTFE membrane; s3, after S2, immediately immersing the modified ePTFE membrane into a dopamine solution, soaking overnight, and drying to obtain a dopamine modified ePTFE membrane; and S4, uniformly coating a modified acrylate adhesive on the surface of the dopamine modified ePTFE film subjected to low-temperature plasma treatment, then pasting an aluminum foil on the surface, and carrying out pressing, drying and curing to obtain the ePTFE-based cable shielding layer material.

Description

Technical Field

[0001] This invention relates to the field of PTFE material technology, specifically to an ePTFE-based cable shielding layer material and its processing method. Background Technology

[0002] With the surge in demand for high-speed data transmission in fields such as 5G communications and aerospace, the development of lightweight cable materials with high shielding effectiveness has become a key technological development direction. Expanded polytetrafluoroethylene (ePTFE) film, with its excellent dielectric properties, chemical stability, microporous structure, and lightweight characteristics, is considered an ideal high-frequency shielding substrate. However, ePTFE film also has low mechanical strength and poor adhesion to metal foils (such as aluminum foil), resulting in cable shielding materials with short service life and unstable electrical shielding performance.

[0003] Based on this, the present invention proposes an ePTFE-based cable shielding layer material and its processing method, which greatly solves the existing defects and is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide an ePTFE-based cable shielding material and its processing method to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for processing an ePTFE-based cable shielding material includes the following steps: S1: After uniformly mixing dispersed PTFE resin, modified carbon fiber, and lubricant, the mixture is extruded, rolled, baked, stretched, and sintered to obtain an ePTFE membrane. S2: Plasma treatment is performed on one or both surfaces of the ePTFE membrane to obtain a modified ePTFE membrane; S3: Immediately after S2, the modified ePTFE membrane is immersed in a dopamine solution, soaked overnight, and dried to obtain a dopamine-modified ePTFE membrane; S4: A modified acrylate adhesive is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment, and then aluminum foil is attached to the surface. After pressing, drying and curing, ePTFE-based cable shielding material is obtained.

[0006] Furthermore, the ePTFE membrane comprises the following raw material components: 50 parts by weight of dispersed PTFE resin, 10 to 15 parts by modified carbon fiber, and 10 to 20 parts by weight of lubricant.

[0007] Furthermore, the dispersed PTFE resin is graded PTFE F1000 and has a compression ratio of 1200:1.

[0008] Furthermore, the method for preparing the modified carbon fiber is as follows: (1) In an air atmosphere, heat the carbon fiber to 380℃~420℃ and hold for 30min~60min, then let it cool naturally to room temperature to obtain oxidized carbon fiber; (2) Add the fluorinated silane coupling agent to a 95wt% ethanol solution and sonicate for 30min~60min to obtain a silane hydrolysate; (3) Immerse the oxidized carbon fiber in silane hydrolysate, stir and mix evenly, soak for 2h~4h, filter, and dry to obtain modified carbon fiber.

[0009] Furthermore, the aspect ratio of the carbon fiber is (10~20):1.

[0010] Furthermore, the ratio of the fluorinated silane coupling agent to the 95wt% ethanol solution is (1~2)g:100mL.

[0011] Furthermore, the fluorinated silane coupling agent includes, but is not limited to, any one of (3,3,3-trifluoropropyl)methyldimethoxysilane, (3,3,3-trifluoropropyl)methyldiethoxysilane, (3,3,3-trifluoropropyl)trimethoxysilane, and (3,3,3-trifluoropropyl)triethoxysilane.

[0012] Furthermore, the ratio of the oxidized carbon fiber to the silane hydrolysate is 1g:10mL.

[0013] Furthermore, the lubricant is an isoparaffin.

[0014] Furthermore, the specific process of S1 is as follows: (1) At 10℃~19℃, the dispersed PTFE resin, modified carbon fiber and lubricant are mixed evenly, and then left to stand overnight at 30~40℃ to preform into a blank rod PTFE material. (2) At 40℃~60℃, the PTFE material in the shape of a billet is extruded to obtain a PTFE sheet of 2mm~3mm; then the temperature is further raised to 60℃~80℃, and the PTFE sheet of 2mm~3mm is rolled to obtain a PTFE film of 0.3mm~0.5mm. (3) Place the PTFE membrane in a drying oven at 120℃~150℃ and bake for 4h~8h; (4) Further heat the PTFE film baked in (3) to 240℃~280℃, and stretch it 2 to 6 times along the rolling direction at a stretching rate of 10% / s~20% / s; (5) Heat the stretched PTFE membrane in (4) to 350℃~380℃ and sinter for 5min~10min to obtain ePTFE membrane.

[0015] Furthermore, the process parameters for the plasma treatment are as follows: the treatment gas is air, the gas pressure is 20Pa~30Pa, the power is 150W~250W, and the treatment time is 2min~6min.

[0016] Furthermore, the dopamine solution is a dopamine Tris solution with a concentration of 0.01 mol / L to 0.02 mol / L and a pH of 8 to 8.5.

[0017] Furthermore, the modified acrylic adhesive is prepared by: (1) Under nitrogen protection, acrylic monomer, 3-acryloyldopamine, vinyl silane coupling agent, NP-10 and anhydrous ethanol are stirred and mixed for 1h~2h and pre-emulsified to obtain emulsion reaction solution; (2) Azobisisobutyronitrile and anhydrous ethanol were stirred and mixed evenly to obtain a 10wt% initiator solution; (3) After stirring the emulsion reaction solution and heating it to 70℃~80℃, slowly add the initiator solution dropwise for 2 hours while stirring. After the addition is complete, continue stirring for 4~8 hours to stop the reaction and obtain the modified acrylic adhesive.

[0018] Furthermore, the raw material components required for the preparation of the modified acrylate adhesive are as follows: by weight, 30 parts of acrylate monomer, 8 to 12 parts of 3-acryloyldopamine, 3 to 5 parts of vinyl silane coupling agent, 0.3 to 0.5 parts of NP-10, 0.5 to 1 part of azobisisobutyronitrile, and 41 to 47 parts of anhydrous ethanol; wherein the ratio of solvent mass to monomer mass is 1:1.

[0019] Furthermore, the acrylate monomers include, but are not limited to, one or more combinations of acrylic acid, ethyl acrylate, butyl acrylate, and methyl methacrylate.

[0020] Furthermore, the vinyl silane coupling agent includes, but is not limited to, any one of vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltriisopropoxysilane.

[0021] Furthermore, the thickness of the coated wet film is 6μm~12μm.

[0022] Furthermore, the thickness of the aluminum foil is 12μm~30μm.

[0023] Furthermore, the pressing parameters are: pressure of 0.5MPa~1MPa, and pressing time of 10s~30s.

[0024] Furthermore, the drying and curing parameters are as follows: drying temperature is 80℃~100℃, and curing time is 1h~2h.

[0025] Furthermore, the ePTFE-based cable shielding material obtained by the processing method of the aforementioned ePTFE-based cable shielding material.

[0026] Compared with the prior art, the beneficial effects achieved by the present invention are: (1) Due to the defects of high thermal expansion coefficient and low mechanical strength of ePTFE, the present invention first performs high-temperature oxidation treatment on carbon fiber to make its surface contain sufficient oxygen-containing functional groups, and then further modifies it with fluorinated silane coupling agent to prepare modified carbon fiber; the modified carbon fiber has good compatibility with PTFE, and after sintering, it is tightly bonded to the PTFE interface, which can greatly enhance the mechanical strength of the ePTFE film obtained later, and also improve its thermal stability; since the ePTFE film is relatively thin, the aspect ratio of the carbon fiber is controlled at (10~20):1 to better enhance the mechanical strength of the ePTFE film; the modification of the modified carbon fiber in the scheme should not be too strong, and some oxygen-containing functional groups can be retained, which helps to bind with dopamine adsorption later.

[0027] (2) In this invention, the ePTFE membrane is subjected to plasma treatment in an air atmosphere, which can introduce active groups such as oxygen-containing functional groups on the surface of the ePTFE membrane and enhance the surface energy of the ePTFE membrane. In this invention, plasma treatment provides a prerequisite for immersing the ePTFE membrane in a dopamine solution. After plasma treatment, the ePTFE membrane can effectively adsorb and bind with dopamine in the dopamine solution, and then self-polymerize to form an adhesive polydopamine coating on the surface of the ePTFE membrane. The polydopamine coating can play the role of connecting the ePTFE membrane and the modified acrylate adhesive. Compared with directly coating the ePTFE membrane surface with adhesive, the bonding performance between the ePTFE membrane and the aluminum foil layer can be better enhanced by connecting through the polydopamine layer.

[0028] (3) The plasma treatment should not be too weak, as too weak a plasma treatment will not activate the ePTFE membrane sufficiently, while too strong a plasma treatment will damage the surface of the ePTFE membrane. In subsequent experiments, the bonding performance between the ePTFE membrane and the aluminum foil layer can be further controlled by controlling the plasma treatment parameters and the concentration of dopamine.

[0029] (4) A modified acrylate adhesive was prepared in this invention. The adhesive contains a dopamine structure and silane segments. The dopamine structure can form strong covalent and hydrogen bonds with the polydopamine layer on the surface of the ePTFE membrane, which plays an important role in enhancing the bonding performance between the ePTFE membrane and the aluminum foil. The silane segments can form strong covalent bonds with the aluminum foil layer, which further ensures the bonding performance between the ePTFE membrane and the aluminum foil.

[0030] In summary, this invention, through the synergistic effect of (1) modified carbon fiber reinforced PTFE; (2) plasma treatment and polydopamine layer setting on the subsequently prepared ePTFE membrane; and (3) a special modified acrylate adhesive, comprehensively prepares an ePTFE-based cable shielding layer material with a tight and reliable bond between the ePTFE membrane and aluminum foil layer, excellent mechanical strength, excellent electromagnetic shielding performance, and lightweight, which is of great significance. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that the following quantities are by weight, and there are no special restrictions on the suppliers of all raw materials involved in this invention. Exemplary examples include: In the following examples, PTFE F1000 with a compression ratio of 1200:1, brand name Hengfulong™, was manufactured by Guangzhou Dechuang New Materials Co., Ltd. Carbon fiber with aspect ratios of 15:1 and 30:1; NP-10, CAS number 9016-45-9; all purchased from Shanghai Maclean Biochemical Technology Co., Ltd. (3,3,3-trifluoropropyl)triethoxysilane, CAS No. 86876-45-1; vinyltriethoxysilane; both purchased from Sisbo Organosilicon Co., Ltd. Iso-dodecane, purchased from Shanghai Spectrum Biotechnology Co., Ltd. (Kramar); 3-Acryloyldopamine, CAS No. 201610-44-8, was purchased from Jiangsu Beida Pharmaceutical Technology Co., Ltd.; all other raw materials were commercially available; each part by weight was 100g.

[0033] Example 1: A processing method for an ePTFE-based cable shielding material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 15:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained. (2) (3,3,3-trifluoropropyl)triethoxysilane was added to a 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate. (3) The oxidized carbon fiber was immersed in the silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber. S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 12.5 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 25 Pa, the power is 200 W, and the treatment time is 4 min. S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.015 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 10 parts of 3-acryloyldopamine, 4 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0034] Example 2: A processing method for an ePTFE-based cable shielding layer material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 15:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained. (2) (3,3,3-trifluoropropyl)triethoxysilane was added to a 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate. (3) The oxidized carbon fiber was immersed in the silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber. S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 10 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 20Pa, the power is 150W, and the treatment time is 2min. S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.01 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 10 parts of 3-acryloyldopamine, 4 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0035] Example 3: A processing method for an ePTFE-based cable shielding layer material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 15:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained. (2) (3,3,3-trifluoropropyl)triethoxysilane was added to a 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate. (3) The oxidized carbon fiber was immersed in the silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber. S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 15 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 30Pa, the power is 250W, and the treatment time is 6min. S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.02 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane; S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 10 parts of 3-acryloyldopamine, 4 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0036] Example 4: A processing method for an ePTFE-based cable shielding layer material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 15:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained. (2) (3,3,3-trifluoropropyl)triethoxysilane was added to a 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate. (3) The oxidized carbon fiber was immersed in the silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber. S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 12.5 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 25 Pa, the power is 200 W, and the treatment time is 4 min. S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.015 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 8 parts of 3-acryloyldopamine, 3 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 33.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0037] Example 5: A processing method for an ePTFE-based cable shielding layer material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 15:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained. (2) (3,3,3-trifluoropropyl)triethoxysilane was added to a 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate. (3) The oxidized carbon fiber was immersed in the silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber. S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 12.5 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 25 Pa, the power is 200 W, and the treatment time is 4 min. S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.015 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 12 parts of 3-acryloyldopamine, 5 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 39.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0038] Comparative Example 1: Comparative Example 1 is based on Example 1, with the following adjustments: no modification treatment is applied to the carbon fiber, and other processes remain unchanged. Specifically: A method for processing ePTFE-based cable shielding material: S1. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 12.5 parts of carbon fiber (length-to-diameter ratio 15:1) and 15 parts of isomeric dodecane were mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material was extruded to obtain a 2.5 mm PTFE sheet; then the temperature was further raised to 70°C and the 2.5 mm PTFE sheet was rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane was placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) was further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) was heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 25 Pa, the power is 200 W, and the treatment time is 4 min. S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.015 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 10 parts of 3-acryloyldopamine, 4 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0039] Comparative Example 2: Comparative Example 2 is based on Example 1, with the following adjustment: the ePTFE membrane is not subjected to plasma treatment, while other processes remain unchanged. Specifically: A method for processing ePTFE-based cable shielding material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 15:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained. (2) (3,3,3-trifluoropropyl)triethoxysilane was added to a 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate. (3) The oxidized carbon fiber was immersed in the silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber. S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 12.5 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: The modified ePTFE membrane was immersed in a 0.015 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S3: S31. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 10 parts of 3-acryloyldopamine, 4 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S32. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0040] Comparative Example 3: Comparative Example 3 is based on Example 1, with the following adjustment: The modified ePTFE membrane was not immersed in the dopamine solution, while other processes remained unchanged. Specifically: A method for processing ePTFE-based cable shielding material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 15:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained. (2) (3,3,3-trifluoropropyl)triethoxysilane was added to a 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate. (3) The oxidized carbon fiber was immersed in the silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber. S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 12.5 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 25 Pa, the power is 200 W, and the treatment time is 4 min.

[0041] S3: S31. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 10 parts of 3-acryloyldopamine, 4 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S32. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0042] Comparative Example 4: Comparative Example 4 is based on Example 1, with the following adjustment: 3-acryloyldopamine is not added to the raw materials for preparing the modified acrylate adhesive, while other processes remain unchanged. Specifically: A method for processing ePTFE-based cable shielding material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 15:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained. (2) (3,3,3-trifluoropropyl)triethoxysilane was added to a 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate. (3) The oxidized carbon fiber was immersed in the silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber. S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 12.5 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 25 Pa, the power is 200 W, and the treatment time is 4 min.

[0043] S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.015 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 40 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 4 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0044] Comparative Example 5: Comparative Example 5 is based on Example 1, with the following adjustment: vinyltriethoxysilane is not added to the raw materials for preparing the modified acrylate adhesive, while other processes remain unchanged. Specifically: A method for processing ePTFE-based cable shielding material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 15:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained. (2) (3,3,3-trifluoropropyl)triethoxysilane was added to a 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate. (3) The oxidized carbon fiber was immersed in the silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber. S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 12.5 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 25 Pa, the power is 200 W, and the treatment time is 4 min.

[0045] S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.015 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 34 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 10 parts of 3-acryloyldopamine, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78℃, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0046] Comparative Example 6: Comparative Example 6 is based on Example 1, with the following adjustment: the aspect ratio of the carbon fiber is 30:1, while other processes remain unchanged. Specifically: A method for processing ePTFE-based cable shielding material: S1: S11. Preparation of modified carbon fiber: (1) In an air atmosphere, 25 parts of carbon fiber (length-to-diameter ratio 30:1) were heated to 400℃ and kept at that temperature for 45 min. After it was naturally cooled to room temperature, oxidized carbon fiber was obtained; (2) (3,3,3-trifluoropropyl)triethoxysilane was added to 95wt% ethanol solution (the ratio of (3,3,3-trifluoropropyl)triethoxysilane to 95wt% ethanol solution was 1.5g:100mL), and ultrasonic treatment was performed for 45 min to obtain silane hydrolysate; (3) The oxidized carbon fiber was immersed in silane hydrolysate (the ratio of oxidized carbon fiber to silane hydrolysate was 1g:10mL), stirred and mixed evenly, soaked for 3 h, filtered, and dried to obtain modified carbon fiber; S12. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000, 12.5 parts of modified carbon fiber and 15 parts of isomeric dodecane are mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material is extruded to obtain a 2.5 mm PTFE sheet; then the temperature is further raised to 70°C and the 2.5 mm PTFE sheet is rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane is placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) is further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) is heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 25 Pa, the power is 200 W, and the treatment time is 4 min. S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.015 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 10 parts of 3-acryloyldopamine, 4 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0047] Comparative Example 7: Comparative Example 7 is based on Example 1, with the following adjustment: carbon fiber is not added, while other processes remain unchanged. Specifically: A method for processing ePTFE-based cable shielding material: S1. Preparation of ePTFE membrane: (1) At 15°C, 50 parts of PTFE F1000 and 15 parts of isododecane were mixed evenly and then left to stand overnight at 35°C to preform into a rod-shaped PTFE material; (2) At 50°C, the rod-shaped PTFE material was extruded to obtain a 2.5 mm PTFE sheet; then the temperature was further raised to 70°C and the 2.5 mm PTFE sheet was rolled to obtain a 0.4 mm PTFE membrane; (3) The PTFE membrane was placed in a drying oven at 140°C and baked for 6 hours; (4) The PTFE membrane baked in (3) was further heated to 260°C and stretched 4 times along the rolling direction at a stretching rate of 15% / s; (5) The PTFE membrane stretched in (4) was heated to 370°C and sintered for 8 minutes to obtain an ePTFE membrane; S2: Plasma treatment is performed on one surface of the ePTFE membrane to obtain a modified ePTFE membrane; The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 25 Pa, the power is 200 W, and the treatment time is 4 min. S3: Immediately after S2, the modified ePTFE membrane was immersed in a 0.015 mol / L dopamine Tris solution (pH 8.2) overnight and then vacuum dried at 70°C to obtain the dopamine-modified ePTFE membrane. S4: S41. Preparation of modified acrylate adhesive: (1) Under nitrogen protection, 30 parts of acrylic monomer (acrylic acid, ethyl acrylate and methyl methacrylate mixed in a mass ratio of 1:1:1), 10 parts of 3-acryloyldopamine, 4 parts of vinyltriethoxysilane, 0.4 parts of NP-10 and 36.8 parts of anhydrous ethanol were stirred and mixed for 1.5 h to pre-emulsify and obtain an emulsion reaction solution; (2) 0.8 parts of azobisisobutyronitrile and 7.2 parts of anhydrous ethanol were stirred and mixed evenly to obtain a 10 wt% initiator solution; (3) The emulsion reaction solution was stirred and heated to 78°C, and then the initiator solution was slowly added dropwise for 2 h while stirring. After the addition was completed, the reaction was continued to be stirred for 8 h to end the reaction and obtain the modified acrylate adhesive; S42. A modified acrylate adhesive (10 μm wet film thickness) is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment. Then, a 25 μm thick aluminum foil is attached to the surface. After pressing under a pressure of 1 MPa for 20 s, the membrane is dried and cured at 90°C for 1.5 h to obtain the ePTFE-based cable shielding layer material.

[0048] Performance Test 1: The ePTFE films prepared in Examples 1-5 and Comparative Examples 1-7 were subjected to relevant mechanical property tests; the peel strength of the ePTFE-based cable shielding material was then tested, and the specific test methods are as follows: (1) Mechanical property test: According to the test standard of GB / T 1040.3-2006, at a temperature of 23℃ and a relative humidity of 50%, the ePTFE membrane was cut into a sample size of 150mm (length, stretch direction) × 15mm (width) along the stretching direction. Then, the ePTFE membrane was tested for tensile properties using a PC type electronic tensile testing machine DLS-07 at a stretching speed of 6mm / min. (2) Peel strength test: According to the test standard GB / T 8808-1988, at a temperature of 23℃ and a relative humidity of 50%, the ePTFE base cable shielding material is cut into a sample size of 200mm (length) × 15mm (width). Then, the ePTFE base cable shielding material sample is peeled 50mm along the length of the sample (the peeled part should not have obvious damage). Then, the peel strength test is carried out by using a PC type electronic tensile testing machine DLS-07 in a T-shaped tensile manner (the unpeeled part is T-shaped with the tensile direction). The tensile speed is 300mm / min.

[0049] The results of the above tests are shown in Table 1 below: Table 1

[0050] Results Analysis: Comparing the tensile strength results of Examples 1-3 and Comparative Examples 1 and 6-7 in Table 1 above, it can be seen that modified carbon fiber can greatly enhance the mechanical strength of the ePTFE membrane. Comparing the peel strength results of Examples 1-3, it can be seen that adjusting the parameters of plasma treatment and the dopamine concentration can affect the bonding strength between the ePTFE membrane and the aluminum foil layer to a certain extent. Comparing the peel strength results of Examples 1, Examples 4-5, and Comparative Examples 4-5, it can be seen that the dopamine structure and silane segments introduced in the modified acrylate adhesive prepared in this invention have a great influence on the bonding strength between the ePTFE membrane and the aluminum foil. Comparing the peel strength results of Examples 1 and Comparative Examples 2-3, it can be seen that plasma treatment and dopamine solution immersion of the ePTFE membrane in this invention are important technical points of this invention, and they have a great influence on the bonding strength between the ePTFE membrane and the aluminum foil.

[0051] Performance Test 2: Comparing the test results with those of Performance Test 1, and comprehensively comparing the test results of each embodiment and comparative example, it can be seen that Embodiment 5 is the optimal embodiment. Therefore, the electromagnetic shielding performance of the ePTFE-based cable shielding layer material prepared in Embodiment 5 is tested. The specific test method is as follows: According to the test standards of GB / T 32511-2016 and GB / T 30142-2013, the electromagnetic shielding performance of the ePTFE-based cable shielding layer material prepared in Example 5 was tested using the flange coaxial device method at a temperature of 23℃ and a phase humidity of 50% within the 18GHz frequency range. The test results are shown in Table 2 below. Table 2

[0052] Results Analysis: As can be seen from the data in Table 2 above, Example 5 achieved an electromagnetic shielding effectiveness of 64dB in the 18GHz frequency range, reaching the SE-1 shielding effectiveness level, indicating that the ePTFE-based cable shielding layer material prepared by this invention has excellent electromagnetic shielding performance.

[0053] In summary, this invention, through the synergistic effect of (1) modified carbon fiber reinforced PTFE; (2) plasma treatment and polydopamine layer setting on the subsequently prepared ePTFE membrane; and (3) a special modified acrylate adhesive, comprehensively prepares an ePTFE-based cable shielding layer material with a tight and reliable bond between the ePTFE membrane and aluminum foil layer, excellent mechanical strength, excellent electromagnetic shielding performance, and lightweight, which is of great significance.

[0054] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for processing an ePTFE-based cable shielding layer material, characterized in that: Includes the following steps: S1: After uniformly mixing dispersed PTFE resin, modified carbon fiber, and lubricant, the mixture is extruded, rolled, baked, stretched, and sintered to obtain an ePTFE membrane. S2: Plasma treatment is performed on one or both surfaces of the ePTFE membrane to obtain a modified ePTFE membrane; S3: Immediately after S2, the modified ePTFE membrane is immersed in a dopamine solution, soaked overnight, and dried to obtain a dopamine-modified ePTFE membrane; S4: A modified acrylate adhesive is uniformly coated on the surface of the dopamine-modified ePTFE membrane after low-temperature plasma treatment, and then aluminum foil is attached to the surface. After pressing, drying and curing, ePTFE-based cable shielding material is obtained. The ePTFE membrane comprises the following raw material components: 50 parts by weight of dispersed PTFE resin, 10 to 15 parts by modified carbon fiber, and 10 to 20 parts by weight of lubricant.

2. The processing method of an ePTFE-based cable shielding layer material according to claim 1, characterized in that: The method for preparing the modified carbon fiber is as follows: (1) In an air atmosphere, heat the carbon fiber to 380℃~420℃ and hold for 30min~60min, then let it cool naturally to room temperature to obtain oxidized carbon fiber; (2) Add the fluorinated silane coupling agent to a 95wt% ethanol solution and sonicate for 30min~60min to obtain a silane hydrolysate; (3) Immerse the oxidized carbon fiber in silane hydrolysate, stir and mix evenly, soak for 2h~4h, filter, and dry to obtain modified carbon fiber; Wherein, the aspect ratio of the carbon fiber is (10~20):1; The ratio of the fluorinated silane coupling agent and the 95wt% ethanol solution is (1~2)g:100mL; The fluorinated silane coupling agent includes any one of (3,3,3-trifluoropropyl)methyldimethoxysilane, (3,3,3-trifluoropropyl)methyldiethoxysilane, (3,3,3-trifluoropropyl)trimethoxysilane, and (3,3,3-trifluoropropyl)triethoxysilane. The ratio of the oxidized carbon fiber to the silane hydrolysate is 1g:10mL.

3. The processing method of an ePTFE-based cable shielding layer material according to claim 1, characterized in that: The specific process of S1 is as follows: (1) At 10℃~19℃, the dispersed PTFE resin, modified carbon fiber and lubricant are mixed evenly, and then left to stand overnight at 30~40℃ to preform into a blank rod PTFE material. (2) At 40℃~60℃, the PTFE material in the shape of a billet is extruded to obtain a PTFE sheet of 2mm~3mm; then the temperature is further raised to 60℃~80℃, and the PTFE sheet of 2mm~3mm is rolled to obtain a PTFE film of 0.3mm~0.5mm. (3) Place the PTFE membrane in a drying oven at 120℃~150℃ and bake for 4h~8h; (4) Further heat the PTFE film baked in (3) to 240℃~280℃, and stretch it 2 to 6 times along the rolling direction at a stretching rate of 10% / s~20% / s; (5) Heat the stretched PTFE membrane in (4) to 350℃~380℃ and sinter for 5min~10min to obtain ePTFE membrane.

4. The processing method of an ePTFE-based cable shielding layer material according to claim 1, characterized in that: The process parameters for plasma treatment are as follows: the treatment gas is air, the gas pressure is 20Pa~30Pa, the power is 150W~250W, and the treatment time is 2min~6min.

5. The processing method of an ePTFE-based cable shielding layer material according to claim 1, characterized in that: The dopamine solution is a dopamine Tris solution with a concentration of 0.01 mol / L to 0.02 mol / L and a pH of 8 to 8.

5.

6. The processing method of an ePTFE-based cable shielding layer material according to claim 1, characterized in that: The modified acrylic adhesive is prepared by: (1) Under nitrogen protection, acrylic monomer, 3-acryloyldopamine, vinyl silane coupling agent, NP-10 and anhydrous ethanol are stirred and mixed for 1h~2h and pre-emulsified to obtain emulsion reaction solution; (2) Azobisisobutyronitrile and anhydrous ethanol were stirred and mixed evenly to obtain a 10wt% initiator solution; (3) After stirring the emulsion reaction solution and heating it to 70℃~80℃, slowly add the initiator solution dropwise for 2 hours while stirring. After the addition is complete, continue stirring and reacting for 4~8 hours to end the reaction and obtain the modified acrylate adhesive. The raw material components required for preparing the modified acrylate adhesive are as follows (by weight): 30 parts acrylate monomer, 8-12 parts 3-acryloyldopamine, 3-5 parts vinyl silane coupling agent, 0.3-0.5 parts NP-10, 0.5-1 parts azobisisobutyronitrile, and 41-47 parts anhydrous ethanol; wherein the ratio of solvent mass to monomer mass is 1:

1.

7. The processing method of an ePTFE-based cable shielding layer material according to claim 6, characterized in that: The acrylate monomers include one or more combinations of acrylic acid, ethyl acrylate, butyl acrylate, and methyl methacrylate; The vinyl silane coupling agent includes any one of vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltriisopropoxysilane.

8. The processing method of an ePTFE-based cable shielding layer material according to claim 1, characterized in that: The thickness of the coated wet film is 6μm~12μm; The thickness of the aluminum foil is 12μm to 30μm.

9. A method for processing an ePTFE-based cable shielding layer material according to claim 1, characterized in that: The pressing parameters are: pressure of 0.5MPa to 1MPa and pressing time of 10s to 30s; The drying and curing parameters are: drying temperature of 80℃~100℃ and curing time of 1h~2h.

10. The ePTFE-based cable shielding material obtained by the processing method of the ePTFE-based cable shielding layer material according to any one of claims 1 to 9.

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