Multi-layer composite shielding PVC wire harness adhesive tape and preparation method thereof

Abstract

The invention discloses a multi-layer composite shielding PVC wire harness adhesive tape and a preparation method thereof, and relates to the technical field of PVC wire harness adhesive tape, the multi-layer composite shielding PVC wire harness adhesive tape comprises a base material layer, an adhesive layer and a stripping layer, the upper end of the base material layer is provided with a directional electromagnetic shielding layer, the upper end of the directional electromagnetic shielding layer is provided with an aerogel buffer layer, and the upper end of the aerogel buffer layer is provided with an adhesive layer. The directional electromagnetic shielding layer is formed by compounding MXene nanosheets and silver nanowires according to the mass ratio of (1: 0.3)-(1: 1). Polyimide fibers are embedded into pores of the silicon dioxide aerogel in a three-dimensional network structure, so that high buffering property and heat insulation property are realized, the problems that polyurethane foam is poor in heat insulation property and is easy to soften and lose efficacy in a high-temperature environment are solved, and the polyurethane foam is favorably used in an extreme environment and keeps certain stability.

Description

Technical Field

[0001] The present invention relates to the technical field of PVC wiring harness tapes, in particular to a multi-layer composite shielded PVC wiring harness tape and a preparation method thereof. Background Art

[0002] PVC wire harness tape is a composite material tape used for wire harness protection. Its core functions include electrical insulation, electromagnetic shielding, high temperature resistance, flame retardancy and mechanical protection.

[0003] The current restrictions on the use of halogen-containing flame retardants have prompted companies to develop halogen-free, recyclable and environmentally friendly materials. In addition, multi-layer composite technology balances performance and cost, replaces traditional metal shielding, and reduces wire harness weight and manufacturing costs.

[0004] Therefore, it is very necessary to propose a multi-layer composite shielded PVC wire harness tape and a preparation method thereof in this application to solve the problems mentioned above.

[0005] Patent document CN114822993B discloses a heat-resistant and aging-resistant automotive wiring harness and its preparation method. The above patent achieves a long service life of the wiring harness, and the overall strength of the wiring harness is high, and the flame retardancy and aging resistance are excellent, and it has high practicality.

[0006] In summary, the automotive wiring harness of the above-mentioned patent invention has excellent flame retardancy and aging resistance. On this basis, the research on PVC wiring harness tape was excavated. The existing PVC wiring harness tape uses a metal shielding layer, which greatly increases the cost, is bulky and brittle, and is not conducive to environmental protection. In addition, it is easy to cause damage during installation and use, which greatly reduces its original function. To this end, this application proposes a multi-layer composite shielding PVC wiring harness tape and its preparation method that can achieve efficient electromagnetic shielding through the vertical arrangement of MXene nanosheets combined with the interlacing of silver nanowires, while dynamically cross-linking the network through acylhydrazone bonds to maintain ultra-thin flexibility in extreme environments. Summary of the Invention

[0007] The purpose of the present invention is to provide a multi-layer composite shielded PVC wire harness tape and a preparation method thereof, so as to solve the technical problem raised in the above background technology that the traditional metal shielding not only has a heavy wire harness but also has a high manufacturing cost.

[0008] To achieve the above objectives, the present invention provides the following technical solutions: a multi-layer composite shielded PVC wiring harness tape, comprising a substrate layer, an adhesive layer, and a peeling layer, wherein a directional electromagnetic shielding layer is provided on the upper end of the substrate layer, and an aerogel buffer layer is provided on the upper end of the directional electromagnetic shielding layer; The directional electromagnetic shielding layer is composed of MXene nanosheets and silver nanowires in a mass ratio of 1:0.3 to 1:1, the MXene nanosheets are oriented and arranged perpendicular to the substrate layer, and the thickness of the directional electromagnetic shielding layer is 0.05 to 0.2 mm; The aerogel buffer layer is a composite of silicon dioxide aerogel and polyimide fibers interwoven together, and the polyimide fibers are interspersed into the aerogel pores in a three-dimensional network structure.

[0009] Preferably, a self-repairing reinforcement layer is provided on the upper end of the aerogel buffer layer, a photosensitive response layer is provided on the upper end of the self-repairing reinforcement layer, the photosensitive response layer serves as the outermost layer of the PVC wiring harness tape, and the peeling layer serves as the innermost layer of the PVC wiring harness tape; The self-repairing reinforcement layer is made of a polyurethane matrix cross-linked by dynamic acylhydrazone bonds and carbon nanotubes modified by borate. The mass ratio of the polyurethane matrix cross-linked by dynamic acylhydrazone bonds to the carbon nanotubes modified by borate is 100:8 to 100:12. The thickness of the self-repairing reinforcement layer is 0.1 to 0.3 mm. The photosensitive response layer is a photochromic coating containing spiropyran derivatives. The spiropyran molecules in the photochromic coating are covalently bonded to a polymethyl methacrylate matrix. The outer surface of the photosensitive response layer is provided with a periodic diamond microlens array by nanoimprinting. The microlens height is 5 to 30 μm and the microlens side length is 10 to 50 μm.

[0010] Preferably, a first interface layer is provided between the directional electromagnetic shielding layer and the substrate layer, the first interface layer is a polydopamine-modified carbon fiber woven mesh, the mesh density of the woven mesh is 80-120 meshes, the surface of the carbon fiber is loaded with zinc tin oxide nanoparticles, and the particle size of the zinc tin oxide nanoparticles is 20-80 nm; A second interface layer is provided between the aerogel buffer layer and the self-healing enhancement layer. The second interface layer is a polyvinylidene fluoride-acrylate copolymer film. The thickness of the second interface layer is 2 to 10 μm. The surface of the second interface layer is formed into a nano-columnar structure by plasma etching. The column height of the nano-columnar structure is 200 to 500 nm.

[0011] Preferably, the self-repairing reinforcement layer is embedded with a bionic honeycomb structure, which is composed of independent honeycomb units, with a honeycomb unit diameter of 0.2 to 0.8 mm, a honeycomb unit wall thickness of 10 to 50 μm, and a through hole with a diameter of 1 to 5 μm on the wall; The honeycomb structure is filled with thermo-induced phase change microcapsules. The shell of the thermo-induced phase change microcapsules is polyurea with a shell thickness of 0.5 to 2 μm. The core material of the thermo-induced phase change microcapsules is a mixture of paraffin wax and boron carbide, and the core material accounts for 60% to 80% of the mass.

[0012] Preferably, the mass fraction of the spiropyran derivative in the photosensitive response layer is 5% to 15%, the refractive index gradient of the microlens array is 1.4 to 1.8, the porosity of the aerogel pores is 85% to 95%, the pore diameter is 10 to 100 nm, and the density is 0.1 to 0.3 g / cm³; Conductive silver paste circuits are embedded at the bottom of the microlens array. The width of the conductive silver paste circuits is 10 to 50 μm, and the solid content of the silver paste is ≥85%. The conductive silver paste circuits are connected to the MXene nanosheets through silver nanoparticle solder joints. The conductive silver paste circuits are in contact with the MXene nanosheets to form electrical interconnection.

[0013] Preferably, the adhesive layer is made by mixing a fluorinated silicone acrylate pressure-sensitive adhesive and a dynamic disulfide bond cross-linking agent in a mass ratio of 100:2 to 100:6, and the cross-linking agent is a dithiodipropionate derivative; Liquid crystal molecules are dispersed in the adhesive layer. The liquid crystal molecules are 4-pentyl-4'-cyanobiphenyl. The mass fraction of the liquid crystal molecules in the adhesive layer accounts for 0.5% to 3%. The orientation direction of the liquid crystal molecules is parallel to the grating structure of the substrate layer.

[0014] Preferably, the surface of the liquid crystal molecules is coated with a graphene oxide thin layer, and the thickness of the graphene oxide thin layer is 1 to 3 nm; A third interface layer is provided between the adhesive layer and the self-healing reinforcement layer. The third interface layer is a polyacrylonitrile nanofiber membrane prepared by electrospinning. The fiber diameter of the polyacrylonitrile nanofiber membrane is 100-500nm, the porosity of the fiber membrane is 70%-90%, and the surface of the polyacrylonitrile nanofiber membrane is modified by an aminosilane coupling agent.

[0015] Preferably, the substrate layer is a co-extruded PVC / polycarbonate composite film, the mass proportion of polycarbonate is 15% to 30%, the thickness of the composite film is 0.08 to 0.4 mm, the surface of the composite film is processed by femtosecond laser to form a subwavelength grating structure, the peeling layer is a fluorinated release film, the surface of the fluorinated release film is coated with a perfluoropolyether release agent, and the release force of the perfluoropolyether release agent is 3 to 15 g / 25 mm; The grating period of the subwavelength grating structure is 300 to 800 nm, and the depth is 100 to 300 nm. An invisible QR code mark is printed on the back of the release film. The marked area is developed by ultraviolet-excited fluorescent ink, and the ink particle size is 0.1 to 1 μm.

[0016] Preferably, the preparation method comprises the following steps: S1. Processing the substrate layer: PVC and polycarbonate granules were blended and extruded in a twin-screw extruder with the barrel temperature set at 180-220°C and the die pressure at 8-12 MPa to form a composite film with a thickness of 0.08-0.4 mm. After femtosecond laser etching of subwavelength gratings, the composite film was sprayed with an ionic liquid interface agent, 1-ethyl-3-methylimidazolium tetrafluoroborate, and finally dried in a fluidized bed dryer at 60-80°C for 10-30 min. S2. Preparation of directional electromagnetic shielding layer: MXene nanosheets and silver nanowires are dispersed in a mixed solvent of N-methylpyrrolidone / ethylene glycol, where N-methylpyrrolidone and ethylene glycol are mixed in a volume ratio of 1:2, and the total mass of MXene nanosheets and silver nanowires accounts for 5% to 10%. The MXene nanosheets and silver nanowires are then electrophoretically deposited on a carbon fiber mesh with a magnetic field strength of 0.5 to 1.5 T and a deposition voltage of 50 to 100 V. The deposited carbon fiber mesh is annealed at 200 to 250°C in a nitrogen atmosphere for 1 to 2 hours. S3, forming an aerogel buffer layer: mixing and hydrolyzing ethyl orthosilicate, ethanol, and water in a molar ratio of 1:4:0.01, adding polyimide fibers, drying with supercritical carbon dioxide, and then immersing in a fluorinated silane solution to form a hydrophobic aerogel; S4. Construction of self-repairing reinforcement layer: dynamic acylhydrazone bond prepolymer, borate carbon nanotubes and phase change microcapsules are injected into a bionic honeycomb mold, and demolded after UV curing. The dynamic acylhydrazone bond prepolymer is prepared by condensation polymerization of glutaraldehyde and adipic acid dihydrazide; S5. Photoresponsive layer coating: Spiropyran derivatives and photoresist are mixed in a mass ratio of 1:9, spin-coated into a film, and then solidified by nanoimprinting template to form a microlens array. Finally, conductive silver paste circuits are screen-printed. S6. Adhesive layer lamination: Fluorosilicone acrylate pressure-sensitive adhesive and dynamic disulfide crosslinker are mixed, and then planetary stirring is used for degassing. Graphene oxide-coated liquid crystal molecules are added and dispersed by three-roll milling to a particle size of ≤100 nm. Finally, the mixture is coated on the nanofiber membrane and thermally cured at 45-65°C for 2-4 hours. S7. Full-layer integration of wire harness adhesive: The substrate layer, first interface layer, directional electromagnetic shielding layer, aerogel buffer layer, second interface layer, self-repairing reinforcement layer, third interface layer, adhesive layer and photosensitive response layer are stacked in sequence and vacuum hot-pressed at a pressure of 8-12 MPa and a temperature of 110-140°C. Finally, they are cut and the invisible QR code is etched using a laser.

[0017] Preferably, the preparation method further comprises the following steps: S21, the solvent for electrophoretic deposition is a mixture of N-methylpyrrolidone and ethylene glycol in a volume ratio of 1:2; S41, the bionic honeycomb mold was prepared by reactive ion etching combined with 3D printing technology, and the etching gas was a mixture of sulfur hexafluoride and oxygen with a flow ratio of 3:1; S51, nanoimprint template using electron beam lithography combined with nickel electroforming process.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. By adding a directional electromagnetic shielding layer, the present invention achieves directional arrangement in the direction perpendicular to the substrate layer and forms a highly conductive network, solving the problem of low shielding efficiency and large thickness caused by disordered distribution of electromagnetic shielding materials. The invention has a small thickness, lightweight and excellent shielding performance, making it suitable for wiring harness protection in confined spaces. 2. This invention achieves high cushioning and thermal insulation properties by embedding polyimide fibers into the pores of silica aerogel in a three-dimensional network structure. This solves the problem of poor thermal insulation and easy softening and failure of polyurethane foam in high-temperature environments, making it suitable for use in extreme environments and maintaining a certain degree of stability. 3. This invention constructs a self-repairing reinforcement layer, which allows the core material to be released at high temperatures to repair cracks. This solves the problem of direct discarding of the tape after mechanical damage, extends its service life, and reduces maintenance costs. 4. The present invention achieves low-impedance interconnection by combining a diamond-shaped microlens array with a bottom conductive silver paste circuit, solving the problems of slow response and poor electrical performance of existing materials, and is conducive to the coordinated regulation of environmental perception and electromagnetic shielding. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall structure of the multi-layer composite shielded PVC wiring harness tape of the present invention; Figure 2 Schematic diagram of the three-dimensional network structure of the aerogel buffer layer of the present invention; Figure 3 Schematic diagram of the process for preparing the adhesive tape of the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] For example 1, please refer to Figure 1 、 Figure 2 and Figure 3A multi-layer composite shielded PVC wiring harness tape comprises a substrate layer, an adhesive layer, and a peeling layer. A directional electromagnetic shielding layer is disposed on the upper end of the substrate layer, and an aerogel buffer layer is disposed on the upper end of the directional electromagnetic shielding layer. The directional electromagnetic shielding layer is composited with MXene nanosheets and silver nanowires in a mass ratio of 1:0.3 to 1:1. The MXene nanosheets are oriented and arranged perpendicular to the substrate layer. The thickness of the directional electromagnetic shielding layer is 0.05 to 0.2 mm. A self-repairing reinforcement layer is provided on the upper end of the aerogel buffer layer, a photosensitive response layer is provided on the upper end of the self-repairing reinforcement layer, the photosensitive response layer serves as the outermost layer of the PVC wiring harness tape, and the peeling layer serves as the innermost layer of the PVC wiring harness tape; Further, the substrate layer: PVC particles accounting for 85% by weight and polycarbonate particles accounting for 15% by weight were added to a twin-screw extruder and blended and extruded. The barrel temperature was 180°C in zone 1, 200°C in zone 2, 220°C at the die head, and the die head pressure was 10 MPa to prepare a PVC / polycarbonate composite film with a thickness of 0.2 mm. The surface of the film was etched by femtosecond laser to form a subwavelength grating structure with a period of 500 nm and a depth of 200 nm. The film was then sprayed with 5 g / m² of an ionic liquid interface agent, 1-ethyl-3-methylimidazolium tetrafluoroborate, and finally dried in a boiling dryer at 70°C for 20 minutes. Directed electromagnetic shielding layer: MXene nanosheets and silver nanowires are dispersed in a mixed solvent of N-methylpyrrolidone / ethylene glycol at a mass ratio of 1:0.5, with a total solid content of 8%. The mixture is electrophoretically deposited on the surface of a 100-mesh carbon fiber woven mesh and annealed in a nitrogen atmosphere at 230°C for 1.5 hours. Aerogel buffer layer: Ethyl orthosilicate, ethanol, and water are hydrolyzed at a molar ratio of 1:4:0.01, polyimide fibers are added, and after supercritical CO2 drying, they are impregnated with a fluorinated silane solution to form a hydrophobic aerogel with a porosity of 90% and a pore size of 50 nm. Self-healing reinforcement layer: A polyurethane matrix is ​​cross-linked with a dynamic acylhydrazone bond to form a hydrophobic aerogel with a porosity of 90% and a pore size of 50 nm. Acid-modified carbon nanotubes were mixed in a mass ratio of 100:10, injected into a biomimetic honeycomb mold, and demolded after UV curing. The photosensitive response layer was a mixture of spiropyran derivatives and polymethyl methacrylate, which was spin-coated into a film and then nano-imprinted with a diamond microlens array. A conductive silver paste circuit with a side length of 30μm, a height of 20μm, and a width of 30μm was connected to the MXene layer via screen printing. The adhesive layer was a mixture of fluorinated silicone acrylate pressure-sensitive adhesive and a dynamic disulfide bond crosslinker in a mass ratio of 100:4. Graphene oxide-coated 4-pentyl-4'-cyanobiphenyl was added and coated on a polyacrylonitrile nanofiber membrane. The layers of wiring harness tape are laminated in sequence using a vacuum hot press at a pressure of 10 MPa and a temperature of 125°C, and the invisible QR code is finally laser-etched.

[0022] For example 2, please refer to Figure 1 and Figure 3A multi-layer composite shielded PVC wiring harness tape, wherein the self-repairing reinforcement layer is made of a mixture of a polyurethane matrix cross-linked by dynamic acylhydrazone bonds and borate-modified carbon nanotubes, the mass ratio of the polyurethane matrix cross-linked by dynamic acylhydrazone bonds to the borate-modified carbon nanotubes being 100:8 to 100:12, and the thickness of the self-repairing reinforcement layer being 0.1 to 0.3 mm; The self-repairing reinforcement layer is embedded with a bionic honeycomb structure, which is composed of independent honeycomb units. The honeycomb unit has a diameter of 0.2 to 0.8 mm, a wall thickness of 10 to 50 μm, and a through hole with a diameter of 1 to 5 μm. The honeycomb structure is filled with thermo-induced phase change microcapsules. The shell of the thermo-induced phase change microcapsules is polyurea with a shell thickness of 0.5 to 2 μm. The core material of the thermo-induced phase change microcapsules is a mixture of paraffin wax and boron carbide, and the core material accounts for 60% to 80% by weight. The mass fraction of the spiropyran derivative in the photosensitive response layer is 5% to 15%, the refractive index gradient of the microlens array is 1.4 to 1.8, the porosity of the aerogel pores is 85% to 95%, the pore size is 10 to 100 nm, and the density is 0.1 to 0.3 g / cm³; a conductive silver paste circuit is embedded in the bottom of the microlens array, the conductive silver paste circuit has a width of 10 to 50 μm, and the silver paste solid content is ≥85%. The conductive silver paste circuit is connected to the MXene nanosheet via a silver nanoparticle solder joint, and the conductive silver paste circuit contacts the MXene nanosheet to form an electrical interconnection; Furthermore, a directional electromagnetic shielding layer was prepared: the mass ratio of MXene to silver nanowires was 1:1, the total solid content was 10%, and the annealing temperature was increased to 240°C; Preparation of photosensitive responsive layer: the side length of the microlens was reduced to 20 μm, and the content of spiropyran derivatives was increased to 12%; PVC particles accounting for 85% by mass and polycarbonate particles accounting for 15% by mass were added to a twin-screw extruder for blending and extrusion. The barrel temperature was 180°C in zone 1, 200°C in zone 2, 220°C at the die head, and the die head pressure was 10 MPa to prepare a PVC / polycarbonate composite film with a thickness of 0.2 mm. A subwavelength grating structure with a period of 500 nm and a depth of 200 nm was formed on the surface of the film by femtosecond laser etching. Then, 5 g / m² of ionic liquid interface agent 1-ethyl-3-methylimidazolium tetrafluoroborate was sprayed on the film, and finally dried in a boiling dryer at 70°C for 20 minutes. Ethyl orthosilicate, ethanol, and water were hydrolyzed in a molar ratio of 1:4:0.01, and polyimide fiber was added. After supercritical CO2 drying, it was immersed in a fluorinated silane solution to form a hydrophobic aerogel with a porosity of 90% and a pore size of 50 nm. The spiropyran derivative was mixed with polymethyl methacrylate and spin-coated into a film, and then a diamond microlens array was nano-imprinted. A conductive silver paste circuit with a side length of 30 μm, a height of 20 μm, and a width of 30 μm was connected to the MXene layer by screen printing. The fluorinated silicone acrylate pressure-sensitive adhesive was mixed with a dynamic disulfide bond cross-linker in a mass ratio of 100:4, and graphene oxide-coated 4-pentyl-4'-cyanobiphenyl was added and coated on the polyacrylonitrile nanofiber membrane; finally, the layers of the wiring harness tape were stacked in sequence under vacuum hot pressing at a pressure of 10 MPa and a temperature of 125°C, and the invisible QR code was finally laser-etched.

[0023] For example three, please refer to Figure 2 and Figure 3 A multi-layer composite shielded PVC wiring harness tape, wherein the adhesive layer is made of a mixture of a fluorinated silicone acrylate pressure-sensitive adhesive and a dynamic disulfide bond crosslinker in a mass ratio of 100:2 to 100:6, wherein the crosslinker is a dithiodipropionate derivative; liquid crystal molecules are dispersed in the adhesive layer, and the liquid crystal molecules are 4-pentyl-4'-cyanobiphenyl. The mass fraction of the liquid crystal molecules in the adhesive layer is 0.5% to 3%, and the orientation direction of the liquid crystal molecules is parallel to the grating structure of the substrate layer; The surface of the liquid crystal molecules is coated with a thin layer of graphene oxide, and the thickness of the graphene oxide thin layer is 1 to 3 nm. A third interface layer is provided between the adhesive layer and the self-repairing reinforcement layer. The third interface layer is a polyacrylonitrile nanofiber membrane prepared by electrospinning. The fiber diameter of the polyacrylonitrile nanofiber membrane is 100 to 500 nm, and the porosity of the fiber membrane is 70% to 90%. The surface of the polyacrylonitrile nanofiber membrane is modified by an aminosilane coupling agent. The substrate layer is a co-extruded PVC / polycarbonate composite film, the polycarbonate mass proportion is 15% to 30%, the composite film thickness is 0.08 to 0.4 mm, the surface of the composite film is formed with a subwavelength grating structure by femtosecond laser processing, the peeling layer is a fluorinated release film, the surface of the fluorinated release film is coated with a perfluoropolyether release agent, and the release force of the perfluoropolyether release agent is 3 to 15 g / 25 mm; the grating period of the subwavelength grating structure is 300 to 800 nm, and the depth is 100 to 300 nm. The back of the release film is printed with an invisible QR code mark, and the marked area is developed by ultraviolet excitation fluorescent ink, and the ink particle size is 0.1 to 1 μm; Furthermore, an aerogel buffer layer was prepared: the polyimide fiber content was increased to 8 wt%, the porosity was 95%, and the pore size was reduced to 30 nm; Preparation of self-repair reinforcement layer: honeycomb unit diameter 0.3mm, wall thickness 20μm, through-hole diameter 2μm; Substrate layer: PVC particles (85% by weight) and polycarbonate particles (15% by weight) were added to a twin-screw extruder and blended and extruded. The barrel temperature was 180°C in zone 1, 200°C in zone 2, and the die head was 220°C. The die head pressure was 10 MPa. A 0.2 mm thick PVC / polycarbonate composite film was prepared. The surface of the film was etched by femtosecond laser to form a subwavelength grating structure with a period of 500 nm and a depth of 200 nm. The film was then sprayed with 5 g / m² of the ionic liquid interface agent 1-ethyl-3-methylimidazolium tetrafluoroborate. Finally, the film was dried in a boiling dryer at 70°C for 20 minutes. Directed electromagnetic shielding layer: MXene nanosheets and silver nanowires were dispersed in a mixed solvent of N-methylpyrrolidone / ethylene glycol in a mass ratio of 1:0.5 with a total solid content of 8%, and electrophoretically deposited on the surface of a 100-mesh carbon fiber woven mesh, and annealed in a nitrogen atmosphere at 230°C for 1.5h; Photosensitive response layer: Spiropyran derivatives were mixed with polymethyl methacrylate, and after spin coating, a diamond microlens array was nanoimprinted. A conductive silver paste line with a side length of 30μm, a height of 20μm, and a width of 30μm was connected to the MXene layer by screen printing; Adhesive layer: Fluorosilicone acrylate pressure-sensitive adhesive and dynamic disulfide bond crosslinker were mixed in a mass ratio of 100:4, and graphene oxide-coated 4-pentyl-4'-cyanobiphenyl was added and coated on a polyacrylonitrile nanofiber membrane; The layers of the wiring harness tape were laminated in sequence by vacuum hot pressing at a pressure of 10MPa and a temperature of 125°C, and finally an invisible QR code was laser etched.

[0024] For example 4, please refer to Figure 1 、 Figure 2 and Figure 3A multi-layer composite shielded PVC wiring harness tape, wherein the aerogel buffer layer is a composite of silica aerogel and polyimide fibers interwoven together, with the polyimide fibers interpenetrating into the aerogel pores in a three-dimensional network structure; the photosensitive response layer is a photochromic coating containing spiropyran derivatives, wherein the spiropyran molecules in the photochromic coating are covalently linked to a polymethyl methacrylate matrix; and the outer surface of the photosensitive response layer is provided with a periodic diamond-shaped microlens array by nanoimprinting, with a microlens height of 5 to 30 μm and a microlens side length of 10 to 50 μm. A first interface layer is provided between the directional electromagnetic shielding layer and the substrate layer. The first interface layer is a polydopamine-modified carbon fiber woven mesh with a mesh density of 80 to 120 meshes. The carbon fiber surface is loaded with zinc tin oxide nanoparticles with a particle size of 20 to 80 nm. A second interface layer is provided between the aerogel buffer layer and the self-healing reinforcement layer. The second interface layer is a polyvinylidene fluoride-acrylate copolymer film with a thickness of 2 to 10 μm. The surface of the second interface layer is formed into a nano-columnar structure by plasma etching. The column height of the nano-columnar structure is 200 to 500 nm. Furthermore, the directional electromagnetic shielding layer: no magnetic field is applied, and the MXene nanosheets are randomly distributed; Substrate layer: PVC particles (85% by weight) and polycarbonate particles (15% by weight) were added to a twin-screw extruder and blended and extruded. The barrel temperature was 180°C in zone 1, 200°C in zone 2, and the die head was 220°C. The die head pressure was 10 MPa. A 0.2 mm thick PVC / polycarbonate composite film was prepared. The surface of the film was etched by femtosecond laser to form a subwavelength grating structure with a period of 500 nm and a depth of 200 nm. The film was then sprayed with 5 g / m² of the ionic liquid interface agent 1-ethyl-3-methylimidazolium tetrafluoroborate. Finally, the film was dried in a boiling dryer at 70°C for 20 minutes. Aerogel buffer layer: TEOS, ethanol, and water are hydrolyzed in a molar ratio of 1:4:0.01, polyimide fibers are added, and after supercritical CO2 drying, they are impregnated with a fluorinated silane solution to form a hydrophobic aerogel with a porosity of 90% and a pore size of 50 nm. Self-healing reinforcement layer: Dynamic acylhydrazone-crosslinked polyurethane matrix and borate-modified carbon nanotubes are mixed in a mass ratio of 100:10, injected into a biomimetic honeycomb mold, and demolded after UV curing. Photosensitive response layer: Spiropyran derivatives are mixed with polymethyl methacrylate and spin-coated into a film. After nanoimprinting the diamond microlens array, a conductive silver paste circuit with a side length of 30μm, a height of 20μm, and a width of 30μm was connected to the MXene layer by screen printing; the adhesive layer: a fluorinated silicone acrylate pressure-sensitive adhesive and a dynamic disulfide bond crosslinker were mixed in a mass ratio of 100:4, and 4-pentyl-4'-cyanobiphenyl coated with graphene oxide was added and coated on the polyacrylonitrile nanofiber membrane; the layers of the wiring harness tape were stacked in sequence by vacuum hot pressing at a pressure of 10MPa and a temperature of 125℃, and finally the invisible QR code was laser etched.

[0025] For example five, please refer to Figure 1 、 Figure 2 and Figure 3 , a multi-layer composite shielded PVC wire harness tape, the preparation method comprising the following steps: S1. Processing the substrate layer: PVC and polycarbonate granules were blended and extruded in a twin-screw extruder with the barrel temperature set at 180-220°C and the die pressure at 8-12 MPa to form a composite film with a thickness of 0.08-0.4 mm. After femtosecond laser etching of subwavelength gratings, the composite film was sprayed with an ionic liquid interface agent, 1-ethyl-3-methylimidazolium tetrafluoroborate, and finally dried in a fluidized bed dryer at 60-80°C for 10-30 min. S2. Preparation of directional electromagnetic shielding layer: MXene nanosheets and silver nanowires are dispersed in a mixed solvent of N-methylpyrrolidone / ethylene glycol, where N-methylpyrrolidone and ethylene glycol are mixed in a volume ratio of 1:2, and the total mass of MXene nanosheets and silver nanowires accounts for 5% to 10%. The MXene nanosheets and silver nanowires are then electrophoretically deposited on a carbon fiber mesh with a magnetic field strength of 0.5 to 1.5 T and a deposition voltage of 50 to 100 V. The deposited carbon fiber mesh is annealed at 200 to 250°C in a nitrogen atmosphere for 1 to 2 hours. S3, forming an aerogel buffer layer: mixing and hydrolyzing ethyl orthosilicate, ethanol, and water in a molar ratio of 1:4:0.01, adding polyimide fibers, drying with supercritical carbon dioxide, and then immersing in a fluorinated silane solution to form a hydrophobic aerogel; S4. Construction of self-repairing reinforcement layer: dynamic acylhydrazone bond prepolymer, borate carbon nanotubes and phase change microcapsules are injected into a bionic honeycomb mold, and demolded after UV curing. The dynamic acylhydrazone bond prepolymer is prepared by condensation polymerization of glutaraldehyde and adipic acid dihydrazide; S5. Photoresponsive layer coating: Spiropyran derivatives and photoresist are mixed in a mass ratio of 1:9, spin-coated into a film, and then solidified by nanoimprinting template to form a microlens array. Finally, conductive silver paste circuits are screen-printed. S6. Adhesive layer lamination: Fluorosilicone acrylate pressure-sensitive adhesive and dynamic disulfide crosslinker are mixed, and then planetary stirring is used for degassing. Graphene oxide-coated liquid crystal molecules are added and dispersed by three-roll milling to a particle size of ≤100 nm. Finally, the mixture is coated on the nanofiber membrane and thermally cured at 45-65°C for 2-4 hours. S7, full-layer integration of wire harness adhesive: The substrate layer, first interface layer, directional electromagnetic shielding layer, aerogel buffer layer, second interface layer, self-repairing reinforcement layer, third interface layer, adhesive layer and photosensitive response layer are stacked in order and vacuum hot pressed at a pressure of 8-12 MPa and a temperature of 110-140°C. Finally, the layers are cut and the invisible QR code is etched using a laser. The preparation method further comprises the following steps: S21, the solvent for electrophoretic deposition is a mixture of N-methylpyrrolidone and ethylene glycol in a volume ratio of 1:2; S41, the bionic honeycomb mold was prepared by reactive ion etching combined with 3D printing technology, and the etching gas was a mixture of sulfur hexafluoride and oxygen with a flow ratio of 3:1; S51, nanoimprint template using electron beam lithography combined with nickel electroforming process; Furthermore, a traditional PVC tape containing only a substrate layer and a common adhesive layer without shielding, buffering, or self-repairing functional layers was prepared as a control group. According to IEC62333-2, the frequency range is 1-10GHz, using a vector network analyzer to test the electromagnetic shielding effectiveness; According to GB / T1040-2006, tensile strength was tested at a rate of 50 mm / min. Flame retardancy test according to UL94 vertical burning test, record burning time and dripping; According to ASTMD638, 60℃ / 2h test scratch repair rate; According to ISO105-B02, the color difference ΔE value is measured after ultraviolet irradiation to test the light response; The test results are shown in Table 1 Performance Testing Example 1 Example 2 Example 3 Example 4 Example 5 (control) Shielding effectiveness dB 45 52 49 27 5 Tensile strength MPa 28.5 30.2 29.1 23.4 15.0 Flame retardant grade V-0 V-0 V-0 V-1 V-2 Self-repair rate% 92 95 94 none none ΔE value (UV irradiation) 35 42 38 - - Table 1 Working principle: First, the co-extruded PVC / polycarbonate composite film substrate layer is processed by femtosecond laser to form a subwavelength grating structure. MXene nanosheets and silver nanowires are compounded and oriented according to the mass ratio to form a directional electromagnetic shielding layer. Silica aerogel and polyimide fibers are interwoven to form an aerogel buffer layer. The self-healing reinforcement layer contains a polyurethane matrix cross-linked with dynamic acylhydrazone bonds, borate-modified carbon nanotubes, and embedded biomimetic honeycomb structures and thermoinduced phase change microcapsules. The photosensitive response layer contains a photochromic coating containing a spiropyran derivative, a nano-imprinted periodic diamond microlens array, and embedded conductive silver paste circuits, making the tape responsive to light. The adhesive layer is a mixture of fluorinated silicone acrylate pressure-sensitive adhesive and a dynamic disulfide bond crosslinker, with liquid crystal molecules dispersed in it, providing adhesion. Then, the interlayer bonding of the first to third interface layers is optimized, and finally, vacuum hot pressing is performed in the order of substrate layer, first interface layer, directional electromagnetic shielding layer, aerogel buffer layer, second interface layer, self-healing reinforcement layer, third interface layer, adhesive layer and photosensitive response layer.

[0026] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A multi-layer composite shielded PVC wire harness tape, characterized by: It includes a base material layer, an adhesive layer, and a peeling layer. A directional electromagnetic shielding layer is provided on the upper end of the base material layer, and an aerogel buffer layer is provided on the upper end of the directional electromagnetic shielding layer. The directional electromagnetic shielding layer is composed of MXene nanosheets and silver nanowires in a mass ratio of 1:0.3 to 1:1, the MXene nanosheets are oriented and arranged perpendicular to the substrate layer, and the thickness of the directional electromagnetic shielding layer is 0.05 to 0.2 mm; The aerogel buffer layer is a composite of silicon dioxide aerogel and polyimide fibers interwoven together, and the polyimide fibers are interspersed into the aerogel pores in a three-dimensional network structure.

2. The multi-layer composite shielded PVC wiring harness tape according to claim 1, characterized in that: A self-repairing reinforcement layer is provided on the upper end of the aerogel buffer layer, a photosensitive response layer is provided on the upper end of the self-repairing reinforcement layer, the photosensitive response layer serves as the outermost layer of the PVC wiring harness tape, and the peeling layer serves as the innermost layer of the PVC wiring harness tape; The self-repairing reinforcement layer is made of a polyurethane matrix cross-linked by dynamic acylhydrazone bonds and carbon nanotubes modified by borate. The mass ratio of the polyurethane matrix cross-linked by dynamic acylhydrazone bonds to the carbon nanotubes modified by borate is 100:8 to 100:

12. The thickness of the self-repairing reinforcement layer is 0.1 to 0.3 mm. The photosensitive response layer is a photochromic coating containing spiropyran derivatives. The spiropyran molecules in the photochromic coating are covalently bonded to a polymethyl methacrylate matrix. The outer surface of the photosensitive response layer is provided with a periodic diamond microlens array by nanoimprinting. The microlens height is 5 to 30 μm and the microlens side length is 10 to 50 μm.

3. The multi-layer composite shielded PVC wiring harness tape according to claim 1, characterized in that: A first interface layer is provided between the directional electromagnetic shielding layer and the substrate layer. The first interface layer is a polydopamine-modified carbon fiber woven mesh with a mesh density of 80 to 120 meshes. The surface of the carbon fiber is loaded with zinc tin oxide nanoparticles with a particle size of 20 to 80 nm. A second interface layer is provided between the aerogel buffer layer and the self-healing enhancement layer. The second interface layer is a polyvinylidene fluoride-acrylate copolymer film. The thickness of the second interface layer is 2 to 10 μm. The surface of the second interface layer is formed into a nano-columnar structure by plasma etching. The column height of the nano-columnar structure is 200 to 500 nm.

4. The multi-layer composite shielded PVC wiring harness tape according to claim 2, characterized in that: The self-repairing reinforcement layer is embedded with a bionic honeycomb structure, which is composed of independent honeycomb units. The honeycomb unit has a diameter of 0.2 to 0.8 mm, a wall thickness of 10 to 50 μm, and a through hole with a diameter of 1 to 5 μm. The honeycomb structure is filled with thermo-induced phase change microcapsules. The shell of the thermo-induced phase change microcapsules is polyurea with a shell thickness of 0.5 to 2 μm. The core material of the thermo-induced phase change microcapsules is a mixture of paraffin wax and boron carbide, and the core material accounts for 60% to 80% of the mass.

5. The multi-layer composite shielded PVC wire harness tape according to claim 2, characterized in that: The mass fraction of the spiropyran derivative in the photosensitive response layer is 5% to 15%, the refractive index gradient of the microlens array is 1.4 to 1.8, the porosity of the aerogel pores is 85% to 95%, the pore diameter is 10 to 100 nm, and the density is 0.1 to 0.3 g / cm³; Conductive silver paste circuits are embedded at the bottom of the microlens array. The width of the conductive silver paste circuits is 10 to 50 μm, and the solid content of the silver paste is ≥85%. The conductive silver paste circuits are connected to the MXene nanosheets through silver nanoparticle solder joints. The conductive silver paste circuits are in contact with the MXene nanosheets to form electrical interconnection.

6. The multi-layer composite shielded PVC wiring harness tape according to claim 1, characterized in that: The adhesive layer is made by mixing a fluorinated silicone acrylate pressure-sensitive adhesive and a dynamic disulfide bond cross-linking agent in a mass ratio of 100:2 to 100:6, wherein the cross-linking agent is a dithiodipropionate derivative; Liquid crystal molecules are dispersed in the adhesive layer. The liquid crystal molecules are 4-pentyl-4'-cyanobiphenyl. The mass fraction of the liquid crystal molecules in the adhesive layer accounts for 0.5% to 3%. The orientation direction of the liquid crystal molecules is parallel to the grating structure of the substrate layer.

7. The multi-layer composite shielded PVC wire harness tape according to claim 6, characterized in that: The surface of the liquid crystal molecules is coated with a thin layer of graphene oxide, and the thickness of the graphene oxide layer is 1 to 3 nm; A third interface layer is provided between the adhesive layer and the self-healing reinforcement layer. The third interface layer is a polyacrylonitrile nanofiber membrane prepared by electrospinning. The fiber diameter of the polyacrylonitrile nanofiber membrane is 100-500nm, the porosity of the fiber membrane is 70%-90%, and the surface of the polyacrylonitrile nanofiber membrane is modified by an aminosilane coupling agent.

8. The multi-layer composite shielded PVC wiring harness tape according to claim 1, characterized in that: The substrate layer is a co-extruded PVC / polycarbonate composite film, the polycarbonate mass proportion is 15% to 30%, the composite film thickness is 0.08 to 0.4 mm, the surface of the composite film is processed by femtosecond laser to form a subwavelength grating structure, the peeling layer is a fluorinated release film, the surface of the fluorinated release film is coated with a perfluoropolyether release agent, and the release force of the perfluoropolyether release agent is 3 to 15 g / 25 mm; The grating period of the subwavelength grating structure is 300 to 800 nm, and the depth is 100 to 300 nm. An invisible QR code mark is printed on the back of the release film. The marked area is developed by ultraviolet-excited fluorescent ink, and the ink particle size is 0.1 to 1 μm.

9. A method for preparing a multi-layer composite shielded PVC wiring harness tape, applicable to the multi-layer composite shielded PVC wiring harness tape according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: S1. Processing the substrate layer: PVC and polycarbonate granules were blended and extruded in a twin-screw extruder with the barrel temperature set at 180-220°C and the die pressure at 8-12 MPa to form a composite film with a thickness of 0.08-0.4 mm. After femtosecond laser etching of subwavelength gratings, the composite film was sprayed with an ionic liquid interface agent, 1-ethyl-3-methylimidazolium tetrafluoroborate, and finally dried in a fluidized bed dryer at 60-80°C for 10-30 min. S2. Preparation of directional electromagnetic shielding layer: MXene nanosheets and silver nanowires are dispersed in a mixed solvent of N-methylpyrrolidone / ethylene glycol, where N-methylpyrrolidone and ethylene glycol are mixed in a volume ratio of 1:2, and the total mass of MXene nanosheets and silver nanowires accounts for 5% to 10%. The MXene nanosheets and silver nanowires are then electrophoretically deposited on a carbon fiber mesh with a magnetic field strength of 0.5 to 1.5 T and a deposition voltage of 50 to 100 V. The deposited carbon fiber mesh is annealed at 200 to 250°C in a nitrogen atmosphere for 1 to 2 hours. S3, forming an aerogel buffer layer: mixing and hydrolyzing ethyl orthosilicate, ethanol, and water in a molar ratio of 1:4:0.01, adding polyimide fibers, drying with supercritical carbon dioxide, and then immersing in a fluorinated silane solution to form a hydrophobic aerogel; S4. Construction of self-repairing reinforcement layer: dynamic acylhydrazone bond prepolymer, borate carbon nanotubes and phase change microcapsules are injected into a bionic honeycomb mold, and demolded after UV curing. The dynamic acylhydrazone bond prepolymer is prepared by condensation polymerization of glutaraldehyde and adipic acid dihydrazide; S5. Photoresponsive layer coating: Spiropyran derivatives and photoresist are mixed in a mass ratio of 1:9, spin-coated into a film, and then solidified by nanoimprinting template to form a microlens array. Finally, conductive silver paste circuits are screen-printed. S6. Adhesive layer lamination: Fluorosilicone acrylate pressure-sensitive adhesive and dynamic disulfide crosslinker are mixed, and then planetary stirring is used for degassing. Graphene oxide-coated liquid crystal molecules are added and dispersed by three-roll milling to a particle size of ≤100 nm. Finally, the mixture is coated on the nanofiber membrane and thermally cured at 45-65°C for 2-4 hours. S7. Full-layer integration of wire harness adhesive: The substrate layer, first interface layer, directional electromagnetic shielding layer, aerogel buffer layer, second interface layer, self-repairing reinforcement layer, third interface layer, adhesive layer and photosensitive response layer are stacked in sequence and vacuum hot-pressed at a pressure of 8-12 MPa and a temperature of 110-140°C. Finally, they are cut and the invisible QR code is etched using a laser.

10. The method for preparing a multi-layer composite shielded PVC wiring harness tape according to claim 9, characterized in that: The preparation method further comprises the following steps: S21, the solvent for electrophoretic deposition is a mixture of N-methylpyrrolidone and ethylene glycol in a volume ratio of 1:2; S41, the bionic honeycomb mold was prepared by reactive ion etching combined with 3D printing technology, and the etching gas was a mixture of sulfur hexafluoride and oxygen with a flow ratio of 3:1; S51, nanoimprint template using electron beam lithography combined with nickel electroforming process.

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