A flexible and stretchable shielded wire and its preparation method

Abstract

The present invention discloses a flexible and stretchable shielding wire, which sequentially includes a flexible conductive layer, a flexible inner insulating layer, a flexible shielding layer and a flexible outer insulating layer from inside to outside. The flexible shielding layer includes: 1-20% of a first conductive component; 6-15% of a second conductive component; and 65-93% of a resin, by mass percentage. The flexible and stretchable shielding wire of the present invention can improve the anti-electromagnetic interference ability, has flexible and stretchable properties, and can be applied in the field of flexible electronics.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible wires, and particularly relates to a flexible and stretchable shielded wire. In particular, the present invention also relates to a method for preparing the flexible and stretchable shielded wire. Background Art

[0002] A wire with a conductor wrapped outside is called a shielded wire, and the wrapped conductor is called a shielding layer. By grounding, the interference signal is introduced into the ground, which can prevent the interference signal from entering the inner conductor and reduce the loss of the transmitted signal at the same time. Traditional shielded wires use copper braiding, copper foil or aluminum foil as the shielding layer. The processing cost of copper braiding is high and the production speed is slow; the bending strength of copper foil or aluminum foil is poor, and it is easy to break when bent repeatedly or there is vibration or friction, resulting in signal attenuation.

[0003] In high-speed system design, integrated circuit pins, high-frequency signal lines and various connectors are common radiation interference sources in flexible printed electronics design. The electromagnetic waves they emit are electromagnetic interference, which will affect the normal operation of themselves and other systems. For example, when transmitting high voltage in flexible electronic devices, high-frequency crosstalk will occur. Therefore, there is an urgent need to develop a flexible and stretchable shielded wire. Summary of the Invention

[0004] The present invention is made based on the inventor's discovery and recognition of the following facts and problems:

[0005] In order to improve the anti-interference ability of electronic devices such as electronics, telecommunications, and power, a shielding layer is usually used in shielded wires to improve electromagnetic interference resistance and prevent signal loss inside the cable and external signal interference. In related technologies, shielding is mainly carried out through metal shielding layers such as copper meshes and copper foils. However, due to the poor bending resistance of metals, the shielding layer is prone to breakage and failure during long-term use. And existing flexible and stretchable wires generally only have a conductive inner core and an insulating outer shell, and do not have shielding performance.

[0006] The present invention aims to solve at least one of the technical problems in the related technologies to a certain extent.

[0007] Therefore, an embodiment of the present invention provides a flexible and stretchable shielded wire, which can improve the electromagnetic interference resistance ability, has flexible and stretchable performance, and can be applied in the field of flexible electronics.

[0008] The flexible and stretchable shielded wire according to the first aspect embodiment of the present invention sequentially includes a flexible conductive layer, a flexible inner insulating layer, a flexible shielding layer and a flexible outer insulating layer from the inside to the outside. The flexible shielding layer includes:

[0009] 1-20% of a first conductive component;

[0010] 6-15% of a second conductive component; and

[0011] 65 - 93% resin;

[0012] By mass percentage.

[0013] Advantages and technical effects brought by the independent claims of the flexible stretchable shielded wire according to the first aspect embodiment of the present invention: 1. In the embodiment of the present invention, a flexible shielding layer is introduced into the flexible stretchable wire, improving the electromagnetic interference resistance. The conductive layer, shielding layer, and insulating layer all adopt flexible stretchable materials, making the finally obtained shielded wire have flexible stretchable performance, with good shielding effect and conductivity; 2. In the embodiment of the present invention, the second conductive component in the shielding layer provides the main conductive function to ensure the shielding performance. By adding the first conductive component, the conductive connection between the second conductive components is improved, increasing the conductive path and improving the conductivity, and can form multiple reflections of electromagnetic waves, causing additional losses to the electromagnetic waves and improving the shielding performance; 3. In the embodiment of the present invention, the resin in the shielding layer plays a bonding role to ensure the film-forming property of the shielding layer; 4. The shielding effectiveness of the flexible stretchable shielded wire in the embodiment of the present invention is 60 - 80 db, and it can be stretched by 200 - 260%; 5. The flexible stretchable shielded wire in the embodiment of the present invention can be applied to radio transmission equipment, audio equipment, network transmission equipment, etc., can work normally in a relatively harsh electromagnetic environment, and itself will not radiate excessive electromagnetic waves to interfere with the normal operation of other surrounding devices and networks.

[0014] For the flexible stretchable shielded wire according to the first aspect embodiment of the present invention, wherein the first conductive component includes at least one of graphene, carbon nanotubes, or aluminum titanium carbide; and / or, the second conductive component includes at least one of silver nanowires, silver nanoparticles, nickel nanoparticles, copper nanowires, copper nanoparticles, gold nanowires, or gold nanoparticles; and / or, the resin includes at least one of cellulose derivatives, waterborne polyurethane, or waterborne polyacrylate resin.

[0015] For the flexible stretchable shielded wire according to the first aspect embodiment of the present invention, wherein the flexible conductive layer includes 0 - 10% liquid metal, 8 - 30% nano-conductive material, and 60 - 92% resin, by mass percentage.

[0016] For the flexible stretchable shielded wire according to the first aspect embodiment of the present invention, wherein the liquid metal includes at least one of gallium indium alloy, gallium tin indium alloy, gallium aluminum alloy, or gallium bismuth alloy, with a content of 2 - 10%; and / or, the nano-conductive material includes at least one of silver nanowires, silver nanoparticles, copper nanowires, copper nanoparticles, gold nanowires, gold nanoparticles, carbon nanotubes, or graphene; and / or, the resin includes at least one of cellulose derivatives, waterborne polyurethane, or waterborne polyacrylate resin.

[0017] A flexible and stretchable shielded wire according to an embodiment of the first aspect of the present invention, wherein the cellulose derivative is hydroxypropyl methylcellulose, hydroxyethyl cellulose or carboxymethyl cellulose.

[0018] A flexible and stretchable shielded wire according to an embodiment of the first aspect of the present invention, wherein the flexible inner insulating layer or outer insulating layer comprises at least one of thermoplastic polyurethane, polydimethylsiloxane, acrylic resin or epoxy resin.

[0019] An embodiment of the second aspect of the present invention provides a method for preparing a flexible and stretchable shielded wire, comprising the following steps:

[0020] a. Place the flexible conductive layer material into a first mold, heat and cure it into a shape, and then remove the first mold to obtain a formed flexible conductive layer.

[0021] b. Place the formed flexible conductive layer obtained in step a at the central position of a second mold, place the flexible inner insulating layer material into the second mold, heat and cure it into a shape, and then remove the second mold to obtain a flexible conductive layer with a formed flexible inner insulating layer coated on the outside.

[0022] c. Place at least one strand of the formed flexible conductive layer with a formed flexible inner insulating layer coated on the outside obtained in step b at the central position of a third mold, place the flexible shielding layer material into the third mold, heat and cure it into a shape, and then remove the third mold to obtain a formed flexible conductive layer with a flexible inner insulating layer and a flexible shielding layer coated thereon from the inside to the outside in sequence.

[0023] d. Place the formed flexible conductive layer with a flexible inner insulating layer and a flexible shielding layer coated thereon from the inside to the outside obtained in step c at the central position of a fourth mold, place the flexible outer insulating layer material into the fourth mold, heat and cure it into a shape, and then remove the fourth mold to obtain a formed flexible and stretchable shielded wire.

[0024] Advantages and technical effects brought by the independent claims of the embodiment of the second aspect of the present invention: In the embodiment of the present invention, a flexible and stretchable shielded wire is prepared by a mold forming method, which can prepare single-strand wires and can also prepare multi-strand wires according to needs. The preparation method is simple, easy to apply, and the obtained wire has excellent shielding performance and stretching performance.

[0025] For the method for preparing a flexible and stretchable shielded wire according to an embodiment of the second aspect of the present invention, wherein in step a, b, c or d, the temperature for curing and forming is 60 - 120 °C, and the curing time is 10 - 90 minutes.

[0026] An embodiment of the third aspect of the present invention provides a method for preparing a flexible and stretchable shielded wire, comprising the following steps:

[0027] a. Take the materials of the flexible conductive layer, flexible inner insulating layer, flexible shielding layer and flexible outer insulating layer in the designed proportion. The flexible conductive layer includes 0-20% liquid metal, 10-40% nano conductive material, 30-87% resin and 3-10% crosslinking agent; and / or, the flexible inner insulating layer includes 90-97% resin and 3-10% crosslinking agent, by mass percentage. Among them, the liquid metal includes at least one of gallium indium alloy, gallium tin indium alloy, gallium aluminum alloy or gallium bismuth alloy; and / or, the nano conductive material includes at least one of silver nanowire, silver nanoparticle, copper nanowire, copper nanoparticle, gold nanowire, gold nanoparticle, carbon nanotube or graphene; and / or, the resin includes at least one of hydroxyl-terminated polydimethylsiloxane, hydroxyl-modified polyurethane or natural rubber; and / or, the crosslinking agent includes boric acid or phenylboric acid; and / or, the flexible shielding layer is the shielding layer of the flexible stretchable shielding wire in the first aspect embodiment of the present invention; and / or, the flexible outer insulating layer includes at least one of thermoplastic polyurethane, polydimethylsiloxane, acrylic resin or epoxy resin;

[0028] b. Load the flexible conductive layer and the flexible inner insulating layer materials described in step a into syringes respectively, and perform coaxial printing to obtain a formed flexible conductive layer with a flexible inner insulating layer coated on the outside;

[0029] c. Place at least one formed flexible conductive layer with a flexible inner insulating layer coated on the outside obtained in step b at the central position of the first mold, place the flexible shielding layer in the first mold, heat and cure it to form, and then remove the first mold to obtain a formed flexible conductive layer with a flexible inner insulating layer and a flexible shielding layer coated in sequence from the inside to the outside;

[0030] d. Place the formed flexible conductive layer with a flexible inner insulating layer and a flexible shielding layer coated in sequence from the inside to the outside obtained in step c at the central position of the second mold, place the flexible outer insulating layer in the second mold, heat and cure it to form, and then remove the second mold to obtain a formed flexible stretchable shielding wire.

[0031] Advantages and technical effects brought by the independent claims of the third aspect embodiment of the present invention: In the embodiment of the present invention, a flexible stretchable shielding wire is prepared by combining mold forming and coaxial printing. It can prepare single-strand wires and can also prepare multi-strand wires according to needs. The preparation method is simple, easy to apply, and the prepared wire has excellent shielding performance and tensile performance.

[0032] The preparation method of the flexible and stretchable shielding wire according to the embodiment of the third aspect of the present invention, wherein, in the step b, the flexible conductive layer and the flexible inner insulating layer material described in the step a are respectively heated to 160 - 190 °C, maintained for 1 - 3 hours, then cooled to room temperature, and respectively loaded into syringes for coaxial printing, with a printing speed of 0.5 - 100 mm / s and a printing air pressure of 5 - 90 psi; and / or, in the step c or d, the curing and forming temperature is 60 - 120 °C, and the curing time is 10 - 90 minutes. Brief Description of the Drawings

[0033] Figure 1 is a schematic structural diagram of the mold used in Embodiment 1 of the present invention;

[0034] Figure 2 is a schematic structural diagram of the flexible and stretchable shielding wire obtained in Embodiment 1 of the present invention;

[0035] Figure 3 is a schematic structural diagram of the flexible and stretchable shielding wire obtained in Embodiment 2 of the present invention;

[0036] Figure 4 is a schematic structural diagram of the coaxial printing system in Embodiment 6 of the present invention;

[0037] Figure 5 is a schematic structural diagram of the coaxial printing needle head and the printed wire structure in Embodiment 6 of the present invention. Detailed Description of the Embodiments

[0038] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0039] The flexible and stretchable shielding wire according to the embodiment of the first aspect of the present invention includes, from the inside to the outside, a flexible conductive layer, a flexible inner insulating layer, a flexible shielding layer, and a flexible outer insulating layer. The flexible shielding layer includes:

[0040] 1 - 20% of a first conductive component;

[0041] 6 - 15% of a second conductive component; and

[0042] 65 - 93% of a resin;

[0043] Calculated by mass percentage.

[0044] There is no particular limitation on the flexible conductive layer, the flexible inner insulating layer, and the flexible outer insulating layer in the flexible and stretchable shielding wire of the embodiment of the present invention, and any material that can endow the wire with flexible characteristics can be used.

[0045] Advantages and technical effects brought by the independent claims according to the embodiments of the first aspect of the present invention: 1. In the embodiments of the present invention, a flexible shielding layer is introduced into the flexible and stretchable wire, improving the anti-electromagnetic interference ability. The conductive layer, shielding layer, and insulating layer all adopt flexible and stretchable materials, making the finally obtained shielding wire have flexible and stretchable properties, with good shielding effect and conductivity; 2. In the embodiments of the present invention, the second conductive component in the shielding layer provides the main conductive function to ensure the shielding performance. By adding the first conductive component, the conductive connection between the second conductive components is improved, increasing the conductive path and improving the conductivity. Moreover, multiple reflections of electromagnetic waves can be formed, causing additional losses to the electromagnetic waves and improving the shielding performance; 3. In the embodiments of the present invention, the resin in the shielding layer plays a bonding role to ensure the film-forming property of the shielding layer; 4. The shielding effectiveness of the flexible and stretchable shielding wire in the embodiments of the present invention is 60 - 80 dB, and it can be stretched by 200 - 260%; 5. The flexible and stretchable shielding wire in the embodiments of the present invention can be applied to radio transmission devices, audio devices, network transmission devices, etc. It can work normally in a relatively harsh electromagnetic environment and will not radiate excessive electromagnetic waves to interfere with the normal operation of other surrounding devices and networks.

[0046] The flexible and stretchable shielding wire according to the embodiments of the first aspect of the present invention, wherein the first conductive component includes at least one of graphene, carbon nanotubes, or aluminum titanium carbide; the second conductive component includes at least one of silver nanowires, silver nanoparticles, nickel nanoparticles, copper nanowires, copper nanoparticles, gold nanowires, or gold nanoparticles; the resin includes at least one of cellulose derivatives, waterborne polyurethanes, or waterborne polyacrylic resins.

[0047] A flexible and stretchable shielded wire according to an embodiment of the first aspect of the present invention, wherein the flexible conductive layer comprises 0-10% of liquid metal, 8-30% of nano conductive material, and 60-92% of resin, by mass percentage. Preferably, the liquid metal comprises at least one of gallium indium alloy, gallium tin indium alloy, gallium aluminum alloy or gallium bismuth alloy, and the content of liquid metal in the flexible conductive layer is 2-10%; the nano conductive material comprises at least one of silver nanowires, silver nanoparticles, copper nanowires, copper nanoparticles, gold nanowires, gold nanoparticles, carbon nanotubes or graphene; the resin comprises at least one of cellulose derivatives, waterborne polyurethane or waterborne polyacrylic resin. Preferably, the cellulose derivative is hydroxypropyl methyl cellulose, hydroxyethyl cellulose or carboxymethyl cellulose. The materials selected for the flexible conductive layer in the embodiments of the present invention have excellent electrical conductivity. The liquid metal is in a liquid state and still has good electrical conductivity during the stretching process; the metal nano materials or conductive carbon materials form good conductive paths through the conductive percolation network. Although the metal nano materials have slippage during the stretching process, due to the fact that the liquid metal plays a role of conductive bridging at the joints of the nano materials, the overall electrical conductivity of the conductive percolation network is still good.

[0048] A flexible and stretchable shielded wire according to an embodiment of the first aspect of the present invention, wherein the flexible inner insulating layer or the outer insulating layer comprises at least one of thermoplastic polyurethane, polydimethylsiloxane, acrylic resin or epoxy resin.

[0049] An embodiment of the second aspect of the present invention provides a method for preparing a flexible and stretchable shielded wire, comprising the following steps:

[0050] a. According to the formulations of the flexible conductive layer, flexible inner insulating layer, flexible shielding layer and flexible outer insulating layer of the flexible and stretchable shielded wire according to the embodiment of the first aspect of the present invention, take the materials of the flexible conductive layer, flexible inner insulating layer, flexible shielding layer and flexible outer insulating layer in the designed proportions, and respectively add solvents to stir and mix each layer; preferably, the solvent used for the flexible conductive layer is water, ethylene glycol, ethanol or N,N-dimethylformamide, and the addition amount is 6-50 times the weight of the resin in the conductive layer; the solvent used for the flexible shielding layer is water, ethylene glycol, ethanol or N,N-dimethylformamide, and the addition amount is 4-50 times the weight of the resin in the shielding layer; the solvents used for the flexible inner insulating layer and the outer insulating layer are N,N-dimethylformamide, binary ester or ethylene glycol, and the addition amount is 1-5 times the weight of the resin in the inner insulating layer or the outer insulating layer;

[0051] b. Put the mixed flexible conductive layer material into a first mold, heat and cure it to form a shape, and then remove the first mold. Preferably, the curing temperature is 60-120°C and the curing time is 10-90 minutes to obtain a formed flexible conductive layer;

[0052] c. Place the formed flexible conductive layer obtained in step b at the center position of the second mold. Put the mixed flexible inner insulating layer material into the second mold. After heating and curing to form, remove the second mold. Preferably, the curing temperature is 60 - 120 °C and the curing time is 10 - 90 minutes to obtain a flexible conductive layer with a flexible inner insulating layer coated on the outside;

[0053] d. Place at least one strand of the formed flexible conductive layer with a flexible inner insulating layer coated on the outside obtained in step c at the center position of the third mold. Put the mixed flexible shielding layer material into the third mold. After heating and curing to form, remove the third mold. Preferably, the curing temperature is 60 - 120 °C and the curing time is 10 - 90 minutes to obtain a flexible conductive layer with a flexible inner insulating layer and a flexible shielding layer coated from the inside to the outside;

[0054] e. Place the formed flexible conductive layer with a flexible inner insulating layer and a flexible shielding layer coated from the inside to the outside obtained in step d at the center position of the fourth mold. Put the mixed flexible outer insulating layer material into the fourth mold. After heating and curing to form, remove the fourth mold. Preferably, the curing temperature is 60 - 120 °C and the curing time is 10 - 90 minutes to obtain a formed flexible stretchable shielded wire.

[0055] Advantages and technical effects brought by the independent claims of the second aspect embodiment of the present invention: In the embodiment of the present invention, a flexible stretchable shielded wire is prepared by a mold forming method, which can prepare single-strand wires, and can also prepare multi-strand wires such as two-strand, three-strand, four-strand, five-strand... according to needs. The preparation method is simple, easy to apply, and the prepared wire has excellent shielding performance and stretching performance.

[0056] The third aspect embodiment of the present invention provides a method for preparing a flexible stretchable shielded wire, including the following steps:

[0057] a. Take the flexible conductive layer, flexible inner insulating layer, flexible shielding layer, and flexible outer insulating layer with the designed ratios, and stir and mix them evenly respectively. The flexible conductive layer includes 0 - 20% liquid metal, 10 - 40% nano conductive material, 30 - 87% resin, and 3 - 10% crosslinking agent; the flexible inner insulating layer includes 90 - 97% resin and 3 - 10% crosslinking agent, by mass percentage. Among them, the liquid metal includes at least one of gallium indium alloy, gallium tin indium alloy, gallium aluminum alloy, or gallium bismuth alloy; the nano conductive material includes at least one of silver nanowires, silver nanoparticles, copper nanowires, copper nanoparticles, gold nanowires, gold nanoparticles, carbon nanotubes, or graphene; the resin includes at least one of hydroxyl-terminated polydimethylsiloxane, hydroxyl-modified polyurethane, or natural rubber, and the crosslinking agent includes at least one of boric acid or phenylboric acid. The flexible shielding layer is the shielding layer of the flexible stretchable shielding wire in the first aspect embodiment of the present invention; the flexible outer insulating layer includes at least one of thermoplastic polyurethane, polydimethylsiloxane, acrylic resin, or epoxy resin;

[0058] b. Heat the flexible conductive layer and the flexible inner insulating layer materials in step a to 160 - 190 °C respectively, keep for 1 - 3 hours, then cool to room temperature, load them into syringes respectively, and perform coaxial printing to obtain a formed flexible conductive layer with a flexible inner insulating layer coated on the outside. Preferably, the printing speed is 0.5 - 100 mm / s, and the printing air pressure is 5 - 90 psi;

[0059] c. Place at least one strand of the formed flexible conductive layer with a flexible inner insulating layer coated on the outside obtained in step b at the center position of the first mold. Add the flexible shielding layer after mixing with a solvent and place it in the first mold. After heating and curing and forming, remove the first mold. Preferably, the curing and forming temperature is 60 - 120 °C, and the curing time is 10 - 90 minutes to obtain a formed flexible conductive layer with a flexible inner insulating layer and a flexible shielding layer coated in sequence from the inside to the outside. Preferably, the solvent used for the flexible shielding layer is water, ethylene glycol, ethanol, or N,N-dimethylformamide, and the addition amount is 4 - 50 times the weight of the resin such as cellulose derivative, waterborne polyurethane, or waterborne polyacrylate resin in the shielding layer;

[0060] d. Place the formed flexible conductive layer coated with a flexible inner insulating layer and a flexible shielding layer from the inside out in the center of the second mold. Add the flexible outer insulating layer after mixing it with a solvent and place it in the second mold. Preferably, the curing temperature is 60 - 120 °C and the curing time is 10 - 90 minutes to obtain a formed flexible stretchable shielded wire. Preferably, the solvent used for the flexible outer insulating layer is N,N-dimethylformamide, binary ester or ethylene glycol, and the addition amount is 1 - 5 times the weight of the outer insulating layer resin such as thermoplastic polyurethane, polydimethylsiloxane, acrylic resin or epoxy resin.

[0061] Advantages and technical effects brought by the independent claims of the third aspect embodiment of the present invention: In the embodiments of the present invention, a flexible stretchable shielded wire is prepared by combining mold forming and coaxial printing. It can prepare single-strand wires, and can also prepare multi-strand wires such as two-strand, three-strand, four-strand, five-strand... according to needs. The preparation method is simple and easy to apply, and the prepared wire has excellent shielding performance and stretching performance. In the embodiments of the present invention, a cross-linking agent boric acid or phenylboric acid is added to the conductive layer and the inner insulating layer. During the stretching process, micro-cracks can self-heal, ensuring that the conductivity of the conductive layer and the insulation performance of the insulating layer can always be in a good state.

[0062] By using the preparation methods of the embodiments of the present invention, flexible stretchable shielded wires can be finally obtained. Among them, the diameter of the conductive layer is 2 - 10 mm, the thickness of the inner insulating layer is 0.2 - 2 mm, the thickness of the shielding layer is 0.1 - 1 mm, and the thickness of the outer insulating layer is 0.5 - 5 mm.

[0063] In the embodiments of the present invention, the coaxial printing and mold forming methods can be combined. Among the four layers from the inside out, the conductive layer can also be selected for printing, and the remaining layers are formed by mold forming to obtain a flexible stretchable shielded wire.

[0064] The raw materials used in the embodiments of the present invention can all be obtained by purchasing in the market.

[0065] Example 1 prepares a flexible stretchable shielded wire by using the mold forming method

[0066] Prepare the conductive layer: Prepare the conductive layer according to the formula of 5 wt% gallium-indium alloy, 10 wt% silver nanowires and 85 wt% hydroxypropyl methylcellulose. Add water with a weight 20 times that of hydroxypropyl methylcellulose as a solvent. Weigh each material, and mix them evenly by mechanical stirring for later use;

[0067] Prepare the inner insulating layer: The inner insulating layer is polydimethylsiloxane. The added solvent is N,N-dimethyl, and the addition amount of the solvent is 2 times the weight of polydimethylsiloxane. Mix them evenly by mechanical stirring for later use;

[0068] Prepare the shielding layer: Prepare the shielding layer according to the formula of 4 wt% carbon nanotubes, 8 wt% nickel nanoparticles and 88 wt% waterborne acrylic resin. Add water with a weight 30 times that of the waterborne acrylic resin as a solvent. Weigh each material, mix them evenly by mechanical stirring, and set aside for later use;

[0069] Prepare the outer insulating layer: The outer insulating layer is polydimethylsiloxane. The added solvent is N,N-dimethyl. The amount of solvent added is 1 time the weight of the polydimethylsiloxane. Weigh each material, mix them evenly by mechanical stirring, and set aside for later use;

[0070] As Figure 1 shown, the mold used in the mold forming method is for injecting wire materials, and the mold has a cylindrical cavity inside. Preferably, the mold is composed of sub-molds A and B with the same structure. Both sub-molds A and B are long modules provided with semi-circular grooves. After combining the grooved sides of sub-mold A and sub-mold B, a mold with a cylindrical cavity inside is formed. The mold is divided into two identical parts. On the one hand, the production cost of the mold is low, and on the other hand, it is convenient for the assembly and disassembly of the mold.

[0071] In this embodiment, the first mold, the second mold, the third mold, and the fourth mold are used to prepare the flexible conductive layer, the flexible inner insulating layer, the flexible shielding layer, and the flexible outer insulating layer in sequence. Among them, the radii of the cylindrical cavities of the first mold, the second mold, the third mold, and the fourth mold increase in sequence.

[0072] Put the evenly mixed flexible conductive layer material into the first mold, heat it at 80 °C for 20 minutes for curing and forming, then remove the first mold to obtain the formed conductive layer; put the formed conductive layer at the center position of the second mold, and then put the evenly mixed flexible inner insulating layer material into the second mold, heat it at 90 °C for 10 minutes for curing and forming, then remove the second mold to obtain the formed flexible conductive layer with an inner insulating layer coated on the outside; put the flexible conductive layer with a flexible inner insulating layer coated on the outside at the center position of the third mold, put the evenly mixed shielding layer material into the third mold, heat it at 85 °C for 15 minutes for curing and forming, then remove the third mold to obtain the formed flexible conductive layer with a flexible inner insulating layer and a flexible shielding layer coated from the inside to the outside; put the flexible conductive layer with a flexible inner insulating layer and a flexible shielding layer coated from the inside to the outside at the center position of the fourth mold, put the evenly mixed flexible outer insulating layer material into the fourth mold, heat it at 110 °C for 10 minutes for curing and forming, then remove the fourth mold to obtain the formed flexible stretchable shielded wire, where the flexible conductive layer of the flexible stretchable shielded wire is coated with a flexible inner insulating layer, a flexible shielding layer, and a flexible outer insulating layer from the inside to the outside.

[0073] The structure of the flexible stretchable shielded wire prepared by the method of Example 1 can be referred to Figure 2, the diameter of the conductive layer of the flexible and stretchable shielded wire prepared in this embodiment is 5 mm, the thickness of the inner insulating layer is 0.4 mm, the thickness of the shielding layer is 0.3 mm, the thickness of the outer insulating layer is 3.5 mm, the shielding effectiveness of the wire is 70 db, it can be stretched by 240% along the wire length direction, the resistance per unit length of the wire is 0.7 Ω / m, when the stretching rate of the wire is 80% of the elongation at break, the resistance per unit length of the wire is 0.82 Ω / m, and the shielding effectiveness of the wire is 58 db.

[0074] In Example 2, a flexible and stretchable shielded wire was prepared by a die forming method.

[0075] The method is the same as that of Example 1, except that the flexible conductive layer with a flexible inner insulating layer wrapped on the outside of the multi-strand formed is placed at the center position of the second die, and the uniformly mixed flexible shielding layer material is put into the die. After curing and forming by heating at 85 °C for 15 minutes, the die is removed to obtain a formed flexible conductive layer sequentially wrapped with a flexible shielding layer and a flexible inner insulating layer from the inside to the outside. In this embodiment, the multi-strand is preferably three strands.

[0076] The stretchable shielded wire prepared in this embodiment is a three-strand wire. Each formed flexible conductive layer is wrapped with a flexible inner insulating layer on the outside. The three flexible conductive layers wrapped with a flexible inner insulating layer on the outside are sequentially wrapped with a flexible shielding layer and a flexible outer insulating layer. The structure is shown in Figure 3 , the diameter of the conductive layer is 5 mm, the thickness of the inner insulating layer is 0.4 mm, the thickness of the shielding layer is 0.3 mm, the thickness of the outer insulating layer is 3.5 mm, the shielding effectiveness of the wire is 75 db, it can be stretched by 230% along the wire length direction, the resistance per unit length of the wire is 0.65 Ω / m, when the stretching rate of the wire is 80% of the elongation at break, the resistance per unit length of the wire is 0.72 Ω / m, and the shielding effectiveness of the wire is 62 db.

[0077] In Example 3, a flexible and stretchable shielded wire was prepared by a die forming method.

[0078] The method is the same as that of Example 1, except that the formula of the conductive layer is different. The conductive layer formula in Example 3 is 15 wt% silver nanowires and 85 wt% hydroxypropyl methylcellulose.

[0079] The structure of the flexible and stretchable shielded wire prepared by the method of Example 3 can be referred to Figure 2 , the diameter of the conductive layer of the flexible and stretchable shielded wire prepared in this embodiment is 5 mm, the thickness of the inner insulating layer is 0.4 mm, the thickness of the shielding layer is 0.3 mm, the thickness of the outer insulating layer is 3.5 mm, the shielding effectiveness of the wire is 69 db, it can be stretched by 236% along the wire length direction, the resistance per unit length of the wire is 1.5 Ω / m, when the stretching rate of the wire is 80% of the elongation at break, the resistance per unit length of the wire is 16.8 Ω / m, and the shielding effectiveness of the wire is 57 db.

[0080] Example 4 A flexible and stretchable shielded wire was prepared by a die forming method.

[0081] The method was the same as that of Example 1, except that the conductive layer and the shielding layer had different formulations. The formulation of the conductive layer was 10 wt% gallium-aluminum alloy, 20 wt% gold nanowires, and 70 wt% waterborne polyurethane; the formulation of the shielding layer was 1 wt% aluminum titanium carbide, 15 wt% silver nanoparticles, and 84 wt% waterborne acrylic resin.

[0082] The structure of the flexible and stretchable shielded wire prepared by the method of Example 4 can be referred to Figure 2 , the flexible and stretchable shielded wire prepared in this example had a conductive layer diameter of 5 mm, an inner insulating layer thickness of 0.4 mm, a shielding layer thickness of 0.3 mm, an outer insulating layer thickness of 3.5 mm, a wire shielding effectiveness of 67 db, a stretchability of 235% along the wire length direction, a wire unit length resistance of 0.59 Ω / m, a wire unit length resistance of 0.71 Ω / m when the wire stretch rate was 80% of the elongation at break, and a wire shielding effectiveness of 54 db.

[0083] Example 5 A flexible and stretchable shielded wire was prepared by a die forming method.

[0084] The method was the same as that of Example 1, except that the conductive layer and the shielding layer had different formulations. The formulation of the conductive layer was 2 wt% gallium-tin-indium alloy, 30 wt% graphene, and 68 wt% waterborne polyacrylic acid resin; the formulation of the shielding layer was 20 wt% graphene, 6 wt% silver nanowires, and 74 wt% waterborne polyurethane.

[0085] The structure of the flexible and stretchable shielded wire prepared by the method of Example 5 can be referred to Figure 2 , the flexible and stretchable shielded wire prepared in this example had a conductive layer diameter of 5 mm, an inner insulating layer thickness of 0.4 mm, a shielding layer thickness of 0.3 mm, an outer insulating layer thickness of 3.5 mm, a wire shielding effectiveness of 80 db, a stretchability of 210% along the wire length direction, a wire unit length resistance of 0.57 Ω / m, a wire unit length resistance of 0.75 Ω / m when the wire stretch rate was 80% of the elongation at break, and a wire shielding effectiveness of 67 db.

[0086] Example 6 A flexible and stretchable shielded wire was prepared by combining coaxial printing and die forming.

[0087] Preparation of the conductive layer: According to the formula of 6 wt% gallium-tin-indium alloy, 30 wt% copper nanowires, 59 wt% hydroxyl-terminated PDMS (i.e., hydroxyl-terminated polydimethylsiloxane), and 5 wt% boric acid, weigh each material. After mixing evenly by mechanical stirring, gradually heat to 165 °C. After maintaining for 1.5 hours, the cross-linking agent solid powder boric acid reacts with the hydroxyl-terminated PDMS to form borate bonds. The system is in the form of a transparent colloid. Cool down to room temperature and load it into a syringe for standby;

[0088] Preparation of the inner insulating layer: According to the formula of 95 wt% hydroxyl-modified polyurethane and 5 wt% phenylboric acid, weigh each material. After mixing evenly by mechanical stirring, gradually heat to 160 °C. After maintaining for 2 hours, the cross-linking agent solid powder phenylboric acid reacts with the hydroxyl-modified polyurethane to form borate bonds. The system is in the form of a transparent colloid. Cool down to room temperature and load it into a syringe for standby;

[0089] Preparation of the shielding layer: Prepare according to the formula of 3 wt% carbon nanotubes, 9 wt% nickel nanoparticles, and 89 wt% aqueous polyacrylic resin. Add water with a weight 10 times that of the aqueous polyacrylic resin. Weigh each material and mix evenly by mechanical stirring for standby;

[0090] Preparation of the outer insulating layer: The outer insulating layer is polydimethylsiloxane, and the added solvent is N,N-dimethyl. The amount of the solvent added is 1 time the weight of the polydimethylsiloxane. Weigh each material and mix evenly by mechanical stirring for standby.

[0091] As Figure 4 and Figure 5 shown, load the conductive layer and the inner insulating layer materials into the printing syringes 1 and 2 respectively. Specifically, the printing syringes 1 and 2 are respectively connected in one-to-one correspondence with the dispensing systems of the inner layer and the outer layer of the nozzle. Regulate the printing parameters and perform coaxial printing. Preferably, the printing speed is 20 mm / s, the printing air pressure of the conductive layer is 25 psi, and the printing air pressure of the inner insulating layer is 50 psi. Finally, a flexible conductive layer coated with a flexible inner insulating layer on the outside is obtained, where the diameter of the conductive layer is 3 mm and the thickness of the inner insulating layer is 0.5 mm.

[0092] In this embodiment, Figure 1The shown mold, the first mold and the second mold are used to prepare a flexible shielding layer and a flexible outer insulating layer in sequence, wherein the radius of the cylindrical cavity of the second mold is larger than that of the first mold. A flexible conductive layer with multiple strands formed and covered with a flexible inner insulating layer on the outside is placed at the central position of the first mold, and the uniformly mixed shielding layer material is put into the first mold. After curing and forming by heating at 90 °C for 15 minutes, the first mold is removed, and a flexible conductive layer formed with a flexible inner insulating layer and a flexible shielding layer covered from the inside to the outside is obtained; the flexible conductive layer formed with a flexible inner insulating layer and a flexible shielding layer covered from the inside to the outside is placed at the central position of the second mold, and the uniformly mixed flexible outer insulating layer material is put into the second mold. After curing and forming by heating at 110 °C for 8 minutes, the second mold is removed, and a formed flexible stretchable shielding wire is obtained, wherein the flexible conductive layer of the flexible stretchable shielding wire is covered with a flexible inner insulating layer, a flexible shielding layer and a flexible outer insulating layer from the inside to the outside. In this embodiment, the multiple strands are preferably three strands.

[0093] The flexible stretchable shielding wire prepared in this embodiment is a three-strand wire. Each formed conductive layer is covered with an inner insulating layer on the outside, and the three conductive layers covered with an inner insulating layer on the outside are sequentially covered with a shielding layer and an outer insulating layer. Its structure is as Figure 3 shown. The diameter of the conductive layer is 3 mm, the thickness of the inner insulating layer is 0.5 mm, the thickness of the shielding layer is 0.4 mm, the thickness of the outer insulating layer is 3.5 mm, the shielding effectiveness of the wire is 62 db, it can be stretched by 250% along the length direction of the wire, the resistance per unit length of the wire is 0.53 Ω / m, when the stretching rate of the wire is 80% of the elongation at break, the resistance per unit length of the wire is 0.54 Ω / m, and the shielding effectiveness of the wire is 49 db.

[0094] Comparative Example 1

[0095] The method is the same as that of Example 1, the difference is that the formula of the shielding layer is different. The shielding layer formula of Comparative Example 1 does not contain carbon nanotubes, and its formula is 10 wt% nickel nanoparticles and 90 wt% waterborne acrylic resin.

[0096] The diameter of the conductive layer of the flexible stretchable shielding wire prepared in Comparative Example 1 is 5 mm, the thickness of the inner insulating layer is 0.4 mm, the thickness of the shielding layer is 0.3 mm, the thickness of the outer insulating layer is 3.5 mm, the shielding effectiveness of the wire is 43 db, it can be stretched by 230% along the length direction of the wire, the resistance per unit length of the wire is 0.7 Ω / m, when the stretching rate of the wire is 80% of the elongation at break, the resistance per unit length of the wire is 0.81 Ω / m, and the shielding effectiveness of the wire is 23 db.

[0097] In the present invention, terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0098] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A flexible and stretchable shielding wire, characterized in that, it sequentially includes a flexible conductive layer, a flexible inner insulating layer, a flexible shielding layer and a flexible outer insulating layer from inside to outside, and the flexible shielding layer includes: 1 - 20% of a first conductive component; 6 - 15% of a second conductive component; and 65 - 93% of a resin; by mass percentage; wherein, the first conductive component includes at least one of graphene, carbon nanotubes or aluminum titanium carbide; the second conductive component includes at least one of silver nanowires, silver nanoparticles, nickel nanoparticles, copper nanowires, copper nanoparticles, gold nanowires or gold nanoparticles. The first conductive component improves the conductive connection between the second conductive components and increases the conductive path; the resin includes at least one of cellulose derivatives, waterborne polyurethane or waterborne polyacrylate resin; the flexible conductive layer includes 0 - 10% of liquid metal, 8 - 30% of nano conductive material and 60 - 92% of resin by mass percentage.

2. The flexible and stretchable shielding wire according to claim 1, characterized in that, the liquid metal includes at least one of gallium indium alloy, gallium tin indium alloy, gallium aluminum alloy or gallium bismuth alloy, and the content is 2 - 10%; and / or, the nano conductive material includes at least one of silver nanowires, silver nanoparticles, copper nanowires, copper nanoparticles, gold nanowires, gold nanoparticles, carbon nanotubes or graphene; and / or, the resin includes at least one of cellulose derivatives, waterborne polyurethane or waterborne polyacrylate resin.

3. The flexible and stretchable shielding wire according to claim 2, characterized in that, the cellulose derivative is hydroxypropyl methyl cellulose, hydroxyethyl cellulose or carboxymethyl cellulose.

4. The flexible and stretchable shielding wire according to claim 1, characterized in that, the flexible inner insulating layer or outer insulating layer includes at least one of thermoplastic polyurethane, polydimethylsiloxane, acrylic resin or epoxy resin.

5. A preparation method of the flexible and stretchable shielding wire according to any one of claims 1 - 4, characterized in that, it includes the following steps: a. Put the flexible conductive layer material into a first mold, heat and cure it into a shape, and then remove the first mold to obtain a formed flexible conductive layer; b. Put the formed flexible conductive layer obtained in step a into the central position of a second mold, put the flexible inner insulating layer material into the second mold, heat and cure it into a shape, and then remove the second mold to obtain a flexible conductive layer with a formed flexible inner insulating layer coated on the outside; c. Put the formed flexible conductive layer with a formed flexible inner insulating layer coated on the outside obtained in step b into the central position of a third mold, put the flexible shielding layer material into the third mold, heat and cure it into a shape, and then remove the third mold to obtain a formed flexible conductive layer sequentially coated with a flexible inner insulating layer and a flexible shielding layer from inside to outside; d. Place the formed flexible conductive layer coated with a flexible inner insulating layer and a flexible shielding layer from the inside to the outside obtained in step c at the center position of the fourth mold. Place the flexible outer insulating layer material into the fourth mold. After heating and curing to form, remove the fourth mold to obtain a formed flexible stretchable shielded wire.

6. The method for preparing a flexible stretchable shielded wire according to claim 5, wherein, in step a, b, c or d, the curing and forming temperature is 60 - 120 °C, and the curing time is 10 - 90 minutes.

7. A method for preparing a flexible stretchable shielded wire, wherein, the flexible stretchable shielded wire sequentially includes a flexible conductive layer, a flexible inner insulating layer, a flexible shielding layer, and a flexible outer insulating layer from the inside to the outside. The flexible shielding layer includes: 1 - 20% of a first conductive component, 6 - 15% of a second conductive component, and 65 - 93% of a resin, by mass percentage. Among them, the first conductive component includes at least one of graphene, carbon nanotubes, or aluminum titanium carbide; the second conductive component includes at least one of silver nanowires, silver nanoparticles, nickel nanoparticles, copper nanowires, copper nanoparticles, gold nanowires, or gold nanoparticles. The first conductive component improves the conductive lap between the second conductive components and increases the conductive path; the resin includes at least one of cellulose derivatives, waterborne polyurethane, or waterborne polyacrylic resin; The method for preparing the flexible stretchable shielded wire includes the following steps: a. Take the materials of the flexible conductive layer, flexible inner insulating layer, flexible shielding layer, and flexible outer insulating layer in the designed proportions. The flexible conductive layer includes 0 - 20% of liquid metal, 10 - 40% of nano conductive material, 30 - 87% of resin, and 3 - 10% of crosslinking agent; the flexible inner insulating layer includes 90 - 97% of resin and 3 - 10% of crosslinking agent, by mass percentage. Among them, the liquid metal includes at least one of gallium indium alloy, gallium tin indium alloy, gallium aluminum alloy, or gallium bismuth alloy; the nano conductive material includes at least one of silver nanowires, silver nanoparticles, copper nanowires, copper nanoparticles, gold nanowires, gold nanoparticles, carbon nanotubes, or graphene; the resin includes at least one of hydroxyl - terminated polydimethylsiloxane, hydroxyl - modified polyurethane, or natural rubber; the crosslinking agent includes at least one of boric acid or phenylboric acid; the flexible outer insulating layer includes at least one of thermoplastic polyurethane, polydimethylsiloxane, acrylic resin, or epoxy resin; b. Load the materials of the flexible conductive layer and the flexible inner insulating layer described in step a into syringes respectively, and perform coaxial printing to obtain a formed flexible conductive layer coated with a flexible inner insulating layer on the outside; c. Place the formed flexible conductive layer coated with a flexible inner insulating layer on the outside obtained in step b at the center position of the first mold. Place the flexible shielding layer into the first mold. After heating and curing to form, remove the first mold to obtain a formed flexible conductive layer coated with a flexible inner insulating layer and a flexible shielding layer from the inside to the outside; d. Place the formed flexible conductive layer coated with a flexible inner insulating layer and a flexible shielding layer from the inside out obtained in step c at the central position of the second mold. Place the flexible outer insulating layer into the second mold. After heating and curing to form, remove the second mold to obtain a formed flexible stretchable shielded wire.

8. The method for preparing a flexible stretchable shielded wire according to claim 7, wherein, in step b, the flexible conductive layer and the flexible inner insulating layer material described in step a are respectively heated to 160 - 190 °C, held for 1 - 3 hours, then cooled to room temperature, and respectively loaded into syringes for coaxial printing. The printing speed is 0.5 - 100 mm / s, and the printing air pressure is 5 - 90 psi; and / or, in step c or d, the curing temperature is 60 - 120 °C, and the curing time is 10 - 90 minutes.

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