Flexible stretchable conductive shielding materials and methods of making the same

Abstract

The application discloses a kind of flexible stretchable conductive shielding materials and preparation method thereof, the conductive shielding material includes stretchable conductive shielding layer, the preparation raw material of the stretchable conductive shielding layer includes by weight parts: elastic material 100 parts;First conductive material 200-300 parts;First solvent 100-400 parts;Auxiliary agent 0.1-5 parts;Wherein, the conductive material includes conductive particle and conductive fiber, and the conductive fiber is 5-50 parts.The flexible stretchable conductive shielding material provided by the application includes the stretchable conductive shielding layer in middle layer and the conductive adhesive layer or insulating protective layer located in the upper and lower stretchable conductive shielding layer, and the conductive adhesive layer or insulating protective layer can facilitate product bonding or provide insulation protection;The conductive shielding material of the application has strong tensile property and conductive shielding performance, and the product process is simple, and can realize roll-to-roll mass production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of conductive shielding materials, in particular to a flexible stretchable conductive shielding material and a preparation method thereof. BACKGROUND

[0002] With the continuous development of electronic technology, more and more electronic devices, especially wearable devices, have higher requirements for the miniaturization and flexibility of devices. In the existing technology, the mainstream flexible conductive materials mainly have three directions: 1. The combination of conductive materials and high polymer materials, that is, the combination of conductive materials and flexible high polymer materials through coating, electroplating, doping and other processes to become flexible conductive materials, but the doping of the material is too high, and the process and mass production are difficult, and the resistance of the material rises quickly after stretching to a certain extent, and because the material has no adhesion, the contact resistance is unstable when bonding with other materials, affecting the conductivity and shielding effect. 2. Liquid metal material, mainly gallium-based liquid metal and zirconium-based liquid metal, but the initial state of the liquid metal material has poor conductivity and high surface free energy, which is difficult to adhere, and the liquid metal has a large flowability, which has a risk of leakage during stretching. 3. Conductive polymer material, such as polypyrrole, polythiophene or polyaniline, but the intrinsic conductivity of the conductive polymer material is currently relatively poor and cannot meet the application requirements. 4. The method of pre-stretching the material to form wrinkles or curls to form the stretching performance of the material, but the performance process is relatively complex and the mass production is insufficient. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a flexible stretchable conductive shielding material and a preparation method thereof in view of the deficiencies in the prior art.

[0004] To solve the above technical problems, the technical solution adopted by the present application is: a flexible stretchable conductive shielding material, including a stretchable conductive shielding layer, the preparation raw material of the stretchable conductive shielding layer includes, by weight:

[0005]

[0006]

[0007] Among them, the conductive material includes conductive particles and conductive fibers, and the conductive fibers are 5-50 parts.

[0008] Preferably, the elastic material is a thermosetting or thermoplastic elastomer;

[0009] The material of the first conductive material is one or more of gold, silver, copper, silver-copper composite material, nickel, graphene and carbon nanotube;

[0010] The conductive particle has a particle size of 0.1-50 μm, and the conductive fiber material has a length of 10-50 μm and a diameter of 1-100 nm.

[0011] Preferably, the first solvent is at least one of butanone, dimethylformamide, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, diethylene glycol butyl ether acetate, diethylene glycol butyl ether, dimethylbenzene or isophorone.

[0012] The auxiliary agent is one or more of dispersants, coupling agents, surfactants, anti-aging agents, anti-hydrolysis agents and defoaming agents.

[0013] Preferably, the flexible stretchable conductive shielding material further comprises a conductive adhesive layer, and the preparation raw materials of the conductive adhesive layer comprise, by weight:

[0014]

[0015] Preferably, the thermoplastic or thermosetting resin is one or more of acrylic resin, terpene phenol tackifying resin, epoxy resin, polyurethane resin, phenolic resin, polyester resin, polyamide resin, polyolefin resin, EVA resin and SBS resin.

[0016] Preferably, the second conductive material is one or more of gold powder, silver powder, copper powder, silver-copper powder, nickel powder, graphene and carbon nanotube.

[0017] The second conductive material is a particulate material having a particle size of 20-50 μm.

[0018] Preferably, the flexible stretchable conductive shielding material further comprises an insulating protective layer, and the preparation raw materials of the insulating protective layer comprise, by weight:

[0019]

[0020]

[0021] Preferably, the thermosetting or thermoplastic elastomer is one or more of nitrile rubber, silicone rubber, polyurethane elastomer and polyolefin elastomer.

[0022] The third solvent is a mixture of dimethylformamide, dimethylbenzene and butanone.

[0023] The second auxiliary agent is one or more of dispersants, coupling agents, surfactants, anti-aging agents, anti-hydrolysis agents and defoaming agents.

[0024] Preferably, the flexible stretchable conductive shielding material further comprises a protective layer arranged outside the conductive adhesive layer or the insulating protective layer, and the flexible stretchable conductive shielding material comprises two different structures:

[0025] Flexible stretchable conductive shielding material a: the stretchable conductive shielding layer is provided with the conductive adhesive layer on both sides, and the outer layer of the conductive adhesive layer is provided with a protective layer;

[0026] Flexible stretchable conductive shielding material b: the stretchable conductive shielding layer is provided with the conductive adhesive layer on one side and the insulating protective layer on the other side, and the outer layer of the conductive adhesive layer and the insulating protective layer is provided with a protective layer.

[0027] The application also provides a preparation method of the flexible stretchable conductive shielding material, comprising the following steps:

[0028] S1, preparing stretchable conductive shielding layer glue: uniformly mixing 100 parts of elastic material, 200-300 parts of first conductive material, 100-400 parts of first solvent and 0.1-5 parts of auxiliary agent by weight to obtain the stretchable conductive shielding layer glue;

[0029] S2, preparing conductive adhesive layer glue: uniformly mixing 130 parts of thermoplastic or thermosetting resin and 40-160 parts of second solvent by weight, then adding 5-20 parts of second conductive material, stirring, and then adding MDI curing agent and stirring uniformly to obtain the conductive adhesive layer glue;

[0030] S3, preparing insulating protective layer glue: dissolving 100 parts of thermosetting or thermoplastic elastomer in 100-400 parts of third solvent, then adding 1.5-6 parts of color paste and stirring, and then adding 0.5-2 parts of second auxiliary agent and stirring uniformly to obtain the insulating protective layer glue;

[0031] S4, uniformly coating the stretchable conductive shielding layer glue on the release film, forming the stretchable conductive shielding layer on the release film after drying, obtaining intermediate product 1; uniformly coating the conductive adhesive layer glue on the protective layer, forming the conductive adhesive layer on the protective layer after drying, obtaining intermediate product 2; and uniformly coating the insulating protective layer glue on the protective layer, forming the insulating protective layer on the protective layer after drying, obtaining intermediate product 3;

[0032] S5, tearing off the release film of the intermediate product 1, and then adhering to prepare two kinds of flexible stretchable conductive shielding materials with different structures by the following method:

[0033] (1) adhering the stretchable conductive shielding layer on both sides to one conductive adhesive layer of the intermediate product 2 to obtain the flexible stretchable conductive shielding material a;

[0034] (2), the first face of the stretchable conductive shielding layer is attached to the conductive adhesive layer of an intermediate product 2, and the second face of the stretchable conductive shielding layer is attached to the insulating protective layer of an intermediate product 3, to obtain a flexible stretchable conductive shielding material b.

[0035] The present application has the following advantages:

[0036] The present application provides a flexible stretchable conductive shielding material and a preparation method thereof. The conductive shielding material comprises a stretchable conductive shielding layer in a middle layer and conductive adhesive layers or insulating protective layers above and below the stretchable conductive shielding layer. The conductive adhesive layers or insulating protective layers can facilitate product bonding or provide insulation protection. The conductive shielding material of the present application has strong stretchability and conductive shielding performance, and the product process is simple, and mass production can be realized by roll-to-roll connection. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 Fig. 1 is a structural schematic diagram of a flexible stretchable conductive shielding material of the present application;

[0038] Figure 2 Fig. 2 is a structural schematic diagram of another flexible stretchable conductive shielding material of the present application;

[0039] Figure 3 Fig. 3 is a schematic diagram of an initial shielding effectiveness test in the present application;

[0040] Figure 4 Fig. 4 is a schematic diagram of a stretch shielding effectiveness test in the present application;

[0041] Figure 5 Fig. 5 is a schematic diagram of a lap joint resistance test in the present application;

[0042] Figure 6 Fig. 6 is a change trend graph of the back resistance of the flexible stretchable conductive shielding material of Examples 1 to 5 of the present application after stretching;

[0043] Figure 7 Fig. 7 is a change trend graph of the back resistance of the flexible stretchable conductive shielding material of Comparative Examples 1 to 5 of the present application after stretching.

[0044] Explanation of reference signs:

[0045] 1 - stretchable conductive shielding layer; 2 - conductive adhesive layer; 3 - insulating protective layer; 4 - protective layer. DETAILED DESCRIPTION

[0046] The present application will be further described in detail below with reference to the examples, so that those skilled in the art can implement the present application according to the description.

[0047] It should be understood that the terms such as "have", "contain" and "include" used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0048] The test methods used in the following examples are conventional methods unless otherwise specified. The materials and reagents used in the following examples are commercially available unless otherwise specified. The specific conditions not specified in the following examples are carried out under conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, but are conventional products that can be purchased on the market.

[0049] The present application provides a flexible stretchable conductive shielding material, including a stretchable conductive shielding layer, the preparation raw materials of the stretchable conductive shielding layer, including by weight:

[0050]

[0051] In a preferred embodiment, the first conductive material uses a composite of flaky conductive particles and conductive fibers, wherein the conductive fibers are 5-50 parts. The conductive particles provide good conductivity on the one hand, and the flaky conductive particles have higher surface area to provide better shielding effect, and the relative slip between the flaky particles improves the flexibility and stretchability of the material when stretched. The conductive fiber material can play a role in connecting the conductive particles when stretched, reducing the rate of resistance rise. In a further preferred embodiment, the material of the first conductive material is one or more of gold, silver, copper, silver-copper composite material, nickel, graphene, carbon nanotube; the particle size of the conductive particles is 0.1-50μm, and the length of the conductive fiber material is 10-50μm and the diameter is 1-100nm.

[0052] The overall conductivity and shielding performance are too poor if the amount of the first conductive material is too small, and the flexibility and stretchability are too poor if the amount is too large, so the preferred amount is 200-300 parts. The resistance rises too fast after stretching if the amount of conductive fibers is too small, and the overall dispersibility and shielding performance are affected if the amount is too large, so the preferred amount is 5-50 parts.

[0053] In a preferred embodiment, the elastic material is a thermosetting or thermoplastic elastomer; in combination with the application and the demand for elasticity, it is further preferred that the elastic material is a thermoplastic polyurethane elastomer.

[0054] In a preferred embodiment, the first solvent is at least one of butanone, dimethylformamide, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, diethylene glycol butyl ether acetate, diethylene glycol butyl ether, dimethylbenzene or isophorone.

[0055] In a preferred embodiment, the auxiliary agent is one or more of a dispersant, a coupling agent, a surfactant, an antioxidant, an anti-hydrolysis agent, and a defoaming agent.

[0056] In a preferred embodiment, the flexible stretchable conductive shielding material further comprises a conductive adhesive layer, the raw materials for preparing the conductive adhesive layer comprise, by weight fraction:

[0057]

[0058] In a preferred embodiment, the thermoplastic or thermosetting resin is one or more of acrylic resin, terpene phenolic tackifying resin, epoxy resin, polyurethane resin, phenolic resin, polyester resin, polyamide resin, polyolefin resin, EVA resin, SBS resin. In a more preferred embodiment, the thermoplastic or thermosetting resin comprises 100 parts by weight of acrylic resin and 30 parts by weight of terpene phenolic tackifying resin.

[0059] In a preferred embodiment, the conductive adhesive layer has a thickness of 20-50 μm.

[0060] In a preferred embodiment, the second conductive material is one or more of gold powder, silver powder, copper powder, silver copper powder, nickel powder, graphene, carbon nanotube. In a more preferred embodiment, the second conductive material is a particulate material with a particle size of 20-50 μm.

[0061] In a preferred embodiment, the flexible stretchable conductive shielding material further comprises an insulating protective layer, the raw materials for preparing the insulating protective layer comprise, by weight fraction:

[0062]

[0063] In a preferred embodiment, the thermosetting or thermoplastic elastomer is one or more of nitrile rubber, silicone rubber, polyurethane elastomer, polyolefin elastomer.

[0064] In a preferred embodiment, the third solvent is a mixture of dimethylformamide, dimethylbenzene, butanone.

[0065] In a preferred embodiment, the second auxiliary agent is one or more of dispersant, coupling agent, surfactant, antioxidant, anti-hydrolysis agent, defoaming agent.

[0066] In a preferred embodiment, in order to facilitate identification and appearance uniformity, the raw materials for preparing the insulating protective layer further add color paste. The color paste is black, red, yellow, blue, white, green, etc. The preferred color paste is black paste.

[0067] In a preferred embodiment, the thickness of the insulating shielding layer is 5-20 μm.

[0068] In a preferred embodiment, the flexible stretchable conductive shielding material further comprises a protective layer arranged outside the conductive adhesive layer or the insulating protective layer, and the flexible stretchable conductive shielding material comprises two different structures as follows:

[0069] The flexible stretchable conductive shielding material a: the two sides of the stretchable conductive shielding layer 1 are provided with the conductive adhesive layer 2, and the outer layer of the conductive adhesive layer 2 is provided with the protective layer 4, as shown in Figure 1 ;

[0070] The flexible stretchable conductive shielding material b: one side of the stretchable conductive shielding layer 1 is provided with the conductive adhesive layer 2, and the other side is provided with the insulating protective layer 3, and the outer layer of the conductive adhesive layer 2 and the insulating protective layer 3 is provided with the protective layer 4, as shown in Figure 2 .

[0071] The application further provides a preparation method of the flexible stretchable conductive shielding material as above, comprising the following steps:

[0072] S1, preparing stretchable conductive shielding layer glue: uniformly mixing 100 parts of elastic material, 200-300 parts of first conductive material, 100-400 parts of first solvent and 0.1-5 parts of auxiliary agent by weight to obtain the stretchable conductive shielding layer glue;

[0073] S2, preparing conductive adhesive layer glue: uniformly mixing 130 parts of thermoplastic or thermosetting resin and 40-160 parts of second solvent by weight, then adding 5-20 parts of second conductive material, stirring, and then adding MDI curing agent and stirring uniformly to obtain the conductive adhesive layer glue;

[0074] S3, preparing insulating protective layer glue: dissolving 100 parts of thermosetting or thermoplastic elastomer in 100-400 parts of third solvent, then adding 1.5-6 parts of color paste and stirring, and then adding 0.5-2 parts of second auxiliary agent and stirring uniformly to obtain the insulating protective layer glue;

[0075] S4, uniformly coating the stretchable conductive shielding layer glue on the release film, and forming the stretchable conductive shielding layer on the release film after drying to obtain intermediate product 1; uniformly coating the conductive adhesive layer glue on the protective layer, and forming the conductive adhesive layer on the protective layer after drying to obtain intermediate product 2; uniformly coating the insulating protective layer glue on the protective layer, and forming the insulating protective layer on the protective layer after drying to obtain intermediate product 3;

[0076] S5, tearing off the release film of the intermediate product 1, and then preparing two different structures of the flexible stretchable conductive shielding material by the following method:

[0077] (1) The two sides of the stretchable conductive shielding layer are respectively combined with the conductive adhesive layer of one intermediate product 2 to obtain the flexible stretchable conductive shielding material a;

[0078] (2), the first side of the stretchable conductive shielding layer is attached to the conductive adhesive layer of an intermediate product 2, and the second side of the stretchable conductive shielding layer is attached to the insulating protective layer of an intermediate product 3, to obtain a flexible stretchable conductive shielding material b.

[0079] The protective layer is a release film or release paper or the like, and has a thickness of 23-100 μm.

[0080] The above is the general idea of the present application, and the following provides detailed examples and comparative examples based thereon to further illustrate the present application.

[0081] Example 1

[0082] A flexible stretchable conductive shielding material, the preparation method thereof comprising the following steps:

[0083] S1, preparing a stretchable conductive shielding layer glue:

[0084] The TPU resin 100 parts are dissolved in 80 parts of dimethylformamide, 80 parts of dimethylbenzene, and 40 parts of butanone at 40°C, and then 240 parts of flaky silver powder and 20 parts of nanosilver fiber are added, and the obtained mixture is dispersed at a high speed of 2000 RPM for 20 min; then 1 part of an antioxidant, 1 part of a defoaming agent, and 0.5 parts of an anti-hydrolysis agent are added, and the mixture is slowly stirred and dispersed at 300 RPM for 30 min, and then vacuum degassing is performed at -0.95 MPa for 20 min, to obtain the stretchable conductive shielding layer glue.

[0085] The average particle size of the silver powder is 10 μm, the thickness is 0.5 μm, the length of the nanosilver fiber is 15 μm, and the diameter is 20-30 nm.

[0086] S2, preparing a conductive adhesive layer glue:

[0087] The pressure-sensitive acrylic resin 100 parts, the terpene phenol tackifying resin 30 parts, and the particulate conductive silver powder 10 parts are dissolved in 80 parts of ethyl acetate, mixed uniformly, and then the particulate conductive silver powder 10 parts is added, and the mixture is stirred at 1000 RPM for 30 min, and then the MDI curing agent 1.2 parts is added, and the mixture is stirred at 500 RPM for 20 min, to obtain the conductive adhesive layer glue.

[0088] S3, preparing an insulating protective layer glue:

[0089] The TPU resin 100 parts by weight, using 80 parts of dimethylformamide, 80 parts of dimethylbenzene, 40 parts of butanone at 40°C was dissolved, 3 parts of milled carbon black paste was added, the obtained mixture was dispersed at high speed at 2000 RPM for 20 min, then 0.5 parts of antioxidant and 0.5 parts of anti-hydrolysis agent were added, stirred at 300 RPM for 20 min, vacuum degassing at -0.95 MPa for 20 min, to prepare the insulating protective layer glue. Among them, the carbon black paste has a carbon black particle size of 50 nm.

[0090] S4, preparation of intermediate products:

[0091] The stretchable conductive shielding layer glue was coated on the release film using SLOTDIE coating method, with a coating thickness of 30 μm, and was baked (70°C*5min+120°C*5min) to dry, then a stretchable conductive shielding layer was formed on the release film after drying, to prepare intermediate product 1.

[0092] The conductive adhesive layer glue was uniformly coated on the protective layer using a doctor blade coating method, and a conductive adhesive layer was formed on the protective layer after drying, to obtain intermediate product 2, with a conductive adhesive layer thickness of 20 μm.

[0093] The insulating protective layer glue was uniformly coated on the protective layer using SLOTDIE, and an insulating protective layer was formed on the protective layer after drying, to obtain intermediate product 3; the insulating protective layer has a thickness of 10 μm.

[0094] S5, the release film of intermediate product 1 was torn off, then the first surface of the stretchable conductive shielding layer was attached to a conductive adhesive layer of intermediate product 2, and the second surface of the stretchable conductive shielding layer was attached to an insulating protective layer of intermediate product 3, to obtain a flexible stretchable conductive shielding material.

[0095] Among them, the protective layer is a release film, with a thickness of 50 μm.

[0096] Example Two

[0097] The difference between this example and Example 1 is only in the stretchable conductive shielding layer glue formula in step S1, and only the differences are listed below:

[0098] In this example, S1, the preparation of stretchable conductive shielding layer glue is as follows:

[0099] The TPU resin 100 parts by weight is dissolved at 40°C using 80 parts of dimethylformamide, 80 parts of xylene, and 40 parts of butanone, and then 5 parts of carbon nanotube fiber and 0.5 parts of hyperdispersant (Solsperse 36600 of Lubrizol) are added and ultrasonically dispersed for 20 min, and then 255 parts of flaky silver powder are added, and the obtained mixed liquid is high-speed sheared and dispersed at 2000 RPM for 20 min; then 1 part of antioxidant, 1 part of defoaming agent, and 0.5 parts of anti-hydrolysis agent are added, and slowly stirred and dispersed at 300 RPM for 30 min, and vacuum degassed at -0.95 MPa for 20 min to prepare the stretchable conductive shielding layer glue.

[0100] Example Three

[0101] The difference between this example and Example 1 is only the formula of the stretchable conductive shielding layer glue in step S1, and only the difference is shown as follows:

[0102] In this example, S1, preparation of the stretchable conductive shielding layer glue, is specifically:

[0103] The TPU resin 100 parts by weight is dissolved at 40°C using 80 parts of dimethylformamide, 80 parts of xylene, and 40 parts of butanone, and then 5 parts of carbon nanotube fiber and 0.5 parts of hyperdispersant (Solsperse 36600 of Lubrizol) are added and ultrasonically dispersed for 20 min, and then 255 parts of flaky silver powder are added, and the obtained mixed liquid is high-speed sheared and dispersed at 2000 RPM for 20 min; then 1 part of antioxidant, 1 part of defoaming agent, and 0.5 parts of anti-hydrolysis agent are added, and slowly stirred and dispersed at 300 RPM for 30 min, and vacuum degassed at -0.95 MPa for 20 min to prepare the stretchable conductive shielding layer glue.

[0104] Example Four

[0105] The difference between this example and Example 1 is only the formula of the stretchable conductive shielding layer glue in step S1, and only the difference is shown as follows:

[0106] In this example, S1, preparation of the stretchable conductive shielding layer glue, is specifically:

[0107] The TPU resin 100 parts by weight is dissolved at 40°C using 80 parts of dimethylformamide, 80 parts of xylene, and 40 parts of butanone, and then 5 parts of carbon nanotube fiber and 0.5 parts of hyperdispersant (Solsperse 36600 of Lubrizol) are added and ultrasonically dispersed for 20 min, and then 255 parts of flaky silver powder are added, and the obtained mixed liquid is high-speed sheared and dispersed at 2000 RPM for 20 min; then 1 part of antioxidant, 1 part of defoaming agent, and 0.5 parts of anti-hydrolysis agent are added, and slowly stirred and dispersed at 300 RPM for 30 min, and vacuum degassed at -0.95 MPa for 20 min to prepare the stretchable conductive shielding layer glue.

[0108] Example Five

[0109] The difference between this example and Example 1 is only the stretchable conductive shielding layer glue formula in step S1, and only the difference is listed as follows:

[0110] In this example, S1, the preparation of the stretchable conductive shielding layer glue is specifically as follows:

[0111] The TPU resin 100 parts are dissolved in 80 parts of dimethylformamide, 80 parts of dimethylbenzene, and 40 parts of butanone at 40°C, 200 parts of flaky silver powder and 20 parts of nanometer silver fiber are then added, and the obtained mixed liquid is dispersed at a high speed of 2000 RPM for 20 min; 1 part of an antioxidant, 1 part of a defoaming agent, and 0.5 parts of an anti-hydrolysis agent are then added, and the mixture is slowly stirred and dispersed at 300 RPM for 30 min, and vacuum degassing is performed at -0.95 MPa for 20 min to prepare the stretchable conductive shielding layer glue.

[0112] Comparative Example One

[0113] The difference between this example and Example 1 is only the stretchable conductive shielding layer glue formula in step S1, and only the difference is listed as follows:

[0114] In this example, S1, the preparation of the stretchable conductive shielding layer glue is specifically as follows:

[0115] The TPU resin 100 parts are dissolved in 80 parts of dimethylformamide, 80 parts of dimethylbenzene, and 40 parts of butanone at 40°C, 200 parts of flaky silver powder and 20 parts of nanometer silver fiber are then added, and the obtained mixed liquid is dispersed at a high speed of 2000 RPM for 20 min; 1 part of an antioxidant, 1 part of a defoaming agent, and 0.5 parts of an anti-hydrolysis agent are then added, and the mixture is slowly stirred and dispersed at 300 RPM for 30 min, and vacuum degassing is performed at -0.95 MPa for 20 min to prepare the stretchable conductive shielding layer glue.

[0116] Comparative Example Two

[0117] The difference between this example and Example 1 is only the stretchable conductive shielding layer glue formula in step S1, and only the difference is listed as follows:

[0118] In this example, S1, the preparation of the stretchable conductive shielding layer glue is specifically as follows:

[0119] The TPU resin 100 parts are dissolved in 80 parts of dimethylformamide, 80 parts of dimethylbenzene, and 40 parts of butanone at 40°C, 200 parts of flaky silver powder and 20 parts of nanometer silver fiber are then added, and the obtained mixed liquid is dispersed at a high speed of 2000 RPM for 20 min; 1 part of an antioxidant, 1 part of a defoaming agent, and 0.5 parts of an anti-hydrolysis agent are then added, and the mixture is slowly stirred and dispersed at 300 RPM for 30 min, and vacuum degassing is performed at -0.95 MPa for 20 min to prepare the stretchable conductive shielding layer glue.

[0120] Comparative Example Three

[0121] The difference between this example and Example 1 is only in the stretchable conductive shielding layer glue formula in step S1, and only the difference is listed as follows:

[0122] In this example, S1, the preparation of the stretchable conductive shielding layer glue is specifically:

[0123] The TPU resin 100 parts are dissolved in 80 parts of dimethylformamide, 80 parts of dimethylbenzene, and 40 parts of butanone at 40°C, and then 240 parts of dendritic silver powder and 20 parts of nanosilver fiber are added. The obtained mixed liquid is dispersed at a high speed of 2000 RPM for 20 min, 1 part of an antioxidant, 1 part of a defoaming agent, and 0.5 parts of an anti-hydrolysis agent are added, and the mixture is slowly stirred and dispersed at 300 RPM for 30 min, and then vacuum degassing is performed at -0.95 MPa for 20 min to prepare the stretchable conductive shielding layer glue.

[0124] Comparative Example Four

[0125] The difference between this example and Example 1 is only in the stretchable conductive shielding layer glue formula in step S1, and only the difference is listed as follows:

[0126] In this example, S1, the preparation of the stretchable conductive shielding layer glue is specifically:

[0127] The TPU resin 100 parts are dissolved in 80 parts of dimethylformamide, 80 parts of dimethylbenzene, and 40 parts of butanone at 40°C, and then 240 parts of dendritic silver powder and 20 parts of nanosilver fiber are added. The obtained mixed liquid is dispersed at a high speed of 2000 RPM for 20 min, 1 part of an antioxidant, 1 part of a defoaming agent, and 0.5 parts of an anti-hydrolysis agent are added, and the mixture is slowly stirred and dispersed at 300 RPM for 30 min, and then vacuum degassing is performed at -0.95 MPa for 20 min to prepare the stretchable conductive shielding layer glue.

[0128] Comparative Example Five

[0129] The difference between this example and Example 1 is only in the stretchable conductive shielding layer glue formula in step S1, and only the difference is listed as follows:

[0130] In this example, S1, the preparation of the stretchable conductive shielding layer glue is specifically:

[0131] The TPU resin 100 parts by weight is dissolved at 40℃ using 80 parts of dimethylformamide, 80 parts of dimethylbenzene, 40 parts of butanone, 257 parts of flaky silver powder and 3 parts of nanometer silver fiber are added, and the obtained mixture is dispersed at high speed under 2000 RPM for 20 min; 1 part of antioxidant, 1 part of defoaming agent and 0.5 part of anti-hydrolysis agent are added, and the mixture is dispersed under slow stirring at 300 RPM for 30 min, and vacuum degassing is performed under -0.95 MPa for 20 min to prepare the stretchable conductive shielding layer glue.

[0132] The flexible stretchable conductive shielding materials prepared in Examples 1 to 5 and Comparative Examples 1 to 5 are subjected to the following performance tests:

[0133] (1) The tensile strength and elongation at break are tested by using a universal tensile testing machine;

[0134] (2) The square resistance is tested by using a four-probe square resistance meter;

[0135] (3) Initial shielding effectiveness and tensile shielding effectiveness tests: the initial shielding effectiveness is the near-field shielding effectiveness measured by laying the material on the device (refer to Figure 3 ), and the tensile shielding effectiveness is the near-field shielding effectiveness measured by coating the device on the circuit board (refer to Figure 4 );

[0136] (4) The lap resistance is tested by using a milliohm meter, the test area is 4mm*4mm, the sample size is 4mm*20mm, and the specific test is shown in Figure 5 .

[0137] The test results are shown in Table 1 and Figure 6 , Figure 7 .

[0138] Table 1

[0139]

[0140] According to the test results, the powder addition amount of Comparative Example 1 is too small, the resistance and shielding effectiveness are poor, and the resistance increases rapidly after stretching. The powder addition amount of Comparative Example 2 is too high, and the overall tensile performance is too poor. Comparative Examples 3 and 4 use other morphology powders, the resistance is acceptable but the shielding effectiveness is slightly poor. The fibrous material in Comparative Example 5 is too small, and the resistance change rate is too high after stretching. The flexible stretchable conductive shielding material in the examples of the present application exhibits good conductivity, shielding and tensile performance.

[0141] While embodiments of the application have been disclosed in connection with the preferred embodiments of the application, as illustrated in the drawings and described above, those skilled in the art will readily appreciate that yet other modifications can be made to the application without departing from the concept and scope of the application as set forth in the claims and equivalents thereof.

Claims

1. A flexible, stretchable, electrically conductive shielding material, characterized in that, The flexible stretchable conductive shielding material comprises a stretchable conductive shielding layer, a conductive adhesive layer and an insulating protective layer. The stretchable conductive shielding layer is prepared from the following raw materials by weight: Elastic material 100 parts; First conductive material 200-300 parts; First solvent 100-400 parts; Auxiliary agent 0.1-5 parts; The first conductive material comprises flaky conductive particles and conductive fibers, and the conductive fibers are 5-50 parts; The conductive adhesive layer is prepared from the following raw materials by weight: Thermoplastic or thermosetting resin 130 parts; Second conductive material 5-20 parts; MDI curing agent 1.2-2.4 parts; Second solvent 40-160 parts; The insulating protective layer is prepared from the following raw materials by weight: Thermosetting or thermoplastic elastomer 100 parts; Third solvent 100-400 parts; Color paste 1.5-6 parts; Second auxiliary agent 0.5-2 parts; The flexible stretchable conductive shielding material further comprises a protective layer arranged on the outer layer of the conductive adhesive layer or the insulating protective layer, and the structure of the flexible stretchable conductive shielding material is as follows:

2. The flexible stretchable conductive shielding material of claim 1, wherein, One side of the stretchable conductive shielding layer is provided with the conductive adhesive layer, and the other side is provided with the insulating protective layer, and the outer layer of the conductive adhesive layer and the insulating protective layer is provided with a protective layer. The elastic material is a thermosetting or thermoplastic elastomer; The material of the first conductive material is one or more of gold, silver, copper, silver-copper composite material, nickel, graphene and carbon nanotube; 3. The flexible stretchable conductive shielding material of claim 2, wherein, The particle size of the flaky conductive particles is 0.1-50 μm, and the length of the conductive fiber material is 10-50 μm and the diameter is 1-100 nm. The first solvent is at least one of butanone, dimethylformamide, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, diethylene glycol butyl ether acetate, diethylene glycol butyl ether, dimethylbenzene or isophorone; 4. The flexible stretchable conductive shielding material of claim 1, wherein, The auxiliary agent is one or more of dispersing agent, coupling agent, surfactant, antioxidant, anti-hydrolysis agent and defoaming agent.

5. The flexible stretchable conductive shielding material of claim 4, wherein, The thermoplastic or thermosetting resin is one or more of acrylic resin, terpene phenolic tackifying resin, epoxy resin, polyurethane resin, phenolic resin, polyester resin, polyamide resin, polyolefin resin, EVA resin and SBS resin. The second conductive material is one or more of gold powder, silver powder, copper powder, silver-copper powder, nickel powder, graphene and carbon nanotube; 6. The flexible stretchable conductive shielding material of claim 1, wherein, The second conductive material is a particulate material with a particle size of 20-50 μm. The thermosetting or thermoplastic elastomer is one or more of nitrile rubber, silicone rubber, polyurethane elastomer and polyolefin elastomer; The third solvent is a mixture of dimethylformamide, dimethylbenzene and butanone; 7. A method of making the flexible stretchable conductive shielding material of claim 1, wherein, The second auxiliary agent is one or more of dispersing agent, coupling agent, surfactant, antioxidant, anti-hydrolysis agent and defoaming agent. The method comprises the following steps: S1, preparing stretchable conductive shielding layer glue: uniformly mixing 100 parts of elastic material, 200-300 parts of first conductive material, 100-400 parts of first solvent and 0.1-5 parts of auxiliary agent by weight to obtain stretchable conductive shielding layer glue; S2, preparing conductive adhesive layer glue: thermoplastic or thermosetting resin 130 parts by weight, second solvent 40-160 parts by weight are uniformly mixed, then the second conductive material 5-20 parts is added, stirring, then MDI curing agent is added, stirring, to obtain the conductive adhesive layer glue; S3, preparing insulation protective layer glue: thermosetting or thermoplastic elastomer 100 parts by weight is dissolved in 100-400 parts of third solvent, then color paste 1.5-6 parts is added, stirring, then second auxiliary agent 0.5-2 parts is added, stirring, to obtain the insulation protective layer glue; S4, the stretchable conductive shielding layer glue is uniformly coated on the release film, and the stretchable conductive shielding layer is formed on the release film after drying, to obtain intermediate product 1; the conductive adhesive layer glue is uniformly coated on the protective layer, and the conductive adhesive layer is formed on the protective layer after drying, to obtain intermediate product 2; the insulation protective layer glue is uniformly coated on the protective layer, and the insulation protective layer is formed on the protective layer after drying, to obtain intermediate product 3; S5, the release film of intermediate product 1 is torn off, and then the flexible stretchable conductive shielding material is prepared by the following method: the first surface of the stretchable conductive shielding layer is attached to the conductive adhesive layer of one intermediate product 2, and the second surface of the stretchable conductive shielding layer is attached to the insulation protective layer of one intermediate product 3, to obtain the flexible stretchable conductive shielding material.

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