Electromagnetic shielding adhesive tape based on composite electromagnetic nanoparticle layer and preparation method thereof
By introducing a FeNi metal layer and a composite magnetic nanoparticle layer into the electromagnetic shielding tape, the problem of poor shielding effect of existing electromagnetic shielding materials under low frequency and static magnetic field conditions is solved, realizing full-band electromagnetic shielding and lightweight design, which can be adapted to complex surface applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HANDAN COLLEGE
- Filing Date
- 2026-03-05
- Publication Date
- 2026-05-29
AI Technical Summary
Existing electromagnetic shielding materials are effective at shielding high-frequency electromagnetic waves, but their effectiveness is poor in low-frequency and static magnetic field environments. They are also heavy, easily corroded, and have poor flexibility, which limits their application in special occasions such as wearable devices and aerospace.
An electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer is used, including a protective layer, a FeNi metal layer, a composite electromagnetic nanoparticle layer, an adhesive layer, and a release layer. By utilizing the conductivity of the FeNi metal layer and the high permeability and magnetic loss characteristics of the composite magnetic nanoparticle layer, full-band electromagnetic shielding is achieved, especially with excellent shielding effects for low frequencies and static magnetic fields. Furthermore, the tape is designed with flexible materials to adapt to complex surfaces.
It achieves full-band electromagnetic shielding, especially high-efficiency shielding under low frequency and static magnetic field conditions, and the material is lightweight, adaptable to various complex surfaces, filling the gap in existing technology.
Smart Images
Figure CN122104073A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electromagnetic shielding materials technology, and particularly relates to an electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer and its preparation method. Background Technology
[0002] With the development of modern technology and the widespread use of electronic devices, the frequency, digitalization, and integration of electronic devices are constantly increasing. Electromagnetic energy radiated into the environment forms electromagnetic interference (EMI), which has become a form of environmental pollution. This not only affects the normal operation of electronic devices but may also harm human health. Therefore, electromagnetic shielding technology has emerged to block the propagation path of electromagnetic waves and reduce interference and radiation.
[0003] Currently, traditional electromagnetic shielding materials mainly include metal foils, metal meshes, and conductive coatings. While these materials achieve partial shielding effects due to their good conductivity, they exhibit significant drawbacks in practical applications. These materials primarily reflect electromagnetic waves and have limited absorption capabilities, making them unsuitable for high-frequency electromagnetic shielding. Furthermore, their shielding effectiveness decreases drastically in static and low-frequency magnetic field environments. In addition, these materials suffer from drawbacks such as heavy weight, susceptibility to corrosion, and poor flexibility, severely limiting their application in specialized fields such as wearable devices and aerospace.
[0004] Adhesive tape is an indispensable tool in daily life and work, serving both fixing and shielding functions. Electromagnetic shielding tape, as a new type of functional tape, is widely used in the electronic equipment manufacturing field due to its ease of use and flexible application. Existing electromagnetic shielding tapes (such as CN213506712U, CN110240874B, CN118667458B, etc.) are typically made by coating conductive or metallized base tape with adhesive, using conductive materials such as metal fibers and copper foil to block the propagation of electromagnetic waves. Although electromagnetic shielding tape can effectively shield high-frequency electromagnetic waves and electrostatic fields, its shielding effect on low-frequency and static magnetic fields may be less than ideal.
[0005] Magnetic nanomaterials have attracted widespread attention due to their excellent electromagnetic properties. Magnetic nanomaterials not only possess high permeability and magnetic loss, but their electromagnetic shielding performance can also be optimized by adjusting their composition and structure. By combining magnetic nanomaterials with conductive polymers such as polypyrrole (PPy) and polyaniline (PANI), composite magnetic nanomaterials with conductivity, magnetic loss characteristics, and high permeability can be prepared. These composites are applied to meet the requirements of full-band electromagnetic shielding, especially the challenges of shielding static magnetic fields and low-frequency magnetic fields (e.g., CN108447643A, CN118667458A).
[0006] However, research on electromagnetic shielding tapes specifically designed for full-frequency electromagnetic shielding, particularly low-frequency and static magnetic field shielding, is still relatively lacking in special environments. Summary of the Invention
[0007] The purpose of this invention is to address the shortcomings of the prior art by providing an electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer and its preparation method. This tape has excellent electromagnetic shielding performance across the entire frequency band, especially at low frequencies or in static magnetic fields, as well as good flexibility and corrosion resistance. It can effectively solve the shortcomings of existing electromagnetic shielding materials and meet the development needs of miniaturization and personalization of electronic devices.
[0008] The technical solution of this invention is: An electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer, comprising, from top to bottom: a protective layer, a FeNi metal layer, a composite electromagnetic nanoparticle layer, an adhesive layer, and a release layer; The composite magnetic nanoparticle layer is a 10-30 μm thick particle layer formed by combining a conductive polymer matrix and soft magnetic nanoparticles; the conductive polymer matrix is PPy or PANI, and the soft magnetic nanoparticles are Fe3O4 nanoparticles or CoFe nanoparticles.
[0009] Furthermore, the protective layer is made of any one of polyethylene terephthalate film, polyimide film, or polypropylene film, with a thickness of 5-20 μm. The function of the protective layer is to protect the FeNi metal layer from external environmental corrosion and mechanical damage, thereby improving the service life of the tape.
[0010] Furthermore, the FeNi metal layer is produced using a cold rolling process, with heat treatment to improve its magnetic permeability, and its thickness is 5-30 μm. The FeNi metal layer has good electrical conductivity and magnetic permeability, and can effectively shield low-frequency electric fields and some high-frequency electromagnetic waves, making it one of the main functional layers for electromagnetic shielding in tape.
[0011] Furthermore, the Fe3O4 or CoFe nanoparticles have a particle size of 5-50 nm, and the PPy or PANI coating thickness is 5-30 nm. This composite particle layer (10-30 μm thick) utilizes the high permeability and magnetic loss of Fe3O4 or CoFe and the conductive loss of PPy or PANI to achieve impedance matching, broaden the absorption frequency band, and effectively absorb electromagnetic waves, thereby improving the electromagnetic shielding effectiveness of the tape.
[0012] Furthermore, the adhesive layer uses an acrylic adhesive with a thickness of 10-30 μm. The function of the adhesive layer is to firmly adhere the tape to the surface of the object being shielded.
[0013] Furthermore, the release layer is made of silicone paper or release film, with a thickness of 20-50 μm. The function of the release layer is to protect the adhesive layer before the tape is used, preventing it from being contaminated or oxidized.
[0014] A method for preparing an electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer includes the following steps: Includes the following steps: S100, used to prepare composite electromagnetic nanoparticles; Soft magnetic nanoparticles (Fe3O4 nanoparticles or CoFe nanoparticles) were prepared by high-temperature pyrolysis, and a conductive polymer matrix (PPy or PANI) was coated on the surface of the soft magnetic nanoparticles by in-situ polymerization. Alternatively, conductive polymer-based nanotubes (PPy or PANI tubes) can be prepared, with soft magnetic nanoparticles loaded onto the conductive polymer-based nanotubes. S200, to prepare a composite electromagnetic nanoparticle layer; The composite electromagnetic nanoparticles prepared by S100 were added to an appropriate amount of acetone solvent and ultrasonically dispersed to obtain a magnetic composite particle dispersion. The dispersion was coated onto the surface of a 5-30 μm FeNi metal layer and dried at 60-80℃ to form a composite electromagnetic nanoparticle layer with a thickness of 10-30 μm. S300, the adhesive layer is laminated on the composite electromagnetic nanoparticle layer; An acrylic adhesive is coated onto the surface of a composite electromagnetic nanoparticle layer and dried at 60-100℃ to form an adhesive layer with a thickness of 10-30μm. S300, a composite of protective layer and release layer; A thin layer of adhesive is coated on the other side of the FeNi metal layer, and then a protective layer is adhered to the FeNi metal layer and pressed firmly. A release layer is then adhered to the surface of the adhesive layer and pressed firmly to obtain an electromagnetic shielding tape based on a composite electromagnetic material.
[0015] The beneficial effects of this application are as follows: First, existing electromagnetic shielding tapes are effective in electrostatic and high-frequency electromagnetic shielding, but less effective in magnetic shielding against low frequencies and static magnetic fields.
[0016] To address the need for full-band electromagnetic shielding, especially the challenge of static magnetic field shielding, a design is proposed that embed a composite magnetic nanoparticle layer within a FeNi layer electromagnetic shielding tape. The FeNi layer provides electromagnetic shielding for both low-frequency and static magnetic fields, based on the principle of magnetic circuit shunting. Utilizing the high permeability and low magnetic reluctance of ferromagnetic materials, the magnetic field is bypassed and shunted. The relatively high permeability of the ferromagnetic material forms a low magnetic reluctance path, allowing the vast majority of magnetic field lines to pass through the magnetic shielding structure, while the magnetic flux entering the shielded area is relatively small, thus achieving the purpose of magnetic shielding.
[0017] The magnetic shielding performance of magnetic shielding materials is generally judged by the magnetic shielding coefficient S and the magnetic shielding effectiveness SE value, calculated using the following formula: S=H0 / H 1， SE = 20logS, H0 represents the magnetic field strength before shielding, i.e., the original magnetic field strength without the installation of magnetic shielding material. H1 represents the magnetic field strength after shielding, i.e., the remaining magnetic field strength after the installation of magnetic shielding material.
[0018] For a single-layer shielding material with an inner radius of R1, when the relative permeability of the shielding material is sufficiently large and the thickness d of the shielding layer is very small, the magnetic shielding coefficient S can be expressed as: S = H0 / H1 ≈ 1 + 2μ r d / (3R1) μ r The relative permeability of a shielding material is the ratio of its absolute permeability μ to the vacuum permeability μ0.
[0019] The FeNi layer can be made of permalloy 1J85 material, and through annealing, the relative magnetic permeability μ is achieved. r With a conductivity exceeding 50,000, the FeNi layer exhibits good shielding effects against static magnetic fields and low-frequency magnetic fields. Composite magnetic nanomaterials, leveraging their high electrical conductivity and magnetic permeability, achieve effective impedance matching and electromagnetic loss characteristics, enabling highly efficient electromagnetic shielding and absorption against both high-frequency and low-magnetic fields.
[0020] This application incorporates FeNi layers and composite nanoparticles into the tape, retaining the tape's flexibility and slight bendability, enabling it to tightly adhere to irregular surfaces. This provides an efficient shielding solution for complex structures, especially in low-frequency and static magnetic field environments, filling a gap in existing technologies.
[0021] The tape of this invention combines the magnetic permeability of the FeNi metal layer with the conductive and magnetic losses and characteristics of the composite magnetic material layer (a combination of high-permeability soft magnet and conductive polymer). It can simultaneously reflect and absorb electromagnetic waves, and the magnetic permeability guiding mechanism provides excellent electromagnetic shielding performance over a wide frequency range, especially in low-frequency and static magnetic fields.
[0022] Secondly, the present invention uses soft magnetic nanoparticles coated with conductive polymers in different proportions. The proportion of soft magnetic nanoparticles is adjustable from 10% to 60%, which can yield electromagnetic shielding tapes for different frequency ranges.
[0023] Third, the tape of the present invention uses an extremely thin FeNi metal layer and a composite magnetic material layer, which has good flexibility and bendability and can adapt to various complex application scenarios.
[0024] Fourth, compared with traditional metal shielding materials, the tape of the present invention uses a composite magnetic material layer that combines high permeability soft magnets and conductive polymers, which greatly reduces the weight of the material while ensuring electromagnetic shielding performance, thus conforming to the development trend of lightweight electronic equipment. Attached Figure Description
[0025] The present invention will be further described in detail below with reference to the embodiments shown in the accompanying drawings, but this does not constitute any limitation on the present invention.
[0026] Figure 1 This is a schematic diagram of the electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer in this invention.
[0027] Figure 2 This is a particle image of Fe3O4 / PPy in this invention (PPy encapsulates Fe3O4 particles).
[0028] Figure 3 This is a particle image of Fe3O4 / PPy in this invention (Fe3O4 particles loaded on the surface of PPy nanotubes).
[0029] Figure 4 This is a graph showing the electromagnetic wave reflection loss of PPy / CoFe in this invention as a function of frequency.
[0030] The annotations in the attached figures are explained as follows: 1-Protective layer; 2-FeNi metal layer; 3-Composite electromagnetic nanoparticle layer; 4-Adhesive layer; 5-Release layer. Detailed Implementation
[0031] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto. Example 1
[0032] The preparation of electromagnetic shielding tape based on composite electromagnetic nanoparticle layers includes the following steps: 1.1 Preparation of PPy / Fe3O4 composite particles Fe3O4 nanoparticles were prepared by hydrothermal synthesis. 0.706 g of Fe(acac)3 (2 mmol) was weighed and added to a beaker, followed by 2.4 mL of oleic acid and 38 mL of ethanol. The mixture was vigorously stirred with a magnetic stirrer for 10 minutes. The homogeneous solution was poured into a 50 mL polytetrafluoroethylene-lined reactor and reacted in a forced-air drying oven at 180 °C for 12 h. After the reaction, the reactor was allowed to cool to room temperature. The precipitate was collected in n-hexane. Excess ethanol was added and the mixture was centrifuged (8000 rpm, 5 min). The supernatant was removed, and the precipitate was retained. The nanoparticles were redissolved in n-hexane, and this process was repeated three times. The nanoparticles were then dried in a vacuum drying oven (50 °C, 4 h) to obtain oil-phase Fe3O4 nanoparticles.
[0033] 0.2 g of Fe3O4 nanoparticles were added to 80 mL of deionized water, along with 0.2 g of sodium dodecylbenzenesulfonate and 0.3 g of polyvinylpyrrolidone. The mixture was sonicated for 30 min and then stirred for 2 h to ensure homogeneity. 0.60 mL of pyrrole monomer was added, and after 30 min, 600 mg of FeCl3 was added dropwise. After reacting for 12 h, the product was centrifuged in a centrifuge tube, and the precipitate was collected. The precipitate was dried in a vacuum drying oven at 80 °C for 4 h. By adjusting the mass percentage of Fe3O4 nanoparticles and pyrrole monomer, PPy / Fe3O4 composite particles with different mass percentages of Fe3O4 nanoparticles were prepared: 20%, 30%, 40%, 50%, and 60%.
[0034] 1.2 Preparation of PPy / Fe3O4 composite particle layer Add 5 ml of acetone and ultrasonically disperse for 30 minutes to obtain a PPy / Fe3O4 composite particle dispersion. Coat the composite particle dispersion uniformly onto the surface of a 10 μm thick FeNi metal layer and dry at 80℃ for 2 hours to form a 20 μm thick magnetic composite particle layer. The FeNi metal layer is prepared by cold rolling of strip. The heat treatment process is as follows: heat to 1150℃ and hold for 3 hours in a hydrogen furnace, cool to 950℃ and hold for 3 hours, continue cooling to 400℃ in the furnace, and then rapidly cool to room temperature after removal from the furnace.
[0035] 1.3 Preparation of the adhesive layer Add 10g of acrylic adhesive to 5mL of toluene and stir until homogeneous to obtain an adhesive coating. Coat the coating evenly on the surface of the magnetic composite particle layer and dry at 80℃ for 1h to form an adhesive layer with a thickness of 20μm.
[0036] 1.4, Composite of protective layer and release layer A thin layer of polyurethane adhesive is coated on the other side of the FeNi metal layer, and then a 12μm thick PET film is bonded to the FeNi metal layer and compacted.
[0037] A 38μm thick silicone paper is laminated onto the surface of the adhesive layer and pressed firmly to form a release layer. This results in an electromagnetic shielding tape based on electromagnetic composite nanomaterials. Example 2
[0038] 2.1 Preparation of PANI / CoFe composite particles In a four-necked flask filled with argon gas, 1.0 mmol FeCl2·4H2O and 20 mL diphenyl ether were added sequentially. After purging the flask with an oil pump to remove air, argon gas was continuously introduced for 30 min. Then, 3.0 mmol triphenylphosphine was added, and the system was heated to 100 °C. Next, 1.0 mmol oleic acid was added, and the temperature was further increased to 260 °C. 2.5 mL of 1M tetrahydrofuran solution of LiHBEt3 was slowly added dropwise using a glass syringe. Once the temperature returned to 260 °C, 1.0 mmol Co2(CO)8 dissolved in 10 mL diphenyl ether was added dropwise while rapidly stirring to mix. The reaction system was refluxed under argon gas for 30 min, cooled to room temperature, and then ethanol was added. The mixture was centrifuged at 8000 rpm for 5 min, the supernatant was discarded, and the precipitate was retained. The precipitate was purified three times by redissolving in hexane and precipitating with ethanol. Finally, it was annealed at 500 °C under vacuum for 40 min to successfully prepare CoFe nanoparticles.
[0039] 0.2 g of CoFe nanoparticles were dispersed in 50 mL of HCl (0.1 mol / L) solution and ultrasonically dispersed. The solution was then placed in an ice bath. 0.3 mL of aniline was slowly added to the solution, and the mixture was stirred until uniformly dispersed. Then, 0.2 g of oxidant (NH₄)₂SO₄ was weighed and added to 20 mL of HCl (0.1 mol / L) solution. After uniform dispersion, the oxidant was added dropwise to initiate the polymerization reaction. The mixture was kept in an ice bath for 4 h, then sealed and placed in a refrigerator for 24 h. After the reaction was complete, the mixture was washed three times alternately with deionized water and ethanol, and then dried in a vacuum drying oven at 60 °C for 12 h to obtain PANI / CoFe composite particles.
[0040] The preparation and lamination of the adhesive layer, protective layer and release layer are the same as in Example 1.
[0041] The above-described embodiments are preferred embodiments of the present invention and are only used to facilitate the illustration of the present invention. They are not intended to limit the present invention in any way. Any person skilled in the art who makes partial changes or modifications to the technical content disclosed in the present invention without departing from the scope of the technical features of the present invention shall still fall within the scope of the technical features of the present invention.
Claims
1. An electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer, characterized in that, From top to bottom: protective layer, FeNi metal layer, composite electromagnetic nanoparticle layer, adhesive layer and release layer; The composite magnetic nanoparticle layer is a 10-30 μm thick particle layer formed by combining a conductive polymer matrix and soft magnetic nanoparticles; the conductive polymer matrix is PPy or PANI, and the soft magnetic nanoparticles are Fe3O4 nanoparticles or CoFe nanoparticles.
2. The electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer according to claim 1, characterized in that, The protective layer is made of any one of polyethylene terephthalate film, polyimide film, or polypropylene film, with a thickness of 5-20 μm.
3. The electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer according to claim 1, characterized in that, The thickness of the FeNi metal layer is 5-30 μm.
4. The electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer according to claim 1, characterized in that, The Fe3O4 or CoFe nanoparticles have a particle size of 5-50 nm, and the PPy or PANI coating thickness is 5-30 nm.
5. The electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer according to claim 1, characterized in that, The adhesive layer is made of acrylate adhesive and has a thickness of 10-30 μm.
6. The electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer according to claim 1, characterized in that, The release layer is made of silicone paper or release film, and its thickness is 20-50μm.
7. A method for preparing an electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer, characterized in that, Includes the following steps: Includes the following steps: S100, used to prepare composite electromagnetic nanoparticles; Soft magnetic nanoparticles were prepared by high-temperature pyrolysis and then composite magnetic nanoparticles were formed by coating a conductive polymer matrix onto the surface of the soft magnetic nanoparticles using in-situ polymerization. Alternatively, conductive polymer-based nanotubes (PPy or PANI tubes) can be prepared, with soft magnetic nanoparticles loaded onto the conductive polymer-based nanotubes. S200, to prepare a composite electromagnetic nanoparticle layer; The composite electromagnetic nanoparticles prepared by S100 were added to an appropriate amount of acetone solvent and ultrasonically dispersed to obtain a magnetic composite particle dispersion. The dispersion was coated onto the surface of a 5-30 μm FeNi metal layer and dried at 60-80℃ to form a composite electromagnetic nanoparticle layer with a thickness of 10-30 μm. S300, the adhesive layer is laminated on the composite electromagnetic nanoparticle layer; An acrylic adhesive is coated onto the surface of a composite electromagnetic nanoparticle layer and dried at 60-100℃ to form an adhesive layer with a thickness of 10-30μm. S300, a composite of protective layer and release layer; A thin layer of adhesive is applied to the other side of the FeNi metal layer, and then the protective layer is attached to the FeNi metal layer and pressed firmly. A release layer is bonded to the surface of the adhesive layer and compacted to obtain an electromagnetic shielding tape based on composite electromagnetic materials.
8. The method for preparing an electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer according to claim 7, characterized in that, The soft magnetic nanoparticles are Fe3O4 nanoparticles or CoFe nanoparticles, and the conductive polymer matrix is PPy or PANI.
9. A method for preparing an electromagnetic shielding tape based on a composite electromagnetic nanoparticle layer according to claim 7, characterized in that, The thickness of the composite magnetic nanoparticle layer is 10-30 μm.