Magnetic composite material, magnetic member, and device for wireless power supply

Abstract

To improve vibration resistance in a magnetic composite material.SOLUTION: A magnetic composite material includes a resin material, and a soft magnetic body contained in the resin material, wherein a loss coefficient tanδ by dynamic viscoelasticity measurement at a frequency of 1 Hz to 110 Hz at room temperature is 0.05 or more, and a real part μ' of complex relative permeability in a frequency region of 50 kHz to 100 kHz is 5 or more.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to magnetic composite materials. [Background technology]

[0002] Conventionally, Litz wire or plate-shaped coils have been used for wireless power supply coils used in electric vehicles, and studies have been conducted to reduce AC resistance and achieve highly efficient power transmission. For example, in the technology described in Patent Document 1, an adhesive layer is provided on the outer surface of a conductor used in the coil, and a magnetic powder layer is provided in which magnetic powder is fixed by the adhesive layer. In addition, in the technology described in Non-Patent Document 1, a magnetic composite material (also called a magnetic composite material) in which magnetic particles are blended with a silicone resin is used to form a magnetic layer on the surface of a plate-shaped coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-018585 [Non-patent literature]

[0004] [Non-Patent Document 1] Shun Endo, Takahiro Kasai, Takeshi Utsubo, Tsutomu Mizuno, "Lightweight and Efficient Wireless Power Transfer Coils Using Magnetically Coated Aluminum Plates," IEICE Technical Report, vol.117, no.383, WPT2017-66(2018-01), pp.59-64 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a device such as a wireless power supply system using a coil coated with a magnetic composite material obtained by combining a resin material and a magnetic body as described in Patent Document 1 and Non-Patent Document 1 is installed in an electric vehicle or the like as a battery power supply device, there is a possibility that cracks will occur in the magnetic layer, or that interfacial peeling will occur between the magnetic layer and the coil, etc. Therefore, there has been a demand for improved vibration resistance in magnetic composite materials.

[0006] Such issues related to vibration resistance are not limited to cases where a magnetic layer is formed on the surface of a coil using a magnetic composite material or where a magnetic composite material is used for a wireless power supply device, but are common issues when using an object made of a magnetic composite material in an environment affected by vibration. [Means for solving the problem]

[0007] The present disclosure can be realized in the following forms. (1) According to one embodiment of the present disclosure, there is provided a magnetic composite material comprising a resin material and a soft magnetic body contained in the resin material, and having a loss factor tanδ of 0.05 or greater as measured by dynamic viscoelasticity measurement at room temperature in a frequency range of 1 Hz to 110 Hz, and a real part μ′ of complex relative permeability of 5 or greater in a frequency range of 50 kHz to 100 kHz.

[0008] According to the magnetic composite material of this embodiment, the loss factor tan δ measured by dynamic viscoelasticity measurement at room temperature in the frequency range of 1 Hz to 110 Hz is large, at 0.05 or more, and therefore when an article made of this magnetic composite material is subjected to vibrations at a frequency of about 1 Hz to 110 Hz, the impact absorption ability of the article made of this magnetic composite material can be ensured. Therefore, for example, when a magnetic layer is formed using this magnetic composite material, damage to the magnetic layer due to impact from the vibrations and damage to electronic devices and the like arranged adjacent to a component having the magnetic layer due to damage to the magnetic layer can be suppressed.

[0009] Furthermore, since the real part μ' of the complex relative permeability in the frequency range of 50 kHz to 100 kHz is high at 5 or more, the degree to which the magnetic composite material can retain the magnetic field can be improved. For example, if a magnetic layer is formed on the surface of a coil using this magnetic composite material, the magnetic field lines can be converged around the coil in the frequency range of 50 kHz to 100 kHz, and magnetic field leakage can be suppressed. Furthermore, if a coil is covered with this magnetic composite material, the magnetic field can be confined around the coil without being eliminated. When a coil is covered with this magnetic composite material, it is possible to achieve reduced AC resistance and improved power transmission efficiency.

[0010] (2) In the magnetic composite material of the above embodiment, the storage modulus, as determined by dynamic viscoelasticity measurement at room temperature in a frequency range of 1 Hz to 110 Hz, may be 200 MPa or less. The lower the storage modulus, the more flexible the magnetic composite material is, and the more difficult it is to preserve (storage) energy in response to displacement in the magnetic composite material. Therefore, by adopting such a configuration, it is possible to prevent the stored energy from being converted into repulsive energy, etc., and to improve the impact absorption capacity of the magnetic composite material.

[0011] (3) The magnetic composite material of the above embodiment may have an elongation of 30% or more at room temperature. This configuration ensures the flexibility and deformability of the magnetic composite material. For example, even when the magnetic composite material is used by being layered with a member having a significantly different thermal expansion coefficient from that of the magnetic composite material, the magnetic composite material can easily follow the thermal expansion of such a member.

[0012] (4) In the magnetic composite material of the above embodiment, the rubber hardness measured with a Type A durometer defined in JIS K 6235-3:2012 may be equal to or less than 80. With this configuration, the degree to which the magnetic composite material can flexibly deform in response to an impact increases, thereby improving the impact absorption capacity of the magnetic composite material.

[0013] (5) In the magnetic composite material of the above aspect, the soft magnetic body may contain at least one of a metal and a ferrite, which makes it easier to ensure the function of the magnetic composite material as a magnetic body.

[0014] (6) In the magnetic composite material of the above aspect, the resin material may be silicone rubber, which makes it easier to ensure the heat resistance, flexibility, adhesiveness, and weather resistance of the magnetic composite material.

[0015] (7) In the magnetic composite material of the above embodiment, the peak of the imaginary part μ″ of the complex relative permeability may be 150 kHz or higher. With this configuration, when a device including the magnetic composite material is used in a frequency range of, for example, 50 kHz to 100 kHz, the effect of suppressing magnetic loss of the magnetic composite material can be enhanced.

[0016] (8) In the magnetic composite material of the above embodiment, the imaginary part μ″ of the complex relative permeability in the frequency range of 50 kHz to 100 kHz may be 2.0 or less. With this configuration, the magnetic loss of the magnetic composite material in the above frequency band can be suppressed.

[0017] (9) In the magnetic composite material of the above embodiment, the shear adhesive strain with respect to the aluminum plate may be 20% or more. With this configuration, it is possible to ensure bonding with, for example, an aluminum coil.

[0018] (10) According to another aspect of the present disclosure, there is provided a magnetic member including a planar coil formed by spirally winding a wire material, and a covering made of the magnetic composite material of the above aspect that covers the planar coil. By providing the covering made of the magnetic composite material of this aspect, the magnetic member can have improved vibration resistance and can also converge magnetic lines of force around the planar coil.

[0019] (11) According to yet another aspect of the present disclosure, there is provided a wireless power supply device including: a planar coil formed by spirally wound wire; a covering made of the magnetic composite material of the above aspect and covering the planar coil; and a circuit board electrically connected to the planar coil for supplying AC power to the planar coil or for supplying power generated by the planar coil to a load.

[0020] According to this form of wireless power supply device, by providing a covering made of the above-mentioned magnetic composite material, the vibration resistance of the wireless power supply device can be improved and the magnetic lines of force can be converged around the planar coil.

[0021] The present disclosure can be realized in various forms other than those described above, such as a method for manufacturing a magnetic composite material, a wireless power supply method using a magnetic composite material, a vehicle using a magnetic composite material, or a mobile body using a magnetic composite material. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is an explanatory diagram showing a schematic configuration of a magnetic member according to the embodiment. [Figure 2] 1 is a cross-sectional view illustrating a schematic configuration of a magnetic composite material according to an embodiment. [Figure 3] 1 is a cross-sectional schematic diagram showing a magnetic composite material including soft magnetic material particles having a spherical shape. [Figure 4] 1 is a cross-sectional schematic diagram showing a magnetic composite material including soft magnetic material particles having a flat particle shape. [Figure 5] FIG. 1 is an explanatory diagram schematically illustrating a configuration of a wireless power feeding system. [Figure 6] FIG. 3 is an explanatory diagram schematically showing the arrangement of two magnetic members. [Figure 7] FIG. 10 is a cross-sectional view illustrating the operation of wireless power supply. [Figure 8] FIG. 2 is an explanatory diagram illustrating the specific configuration of a magnetic sheet. [Figure 9] FIG. 10 is an explanatory diagram showing the measured values relating to the performance of each sample. [Figure 10] FIG. 10 is an explanatory diagram showing a summary of evaluation results for the magnetic composite material. [Figure 11] FIG. 3 is an explanatory diagram showing the loss factor tan δ at frequencies of 0.1 Hz to 110 Hz. [Figure 12] FIG. 1 is an explanatory diagram showing values of storage modulus at frequencies of 0.1 Hz to 110 Hz. [Figure 13] FIG. 10 is an explanatory diagram schematically showing a method for calculating shear adhesive strain. DETAILED DESCRIPTION OF THE INVENTION

[0023] FIG. 1 is an explanatory diagram showing a schematic configuration of a magnetic member 41 according to an embodiment of the present disclosure. FIG. 1(A) shows a planar configuration, and FIG. 1(B) shows a cross-sectional configuration of portion X in FIG. 1(A). As shown in the figure, the magnetic member 41 includes a planar coil 42 in which a wire is wound in a spiral shape and a covering portion 16 that covers the planar coil 42. The planar coil 42 is a plate-shaped coil formed of a metal such as aluminum or copper. The covering portion 16 is formed of a magnetic composite material 10 (described later) and covers the planar coil 42. As shown in FIG. 1(B), the magnetic composite material 10 is filled between adjacent wires. If the magnetic composite material 10 is not filled between adjacent wires and air is introduced, the state of the magnetic field may change, potentially resulting in magnetic field leakage. However, this configuration can suppress magnetic field leakage and reduce a decrease in power transmission efficiency. In other embodiments, a litz wire coil may be used. However, the use of a planar coil (also called a plate-type coil) can contribute to weight reduction, thickness reduction, high efficiency of power transmission, and reduction of AC resistance of the coil.

[0024] FIG. 2 is an explanatory diagram showing a schematic configuration of a magnetic composite material 10 according to an embodiment of the present disclosure. The magnetic composite material 10 includes a resin material 12 and a soft magnetic material 14 contained in the resin material 12. In the magnetic composite material 10 of this embodiment, the soft magnetic material 14 is dispersed in the resin material 12 in the form of powder particles. As will be described later, the magnetic composite material 10 of this embodiment is characterized by its excellent vibration resistance (impact resistance). The overall configuration of the magnetic composite material 10 will be described below.

[0025] The resin material 12 preferably has vibration absorption properties by itself, and examples thereof include elastomers such as natural rubber, butyl rubber, nitrile rubber, silicone rubber, polyurethane, and fluorine-based rubber. Among these, silicone rubber is particularly preferred due to its ease of mixing with the soft magnetic material 14 (filler) and its high heat resistance, weather resistance, and adhesive properties. When silicone rubber is used as the resin material 12, the molecular weight between crosslinking points of the silicone rubber is preferably 20,000 or more in order to optimize the elongation and rubber hardness of the magnetic composite material 10. Using an elastomer as the resin material 12 can improve flexibility compared to using polycarbonate, polypropylene, epoxy resin, or phenolic resin. Furthermore, it can improve heat resistance and weather resistance compared to urethane. Resin materials other than elastomers may also be used as the resin material 12. For example, using polycarbonate or polypropylene can result in a magnetic composite material 10 with excellent shape stability, using urethane can result in a magnetic composite material 10 with excellent vibration absorption ability, and using epoxy resin or phenolic resin can result in a magnetic composite material 10 with excellent adhesiveness.

[0026] It is desirable that the soft magnetic material 14 be practical as a magnetic material in a frequency range of, for example, 50 to 100 kHz. This allows the magnetic composite material 10 to be suitably used in wireless power supply devices, as described below. The frequency range of 50 to 100 kHz is a frequency range in which high power transmission efficiency can be achieved in wireless power supply. From the perspective of applying the magnetic composite material 10 to a wireless power supply device, it is desirable that the soft magnetic material 14 function well as a magnetic material, particularly in the 85 kHz band, which is the resonance frequency of magnetic field coupling type wireless power supply. The soft magnetic material 14 can include, for example, at least one of a soft magnetic metal and a soft magnetic ferrite. The inclusion of such a soft magnetic material 14 allows the magnetic composite material 10 to function as a good magnetic material.

[0027] Examples of soft magnetic metals that constitute the soft magnetic body 14 include Fe-Si alloys, Fe-Si-Cr alloys, sendust (Fe-Si-Al alloys), and permalloy (Fe-Ni alloys). Examples of ferrites that constitute the soft magnetic body 14 include Ni-Zn ferrite (nickel zinc ferrite) and Mn-Zn ferrite (manganese zinc ferrite). Among these soft magnetic materials, Ni-Zn ferrite and Mn-Zn ferrite are particularly preferred because they have a large real part μ' of their complex relative permeability in the frequency range of 50 kHz to 100 kHz. The larger the real part μ' of the complex relative permeability, the greater the degree to which magnetic flux can be confined.

[0028] Furthermore, the shape of the powder particles of the soft magnetic material 14 is preferably close to spherical, from the viewpoint of improving the vibration absorption properties of the magnetic composite material 10 as a whole. Specifically, the aspect ratio (major axis / minor axis) of the powder particles of the soft magnetic material 14 is preferably, for example, 5 or less, and more preferably 3 or less. Here, the "major axis" refers to the maximum value of the distance between two parallel lines when an image of a powder particle of the soft magnetic material 14 projected in the vertical direction is sandwiched between the two lines, and the "minor axis" refers to the minimum value of the distance between the two lines. The effect of the particle shape of the soft magnetic material 14 on the vibration and shock absorption by the magnetic composite material 10 will be further described below.

[0029] FIG. 3 is a cross-sectional schematic diagram of a magnetic composite material 10a including spherical soft magnetic particles 14a, and FIG. 4 is a cross-sectional schematic diagram of a magnetic composite material 10b including flat soft magnetic particles 14b. FIGS. 3 and 4 show an object 20 colliding with a sheet of each magnetic composite material, applying an impact to the magnetic composite material. Generally, when an impact is applied to a sheet made of an elastomer, the impact is absorbed by deformation of the elastomer. As shown in FIGS. 3 and 4, when an impact is applied to a sheet made of a magnetic composite material containing both an elastomer and a soft magnetic material (filler), the impact is absorbed by rearrangement of the filler and deformation of the resin material 12 present between the filler. After the impact, the sheet made of the magnetic composite material attempts to return to its original shape.

[0030] Here, when the filler has a nearly spherical shape as shown in Fig. 3, the filler that receives an impact can disperse the impact to other adjacent fillers, and as a result, the resin material 12 present around these fillers also deforms to a greater extent, making it easier to absorb a larger impact. In Fig. 3, the dashed arrows indicate how the impact is dispersed from the impacted filler to the surrounding fillers.

[0031] In contrast, when the filler has a flat shape, as shown in Figure 4, the filler behaves like a metal or ceramic plate upon impact. In Figure 4, the outline arrows indicate how the impact is transmitted within the magnetic composite material 10b. When the filler has a flat shape, the resin material 12 undergoes minimal deformation upon impact, and a portion of the applied impact is converted into a repulsive force, which remains as residual stress within the magnetic composite material sheet. Therefore, to enhance the impact resistance (vibration resistance) of the magnetic composite material 10, it is preferable that the particle shape of the soft magnetic material 14 be closer to spherical. As mentioned above, the degree to which an impact is converted into a repulsive force and the degree to which it remains as residual stress within the magnetic sheet increases with the increase in the storage modulus of the magnetic sheet. Therefore, even when using a flat soft magnetic material 14 as the filler, reducing the storage modulus of the magnetic sheet can ensure the impact resistance and vibration resistance of the magnetic sheet. The storage modulus of the magnetic composite material 10 will be described in detail later.

[0032] When the soft magnetic body 14 is made of metal and the particle shape of the soft magnetic body 14 is close to spherical, the particle size of the soft magnetic body 14 is preferably 10 μm or more from the viewpoint of increasing the real part μ' of the complex relative magnetic permeability. Then, from the viewpoint of shifting the peak of the imaginary part μ" of the complex relative magnetic permeability of the magnetic composite material 10 (described later) to the high frequency side, the particle size of the soft magnetic body 14 is preferably 50 μm or less, more preferably 45 μm or less, and even more preferably 40 μm or less. Furthermore, when the soft magnetic body 14 has a flat shape and, for example, an aspect ratio of more than 5, for the same reason as when the particle shape is spherical, the long side of the powder particle of the soft magnetic body 14 is preferably 20 μm or more, and the short side is preferably 1 μm or more. Then, the long side of the powder particle of the soft magnetic body 14 is preferably 150 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less. Furthermore, the short side of the powder particle of the soft magnetic body 14 is Preferably, the particle size is 10 μm or less, more preferably 9 μm or less, and even more preferably 8 μm or less. When the soft magnetic material 14 has a flat shape, the powder particles of the soft magnetic material 14 are oriented in the resin material 12. Therefore, in order to ensure the impact resistance (vibration resistance) as described above, and also to ensure the flexibility of the magnetic sheet, it is preferable that the powder particles of the soft magnetic material 14 have a particle shape close to spherical. When the soft magnetic material 14 is made of ferrite, unlike when the soft magnetic material 14 is made of metal, there is no preferred particle size range for the soft magnetic material 14 from the perspective of increasing the real component μ' of the complex relative permeability due to the high electrical resistance of ferrite. The particle size may be set to be smaller than the thickness of the member formed from the magnetic composite material 10.

[0033] Furthermore, the loss factor tan δ of magnetic composite material 10, measured by dynamic viscoelasticity measurement at room temperature in a frequency range of 1 Hz to 110 Hz (hereinafter simply referred to as "loss factor tan δ"), may be 0.05 or greater, and preferably 0.1 or greater. The value of the loss factor tan δ of magnetic composite material 10 can be expressed as, for example, the degree to which impact energy can be converted into other energy, and it can be said that the larger the loss factor tan δ, the higher the impact absorption ability of magnetic composite material 10. Therefore, by setting the value of the loss factor tan δ of magnetic composite material 10 within the above range, it is possible to prevent damage to magnetic composite material 10 and damage to electronic devices and the like adjacent to magnetic composite material 10 caused by damage to magnetic composite material 10 when vibrations of a frequency range of about 1 Hz to 110 Hz are applied.

[0034] In the magnetic composite material 10, the real part μ' of the complex relative magnetic permeability in the frequency range of 50 kHz to 100 kHz (hereinafter simply referred to as the "real part μ'") may be 5 or greater, more preferably 10 or greater, and even more preferably 20 or greater. It is particularly preferable that the real part μ' be constant around 85 kHz, which is the resonant frequency of magnetic field coupling-based wireless power transfer. This makes it possible to compensate for frequency fluctuations to a certain extent. The real part μ' of the complex relative magnetic permeability represents the performance of a magnetic material; the larger the real part μ', the stronger the magnetic field it can retain. By setting the real part μ' within the above range, the magnetic composite material 10 can function well as a magnetic material in the above frequency band and can confine magnetic flux. The value of this real part μ' can be adjusted by the type of soft magnetic material constituting the soft magnetic material 14, and can be increased by increasing the particle size of the soft magnetic material 14 or by increasing the amount of the soft magnetic material 14 added to the magnetic composite material 10. Furthermore, when soft magnetic material 14 having flat particle shapes is used in a sheet made of magnetic composite material 10, the soft magnetic material 14 is oriented and the long axis of the flat shape approaches parallel to the sheet surface, thereby increasing the real part μ' of magnetic composite material 10 in the plane parallel to the sheet surface. Furthermore, reducing the particle size of soft magnetic material 14 makes it possible to maintain a high value of real part μ' even in higher frequency bands.

[0035] In magnetic composite material 10, the storage modulus (hereinafter simply referred to as "storage modulus") measured by dynamic viscoelasticity measurement at room temperature in a frequency range of 1 Hz to 110 Hz is preferably 200 MPa or less, more preferably 100 MPa or less, and even more preferably 50 MPa or less. The storage modulus is a parameter that indicates the hardness that contributes to the shock absorption capacity of magnetic composite material 10, which is a viscoelastic body. To ensure the shock absorption capacity of magnetic composite material 10, a lower storage modulus is desirable. In other words, the lower the storage modulus, the more flexible magnetic composite material 10 is, and the more difficult it is for magnetic composite material 10 to preserve (storage) energy in response to displacement. Furthermore, since the energy stored in magnetic composite material 10 leads to repulsion energy in response to impact, a lower storage modulus can be said to enhance the shock absorption capacity of magnetic composite material 10.

[0036] It is desirable that the magnetic composite material 10 has an elongation rate (hereinafter simply referred to as "elongation rate") of 30% or more at room temperature. This ensures the flexibility of the magnetic composite material 10. By ensuring the flexibility and deformability of the magnetic composite material 10, for example, when the magnetic composite material 10 is used integrated with a member having a large thermal expansion coefficient, such as a metal member (for example, when the magnetic composite material 10 is integrated with a coil to form a magnetic member as described below), the magnetic composite material 10 can easily follow the thermal expansion of the metal member when the temperature rises.

[0037] In the magnetic composite material 10, the rubber hardness (hereinafter simply referred to as "rubber hardness") measured with a Type A durometer specified in JIS K 6235-3:2012 is preferably 80 or less, more preferably 70 or less, and even more preferably 60 or less. The rubber hardness is one of the parameters that indicates the hardness that contributes to the shock absorption ability of the magnetic composite material 10, which is an elastic body. The lower the rubber hardness, the more flexibly the magnetic composite material 10 can deform in response to an impact, so a lower rubber hardness is desirable in order to ensure the shock absorption ability of the magnetic composite material 10. However, if the rubber hardness of the magnetic composite material 10 is excessively low, the magnetic composite material 10 may lack strength, so the rubber hardness is preferably 10 or more.

[0038] The loss factor tanδ, storage modulus, rubber hardness, elongation, and shear bond strain of the magnetic composite material 10 described above can be adjusted, for example, by the crosslink density of the resin material 12, the molecular weight of the resin material 12, the amount of soft magnetic material 14 added to the magnetic composite material 10, and the particle shape of the soft magnetic material 14. For example, lowering the crosslink density of the resin material 12 tends to increase the loss factor tanδ, elongation, and shear bond strain, and tend to decrease the storage modulus and rubber hardness. Increasing the molecular weight between crosslink points of the resin material 12 tends to increase the loss factor tanδ, elongation, and shear bond strain, and tend to decrease the storage modulus and rubber hardness. In addition, reducing the amount of soft magnetic material 14 added to the magnetic composite material 10 tends to increase the loss factor tanδ, elongation, and shear bond strain, and tend to decrease the storage modulus and rubber hardness. However, reducing the amount of soft magnetic material 14 added to magnetic composite material 10 reduces the magnetic properties of magnetic composite material 10, and therefore, reducing the amount of soft magnetic material 14 added is undesirable from the viewpoint of ensuring the magnetic properties of magnetic composite material 10. Furthermore, the closer the particle shape of soft magnetic material 14 is to a sphere, the greater the loss factor tan δ, elongation, and shear adhesive strain tend to be, and the greater the storage modulus and rubber hardness tend to be.

[0039] In the magnetic composite material 10, the imaginary part μ" of the complex relative permeability in the frequency range of 50 kHz to 100 kHz (hereinafter also referred to simply as "imaginary part μ") is preferably 2.0 or less, more preferably 1.0 or less, and even more preferably 0.5 or less. In this way, by suppressing the imaginary part μ" of the complex relative permeability, it is possible to suppress magnetic loss in the magnetic composite material 10. Therefore, for example, when the magnetic composite material 10 is applied to a wireless power supply device as described below and made to function as a transformer component in the frequency range of 50 kHz to 100 kHz, it is possible to increase the power supply efficiency of the wireless power supply device by suppressing magnetic loss.

[0040] In such a magnetic composite material 10, the peak of the imaginary part μ" is desirably 150 kHz or higher. With such a configuration, when a device including the magnetic composite material 10 is used in a frequency range of 50 kHz to 100 kHz, for example, the effect of suppressing magnetic loss of the magnetic composite material 10 can be enhanced. The peak of the imaginary part μ" can be shifted to the higher frequency side by reducing the particle size of the soft magnetic body 14 or by covering the powder particles of the soft magnetic body 14 with a resin. In addition, increasing the degree of dispersion of the powder particles of the soft magnetic body 14 in the magnetic composite material 10 can also contribute to shifting the peak of the imaginary part μ". The imaginary part μ" of the complex relative permeability represents loss, and is small near 85 kHz, which is the resonance frequency of magnetic field coupling type wireless power transfer, and it is preferable that the peak position is shifted from 85 kHz. This is because the presence of an imaginary component reduces the magnetic flux.

[0041] The magnetic composite material 10 preferably has a shear adhesive strain of 20% or more, and more preferably 30% or more, relative to the aluminum plate. The larger the shear adhesive strain, the stronger the adhesiveness of the magnetic composite material 10 to the aluminum plate. As shown in FIG. 1, when the magnetic composite material 10 is used to form a magnetic member 41, the adhesiveness with a planar coil 42 containing aluminum as a main component can be ensured. The shear adhesive strain can be increased by using, for example, adhesive silicone rubber as the resin material 12.

[0042] The magnetic composite material 10 of this embodiment configured as described above has a loss factor tanδ of 0.05 or greater as determined by dynamic viscoelasticity measurement at room temperature in the frequency range of 1 Hz to 110 Hz. This ensures that a component (e.g., the coating 16 shown in FIG. 1 ) made of the magnetic composite material 10 can maintain its shock absorption capacity when subjected to vibrations at frequencies of approximately 1 Hz to 110 Hz. This prevents damage to the component made of the magnetic composite material 10 due to impact from the vibrations, and prevents damage to electronic devices or other devices adjacent to the component made of the magnetic composite material 10 due to damage to the component made of the magnetic composite material 10. Furthermore, the magnetic composite material 10 of this embodiment has a high real part μ′ of the complex relative permeability of 5 or greater in the frequency range of 50 kHz to 100 kHz, thereby improving the degree to which the magnetic composite material 10 can retain a magnetic field. For example, when this magnetic composite material 10 is used to coat a coil, the magnetic field can be confined around the coil without being eliminated in the frequency range of 50 kHz to 100 kHz.

[0043] The magnetic composite material 10 of this embodiment can be suitably used, for example, as a material for forming components of a wireless power supply system. A wireless power supply system including a magnetic member containing the magnetic composite material 10 will be described below.

[0044] Fig. 5 is an explanatory diagram schematically illustrating the configuration of a wireless power feeding system 30 including a magnetic member containing a magnetic composite material 10. The wireless power feeding system 30 shown in Fig. 5 is a system that feeds power wirelessly by electromagnetic induction, and includes a wireless power feeding device 40 on the power receiving side and a wireless power feeding device 50 on the power transmitting side.

[0045] The wireless power transfer device 40 includes a magnetic member 41, a magnetic sheet 18, a circuit board 44, and a load 46. The magnetic member 41 includes a planar coil 42 serving as a secondary coil on the power receiving side and a covering 16 covering the planar coil 42. The covering 16 is formed of a magnetic composite material 10. The magnetic sheet 18 is a sheet that functions as a good magnetic material, and may be, for example, a metal sheet made of a soft magnetic metal or a ferrite sheet made of a soft magnetic ferrite. In the example shown in FIG. 5 , the planar coil 42 is covered by the covering 16 and is disposed on the back side of the magnetic sheet 18, with the portion hidden by the magnetic sheet 18 indicated by dashed lines. The circuit board 44 is electrically connected to the planar coil 42 and is provided to supply power generated by the planar coil 42 to the load 46. FIG. 5 shows, as an example, the wireless power transfer device 40 mounted on a vehicle (electric vehicle) 60. Vehicle 60 includes wireless power supply device 40 and a power storage device that stores power for driving vehicle 60. The power storage device corresponds to load 46 in FIG. 5 , and power generated in planar coil 42 is supplied to the power storage device via circuit board 44. Circuit board 44 includes a converter that converts the voltage when power is supplied from planar coil 42 to the power storage device into a voltage suitable for charging the power storage device. Note that, although load 46 in vehicle 60 is the power storage device, load 46 may also include a vehicle drive motor, allowing power to be directly supplied to the drive motor from wireless power supply device 40.

[0046] The wireless power supply device 50 includes a magnetic member 51, a magnetic sheet 18, a circuit board 54, and a load 56. The magnetic member 51 includes a planar coil 52 as a primary coil on the power transmission side, and a covering 16 that covers the planar coil 52. The covering 16 is formed of a magnetic composite material 10. In the example shown in FIG. 5 , the planar coil 52 is covered by the covering 16, and the portion hidden by the covering 16 is indicated by a dashed line. In the wireless power supply device 50, the magnetic member 51 is disposed on the magnetic sheet 18. The circuit board 54 is electrically connected to the planar coil 52 and is provided to supply AC power to the planar coil 52. For example, as shown in FIG. 5 , when the power receiving side wireless power supply device 40 is mounted on a vehicle 60, the wireless power supply device 50 may be installed at a specific location provided for power supply so as to be able to supply power to the vehicle 60 parked at the specific location. The circuit board 54 includes a converter that converts the voltage when power is supplied from the power supply device 56 to the planar coil 52 into a voltage suitable for power supply operation using the planar coil 52, and an inverter.

[0047] In magnetic member 41 and magnetic member 51, planar coil 42 or planar coil 52 can be integrated with covering portion 16 by, for example, adhering magnetic composite material 10 constituting covering portion 16 to the coil while magnetic composite material 10 is in an uncured state, and then curing magnetic composite material 10.

[0048] Fig. 6 is an explanatory diagram that schematically shows the arrangement of magnetic member 41 and magnetic member 51. Fig. 6 shows a cross section perpendicular to the surface direction of magnetic member 41 and magnetic member 51. As shown in the figure, magnetic member 41 and magnetic member 51 are arranged facing each other, and magnetic sheets 18 are arranged on the outside of magnetic member 41 and magnetic member 51, respectively.

[0049] FIG. 7 is a cross-sectional view illustrating the operation of wireless power supply using a wireless power supply system 30 including a wireless power supply device 40 on the power receiving side and a wireless power supply device 50 on the power transmitting side. FIG. 7 shows an enlarged view of a portion of a cross section perpendicular to the plane direction of the magnetic member 41 and the magnetic member 51, corresponding to FIG. 1(B). In FIG. 7, the state of magnetic flux during electromagnetic induction is indicated by a broken line as magnetic flux 32. Also, in FIG. 7, the direction of magnetic field lines is indicated by arrows. As shown in the figure, in the magnetic member 41, the magnetic composite material 10 is filled between adjacent wire rods of the planar coil 42. Similarly, in the magnetic member 51, the magnetic composite material 10 is filled between adjacent wire rods of the planar coil 52. Because the magnetic composite material 10 contains soft magnetic particles, when electromagnetic induction is performed using the primary coil (planar coil 52) and the secondary coil (planar coil 42) arranged opposite to each other, the spread of the magnetic field from the coil can be suppressed, and the mutual cancellation of magnetic fields generated between adjacent wire rods (proximity effect) can be suppressed. As a result, it is possible to reduce AC resistance and improve power transmission efficiency.

[0050] Since the real part μ′ of the complex relative permeability of the magnetic composite material 10 of this embodiment is 5 or more, by covering a coil with the magnetic composite material 10, the magnetic field can be confined around the coil without being eliminated.

[0051] Furthermore, when electromagnetic induction is performed using a primary coil and a secondary coil arranged opposite to each other, magnetic flux spreads to the outside of the primary coil and the secondary coil if coating 16 formed of magnetic composite material 10 is not provided. However, by providing coating 16 in which planar coil 52 and planar coil 42 are each coated with magnetic composite material 10 as shown in Fig. 7, magnetic flux can be converged and confined around planar coil 52 and planar coil 42, thereby ensuring high power supply efficiency.

[0052] As described above, the magnetic flux converging performance can be improved by reducing the value of the imaginary part μ" of the complex relative permeability of the magnetic composite material 10. For example, when a magnetic sheet made of a magnetic composite material comprising a soft magnetic material and an elastomer is used as a radio wave absorber, the value of the imaginary part μ" can be increased in the frequency band used to increase magnetic loss and release the radio wave energy as heat, thereby improving the performance as a radio wave absorber. Therefore, the properties of the magnetic composite material 10 of this embodiment, in which the value of the imaginary part μ" is reduced, can be said to be characteristics specific to magnetic materials that are suitable for converging magnetic flux, as described above.

[0053] Furthermore, because the magnetic composite material 10 including the soft magnetic body 14 has excellent magnetic shielding properties, it is possible to prevent the relatively high-frequency magnetic flux transmitted from the planar coil 52 in the wireless power supply device 40 from penetrating the covering 16 made of the magnetic composite material 10. Therefore, in the case where the wireless power supply device 40 includes, for example, a metal housing that houses the magnetic member 41, it is possible to prevent the magnetic flux transmitted from the planar coil 52 from reaching the housing. This prevents a decrease in power transmission efficiency and excessive heat generation due to eddy currents being generated in the metal housing by the magnetic flux that has reached the housing.

[0054] As described above, by configuring the wireless power supply system 30 using the magnetic composite material 10, the vibration resistance of the wireless power supply device 40 or the wireless power supply device 50 can be improved, and damage to the magnetic composite material 10 can be suppressed even when the wireless power supply device 40 or the wireless power supply device 50 is subjected to an impact. Here, the frequency of vibrations occurring when an automobile is traveling is generally considered to be approximately several Hz to 200 Hz. Therefore, by setting the loss factor tanδ of the magnetic composite material 10 to the above-described value as determined by dynamic viscoelasticity measurement at room temperature in a frequency range of 1 Hz to 110 Hz, when a magnetic component 41 having a coating 16 made of the magnetic composite material 10 is mounted on and used in a vehicle as described above, the vibration absorption performance of the magnetic composite material 10 can be ensured, and damage to the magnetic component 41 caused by vibration can be suppressed. Furthermore, by including the magnetic composite material 10 with excellent vibration resistance in the wireless power supply device 50 on the power transmission side, damage to the magnetic component 51 caused by vibration can be suppressed even when an impact is applied due to vibrations, for example, when a vehicle enters or exits the vehicle for power supply.

[0055] The magnetic composite material 10 of the above-described embodiment may be used for applications other than wireless power supply devices for electric vehicles. For example, it can be used in wireless power supply devices provided in aircraft, satellites, smartphones, tablet terminals, small home appliances, etc. When used in wireless power supply devices provided in equipment that is subjected to vibrations similar to electric vehicles, the magnetic composite material 10 can achieve the same effects due to its excellent vibration resistance. [Example]

[0056] FIG. 8 is an explanatory diagram showing the specific configurations (constituent materials and amounts added) of 12 types of magnetic composite materials, Samples S1 to S12. FIG. 9 is an explanatory diagram showing the measured values related to the performance of Samples S1 to S12. FIG. 10 is an explanatory diagram showing the evaluation results of the magnetic composite materials of Samples S1 to S12. The configuration and manufacturing method of each sample, as well as the results of performance evaluation, are described below. Each sample differs in the type of materials used, the mixing ratio of the materials, and the manufacturing method. Samples S3, S5, S7, and S9 to S11 are comparative examples that do not satisfy the conditions related to the magnetic composite material 10 described in the embodiment.

[0057] <Preparation of each sample> [Samples S1-S8, S12] Magnetic composite materials S1 to S8 and S12 were prepared using silicone resin with the molecular weight between crosslinks shown in Figure 8 and soft magnetic filler of the particle size and type shown in Figure 8, with the filler content set to the ratio shown in Figure 8. Figure 8 also shows the approximate aspect ratios of the soft magnetic fillers used in Samples S1 to S8, S12, and Sample S9 (described later). Specifically, Samples S1 to S8 and S12 were prepared by adding a predetermined amount of soft magnetic filler to silicone resin with a vinyl functional group and mixing the mixture using a mixer with stirring blades and a three-roll mill to obtain a paste. Only the paste of Sample S1 exhibited high viscosity, so toluene was added as a solvent. A silane coupling agent, a crosslinking agent, and a metal catalyst were added to these pastes and thoroughly mixed. The resulting pastes were formed into 2 mm-thick sheets using a doctor blade method and thermally cured at temperatures above 100°C to obtain sheets of magnetic composite material for each sample. The molecular weight of the raw material silicone resin having reactive functional groups such as vinyl groups, alkenyl groups, hydrosilyl groups, and alkoxyl groups is the molecular weight between crosslinking points after crosslinking by thermal curing.

[0058] [Sample S9] A soft magnetic filler (Mn-Zn ferrite) was added to the liquid epoxy resin at 50% by volume, and the mixture was mixed using a mixer with a stirring blade and a three-roll mill to obtain a paste. An epoxy curing agent was added to the paste and thoroughly mixed. The paste containing the curing agent was formed into a 2 mm thick sheet using the doctor blade method and cured at a temperature below 60°C to obtain a sheet made of the magnetic composite material of sample S9.

[0059] [Samples S10, S11] For samples S10 and S11, ferrite tiles were prepared and then attached to a PET (polyethylene terephthalate) film to create a magnetic composite sheet. Sample S10 used Ni-Zn ferrite tiles, while sample S11 used Mn-Zn ferrite tiles. Specifically, the raw materials, iron oxide, nickel oxide, zinc oxide, and manganese oxide, were mixed to the desired composition ratio and wet-mixed in a ball mill. The mixed powder was dried and then calcined at temperatures above 600°C. The resulting powder was then pulverized in a wet ball mill, and a binder was added and mixed to obtain a slurry. The resulting slurry was spray-dried to form granules, which were then press-molded into 2 mm thick, 10 mm square pieces. The resulting molded bodies were degreased and then fired at temperatures above 1000°C while adjusting the oxygen partial pressure. A large number of ferrite tiles were prepared for each sample. These ferrite tiles were arranged two-dimensionally at equal intervals, and after applying adhesive, they were attached to PET films in a vacuum. PET films were attached to both sides of the tiles to create sheets for samples S10 and S11.

[0060] When carrying out the measurements described below, a test piece of a size suitable for the measurement was prepared for each sample by cutting, molding, or press molding, depending on the sample.

[0061] <Derivation of complex relative permeability> Complex permeability was measured using a microstrip line and a vector network analyzer in the range of 1 kHz to 1 MHz, and an E4991B impedance analyzer (Keysight Technologies) in the range of 1 MHz to 1 GHz. The samples were either plate-shaped or ring-shaped. In Figure 9, the real part μ' of the complex relative permeability is shown as the minimum value of the real part in the frequency range of 50 kHz to 100 kHz. The imaginary part μ" of the complex relative permeability is shown as the maximum value of the imaginary part in the frequency range of 50 kHz to 100 kHz.

[0062] <Measurement of elongation rate> The elongation was measured at room temperature using a tensile tester (Shimadzu Autograph (AG-IS)). Specifically, each sample was cut into a rectangular test piece measuring 1 cm wide and 7 cm long. The test piece was held in place with a jig at positions 2 cm from both ends, and a tensile test was performed on the middle section, 3 cm long. Each test piece was pulled until it broke, and the elongation was calculated by subtracting the original sample length (3 cm for the above sample) from the sample length at break and then dividing by the original sample length. For samples S10 and S11, the ferrite tile and PET film were evaluated separately, and the smaller value was selected.

[0063] <Rubber hardness measurement> The rubber hardness was measured using a type A durometer specified in JIS K 6235-3:2012.

[0064] <Derivation of storage modulus and loss factor tanδ> Dynamic viscoelasticity measurements were used to measure the storage modulus and loss modulus at frequencies from 0.1 Hz to 110 Hz, and the loss factor tanδ was calculated from the obtained values. For samples S10 and S11, the above measurements were performed on the PET film, which is responsible for flexibility, of the ferrite tile and PET film. Samples were cut into sizes of 50 mm length x 4 mm width, and measurements were performed under a tensile load of 1 gf and an excitation amplitude of 16 μm. A known dynamic viscoelasticity measuring device can be used for the measurement, such as the Rheovibron DDV-01GP manufactured by A&D Co., Ltd.

[0065] Fig. 11 is an explanatory diagram showing the values of the loss factor tan δ of samples S6 to S8, S10, and S12 at frequencies of 0.1 Hz to 110 Hz, and Fig. 12 is an explanatory diagram showing the values of the storage modulus of samples S6 to S8, S10, and S12 at frequencies of 0.1 Hz to 110 Hz. In Fig. 11, the loss factor tan δ of each sample is shown as the loss factor tan δ measured at room temperature in the frequency range of 1 Hz to 110 Hz, while Fig. 9 shows the minimum value in the frequency range of 0.1 Hz to 110 Hz. In Fig. 12, the storage modulus of each sample is shown as the maximum value of the storage modulus measured at room temperature in the frequency range of 1 Hz to 110 Hz.

[0066] <Calculation of shear adhesive strain> FIG. 13 is an explanatory diagram schematically illustrating a method for calculating shear adhesive strain. A known tensile tester (e.g., Shimadzu Autograph (AG-IS)) was used to measure the shear adhesive strain (strain amount) of the magnetic composite material in a tensile test. Specifically, a test piece for measurement was prepared by attaching a 0.4 mm thick sheet of the sample prepared as described above to the 12.5 mm wide x 12.5 mm long end of two aluminum plates 201 and 202, each measuring 12.5 mm wide x 100 mm long x 1 mm thick. The two aluminum plates were bonded together in a direction that allowed them to be pulled in opposite directions, and then heated at 100°C for 10 hours. This resulted in the formation of a magnetic composite material SA, the shear adhesive strain of which was to be calculated, as shown in columns A and B of FIG. 13 . The total thickness t of the magnetic composite test pieces attached to the two aluminum plates 201 and 202 was 0.8 mm. Next, the two aluminum plates 201 and 202 were moved relative to each other so that a shear force was applied to the magnetic composite material SA. For example, using a tensile tester, one of the aluminum plates 201 was moved in one direction parallel to the bonding surface (e.g., upward in column C of Figure 13) at a tensile speed of 2 mm / min while measuring the load and movement distance. The shear adhesive stress was calculated by dividing the load by the bonding area (12.5 mm × 12.5 mm) of the magnetic composite material before movement. This relative movement of the two aluminum plates 201 and 202 was continued until the magnetic composite material SA broke, and the distance ΔL at which the shear adhesive stress reached its maximum was measured. Finally, the shear adhesive strain (%) of the magnetic composite material SA was calculated by dividing the distance ΔL by the total thickness t of the magnetic composite material SA before movement, as shown in the following equation (1): Shear bond strain (%) = (ΔL / t) × 100 (1)

[0067] The shear adhesive strain of a magnetic composite material bonded to an adherend can be measured using the following method. First, the magnetic composite material is cut out together with the adherend by laser cutting or other methods. The size and shape of the cut test piece need only be such that it can be held in the jig of a tensile tester and that a load can be applied in the shear direction by pulling or compressing the two adherends bonded by the magnetic composite material in opposite directions as shown in Figure 13. The thickness of the magnetic composite material is not particularly limited, so the cut magnetic composite material with adherend can be used directly for measurement. Before conducting the test, the adhesive area and thickness of the magnetic composite material on the cut test piece are measured. The test is then performed in the same manner as described above, and the shear adhesive strain (%) is calculated by dividing the distance ΔL at which the shear adhesive stress reaches its maximum by the total thickness t of the magnetic composite material.

[0068] <Evaluation method> As shown in Figure 10, each item was evaluated by comparing it with the standard value. For "loss factor tan δ," if the value of the loss factor tan δ of each sample was 0.05 or more, it was marked as "○," and if it was less than 0.05, it was marked as "×." For "storage modulus," if the storage modulus of each sample was 200 MPa or less, it was marked as "○," and if it was more than 200 MPa, it was marked as "×." For "elongation," if the elongation of each sample was 30% or more, it was marked as "○," and if it was less than 30%, it was marked as "×." For "rubber hardness," if the rubber hardness of each sample was 80 or less, it was marked as "○," and if it was more than 80, it was marked as "×." For "μ"," if the imaginary part μ" of the complex relative permeability of each sample in the frequency range of 50 kHz to 100 kHz was 2.0 or less, it was marked as "○," and if it was more than 2.0, it was marked as "×." For "μ" peak, if the peak of the imaginary part μ" of the complex relative magnetic permeability of each sample was 150 kHz or higher, it was marked as "○", and if it was less than 150 kHz, it was marked as "×". For "μ'", if the real part μ' of the complex relative magnetic permeability in the frequency range of 50 kHz to 100 kHz of each sample was 5 or higher, it was marked as "○", and if it was less than 5, it was marked as "×". For "shear bond strain", if the shear bond strain value of each sample was 20 or higher, it was marked as "○", and if it was less than 29, it was marked as "×".

[0069] Figure 10 also shows the results of the overall evaluation. The "overall evaluation" was marked with "X" when the main evaluation item related to vibration resistance, which is the basic performance of the magnetic composite material of the present disclosure, i.e., the "loss factor tan δ," was marked with "X." In addition, when the overall evaluation was other than "X," and there were no "X" evaluation items among the remaining evaluation items, the evaluation was marked with "◎," when there was one "X" evaluation item, the evaluation was marked with "○," and when there were two or more "X" evaluation items, the evaluation was marked with "△."

[0070] <Evaluation results> As shown in Figures 8 to 10, in order to suppress the AC resistance of the coil while ensuring the vibration resistance of the magnetic sheet, it was confirmed that it is important to incorporate a soft magnetic material into the resin material and to use an elastomer such as silicone rubber as the resin material (comparison of samples S1 to S8, S12 with samples S9 to S11).

[0071] Furthermore, it was confirmed that the real part μ' of the complex relative magnetic permeability could be increased by adding 20% or more of filler to the Fe-Si-Al flat powder, thereby improving magnetic properties (Samples S1 and S2). In the case of spherical Fe-Si-Al, adding 45% or more of filler could increase the real part μ' of the complex relative magnetic permeability, thereby improving magnetic properties (Comparison between Samples S3 and S4). In the case of Ni-Zn ferrite, Mn-Zn ferrite, and spherical Fe-Si-Cr-B, adding 45% or more of filler could increase the real part μ' of the complex relative magnetic permeability, thereby improving magnetic properties (Comparison between Samples S6, S8, S9, and S12 and S5 and S7). It is presumed that a flat shape is preferable to a spherical shape in order to increase the real part μ' of the complex relative magnetic permeability (Comparison between Samples S1 and S3).

[0072] It was confirmed that by changing the shape of the powder particles of the soft magnetic material from flat to closer to spherical, it is possible to reduce the storage modulus and rubber hardness, thereby improving vibration resistance, increase the elongation rate and shear adhesive strain, and shift the peak of the imaginary part μ" of the complex relative permeability to the higher frequency side (comparison of samples S3 to S8, S12 with samples S1 and S2).

[0073] It was also confirmed that the elongation and shear adhesive strain of the magnetic sheet could be further increased by increasing the molecular weight between crosslinking points of the silicone elastomer to 40,000 or more (comparison of samples S3 to S6, S12: molecular weight 50,000 or more with samples S1, S2, S7, S8: molecular weight 30,000).

[0074] Furthermore, by using a magnetic composite material with a shear adhesive strain of 20% or more, it was confirmed that the storage modulus of the magnetic sheet decreased, the elongation increased, and the rubber hardness decreased (comparison of samples S3 to S8, S12 with samples S1, S2, S9 to S11). Furthermore, adhesion to metals such as aluminum was confirmed, and the vibration resistance of magnetic components equipped with coils could be improved. It was also confirmed that it is important to use an elastomer such as silicone rubber as the resin material (comparison of samples S3 to S8, S12 with samples S9 to S11).

[0075] The present disclosure is not limited to the above-described embodiments, and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0076] The present disclosure can also be realized as the following application examples. [Application example 1] 1. A magnetic composite material comprising: A resin material and a soft magnetic material contained in the resin material, The loss factor tanδ measured by dynamic viscoelasticity measurement at room temperature in the frequency range of 1 Hz to 110 Hz is 0.05 or more, The real part μ' of the complex relative permeability in the frequency range of 50 kHz to 100 kHz is 5 or more. Magnetic composite material. [Application example 2] The magnetic composite material according to Application Example 1, The storage modulus measured by dynamic viscoelasticity measurement at room temperature in the frequency range of 1 Hz to 110 Hz is 200 MPa or less. Magnetic composite material. [Application example 3] The magnetic composite material according to Application Example 1 or Application Example 2, Characterized by an elongation rate of 30% or more at room temperature Magnetic composite material. [Application example 4] The magnetic composite material according to any one of Application Examples 1 to 3, The rubber hardness measured with a type A durometer specified in JIS K 6235-3:2012 is 80 or less. Magnetic composite material. [Application example 5] The magnetic composite material according to any one of Application Examples 1 to 4, The soft magnetic material contains at least one of a metal and a ferrite. Magnetic composite material. [Application Example 6] The magnetic composite material according to any one of Application Examples 1 to 5, The resin material is silicone rubber. Magnetic composite material. [Application Example 7] The magnetic composite material according to any one of Application Examples 1 to 6, The imaginary part μ" of the complex relative permeability has a peak of 150 kHz or higher. Magnetic composite material. [Application Example 8] The magnetic composite material according to any one of Application Examples 1 to 7, The imaginary part μ" of the complex relative permeability in the frequency range of 50 kHz to 100 kHz is 2.0 or less. Magnetic composite material. [Application Example 9] The magnetic composite material according to any one of Application Examples 1 to 8, Characterized by a shear adhesive strain of 20% or more for the aluminum plate Magnetic composite material. [Application Example 10] A magnetic member, a planar coil in which wire is wound in a spiral shape; a covering portion made of the magnetic composite material according to any one of Application Examples 1 to 9, the covering portion covering the planar coil; Equipped with Magnetic components. [Application Example 11] A wireless power supply device, a planar coil in which wire is wound in a spiral shape; a covering portion made of the magnetic composite material according to any one of Application Examples 1 to 9, the covering portion covering the planar coil; a circuit board electrically connected to the planar coil for supplying AC power to the planar coil or for supplying power generated by the planar coil to a load; Equipped with Wireless power supply device. [Explanation of symbols]

[0077] 10,10a,10b,SA...Magnetic composite material 12...Resin material 14,14a,14b...Soft magnetic material 16...Covering part 18...Magnetic sheet 20…object 30...Wireless power supply system 32...Magnetic flux 40,50...Wireless power supply devices 41, 51...Magnetic members 42, 52... Planar coil 44, 54...Circuit board 46...Load 56...Power supply device 60...Vehicle 201...Aluminum plate

Claims

1. 1. A magnetic composite material comprising: A resin material and a soft magnetic material contained in the resin material, The loss factor tanδ measured by dynamic viscoelasticity measurement at room temperature in a frequency range of 1 Hz to 110 Hz is 0.05 or more, The real part μ' of the complex relative permeability in the frequency range of 50 kHz to 100 kHz is 5 or more. Magnetic composite material.

2. 2. The magnetic composite material of claim 1, The storage modulus measured by dynamic viscoelasticity measurement at room temperature in the frequency range of 1 Hz to 110 Hz is 200 MPa or less. Magnetic composite material.

3. 2. The magnetic composite material of claim 1, The elongation at room temperature is 30% or more. Magnetic composite material.

4. 2. The magnetic composite material of claim 1, The rubber hardness measured by a type A durometer specified in JIS K 6235-3:2012 is 80 or less. Magnetic composite material.

5. 2. The magnetic composite material of claim 1, The soft magnetic material contains at least one of a metal and a ferrite. Magnetic composite material.

6. 2. The magnetic composite material of claim 1, The resin material is silicone rubber. Magnetic composite material.

7. 2. The magnetic composite material of claim 1, The peak of the imaginary part μ″ of the complex relative permeability is 150 kHz or higher. Magnetic composite material.

8. 2. The magnetic composite material of claim 1, The imaginary part μ″ of the complex relative permeability in the frequency range of 50 kHz to 100 kHz is 2.0 or less. Magnetic composite material.

9. 2. The magnetic composite material of claim 1, The shear adhesive strain to the aluminum plate is 20% or more. Magnetic composite material.

10. A magnetic member, a planar coil in which wire is wound in a spiral shape; a covering portion that covers the planar coil and that is made of the magnetic composite material according to any one of claims 1 to 9; Equipped with Magnetic components.

11. A wireless power supply device, a planar coil in which wire is wound in a spiral shape; a covering portion that covers the planar coil and that is made of the magnetic composite material according to any one of claims 1 to 9; a circuit board electrically connected to the planar coil for supplying AC power to the planar coil or for supplying power generated by the planar coil to a load; Equipped with Wireless power supply device.

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