WO2013077285A1 - Composite magnet, antenna provided therewith, and non-contact ic card - Google Patents

Composite magnet, antenna provided therewith, and non-contact ic card Download PDF

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Publication number
WO2013077285A1
WO2013077285A1 PCT/JP2012/079932 JP2012079932W WO2013077285A1 WO 2013077285 A1 WO2013077285 A1 WO 2013077285A1 JP 2012079932 W JP2012079932 W JP 2012079932W WO 2013077285 A1 WO2013077285 A1 WO 2013077285A1
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Prior art keywords
magnetic
magnetic powder
less
mhz
resin
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PCT/JP2012/079932
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French (fr)
Japanese (ja)
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石塚　雅之
剛 川瀬
康徳 国光
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住友大阪セメント株式会社
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Publication of WO2013077285A1 publication Critical patent/WO2013077285A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/20—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/20—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder
    • H01F1/22—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together
    • H01F1/24—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together the particles being insulated
    • H01F1/26—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together the particles being insulated by macromolecular organic substances
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
    • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
    • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
    • B42D25/30—Identification or security features, e.g. for preventing forgery
    • B42D25/36—Identification or security features, e.g. for preventing forgery comprising special materials
    • B42D25/369—Magnetised or magnetisable materials

Definitions

  • the present invention relates to a composite magnetic body, an antenna including the same, and a non-contact IC card, and more particularly, loading to an antenna using an electromagnetic wave in a frequency band from 10 MHz to 70 MHz, or an electronic using an electromagnetic wave in this frequency band.
  • the present invention relates to a composite magnetic body suitable for use as a magnetic material constituting a component, an antenna including the composite magnetic body, and a non-contact IC card including the composite magnetic body.
  • RFID Radio Frequency Identification
  • This non-contact IC card is also called an IC tag, and is widely used as a transportation card or electronic money.
  • an electromagnetic induction method based on magnetic flux coupling between a coil built in the non-contact IC card and a coil built in the reader or reader / writer is often used.
  • the frequency used there is often 13.56 MHz.
  • a magnetic shield sheet having a magnetic shield layer having a large real part ⁇ r ′ of complex permeability (hereinafter sometimes abbreviated as ⁇ r ′) between the non-contact IC card and the metal member.
  • ⁇ r ′ complex permeability
  • the complex permeability imaginary part ⁇ r ′′ (hereinafter sometimes abbreviated as ⁇ r ′′) and the complex dielectric constant real part ⁇ r ′ (hereinafter abbreviated as ⁇ r ′) may be sometimes used.
  • the imaginary part ⁇ r ′′ (hereinafter sometimes abbreviated as ⁇ r ′′) of the complex dielectric constant is large, there is a problem that the signal energy of the magnetic field lines is attenuated.
  • ⁇ r ′ was 100 or more and ⁇ r ′′ was 60 or more.
  • ⁇ r ′ is large and tan ⁇ so that the communication distance between the non-contact IC card and the reader or the reader / writer can be increased.
  • the present invention has been made in view of the above circumstances, and can be applied to a frequency band from 10 MHz to 70 MHz. Moreover, the real part ⁇ r ′ of the complex permeability in this frequency band is large, and the complex permeability. It is an object of the present invention to provide a composite magnetic body having a low loss tangent tan ⁇ , a real part ⁇ r ′ of a complex dielectric constant and a loss tangent tan ⁇ of a complex dielectric constant, an antenna including the same, and a contactless IC card.
  • the inventors of the present invention have made extensive studies to solve the above problems. As a result, the shape of the magnetic powder in the composite magnetic body in which the magnetic powder is dispersed in the insulating material is flattened, and the real part ⁇ r ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz of the composite magnetic body.
  • the loss tangent tan ⁇ of the complex permeability is 0.02 or less
  • the real part ⁇ r ′ of the complex permittivity is 50 or less
  • the loss tangent tan ⁇ of the complex permittivity is 0.2 or less, or 10 MHz
  • the real part ⁇ r ′ of the complex permeability in the frequency band from 1 to 20 MHz is greater than 1
  • the loss tangent tan ⁇ of the complex permeability is 0.01 or less
  • the real part ⁇ r ′ of the complex permittivity is 50 or less
  • the complex permittivity If the loss tangent tan ⁇ is 0.2 or less, this composite magnetic body can be applied to a non-contact IC card.
  • the non-contact IC card and the reader or reader / writer It found that it is possible to take the communication distance to the long, and have completed the present invention.
  • the composite magnetic body of the present invention is a composite magnetic body in which magnetic powder is dispersed in an insulating material, and the magnetic powder is flat and has a complex permeability in a frequency band from 10 MHz to 70 MHz.
  • the part ⁇ r ′ is larger than 1, the loss tangent tan ⁇ of the complex permeability is 0.02 or less, the real part ⁇ r ′ of the complex permittivity is 50 or less, and the loss tangent tan ⁇ of the complex permittivity is 0.2 or less.
  • Another composite magnetic body of the present invention is a composite magnetic body in which magnetic powder is dispersed in an insulating material, and the magnetic powder is flat and has a complex permeability in a frequency band from 10 MHz to 20 MHz.
  • the part ⁇ r ′ is larger than 1, the loss tangent tan ⁇ of the complex permeability is 0.01 or less, the real part ⁇ r ′ of the complex permittivity is 50 or less, and the loss tangent tan ⁇ of the complex permittivity is 0.2 or less.
  • the magnetic powder has an average thickness of 0.01 ⁇ m to 10 ⁇ m, an average major axis of 0.05 ⁇ m to 20 ⁇ m, and an average aspect ratio (major axis / thickness) of 5 or more. Is preferred.
  • the magnetic powder includes aluminum (Al), chromium (Cr), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), niobium (Nb), molybdenum (Mo), and indium (In).
  • An iron-nickel alloy containing one or more metal elements selected from the group of tin (Sn) is preferable.
  • the magnetic powder is preferably formed by deforming and fusing the spherical magnetic particles by applying mechanical stress to the spherical magnetic particles having an average particle diameter of 3 ⁇ m or less.
  • the antenna of the present invention is loaded with the composite magnetic material of the present invention, and is characterized by transmitting, receiving or transmitting / receiving radio waves in a frequency band from 10 MHz to 70 MHz.
  • the non-contact IC card of the present invention comprises the composite magnetic body of the present invention.
  • the magnetic powder is flattened, and the real part ⁇ r ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is larger than 1, and the loss tangent tan ⁇ of the complex permeability is Since 0.02 or less, the real part ⁇ r ′ of the complex dielectric constant is 50 or less, and the loss tangent tan ⁇ of the complex dielectric constant is 0.2 or less, it is possible to suppress the attenuation of the signal energy of the magnetic field lines in this frequency band.
  • the antenna efficiency in the frequency band from 10 MHz to 70 MHz can be increased.
  • the non-contact IC card of the present invention since the composite magnetic body of the present invention is provided, the attenuation of the signal energy of the magnetic field lines in the frequency band from 10 MHz to 70 MHz can be suppressed. Therefore, the communication distance between the non-contact IC card and the reader or reader / writer can be increased.
  • the composite magnetic body of this embodiment is a composite magnetic body in which magnetic powder is dispersed in an insulating material.
  • This magnetic powder is flat and has the following magnetic characteristics (1).
  • (1) The real part ⁇ r ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is greater than 1, the loss tangent tan ⁇ of the complex permeability is 0.02 or less, the real part ⁇ r ′ of the complex permittivity is 50 or less, The loss tangent tan ⁇ of the complex dielectric constant is 0.2 or less.
  • the composite magnetic body of the present embodiment may have the following magnetic property (2).
  • the real part ⁇ r ′ of the complex permeability in the frequency band from 10 MHz to 20 MHz is larger than 1, the loss tangent tan ⁇ of the complex permeability is 0.01 or less, the real part ⁇ r ′ of the complex permittivity is 50 or less, The loss tangent tan ⁇ of the complex dielectric constant is 0.2 or less.
  • the real part ⁇ r ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is preferably 4 or more, and more preferably 6 or more.
  • the loss tangent tan ⁇ of the complex permeability in the frequency band from 10 MHz to 70 MHz is preferably 0.02 or less, and more preferably 0.015 or less.
  • the real part ⁇ r ′ of the complex dielectric constant in the frequency band from 10 MHz to 70 MHz is preferably 30 or less.
  • the loss tangent tan ⁇ of the complex dielectric constant in the frequency band from 10 MHz to 70 MHz is preferably 0.1 or less, and more preferably 0.05 or less.
  • the real part ⁇ r ′ of the complex permeability, the loss tangent tan ⁇ of the complex permeability, the real part ⁇ r ′ of the complex permittivity, and the loss tangent tan ⁇ of the complex permittivity are limited to the above ranges. This is because the composite magnetic body can suppress the signal energy attenuation of the magnetic field lines while maintaining the performance of the magnetic shield.
  • the shape and thickness of the composite magnetic body are not particularly limited and may be appropriately changed depending on the application.
  • the composite magnetic body The thickness is preferably about 10 ⁇ m to 1 mm.
  • the above ⁇ r ′, ⁇ r ′, tan ⁇ and tan ⁇ are values measured by a material analyzer, but any measuring device can be used as long as each of the above values can be measured with the same accuracy as the material analyzer. Not limited to material analyzers.
  • Magnetic powder The material constituting the magnetic powder of the present embodiment is not particularly limited as long as it is a material having magnetism.
  • a ferromagnetic metal such as terbium (Tb) or dysprosium (Dy)
  • a metal composed of any one of paramagnetic metals such as molybdenum (Mo)
  • Mo molybdenum
  • alloy containing at least one of these metals it can.
  • These metals or alloys may contain diamagnetic metals such as copper (Cu), zinc (Zn), and bismuth (Bi).
  • Examples of these alloys include two-element alloys and three-element alloys.
  • Examples of the two-element alloys include Fe-Ni alloys such as Permalloy (registered trademark) that exhibit a soft magnetism with a coercive force of 70 Oersted (Oe) or less, Fe-Si alloys, Fe-Co alloys, Fe-Cr alloys, and the like. It is done.
  • Examples of the ternary alloy include Fe—Ni—Mo alloys such as Supermalloy (registered trademark), Fe—Si—Al alloys such as Sendust (registered trademark), and Fe—Cr—Si alloys.
  • an alloy of Ni 78 mass% -Fe 22 mass% is a flat magnetic powder, for example, a flat magnetic powder having an average thickness of 10 ⁇ m or less and an average major axis of 20 ⁇ m or less. It is preferable because a body can be easily obtained and a magnetic powder with high magnetic permeability and low magnetic loss can be obtained.
  • a metal element that is not included in the alloy and has similar properties to the alloy a metal that is close to the metal in the alloy in the periodic table
  • aluminum Al
  • Cr chromium
  • Mn manganese
  • Co cobalt
  • Cu copper
  • Zn zinc
  • Nb niobium
  • Mo molybdenum
  • In indium
  • Sn tin
  • the content of the metal element is preferably 0.1% by mass or more and 90% by mass or less, preferably 1% by mass with respect to the total mass of the metal element and the alloy. It is more preferably 12% by mass or less, and further preferably 1% by mass or more and 5% by mass or less.
  • the reason why the metal element content is limited to the above range is that, if the metal element content is less than 0.1% by mass, sufficient plasticity for flattening the spherical magnetic particles described later is used.
  • the content rate exceeds 90% by mass, the magnetic moment of the metal element itself is small, so that the saturation magnetization of the entire flat magnetic powder becomes small, and as a result. This is because the obtained ⁇ r ′ is also small.
  • a group of soft metals such as aluminum (Al), zinc (Zn), indium (In), and tin (Sn) in that the aspect ratio is high and a high ⁇ r ′ composite magnetic body is easily obtained as a result. It is preferable to use an iron-nickel alloy containing one or more metal elements selected from 1 to 12% by mass, preferably 1 to 5% by mass.
  • the nickel-iron-zinc (Ni—Fe—Zn) alloy has a large aspect ratio because the addition of Zn to the Fe—Ni alloy increases the workability of spherical magnetic particles described later.
  • a flat magnetic powder is preferred because it is easy to obtain.
  • the composition ratio of the alloy for example, an alloy of Ni 75% by mass—Fe 20% by mass—Zn 5% by mass, Ni 76% by mass—Fe 20% by mass—Zn 4% by mass, and the like can be preferably used.
  • This magnetic powder is preferably insulative.
  • the insulating magnetic powder it is possible to suppress the formation of a conductive path due to the contact between the magnetic powders in the composite magnetic body. As a result, the dielectric loss of the composite magnetic body is reduced. Can be reduced.
  • this insulating magnetic powder it is sufficient that at least the surface of the particles has an insulating property.
  • the method for making the magnetic powder insulative is not particularly limited, and examples thereof include a method of forming an insulating oxide film of about 5 nm on the surface of the magnetic powder.
  • an oxide film is naturally formed on the surface of the magnetic powder, but the oxide film formed naturally has insufficient insulation, It is difficult to reduce dielectric loss. Therefore, in order to reduce the dielectric loss of the composite magnetic material, the surface of the magnetic powder is insulated by about 5 nm by heat treatment at a temperature of 50 ° C. or more and 200 ° C. or less for about 1 hour to several hours. It is preferable to form an oxide film.
  • an insulating film having a composition different from that of the magnetic powder may be formed on the surface of the magnetic powder.
  • a composition include inorganic substances such as silicon oxide and phosphate, or organic substances such as resins and surfactants.
  • These insulating films may be formed on the surface of a magnetic powder having an oxide film (including an oxide film formed by natural oxidation or heat oxidation), or may be formed on the surface of a magnetic powder having no oxide film. Good.
  • the average thickness of the magnetic powder is preferably 0.01 ⁇ m or more and 10 ⁇ m or less, more preferably 0.1 ⁇ m or more and 1 ⁇ m or less.
  • the average major axis of the magnetic powder is preferably 0.05 ⁇ m or more and 20 ⁇ m or less, more preferably 0.2 ⁇ m or more and 10 ⁇ m or less.
  • the average thickness and average major axis of the magnetic powder are determined by measuring the thickness and major axis of each of the plurality of magnetic powders, for example, the thickness and major axis of each of the 100 or more magnetic powders, preferably 500 magnetic powders. The average value of each of the thickness and the major axis can be calculated.
  • the size of the magnetic powder is larger than the above range, when the composite magnetic body using the magnetic powder is disposed between the non-contact IC card and the metal member, the non-contact IC card and the metal member Since the magnetic powder itself is also a metal at the same time, an eddy current flows through this magnetic powder, and part of the signal energy of this magnetic field line changes to thermal energy, and the magnetic signal This is not preferable because there is a case where the attenuation of the above occurs. Further, if the average thickness is less than 0.01 ⁇ m, it will be difficult to manufacture as will be described later, and it will be difficult to handle, and if the average thickness exceeds 10 ⁇ m, it is not preferable. And tan ⁇ and tan ⁇ increase, which is not preferable.
  • the average major axis of the magnetic powder is less than 0.05 ⁇ m, it is difficult to manufacture the magnetic powder itself, and it is difficult to handle the composite magnetic body. As a result, the orientation is good and the complex permeability is low. This is not preferable because it is difficult to obtain a composite magnetic body having a high real part ⁇ r ′.
  • the average major axis of the magnetic powder exceeds 20 ⁇ m, the dispersion of the particles in the insulating material tends to become unstable, and the gap between the magnetic powders becomes too small. As a result, it becomes difficult for the insulating material to enter the gap, and as a result, pores are easily generated, and the desired ⁇ r ′ may not be obtained.
  • the average aspect ratio (length / thickness) of the magnetic powder is preferably 5 or more, more preferably 7 or more.
  • the reason why the shape of the magnetic powder is preferably a flat shape having an average aspect ratio (length / thickness) of 5 or more is as follows.
  • the magnitude of the demagnetizing field in the magnetic powder depends on the shape of the powder. For example, when the magnetic powder is spherical, since the demagnetizing field is isotropic, the magnetic permeability obtained is isotropic, and it is difficult to obtain excellent magnetic properties in the high frequency region.
  • the demagnetizing field in the direction parallel to the flat surface is much smaller than the flat demagnetizing field in the vertical direction, and thus the obtained ⁇ r ′ is large. Therefore, it is preferable.
  • the average aspect ratio when the average aspect ratio increases, the mechanical strength of the magnetic powder itself may be reduced. Therefore, in order to ensure the desired mechanical strength of the magnetic powder, the average aspect ratio is preferably 15 or less, and practically about 20 is the upper limit. Furthermore, when the average aspect ratio exceeds 20, the shape of the magnetic powder is too flat, the space between the magnetic bodies becomes narrow, and a space in which the insulating material does not easily enter is easily formed between the magnetic bodies. Bubbles are likely to be generated in the composite magnetic material, and the presence of the bubbles lowers ⁇ r ′, which is not preferable. Therefore, the average aspect ratio is preferably 5 or more and 20 or less, and more preferably 7 or more and 15 or less.
  • the average aspect ratio (major axis / thickness) of this magnetic powder is also the same as the above average thickness and average major axis, and the thickness and major axis of each of the plurality of magnetic powders, for example, 100 or more magnetic powders, preferably 500 It can be obtained by measuring the thickness and major axis of each of the magnetic powders and calculating the average value of the thickness and major axis.
  • the magnetic powder of the present embodiment is obtained by applying mechanical stress to spherical magnetic particles having an average particle diameter of 10 nm or more and 3 ⁇ m or less so that the spherical magnetic particles are brought into contact with each other and deformed and fused.
  • spherical magnetic particles having an average particle diameter of 10 nm or more and 3 ⁇ m or less have an average thickness of 0.01 ⁇ m or more and 10 ⁇ m or less, an average major axis of 0.05 ⁇ m or more and 20 ⁇ m or less, an average aspect ratio (long (Thickness / thickness) is 5 or more flat magnetic powder.
  • the average particle diameter of the spherical particles is set to 3 ⁇ m or less, the surface of the spherical particles becomes highly active when the average particle diameter is set to 3 ⁇ m or less, and the affinity between the particles is also increased. This is because deformation and fusion between particles are promoted, and flat magnetic powder is easily formed. More preferably, the average particle diameter of the spherical particles is 100 nm or more and 0.5 ⁇ m or less.
  • the mechanical strength is high, the hygroscopic property is low, and the shape workability is excellent.
  • thermosetting resin an epoxy resin excellent in mechanical strength and shape processability is preferable
  • thermoplastic resin a polystyrene resin, a polyphenylene resin, and an ABS resin are preferable. These resins may be used alone or in combination of two or more.
  • thermoplastic elastomer may be added to the above insulating material.
  • a thermoplastic elastomer By adding a thermoplastic elastomer, the mechanical strength and shape processability of the composite magnetic material can be improved. Therefore, the composite magnetic body to which the thermoplastic elastomer is added is excellent in toughness, flexibility and deformability.
  • thermoplastic elastomer one or more selected from the group of styrene elastomers, olefin elastomers, vinyl chloride elastomers, urethane elastomers, ester elastomers and amide elastomers can be used.
  • the amount of thermoplastic elastomer added may be adjusted as appropriate in consideration of the heat resistance required for the application of the composite magnetic material.
  • a slurry and a dispersion medium obtained by dispersing spherical magnetic particles having an average particle diameter of 3 ⁇ m or less in a solution containing a surfactant are placed in a sealable container.
  • the slurry is filled so that the total volume of the slurry and the dispersion medium is the same as the volume in the container, and the slurry is stirred together with the dispersion medium while applying mechanical stress (mechanical shear energy) in a sealed state.
  • spherical magnetic particles having an average particle diameter of 10 nm or more and 3 ⁇ m or less are dispersed in a solution containing a surfactant to obtain a slurry.
  • the composition of the magnetic particles is exactly the same as the composition of the above magnetic powder.
  • the method for producing the spherical magnetic particles is not particularly limited, and those synthesized by a known method such as a liquid phase reduction method or an atomization method can be used.
  • spherical particles having an average particle size of 3 ⁇ m or less are synthesized. In view of this, it is preferable to use a liquid phase reduction method.
  • a surfactant containing an element such as nitrogen, phosphorus or sulfur that is compatible with the surface of the magnetic particles is preferable, and examples thereof include a nitrogen-containing block copolymer, a phosphate, and polyvinylpyrrolidone.
  • an organic solvent is preferable because it is necessary to prevent oxidation of the metal element contained in the magnetic particles, and in particular, nonpolar organic materials such as xylene, toluene, cyclopentanone, and cyclohexanone. A solvent is preferred.
  • the slurry and the dispersion medium are filled in a sealable container so that the total volume of the slurry and the dispersion medium is the same as the volume in the container, and the slurry is stirred together with the dispersion medium in a sealed state. Then, the spherical magnetic particles are deformed and fused to form a flat magnetic powder.
  • the dispersion medium must be harder than spherical magnetic particles, for example, metal spheres such as aluminum, steel (steel), stainless steel, and lead, and metal oxides such as alumina, zirconia, silicon dioxide, and titania.
  • Spherical sintered body made of an inorganic oxide such as silicon nitride
  • spherical sintered body made of inorganic nitride such as silicon nitride
  • spherical sintered body made of inorganic carbide such as silicon carbide, soda glass, lead glass, high specific gravity glass, etc.
  • zirconia, steel (steel), stainless steel and the like having a specific gravity of 6 or more are preferable from the viewpoint of efficiency.
  • the mechanical stress is applied to the spherical magnetic particles because the spherical magnetic particles are sandwiched between the dispersion medium and the dispersion medium or between the dispersion medium and the inner wall of the closed container when the dispersion medium collides. It is done by the shock given. Therefore, as the number of collisions between the dispersion media or between the dispersion media and the container wall increases, the deformation and fusion properties between the spherical magnetic particles improve. Thus, the smaller the average particle size of the dispersion medium, the more the number existing per unit volume, the greater the number of collisions, and the better the deformation and fusion properties. If it is too small, it will be difficult to separate the dispersion medium from the slurry.
  • the average particle size of the dispersion medium needs to be at least 0.03 mm or more, preferably 0.04 mm or more.
  • the average particle size of the dispersion medium is too large, the number of collisions decreases, so that the deformation and fusion property between the spherical magnetic particles deteriorates. Therefore, the upper limit of the average particle diameter of the dispersion medium is 3.0 mm.
  • a sealed container that rotates a uniaxial rotating body such as a disk, screw, blade, or pin at a high speed by rotating the dispersion medium together with the slurry is preferable. Since this hermetic container is a simple uniaxial rotation system, it is easy to increase the size and is advantageous for industrial production.
  • the above sealable container may be provided with an inlet and an outlet for introducing and discharging the slurry into and from the container, and the slurry may be circulated in the sealed container.
  • the dispersion medium is previously stored in a sealed container, and a slurry in which spherical magnetic particles, a surfactant, and a solvent are mixed is introduced from the inlet and filled so that there is no space in the container.
  • the slurry discharged from the outlet may be charged again into the sealed container.
  • the magnetic particles are not subjected to mechanical stress, and the flattened particles and spherical particles are well mixed.
  • it tends to be fine and uniform flat particles. For example, particles having a major axis of 2 ⁇ m or less and an aspect ratio of 5 or more are produced, which is a factor for reducing tan ⁇ .
  • the filling amount of the slurry and the dispersion medium into the above-mentioned closed container is the same as the volume in the closed container.
  • the slurry and the dispersion medium are filled in the sealed container without gaps.
  • the reason why the slurry and the dispersion medium are filled in the sealed container without any gap is as follows.
  • FIG. 1 is a diagram showing a state in which a slurry 3 and a dispersion medium 4 containing spherical magnetic particles 2 charged in an open container 1 having an open top are stirred at high speed by rotating at high speed with a uniaxial rotating body 5.
  • the liquid surfaces of the slurry 3 and the dispersion medium 4 have a mortar shape with a low vicinity of the central axis and a high peripheral edge due to centrifugal force.
  • the magnetic powder that is flat near the bottom of the mortar-shaped space (near the central axis) is discharged into the mortar-shaped space together with the dispersion medium and is subject to irregular impacts. May occur. Such variations in thickness, cracks, and chipping of the magnetic powder cause tan ⁇ and tan ⁇ to increase.
  • FIG. 2 is a diagram showing that the slurry 3 and the dispersion medium 4 containing the spherical magnetic particles 2 charged in the sealed container 11 are stirred at a high speed by being rotated at a high speed by the uniaxial rotating body 5.
  • the sealed container 11 is filled with the slurry 3 and the dispersion medium 4 containing the spherical magnetic particles 2, so that the mortar as seen in the open container 1 is used. There is no risk of creating a space.
  • the mechanical stress applied to the slurry 3 containing the spherical magnetic particles 2 and the dispersion medium 4 by the uniaxial rotating body 5 is uniformly propagated to the spherical magnetic particles 2 through the dispersion medium 4 in the entire sealed container 11.
  • the thickness of the obtained flat magnetic powder varies.
  • the flat magnetic powder is not subjected to irregular impacts, and there is no possibility of cracking or chipping.
  • the rotational speed of the uniaxial rotating body 5 is determined by the size of the sealed container 11.
  • the flow velocity in the vicinity of the outer peripheral end 5a in the radial direction of the uniaxial rotating body 5 of the slurry 3 and the dispersion medium 4 including the spherical magnetic particles 2 is 5 m / second or more
  • the flow velocity in the vicinity of the outer peripheral edge 5a exceeds 15 m / s, there is a risk of destroying the flattened particles because the energy is too large, so the flow velocity in the vicinity of the outer peripheral edge 5a is 15 m / s or less. Preferably there is.
  • the spherical magnetic particles 2 may remain in the obtained flat magnetic powder.
  • the remaining spherical magnetic particles 2 increase tan ⁇ and tan ⁇ by contact between the spherical magnetic particles 2 or contact between the spherical magnetic particles 2 and the flat magnetic powder.
  • the flat magnetic powder is preferably 90% by mass or more of the total amount of the magnetic powder, more preferably 95% by mass or more, and further preferably 99% by mass or more. It is desirable not to include.
  • the reason why the spherical magnetic particles 2 remain when the inner volume of the sealed container 11 is small is that the mechanical stress such as the corner of the sealed container 11 and the joint between the rotating body 5 and the sealed container 11 is not sufficiently transmitted. This is probably because the dead space becomes relatively large. Therefore, when the internal volume of the sealed container 11 is increased, the dead space is relatively reduced, and therefore, the mechanical stress is sufficiently transmitted to the spherical particles 2, and the deformation and fusion property between the spherical magnetic particles is improved. As a result, the residual spherical magnetic particles 2 are reduced, and the substantially spherical magnetic particles 2 are eliminated.
  • the volume of the sealed container 11 in which substantially spherical magnetic particles 2 do not remain is preferably 1 L or more, more preferably 5 L or more.
  • the spherical magnetic particles are deformed and fused by the mechanical stress applied by the uniaxial rotating body 5 to form a flat magnetic powder.
  • the separation method is not particularly limited as long as the solvent can be removed from the slurry after producing the flat magnetic powder, and examples thereof include heat drying, vacuum drying, freeze drying, etc., but vacuum drying in terms of drying efficiency. Is preferred.
  • some solvent may be removed by a method such as solid-liquid separation before the drying step.
  • a method of solid-liquid separation a normal method such as a filtration operation such as a filter press or suction filtration, or a centrifugal operation using a decanter or a centrifuge may be used.
  • the magnetic powder from which the solvent has been removed may be heat-treated at 50 ° C. or more and 200 ° C. or less for 1 hour or more and several hours or less. By this heat treatment, an oxide film can be formed on the surface of the flat magnetic powder, and an insulating magnetic powder can be obtained.
  • the above-mentioned flat magnetic powder is dispersed and mixed in a liquid resin or a solution obtained by dissolving a resin in a solvent to form a slurry, and this slurry is used as a molding material.
  • the resin is preferably a liquid resin, for example, polyamide resin, polyimide resin, polyamideimide resin, polyetherimide resin, polycarbonate resin, polyacetal resin, polybutylene terephthalate resin, polybenzoxazole resin, polyphenylene resin, polyphenylene resin, Benzocyclobutene resin, polyarylene ether resin, polysiloxane resin, epoxy resin, polyester resin, fluorine resin, polyolefin resin, polycycloolefin resin, cyanate resin, polyphenylene ether resin, polyphenylene sulfide resin, polyarylate resin, polyether ether ketone
  • Thermosetting resin or thermoplastic such as resin, polysulfone resin, polyethersulfone resin, norbornene resin, ABS resin, polystyrene resin Resin is preferably used.
  • the type and amount of the curing agent may be appropriately adjusted according to the type and amount of the thermosetting resin to be used.
  • the curing agent when an epoxy resin is used as the thermosetting resin, a tertiary amine is used in that the condensation reaction between the epoxy groups is promoted to prevent generation of pores due to poor curing at the time of molding the composite magnetic body. Is preferred.
  • tertiary amine examples include 1-isobutyl-2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, and the like. It is done.
  • the amount of the curing agent added is 0.5 mass% or more and 3 mass% or less based on the total mass of the thermosetting resin and the tertiary amine in consideration of promoting the condensation reaction of the functional group. You can do it. When a thermoplastic resin is used as the insulating material, no curing agent is required.
  • the solvent is not particularly limited as long as it can dissolve the above-mentioned resin.
  • alcohols such as methanol, ethanol, 2-propanol, butanol, octanol, ethyl acetate, butyl acetate
  • Esters such as ethyl lactate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ⁇ -butyrolactone, diethyl ether, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosolve), ethylene glycol monobutyl ether (Butyl cellosolve), ethers such as diethylene glycol monomethyl ether and diethylene glycol monoethyl ether, acetone, methyl ethyl ketone Preferred are ketones such as ethylene, methyl isobutyl ketone, acetylacetone and cyclo
  • the viscosity of the obtained slurry is preferably 0.1 Pa ⁇ s or more and 10 6 Pa ⁇ s or less, more preferably 0.3 Pa ⁇ s or more and 10 4 Pa ⁇ s or less.
  • the viscosity is less than 0.1 Pa ⁇ s, the fluidity becomes too high and the productivity in the drying process is deteriorated.
  • the viscosity exceeds 10 6 Pa ⁇ s, the viscosity is too high. As a result, the orientation of the magnetic powder becomes difficult to occur, and as a result, the orientation of the magnetic powder in the composite magnetic material is lowered, which is not preferable.
  • the dispersion mixing method is not particularly limited, but it is preferable to use an agitator such as a planetary mill, a sand mill capable of applying mechanical stress, or a ball mill.
  • an agitator such as a planetary mill, a sand mill capable of applying mechanical stress, or a ball mill.
  • the above molding material is molded or coated on a substrate, dried, heat-treated or fired.
  • a known molding method for example, a press method, a doctor blade method, an injection molding method or the like is suitable.
  • a dry film can be produced by forming a sheet or film of any shape using this forming method.
  • the composite magnetic body is a laminate, it is preferably formed into a sheet or film by the doctor blade method.
  • the molding material is molded after the solvent is volatilized and concentrated.
  • an orientation treatment for orienting the flat magnetic powder in a direction parallel to the sheet or film by orientation of the magnetic field may be performed before drying.
  • heat treatment or firing conditions heat treatment or hot pressing is preferable in a reducing atmosphere or in vacuum. Thereby, the composite magnetic body of this embodiment is obtained.
  • a step of pressing the molded body after the drying step When it is desired to further reduce the porosity of the molded body obtained in the drying step, it is preferable to perform a step of pressing the molded body after the drying step.
  • a known press apparatus may be used as appropriate.
  • a resin as an insulating material when applying pressure to the molded body with a press device, in order to effectively reduce pores, apply pressure in a temperature range above the softening temperature of the resin and below the curing start temperature. It is preferable.
  • a thermoplastic resin it is necessary to apply pressure at a temperature equal to or higher than the softening temperature of the resin to fuse the resins together.
  • the pressure during pressing may be appropriately adjusted according to the type of molding material, but it is preferable to apply a pressure of about 5 MPa to 20 MPa.
  • the composite magnetic body of this embodiment can also be obtained by molding a flat magnetic powder and a thermosetting resin or thermoplastic resin mixed and dispersed by heat kneading.
  • a heat-kneading method a kneaded material mixed and dispersed by a known method such as a pressure kneader, a biaxial kneader, or a blast mill can be prepared.
  • a molding method of the kneaded product a molded body can be produced by a known method such as hot press molding, extrusion molding, injection molding or the like. Among these methods, in order to orient the flat magnetic powder in the resin, hot press molding that is stretched flat is preferable.
  • a plasticizer In order to adjust the viscosity at the time of stretching, it is also preferable to add a plasticizer and perform surface treatment of the flat magnetic powder. If necessary, it is preferable to perform a treatment for orienting the flat magnetic powder by the orientation of the magnetic field in a state where the fluidity is maintained by heating.
  • a slurry and a dispersion medium obtained by dispersing spherical magnetic particles having an average particle diameter of 3 ⁇ m or less in a solution containing a surfactant are placed in a sealable container.
  • the slurry and the dispersion medium are filled so that the total volume is the same as the volume in the container, and the slurry is stirred together with the dispersion medium while applying mechanical stress (mechanical shear energy) in a sealed state.
  • the first step of deforming and fusing the spherical magnetic particles to form a flat magnetic powder, and the flat magnetic powder in a liquid resin or a solution obtained by dissolving the resin in a solvent are the first step of deforming and fusing the spherical magnetic particles to form a flat magnetic powder, and the flat magnetic powder in a liquid resin or a solution obtained by dissolving the resin in a solvent.
  • the molding material is molded or applied onto a substrate, dried, heat-treated or fired. Therefore, (1) the real part ⁇ r ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is larger than 1, the loss tangent tan ⁇ of the complex permeability is 0.02 or less, and the real part ⁇ r ′ of the complex permittivity is 50.
  • the antenna of this embodiment is an antenna that loads the above-described composite magnetic material and transmits, receives, or transmits / receives electromagnetic waves in a frequency band from 10 MHz to 70 MHz.
  • the antenna is not particularly limited as long as it is an antenna used for a non-contact IC card, and examples thereof include a loop antenna.
  • the method for loading the antenna with the composite magnetic material is not particularly limited, and may be loaded by a known method. Here, “loading” is to bring the composite magnetic body into contact with or close to the antenna conductor in order to obtain an effect such as wavelength reduction by electromagnetic interaction.
  • the real part ⁇ r ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz of this embodiment is larger than 1, the loss tangent tan ⁇ of the complex permeability is 0.02 or less, and the real part ⁇ r of the complex permittivity Since a flat composite magnetic material having 'is 50 or less and the loss tangent tan ⁇ of the complex dielectric constant is 0.2 or less is loaded, the antenna efficiency in this frequency band is increased.
  • Non-contact IC card includes the above composite magnetic body. What is necessary is just to mount said composite magnetic body on a non-contact IC card by a well-known form and method.
  • Examples of the structure of the non-contact IC card include a structure in which a back sheet, a base sheet, the composite magnetic body, and a top sheet are sequentially laminated and fixed to each other by thermocompression bonding or an adhesive.
  • the back sheet and the top sheet are not particularly limited, and a resin cosmetic exterior sheet having a thickness of about 0.1 mm to 0.2 mm can be used.
  • the base sheet is not particularly limited as long as it is an antenna used for an IC card such as a loop antenna and includes an antenna having an IC chip connected to its antenna terminal.
  • a sheet having a thickness of about 0.2 mm to 0.4 mm in which a loop antenna in which an IC chip is connected to a sheet made of resin is disposed can be used.
  • the energy of electromagnetic waves is not absorbed by the metal member, and the attenuation of the signal energy of the magnetic field lines is suppressed. can do.
  • the communication distance between the non-contact IC card and the reader or reader / writer can be increased.
  • the communication device of this embodiment includes the above composite magnetic body.
  • the communication device is not particularly limited as long as it can be used with a built-in IC card, and examples thereof include information terminal devices such as a mobile phone, a portable information terminal, and a multifunctional portable information terminal.
  • the method of disposing the above composite magnetic body in the communication device is not particularly limited, and may be disposed by a known method.
  • the structure which provided the said composite magnetic body between the IC card which has an antenna, and a metal member is mentioned.
  • the structure which provided the composite magnetic body between the antenna provided in the base sheet of the IC card and the metal member by arranging the surface sheet of the non-contact IC card so as to face the metal member. .
  • the energy of electromagnetic waves is not absorbed by the metal member in the communication device, and the signal energy of the magnetic field lines is attenuated. Can be suppressed. As a result, the communication distance between the communication device and the reader or reader / writer can be increased.
  • the magnetic powder is made flat, and the magnetic properties thereof are as follows: (1) the real part ⁇ r ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is greater than 1, Permeability loss tangent tan ⁇ is 0.02 or less, complex permittivity real part ⁇ r ′ is 50 or less, loss tangent tan ⁇ of complex permittivity is 0.2 or less, and (2) complex permeability in the frequency band from 10 MHz to 20 MHz.
  • Real part ⁇ r ′ of magnetic susceptibility is greater than 1, loss tangent tan ⁇ of complex permeability is 0.01 or less, real part ⁇ r ′ of complex permittivity is 50 or less, loss tangent tan ⁇ of complex permittivity is 0.2 or less, Either. Thereby, attenuation
  • the thickness of the magnetic powder is 0.01 ⁇ m or more and 10 ⁇ m or less, the average major axis is 0.05 ⁇ m or more and 20 ⁇ m or less, and the average aspect ratio (major axis / thickness) is 5 or more, the frequency ranges from 10 MHz to 70 MHz.
  • a composite magnetic body having a real part ⁇ r ′ of complex permeability in the frequency band of 4 or more and a real part ⁇ r ′ of complex permittivity of 50 or less can be obtained.
  • the magnetic powder is made of aluminum (Al), chromium (Cr), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), niobium (Nb), molybdenum (Mo), indium (In ) And an iron-nickel alloy containing one or more metal elements selected from the group of tin (Sn), a high ⁇ r ′ composite magnetic body can be obtained.
  • the above magnetic powder may be a magnetic powder obtained by applying mechanical stress to spherical magnetic particles having an average particle diameter of 3 ⁇ m or less and deforming and fusing the spherical magnetic particles together.
  • a composite magnetic body having a high aspect ratio, that is, a high ⁇ r ′ can be obtained.
  • a slurry and a dispersion medium obtained by dispersing spherical magnetic particles having an average particle diameter of 3 ⁇ m or less in a solution containing a surfactant are placed in a sealable container.
  • the slurry and the dispersion medium are filled so that the total volume is the same as the volume in the container, and the slurry is stirred together with the dispersion medium in a sealed state to deform and fuse the spherical magnetic particles with each other.
  • a flat composite magnetic body substantially free of spherical magnetic particles can be obtained, so that a flat shape with a larger ⁇ r ′ is obtained.
  • a composite magnetic body can be obtained.
  • the antenna efficiency can be improved. .
  • the non-contact IC card of the present embodiment since the composite magnetic body of the present embodiment is provided, even if a metal member is present on the surface side of the non-contact IC card, the signal energy of magnetic field lines is attenuated by the metal member. Can be suppressed. As a result, the communication distance between the non-contact IC card and the reader or reader / writer can be increased.
  • the composite magnetic body is provided between the antenna and the metal member, the energy of electromagnetic waves is not absorbed by the metal member, and the performance as a magnetic shield material is maintained. The attenuation of the signal energy of the magnetic lines of force can be suppressed. As a result, the communication distance between the communication device and the reader or reader / writer can be increased.
  • Example 1 "First step" 200 g of spherical magnetic particles having an average particle diameter of 0.25 ⁇ m made of Ni—Fe—Zn alloy of Ni 75 mass% —Fe 20 mass% —Zn 5 mass% are mixed with 800 g of xylene in which a nitrogen-containing graft polymer is dissolved as a surfactant. Thus, a slurry was prepared. Next, a sand mill Ultra Apex Mill UAM-5 (manufactured by Kotobuki Kogyo Co., Ltd.) having a circulation volume of 5 L and having a volume of 5 L as shown in FIG. 2 is used as the hermetic container. Zirconia beads were charged, and then the above slurry was charged to fill the sealed container.
  • a sand mill Ultra Apex Mill UAM-5 manufactured by Kotobuki Kogyo Co., Ltd.
  • stirring is performed at a rotational speed such that the flow velocity near the radial outer periphery of the uniaxial rotating body is 10 m / second or more, the average thickness is 0.3 ⁇ m, the average major axis is 2.8 ⁇ m, and the average aspect ratio is 9 .3 flat magnetic powder was produced.
  • this flat magnetic powder is added to a resin solution obtained by dissolving polystyrene resin in toluene. Stir and mix.
  • the magnetic powder was mixed so as to be 40% by volume in the total volume of the magnetic powder and the polystyrene resin.
  • ⁇ r ′, ⁇ r ′′, tan ⁇ , ⁇ r ′, ⁇ r ′′, and tan ⁇ of this composite magnetic material at 10 to 100 MHz were measured with a material analyzer E4991A type (manufactured by Agilent Technologies).
  • the measurement results of the real part ⁇ r ′ of the complex permeability, the imaginary part ⁇ r ′′ of the complex permeability, and the loss tangent tan ⁇ of the complex permeability are shown in FIG. 3, the real part ⁇ r ′ of the complex permittivity, the imaginary part ⁇ r ′′ of the complex permittivity 4 shows the measurement results of the loss tangent tan ⁇ of the complex dielectric constant.
  • ⁇ r ′ was 9, ⁇ r ′′ was 0.08, tan ⁇ was 0.009, ⁇ r ′ was 25.7, ⁇ r ′′ was 2.8, and tan ⁇ was 0.11.
  • the average thickness of 50 flat magnetic powders was 0.3 ⁇ m, and the average major axis was 2.8 ⁇ m.
  • the average value of the individual aspect ratios was 9.3. Further, only a flat magnetic powder is observed within the field of view of this scanning electron microscope image (SEM image), and the spherical magnetic particles and the flat magnetic powder have a thickness, length or aspect ratio. Magnetic particles deviating from the above were not substantially observed.
  • Comparative Example 1 200 g of spherical magnetic particles having an average particle diameter of 0.25 ⁇ m (aspect ratio: 1) made of Ni—Fe—Zn alloy of Ni 75 mass% —Fe 20 mass% —Zn 5 mass%, and a nitrogen-containing graft polymer as a surfactant A slurry was prepared by mixing with 800 g of dissolved xylene. Next, in the same manner as in Example 1, a predetermined amount of the flat magnetic powder was added to a resin solution obtained by dissolving a polystyrene resin in toluene and mixed with stirring. Here, the magnetic powder was mixed so as to be 40% by volume in the total volume of the magnetic powder and the polystyrene resin.
  • the obtained mixture was formed into a square film having a 100 mm square and a thickness of 600 ⁇ m by the doctor blade method in the same manner as in Example 1.
  • this film was dried in the atmosphere at 80 ° C. for 20 minutes to obtain a dry film having a thickness of 100 ⁇ m, and then press firing was performed with a reduced-pressure press apparatus.
  • the pressing condition was that the temperature was raised to 90 ° C. over 20 minutes at normal pressure, and then a pressure of 2 MPa was applied and held for 10 minutes to obtain a composite magnetic body of Comparative Example 1.
  • ⁇ r ′, ⁇ r ′′ and tan ⁇ of this composite magnetic material from 10 MHz to 100 MHz were measured with a material analyzer E4991A type (manufactured by Agilent Technologies), ⁇ r ′ at 13.56 MHz was 3.8, and ⁇ r ′′ was 0.28. , Tan ⁇ was 0.07.
  • Example 2 An IC card of Example 2 was obtained by sequentially laminating a back sheet, a base sheet having a loop antenna to which an IC chip was connected, a composite magnetic body of Example 1, and a top sheet, and fixing them.
  • Comparative Example 2 instead of using the composite magnetic material of Example 1, an IC card of Comparative Example 2 was obtained in the same manner as Example 2 except that the composite magnetic material of Comparative Example 1 was used.
  • the IC card of Example 2 was the IC card of Comparative Example 2 It was confirmed that the communication distance was longer than that.
  • Example 3 "First step" Instead of spherical magnetic particles with an average particle diameter of 0.25 ⁇ m consisting of Ni—Fe—Zn alloy of Ni 75 mass% —Fe 20 mass% —Zn 5 mass%, an average consisting of Ni—Fe alloy of Ni 78 mass% —Fe 22 mass% A magnetic powder of Example 3 was obtained in the same manner as in the first step of Example 1, except that spherical magnetic particles having a particle size of 0.3 ⁇ m were used. The obtained magnetic powder had a flat shape with an average thickness of 0.2 ⁇ m, an average major axis of 1.9 ⁇ m, and an average aspect ratio of 9.5.
  • Example 3 "Second and third steps" Using this flat magnetic powder, a composite magnetic body of Example 3 was obtained in the same manner as in the second and third steps of Example 1. ⁇ r ′, ⁇ r ′′, tan ⁇ , ⁇ r ′, ⁇ r ′′ and tan ⁇ at 13.56 MHz of this composite magnetic material were measured in the same manner as in Example 1. As a result, ⁇ r ′ was 10 and ⁇ r ′′ was 0. 08, tan ⁇ was 0.008, ⁇ r ′ was 24.6, ⁇ r ′′ was 2.7, and tan ⁇ was 0.11.
  • the average thickness of 50 flat magnetic powders was 0.2 ⁇ m, and the average major axis was 1.9 ⁇ m.
  • the average value of the individual aspect ratios was 9.5. Further, only the flat magnetic powder is recognized within the field of view of the scanning electron microscope image (SEM image), and the spherical magnetic particles or the flat magnetic powder having the thickness, length or aspect ratio described above are used. Magnetic particles deviating from the above were not observed.
  • Example 4 "First step" Instead of spherical magnetic particles with an average particle diameter of 0.25 ⁇ m consisting of Ni—Fe—Zn alloy of Ni 75 mass% —Fe 20 mass% —Zn 5 mass%, an average consisting of Ni—Fe alloy of Ni 78 mass% —Fe 22 mass% A magnetic powder of Example 4 was obtained in the same manner as in the first step of Example 1, except that spherical magnetic particles having a particle diameter of 0.3 ⁇ m were used. The obtained magnetic powder had a flat shape with an average thickness of 0.2 ⁇ m, an average major axis of 1.9 ⁇ m, and an average aspect ratio of 9.5.
  • ⁇ r ′, ⁇ r ′′, tan ⁇ , ⁇ r ′, ⁇ r ′′, and tan ⁇ of this composite magnetic material were measured in the same manner as in Example 1.
  • ⁇ r ′ was 10
  • ⁇ r ′′ was 0.08
  • tan ⁇ was 0.008
  • ⁇ r ′ was 30.3, ⁇ r ′′ was 3.8
  • tan ⁇ was 0.13.
  • the average thickness of 50 flat magnetic powders was 0.2 ⁇ m, and the average major axis was 1.9 ⁇ m.
  • the average value of the individual aspect ratios was 9.5. Further, only flat magnetic powder is recognized within the field of view of this scanning electron microscope image (SEM image), and spherical magnetic particles and the above-mentioned flat magnetic powder having a thickness, a long diameter or an aspect ratio of Magnetic particles deviating from the above were not observed.
  • spherical magnetic particles (aspect ratio: 1) composed of Ni-Fe alloy of Ni 78 mass% -Fe 22 mass% and having an average particle diameter of 0.3 ⁇ m are mixed with 800 g of xylene in which a nitrogen-containing graft polymer is dissolved as a surfactant. Thus, a slurry was prepared.
  • a predetermined amount of the flat magnetic powder was added to a resin solution obtained by dissolving a polystyrene resin in toluene and mixed with stirring. Here, mixing was performed so that the total volume of the magnetic powder was 40% by volume with respect to the polystyrene resin.
  • a composite magnetic body of Comparative Example 3 was obtained in the same manner as Example 1 using the obtained mixture.
  • This composite magnetic body had a ⁇ r ′ of 3.1, a ⁇ r ′′ of 0.27, and a tan ⁇ of 0.09 at 13.56 MHz.
  • Example 5 An IC card of Example 5 was obtained by sequentially laminating a back sheet, a base sheet having a loop antenna to which an IC chip was connected, a composite magnetic body of Example 3, and a top sheet, and fixing them.
  • Example 6 An IC card of Example 6 was obtained by sequentially laminating a back sheet, a base sheet having a loop antenna to which an IC chip was connected, a composite magnetic body of Example 4, and a top sheet, and fixing them.

Abstract

This composite magnet is made by dispersing a magnetic powder in an insulating material, wherein the magnetic powder is flat in shape, the real part µr' of the complex magnetic permeability in a frequency range of 10 MHz to 70 MHz is greater than 1, the loss tangent tanδµ of the complex magnetic permeability is 0.02 or less, the real part εr' of the complex dielectric constant is 50 or less, and the loss tangent tanδε of the complex dielectric constant is 0.2 or less.

Description

複合磁性体及びそれを備えたアンテナ並びに非接触ＩＣカードCOMPOSITE MAGNETIC MATERIAL AND ANTENNA WITH THE SAME AND NON-CONTACT IC CARD
　本発明は、複合磁性体及びそれを備えたアンテナ並びに非接触ＩＣカードに関し、特に、１０ＭＨｚから７０ＭＨｚまでの周波数帯域の電磁波を利用するアンテナへの装荷、あるいは、この周波数帯域の電磁波を利用する電子部品を構成する磁性材料として用いて好適な複合磁性体、及び、この複合磁性体を備えたアンテナ、並びに、この複合磁性体を備えた非接触ＩＣカードに関する。
　本願は、２０１１年１１月２１日に、日本に出願された特願２０１１－２５４１７０号、及び２０１２年５月２９日に、日本に出願された特願２０１２－１２２５２７号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a composite magnetic body, an antenna including the same, and a non-contact IC card, and more particularly, loading to an antenna using an electromagnetic wave in a frequency band from 10 MHz to 70 MHz, or an electronic using an electromagnetic wave in this frequency band. The present invention relates to a composite magnetic body suitable for use as a magnetic material constituting a component, an antenna including the composite magnetic body, and a non-contact IC card including the composite magnetic body.
This application claims priority based on Japanese Patent Application No. 2011-254170 filed in Japan on November 21, 2011 and Japanese Patent Application No. 2012-122527 filed in Japan on May 29, 2012. , The contents of which are incorporated herein.
　ＲＦＩＤ（Radio Frequency Identification）は、無線タグとも称され、近距離の無線通信により情報を送受信することのできる技術であり、非接触ＩＣカード等に用いられている。この非接触ＩＣカードは、ＩＣタグとも称され、交通機関の乗車カードや電子マネーとして広く用いられている。
　この非接触ＩＣカードを用いた通信手段としては、非接触ＩＣカードに内蔵されたコイルと、リーダーまたはリーダー／ライターに内蔵されたコイルとの磁束結合による電磁誘導方式がよく用いられている。そこで使われている周波数は１３．５６ＭＨｚが多い。 RFID (Radio Frequency Identification), also called a wireless tag, is a technology that can transmit and receive information by short-range wireless communication, and is used for non-contact IC cards and the like. This non-contact IC card is also called an IC tag, and is widely used as a transportation card or electronic money.
As a communication means using this non-contact IC card, an electromagnetic induction method based on magnetic flux coupling between a coil built in the non-contact IC card and a coil built in the reader or reader / writer is often used. The frequency used there is often 13.56 MHz.
　電磁誘導方式では、非接触ＩＣカードの近傍に金属が有ると、磁力線がその金属内を通過する際に渦電流を発生させ、この磁力線の信号エネルギーの一部が渦電流の発生の際に熱エネルギーに変化し、この熱エネルギーが金属に吸収されてしまうという問題点があった。この磁力線の信号エネルギーの一部が熱エネルギーとして金属に吸収されると、磁力線の信号エネルギーが大きく減衰して、通信に必要なエネルギーを確保することができなくなり、その結果、無線通信による情報の送受信ができなくなることとなる。
　そのため、非接触ＩＣカードを用いる際には、その近傍に金属を設置させることができず、非接触ＩＣカードを金属部材を有する通信装置内に配置させることができないという問題点があった。 In the electromagnetic induction method, if there is a metal near the non-contact IC card, an eddy current is generated when the magnetic field lines pass through the metal, and a part of the signal energy of the magnetic field line is heated when the eddy current is generated. There is a problem that the heat energy is absorbed by the metal. When a part of the signal energy of the magnetic field lines is absorbed by the metal as heat energy, the signal energy of the magnetic field lines is greatly attenuated, and it becomes impossible to secure the energy necessary for communication. It becomes impossible to send and receive.
For this reason, when a non-contact IC card is used, there is a problem in that a metal cannot be installed in the vicinity thereof, and the non-contact IC card cannot be arranged in a communication device having a metal member.
　そこで、この問題を解決するために、非接触ＩＣカードと金属部材の間に、複素透磁率の実部μｒ’（以下μｒ’と略記する場合がある）が大きい磁気シールド層を有する磁気シールドシートを配設した構造が提案されている（特許文献１）。
　この構造では、磁力線が磁気シールドシートを通過する際に、磁気シールド層に集中して通過するようになるので、金属部材への磁力線の漏れを防ぐことができる。 Therefore, in order to solve this problem, a magnetic shield sheet having a magnetic shield layer having a large real part μr ′ of complex permeability (hereinafter sometimes abbreviated as μr ′) between the non-contact IC card and the metal member. The structure which arrange | positioned is proposed (patent document 1).
In this structure, when the magnetic field lines pass through the magnetic shield sheet, the magnetic field lines concentrate and pass through the magnetic shield layer, so that leakage of the magnetic field lines to the metal member can be prevented.
特許第３６４７４４６号公報Japanese Patent No. 3647446
　しかしながら、上述した磁気シールドシートを用いた場合、複素透磁率の虚部μｒ”（以下μｒ”と略記する場合がある）、複素誘電率の実部εｒ’（以下εｒ’と略記する場合がある）、複素誘電率の虚部εｒ”（以下εｒ”と略記する場合がある）が大きいことから、磁力線の信号エネルギーが減衰してしまうという問題点があった。
　そのために、μｒ’が大きいことから金属部材による磁力線の信号エネルギー損失を抑制することができても、μｒ”、εｒ’、εｒ”が大きいことによる信号エネルギーの減衰により、通信状態が悪化するという問題点があった。
　なお、複素透磁率とは、磁性体に交番磁場Ｈをかけ、磁束密度Ｂの変化に位相的な遅れが出る場合、Ｂとμ0Ｈの比、μｒ＝Ｂ／μ0Ｈ＝μｒ’－ｊμｒ”をいう。（μ0は真空の透磁率）また、複素誘電率とは、誘電体に交番電場Ｅをかけ、電束密度Ｄの変化に位相的な遅れが出る場合、Ｄとε0Ｅの比、εｒ＝Ｄ／ε0Ｅ＝εｒ’－ｊεｒ”をいう。（ε0は真空の誘電率） However, when the above-described magnetic shield sheet is used, the complex permeability imaginary part μr ″ (hereinafter sometimes abbreviated as μr ″) and the complex dielectric constant real part εr ′ (hereinafter abbreviated as εr ′) may be sometimes used. ), Since the imaginary part εr ″ (hereinafter sometimes abbreviated as εr ″) of the complex dielectric constant is large, there is a problem that the signal energy of the magnetic field lines is attenuated.
Therefore, even if it is possible to suppress the signal energy loss of the magnetic force lines due to the metal member because μr ′ is large, the communication state deteriorates due to the attenuation of signal energy due to the large μr ″, εr ′, εr ″. There was a problem.
Note that the complex permeability is the ratio of B to μ 0 H, where μr = B / μ 0 H = μr′−, in the case where an alternating magnetic field H is applied to the magnetic material and a change in the magnetic flux density B is delayed in phase. jμr ″. (μ 0 is the permeability of the vacuum) Further, the complex dielectric constant means that when an alternating electric field E is applied to the dielectric and a phase delay occurs in the change of the electric flux density D, D and ε 0 E ratio, εr = D / ε 0 E = εr′−jεr ″. (Ε 0 is the dielectric constant of the vacuum)
　特許文献１では、最適な磁気シールドシートの条件として、１３．５６ＭＨｚにて、μｒ’＝６１、μｒ”＝３が例示されているが、この例の場合、磁力線の信号エネルギーの減衰量を示す複素透磁率の損失正接ｔａｎδμ(＝μｒ”／μｒ’)（以下、ｔａｎδμと略記する場合がある）が０．０５と大きかった。さらに、１０ＭＨｚから７０ＭＨｚまでの周波数帯域におけるεｒ’が１００以上、εｒ”が６０以上と大きかった。したがって、非接触ＩＣカードのデータを正確に読み取るためには、非接触ＩＣカードとリーダーまたはリーダー／ライターとの通信距離を一定の範囲内に近づける必要があった。そこで、非接触ＩＣカードとリーダーまたはリーダー／ライターとの通信距離を長く取ることができるように、μｒ’が大きく、かつ、ｔａｎδμ、εｒ’、複素誘電率の損失正接ｔａｎδε（＝εｒ”／εｒ’）（以下、ｔａｎδεと略記する場合がある）の低い磁気シールドシートが望まれていた。 In Patent Document 1, μr ′ = 61 and μr ″ = 3 are exemplified at 13.56 MHz as the optimum magnetic shield sheet conditions. In this example, the attenuation amount of the signal energy of the magnetic field lines is shown. The loss tangent tan δμ (= μr ″ / μr ′) of complex permeability (hereinafter sometimes abbreviated as tan δμ) was as large as 0.05. Furthermore, in the frequency band from 10 MHz to 70 MHz, εr ′ was 100 or more and εr ″ was 60 or more. Therefore, in order to accurately read the data of the noncontact IC card, the noncontact IC card and the reader / reader / reader / Since it was necessary to make the communication distance with the writer within a certain range, μr ′ is large and tan δμ so that the communication distance between the non-contact IC card and the reader or the reader / writer can be increased. , Εr ′, loss tangent of complex dielectric constant tan δε (= εr ″ / εr ′) (hereinafter, sometimes abbreviated as tan δε) has been desired.
　本発明は、上記事情に鑑みてなされたものであって、１０ＭＨｚから７０ＭＨｚまでの周波数帯域に適用可能であり、しかも、この周波数帯域における複素透磁率の実部μｒ’が大きく、かつ複素透磁率の損失正接ｔａｎδμ、複素誘電率の実部εｒ’及び複素誘電率の損失正接ｔａｎδεが低い複合磁性体及びそれを備えたアンテナ並びに非接触ＩＣカードを提供することを目的とする。 The present invention has been made in view of the above circumstances, and can be applied to a frequency band from 10 MHz to 70 MHz. Moreover, the real part μr ′ of the complex permeability in this frequency band is large, and the complex permeability. It is an object of the present invention to provide a composite magnetic body having a low loss tangent tan δμ, a real part εr ′ of a complex dielectric constant and a loss tangent tan δε of a complex dielectric constant, an antenna including the same, and a contactless IC card.
　本発明者等は、上記課題を解決するために鋭意検討を行った。その結果、磁性粉体を絶縁材料中に分散させた複合磁性体における前記磁性粉体の形状を扁平状とし、この複合磁性体の１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’を１よりも大きく、複素透磁率の損失正接ｔａｎδμを０．０２以下、複素誘電率の実部εｒ’を５０以下、複素誘電率の損失正接ｔａｎδεを０．２以下とするか、または、１０ＭＨｚから２０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’を１よりも大きく、複素透磁率の損失正接ｔａｎδμを０．０１以下、複素誘電率の実部εｒ’を５０以下、複素誘電率の損失正接ｔａｎδεを０．２以下とすれば、この複合磁性体を非接触ＩＣカードに適用することが可能となり、その結果、非接触ＩＣカードとリーダーまたはリーダー／ライターとの通信距離を長く取ることが可能であることを見出し、本発明を完成するに至った。 The inventors of the present invention have made extensive studies to solve the above problems. As a result, the shape of the magnetic powder in the composite magnetic body in which the magnetic powder is dispersed in the insulating material is flattened, and the real part μr ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz of the composite magnetic body. Is greater than 1, the loss tangent tan δμ of the complex permeability is 0.02 or less, the real part εr ′ of the complex permittivity is 50 or less, and the loss tangent tan δε of the complex permittivity is 0.2 or less, or 10 MHz The real part μr ′ of the complex permeability in the frequency band from 1 to 20 MHz is greater than 1, the loss tangent tan δμ of the complex permeability is 0.01 or less, the real part εr ′ of the complex permittivity is 50 or less, and the complex permittivity If the loss tangent tan δε is 0.2 or less, this composite magnetic body can be applied to a non-contact IC card. As a result, the non-contact IC card and the reader or reader / writer It found that it is possible to take the communication distance to the long, and have completed the present invention.
　すなわち、本発明の複合磁性体は、磁性粉体を絶縁材料中に分散してなる複合磁性体において、前記磁性粉体は扁平状であり、１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’は１よりも大きく、複素透磁率の損失正接ｔａｎδμは０．０２以下、複素誘電率の実部εｒ’は５０以下、複素誘電率の損失正接ｔａｎδεは０．２以下であることを特徴とする。 That is, the composite magnetic body of the present invention is a composite magnetic body in which magnetic powder is dispersed in an insulating material, and the magnetic powder is flat and has a complex permeability in a frequency band from 10 MHz to 70 MHz. The part μr ′ is larger than 1, the loss tangent tan δμ of the complex permeability is 0.02 or less, the real part εr ′ of the complex permittivity is 50 or less, and the loss tangent tan δε of the complex permittivity is 0.2 or less. Features.
　本発明の他の複合磁性体は、磁性粉体を絶縁材料中に分散してなる複合磁性体において、前記磁性粉体は扁平状であり、１０ＭＨｚから２０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’は１よりも大きく、複素透磁率の損失正接ｔａｎδμは０．０１以下、複素誘電率の実部εｒ’は５０以下、複素誘電率の損失正接ｔａｎδεは０．２以下であることを特徴とする。 Another composite magnetic body of the present invention is a composite magnetic body in which magnetic powder is dispersed in an insulating material, and the magnetic powder is flat and has a complex permeability in a frequency band from 10 MHz to 20 MHz. The part μr ′ is larger than 1, the loss tangent tanδμ of the complex permeability is 0.01 or less, the real part εr ′ of the complex permittivity is 50 or less, and the loss tangent tanδε of the complex permittivity is 0.2 or less. Features.
　本発明の複合磁性体では、前記磁性粉体の平均厚みは０．０１μｍ以上かつ１０μｍ以下、平均長径は０．０５μｍ以上かつ２０μｍ以下、かつ平均アスペクト比（長径／厚み）は５以上であることが好ましい。
　前記磁性粉体は、アルミニウム（Ａｌ）、クロム（Ｃｒ）、マンガン（Ｍｎ）、コバルト（Ｃｏ）、銅（Ｃｕ）、亜鉛（Ｚｎ）、ニオブ（Ｎｂ）、モリブデン（Ｍｏ）、インジウム（Ｉｎ）、スズ（Ｓｎ）の群から選択される１種または２種以上の金属元素を含む鉄－ニッケル合金であることが好ましい。
　前記磁性粉体は、平均粒子径が３μｍ以下の球状の磁性粒子に機械的応力を加えることにより、この球状の磁性粒子同士を変形及び融着してなることが好ましい。 In the composite magnetic body of the present invention, the magnetic powder has an average thickness of 0.01 μm to 10 μm, an average major axis of 0.05 μm to 20 μm, and an average aspect ratio (major axis / thickness) of 5 or more. Is preferred.
The magnetic powder includes aluminum (Al), chromium (Cr), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), niobium (Nb), molybdenum (Mo), and indium (In). An iron-nickel alloy containing one or more metal elements selected from the group of tin (Sn) is preferable.
The magnetic powder is preferably formed by deforming and fusing the spherical magnetic particles by applying mechanical stress to the spherical magnetic particles having an average particle diameter of 3 μm or less.
　本発明のアンテナは、本発明の複合磁性体を装荷してなり、１０ＭＨｚから７０ＭＨｚまでの周波数帯域の電波を、送信、受信または送受信することを特徴とする。 The antenna of the present invention is loaded with the composite magnetic material of the present invention, and is characterized by transmitting, receiving or transmitting / receiving radio waves in a frequency band from 10 MHz to 70 MHz.
　本発明の非接触ＩＣカードは、本発明の複合磁性体を備えてなることを特徴とする。 The non-contact IC card of the present invention comprises the composite magnetic body of the present invention.
　本発明の複合磁性体によれば、磁性粉体を扁平状とし、さらに、１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’を１よりも大きく、複素透磁率の損失正接ｔａｎδμを０．０２以下、複素誘電率の実部εｒ’を５０以下、複素誘電率の損失正接ｔａｎδεを０．２以下としたので、この周波数帯域における磁力線の信号エネルギーの減衰を抑制することができる。 According to the composite magnetic body of the present invention, the magnetic powder is flattened, and the real part μr ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is larger than 1, and the loss tangent tan δμ of the complex permeability is Since 0.02 or less, the real part εr ′ of the complex dielectric constant is 50 or less, and the loss tangent tan δε of the complex dielectric constant is 0.2 or less, it is possible to suppress the attenuation of the signal energy of the magnetic field lines in this frequency band.
　本発明のアンテナによれば、本発明の複素透磁率を備えたので、１０ＭＨｚから７０ＭＨｚまでの周波数帯域におけるアンテナ効率を高めることができる。 According to the antenna of the present invention, since the complex magnetic permeability of the present invention is provided, the antenna efficiency in the frequency band from 10 MHz to 70 MHz can be increased.
　本発明の非接触ＩＣカードによれば、本発明の複合磁性体を備えたので、１０ＭＨｚから７０ＭＨｚまでの周波数帯域における磁力線の信号エネルギーの減衰を抑制することができる。したがって、非接触ＩＣカードとリーダーまたはリーダー／ライターとの通信距離を長く取ることができる。 According to the non-contact IC card of the present invention, since the composite magnetic body of the present invention is provided, the attenuation of the signal energy of the magnetic field lines in the frequency band from 10 MHz to 70 MHz can be suppressed. Therefore, the communication distance between the non-contact IC card and the reader or reader / writer can be increased.
開放容器を用いて球状の磁性粒子を含むスラリー及び分散媒体を高速撹拌する様を示す図である。It is a figure which shows a mode that the slurry containing a spherical magnetic particle and dispersion medium are stirred at high speed using an open container. 密閉容器を用いて球状の磁性粒子を含むスラリー及び分散媒体を高速撹拌する様を示す図である。It is a figure which shows a mode that the slurry and dispersion medium containing a spherical magnetic particle are stirred at high speed using an airtight container. 本発明の実施例１の複合磁性体の複素透磁率の実部μｒ’、複素透磁率の虚部μｒ”及び複素透磁率の損失正接ｔａｎδμを示す図である。It is a figure which shows the real part μr ′ of the complex permeability, the imaginary part μr ″ of the complex permeability, and the loss tangent tan δμ of the complex permeability of the composite magnetic body of Example 1 of the present invention. 本発明の実施例１の複合磁性体の複素誘電率の実部εｒ’、複素誘電率の虚部εｒ”及び複素誘電率の損失正接ｔａｎδεを示す図である。It is a figure which shows the real part εr 'of the complex dielectric constant, the imaginary part εr' 'of the complex dielectric constant, and the loss tangent tan δε of the complex dielectric constant of the composite magnetic body of Example 1 of the present invention.
　本発明の複合磁性体及びそれを備えたアンテナ並びに非接触ＩＣカードを実施するための形態について説明する。
　この形態は、発明の趣旨をより良く理解させるために具体的に説明するものであり、特に指定のない限り、本発明を限定するものではない。本発明の趣旨を逸脱しない範囲で、構成の付加、省略、置換、およびその他の変更が可能である。 An embodiment for carrying out the composite magnetic body of the present invention, an antenna including the same, and a non-contact IC card will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention.
［複合磁性体］
　本実施形態の複合磁性体は、磁性粉体を絶縁材料中に分散してなる複合磁性体において、この磁性粉体は扁平状であり、次の（１）の磁気特性を有する。
（１）１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’は１よりも大きく、複素透磁率の損失正接ｔａｎδμは０．０２以下、複素誘電率の実部εｒ’は５０以下、複素誘電率の損失正接ｔａｎδεは０．２以下である。
　本実施形態の複合磁性体は、次の（２）の磁気特性を有することとしてもよい。
（２）１０ＭＨｚから２０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’は１よりも大きく、複素透磁率の損失正接ｔａｎδμは０．０１以下、複素誘電率の実部εｒ’は５０以下、複素誘電率の損失正接ｔａｎδεは０．２以下である。 [Composite magnetic material]
The composite magnetic body of this embodiment is a composite magnetic body in which magnetic powder is dispersed in an insulating material. This magnetic powder is flat and has the following magnetic characteristics (1).
(1) The real part μr ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is greater than 1, the loss tangent tan δμ of the complex permeability is 0.02 or less, the real part εr ′ of the complex permittivity is 50 or less, The loss tangent tan δε of the complex dielectric constant is 0.2 or less.
The composite magnetic body of the present embodiment may have the following magnetic property (2).
(2) The real part μr ′ of the complex permeability in the frequency band from 10 MHz to 20 MHz is larger than 1, the loss tangent tan δμ of the complex permeability is 0.01 or less, the real part εr ′ of the complex permittivity is 50 or less, The loss tangent tan δε of the complex dielectric constant is 0.2 or less.
　この複合磁性体では、１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’は４以上が好ましく、６以上がより好ましい。１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の損失正接ｔａｎδμは０．０２以下が好ましく、０．０１５以下がより好ましい。また、１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素誘電率の実部εｒ’は３０以下が好ましい。１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素誘電率の損失正接ｔａｎδεは０．１以下が好ましく、０．０５以下がより好ましい。
　ここで、複素透磁率の実部μｒ’、複素透磁率の損失正接ｔａｎδμ、複素誘電率の実部εｒ’及び複素誘電率の損失正接ｔａｎδεを上記の範囲に限定した理由は、これらの範囲が、複合磁性体が磁気シールドの性能を保ちつつ、磁力線の信号エネルギーの減衰を抑制することができる範囲だからである。 In this composite magnetic body, the real part μr ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is preferably 4 or more, and more preferably 6 or more. The loss tangent tan δμ of the complex permeability in the frequency band from 10 MHz to 70 MHz is preferably 0.02 or less, and more preferably 0.015 or less. The real part εr ′ of the complex dielectric constant in the frequency band from 10 MHz to 70 MHz is preferably 30 or less. The loss tangent tan δε of the complex dielectric constant in the frequency band from 10 MHz to 70 MHz is preferably 0.1 or less, and more preferably 0.05 or less.
Here, the real part μr ′ of the complex permeability, the loss tangent tan δμ of the complex permeability, the real part εr ′ of the complex permittivity, and the loss tangent tan δ∈ of the complex permittivity are limited to the above ranges. This is because the composite magnetic body can suppress the signal energy attenuation of the magnetic field lines while maintaining the performance of the magnetic shield.
　この複合磁性体の形状や厚みは特に限定されず、用途に応じて適宜変更すればよいが、例えば、１０ＭＨｚから７０ＭＨｚまでの周波数帯域にて優れた磁気特性を得るためには、複合磁性体の厚みは１０μｍ以上かつ１ｍｍ以下程度にすることが好ましい。
　上記のμｒ’、εｒ’、ｔａｎδμ及びｔａｎδεはマテリアルアナライザーにて測定した値であるが、測定装置としては、上記の各値がマテリアルアナライザーと同等の精度で測定することのできる装置であればよく、マテリアルアナライザーに限定されない。 The shape and thickness of the composite magnetic body are not particularly limited and may be appropriately changed depending on the application. For example, in order to obtain excellent magnetic characteristics in a frequency band from 10 MHz to 70 MHz, the composite magnetic body The thickness is preferably about 10 μm to 1 mm.
The above μr ′, εr ′, tan δμ and tan δε are values measured by a material analyzer, but any measuring device can be used as long as each of the above values can be measured with the same accuracy as the material analyzer. Not limited to material analyzers.
「磁性粉体」
　本実施形態の磁性粉体を構成する材料としては、磁性を有する材料であればよく、特に限定されないが、例えば、ニッケル（Ｎｉ）、鉄（Ｆｅ）、コバルト（Ｃｏ）、ガドリニウム（Ｇｄ）、テルビウム（Ｔｂ）、ジスプロシウム（Ｄｙ）等の強磁性金属、モリブデン（Ｍｏ）等の常磁性金属のうちいずれか１種からなる金属、または、これらのうち少なくとも１種以上を含む合金を用いることができる。
　これらの金属または合金は、反磁性金属である銅（Ｃｕ）、亜鉛（Ｚｎ）、ビスマス（Ｂｉ）等を含んでいてもよい。 "Magnetic powder"
The material constituting the magnetic powder of the present embodiment is not particularly limited as long as it is a material having magnetism. For example, nickel (Ni), iron (Fe), cobalt (Co), gadolinium (Gd), Use of a ferromagnetic metal such as terbium (Tb) or dysprosium (Dy), a metal composed of any one of paramagnetic metals such as molybdenum (Mo), or an alloy containing at least one of these metals. it can.
These metals or alloys may contain diamagnetic metals such as copper (Cu), zinc (Zn), and bismuth (Bi).
　これらの合金としては、二元素系合金、三元素系合金等が挙げられる。
　二元素系合金としては、保磁力が７０エルステッド（Ｏｅ）以下の軟磁性を示すパーマロイ（登録商標）等のＦｅ－Ｎｉ合金、Ｆｅ－Ｓｉ合金、Ｆｅ－Ｃｏ合金、Ｆｅ－Ｃｒ合金等が挙げられる。
　三元素系合金としては、スーパーマロイ（登録商標）等のＦｅ－Ｎｉ－Ｍｏ合金、センダスト（登録商標）等のＦｅ－Ｓｉ－Ａｌ合金、Ｆｅ－Ｃｒ－Ｓｉ合金等が挙げられる。 Examples of these alloys include two-element alloys and three-element alloys.
Examples of the two-element alloys include Fe-Ni alloys such as Permalloy (registered trademark) that exhibit a soft magnetism with a coercive force of 70 Oersted (Oe) or less, Fe-Si alloys, Fe-Co alloys, Fe-Cr alloys, and the like. It is done.
Examples of the ternary alloy include Fe—Ni—Mo alloys such as Supermalloy (registered trademark), Fe—Si—Al alloys such as Sendust (registered trademark), and Fe—Cr—Si alloys.
　これらの合金の中でも、Ｆｅ－Ｎｉ合金としては、Ｎｉ７８質量％－Ｆｅ２２質量％の合金が、扁平状の磁性粉体、例えば、平均厚みが１０μｍ以下、平均長径が２０μｍ以下の平板状の磁性粉体が得られ易く、高透磁率とともに低磁気損失の磁性粉体を得られるので好ましい。 Among these alloys, as the Fe—Ni alloy, an alloy of Ni 78 mass% -Fe 22 mass% is a flat magnetic powder, for example, a flat magnetic powder having an average thickness of 10 μm or less and an average major axis of 20 μm or less. It is preferable because a body can be easily obtained and a magnetic powder with high magnetic permeability and low magnetic loss can be obtained.
　上記の合金に、その合金に含まれない金属元素で、その合金と性質が近い金属（合金に含まれている金属と周期律表で近接している金属）、例えば、アルミニウム（Ａｌ）、クロム（Ｃｒ）、マンガン（Ｍｎ）、コバルト（Ｃｏ）、銅（Ｃｕ）、亜鉛（Ｚｎ）、ニオブ（Ｎｂ）、モリブデン（Ｍｏ）、インジウム（Ｉｎ）、すず（Ｓｎ）等の群から１種または２種以上を適宜選択して添加してもよい。 A metal element that is not included in the alloy and has similar properties to the alloy (a metal that is close to the metal in the alloy in the periodic table), such as aluminum (Al), chromium (Cr), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), niobium (Nb), molybdenum (Mo), indium (In), tin (Sn), etc. Two or more kinds may be appropriately selected and added.
　上記の金属元素を合金に添加する場合には、この金属元素の含有率は、この金属元素と合金との合計質量に対して０．１質量％以上かつ９０質量％以下が好ましく、１質量％以上かつ１２質量％以下がより好ましく、１質量％以上かつ５質量％以下がさらに好ましい。
　ここで、上記の金属元素の含有率を上記の範囲に限定した理由は、金属元素の含有率が０．１質量％未満では、後述する球状の磁性粒子を扁平状にさせるための十分な塑性変形能を付与することができず、一方、含有率が９０質量％を超えると、金属元素自体の磁気モーメントが小さいことから、この扁平状の磁性粉体全体の飽和磁化が小さくなり、その結果、得られるμｒ’も小さくなるからである。 When the above metal element is added to the alloy, the content of the metal element is preferably 0.1% by mass or more and 90% by mass or less, preferably 1% by mass with respect to the total mass of the metal element and the alloy. It is more preferably 12% by mass or less, and further preferably 1% by mass or more and 5% by mass or less.
Here, the reason why the metal element content is limited to the above range is that, if the metal element content is less than 0.1% by mass, sufficient plasticity for flattening the spherical magnetic particles described later is used. On the other hand, when the content rate exceeds 90% by mass, the magnetic moment of the metal element itself is small, so that the saturation magnetization of the entire flat magnetic powder becomes small, and as a result. This is because the obtained μr ′ is also small.
　特に、アスペクト比が高くなり、結果として高いμｒ’の複合磁性体が得られ易い点で、柔らかい金属である、アルミニウム（Ａｌ）、亜鉛（Ｚｎ）、インジウム（Ｉｎ）、スズ（Ｓｎ）の群から選択される１種または２種以上の金属元素を１質量％以上かつ１２質量％以下、好ましくは１質量％以上かつ５質量％以下含む鉄－ニッケル合金を用いるのが好ましい。 Particularly, a group of soft metals such as aluminum (Al), zinc (Zn), indium (In), and tin (Sn) in that the aspect ratio is high and a high μr ′ composite magnetic body is easily obtained as a result. It is preferable to use an iron-nickel alloy containing one or more metal elements selected from 1 to 12% by mass, preferably 1 to 5% by mass.
　これらの中でも、ニッケル－鉄－亜鉛（Ｎｉ－Ｆｅ－Ｚｎ）合金は、Ｆｅ－Ｎｉ合金へのＺｎの添加により、後述する球状の磁性粒子の加工性が高くなるために、大きなアスペクト比を有する扁平状の磁性粉体が得られ易いので好ましい。合金の組成比としては、例えば、Ｎｉ７５質量％－Ｆｅ２０質量％－Ｚｎ５質量％の合金、Ｎｉ７６質量％－Ｆｅ２０質量％－Ｚｎ４質量％等を好適に用いることができる。 Among these, the nickel-iron-zinc (Ni—Fe—Zn) alloy has a large aspect ratio because the addition of Zn to the Fe—Ni alloy increases the workability of spherical magnetic particles described later. A flat magnetic powder is preferred because it is easy to obtain. As the composition ratio of the alloy, for example, an alloy of Ni 75% by mass—Fe 20% by mass—Zn 5% by mass, Ni 76% by mass—Fe 20% by mass—Zn 4% by mass, and the like can be preferably used.
　この磁性粉体は、絶縁性であることが好ましい。絶縁性の磁性粉体を用いることで、複合磁性体中にて磁性粉体同士が接触することにより導電パスが形成されるのを抑制することができ、その結果、複合磁性体の誘電損失を低減させることができる。この絶縁性の磁性粉体においては、少なくとも粒子の表面が絶縁性を有していればよい。 This magnetic powder is preferably insulative. By using the insulating magnetic powder, it is possible to suppress the formation of a conductive path due to the contact between the magnetic powders in the composite magnetic body. As a result, the dielectric loss of the composite magnetic body is reduced. Can be reduced. In this insulating magnetic powder, it is sufficient that at least the surface of the particles has an insulating property.
　磁性粉体を絶縁性にする方法としては、特に限定されないが、例えば、磁性粉体の表面に５ｎｍ程度の絶縁性の酸化被膜を形成する方法が挙げられる。
　通常、磁性粉体を大気中で取り扱うことにより、この磁性粉体の表面に自然に酸化被膜が形成されるが、自然に形成される酸化被膜では絶縁性が不十分であり、複合磁性体の誘電損失を低減することが難しい。そこで、複合磁性体の誘電損失を低減させるためには、５０℃以上かつ２００℃以下の温度にて、１時間～数時間程度加熱処理することにより、磁性粉体の表面に５ｎｍ程度の絶縁性の酸化被膜を形成することが好ましい。 The method for making the magnetic powder insulative is not particularly limited, and examples thereof include a method of forming an insulating oxide film of about 5 nm on the surface of the magnetic powder.
Normally, when the magnetic powder is handled in the air, an oxide film is naturally formed on the surface of the magnetic powder, but the oxide film formed naturally has insufficient insulation, It is difficult to reduce dielectric loss. Therefore, in order to reduce the dielectric loss of the composite magnetic material, the surface of the magnetic powder is insulated by about 5 nm by heat treatment at a temperature of 50 ° C. or more and 200 ° C. or less for about 1 hour to several hours. It is preferable to form an oxide film.
　また、磁性粉体の表面に、この磁性粉体と異なる組成の絶縁性被膜を形成してもよい。
このような組成としては、例えば、酸化ケイ素、リン酸塩等の無機物質、あるいは、樹脂、界面活性剤等の有機物質等が挙げられる。これらの絶縁性被膜は、酸化被膜（自然酸化や加熱酸化による酸化被膜を含む）を有する磁性粉体の表面に形成してもよく、酸化被膜を有しない磁性粉体の表面に形成してもよい。 Further, an insulating film having a composition different from that of the magnetic powder may be formed on the surface of the magnetic powder.
Examples of such a composition include inorganic substances such as silicon oxide and phosphate, or organic substances such as resins and surfactants. These insulating films may be formed on the surface of a magnetic powder having an oxide film (including an oxide film formed by natural oxidation or heat oxidation), or may be formed on the surface of a magnetic powder having no oxide film. Good.
　この磁性粉体の平均厚みは０．０１μｍ以上かつ１０μｍ以下が好ましく、より好ましくは０．１μｍ以上かつ１μｍ以下である。
　また、この磁性粉体の平均長径は０．０５μｍ以上かつ２０μｍ以下が好ましく、より好ましくは０．２μｍ以上かつ１０μｍ以下である。
　この磁性粉体の平均厚み及び平均長径は、複数個の磁性粉体それぞれの厚み及び長径、例えば、１００個以上の磁性粉体、好ましくは５００個の磁性粉体それぞれの厚み及び長径を測定し、厚み及び長径各々の平均値を算出することで求めることができる。 The average thickness of the magnetic powder is preferably 0.01 μm or more and 10 μm or less, more preferably 0.1 μm or more and 1 μm or less.
The average major axis of the magnetic powder is preferably 0.05 μm or more and 20 μm or less, more preferably 0.2 μm or more and 10 μm or less.
The average thickness and average major axis of the magnetic powder are determined by measuring the thickness and major axis of each of the plurality of magnetic powders, for example, the thickness and major axis of each of the 100 or more magnetic powders, preferably 500 magnetic powders. The average value of each of the thickness and the major axis can be calculated.
　磁性粉体の大きさが上記範囲よりも大きいと、この磁性粉体を用いた複合磁性体を非接触ＩＣカードと金属部材との間に配設した場合に、非接触ＩＣカードと金属部材との間の磁気シールドになると同時に、磁性粉体そのものも金属であることから、この磁性粉体の中を渦電流が流れて、この磁力線の信号エネルギーの一部が熱エネルギーに変化し、磁気信号の減衰が生じる場合があるので、好ましくない。
　また、平均厚みが０．０１μｍ未満であると、後述する製造上困難であり、取り扱いも難しくなるので好ましくなく、また、平均厚みが１０μｍを超えると、粒子同士の融着に起因する厚みのばらつきが生じ、ｔａｎδμ、ｔａｎδεが増加するので好ましくない。 When the size of the magnetic powder is larger than the above range, when the composite magnetic body using the magnetic powder is disposed between the non-contact IC card and the metal member, the non-contact IC card and the metal member Since the magnetic powder itself is also a metal at the same time, an eddy current flows through this magnetic powder, and part of the signal energy of this magnetic field line changes to thermal energy, and the magnetic signal This is not preferable because there is a case where the attenuation of the above occurs.
Further, if the average thickness is less than 0.01 μm, it will be difficult to manufacture as will be described later, and it will be difficult to handle, and if the average thickness exceeds 10 μm, it is not preferable. And tan δμ and tan δε increase, which is not preferable.
　ここで、磁性粉体の平均長径が０．０５μｍ未満では、磁性粉体自体の製造が難しく、複合磁性体を製造する際の取り扱いも難しく、その結果、配向が良好でありかつ複素透磁率の実部μｒ’が高い複合磁性体を得ることが難しくなるので好ましくない。
　一方、この磁性粉体の平均長径が２０μｍを超えると、絶縁材料中での粒子の分散が不安定になり易くなり、さらには、磁性粉体の間隙が小さくなり過ぎる等により、磁性粉体間の間隙に絶縁材料が進入し難くなり、その結果、気孔が生成され易くなり、所望のμｒ’が得られない虞があるので好ましくない。 Here, if the average major axis of the magnetic powder is less than 0.05 μm, it is difficult to manufacture the magnetic powder itself, and it is difficult to handle the composite magnetic body. As a result, the orientation is good and the complex permeability is low. This is not preferable because it is difficult to obtain a composite magnetic body having a high real part μr ′.
On the other hand, if the average major axis of the magnetic powder exceeds 20 μm, the dispersion of the particles in the insulating material tends to become unstable, and the gap between the magnetic powders becomes too small. As a result, it becomes difficult for the insulating material to enter the gap, and as a result, pores are easily generated, and the desired μr ′ may not be obtained.
　この磁性粉体の平均アスペクト比（長さ／厚み）は５以上であることが好ましく、より好ましくは７以上である。
　ここで、この磁性粉体の形状が、平均アスペクト比（長さ／厚み）が５以上の扁平状が好ましい理由は、次のとおりである。
　磁性粉体における反磁界の大きさは、粉体の形状に依存する。例えば、磁性粉体が球状の場合には、反磁界が等方的に存在するので、得られる透磁率も等方的となり、高周波領域で優れた磁気特性を得ることは困難である。一方、磁性粉体が扁平状の場合には、扁平状の一面に平行な方向の反磁界が、扁平状の垂直方向の反磁界に対して格段に小さくなり、したがって、得られるμｒ’が大きくなるので、好ましい。 The average aspect ratio (length / thickness) of the magnetic powder is preferably 5 or more, more preferably 7 or more.
Here, the reason why the shape of the magnetic powder is preferably a flat shape having an average aspect ratio (length / thickness) of 5 or more is as follows.
The magnitude of the demagnetizing field in the magnetic powder depends on the shape of the powder. For example, when the magnetic powder is spherical, since the demagnetizing field is isotropic, the magnetic permeability obtained is isotropic, and it is difficult to obtain excellent magnetic properties in the high frequency region. On the other hand, when the magnetic powder has a flat shape, the demagnetizing field in the direction parallel to the flat surface is much smaller than the flat demagnetizing field in the vertical direction, and thus the obtained μr ′ is large. Therefore, it is preferable.
　一方、平均アスペクト比が大きくなると、磁性粉体自体の機械的強度が低下する虞がある。そこで、磁性粉体が所望の機械的強度を確保するためには、平均アスペクト比は１５以下が好ましく、実用的には２０程度が上限となる。
　さらに、平均アスペクト比が２０を超えると、磁性粉体の形状が扁平すぎることで、磁性体同士の間が狭くなり、この間に絶縁性材料が進入し難い空間が形成され易くなり、その結果、複合磁性体中に気泡が生じ易くなり、この気泡の存在によりμｒ’が低下するので好ましくない。
　したがって、平均アスペクト比は５以上かつ２０以下であることが好ましく、７以上かつ１５以下であることがより好ましい。 On the other hand, when the average aspect ratio increases, the mechanical strength of the magnetic powder itself may be reduced. Therefore, in order to ensure the desired mechanical strength of the magnetic powder, the average aspect ratio is preferably 15 or less, and practically about 20 is the upper limit.
Furthermore, when the average aspect ratio exceeds 20, the shape of the magnetic powder is too flat, the space between the magnetic bodies becomes narrow, and a space in which the insulating material does not easily enter is easily formed between the magnetic bodies. Bubbles are likely to be generated in the composite magnetic material, and the presence of the bubbles lowers μr ′, which is not preferable.
Therefore, the average aspect ratio is preferably 5 or more and 20 or less, and more preferably 7 or more and 15 or less.
　この磁性粉体の平均アスペクト比（長径／厚み）も、上記の平均厚み及び平均長径と同様、複数個の磁性粉体それぞれの厚み及び長径、例えば、１００個以上の磁性粉体、好ましくは５００個の磁性粉体それぞれの厚み及び長径を測定し、厚み及び長径各々の平均値を算出することで求めることができる。 The average aspect ratio (major axis / thickness) of this magnetic powder is also the same as the above average thickness and average major axis, and the thickness and major axis of each of the plurality of magnetic powders, for example, 100 or more magnetic powders, preferably 500 It can be obtained by measuring the thickness and major axis of each of the magnetic powders and calculating the average value of the thickness and major axis.
　本実施形態の磁性粉体は、平均粒子径が１０ｎｍ以上かつ３μｍ以下の球状の磁性粒子に機械的応力を加えることにより、この球状の磁性粒子同士が接触し変形して融着することにより得られるものが好ましい。
　この過程を経ることにより、平均粒子径が１０ｎｍ以上かつ３μｍ以下の球状の磁性粒子は、平均厚みが０．０１μｍ以上かつ１０μｍ以下、平均長径が０．０５μｍ以上かつ２０μｍ以下、平均アスペクト比（長さ／厚み）が５以上の扁平状の磁性粉体となる。 The magnetic powder of the present embodiment is obtained by applying mechanical stress to spherical magnetic particles having an average particle diameter of 10 nm or more and 3 μm or less so that the spherical magnetic particles are brought into contact with each other and deformed and fused. Are preferred.
Through this process, spherical magnetic particles having an average particle diameter of 10 nm or more and 3 μm or less have an average thickness of 0.01 μm or more and 10 μm or less, an average major axis of 0.05 μm or more and 20 μm or less, an average aspect ratio (long (Thickness / thickness) is 5 or more flat magnetic powder.
　ここで、球状粒子の平均粒子径を３μｍ以下としたのは、平均粒子径を３μｍ以下とすることで球状粒子の表面が高活性となり、また、粒子同士の親和性も高くなり、その結果、粒子同士の変形及び融着が促進し、扁平状の磁性粉体が形成され易くなるからである。より好ましい球状粒子の平均粒子径は、１００ｎｍ以上かつ０．５μｍ以下である。 Here, the average particle diameter of the spherical particles is set to 3 μm or less, the surface of the spherical particles becomes highly active when the average particle diameter is set to 3 μm or less, and the affinity between the particles is also increased. This is because deformation and fusion between particles are promoted, and flat magnetic powder is easily formed. More preferably, the average particle diameter of the spherical particles is 100 nm or more and 0.5 μm or less.
「絶縁材料」
　本実施形態の絶縁材料としては、機械的強度が高く、吸湿性が低く、形状加工性に優れていることが好ましく、例えば、ポリアミド樹脂、ポリイミド樹脂、ポリアミドイミド樹脂、ポリエーテルイミド樹脂、ポリカーボネート樹脂、ポリアセタール樹脂、ポリブチレンテレフタレート樹脂、ポリベンゾオキサゾール樹脂、ポリフェニレン樹脂、ポリベンゾシクロブテン樹脂、ポリアリーレンエーテル樹脂、ポリシロキサン樹脂、エポキシ樹脂、ポリエステル樹脂、フッ素樹脂、ポリオレフィン樹脂、ポリシクロオレフィン樹脂、シアネート樹脂、ポリフェニレンエーテル樹脂、ポリフェニレンサルファイド樹脂、ポリアリレート樹脂、ポリエーテルエーテルケトン樹脂、ポリサルホン樹脂、ポリエーテルサルホン樹脂、ノルボルネン樹脂、ＡＢＳ樹脂、ポリスチレン樹脂等の熱硬化性樹脂あるいは熱可塑性樹脂が好適に用いられる。 "Insulating material"
As the insulating material of this embodiment, it is preferable that the mechanical strength is high, the hygroscopic property is low, and the shape workability is excellent. For example, polyamide resin, polyimide resin, polyamideimide resin, polyetherimide resin, polycarbonate resin , Polyacetal resin, polybutylene terephthalate resin, polybenzoxazole resin, polyphenylene resin, polybenzocyclobutene resin, polyarylene ether resin, polysiloxane resin, epoxy resin, polyester resin, fluorine resin, polyolefin resin, polycycloolefin resin, cyanate Resin, polyphenylene ether resin, polyphenylene sulfide resin, polyarylate resin, polyether ether ketone resin, polysulfone resin, polyether sulfone resin, norbornene resin, A S resin, thermosetting resin or thermoplastic resin such as polystyrene resin is preferably used.
　なかでも、熱硬化性樹脂としては、機械的強度及び形状加工性に優れているエポキシ樹脂が好ましく、また、熱可塑性樹脂としては、ポリスチレン樹脂、ポリフェニレン樹脂、ＡＢＳ樹脂が好ましい。これらの樹脂は、１種のみを単独で用いてもよく、２種以上を組み合わせて用いてもよい。 Among these, as the thermosetting resin, an epoxy resin excellent in mechanical strength and shape processability is preferable, and as the thermoplastic resin, a polystyrene resin, a polyphenylene resin, and an ABS resin are preferable. These resins may be used alone or in combination of two or more.
　また、上記の絶縁材料に熱可塑性エラストマーを添加してもよい。熱可塑性エラストマーを添加することにより、複合磁性体の機械的強度や形状加工性を向上させることができる。したがって、熱可塑性エラストマーが添加された複合磁性体は、靭性、柔軟性、変形性により優れたものとなる。 Further, a thermoplastic elastomer may be added to the above insulating material. By adding a thermoplastic elastomer, the mechanical strength and shape processability of the composite magnetic material can be improved. Therefore, the composite magnetic body to which the thermoplastic elastomer is added is excellent in toughness, flexibility and deformability.
　熱可塑性エラストマーとしては、スチレン系エラストマー、オレフィン系エラストマー、塩化ビニル系エラストマー、ウレタン系エラストマー、エステル系エラストマー、アミド系エラストマーの群から選択される１種または２種以上を用いることができる。
　熱可塑性エラストマーの添加量は、複合磁性体の用途により必要とされる耐熱性を勘案して、適宜調整して実施すればよい。 As the thermoplastic elastomer, one or more selected from the group of styrene elastomers, olefin elastomers, vinyl chloride elastomers, urethane elastomers, ester elastomers and amide elastomers can be used.
The amount of thermoplastic elastomer added may be adjusted as appropriate in consideration of the heat resistance required for the application of the composite magnetic material.
［複合磁性体の製造方法］
　本実施形態の複合磁性体の製造方法は、平均粒子径が３μｍ以下の球状の磁性粒子を界面活性剤を含む溶液中に分散してなるスラリー及び分散媒体を、密閉可能な容器内に、前記スラリー及び前記分散媒体の合計の体積量が前記容器内の体積と同じくなるように充填し、このスラリーを前記分散媒体と共に密閉状態にて機械的応力（機械的なせん断エネルギー）を加えながら撹拌し、前記球状の磁性粒子同士を変形及び融着させて扁平状の磁性粉体とする第１の工程と、前記扁平状の磁性粉体を、液状の樹脂中または樹脂を溶媒に溶解した溶液中に分散し混合して成形材料とする第２の工程と、前記成形材料を成形または基材上に塗布し、乾燥し、熱処理または焼成する第３の工程と、を備えている。 [Production Method of Composite Magnetic Material]
In the method for producing a composite magnetic body of the present embodiment, a slurry and a dispersion medium obtained by dispersing spherical magnetic particles having an average particle diameter of 3 μm or less in a solution containing a surfactant are placed in a sealable container. The slurry is filled so that the total volume of the slurry and the dispersion medium is the same as the volume in the container, and the slurry is stirred together with the dispersion medium while applying mechanical stress (mechanical shear energy) in a sealed state. A first step of deforming and fusing the spherical magnetic particles together to form a flat magnetic powder; and the flat magnetic powder in a liquid resin or a solution in which a resin is dissolved in a solvent. And a third step in which the molding material is molded or coated on a substrate, dried, heat-treated or fired.
　以下、各工程について詳細に説明する。
（第１の工程）
　まず、平均粒子径が１０ｎｍ以上かつ３μｍ以下の球状の磁性粒子を界面活性剤を含む溶液中に分散してスラリーとする。 Hereinafter, each step will be described in detail.
(First step)
First, spherical magnetic particles having an average particle diameter of 10 nm or more and 3 μm or less are dispersed in a solution containing a surfactant to obtain a slurry.
　磁性粒子の組成は、上記の磁性粉体の組成と全く同様である。
　球状の磁性粒子の作製方法は、特に限定されず、液相還元法、アトマイズ法等の公知の方法で合成したものを用いることができるが、特に、平均粒子径が３μｍ以下の球状粒子を合成することを考慮すると、液相還元法を用いることが好ましい。 The composition of the magnetic particles is exactly the same as the composition of the above magnetic powder.
The method for producing the spherical magnetic particles is not particularly limited, and those synthesized by a known method such as a liquid phase reduction method or an atomization method can be used. In particular, spherical particles having an average particle size of 3 μm or less are synthesized. In view of this, it is preferable to use a liquid phase reduction method.
　界面活性剤としては、磁性粒子の表面と相性の良い窒素、リン、イオウ等の元素を含有している界面活性剤が好ましく、例えば、窒素含有ブロックコポリマー、燐酸塩、ポリビニルピロリドン等が挙げられる。
　この界面活性剤を溶解させる溶媒としては、磁性粒子に含まれる金属元素の酸化を防止する必要があることから、有機溶媒が好ましく、特に、キシレン、トルエン、シクロペンタノン、シクロヘキサノン等の非極性有機溶媒が好ましい。 As the surfactant, a surfactant containing an element such as nitrogen, phosphorus or sulfur that is compatible with the surface of the magnetic particles is preferable, and examples thereof include a nitrogen-containing block copolymer, a phosphate, and polyvinylpyrrolidone.
As the solvent for dissolving the surfactant, an organic solvent is preferable because it is necessary to prevent oxidation of the metal element contained in the magnetic particles, and in particular, nonpolar organic materials such as xylene, toluene, cyclopentanone, and cyclohexanone. A solvent is preferred.
　次いで、このスラリー及び分散媒体を、密閉可能な容器内に、このスラリー及び分散媒体の合計の体積が容器内の体積と同じくなるように充填し、このスラリーを分散媒体と共に密閉状態にて撹拌し、球状の磁性粒子同士を変形及び融着させて扁平状の磁性粉体とする。 Next, the slurry and the dispersion medium are filled in a sealable container so that the total volume of the slurry and the dispersion medium is the same as the volume in the container, and the slurry is stirred together with the dispersion medium in a sealed state. Then, the spherical magnetic particles are deformed and fused to form a flat magnetic powder.
　分散媒体としては、球状の磁性粒子よりも硬度が高いことが必要であり、例えば、アルミニウム、鋼（スチール）、ステンレススチール、鉛等の金属球、アルミナ、ジルコニア、二酸化ケイ素、チタニア等の金属酸化物あるいは無機酸化物からなる球状焼結体、窒化ケイ素等の無機窒化物からなる球状焼結体、炭化ケイ素等の無機炭化物からなる球状焼結体、ソーダガラス、鉛ガラス、高比重ガラス等からなるビーズと称される球状粒子が挙げられ、中でも、比重６以上のジルコニア、鋼（スチール）、ステンレススチール等が効率の点から好ましい。 The dispersion medium must be harder than spherical magnetic particles, for example, metal spheres such as aluminum, steel (steel), stainless steel, and lead, and metal oxides such as alumina, zirconia, silicon dioxide, and titania. Spherical sintered body made of an inorganic oxide such as silicon nitride, spherical sintered body made of inorganic nitride such as silicon nitride, spherical sintered body made of inorganic carbide such as silicon carbide, soda glass, lead glass, high specific gravity glass, etc. In particular, zirconia, steel (steel), stainless steel and the like having a specific gravity of 6 or more are preferable from the viewpoint of efficiency.
　球状の磁性粒子への機械的応力の付加は、分散媒体の衝突の際に、球状磁性粒子が、分散媒体と分散媒体の間、または分散媒体と密閉容器の内壁との間に挟まれることで与えられる衝撃によって行われる。そのため、分散媒体同士あるいは分散媒体と容器の壁との衝突回数が増加するにつれて、球状の磁性粒子同士の変形及び融着性が向上する。
　このように、分散媒体の平均粒径が小さいほど、単位体積当たりに存在する個数が増加し、衝突回数も多くなり、変形及び融着性も向上するが、一方、分散媒体の平均粒径が小さすぎると、この分散媒体をスラリーから分離することが困難となる。したがって、分散媒体の平均粒径は、少なくとも０．０３ｍｍ以上、好ましくは０．０４ｍｍ以上であることが必要である。
　また、分散媒体の平均粒径が大き過ぎると、衝突回数が減少することから、球状の磁性粒子同士の変形及び融着性が低下する。したがって、分散媒体の平均粒径の上限値は３．０ｍｍである。 The mechanical stress is applied to the spherical magnetic particles because the spherical magnetic particles are sandwiched between the dispersion medium and the dispersion medium or between the dispersion medium and the inner wall of the closed container when the dispersion medium collides. It is done by the shock given. Therefore, as the number of collisions between the dispersion media or between the dispersion media and the container wall increases, the deformation and fusion properties between the spherical magnetic particles improve.
Thus, the smaller the average particle size of the dispersion medium, the more the number existing per unit volume, the greater the number of collisions, and the better the deformation and fusion properties. If it is too small, it will be difficult to separate the dispersion medium from the slurry. Therefore, the average particle size of the dispersion medium needs to be at least 0.03 mm or more, preferably 0.04 mm or more.
In addition, when the average particle size of the dispersion medium is too large, the number of collisions decreases, so that the deformation and fusion property between the spherical magnetic particles deteriorates. Therefore, the upper limit of the average particle diameter of the dispersion medium is 3.0 mm.
　密閉可能な容器としては、ディスク、スクリュー、羽根、ピン等の一軸回転体を高速回転することで、分散媒体をスラリーとともに高速回転する密閉容器が好ましい。
　この密閉容器は、単純な１軸回転方式であることから、大型化も容易であり、工業生産上も有利である。
　上記の密閉可能な容器に、スラリーを容器内に導入・導出するための流入口及び流出口を設け、スラリーを密閉容器内に循環するようにしてもかまわない。この場合、予め分散媒体を密閉容器内に収納しておき、球状の磁性粒子と界面活性剤と溶媒とを混合したスラリーを流入口から投入して容器内に空間がないように充填し、流出口から排出されるスラリーを再度密閉容器内へ投入するようにすればよい。
　この場合、スラリーが容器から排出されて、再度密閉容器内へ投入される間は、磁性粒子に機械的な応力がかからず、扁平状になりかけた粒子と球状粒子がよく混合されるために、微細で均一な扁平粒子となりやすい。例えば、長径が２μｍ以下でかつアスペクト比が５以上の粒子ができるので、ｔａｎδμを低減する要因となる。 As the container that can be sealed, a sealed container that rotates a uniaxial rotating body such as a disk, screw, blade, or pin at a high speed by rotating the dispersion medium together with the slurry is preferable.
Since this hermetic container is a simple uniaxial rotation system, it is easy to increase the size and is advantageous for industrial production.
The above sealable container may be provided with an inlet and an outlet for introducing and discharging the slurry into and from the container, and the slurry may be circulated in the sealed container. In this case, the dispersion medium is previously stored in a sealed container, and a slurry in which spherical magnetic particles, a surfactant, and a solvent are mixed is introduced from the inlet and filled so that there is no space in the container. The slurry discharged from the outlet may be charged again into the sealed container.
In this case, while the slurry is discharged from the container and put into the sealed container again, the magnetic particles are not subjected to mechanical stress, and the flattened particles and spherical particles are well mixed. In addition, it tends to be fine and uniform flat particles. For example, particles having a major axis of 2 μm or less and an aspect ratio of 5 or more are produced, which is a factor for reducing tan δμ.
　ここでは、スラリー及び分散媒体の上記の密閉容器内への充填量を、密閉容器内の体積と同一とする。換言すれば、スラリー及び分散媒体を、密閉容器内に隙間なく充填する。
　ここで、スラリー及び分散媒体を、密閉容器内に隙間なく充填する理由は、次のとおりである。 Here, the filling amount of the slurry and the dispersion medium into the above-mentioned closed container is the same as the volume in the closed container. In other words, the slurry and the dispersion medium are filled in the sealed container without gaps.
Here, the reason why the slurry and the dispersion medium are filled in the sealed container without any gap is as follows.
　図１は、上部が開放された開放容器１に投入された球状の磁性粒子２を含むスラリー３及び分散媒体４を、一軸回転体５により高速回転することで高速撹拌する様を示す図である。
　この図では、一軸回転体５が高速で回転すると、スラリー３及び分散媒体４の液面は、遠心力により中心軸近傍が低く、周縁部が高いすり鉢状となる。
　一軸回転体５により球状の磁性粒子２を含むスラリー３及び分散媒体４に加えられた機械的応力は、すり鉢状の空間に逃げていくので、開放容器１内全体で分散媒体４を介して球状の磁性粒子２に伝搬される機械的応力は不均一なものとなり、得られた扁平状の磁性粉体の厚みがばらつく要因となる。
　また、すり鉢状の空間の底部近傍（中心軸近傍）で扁平状となった磁性粉体は、分散媒体と共にすり鉢状の空間に放出されて不規則な衝撃を受けることとなり、割れや欠け等が生じる虞がある。このような磁性粉体の厚みのばらつきや割れや欠けは、ｔａｎδμ、ｔａｎδεが増加する要因となっている。 FIG. 1 is a diagram showing a state in which a slurry 3 and a dispersion medium 4 containing spherical magnetic particles 2 charged in an open container 1 having an open top are stirred at high speed by rotating at high speed with a uniaxial rotating body 5. .
In this figure, when the uniaxial rotating body 5 rotates at a high speed, the liquid surfaces of the slurry 3 and the dispersion medium 4 have a mortar shape with a low vicinity of the central axis and a high peripheral edge due to centrifugal force.
The mechanical stress applied to the slurry 3 containing the spherical magnetic particles 2 and the dispersion medium 4 by the uniaxial rotating body 5 escapes into the mortar-like space, so that the entire inside of the open container 1 is spherical via the dispersion medium 4. The mechanical stress propagated to the magnetic particles 2 becomes non-uniform, and the thickness of the obtained flat magnetic powder varies.
In addition, the magnetic powder that is flat near the bottom of the mortar-shaped space (near the central axis) is discharged into the mortar-shaped space together with the dispersion medium and is subject to irregular impacts. May occur. Such variations in thickness, cracks, and chipping of the magnetic powder cause tan δμ and tan δε to increase.
　図２は、密閉容器１１に投入された球状の磁性粒子２を含むスラリー３及び分散媒体４を、一軸回転体５により高速回転することで高速撹拌する様を示す図である。
　この図では、一軸回転体５が高速で回転しても、密閉容器１１内が球状の磁性粒子２を含むスラリー３及び分散媒体４により満たされているので、開放容器１に見られるようなすり鉢状の空間が生じる虞は無い。したがって、一軸回転体５により球状の磁性粒子２を含むスラリー３及び分散媒体４に加えられた機械的応力は、密閉容器１１内全体で分散媒体４を介して球状の磁性粒子２に均一に伝搬され、得られた扁平状の磁性粉体の厚みがばらつく虞は無い。また、扁平状となった磁性粉体は、不規則な衝撃を受けることもなく、割れや欠け等が生じる虞もない。 FIG. 2 is a diagram showing that the slurry 3 and the dispersion medium 4 containing the spherical magnetic particles 2 charged in the sealed container 11 are stirred at a high speed by being rotated at a high speed by the uniaxial rotating body 5.
In this figure, even if the uniaxial rotating body 5 rotates at a high speed, the sealed container 11 is filled with the slurry 3 and the dispersion medium 4 containing the spherical magnetic particles 2, so that the mortar as seen in the open container 1 is used. There is no risk of creating a space. Therefore, the mechanical stress applied to the slurry 3 containing the spherical magnetic particles 2 and the dispersion medium 4 by the uniaxial rotating body 5 is uniformly propagated to the spherical magnetic particles 2 through the dispersion medium 4 in the entire sealed container 11. Thus, there is no possibility that the thickness of the obtained flat magnetic powder varies. Further, the flat magnetic powder is not subjected to irregular impacts, and there is no possibility of cracking or chipping.
　一軸回転体５の回転数は、密閉容器１１の大きさにより決定される。例えば、内径が１２０ｍｍの密閉容器１１の場合、球状の磁性粒子２を含むスラリー３及び分散媒体４の一軸回転体５の径方向の外周端５ａ付近の流速が５ｍ／秒以上となるように、一軸回転体５の回転数を設定することが好ましく、この外周端５ａ付近の流速が８ｍ／秒以上となるように、一軸回転体５の回転数を設定することがより好ましい。
　一方、外周端５ａ付近の流速が１５ｍ／ｓを超えると、エネルギーが大きすぎるために平板状になった粒子を破壊してしまう虞があるので、外周端５ａ付近の流速は１５ｍ／ｓ以下であることが好ましい。 The rotational speed of the uniaxial rotating body 5 is determined by the size of the sealed container 11. For example, in the case of the sealed container 11 having an inner diameter of 120 mm, the flow velocity in the vicinity of the outer peripheral end 5a in the radial direction of the uniaxial rotating body 5 of the slurry 3 and the dispersion medium 4 including the spherical magnetic particles 2 is 5 m / second or more It is preferable to set the rotational speed of the uniaxial rotating body 5, and it is more preferable to set the rotational speed of the uniaxial rotating body 5 so that the flow velocity in the vicinity of the outer peripheral end 5a is 8 m / second or more.
On the other hand, if the flow velocity in the vicinity of the outer peripheral edge 5a exceeds 15 m / s, there is a risk of destroying the flattened particles because the energy is too large, so the flow velocity in the vicinity of the outer peripheral edge 5a is 15 m / s or less. Preferably there is.
　密閉容器１１の内容積が小さいと、得られた扁平状の磁性粉体に球状の磁性粒子２が残留する虞がある。残留した球状の磁性粒子２は、球状の磁性粒子２同士の接触、または球状の磁性粒子２と扁平状の磁性粉体との接触により、ｔａｎδμ、ｔａｎδεを増加させたり、扁平状の磁性粉体の配向を阻害したりする虞がある。したがって、扁平状の磁性粉体は、磁性粉体全体量の９０質量％以上が好ましく、より好ましくは９５質量％以上、さらに好ましくは９９質量％以上であり、球状の磁性粒子については、実質的に含まないことが望ましい。 If the internal volume of the sealed container 11 is small, the spherical magnetic particles 2 may remain in the obtained flat magnetic powder. The remaining spherical magnetic particles 2 increase tan δμ and tan δε by contact between the spherical magnetic particles 2 or contact between the spherical magnetic particles 2 and the flat magnetic powder. There is a risk of disturbing the orientation of the film. Therefore, the flat magnetic powder is preferably 90% by mass or more of the total amount of the magnetic powder, more preferably 95% by mass or more, and further preferably 99% by mass or more. It is desirable not to include.
　ここで、密閉容器１１の内容積が小さい場合に球状の磁性粒子２が残留する理由は、密閉容器１１の角や回転体５と密閉容器１１との接合部といった機械的応力が十分に伝わらないデッドスペースが相対的に大きくなるからと考えられる。そこで、密閉容器１１の内容積を大きくすると、相対的にデッドスペースが小さくなり、よって、球状粒子２に機械的応力が十分に伝わり、球状の磁性粒子同士の変形及び融着性が向上し、その結果、球状の磁性粒子２の残留が少なくなり、実質的に球状の磁性粒子２がなくなる。
　このように、実質的に球状の磁性粒子２が残留しなくなる密閉容器１１の体積は、１Ｌ以上が好ましく、より好ましくは５Ｌ以上である。
　以上により、球状の磁性粒子同士は、一軸回転体５により加えられた機械的応力により変形及び融着し、扁平状の磁性粉体となる。 Here, the reason why the spherical magnetic particles 2 remain when the inner volume of the sealed container 11 is small is that the mechanical stress such as the corner of the sealed container 11 and the joint between the rotating body 5 and the sealed container 11 is not sufficiently transmitted. This is probably because the dead space becomes relatively large. Therefore, when the internal volume of the sealed container 11 is increased, the dead space is relatively reduced, and therefore, the mechanical stress is sufficiently transmitted to the spherical particles 2, and the deformation and fusion property between the spherical magnetic particles is improved. As a result, the residual spherical magnetic particles 2 are reduced, and the substantially spherical magnetic particles 2 are eliminated.
Thus, the volume of the sealed container 11 in which substantially spherical magnetic particles 2 do not remain is preferably 1 L or more, more preferably 5 L or more.
As described above, the spherical magnetic particles are deformed and fused by the mechanical stress applied by the uniaxial rotating body 5 to form a flat magnetic powder.
　次いで、この扁平状の磁性粉体を分散媒体及び溶媒から分離する。
　分離方法は、扁平状の磁性粉体を作製した後のスラリーから溶媒を除去することができれば特に限定されず、加熱乾燥、真空乾燥、フリーズドライ等が挙げられるが、乾燥効率の点で真空乾燥が好ましい。また、乾燥効率を高めるために、乾燥工程の前に、固液分離等の手法によりある程度の溶媒を除去してもよい。固液分離の方法としては、フィルタープレス、吸引ろ過等のろ過操作、あるいはデカンター、遠心分離機による遠心分離操作等、通常の方法を用いればよい。 Next, the flat magnetic powder is separated from the dispersion medium and the solvent.
The separation method is not particularly limited as long as the solvent can be removed from the slurry after producing the flat magnetic powder, and examples thereof include heat drying, vacuum drying, freeze drying, etc., but vacuum drying in terms of drying efficiency. Is preferred. In order to increase the drying efficiency, some solvent may be removed by a method such as solid-liquid separation before the drying step. As a method of solid-liquid separation, a normal method such as a filtration operation such as a filter press or suction filtration, or a centrifugal operation using a decanter or a centrifuge may be used.
　また、この溶媒が除去された磁性粉体を、５０℃以上かつ２００℃以下にて、１時間以上かつ数時間以下、加熱処理してもよい。この加熱処理により、扁平状の磁性粉体の表面に酸化被膜を形成することができ、絶縁性の磁性粉体を得ることができる。 In addition, the magnetic powder from which the solvent has been removed may be heat-treated at 50 ° C. or more and 200 ° C. or less for 1 hour or more and several hours or less. By this heat treatment, an oxide film can be formed on the surface of the flat magnetic powder, and an insulating magnetic powder can be obtained.
（第２の工程）
　上述の扁平状の磁性粉体を、液状の樹脂中または樹脂を溶媒に溶解した溶液中に分散し混合してスラリーとし、このスラリーを成形材料とする。
　ここで、樹脂としては、液状の樹脂が好ましく、例えば、ポリアミド樹脂、ポリイミド樹脂、ポリアミドイミド樹脂、ポリエーテルイミド樹脂、ポリカーボネート樹脂、ポリアセタール樹脂、ポリブチレンテレフタレート樹脂、ポリベンゾオキサゾール樹脂、ポリフェニレン樹脂、ポリベンゾシクロブテン樹脂、ポリアリーレンエーテル樹脂、ポリシロキサン樹脂、エポキシ樹脂、ポリエステル樹脂、フッ素樹脂、ポリオレフィン樹脂、ポリシクロオレフィン樹脂、シアネート樹脂、ポリフェニレンエーテル樹脂、ポリフェニレンサルファイド樹脂、ポリアリレート樹脂、ポリエーテルエーテルケトン樹脂、ポリサルホン樹脂、ポリエーテルサルホン樹脂、ノルボルネン樹脂、ＡＢＳ樹脂、ポリスチレン樹脂等の熱硬化性樹脂あるいは熱可塑性樹脂が好適に用いられる。 (Second step)
The above-mentioned flat magnetic powder is dispersed and mixed in a liquid resin or a solution obtained by dissolving a resin in a solvent to form a slurry, and this slurry is used as a molding material.
Here, the resin is preferably a liquid resin, for example, polyamide resin, polyimide resin, polyamideimide resin, polyetherimide resin, polycarbonate resin, polyacetal resin, polybutylene terephthalate resin, polybenzoxazole resin, polyphenylene resin, polyphenylene resin, Benzocyclobutene resin, polyarylene ether resin, polysiloxane resin, epoxy resin, polyester resin, fluorine resin, polyolefin resin, polycycloolefin resin, cyanate resin, polyphenylene ether resin, polyphenylene sulfide resin, polyarylate resin, polyether ether ketone Thermosetting resin or thermoplastic such as resin, polysulfone resin, polyethersulfone resin, norbornene resin, ABS resin, polystyrene resin Resin is preferably used.
　絶縁材料として熱硬化性樹脂を用いる場合、硬化剤の種類や添加量については、使用する熱硬化性樹脂の種類や量に応じて適宜調整すればよい。
　硬化剤としては、上記の熱硬化性樹脂としてエポキシ樹脂を用いる場合、エポキシ基同士の縮合反応を促進させて、複合磁性体の成形時における硬化不良による気孔の発生を防止する点で第３アミンが好ましい。 When a thermosetting resin is used as the insulating material, the type and amount of the curing agent may be appropriately adjusted according to the type and amount of the thermosetting resin to be used.
As the curing agent, when an epoxy resin is used as the thermosetting resin, a tertiary amine is used in that the condensation reaction between the epoxy groups is promoted to prevent generation of pores due to poor curing at the time of molding the composite magnetic body. Is preferred.
　第３アミンとしては、例えば、１－イソブチル－２－メチルイミダゾール、１－ベンジル－２－メチルイミダゾール、１－シアノエチル－２－メチルイミダゾール、１－シアノエチル－２－エチル－４－メチルイミダゾール等が挙げられる。
　硬化剤の添加量としては、官能基の縮合反応を促進させる点を考慮すると、熱硬化性樹脂と第３アミンとの合計の質量に対して０．５質量％以上かつ３質量％以下、添加させればよい。
　絶縁材料として熱可塑性樹脂を用いる場合、硬化剤は不要である。 Examples of the tertiary amine include 1-isobutyl-2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, and the like. It is done.
The amount of the curing agent added is 0.5 mass% or more and 3 mass% or less based on the total mass of the thermosetting resin and the tertiary amine in consideration of promoting the condensation reaction of the functional group. You can do it.
When a thermoplastic resin is used as the insulating material, no curing agent is required.
　また、溶媒としては、上記の樹脂を溶解させることができるものであればよく、特に限定されないが、例えば、メタノール、エタノール、２－プロパノール、ブタノール、オクタノール等のアルコール類、酢酸エチル、酢酸ブチル、乳酸エチル、プロピレングリコールモノメチルエーテルアセテート、プロピレングリコールモノエチルエーテルアセテート、γ－ブチロラクトン等のエステル類、ジエチルエーテル、エチレングリコールモノメチルエーテル（メチルセロソルブ）、エチレングリコールモノエチルエーテル（エチルセロソルブ）、エチレングリコールモノブチルエーテル（ブチルセロソルブ）、ジエチレングリコールモノメチルエーテル、ジエチレングリコールモノエチルエーテル等のエーテル類、アセトン、メチルエチルケトン、メチルイソブチルケトン、アセチルアセトン、シクロヘキサノン等のケトン類、ベンゼン、トルエン、キシレン、エチルベンゼン等の芳香族炭化水素、ジメチルホルムアミド、Ｎ，Ｎ－ジメチルアセトアセトアミド、Ｎ－メチルピロリドン等のアミド類が好適に用いられ、これらの溶媒は、１種のみ単独で用いてもよく、２種以上を混合して用いてもよい。 Further, the solvent is not particularly limited as long as it can dissolve the above-mentioned resin. For example, alcohols such as methanol, ethanol, 2-propanol, butanol, octanol, ethyl acetate, butyl acetate, Esters such as ethyl lactate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, γ-butyrolactone, diethyl ether, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosolve), ethylene glycol monobutyl ether (Butyl cellosolve), ethers such as diethylene glycol monomethyl ether and diethylene glycol monoethyl ether, acetone, methyl ethyl ketone Preferred are ketones such as ethylene, methyl isobutyl ketone, acetylacetone and cyclohexanone, aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene, and amides such as dimethylformamide, N, N-dimethylacetoacetamide and N-methylpyrrolidone. These solvents may be used alone or in combination of two or more.
　得られたスラリーの粘度は０．１Ｐａ・ｓ以上かつ１０６Ｐａ・ｓ以下であることが好ましく、より好ましくは０．３Ｐａ・ｓ以上かつ１０４Ｐａ・ｓ以下である。
　ここで、粘度が０．１Ｐａ・ｓ未満の場合には、流動性が大きくなりすぎて乾燥工程での生産性が悪くなり、一方、粘度が１０６Ｐａ・ｓを超えると、粘性が高すぎて磁性粉体の配向が起こり難くなり、その結果、複合磁性体中における磁性粉体の配向性が低下してしまうので、好ましくない。 The viscosity of the obtained slurry is preferably 0.1 Pa · s or more and 10 6 Pa · s or less, more preferably 0.3 Pa · s or more and 10 4 Pa · s or less.
Here, when the viscosity is less than 0.1 Pa · s, the fluidity becomes too high and the productivity in the drying process is deteriorated. On the other hand, when the viscosity exceeds 10 6 Pa · s, the viscosity is too high. As a result, the orientation of the magnetic powder becomes difficult to occur, and as a result, the orientation of the magnetic powder in the composite magnetic material is lowered, which is not preferable.
　分散混合方法としては、特に制限はないが、遊星ミル、機械的応力を加えることができるサンドミル、ボールミル等の攪拌装置を用いることが好ましい。 The dispersion mixing method is not particularly limited, but it is preferable to use an agitator such as a planetary mill, a sand mill capable of applying mechanical stress, or a ball mill.
（第３の工程）
　上記の成形材料を成形または基材上に塗布し、乾燥し、熱処理または焼成する。
　成形方法としては、公知の成形方法、例えば、プレス法、ドクターブレード法、射出成形法等が好適である。この成形方法を用いて任意の形状のシート状またはフィルム状に成形することにより、ドライフィルムを作製することができる。
　複合磁性体が積層体の場合には、ドクターブレード法によりシート状またはフィルム状に成形することが望ましい。
　上記の成形材料は、粘度調整を行う必要がある場合には、溶媒を揮発させて濃縮後に成形を行う。必要があれば、成形材料を基材上に塗布した後、乾燥前に磁場の配向により扁平状の磁性粉体をシートまたはフィルムと平行な方向に配向する配向処理を行えばよい。
　熱処理または焼成の条件としては、還元性雰囲気中または真空中にて、熱処理またはホットプレスが好適である。これにより、本実施形態の複合磁性体が得られる。 (Third step)
The above molding material is molded or coated on a substrate, dried, heat-treated or fired.
As the molding method, a known molding method, for example, a press method, a doctor blade method, an injection molding method or the like is suitable. A dry film can be produced by forming a sheet or film of any shape using this forming method.
When the composite magnetic body is a laminate, it is preferably formed into a sheet or film by the doctor blade method.
When it is necessary to adjust the viscosity, the molding material is molded after the solvent is volatilized and concentrated. If necessary, after applying the molding material on the base material, an orientation treatment for orienting the flat magnetic powder in a direction parallel to the sheet or film by orientation of the magnetic field may be performed before drying.
As the heat treatment or firing conditions, heat treatment or hot pressing is preferable in a reducing atmosphere or in vacuum. Thereby, the composite magnetic body of this embodiment is obtained.
　上記の乾燥工程で得られた成形体の気孔率をさらに減少させたい場合には、上記の乾燥工程後に、成形体をプレスする工程を施すことが好ましい。プレス装置は公知のものを適宜用いればよい。
　また、プレス装置で成形体に圧力を加える際に、絶縁材料として樹脂を用いる場合には、効果的に気孔を減少させるために樹脂の軟化温度以上かつ硬化開始温度以下の温度範囲で圧力を加えることが好ましい。特に、熱可塑性樹脂を使用した場合には、樹脂の軟化温度以上の温度で圧力を加えて、樹脂同士を融着させる必要がある。
　プレス時の圧力は、成形材料の種類に応じて適宜調整すればよいが、５ＭＰａ～２０ＭＰａ程度の圧力を加えるのが好ましい。 When it is desired to further reduce the porosity of the molded body obtained in the drying step, it is preferable to perform a step of pressing the molded body after the drying step. A known press apparatus may be used as appropriate.
In addition, when using a resin as an insulating material when applying pressure to the molded body with a press device, in order to effectively reduce pores, apply pressure in a temperature range above the softening temperature of the resin and below the curing start temperature. It is preferable. In particular, when a thermoplastic resin is used, it is necessary to apply pressure at a temperature equal to or higher than the softening temperature of the resin to fuse the resins together.
The pressure during pressing may be appropriately adjusted according to the type of molding material, but it is preferable to apply a pressure of about 5 MPa to 20 MPa.
　扁平状の磁性粉体と熱硬化性樹脂あるいは熱可塑性樹脂とを加熱混錬により混合分散したものを成形することによっても、本実施形態の複合磁性体が得られる。
　加熱混練方法としては、公知の方法、例えば、加圧ニーダー、２軸式ニーダー、ブラストミル等で混合分散した混練物を作製することができる。この混練物の成形方法としては、公知の方法、例えば、加熱プレス成形、押出成形、射出成形等で成形体を作製することができる。これらの方法の中でも、扁平状の磁性粉体を樹脂中に配向させるためには、平面状に引き伸ばす加熱プレス成形が好ましい。引き伸ばす際の粘度調整のために、可塑剤の添加、扁平状の磁性粉体の表面処理を行うことも好ましい。必要があれば、加熱して流動性を維持した状態で、磁場の配向により扁平状の磁性粉体を配向する処理を行うことが好ましい。 The composite magnetic body of this embodiment can also be obtained by molding a flat magnetic powder and a thermosetting resin or thermoplastic resin mixed and dispersed by heat kneading.
As a heat-kneading method, a kneaded material mixed and dispersed by a known method such as a pressure kneader, a biaxial kneader, or a blast mill can be prepared. As a molding method of the kneaded product, a molded body can be produced by a known method such as hot press molding, extrusion molding, injection molding or the like. Among these methods, in order to orient the flat magnetic powder in the resin, hot press molding that is stretched flat is preferable. In order to adjust the viscosity at the time of stretching, it is also preferable to add a plasticizer and perform surface treatment of the flat magnetic powder. If necessary, it is preferable to perform a treatment for orienting the flat magnetic powder by the orientation of the magnetic field in a state where the fluidity is maintained by heating.
　本実施形態の複合磁性体の製造方法によれば、平均粒子径が３μｍ以下の球状の磁性粒子を界面活性剤を含む溶液中に分散してなるスラリー及び分散媒体を、密閉可能な容器内に、このスラリー及び分散媒体の合計の体積量が、この容器内の体積と同じくなるように充填し、このスラリーを分散媒体と共に密閉状態にて機械的応力（機械的なせん断エネルギー）を加えながら撹拌し、球状の磁性粒子同士を変形及び融着させて扁平状の磁性粉体とする第１の工程と、この扁平状の磁性粉体を、液状の樹脂中または樹脂を溶媒に溶解した溶液中に分散し混合して成形材料とする第２の工程と、この成形材料を成形または基材上に塗布し、乾燥し、熱処理または焼成する第３の工程と、を備えている。そのため、（１）１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’が１よりも大きく、複素透磁率の損失正接ｔａｎδμが０．０２以下、複素誘電率の実部εｒ’が５０以下、複素誘電率の損失正接ｔａｎδεが０．２以下の扁平状の複合磁性体、または、（２）１０ＭＨｚから２０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’が１よりも大きく、複素透磁率の損失正接ｔａｎδμが０．０１以下、複素誘電率の実部εｒ’が５０以下、複素誘電率の損失正接ｔａｎδεが０．２以下の扁平状の複合磁性体、を容易に作製することができる。 According to the method for producing a composite magnetic body of this embodiment, a slurry and a dispersion medium obtained by dispersing spherical magnetic particles having an average particle diameter of 3 μm or less in a solution containing a surfactant are placed in a sealable container. The slurry and the dispersion medium are filled so that the total volume is the same as the volume in the container, and the slurry is stirred together with the dispersion medium while applying mechanical stress (mechanical shear energy) in a sealed state. Then, the first step of deforming and fusing the spherical magnetic particles to form a flat magnetic powder, and the flat magnetic powder in a liquid resin or a solution obtained by dissolving the resin in a solvent. And a third step in which the molding material is molded or applied onto a substrate, dried, heat-treated or fired. Therefore, (1) the real part μr ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is larger than 1, the loss tangent tan δμ of the complex permeability is 0.02 or less, and the real part εr ′ of the complex permittivity is 50. Hereinafter, the complex magnetic material having a complex dielectric constant loss tangent tan δε of 0.2 or less, or (2) the real part μr ′ of the complex permeability in the frequency band from 10 MHz to 20 MHz is larger than 1, and the complex A flat composite magnetic body having a permeability loss tangent tan δμ of 0.01 or less, a complex dielectric constant real part εr ′ of 50 or less, and a complex dielectric loss tangent tan δε of 0.2 or less is easily produced. Can do.
［アンテナ］
　本実施形態のアンテナは、上記の複合磁性体を装荷し、かつ１０ＭＨｚから７０ＭＨｚまでの周波数帯域の電磁波を、送信、受信または送受信するアンテナである。
　このアンテナとしては、非接触ＩＣカードに用いられるアンテナであればよく、特に限定されず、例えばループ状のアンテナ等が挙げられる。
　このアンテナに上記の複合磁性体を装荷させる方法としては、特に制限されず、公知の方法で装荷させればよい。
　ここで、「装荷」とは、電磁的な相互作用により波長短縮等の効果が得られるようにするために、アンテナ導体に複合磁性体を接触あるいは近づけることである。 [antenna]
The antenna of this embodiment is an antenna that loads the above-described composite magnetic material and transmits, receives, or transmits / receives electromagnetic waves in a frequency band from 10 MHz to 70 MHz.
The antenna is not particularly limited as long as it is an antenna used for a non-contact IC card, and examples thereof include a loop antenna.
The method for loading the antenna with the composite magnetic material is not particularly limited, and may be loaded by a known method.
Here, “loading” is to bring the composite magnetic body into contact with or close to the antenna conductor in order to obtain an effect such as wavelength reduction by electromagnetic interaction.
　このアンテナでは、本実施形態の１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’が１よりも大きく、複素透磁率の損失正接ｔａｎδμが０．０２以下、複素誘電率の実部εｒ’が５０以下、複素誘電率の損失正接ｔａｎδεが０．２以下の扁平状の複合磁性体を装荷したので、この周波数帯域におけるアンテナ効率が高くなる。 In this antenna, the real part μr ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz of this embodiment is larger than 1, the loss tangent tan δμ of the complex permeability is 0.02 or less, and the real part εr of the complex permittivity Since a flat composite magnetic material having 'is 50 or less and the loss tangent tan δε of the complex dielectric constant is 0.2 or less is loaded, the antenna efficiency in this frequency band is increased.
［非接触ＩＣカード］
　本実施形態の非接触ＩＣカードは、上記の複合磁性体を備えている。
　上記の複合磁性体は、公知の形態及び方法により非接触ＩＣカードに実装させればよい。この非接触ＩＣカードの構造としては、例えば、裏面シート、基体シート、上記複合磁性体、及び表面シートが順次積層され、熱圧着または接着剤等によって相互に固着させた構造があげられる。 [Non-contact IC card]
The non-contact IC card of this embodiment includes the above composite magnetic body.
What is necessary is just to mount said composite magnetic body on a non-contact IC card by a well-known form and method. Examples of the structure of the non-contact IC card include a structure in which a back sheet, a base sheet, the composite magnetic body, and a top sheet are sequentially laminated and fixed to each other by thermocompression bonding or an adhesive.
　裏面シート及び表面シートは特に限定されないが、０．１ｍｍ～０．２ｍｍ程度の厚みの樹脂製の化粧用外装シート等を用いることができる。
　基体シートは、ループアンテナ等のＩＣカードに用いられるアンテナであって、かつそのアンテナ端子にＩＣチップが接続されたアンテナを備えたシートであれば特に限定されない。例えば、樹脂から構成されたシートにＩＣチップが接続されたループアンテナが配設された０．２ｍｍ～０．４ｍｍ程度の厚さのシートを用いることができる。 The back sheet and the top sheet are not particularly limited, and a resin cosmetic exterior sheet having a thickness of about 0.1 mm to 0.2 mm can be used.
The base sheet is not particularly limited as long as it is an antenna used for an IC card such as a loop antenna and includes an antenna having an IC chip connected to its antenna terminal. For example, a sheet having a thickness of about 0.2 mm to 0.4 mm in which a loop antenna in which an IC chip is connected to a sheet made of resin is disposed can be used.
　このように、ＩＣカード中に上記複合磁性体を設けることにより、表面シート側に金属部材が存在しても、電磁波のエネルギーが金属部材により吸収されることなく、磁力線の信号エネルギーの減衰を抑制することができる。その結果、非接触ＩＣカードとリーダーまたはリーダー／ライターとの通信距離を長くとることができる。 In this way, by providing the composite magnetic body in the IC card, even if a metal member exists on the surface sheet side, the energy of electromagnetic waves is not absorbed by the metal member, and the attenuation of the signal energy of the magnetic field lines is suppressed. can do. As a result, the communication distance between the non-contact IC card and the reader or reader / writer can be increased.
［通信装置］
　本実施形態の通信装置は、上記の複合磁性体を備えている。
　通信装置は、ＩＣカードを内蔵させて使用できるものであれば特に限定されず、例えば、携帯電話機、携帯用情報端末、多機能携帯用情報端末等の情報端末機器等が挙げられる。上記の複合磁性体を通信装置に配設させる方法は特に限定されず、公知の方法により配設させればよい。例えば、アンテナを有するＩＣカードと金属部材との間に上記複合磁性体を設けた構造が挙げられる。また、上記非接触ＩＣカードの表面シートが金属部材と対向するように配設させることにより、ＩＣカードの基体シートに設けられたアンテナと金属部材の間に複合磁性体を設けた構造が挙げられる。 [Communication device]
The communication device of this embodiment includes the above composite magnetic body.
The communication device is not particularly limited as long as it can be used with a built-in IC card, and examples thereof include information terminal devices such as a mobile phone, a portable information terminal, and a multifunctional portable information terminal. The method of disposing the above composite magnetic body in the communication device is not particularly limited, and may be disposed by a known method. For example, the structure which provided the said composite magnetic body between the IC card which has an antenna, and a metal member is mentioned. Moreover, the structure which provided the composite magnetic body between the antenna provided in the base sheet of the IC card and the metal member by arranging the surface sheet of the non-contact IC card so as to face the metal member. .
　このように、ＩＣカード中のアンテナと金属部材の間に、上記複合磁性体を介在させることにより、電磁波のエネルギーが通信装置中の金属部材により吸収されることなく、磁力線の信号エネルギーの減衰を抑制することができる。その結果、通信装置とリーダーまたはリーダー／ライターとの通信距離を長くとることができる。 In this way, by interposing the composite magnetic body between the antenna and the metal member in the IC card, the energy of electromagnetic waves is not absorbed by the metal member in the communication device, and the signal energy of the magnetic field lines is attenuated. Can be suppressed. As a result, the communication distance between the communication device and the reader or reader / writer can be increased.
　本実施形態の複合磁性体によれば、磁性粉体を扁平状とし、その磁気特性を、（１）１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’が１よりも大きく、複素透磁率の損失正接ｔａｎδμが０．０２以下、複素誘電率の実部εｒ’が５０以下、複素誘電率の損失正接ｔａｎδεが０．２以下、（２）１０ＭＨｚから２０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’が１よりも大きく、複素透磁率の損失正接ｔａｎδμが０．０１以下、複素誘電率の実部εｒ’が５０以下、複素誘電率の損失正接ｔａｎδεが０．２以下、のいずれかとした。これにより、上記の各周波数帯域における磁力線の信号エネルギーの減衰を抑制することができる。 According to the composite magnetic body of the present embodiment, the magnetic powder is made flat, and the magnetic properties thereof are as follows: (1) the real part μr ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is greater than 1, Permeability loss tangent tan δμ is 0.02 or less, complex permittivity real part εr ′ is 50 or less, loss tangent tan δε of complex permittivity is 0.2 or less, and (2) complex permeability in the frequency band from 10 MHz to 20 MHz. Real part μr ′ of magnetic susceptibility is greater than 1, loss tangent tan δμ of complex permeability is 0.01 or less, real part εr ′ of complex permittivity is 50 or less, loss tangent tan δε of complex permittivity is 0.2 or less, Either. Thereby, attenuation | damping of the signal energy of the magnetic field line in each said frequency band can be suppressed.
　上記の磁性粉体の厚みを０．０１μｍ以上かつ１０μｍ以下、平均長径を０．０５μ以上かつ２０μｍ以下、かつ平均アスペクト比（長径／厚み）を５以上とした場合には、１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’が４以上、複素誘電率の実部εｒ’が５０以下の複合磁性体を得ることができる。 When the thickness of the magnetic powder is 0.01 μm or more and 10 μm or less, the average major axis is 0.05 μm or more and 20 μm or less, and the average aspect ratio (major axis / thickness) is 5 or more, the frequency ranges from 10 MHz to 70 MHz. A composite magnetic body having a real part μr ′ of complex permeability in the frequency band of 4 or more and a real part εr ′ of complex permittivity of 50 or less can be obtained.
　上記の磁性粉体を、アルミニウム（Ａｌ）、クロム（Ｃｒ）、マンガン（Ｍｎ）、コバルト（Ｃｏ）、銅（Ｃｕ）、亜鉛（Ｚｎ）、ニオブ（Ｎｂ）、モリブデン（Ｍｏ）、インジウム（Ｉｎ）、スズ（Ｓｎ）の群から選択される１種または２種以上の金属元素を含む鉄－ニッケル合金とした場合には、高いμｒ’の複合磁性体を得ることができる。 The magnetic powder is made of aluminum (Al), chromium (Cr), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), niobium (Nb), molybdenum (Mo), indium (In ) And an iron-nickel alloy containing one or more metal elements selected from the group of tin (Sn), a high μr ′ composite magnetic body can be obtained.
　上記の磁性粉体が、平均粒子径が３μｍ以下の球状の磁性粒子に機械的応力を加えることにより、この球状の磁性粒子同士を変形及び融着されることにより得られた磁性粉体であれば、アスペクト比が高い、すなわち高いμｒ’の複合磁性体を得ることができる。 The above magnetic powder may be a magnetic powder obtained by applying mechanical stress to spherical magnetic particles having an average particle diameter of 3 μm or less and deforming and fusing the spherical magnetic particles together. For example, a composite magnetic body having a high aspect ratio, that is, a high μr ′ can be obtained.
　本実施形態の複合磁性体の製造方法によれば、平均粒子径が３μｍ以下の球状の磁性粒子を界面活性剤を含む溶液中に分散してなるスラリー及び分散媒体を、密閉可能な容器内に、このスラリー及び分散媒体の合計の体積量が容器内の体積と同じくなるように充填し、このスラリーを分散媒体と共に密閉状態にて撹拌し、球状の磁性粒子同士を変形及び融着させて扁平状の磁性粉体とする第１の工程と、この扁平状の磁性粉体を、液状の樹脂中または樹脂を溶媒に溶解した溶液中に分散し混合して成形材料とする第２の工程と、この成形材料を成形または基材上に塗布し、乾燥し、熱処理または焼成する第３の工程とを有する。これにより、磁性粉体の厚みのばらつきが極めて小さく、ｔａｎδμ、ｔａｎδεの低い扁平状の複合磁性体を容易に得ることができる。また、得られた扁平状の磁性粉体は、不規則な衝撃を受けることもなく、割れや欠け等が生じる虞もない。 According to the method for producing a composite magnetic body of this embodiment, a slurry and a dispersion medium obtained by dispersing spherical magnetic particles having an average particle diameter of 3 μm or less in a solution containing a surfactant are placed in a sealable container. The slurry and the dispersion medium are filled so that the total volume is the same as the volume in the container, and the slurry is stirred together with the dispersion medium in a sealed state to deform and fuse the spherical magnetic particles with each other. A first step of forming a magnetic powder, and a second step of dispersing and mixing the flat magnetic powder in a liquid resin or a solution in which a resin is dissolved in a solvent to obtain a molding material; And a third step in which the molding material is molded or coated on a substrate, dried, heat-treated or fired. As a result, a flat composite magnetic body having a very small variation in thickness of the magnetic powder and low tan δμ and tan δε can be easily obtained. Further, the obtained flat magnetic powder is not subjected to irregular impacts, and there is no possibility of cracking or chipping.
　さらに、密閉容器の体積が１Ｌ以上のものを用いて磁性粉体を製造すると、球状の磁性粒子を実質的に含まない扁平状の複合磁性体が得られるので、よりμｒ’が大きい扁平状の複合磁性体を得ることができる。 Furthermore, when a magnetic powder is produced using a sealed container having a volume of 1 L or more, a flat composite magnetic body substantially free of spherical magnetic particles can be obtained, so that a flat shape with a larger μr ′ is obtained. A composite magnetic body can be obtained.
　本実施形態のアンテナによれば、本実施形態の複合磁性体を装荷し、かつ１０ＭＨｚから２０ＭＨｚまでの周波数帯域の電波を、送信、受信または送受信することとしたので、アンテナ効率を高めることができる。 According to the antenna of this embodiment, since the composite magnetic body of this embodiment is loaded and radio waves in the frequency band from 10 MHz to 20 MHz are transmitted, received, or transmitted / received, the antenna efficiency can be improved. .
　本実施形態の非接触ＩＣカードによれば、本実施形態の複合磁性体を備えたので、非接触ＩＣカードの表面側に金属部材が存在しても、その金属部材による磁力線の信号エネルギーの減衰を抑制することができる。その結果、非接触ＩＣカードとリーダーまたはリーダー／ライターとの通信距離を長くとることができる。 According to the non-contact IC card of the present embodiment, since the composite magnetic body of the present embodiment is provided, even if a metal member is present on the surface side of the non-contact IC card, the signal energy of magnetic field lines is attenuated by the metal member. Can be suppressed. As a result, the communication distance between the non-contact IC card and the reader or reader / writer can be increased.
　本実施形態の通信装置によれば、上記の複合磁性体をアンテナと金属部材との間に設けたので、電磁波のエネルギーが金属部材により吸収されることなく、磁気シールド材としての性能を保ちつつ、磁力線の信号エネルギーの減衰を抑制することができる。その結果、通信装置とリーダーまたはリーダー／ライターとの通信距離を長くとることができる。 According to the communication device of the present embodiment, since the composite magnetic body is provided between the antenna and the metal member, the energy of electromagnetic waves is not absorbed by the metal member, and the performance as a magnetic shield material is maintained. The attenuation of the signal energy of the magnetic lines of force can be suppressed. As a result, the communication distance between the communication device and the reader or reader / writer can be increased.
　以下、実施例及び比較例により本発明を具体的に説明するが、本発明はこれらの実施例によって限定されるものではない。 Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
［実施例１］
「第１の工程」
　Ｎｉ７５質量％－Ｆｅ２０質量％－Ｚｎ５質量％のＮｉ－Ｆｅ－Ｚｎ合金からなる平均粒径０．２５μｍの球状の磁性粒子２００ｇを、界面活性剤として窒素含有のグラフトポリマーを溶解したキシレン８００ｇに混合し、スラリーを作製した。
　次いで、密閉容器として、図２に示すような循環密閉型で容器体積が５Ｌのサンドミル　ウルトラアペックスミルＵＡＭ－５（寿工業社製）を用い、この密閉容器内に、分散媒体として平均粒径５０μｍのジルコニアビーズを投入し、次いで、上記のスラリーを投入し、密閉容器内を満たした。 [Example 1]
"First step"
200 g of spherical magnetic particles having an average particle diameter of 0.25 μm made of Ni—Fe—Zn alloy of Ni 75 mass% —Fe 20 mass% —Zn 5 mass% are mixed with 800 g of xylene in which a nitrogen-containing graft polymer is dissolved as a surfactant. Thus, a slurry was prepared.
Next, a sand mill Ultra Apex Mill UAM-5 (manufactured by Kotobuki Kogyo Co., Ltd.) having a circulation volume of 5 L and having a volume of 5 L as shown in FIG. 2 is used as the hermetic container. Zirconia beads were charged, and then the above slurry was charged to fill the sealed container.
　この状態で、一軸回転体の径方向の外周端付近の流速が１０ｍ／秒以上となるような回転数で攪拌し、平均厚みが０．３μｍ、平均長径が２．８μｍ、平均アスペクト比が９．３の扁平状の磁性粉体を作製した。 In this state, stirring is performed at a rotational speed such that the flow velocity near the radial outer periphery of the uniaxial rotating body is 10 m / second or more, the average thickness is 0.3 μm, the average major axis is 2.8 μm, and the average aspect ratio is 9 .3 flat magnetic powder was produced.
「第２の工程」
　次いで、得られた扁平状の磁性粉体を乾燥して溶媒を散逸させた後、この扁平状の磁性粉体の所定量を、ポリスチレン樹脂をトルエンに溶解して得られる樹脂溶液に添加して撹拌混合した。 "Second step"
Next, after drying the obtained flat magnetic powder to dissipate the solvent, a predetermined amount of this flat magnetic powder is added to a resin solution obtained by dissolving polystyrene resin in toluene. Stir and mix.
　次いで、得られた扁平状の磁性粉体を乾燥して溶媒を散逸させた後、この扁平状の磁性粉体の所定量を、ポリスチレン樹脂をトルエンに溶解して得られる樹脂溶液に添加して撹拌混合した。ここでは、磁性粉体とポリスチレン樹脂との合計の体積中に、磁性粉体が４０体積％となるように混合した。 Next, after drying the obtained flat magnetic powder to dissipate the solvent, a predetermined amount of this flat magnetic powder is added to a resin solution obtained by dissolving polystyrene resin in toluene. Stir and mix. Here, the magnetic powder was mixed so as to be 40% by volume in the total volume of the magnetic powder and the polystyrene resin.
「第３の工程」
　このようにして得られた混合物を、ドクターブレード法により１００ｍｍ角、厚み６００μｍの正方形状のフィルムに成形した。
　次いで、このフィルムを大気中、８０℃にて２０分間乾燥し、厚みが１００μｍのドライフィルムとし、その後、減圧プレス装置にてプレス焼成を行った。プレス条件は、常圧のまま９０℃まで２０分で昇温させ、その後２ＭＰａの圧力を加えて１０分間保持し、実施例１の複合磁性体を得た。 "Third process"
The mixture thus obtained was molded into a square film having a size of 100 mm square and a thickness of 600 μm by the doctor blade method.
Next, this film was dried in the atmosphere at 80 ° C. for 20 minutes to obtain a dry film having a thickness of 100 μm, and then press firing was performed with a reduced-pressure press apparatus. The pressing condition was that the temperature was raised to 90 ° C. over 20 minutes while maintaining the normal pressure, and then a pressure of 2 MPa was applied and held for 10 minutes to obtain the composite magnetic body of Example 1.
　この複合磁性体の１０ＭＨｚから１００ＭＨｚにおけるμｒ’、μｒ”、ｔａｎδμ、εｒ’、εｒ”、ｔａｎδεをマテリアルアナライザー　Ｅ４９９１Ａ型（Agilent Technologies社製）にて測定した。複素透磁率の実部μｒ’、複素透磁率の虚部μｒ”及び複素透磁率の損失正接ｔａｎδμの測定結果を図３に、複素誘電率の実部εｒ’、複素誘電率の虚部εｒ”及び複素誘電率の損失正接ｔａｎδεの測定結果を図４に、それぞれ示す。
　また、１３．５６ＭＨｚにおけるμｒ’は９、μｒ”は０．０８、ｔａｎδμは０．００９、εｒ’は２５．７、εｒ”は２．８、ｔａｎδεは０．１１であった。 Μr ′, μr ″, tan δμ, εr ′, εr ″, and tanδε of this composite magnetic material at 10 to 100 MHz were measured with a material analyzer E4991A type (manufactured by Agilent Technologies). The measurement results of the real part μr ′ of the complex permeability, the imaginary part μr ″ of the complex permeability, and the loss tangent tan δμ of the complex permeability are shown in FIG. 3, the real part εr ′ of the complex permittivity, the imaginary part εr ″ of the complex permittivity 4 shows the measurement results of the loss tangent tan δε of the complex dielectric constant.
At 13.56 MHz, μr ′ was 9, μr ″ was 0.08, tan δμ was 0.009, εr ′ was 25.7, εr ″ was 2.8, and tan δε was 0.11.
　この複合磁性体中の磁性粉体の形状を走査型電子顕微鏡（ＳＥＭ）により観察したところ、扁平状の磁性粉体５０個の平均の厚みは０．３μｍ、平均長径は２．８μｍであり、個々のアスペクト比の平均値は９．３であった。
　また、この走査型電子顕微鏡像（ＳＥＭ像）の視野内では、扁平状の磁性粉体しか認められず、球状の磁性粒子や、厚み、長さまたはアスペクト比が、この扁平状の磁性粉体から外れた磁性粒子は、実質的に認められなかった。 When the shape of the magnetic powder in the composite magnetic material was observed with a scanning electron microscope (SEM), the average thickness of 50 flat magnetic powders was 0.3 μm, and the average major axis was 2.8 μm. The average value of the individual aspect ratios was 9.3.
Further, only a flat magnetic powder is observed within the field of view of this scanning electron microscope image (SEM image), and the spherical magnetic particles and the flat magnetic powder have a thickness, length or aspect ratio. Magnetic particles deviating from the above were not substantially observed.
［比較例１］
　Ｎｉ７５質量％－Ｆｅ２０質量％－Ｚｎ５質量％のＮｉ－Ｆｅ－Ｚｎ合金からなる平均粒径０．２５μｍの球状の磁性粒子（アスペクト比：１）２００ｇを、界面活性剤として窒素含有のグラフトポリマーを溶解したキシレン８００ｇに混合し、スラリーを作製した。
　次いで、実施例１と同様にして、この扁平状の磁性粉体の所定量を、ポリスチレン樹脂をトルエンに溶解して得られる樹脂溶液に添加して撹拌混合した。ここでは、磁性粉体とポリスチレン樹脂との合計の体積中に、磁性粉体が４０体積％となるように混合した。 [Comparative Example 1]
200 g of spherical magnetic particles having an average particle diameter of 0.25 μm (aspect ratio: 1) made of Ni—Fe—Zn alloy of Ni 75 mass% —Fe 20 mass% —Zn 5 mass%, and a nitrogen-containing graft polymer as a surfactant A slurry was prepared by mixing with 800 g of dissolved xylene.
Next, in the same manner as in Example 1, a predetermined amount of the flat magnetic powder was added to a resin solution obtained by dissolving a polystyrene resin in toluene and mixed with stirring. Here, the magnetic powder was mixed so as to be 40% by volume in the total volume of the magnetic powder and the polystyrene resin.
　得られた混合物を、実施例１と同様にしてドクターブレード法により１００ｍｍ角、厚み６００μｍの正方形状のフィルムに成形した。
　次いで、このフィルムを大気中、８０℃にて２０分間乾燥し、厚みが１００μｍのドライフィルムとし、その後、減圧プレス装置にてプレス焼成を行った。プレス条件は、常圧のまま９０℃まで２０分で昇温させ、その後２ＭＰａの圧力を加えて１０分間保持し、比較例１の複合磁性体を得た。 The obtained mixture was formed into a square film having a 100 mm square and a thickness of 600 μm by the doctor blade method in the same manner as in Example 1.
Next, this film was dried in the atmosphere at 80 ° C. for 20 minutes to obtain a dry film having a thickness of 100 μm, and then press firing was performed with a reduced-pressure press apparatus. The pressing condition was that the temperature was raised to 90 ° C. over 20 minutes at normal pressure, and then a pressure of 2 MPa was applied and held for 10 minutes to obtain a composite magnetic body of Comparative Example 1.
　この複合磁性体の１０ＭＨｚから１００ＭＨｚにおけるμｒ’、μｒ”、ｔａｎδμをマテリアルアナライザー　Ｅ４９９１Ａ型（Agilent Technologies社製）にて測定したところ、１３．５６ＭＨｚにおけるμｒ’は３．８、μｒ”は０．２８、ｔａｎδμは０．０７であった。 Μr ′, μr ″ and tan δμ of this composite magnetic material from 10 MHz to 100 MHz were measured with a material analyzer E4991A type (manufactured by Agilent Technologies), μr ′ at 13.56 MHz was 3.8, and μr ″ was 0.28. , Tan δμ was 0.07.
［実施例２］
　裏面シート、ＩＣチップが接続されたループアンテナを有する基体シート、実施例１の複合磁性体、及び表面シートを順次積層させて固着させることにより、実施例２のＩＣカードを得た。 [Example 2]
An IC card of Example 2 was obtained by sequentially laminating a back sheet, a base sheet having a loop antenna to which an IC chip was connected, a composite magnetic body of Example 1, and a top sheet, and fixing them.
［比較例２］
　実施例１の複合磁性体を用いる替わりに、比較例１の複合磁性体を用いた以外は、実施例２と同様にして、比較例２のＩＣカードを得た。 [Comparative Example 2]
Instead of using the composite magnetic material of Example 1, an IC card of Comparative Example 2 was obtained in the same manner as Example 2 except that the composite magnetic material of Comparative Example 1 was used.
　実施例２のＩＣカード及び比較例２のＩＣカードそれぞれの表面シート側に金属板を重ね合わせた状態で、通信できる距離を測定したところ、実施例２のＩＣカードは、比較例２のＩＣカードと比べて通信距離が長いことが確認された。 When the distance at which communication was possible with the metal plate superimposed on the surface sheet side of each of the IC card of Example 2 and the IC card of Comparative Example 2 was measured, the IC card of Example 2 was the IC card of Comparative Example 2 It was confirmed that the communication distance was longer than that.
［実施例３］
「第１の工程」
　Ｎｉ７５質量％－Ｆｅ２０質量％－Ｚｎ５質量％のＮｉ－Ｆｅ－Ｚｎ合金からなる平均粒径０．２５μｍの球状の磁性粒子の替わりに、Ｎｉ７８質量％－Ｆｅ２２質量％のＮｉ－Ｆｅ合金からなる平均粒径０．３μｍの球状の磁性粒子を用いた以外は、実施例１の第１の工程と同様にして、実施例３の磁性粉体を得た。
　得られた磁性粉体は、平均厚みが０．２μｍ、平均長径が１．９μｍ、平均アスペクト比が９．５の扁平状であった。 [Example 3]
"First step"
Instead of spherical magnetic particles with an average particle diameter of 0.25 μm consisting of Ni—Fe—Zn alloy of Ni 75 mass% —Fe 20 mass% —Zn 5 mass%, an average consisting of Ni—Fe alloy of Ni 78 mass% —Fe 22 mass% A magnetic powder of Example 3 was obtained in the same manner as in the first step of Example 1, except that spherical magnetic particles having a particle size of 0.3 μm were used.
The obtained magnetic powder had a flat shape with an average thickness of 0.2 μm, an average major axis of 1.9 μm, and an average aspect ratio of 9.5.
「第２及び第３の工程」
　この扁平状の磁性粉体を用い、実施例１の第２及び第３の工程と同様にして、実施例３の複合磁性体を得た。
　この複合磁性体の１３．５６ＭＨｚにおけるμｒ’、μｒ’’、ｔａｎδμ、εｒ’、εｒ”及びｔａｎδεを、実施例１と同様にして測定した。その結果、μｒ’は１０、μｒ”は０．０８、ｔａｎδμは０．００８、εｒ’は２４．６、εｒ”は２．７、ｔａｎδεは０．１１であった。 "Second and third steps"
Using this flat magnetic powder, a composite magnetic body of Example 3 was obtained in the same manner as in the second and third steps of Example 1.
Μr ′, μr ″, tan δμ, εr ′, εr ″ and tanδε at 13.56 MHz of this composite magnetic material were measured in the same manner as in Example 1. As a result, μr ′ was 10 and μr ″ was 0. 08, tan δμ was 0.008, εr ′ was 24.6, εr ″ was 2.7, and tan δε was 0.11.
　この複合磁性体中の磁性粉体の形状を走査型電子顕微鏡（ＳＥＭ）により観察したところ、扁平状の磁性粉体５０個の平均の厚みは０．２μｍ、平均長径は１．９μｍであり、個々のアスペクト比の平均値は９．５であった。
　また、この走査型電子顕微鏡像（ＳＥＭ像）の視野内では、扁平状の磁性粉体しか認められず、球状の磁性粒子や、厚み、長さまたはアスペクト比が上記の扁平状の磁性粉体から外れた磁性粒子は認められなかった。 When the shape of the magnetic powder in the composite magnetic material was observed with a scanning electron microscope (SEM), the average thickness of 50 flat magnetic powders was 0.2 μm, and the average major axis was 1.9 μm. The average value of the individual aspect ratios was 9.5.
Further, only the flat magnetic powder is recognized within the field of view of the scanning electron microscope image (SEM image), and the spherical magnetic particles or the flat magnetic powder having the thickness, length or aspect ratio described above are used. Magnetic particles deviating from the above were not observed.
［実施例４］
「第１の工程」
　Ｎｉ７５質量％－Ｆｅ２０質量％－Ｚｎ５質量％のＮｉ－Ｆｅ－Ｚｎ合金からなる平均粒径０．２５μｍの球状の磁性粒子の替わりに、Ｎｉ７８質量％－Ｆｅ２２質量％のＮｉ－Ｆｅ合金からなる平均粒径０．３μｍの球状の磁性粒子を用いた以外は、実施例１の第１の工程と同様にして、実施例４の磁性粉体を得た。
　得られた磁性粉体は、平均厚みが０．２μｍ、平均長径が１．９μｍ、平均アスペクト比が９．５の扁平状であった。 [Example 4]
"First step"
Instead of spherical magnetic particles with an average particle diameter of 0.25 μm consisting of Ni—Fe—Zn alloy of Ni 75 mass% —Fe 20 mass% —Zn 5 mass%, an average consisting of Ni—Fe alloy of Ni 78 mass% —Fe 22 mass% A magnetic powder of Example 4 was obtained in the same manner as in the first step of Example 1, except that spherical magnetic particles having a particle diameter of 0.3 μm were used.
The obtained magnetic powder had a flat shape with an average thickness of 0.2 μm, an average major axis of 1.9 μm, and an average aspect ratio of 9.5.
「第２及び第３の工程」
　この扁平状の磁性粉体を用い、ポリスチレン樹脂の替わりに、ポリスチレン樹脂とスチレン・ブタジエン系熱可塑性エラストマーを５０：５０の質量比で混合した樹脂を用い、磁性粉体とポリスチレン樹脂とスチレン・ブタジエン系熱可塑性エラストマーの合計体積中に、磁性粉体が４０体積％となるように混合した以外は、実施例１と同様にして、実施例４の複合磁性体を得た。 "Second and third steps"
Using this flat magnetic powder, instead of polystyrene resin, using a resin in which polystyrene resin and styrene / butadiene thermoplastic elastomer are mixed at a mass ratio of 50:50, magnetic powder, polystyrene resin and styrene / butadiene are used. A composite magnetic body of Example 4 was obtained in the same manner as in Example 1 except that the magnetic powder was mixed so as to be 40% by volume in the total volume of the thermoplastic elastomer.
　この複合磁性体のμｒ’、μｒ’’、ｔａｎδμ、εｒ’、εｒ”、ｔａｎδεを、実施例１と同様にして測定した。その結果、μｒ’は１０、μｒ”は０．０８、ｔａｎδμは０．００８、εｒ’は３０．３、εｒ”は３．８、ｔａｎδεは０．１３であった。 Μr ′, μr ″, tan δμ, εr ′, εr ″, and tanδε of this composite magnetic material were measured in the same manner as in Example 1. As a result, μr ′ was 10, μr ″ was 0.08, and tan δμ was 0.008, εr ′ was 30.3, εr ″ was 3.8, and tan δε was 0.13.
　この複合磁性体中の磁性粉体の形状を走査型電子顕微鏡（ＳＥＭ）により観察したところ、扁平状の磁性粉体５０個の平均の厚みは０．２μｍ、平均長径は１．９μｍであり、個々のアスペクト比の平均値は９．５であった。
　また、この走査型電子顕微鏡像（ＳＥＭ像）の視野内では、扁平状の磁性粉体しか認められず、球状の磁性粒子や、厚み、長径またはアスペクト比が、上記の扁平状の磁性粉体から外れた磁性粒子は認められなかった。 When the shape of the magnetic powder in the composite magnetic material was observed with a scanning electron microscope (SEM), the average thickness of 50 flat magnetic powders was 0.2 μm, and the average major axis was 1.9 μm. The average value of the individual aspect ratios was 9.5.
Further, only flat magnetic powder is recognized within the field of view of this scanning electron microscope image (SEM image), and spherical magnetic particles and the above-mentioned flat magnetic powder having a thickness, a long diameter or an aspect ratio of Magnetic particles deviating from the above were not observed.
［比較例３］
　Ｎｉ７８質量％－Ｆｅ２２質量％のＮｉ－Ｆｅ合金からなる平均粒径０．３μｍの球状の磁性粒子（アスペクト比：１）２００ｇを、界面活性剤として窒素含有のグラフトポリマーを溶解したキシレン８００ｇに混合し、スラリーを作製した。
　次いで、実施例１と同様にして、この扁平状の磁性粉体の所定量を、ポリスチレン樹脂をトルエンに溶解して得られる樹脂溶液に添加して撹拌混合した。ここでは、磁性粉体の総体積がポリスチレン樹脂に対して４０体積％になるように混合した。
　得られた混合物を用いて、実施例１と同様にして、比較例３の複合磁性体を得た。
　この複合磁性体の、１３．５６ＭＨｚにおけるμｒ’は３．１、μｒ”は０．２７、ｔａｎδμは０．０９であった。 [Comparative Example 3]
200 g of spherical magnetic particles (aspect ratio: 1) composed of Ni-Fe alloy of Ni 78 mass% -Fe 22 mass% and having an average particle diameter of 0.3 μm are mixed with 800 g of xylene in which a nitrogen-containing graft polymer is dissolved as a surfactant. Thus, a slurry was prepared.
Next, in the same manner as in Example 1, a predetermined amount of the flat magnetic powder was added to a resin solution obtained by dissolving a polystyrene resin in toluene and mixed with stirring. Here, mixing was performed so that the total volume of the magnetic powder was 40% by volume with respect to the polystyrene resin.
A composite magnetic body of Comparative Example 3 was obtained in the same manner as Example 1 using the obtained mixture.
This composite magnetic body had a μr ′ of 3.1, a μr ″ of 0.27, and a tan δμ of 0.09 at 13.56 MHz.
［実施例５］
　裏面シート、ＩＣチップが接続されたループアンテナを有する基体シート、実施例３の複合磁性体、及び表面シートを順次積層させて固着させることにより、実施例５のＩＣカードを得た。 [Example 5]
An IC card of Example 5 was obtained by sequentially laminating a back sheet, a base sheet having a loop antenna to which an IC chip was connected, a composite magnetic body of Example 3, and a top sheet, and fixing them.
［実施例６］
　裏面シート、ＩＣチップが接続されたループアンテナを有する基体シート、実施例４の複合磁性体、及び表面シートを順次積層させて固着させることにより、実施例６のＩＣカードを得た。 [Example 6]
An IC card of Example 6 was obtained by sequentially laminating a back sheet, a base sheet having a loop antenna to which an IC chip was connected, a composite magnetic body of Example 4, and a top sheet, and fixing them.
［比較例４］
　裏面シート、ＩＣチップが接続されたループアンテナを有する基体シート、比較例３の複合磁性体、及び表面シートを順次積層させて固着させることにより、比較例４のＩＣカードを得た。 [Comparative Example 4]
A back sheet, a base sheet having a loop antenna to which an IC chip was connected, a composite magnetic body of Comparative Example 3 and a front sheet were sequentially laminated and fixed to obtain an IC card of Comparative Example 4.
　実施例５、実施例６及び比較例４のＩＣカードそれぞれの表面シート側に金属板を重ね合わせた状態で、通信可能な距離を測定したところ、実施例５及び６のＩＣカードは、比較例４のＩＣカードと比べて通信距離が長いことが確認された。 When the communicable distance was measured in the state where the metal plate was superimposed on the surface sheet side of each of the IC cards of Example 5, Example 6 and Comparative Example 4, the IC cards of Examples 5 and 6 were comparative examples. It was confirmed that the communication distance was longer than that of the IC card 4.
　１０ＭＨｚから７０ＭＨｚまでの周波数帯域に適用可能であり、しかも、この周波数帯域における複素透磁率の実部μｒ’が大きく、かつ複素透磁率の損失正接ｔａｎδμ、複素誘電率の実部εｒ’及び複素誘電率の損失正接ｔａｎδεが低い複合磁性体及びそれを備えたアンテナ並びに非接触ＩＣカードを提供することができる。 Applicable to a frequency band from 10 MHz to 70 MHz, and the real part μr ′ of the complex permeability in this frequency band is large, the loss tangent tan δμ of the complex permeability, the real part εr ′ of the complex dielectric constant, and the complex dielectric It is possible to provide a composite magnetic body having a low loss tangent tan δε, an antenna including the same, and a non-contact IC card.
　１　　開放容器
　２　　球状の磁性粒子
　３　　スラリー
　４　　分散媒体
　５　　一軸回転体
　５ａ　　外周端
　１１　　密閉容器 DESCRIPTION OF SYMBOLS 1 Open container 2 Spherical magnetic particle 3 Slurry 4 Dispersion medium 5 Uniaxial rotating body 5a Outer peripheral end 11 Sealed container

Claims (7)

  1. 　磁性粉体を絶縁材料中に分散してなる複合磁性体において、
    　前記磁性粉体は扁平状であり、
    　１０ＭＨｚから７０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’は１よりも大きく、複素透磁率の損失正接ｔａｎδμは０．０２以下、複素誘電率の実部εｒ’は５０以下、複素誘電率の損失正接ｔａｎδεは０．２以下である複合磁性体。     In a composite magnetic body in which magnetic powder is dispersed in an insulating material,
    The magnetic powder is flat,
    The real part μr ′ of the complex permeability in the frequency band from 10 MHz to 70 MHz is greater than 1, the loss tangent tan δμ of the complex permeability is 0.02 or less, the real part εr ′ of the complex permittivity is 50 or less, and the complex permittivity A composite magnetic body having a loss tangent tan δε of 0.2 or less.
  2. 　磁性粉体を絶縁材料中に分散してなる複合磁性体において、
    　前記磁性粉体は扁平状であり、
    　１０ＭＨｚから２０ＭＨｚまでの周波数帯域における複素透磁率の実部μｒ’は１よりも大きく、複素透磁率の損失正接ｔａｎδμは０．０１以下、複素誘電率の実部εｒ’は５０以下、複素誘電率の損失正接ｔａｎδεは０．２以下である複合磁性体。     In a composite magnetic body in which magnetic powder is dispersed in an insulating material,
    The magnetic powder is flat,
    The real part μr ′ of the complex permeability in the frequency band from 10 MHz to 20 MHz is greater than 1, the loss tangent tan δμ of the complex permeability is 0.01 or less, the real part εr ′ of the complex permittivity is 50 or less, and the complex permittivity A composite magnetic body having a loss tangent tan δε of 0.2 or less.
  3. 　前記磁性粉体の平均厚みは０．０１μｍ以上かつ１０μｍ以下、平均長径は０．０５μｍ以上かつ２０μｍ以下、かつ平均アスペクト比（長径／厚み）は５以上である請求項１または２記載の複合磁性体。 3. The composite magnetism according to claim 1, wherein the magnetic powder has an average thickness of 0.01 μm to 10 μm, an average major axis of 0.05 μm to 20 μm, and an average aspect ratio (major axis / thickness) of 5 or more. body.
  4. 　前記磁性粉体は、アルミニウム（Ａｌ）、クロム（Ｃｒ）、マンガン（Ｍｎ）、コバルト（Ｃｏ）、銅（Ｃｕ）、亜鉛（Ｚｎ）、ニオブ（Ｎｂ）、モリブデン（Ｍｏ）、インジウム（Ｉｎ）、スズ（Ｓｎ）の群から選択される１種または２種以上の金属元素を含む鉄－ニッケル合金である請求項１ないし３のいずれか１項記載の複合磁性体。 The magnetic powder includes aluminum (Al), chromium (Cr), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), niobium (Nb), molybdenum (Mo), and indium (In). The composite magnetic body according to any one of claims 1 to 3, which is an iron-nickel alloy containing one or more metal elements selected from the group of tin (Sn).
  5. 　前記磁性粉体は、平均粒子径が３μｍ以下の球状の磁性粒子に機械的応力を加えることにより、この球状の磁性粒子同士を変形及び融着してなる請求項１ないし４のいずれか１項記載の複合磁性体。 5. The magnetic powder according to claim 1, wherein the spherical magnetic particles are deformed and fused together by applying mechanical stress to the spherical magnetic particles having an average particle diameter of 3 μm or less. The composite magnetic body described.
  6. 　請求項１ないし５のいずれか１項記載の複合磁性体を装荷してなり、
    　１０ＭＨｚから７０ＭＨｚまでの周波数帯域の電波を、送信、受信または送受信するアンテナ。     Loading the composite magnetic body according to any one of claims 1 to 5,
    An antenna that transmits, receives, or transmits / receives radio waves in a frequency band from 10 MHz to 70 MHz.
  7. 　請求項１ないし５のいずれか１項記載の複合磁性体を備えてなる非接触ＩＣカード。 A non-contact IC card comprising the composite magnetic body according to any one of claims 1 to 5.
PCT/JP2012/079932 2011-11-21 2012-11-19 Composite magnet, antenna provided therewith, and non-contact ic card WO2013077285A1 (en)

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