JP2020161726A - Composite magnetic material for high frequency - Google Patents

Abstract

To provide a novel composite magnetic material for high frequency and manufacturing method therefor, capable of solving problems such as eddy current loss because the material has higher permeability than ferrite-based magnetic material and higher electrical resistivity than metal-based magnetic material.SOLUTION: The material is formed by blending high-circularity iron powder and/or nano ceramic particle in nitride-based magnetic material with grain shape coordinated (rare earth-iron-nitrogen-based magnetic material) and using resin with high segment of solubility parameter.SELECTED DRAWING: None

Description

The present invention relates to a composite magnetic material used in a high frequency region including an ultrahigh frequency region. Specifically, composite magnetic materials for power equipment and information and communication related equipment used in the high frequency region including the ultra high frequency region, and composite magnetism for suppressing obstacles due to unnecessary electromagnetic interference in the high frequency region including the ultrahigh frequency region. Regarding materials.
Examples of the composite magnetic material for the above-mentioned power equipment and information and communication related equipment include composite magnetic materials for transformers, heads, inductors, reactors, yokes, cores (magnetic cores), antennas, and micros. Composite magnetic materials for wave elements, magnetic distortion elements, magnetic acoustic elements, magnetic recording elements, etc., and magnetic fields for Hall sensors (Hall elements), magnetic sensors, current sensors, rotation sensors, electronic compasses, etc. It relates to a composite magnetic material for sensors and the like, and in particular, there is a composite magnetic material for a coil core and an antenna core used in a wireless power feeding (also called wireless power transmission or non-contact power transmission) system.
Examples of the composite magnetic material for suppressing obstacles due to unnecessary electromagnetic interference include composite magnetic materials for electromagnetic noise absorption, electromagnetic wave absorption, magnetic shield, etc., composite magnetic materials for inductor elements such as noise removal inductors, and the like. , RFID (Radio Frequency Identification) tag composite magnetic material and noise filter composite magnetic material that removes noise from signals at high frequencies.

The "composite magnetic material for high frequency" in the present application is defined by combining two or more different magnetic materials, or one or more magnetic materials and a non-magnetic material (for example, a non-magnetic ceramic material and / or resin). It is a magnetic material that functions as a magnetic material used in the high frequency region (so-called magnetic material for high frequency). In the present application, the term "composite" refers to a state in which a region occupied by a magnetic material is divided or covered with a non-magnetic material.
In the present application, an electromagnetic wave having a frequency of 0.005 GHz or more and 100 GHz or less is referred to as "high frequency", and among them, "ultra high frequency" means a high frequency of 1 GHz or more. Unless otherwise specified in the present application, "ultra-high frequency" is also included in "high frequency". Therefore, the "high frequency region" referred to in the present application refers to an electromagnetic wave region having a frequency of 0.005 GHz or more and 100 GHz or less, and an electromagnetic wave region having a frequency of 1 GHz or more in the electromagnetic wave region refers to an "ultra high frequency region".
Further, in the present application, unless otherwise specified, an electromagnetic wave having a frequency lower than the above-mentioned "high frequency" is referred to as "low frequency".
The "high-frequency magnetic material resin composite material" in the present application includes a resin among the high-frequency composite magnetic materials. Further, the "magnetic material for high frequency" in the present application is a magnetic material that acts on an electric field, a magnetic field or an electromagnetic field in the frequency range of 0.005 GHz to 100 GHz or less to perform a "target function", and is a "composite magnetic material for high frequency". Is included in this. In the present application, the "high frequency composite magnetic material" may be simply referred to as "composite magnetic material", and the "high frequency magnetic material resin composite magnetic material" may be simply referred to as "magnetic material resin composite magnetic material". Here, the "target function" refers to a magnetic function such as electromagnetic induction, self-induction, high magnetic permeability, high frequency loss, magnetostriction, magnetic domain formation, and semi-hard magnetism of a magnetic material, and is used in the present invention for "high frequency". The "composite magnetic material" is used for elements, parts, devices, etc. that utilize these functions. Among these, a magnetic material whose purpose is high magnetic permeability is called a "high frequency amplification material", and a magnetic material whose purpose is high high frequency loss is called a "high frequency absorption material".

Recently, as mobile information and communication devices such as personal computers, mobile phones, and digital cameras have become smaller and more multifunctional and the calculation processing speed has increased, the drive frequency has rapidly increased. , High frequencies, especially ultra-high frequencies, are becoming more widespread. Demand for devices such as satellite communications, mobile communications, and car navigation systems that use electromagnetic waves in the microwave band has increased significantly in recent years. For example, short-range wireless communications such as automobile toll collection systems (ETCs) and wireless LANs, and collision prevention radars. Technologies such as in-vehicle millimeter-wave radar have also begun to spread. In addition, the frequency is increasing in the field of wireless power supply systems. Low-frequency charging for home appliances such as mobile phones and automatic vacuum cleaners has become widespread, and low-frequency charging for stopped electric vehicles has also been put into practical use, but demonstration of high-frequency power supply for next-generation vehicles that are moving recently. Tests have also been conducted, and high-power wireless power supply from power plants using microwaves is being considered. With the progress of the use of high frequencies, especially ultra-high frequencies, as described above, there is a strong demand for magnetic materials that can cope with changes in electromagnetic fields at high frequencies without loss.
On the other hand, the deterioration of the electromagnetic environment due to the electromagnetic waves emitted by these high-frequency devices to the outside world (specifically, electromagnetic interference to other devices and living organisms) has been regarded as a problem, and currently public institutions and international organizations The movement of legal regulation and self-regulation is becoming active. As described above, it is very difficult to deal with this problem because a signal (electromagnetic wave) useful in each device may be an obstacle to other devices or a living body. In order to solve this problem, as a characteristic of the equipment, it does not emit unnecessary electromagnetic waves (electromagnetic noise) and has strong resistance to external noise, that is, electromagnetic interference (EMI: Electro-Magnetic Interference). It is important to establish electromagnetic compatibility (EMC: Electro-Magnetic Compatibility) with a view to both sides of damage (EMS: Electro-Magnetic Susceptibility).

As an example of the above EMC countermeasures, the electromagnetic noise absorbing materials that are often used in electronic devices these days will be mainly described below.
The electromagnetic noise absorbing material is a material having a function of suppressing the emission of electromagnetic waves to the outside world in the vicinity of the electromagnetic noise generation source. In the high frequency region of several hundred MHz or more, a sheet-like sheet that absorbs high-frequency electromagnetic noise such as harmonics transmitted through the line using natural resonance such as Ni-Zn ferrite and converts it into thermal energy to suppress the noise. Electromagnetic noise absorbing materials are often used. The required magnetic properties are two points: a high relative permeability of the magnetic material and a high natural resonance frequency. Since ferrite, an oxide magnetic material, has a high electrical resistivity, performance deterioration due to eddy current loss is small, and it has been regarded as a preferable material for use in a high frequency region.

On the other hand, as described in Patent Document 1, since the value of the imaginary term of the magnetic permeability of ferritic in the ultra-high frequency region is about 1 to 2 or less, the ferrite-based oxide magnetic material is in the GHz band. It is difficult to apply to electromagnetic noise absorbing materials in (region). For this reason, in recent years, Fe and Fe-Ni alloys, Fe-Ni-Si alloys, Sendust, Fe-Cu-Nb-Si alloys and amorphous alloys, which have a higher saturation magnetization value than ferrite-based oxide magnetic materials. The use of metal-based magnetic materials such as these has become active, and magnetic material resin composite materials in which magnetic metal fine particles are dispersed in an insulating resin or the like have been developed as electromagnetic noise absorbing materials.

However, the electrical resistivity of the metallic magnetic material is 10 to 140 μΩcm, which is considerably lower than the electrical resistivity of ferrite 4000 to 10 ¹⁸ μΩcm. Therefore, it is not possible to realize high magnetic permeability up to a high frequency, and it is difficult to use it in a high frequency region. This is because an insulating layer is required to prevent the magnetic permeability from starting to decrease from a low frequency region due to eddy current loss, so that the high frequency of the magnetic material resin composite material originally possessed by the non-magnetic part of the insulating layer. This is because the complex relative magnetic permeability of the region will be lowered. Further, in the ultra-high frequency region exceeding 1 GHz, even with such a composite material, a decrease in magnetic permeability due to the influence of eddy current loss is unavoidable.

Further, although a metal-based magnetic material having shape anisotropy has been developed, it is necessary to make the thickness of the metal-based magnetic material filler less than 0.2 μm based on the same consideration as in Patent Document 1. Even if the filling rate is increased to some extent and the magnetic permeability is increased, there is a limit to its application to ultra-high frequency applications.
Therefore, in the high frequency region (especially in the ultra high frequency region), the magnetic material for electromagnetic noise absorbing material, which has higher magnetic permeability and excellent electromagnetic noise suppression performance, and also for applications where mass production is easy and flexibility is required. The development of an electromagnetic noise absorbing material having a wide applicable range (for example, a magnetic material that can be dispersed in a resin to form a sheet) has been strongly desired.

For this reason, as an excellent high-frequency magnetic material, for example, even if it is used as a high-frequency absorbing material for suppressing / absorbing spurious or electromagnetic noise in an electromagnetic noise absorbing material, a high-frequency core (magnetic core) or Even if it is used as a material for RFID tags or a high-frequency amplification material for generating a magnetic field or electromagnetic field amplified in proportion to the magnetic field or electromagnetic wave of the frequency used, such as the core of a coil for a wireless power supply system, it is in the high-frequency region (necessarily Therefore, it is important that the value of the real term of the complex ratio magnetic permeability does not decrease and the value of the imaginary term does not increase up to the ultra-high frequency region).
In addition, when used as a high frequency absorbing material, the value of the imaginary term of complex relative permeability increases with frequency in the high frequency region (ultra high frequency region if necessary) even if it is close to 0 in the low frequency region. It is important that it is large enough at the desired frequency where unwanted radiation, harmonics, etc. are present.

Furthermore, in order to amplify the signal magnitude in the RFID tag for high frequency signals and the core of the coil for wireless power feeding systems, it is important to realize a real number term with high magnetic permeability in the frequency domain where the signal exists. Depending on the application, at the same time, it may be necessary to absorb and remove noise such as harmonics in the high frequency to ultra high frequency region without absorbing the signal on the frequency side lower than a certain frequency. In particular, the value of the imaginary term (μ ") of the complex relative permeability is close to 0 in the frequency region lower than 1 GHz, and the large imaginary term (μ") in the high frequency region (that is, the ultrahigh frequency region) A material having a value may be required (note that a material having a larger "selective absorption ratio of 1 GHz or more" defined later is a material more suitable for the above purpose).
However, conventionally, as far as the present inventors know, only the above-mentioned oxide magnetic materials and metal-based magnetic materials have been used as magnetic materials for high-frequency applications. As described above, even if an oxide magnetic material (particularly, a ferrite-based oxide magnetic material having a high electric resistance) is used, even if the problem due to eddy current loss is small, sufficient magnetic permeability cannot be obtained. Even if a metallic magnetic material is used, there is a problem that eddy current loss occurs in a low frequency region due to high magnetic permeability but low electrical resistance, and neither is suitable as a magnetic material for high frequency applications. There was a problem. Patent Document 1 attempts to solve this problem by using a nitride material, but the materials disclosed in the patent document include, for example, an electromagnetic wave absorbing material used in a high frequency region exceeding 10 GHz and 5 to 100 MHz. It cannot exhibit sufficient performance as an electromagnetic wave amplification material used in the high frequency region.

Japanese Patent No. 5669389

The present invention has been made in view of the above problems, and is a new composite magnetic material for high frequency using a nitride-based magnetic material, specifically, rare earth-iron-nitrogen having controlled circularity and particle size. By using a based magnetic material as a magnetic material for high-frequency applications, it is possible to realize a high magnetic permeability because it has a higher magnetization than an oxide magnetic material, and because it has a higher electrical resistance than a metal material, as described above. It is an object of the present invention to provide a new composite magnetic material for high frequency that can solve problems such as eddy current loss.
Further, according to the present invention, the electric resistance of the rare earth-iron-nitrogen magnetic material can be further increased by combining the rare earth-iron-nitrogen magnetic material with the ceramic material in which the circularity and the particle size are controlled. It is a new nitride-based magnetic material that can more effectively solve the above-mentioned problems such as eddy current loss, and has high performance (specifically, high magnetic permeability). It is an object of the present invention to provide a material as a composite magnetic material for high frequency.
Furthermore, the present invention provides a new high-frequency composite magnetic material in which the rare earth-iron-nitrogen magnetic material whose circularity and particle size are controlled is dispersed in a resin which is a copolymer of segments having different solubility parameters. The purpose is to provide.

The present inventors have a high-frequency magnetic material having excellent electromagnetic characteristics, which has contradictory characteristics of conventional magnetic materials (specifically, high magnetic permeability and high electrical resistance, and the above-mentioned eddy current loss. After diligently studying a high-frequency magnetic material with excellent electromagnetic characteristics that has the advantages of both metallic and oxide magnetic materials that can solve the problem, a composite containing rare earth-iron-nitrogen magnetic materials In magnetic materials and resin composite materials, the circularity and particle size of rare earth-iron-nitrogen magnetic materials are adjusted, and materials (for example, ceramic materials and resins) to be mixed and composited with them are appropriately selected. It has been found that a composite magnetic material for high frequency having extremely high electromagnetic characteristics can be obtained by the above, and further, the present invention has been completed by establishing a manufacturing method thereof.

That is, the present invention is as follows.
(1) The crystal structure of the main phase contains at least one rare earth-iron-nitrogen magnetic material selected from hexagonal, rhombohedral, and tetragonal, and has an average grain size of 0.1 to 2000 μm. A composite magnetic material for high frequencies, which is a powder having a diameter.
(2) The composite magnetic material for high frequencies according to (1) above, wherein the rare earth-iron-nitrogen magnetic material is represented by the following general formula.
R _x Fe _(100-xy) N _y (1)
(However, in the formula, x and y are atomic%, 3 ≦ x ≦ 30, 1 ≦ y ≦ 30, and R is Y, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Lu. , At least one selected from Sm, and when Sm is contained, Sm is less than 50 atomic% with respect to the entire R component.)
(3) 0.01 to 50 atomic% of iron constituting the rare earth-iron-nitrogen magnetic material is Co, Ni, B, Al, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, The above (1) or (2), wherein it is replaced with at least one selected from Nb, Mo, In, Hf, Ta, W, Ru, Pd, Re, Os, Ir, Ag, and Pt. Composite magnetic material for high frequency.
(4) From (1) to the above, less than 50 atomic% of nitrogen constituting the rare earth-iron-nitrogen magnetic material is replaced with at least one selected from H, C, P, Si and S. The composite magnetic material for high frequencies according to any one of (3).
(5) The composite magnetic material for high frequency according to any one of (1) to (4) above, wherein the magnetocrystalline anisotropy of the rare earth-iron-nitrogen magnetic material is in-plane magnetic anisotropy.
(6) The composite magnetic material for high frequency according to any one of (1) to (5) above, wherein the rare earth-iron-nitrogen magnetic material has a circularity of 0.6 to 1.
(7) The high frequency according to any one of (1) to (6) above, which contains the rare earth-iron-nitrogen magnetic material in an amount of 1 to 99.999% by mass and the ceramic material in an amount of 0.001 to 99% by mass. For composite magnetic materials.
(8) The composite magnetic material for high frequencies according to (7) above, wherein the ceramic material is a powder having an average particle size of 1 nm or more and less than 1000 nm.
(9) Fe, Ni, Co, Fe-Ni alloy, Fe-Ni-Si alloy, Sendust, Fe-Si-Al based on the rare earth-iron-nitrogen magnetic material in an amount of 1 to 99.999% by mass. 0.001 to 99 mass of at least one selected from alloys, Fe-Cu-Nb-Si alloys, morphus alloys, magnetite, Ni-ferrite, Zn-ferrite, Mn-Zn ferrite, and Ni-Zn ferrite. The composite magnetic material for high frequency according to any one of (1) to (6) above, which is contained in%.
(10) The composite magnetic material for high frequency according to (9) above, wherein Fe is carbonyl iron powder.
(11) The composite magnetic material for high frequencies according to any one of (1) to (10) above, which is magnetically oriented.
(12) A high-frequency magnetic material resin containing the high-frequency composite magnetic material according to any one of (1) to (11) in an amount of 5 to 99.9% by mass and a resin of 0.1 to 95% by mass. Composite material.
(13) The high-frequency magnetic material resin composite material according to (12) above, wherein the resin contains a segment having a solubility parameter of 10 to 15.
(14) The high-frequency magnetic material resin composite material according to (12) or (13) above, wherein the resin is a polyamide ester ether resin.
(15) An electromagnetic wave absorbing material containing the high-frequency magnetic material according to any one of (1) to (11) above.
(16) An electromagnetic noise absorbing material containing the high-frequency magnetic material according to any one of (1) to (11) above.
(17) A material for RFID tags, which comprises the magnetic material for high frequencies according to any one of (1) to (11) above.
(18) A coil core for a wireless power feeding system, which comprises the high-frequency magnetic material according to any one of (1) to (11) above.
(19) The rare earth-iron-nitrogen magnetic material is obtained by heat-treating an alloy containing R component and Fe component as main components in a nitrided atmosphere containing ammonia gas or nitrogen gas in the range of 200 to 650 ° C. , The method for producing a high-frequency composite magnetic material according to (1) above.
(20) The rare earth-iron-nitrogen-based magnetic material obtained by the production method according to (19) above, or the rare earth-iron-nitrogen-based magnetic material obtained by further pulverizing the rare earth-iron-nitrogen-based magnetic material. The method for producing a composite magnetic material for high frequency according to (8) above, which is produced by mixing a magnetic material and a powdered ceramic material having an average particle size of 1 nm or more and less than 1000 nm.
(21) A rare earth-iron-nitrogen magnetic material obtained by the production method according to (19) or (20) above, or a composite magnetic material for high frequency produced by the production method according to (19) or (20) above. The high frequency according to (12) above, which is produced by kneading with a resin containing segments having solubility parameters 10 to 15 and being produced by at least one selected from compression molding, injection molding, and calendar molding. Magnetic material for resin Composite material manufacturing method.

According to the present invention, a composite magnetic material for high frequencies having high magnetic permeability and small eddy current loss, particularly functioning as an electromagnetic wave absorber in an ultrahigh frequency region (particularly in an ultrahigh frequency region of 10 GHz or more), or in a high frequency region (particularly 100 MHz). It is possible to provide a high frequency magnetic material that is suitably used for a high frequency composite magnetic material that functions as an electromagnetic wave amplification material in the following high frequency region).

Hereinafter, the present invention will be described in detail.
The main form of the "high-frequency composite magnetic material containing a rare earth-iron-nitrogen magnetic material" of the present invention is powder, and in the present application, this is also referred to as "high-frequency composite magnetic material powder". This high-frequency composite magnetic material powder is used for various purposes as a high-frequency composite magnetic material after adjusting its composition, particle size, and circularity, and adding components such as ceramics and resin as necessary. Be done. In composite magnetic materials for high frequencies, ferromagnetism is mainly carried out by rare earth-iron-nitrogen magnetic material components, but when ceramic materials and resins coexist between the material powders, a significant improvement in electrical resistivity is achieved. .. In addition, by introducing and adjusting nanoceramic materials and resins having a solubility parameter of 10 to 15, the isolated dispersion of rare earth-iron-nitrogen magnetic material powder is promoted, resulting in a large electrical resistivity. Improvement is achieved. In the present application, "nano" refers to a scale of 1 nm or more and less than 1000 nm unless otherwise specified.
By using these composite magnetic materials for high frequencies, an electromagnetic wave absorbing material used in a high frequency region of 0.005 to 100 GHz and an electromagnetic wave amplifying material used in a high frequency region of 5 to 100 MHz can be obtained with significantly reduced eddy current loss. Be done.

Hereinafter, the composition of the rare earth-iron-nitrogen magnetic material, its crystal structure, morphology, and magnetic anisotropy, the high-frequency composite magnetic material to which the ceramic material is added, and the components of the high-frequency magnetic material resin composite material will be described. In addition, methods for manufacturing these materials (particularly, a method for nitriding a rare earth-iron-based raw material alloy to obtain a rare earth-iron-nitrogen-based magnetic material, a method for adding a ceramic material and a method for magnetic field orientation, and a method for blending and molding a resin Method) will also be described.
Examples of the rare earth element (R) in the general formula (1) described in the above (2) of the present invention include Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er. At least one of Tm, Yb and Lu may be included. Therefore, a raw material in which two or more rare earth elements such as mischmetal and didymium are mixed may be used, but preferable rare earths are Y, La, Ce, Pr, Nd, Gd, Dy, Er, and Yb. More preferably, it is Y, Ce, Pr, Nd, Gd, Dy.
It is particularly preferable to contain Nd or Pr in an amount of 50 atomic% or more of the entire R component because a material having a significantly high magnetic permeability and the "maximum absorption energy coefficient" defined later can be obtained, and further, the oxidation resistance and cost are increased. From the balance, it is preferable to contain Nd or Pr in an amount of 70 atomic% or more.

A rare earth-iron-nitrogen magnetic material having a crystal structure of at least one selected from hexagonal crystals, rhombohedral crystals, and square crystals (particularly rhombic crystals or hexagonal crystals) (hereinafter, this material is referred to as "R". -Fe-N-based magnetic material ", and this" R "is also called" rare earth component "or" R component "), when Sm is contained as a rare earth component in an amount of 50 atomic% or more with respect to the entire rare earth component, a high frequency region The value of the relative permeability (imaginary and real terms of complex relative permeability) can be extremely low, less than 0.3, and when trying to utilize absorption using the natural resonance of nitrides, it exceeds 100 GHz. It may be limited to use in high frequency applications. Therefore, in view of the object of the present invention that positively utilizes in-plane magnetic anisotropy, it may not be preferable. From this point of view, it is preferable that the content of Sm in the rare earth component does not exceed 50 atomic% in the rare earth component. This is a rare earth-iron-nitrogen magnetic material having a crystal structure of at least one selected from hexagonal, rhombohedral, and square (particularly rhombohedral or hexagonal), which contains rare earth components. When sm, since the uniaxial anisotropy constant _{K u} is positive at or above room temperature, the crystal magnetic anisotropy is uniaxial material thereof, other Y, Ce, Pr, Nd, Gd, Tb, Dy, Ho, This is because in Er, Tm, Lu and the like, the uniaxial anisotropy constant _Ku becomes negative above room temperature, and these crystal magnetic anisotropies tend to be in-plane materials.
The rare earth element used here may have a purity that can be obtained by industrial production, and impurities that are unavoidably mixed in production, such as O, H, C, Al, Si, F, Na, Mg, Ca, Li, etc. It does not matter if it exists.

The content of the rare earth component (R component) in the "rare earth-iron-nitrogen-based magnetic material (R-Fe-N-based magnetic material)" in the present invention is preferably 3 to 30 atomic% in the magnetic material composition. .. When the R component is 3 atomic% or more, when the content is less than that, the soft magnetic metal phase containing a large amount of iron component is separated beyond the permissible amount even after casting and annealing of the mother alloy, and this kind of soft The magnetic metal phase has a "maximum absorption frequency" defined later in a low frequency region, reduces magnetic permeability, and is used as a magnetic material for high frequencies in a high frequency region (particularly, an ultrahigh frequency region), which is one of the objects of the present invention. It is preferable in order to avoid the problem of impairing the function of.
Further, it is preferable that the R component content is 30 atomic% or less in order to avoid the problem that the magnetic permeability and the magnetization decrease when the content is exceeded. A more preferable composition range of the R component is 5 to 20 atomic%.
Iron (Fe) is a basic component of the "rare earth-iron-nitrogen-based magnetic material (R-Fe-N-based magnetic material)" responsible for ferromagnetism in the present invention, and its content is 40 in the magnetic material composition. It is preferably atomic% or more. It is preferable that the iron component (Fe component) content is 40 atomic% or more in order to avoid the problem that the magnetic permeability and the magnetization become small when the content is less than that. Further, when the iron component (Fe component) content is 96 atomic% or less in the magnetic material composition, when the content is exceeded, the soft magnetic metal phase containing a large amount of Fe is separated, and the R component is insufficient. It is preferable in that it avoids the same problem as in the case (that is, when the R component content is less than 3 atomic%). When the composition range of the iron component (Fe component) is 50 to 85 atomic%, the material has a high magnetic permeability and is a well-balanced material in which the natural resonance frequency or the maximum absorption frequency is in a more preferable range. preferable.

In the "rare earth-iron-nitrogen-based magnetic material (R-Fe-N-based magnetic material)" in the present invention, 0.01 to 50 atomic% of the iron component (Fe component) is the following component (hereinafter, "M"). The composition can be replaced with "ingredients"). "M component" includes Co, Ni, B, Al, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Pd, Ag, Cd, In, Sn, Hf, Ta, W, It is at least one selected from Ru, Re, Os, Ir, Pt, Pb, Bi, alkali metals, and alkaline earth metals. By introducing the M component, not all of it is necessarily replaced with Fe and incorporated into the crystal structure, but the Curie point, magnetic permeability, and resonance frequency can be increased, and the oxidation resistance performance can be improved.
In the description of the present invention in the present application, when it is described as "iron component" or "Fe component", or in a formula such as "R-Fe-N system" or in the context of discussing the composition of magnetic material, "Fe" or When described as "iron", unless otherwise specified, 0.01 to 50 atomic% of iron (Fe), which is a basic component of "rare earth-iron-nitrogen-based magnetic material" in the high-frequency composite magnetic material of the present invention, is used. The composition replaced with the M component is also included. It is preferable to replace 0.01 to 50 atomic% of the iron component (Fe component) with the M component, but it is particularly preferable to replace 1 to 50 atomic% of the iron component (Fe component) with the M component.
When the substitution amount of the M component is 50 atomic% or less of the iron component (Fe component), if the substitution amount is exceeded, the above-mentioned effect on the increase in manufacturing cost is small and a gain cannot be obtained in terms of cost performance. This is preferable in order to avoid the problem that the magnetic characteristics become unstable. Further, setting the substitution amount of the M component to 0.01 atomic% or more of the iron component (Fe component) avoids the problem that the replacement effect is hardly observed when the substitution amount is less than the substitution amount. It is preferable to the above.
Further, since Co and Ni have a high effect on the oxidation resistance performance and Co can greatly improve the Curie point in addition, Co and Ni can be preferable components as the M component. In this case, it is particularly preferable to replace 2 to 20 atomic% of the iron component (Fe component) with these components.

The present invention is characterized by using a "rare earth-iron-nitrogen-based magnetic material" as a high-frequency composite magnetic material, and can be used in a high-frequency region, which is difficult when an oxide magnetic material or a metal-based magnetic material is used. It is a magnetic material that makes it possible. Then, in order to exhibit a particularly excellent "target function", the content of nitrogen (N), which is a basic component of the "rare earth-iron-nitrogen-based magnetic material" used in the present invention, is set to the magnetic material composition. It is desirable that the range is 1 to 30 atomic%. It is preferable that the content of the nitrogen (N) component is 30 atomic% or less in order to avoid the problem that the magnetic permeability is generally lowered when the content exceeds the content. Further, it is preferable to set the nitrogen (N) component to 1 atomic% or more in order to avoid the problem that the magnetic permeability in the high frequency region or the ultrahigh frequency region does not improve so much if the content is less than that.
The inclusion of nitrogen in the magnetic material used as the high-frequency composite magnetic material of the present invention is one of the important compositional features of the high-frequency composite magnetic material of the present invention, and the main effect of this is One is the increase in electrical resistivity. This is because when the eddy current loss becomes remarkable, the real number term of the complex relative permeability decreases, and the problem that large electromagnetic wave absorption due to natural resonance in the high frequency region or the ultrahigh frequency region is hindered can be solved.

In materials with similar magnetic permeability, the higher the electrical resistivity, the higher the critical frequency at which eddy currents are generated. Therefore, in the high-frequency composite magnetic material of the present invention, the electrical resistivity increases due to the inclusion of a predetermined amount of nitrogen in the magnetic material, which is only commensurate with the high natural resonance frequency originally possessed by the R-Fe-N-based magnetic material. The eddy current loss is not noticeable until it reaches the high frequency region of. Therefore, a high complex relative permeability real number term can be maintained up to the high frequency region including the ultrahigh frequency region, and the effect of natural resonance can be sufficiently exerted in the higher frequency region, so that the high frequency including the ultrahigh frequency region can be sufficiently exhibited. A high complex relative permeability imaginary term can be realized in the region.
Further, when used as a high-frequency amplification material at 5 to 100 MHz, if an eddy current loss occurs in that frequency region, the temperature of the material rises and the real number term of magnetic permeability becomes small, resulting in poor efficiency, which is preferable. Absent. From this point of view, in order to further improve the electrical resistance of the rare earth-iron-nitrogen magnetic material and to make it a high-frequency magnetic material that can be suitably used in the frequency region of 10 GHz or higher in addition to the ultra-high frequency region, It is more desirable to control the content of nitrogen (N), which is a basic component of the "rare earth-iron-nitrogen-based magnetic material" used in the present invention, in the "high nitride" range of 12 to 30 atomic%. From the viewpoint of simplification of the process, an annealing treatment after the nitriding process is not essential in the range of 16 to 25 atomic%, and the rare earth-iron-nitrogen magnetic material prepared in this range has a natural resonance. Especially high frequency and electrical resistivity.

The optimum nitrogen content varies depending on the intended use, the R—Fe composition ratio of the R—Fe—N magnetic material, the amount ratio of the subphase, the crystal structure, and the like. For example, when Nd _10.5 Fe _76.1 Ni _12.4 having a rhombohedral structure is selected as the raw material alloy, the optimum amount of nitrogen exists in the vicinity of 10 to 22 atomic%. The optimum amount of nitrogen at this time is the amount of nitrogen for which at least one of the oxidation resistance performance and the magnetic property or the electrical property of the material is optimum, although it differs depending on the purpose.

The "magnetic properties" referred to here are the magnetic permeability (μμ ₀ ), specific magnetic permeability (μ), complex magnetic permeability (μ _r μ ₀ ), complex relative magnetic permeability (μ _r ), and their real terms. (Μ'), imaginary term (μ ”) and absolute value (| μ _r |), complex relative permeability The maximum value (μ” _max ) of μ ”in any frequency region in the frequency dependence of the imaginary term and its frequency when (f _a: this frequency is referred to as "maximum absorption frequency"), 'the maximum value of (mu' mu at a given frequency domain in the frequency dependence of the complex relative magnetic permeability real term _max) and at that time its maximum when the frequency (f _t), the "product of a value and its frequency (f) (Fmyu certain frequency (f) the complex relative magnetic permeability imaginary term (mu)" when the) is referred to as "absorption energy coefficient" maximum energy absorption coefficient is a value (fμ _"max), the magnetization _(I s), the uniaxial magnetic anisotropy field or plane magnetic anisotropy field _{(H a, H a1, H} a2), magnetic anisotropy energy ( Absolute value of E _a ), magnetic anisotropy ratio (p / q: when a magnetic material is uniaxially magnetically oriented at an orientation magnetic field of 1.2 MA / m, the magnetization at an external magnetic field of 1.0 MA / m in the applied orientation magnetic field direction q, therewith the magnetization in the external magnetic field 1.0 MA / m in the vertical direction and p), the temperature change rate of the magnetic permeability, at least one of the natural resonant frequency of the external alternating magnetic field caused by such electromagnetic waves (f _r) Say one.

The "electrical characteristics" are the electric resistance (= volumetric resistance ρ), electric conductivity (σ), impedance (Z), inductance (L), capacitance (C), reactivity (R), permittivity ( ε ε ₀ ), relative permittivity (ε), complex permittivity (ε _r ε ₀ ), complex relative permittivity (ε _r ), its real term (ε'), imaginary term (ε ”) and absolute value (| ε” _r |), the loss term (ε _t = ε ”+ σ / ω in the complex relative permittivity, which is the combination of the dielectric loss and the conductivity loss, and this ε _t is called the electrical loss term. Ω is the angular frequency).
The above "magnetic characteristics" and "electrical characteristics" are collectively referred to as "electromagnetic characteristics". In general, a horizontal bar line (-) may be added above the symbols "μ" and "ε" that represent relative permeability and relative permittivity, but in the present application, the relative permeability is set to "μ" and The relative permittivity is expressed as "ε". The above magnetic permeability can be regarded as the absolute value of the complex magnetic permeability when f → 0, and the dielectric constant can be regarded as the absolute value of the complex permittivity when f → 0.

Further, the "permeability" or "dielectric constant" is obtained by multiplying the relative magnetic permeability or the relative permittivity by the magnetic permeability of the vacuum or the dielectric constant of the vacuum.
In the description of the present invention in the present application, for example, when the expression "high magnetic permeability" or "high relative magnetic permeability" agreeing with it, the magnetic permeability or specific magnetic permeability of the material in a static magnetic field is high. Not only that, the absolute value of complex magnetic permeability or complex relative permeability is high in an AC magnetic field such as when an electromagnetic wave is acting, and if the value of the complex relative permeability imaginary term is close to 0, the complex relative permeability is high. If the value of the magnetic permeability real number term is high, and conversely, if the value of the complex relative permeability real number term is close to 0, it means that the value of the complex relative permeability imaginary number term is high. Since the above relationship is the same for "dielectric constant" and "relative permittivity", "permittivity" and "relative permittivity" in the above description should be read as "permittivity" and "relative permittivity", respectively. If you do, you can understand it as it is.

Next, a state in which the magnetic characteristics or the electrical characteristics are optimal will be described.
The optimum magnetic or electrical properties are the real or imaginary terms of magnetic permeability and complex relative permeability in the high frequency region, magnetization, curry point, electrical resistance, permittivity, and real number terms of complex relative permittivity. Values such as the imaginary term or loss term are maximized, and the absolute values of the temperature change rate of magnetic permeability and magnetization, electrical conductivity, etc. are minimized. The magnetic anisotropy ratio, magnetic anisotropy magnetic field, magnetic anisotropy energy, etc., which are closely related to the natural resonance frequency, have values that cause natural resonance at a desired frequency or maximize the absorption of electromagnetic waves. The set state is called optimal.
Each composition of the R-Fe-N-based magnetic material in the present invention contains 3 to 30 atomic% of the R component (rare earth component), 40 to 96 atomic% of the Fe component (iron component), and 1 to 30 atomic% of the N component. It is the range of, and these are satisfied at the same time. Further, the R—Fe—N-based magnetic material obtained in the present invention may contain 0.01 to 10 atomic% of hydrogen (H) in the magnetic material composition.

When H is included in the above composition range, the oxidation resistance performance and the magnetic permeability are improved. A particularly preferable composition of the R-Fe-N-based magnetic material of the present invention is expressed by the general formula R _x Fe _(100-x-y-z) N _y H _z , where x, y, z are atomic%. , 3 ≦ x / (1-z / 100) ≦ 30, 1 ≦ y / (1-z / 100) ≦ 30, 0.01 ≦ z ≦ 10, so that these three equations hold at the same time. x, y, z are selected.
Further, depending on the production method, oxygen (O) may be contained in an amount of 0.1 to 20 atomic%. In this case, the stability of magnetic properties is improved, and a magnetic material having a high electrical resistivity can be obtained. Accordingly, further preferred compositions of the R-Fe-N based magnetic material of the present invention have the general formula _{R x Fe (100-x-} y-z-w) when expressed in _{N y H z O w, x} , y, z and w are atomic%, 3 ≦ x / {(1-z / 100) (1-w / 100)} ≦ 30, 1 ≦ y / {(1-z / 100) (1-w / 100) } ≤30, 0.01≤z / (1-w / 100) ≤10, 0.1≤w≤20, and x, y, z, w so that these four equations hold at the same time. To be elected. When this oxygen component is localized on the surface of the magnetic powder, the effect of improving the electrical resistivity is high. For this purpose, the powder surface is subjected to acid treatment, alkali treatment, heat treatment before and after nitriding and before and after fine powder adjustment. A method of adding various surface oxidation treatments including a coupling treatment is also effective.

In the present invention, 0.01 atomic% or more and less than 50 atomic% of the nitrogen (N) component of the rare earth-iron-nitrogen magnetic material (R-Fe-N magnetic material) is H, C, P, Si, S. It may be replaced with at least one of each element of. When the nitrogen (N) component is replaced by at least one of these elements, not all of them are replaced with the N component, and not all of them are replaced with the N component, depending on the type and amount of the element to be replaced. However, depending on the type and amount of substituted elements, it may bring about improvements in electromagnetic properties such as oxidation resistance, magnetic permeability, and dielectric constant, and when used in high-frequency magnetic resin composite materials. Has a better affinity with the resin component, and may be expected to improve its mechanical properties.
Substituting 0.01 atomic% or more of the nitrogen (N) component with at least one of the above elements avoids the problem that the above replacement effect is almost eliminated if the amount is less than the replacement amount. preferable. Further, substituting less than 50 atomic% in the nitrogen (N) component with at least one of the above elements hinders the effect of nitrogen on the improvement of electrical resistivity and the optimization of resonance frequency when the substitution amount is exceeded. It is preferable to avoid the problem of

In the description of the present invention in the present application, when it is described as "nitrogen component" or "N component", or in a formula such as "rare earth-iron-nitrogen-based magnetic material" or "R-Fe-N-based" or magnetic material. In the context of discussing composition, when "N" and "nitrogen" are used, nitrogen, which is the basic component of "rare earth-iron-nitrogen-based magnetic material" in the high-frequency composite magnetic material of the present invention, unless otherwise specified. It also includes a composition in which 0.01 atomic% or more and less than 50 atomic% of (N) is replaced with H, C, P, Si, and S.
The "rare earth-iron-nitrogen magnetic material" used in the present invention preferably contains a phase having a rhombic crystal, hexagonal crystal and tetragonal crystal (particularly rhombic crystal or hexagonal crystal) crystal structure. In the present invention, these crystal structures are formed, and a phase containing at least R (rare earth), Fe (iron), and N (nitrogen) is called a main phase, and the crystal structure is not formed or another crystal structure is formed. A phase having a composition is called a subphase. The subphase is a non-main phase that is intentionally or unintentionally generated in the process of producing a rare earth-iron-nitrogen (-hydrogen-oxygen) magnetic material from a rare earth-iron raw material. The components of the main phase may include O (oxygen) and / or H (hydrogen) in addition to R (rare earths), Fe (iron), and N (nitrogen).
As an example of a preferable main phase crystal structure, a rhombohedral crystal having a crystal structure similar to Th ₂ Zn ₁₇ or the like, or a hexagonal crystal having a crystal structure similar to Th ₂ Ni ₁₇ , TbCu ₇ , Ca Zn ₅ or the like. It is necessary to include at least one of them.
Among them, it is good electromagnetic characteristics and its stability to include a rhombohedral crystal phase having a crystal structure similar to Th ₂ Zn ₁₇ and a hexagonal crystal phase having a crystal structure similar to Th ₂ Ni ₁₇ as the main phase. It is particularly preferable to ensure the sex.

The R—Fe—N-based magnetic material may contain an R—Fe alloy raw material phase, a hydride phase, a decomposition phase containing Fe nanocrystals, an amorphous oxide phase, and the like as subphases, but the effects of the present invention are sufficiently sufficient. In order to exert the effect, the body integration rate of the subphase must be kept lower than the content of the main phase, so that the content of the main phase is 75% by volume with respect to the entire R-Fe-N magnetic material. It is extremely preferable to exceed it in practical use. In many cases, the main phase of an R-Fe-N-based magnetic material is obtained by invading nitrogen between the lattices of the R-Fe alloy, which is the main raw material phase, and expanding the crystal lattice, but the crystal structure is , Has almost the same symmetry as the main raw material phase.
The "volume fraction" referred to here is the ratio of the volume occupied by a certain component to the total volume including the voids of the magnetic material.
The "main raw material phase" referred to here is at least one kind (particularly,) selected from hexagonal crystals, rhombohedral crystals, and tetragonal crystals, which contains at least R (rare earth) and Fe and does not contain N. A phase having a crystal structure of rhombic crystal or hexagonal crystal) (Note that a phase having a composition or crystal structure other than that and containing no N is referred to as an "auxiliary raw material phase" in the present application). ..

With the expansion of the crystal lattice due to the intrusion of nitrogen, one or more of the above items of oxidation resistance or magnetic properties / electrical properties are improved, and the R-Fe-N-based magnetic material is practically suitable. Only after the introduction of nitrogen, it becomes a suitable magnetic material for high frequency, and exhibits electromagnetic characteristics completely different from those of conventional nitrogen-free R-Fe alloys and Fe.
For example, when Pr _10.5 Fe _89.5 having a rhombic structure is selected as the main raw material phase of the mother alloy of the R—Fe component, the electrical resistivity increases by introducing nitrogen, and the Curie point, Magnetic properties such as absolute values of magnetic permeability and magnetic anisotropy energy and oxidation resistance are improved.

The rare earth-iron-nitrogen magnetic material used in the present invention is preferably a material utilizing its in-plane magnetic anisotropy. The in-plane magnetic anisotropy material is a material that is energetically more stable when the magnetic moment is present on the c-plane due to the presence of the magnetic moment on the c-axis.
The Sm-Fe-N-based magnetic material having a rhombohedral crystal or hexagonal crystal structure is not an in-plane magnetic anisotropy material but a uniaxial magnetic anisotropy material, and is widely used as a magnet material. However, when an attempt is made to use a magnetic material of a uniaxial magnetic anisotropy material other than such an in-plane magnetic anisotropy material as a magnetic material for high frequency applications, it functions only in a high ultrahigh frequency region exceeding 100 GHz as described above. In many cases, the magnetic permeability in the ultra-high frequency region is small. In order to avoid such a problem, the content of the Sm-Fe-N-based magnetic material is preferably less than 50% by volume of the total magnetic material.

Also, like the Sm-Fe-N magnetic materials, known rare earth magnet materials such as Nd-Fe-B and Sm-Co, which are uniaxial magnetic anisotropy rather than in-plane magnetic anisotropy, also have high frequencies. It cannot be said that it is suitable as a magnetic material for use. The reason is that Nd-Fe-B-based and Sm-Co-based magnetic materials for magnets have low electrical resistance because they are metal-based magnetic materials in addition to having uniaxial magnetic anisotropy. This is because the magnetic permeability decreases in the high frequency region due to the eddy current loss.

When the present invention is a composite magnetic material for high frequency powder, the average particle size of the powder is 0.1 to 2000 μm, preferably 0.2 to 200 μm. Here, the "average particle size" refers to the median diameter obtained based on the volume equivalent diameter distribution curve obtained by a commonly used particle size distribution measuring device.
If the average particle size is less than 0.1 μm, ignitability also occurs, and the manufacturing process becomes complicated, such as handling the powder in a low oxidation atmosphere. Further, if it exceeds 2000 μm, it becomes difficult to produce a homogeneous nitride, and the material is inferior in absorption of electromagnetic waves at 5 MHz or higher.
Therefore, when the present invention is a composite magnetic material for high frequency powder, the average particle size of the powder is 0.1 to 2000 μm.
Further, if the average particle size is less than 0.2 μm, the magnetic permeability is significantly lowered and the magnetic powder is agglomerated significantly, and the magnetic characteristics originally possessed by the material cannot be sufficiently exhibited, which is not suitable for general industrial production. Since it is a region, it cannot be said that the particle size range is very appropriate, but even if it is less than 0.2 μm, it is thin because its oxidation resistance is overwhelmingly superior to that of a nitrogen-free metal-based high-frequency magnetic material. It has the advantage of being suitable for ultra-small special-purpose high-frequency magnetic materials. From this point of view, in the high-frequency composite magnetic material of the present invention, the lower limit of the average particle size is preferably 0.1 μm, which is less than 0.2 μm.
However, as described above, it is more preferable that the average particle size is 0.2 μm or more in order to avoid the above-mentioned problems that occur when the average particle size is less than this.
Further, it is more preferable that the average particle size is 200 μm or less in order to avoid the problem that the magnetic permeability in the high frequency region decreases when the average particle size is exceeded.
So long as more average particle size of 0.5 to 10 [mu] m, f _a is the material high magnetic permeability be in a high frequency region, the selective absorption ratio at least 0.1GHz is higher material preferable.
Further, when the average particle size is in the range of 10 to 200 μm, the value of the imaginary term of high magnetic permeability and magnetic permeability is low, so that it is preferable because it is an electromagnetic wave amplification material at 5 to 100 MHz.

When the rare earth-iron-nitrogen magnetic material constituting the high-frequency composite magnetic material of the present invention is a powder, the average particle size thereof is the powder when the present invention is a powder high-frequency composite magnetic material. In many cases, the particle size is slightly smaller than the average particle size (specifically, about 10 nm), and the lower limit thereof is 0.1 μm or more from the viewpoint of stability of magnetic properties. It can be considered that the upper limit value and the lower limit value are almost the same as the case of the high-frequency composite magnetic material which is the powder of. Therefore, even when the rare earth-iron-nitrogen magnetic material is a powder, the average particle size is 0.1 to 2000 μm as in the case of the high-frequency composite magnetic material which is the powder of the present invention. It may be considered that it is preferably 0.2 to 200 μm. The reason is also as described in the particle size range of the high frequency composite material of the present invention.
The circularity (here, the circularity is also referred to as “φ”) of the rare earth-iron-nitrogen magnetic material in the present invention is preferably 0.6 to 1.
Here, the circularity (φ) of the rare earth-iron-nitrogen magnetic material in the present invention is the cross section of the material powder (for example, the cut and polished surface of the material powder photographed by SEM) or the projection surface on one plane. When the area (for example, SEM image of the material powder) is S and the peripheral length thereof is L, it is defined as φ = 4πS / L ² . If there is a hole surrounded by a closed curve in the cross section, S is calculated including the area of that part. If the shape of the material cross section is circular, φ is 1.
If the circularity is 0.6 or more, the electrical insulation property is low, the loss due to the eddy current is large, and the problem of low magnetic permeability is avoided. This is especially important for ease of use in the ultra-high frequency region. Further, when the circularity is high, the cross section of the powder becomes a circle, and the probability that the powder is close to a sphere is high. In that case, for example, in a thin body having many flat parts or a powder material having a low circularity having many low curvature parts, the contact area between the powders becomes large and it is difficult to perform electrical insulation, whereas the circularity is high. In the case of powder, even if the degree of isolation and dispersion is low, the electrical insulation is high because of point contact. Therefore, the circularity is preferably 0.6 to 1. More preferably, it is 0.7 to 1, and in this case, the magnetic permeability is improved even in an ultra-high frequency region such as 10 GHz, and the value of the imaginary term of the complex relative magnetic permeability exceeds 1, for example.

The composite magnetic material for high frequency of the present invention includes Fe, Ni, Co, Fe—Ni alloy, Fe—Ni—Si alloy, Sendust, Fe—Si—Al alloy, Fe—Cu—Nb—Si alloy. , Metallic magnetic materials such as morphas alloys, garnet-type ferrites such as magnetite, Ni-ferrite, Zn-ferrite, Mn-Zn ferrite, and Ni-Zn ferrite, and oxides such as soft magnetic hexagonal magnetoplumbite ferrite. Based magnetic materials can be mixed.
When this mixed material is applied to an electromagnetic wave absorbing material, the frequency band that absorbs electromagnetic waves can be expanded from the high frequency region to the low frequency region, and even in the high frequency region, broad absorption characteristics can be imparted to absorb noise in a wide band. can do. In particular, when carbonyl iron having a particle size of 0.1 to 100 μm is used as Fe of the mixed material, a composite magnetic material for high frequencies having a good balance between a magnetic permeability of less than 1 GHz and a magnetic permeability of 1 GHz or more can be obtained. The reason why high properties can be obtained when carbonyl iron is mixed with rare earth-iron-nitrogen materials is that [1] carbonyl iron has a very high circularity of 0.7 to 1 and is excellent in electrical insulation. , [2] When powder is mixed with a rare earth-iron-nitrogen magnetic material, the sign of chargeability on the surface of the metal powder carbonyl iron and the nitride powder rare earth-iron-nitrogen material are different. It is easy to mix homogeneously.
When carbonyl iron is used as the magnetic material (mixing material) to be mixed with the rare earth-iron-nitrogen magnetic material in the high-frequency composite magnetic material of the present invention used at ultra-high frequency, the preferable average particle size of the carbonyl iron powder is used. The range is 1-10 μm.

In the high-frequency composite magnetic material of the present invention, a material to be mixed to be composited with a rare earth-iron-nitrogen magnetic material (that is, a magnetic material different from the rare earth-iron-nitrogen magnetic material, or a non-magnetic material (for example) , Non-magnetic ceramic material and / or resin))) is preferably 0.001 to 99% by mass based on the total magnetic material in the high-frequency composite magnetic material of the present invention. The ratio of 0.001% by mass or more is preferable in order to obtain the effect of adding the metal-based magnetic material or the oxide-based magnetic material used as the mixed material, and the content of 99% by mass or less is 99% by mass or less in the present invention. This is because it is preferable to obtain the effect on various electromagnetic properties of the rare earth-iron-nitrogen magnetic material. Therefore, for example, when a ceramic material is used as the mixed material in the high-frequency composite magnetic material of the present invention, the amount of the rare earth-iron-nitrogen-based magnetic material is 1 to 99.999% by mass, and the amount of the ceramic material. Is preferably 0.001 to 99% by mass.
In order to fully utilize the characteristics such as absorption of rare earth-iron-nitrogen magnetic materials in the ultra-high frequency region, the total magnetic amount of metal-based magnetic materials and oxide-based magnetic materials other than rare earth-iron-nitrogen magnetic materials The mass fraction with respect to the material is preferably 0.05 to 75% by mass, and in order to take advantage of the characteristics of the electrical characteristics of the rare earth-iron-nitrogen magnetic material, it is further set to 0.01 to 50% by mass. preferable. Therefore, in order to utilize both characteristics, it is preferably 0.05 to 50% by mass.

In the composite magnetic material for high frequency including the rare earth-iron-nitrogen magnetic material of the present invention or the magnetic material resin composite material thereof, the value of the imaginary term of the complex relative permittivity at 1 GHz or more, that is, the value of the electrical loss term. There are materials with a value of more than 10 and materials with a high value of more than 50, and the typical value of the electrical resistance of the rare earth-iron-nitrogen-based magnetic material itself is 200 to 8000 μΩcm, which is a nitrogen-free metal-based magnetic material. It has an appropriate size located in the middle of the oxide magnetic material. When an electronic circuit is used as an electromagnetic wave source, electromagnetic waves in the distant field (a section at a distance exceeding 1 / 2π of the wavelength from the electromagnetic wave source. A section that is not a distant field is called a near field) are equivalent to the magnetic wave H. Since the electric field E is also a sufficiently large electromagnetic wave, the rare earth-iron-nitrogen system composite of the present invention is also used in applications in an ultra-high frequency region such as absorption of noise exceeding 10 GHz and in applications such as an electromagnetic wave absorber for distant fields used in an anechoic chamber. The magnetic material is very preferably used because it is a magnetic material having a high dielectric constant. It is preferable to make full use of this feature even when the above-mentioned metal-based magnetic material or oxide-based magnetic material is blended.

Here, the rare earth-iron-nitrogen magnetic material of the present invention and / or the composite magnetic material for high frequency including the rare earth-iron-nitrogen magnetic material coated with the ferrite-based magnetic material described later is used as the material for the RFID tag. The case where it is applied to a high-frequency amplification material such as a coil core for a wireless power feeding system will be described.
Among these, in the use of RFID tag materials, the high-frequency composite magnetic material of the present invention is positioned in an effective portion (for example, the entire back surface of the antenna) for improving the signal strength transmitted and received by the RFID tag and the antenna on the reader. It is important to let them do it. As for the magnetic characteristics, in order to improve the signal sensitivity, the magnetic permeability is required to be higher than 1, more preferably higher than 2, in the frequency region in which the signal exists (for example, around 13.56 MHz, 0.85 to 1 GHz, etc.). To. At the same time, it is also important that both the value of the imaginary term of the complex relative permeability and the value of the imaginary term of the complex relative permittivity are almost 0 so as not to absorb the signal. The high frequency amplification material of the coil core for a wireless power supply system is required to have a magnetic permeability of more than 1, more preferably more than 2, in the frequency range of 5 to 100 MHz. The high-frequency magnetic material resin composite material of the present invention having such characteristics is disclosed as a specific embodiment of the present invention in the examples of the present application.

Next, the ceramic material used for the composite magnetic material of the present invention will be described.
As mentioned above, the electrical and magnetic properties of rare earth-iron-nitrogen magnetic materials are intermediate between those of metal materials and oxide materials, but the chemical properties of the surface of the magnetic materials are also intermediate between the two. Therefore, when the rare earth-iron-nitrogen magnetic material is mixed in powder form, it can be mixed with the rare earth-iron-nitrogen magnetic material by putting it in a container and shaking it (hereinafter, also referred to as "shaking"). The charged state of the powder surface of the metal material or the rare earth-iron-nitrogen magnetic material and the oxide material is divided into positive and negative, and can be easily mixed in a homogeneous state.
Therefore, it is preferable to use an oxide-based ceramic material for the purpose of electrically insulating the rare earth-iron-nitrogen magnetic material powder and reducing the eddy current loss.
In particular, if the oxide-based ceramic material is a nanopowder of less than 1 μm, a high-frequency composite magnetic material having a high filling rate and high resistance can be realized. In particular, rare earth-iron-nitrogen magnetic materials and nanooxide ceramic materials can be homogeneously mixed in a short time by a simple operation such as shaking, and after homogeneous mixing, various magnetic field moldings described later can be performed. As with the high-frequency resin composite magnetic material, there is an advantage that magnetic field orientation can be performed.
Typical oxide-based materials include silica, alumina, chromium oxide, zirconia, magnesia, and rare earth oxides, including rare earths and Fe, which are the basic components of rare earth-iron-nitrogen magnetic materials, as well as Co, Ni, and B. , Al, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, In, Hf, Ta, W, Ag, Mg, Si or an oxide containing at least one selected from Composite oxides are preferred. Fe oxide is also a ceramic material that can be used in the present invention unless the surface of the rare earth-iron-nitrogen magnetic material is completely covered.
As described above, as the ceramic material used for the composite magnetic material of the present invention, it is preferable to use a nanoceramic material from the viewpoint of the isolated dispersibility of the rare earth-iron-nitrogen magnetic material powder, and therefore, the average of 1 nm or more and less than 1000 nm. It is preferably a powder having a particle size. In the present invention, when describing a nanoceramic material, the case of silica having a diameter of 1 nm or more and 1000 nm or less may be described by adding nano in front of the material name such as “nanosilica”.

Next, the "high-frequency magnetic material resin composite material" of the present invention will be described.

Examples of materials that can be used as resin components of high-frequency magnetic material resin composite materials are shown below.
For example, polyamide resins such as 12-nylon, 6-nylon, 6,6-nylon, 4,6-nylon, 6,12-nylon, amorphous polyamide, semi-aromatic polyamide; polyethylene, polypropylene, chlorinated Polyethylene-based resins such as polyethylene; polyvinyl chloride-based resins such as polyvinyl chloride, polyvinylacetate, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer; acrylics such as ethylene-ethylacrylate copolymer and polymethyl methacrylate. Polyamide. Acrylonitrile-based resins such as polyacrylic nitrile and acrylic nitrile / butadiene / styrene copolymer; various polyurethane-based resins. Phosphor-based resins such as polytetrafluoroethylene; engineering of polyacetal, polycarbonate, polyimide, polysulfone, polybutylene terephthalate, polyarylate, polyphenylene oxide, polyether sulfone, polyphenylsulfide, polyamideimide, polyoxybenzylene, polyether ketone, etc. Synthetic resin called plastic; thermoplastic resin containing liquid crystal resin such as all aromatic polyester; conductive polymer such as polyacetylene; heat of epoxy resin, phenol resin, epoxy-modified polyester resin, silicone resin, thermosetting acrylic resin, etc. Curable resin; examples thereof include elastomers such as nitrile rubber, butadiene-styrene rubber, butyl rubber, nitrile rubber, urethane rubber, acrylic rubber, and polyamide elastomer.

The resin component of the high-frequency magnetic material resin composite material of the present invention is not limited to the above-exemplified resin, but when at least one of the above-exemplified resins is contained, the electric resistance is high. It can be a magnetic resin composite material having excellent impact resistance, flexibility and molding processability. The content of the resin component is preferably in the range of 0.1 to 95% by mass. It is preferable that the content of the resin component is 0.1% by mass or more in order to avoid the problem that the effect of the resin such as impact resistance is hardly exhibited if the content is less than the content, and 95% by mass. It is preferable that the content is less than% in order to avoid the problem that the magnetic permeability and the magnetization are extremely lowered when the content is exceeded, and the practicality as a magnetic material resin composite material for high frequency is poor.
In particular, when the components other than the resin material component are only rare earth-iron-nitrogen magnetic materials, the content of the resin component is further increased to 1 to 95% by mass because there is no effect of electrical insulation of the ceramic material part. May be preferable.
Further, in the case where the magnetic material component is only a rare earth-iron-nitrogen magnetic material, and in applications where high magnetic permeability and impact resistance are particularly required, the range is 2 to 90% by mass for the same reason as described above. Is more preferable, and most preferably in the range of 3 to 80% by mass.
Further, the content of the magnetic material component in the high-frequency magnetic material resin composite material of the present invention is preferably 5 to 99.9% by mass, more preferably 5 to 99% by mass, still more preferably 10 to 98% by mass. Most preferably, it is 20 to 97% by mass. If the content of the magnetic material component is 5% by mass or more, if it is less than that content, the magnetic permeability and magnetization will drop extremely, and there will be a problem that the practicality as a high-frequency magnetic material will be poor. It is preferable to avoid it, and it is preferable that the content is 99.9% by mass or less in order to avoid the problem that the effect of the resin such as impact resistance is hardly exhibited when the content is exceeded.
In the high-frequency magnetic material resin composite material of the present invention, most of the electromagnetic characteristics are borne by the rare earth-iron-nitrogen magnetic material constituting the high-frequency composite magnetic material used, and the present invention. High-frequency magnetic material Resin composite material has impact resistance, flexibility, and impact resistance when applied to high-frequency magnetic materials, electromagnetic noise absorbing materials, electromagnetic wave absorbing materials, RFID tag materials, coil cores for wireless power feeding systems, etc. It is intended to improve the practicality by imparting the performance utilizing the characteristics of the resin such as moldability and high electric resistance to the high-frequency composite magnetic material. Therefore, the high-frequency magnetic material resin composite material of the present invention is very suitable as long as it is a resin component that does not impair the performance of the high-frequency composite magnetic material used in the present invention and imparts "some original characteristics of the resin". It can be said that it is an ingredient.
The above-mentioned "some original characteristics of the resin" is not limited to the characteristics of the resin exemplified above, and includes the characteristics and performance of all known resins.
Further, by electrically insulating the rare earth-iron-nitrogen magnetic material used in the present invention with a resin component, it can be applied to applications other than the high frequency magnetic material. In particular, when Sm is limited to less than 50 atomic% as the rare earth component of the rare earth-iron-nitrogen magnetic material used in the present invention, for example,
i) A low magnetic permeability that is achieved by mixing the rare earth-iron-nitrogen magnetic material having a small particle size and a large particle size to increase the filling rate and maintaining electrical insulation with a resin. Use as a material for frequency,
ii) By using the rare earth-iron-nitrogen magnetic material having shape magnetic anisotropy and maintaining electrical insulation with a resin, it can be applied as a material for magnetic recording with increased magnetization.

A titanium-based or silicon-based coupling agent can be added to the high-frequency magnetic material resin composite material of the present invention.
Generally, when a large amount of titanium-based coupling agent is added, the flowability and molding processability are improved, and as a result, the blending amount of the magnetic powder can be increased, and when the magnetic field is oriented, the orientation is improved and the magnetic characteristics are improved. It will be an excellent material for. On the other hand, when a silicon-based coupling agent is used, the effect of increasing the mechanical strength can be obtained, but the flowability is generally deteriorated.
It is possible to mix and add in order to take advantage of both the titanium-based coupling agent and the silicon-based coupling agent.
It is also possible to add an aluminum-based, zirconium-based, chromium-based, or iron-based coupling agent in addition to the titanium-based or silicon-based coupling agent.
Further, the high-frequency magnetic material resin composite material of the present invention can be further blended with various lubricants, heat-resistant antiaging agents, and antioxidants.
The powder of the present invention, a magnetic resin composite material for high frequency, can be used as it is or mixed with other materials (lubricant, heat resistant antiaging agent, antioxidant, etc.) in the form of a compound (mixture consisting of a plurality of materials). In the case of powder, the particle size may be in a range that is easy to handle in each molding process, such as for calendar processing and injection molding processing, but in the present invention, the oxidation resistance and magnetic properties of the powder are stable. From the viewpoint of property, the lower limit of the particle size is preferably 0.1 μm or more, 0.2 μm or more in order to obtain a powder having more flowability, and 10 μm or more in order to obtain a powder having more excellent flowability. More preferred. The upper limit of the particle size is not particularly specified, but if it is too large, the magnetic properties of the molded product will be uneven, so it is preferably 5 cm or less. In particular, when the magnetic material resin composite material is 20 mm or less, the variation in magnetic characteristics after molding is further reduced, which is more preferable, and when it is 2 mm or less, excellent flowability is also imparted, which is further preferable.

In the high-frequency magnetic material resin composite magnetic material of the present invention, it is difficult to give magnetism to the resin serving as a matrix. Therefore, as in the ferrite-coated rare earth-iron-nitrogen material described in Patent Document 1, "electrical insulation / It does not have the function of increasing the magnetic permeability by "magnetic connection" and at the same time suppressing the eddy current loss.
However, when the resin contains segments having a solubility parameter (also referred to as SP value) of 10 to 15, the high-frequency magnetic material resin composite magnetic material of the present invention constitutes the high-frequency magnetic material composite magnetic material existing as a powder. (Hereinafter referred to as "magnetic powder") is isolated and dispersed, and the connection between the magnetic powders is broken by the resin that is the insulator. Among them, eddy current loss can be suppressed over frequencies in the ultra-high frequency region). Therefore, when the high-frequency magnetic material resin composite magnetic material of the present invention is applied as an electromagnetic wave amplification material such as a coil core for a wireless power feeding system of 5 to 100 MHz, the eddy current loss can be extremely reduced, and further, 10 GHz can be obtained. applying high-frequency magnetic material-resin composite magnetic material of the present invention as an electromagnetic absorbing material or an electromagnetic noise absorber material used in the ultra high frequency region exceeding the maximum absorption energy coefficient by increasing the maximum absorption frequency (f _a) (fμ " It is possible to prevent _max ) from being reduced by eddy currents. The reason is that the resin segment with high solubility parameters has a high affinity for rare earth-iron-nitrogen powder, so it is strongly bonded to the interface. It is expected that this is because the magnetic powders are separated from each other and isolated and dispersed.
Here, the "solubility parameter" is a measure of intermolecular force, and it is said that the closer the SP (Solubility Parameter) values of the two substances are, the more compatible they are. Theoretically, since it is calculated from the heat of vaporization of a unit volume of liquid, it is defined only by a solvent having a melting point, but the solubility parameter of the resin is also determined based on the solubility in a solvent having a known SP value. If the structure is known even for a resin having no literature value, the SP value can be obtained based on the Fedors estimation method, and it is possible to determine whether or not the resin is effective for the present invention by rounding off to the first decimal place. it can.

Examples of the resin segment having a solubility parameter (SP) of 10 to 15 include polyamide (SP value 13 to 14), ester (SP value 10 to 11), polyurethane (SP value 10) and the like. Even if segments such as low SP value, polyether (SP value 9), silicone rubber (SP value 7 to 8), and fluororubber (SP value 7 to 8) are contained by copolymerization or the like. Often, in this case, the flexibility of the magnetic resin composite material is imparted, and it is suitable for electromagnetic noise absorbing material applications where the function as an elastomer is required. Among them, when a polyamide ester ether elastomer obtained by copolymerizing a polyamide having an SP value of 13.6 and a polyether of 9.0 is used as a resin component, surface smoothness is excellent, isolated dispersion is achieved, and magnetic permeability is high in the ultrahigh frequency region. It is a magnetic resin composite material having a high imaginary term value and excellent flexibility and impact resistance. It is predicted that this is due to the fact that it contains ester bonds in addition to polyamide and polyether, and contains segments with various compatibility parameters. This is because it is considered that the ester bond plays a role of reasonably connecting the polyamide component bonded to the surface of the rare earth-iron-nitrogen magnetic material and the polyether component that is between the powders and imparts flexibility and the like.
When the solubility parameter (SP) of the segment is set to 13 to 14, the magnetic permeability is further improved, and the volume fraction of the rare earth-iron-nitrogen-based magnetic powder is within a wide range of 30 to 80% by volume. , The value of the imaginary term of the complex relative permeability in the ultra-high frequency region falls within the practical region, which is preferable.
As described above, in the high-frequency magnetic material resin composite magnetic material of the present invention, when a resin having an adjusted solubility parameter (SP) is used, the chemical properties of the surface act, so from this point of view, , As disclosed in Patent Document 1, it is better not to be completely coated with the ferrite material.

Next, the method for producing the magnetic material and the magnetic material resin composite material of the present invention will be described, but the present invention is not particularly limited thereto.
Further, as for the manufacturing method, a method for obtaining the "composite magnetic material for high frequency" of the present invention will be specifically exemplified.
In the description of the present invention in the present application, the "alloy consisting substantially of R component and Fe component" means an alloy containing R component and Fe component as main components, and Fe of this Fe component is another atom (Fe. Specifically, Co, Ni, B, Al, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, In, Hf, Ta, W, Ru, Pd, Re, Os, Ir. , Ag, Pt may be replaced with at least one selected from). In this application, this alloy is also referred to as "rare earth-iron (R-Fe) based alloy", "raw material alloy", or "matrix alloy".

(1) Preparation process of mother alloy As a method for producing an R-Fe-based alloy, (I) a high-frequency melting method in which each metal component of the R and Fe components is melted at a high frequency and cast into a mold or the like, (II) copper, etc. The arc melting method in which metal components are charged into the boat and melted by arc discharge, (III) the drop casting method in which the arc-melted molten metal is dropped into a water-cooled mold at once and rapidly cooled, and (IV) the high-frequency melted molten metal is rotated. Ultra-quenching method to obtain a ribbon-shaped alloy by dropping it on a copper roll, (V) Gas atomization method to obtain alloy powder by spraying molten metal melted at high frequency with gas, (VI) Powder of Fe component and / or M component Alternatively, the Fe-M alloy powder, the oxide powder of the R and / or M components, and the reducing agent are reacted at a high temperature to reduce the R or R and M components while adding the R or R and M components to Fe. R / D method of diffusing components and / or Fe-M alloy powder, (VII) Mechanical allowing method of reacting each metal component alone and / or alloy while finely pulverizing with a ball mill or the like, (VIII) Any of the above The alloy obtained by the above method is heated in a hydrogen atmosphere and once decomposed into an R and / or M hydride and an Fe component and / or an M component or an Fe-M alloy, and then as a low pressure at a high temperature. Any of the HDDR (Hydrogenesis Decomposition Decomposition) methods for recoupling and alloying while expelling hydrogen may be used.

When the high-frequency melting method and the arc melting method are used, the Fe-based component tends to precipitate when the alloy solidifies from the molten state, and the volume of the component having the maximum absorption frequency in the low frequency region even after the nitriding step is particularly performed. The fraction increases, causing a decrease in absorption in the high frequency and ultra high frequency regions. Therefore, an inert gas such as argon or helium is used for the purpose of eliminating the Fe-based component or increasing the crystal structure of rhombohedral, hexagonal or square crystals (particularly rhombic or hexagonal). It is effective to perform annealing in a gas containing at least one of hydrogen gases or in a vacuum in a temperature range of 200 to 1300 ° C., preferably in a range of 600 to 1185 ° C. The alloy produced by this method has a large crystal grain size, good crystallinity, and high magnetic permeability as compared with the case of using an ultra-quenching method or the like. Therefore, this alloy contains a large amount of a homogeneous main raw material phase, and is preferable as a mother alloy for obtaining the magnetic material of the present invention.

(2) Coarse pulverization and classification step It is also possible to directly nitrid the alloy ingot, R / D method or HDDR method alloy powder produced by the above method, but if the crystal particle size is larger than 2000 μm, the nitriding treatment time is long. Therefore, it is more efficient to perform coarse pulverization and then nitriding. Rough pulverization to 200 μm or less is particularly preferable because the nitriding efficiency is further improved.
Rough crushing is performed using a jaw crusher, a hammer, a stamp mill, a rotor mill, a pin mill, a coffee mill, or the like. Further, even if a crusher such as a ball mill or a jet mill is used, it is possible to prepare an alloy powder suitable for nitriding depending on the conditions. A method of occluding hydrogen in the mother alloy and then crushing it with the above crusher, or a method of repeatedly occluding and releasing hydrogen may be used.
Further, after coarse pulverization, it is also effective to adjust the particle size using a classifier such as a sieve, a vibration type or a sound wave type classifier, or a cyclone for more uniform nitriding. After coarse pulverization and classification, annealing in an inert gas or hydrogen can remove structural defects, which is effective in some cases. In the above, the preparation method of the powder raw material or the ingot raw material of the R—Fe based alloy in the production method of the present invention has been exemplified, but the nitriding shown below depends on the crystal particle size, the crushed particle size, the surface condition, etc. of these raw materials. There is a difference in the optimum conditions of.

(3) Nitrating / annealing step Nitrating is an R-Fe-based alloy powder obtained by using a gas containing a nitrogen source such as ammonia gas or nitrogen gas in the above steps (1) or (1) and (2). Alternatively, it is a step of bringing nitrogen into the crystal structure by contacting it with an ingot.
At this time, it is preferable to coexist hydrogen in the nitriding atmosphere gas because the nitriding efficiency is high and the nitriding can be performed while the crystal structure is stable. In addition, in order to control the reaction, an inert gas such as argon, helium, or neon may coexist. The most preferable nitriding atmosphere is a mixed gas of ammonia and hydrogen. In particular, if the partial pressure of ammonia is controlled in the range of 0.1 to 0.7, the nitriding efficiency is high and the rare earth-iron used in the present invention is used. -Nitrogen-based magnetic material (specifically, expressed by the general formula of R _x Fe _(100-xy) N _y , in which R is Y, Ce, Pr, Nd, Gd, Tb, Dy, Ho. , Er, Tm, Lu, and Sm, and when Sm is contained, Sm is less than 50 atomic% and x and y are atomic% with respect to the entire R component. , 3 ≦ x ≦ 30, 1 ≦ y ≦ 30) can be produced as a magnetic material covering the entire nitrogen content range.
The nitriding reaction can be controlled by gas composition, heating temperature, heat treatment time, and pressing force. Of these, the heating temperature varies depending on the composition of the mother alloy and the nitriding atmosphere, but is preferably selected in the range of 200 to 650 ° C. If the temperature is 200 ° C. or higher, the problem that the crystallization rate is very slow occurs if the temperature is lower than that temperature, and if the temperature is lower than 650 ° C., the main raw material phase is increased. It is preferable in order to avoid the problem that it cannot be decomposed and nitrided while maintaining the crystal structure of rhombohedral, hexagonal, and / or tetragonal (particularly rhombic or tetragonal). In order to increase the nitriding efficiency and the content of the main phase, a more preferable temperature range is 250 to 600 ° C.
Further, after nitriding, annealing in an inert gas and / or hydrogen gas is preferable in terms of improving magnetic properties. In particular, producing an R-Fe-N-based magnetic material in a highly nitrided region having a nitrogen content of 16 to 25 atomic% and then annealing in an atmosphere containing hydrogen gas improves magnetic permeability and magnetization. This is a very preferable method.
Examples of the nitriding / annealing apparatus include horizontal and vertical tube furnaces, rotary reactors, and closed reactors. Although the magnetic material of the present invention can be prepared in any of the devices, it is particularly preferable to use a rotary reactor in order to obtain a powder having a uniform nitrogen composition distribution.
The gas used for the reaction is an air flow method in which an air flow of 1 atm or more is sent to the reactor while keeping the gas composition constant, a filling method in which the gas is sealed in a container in a pressure range of 0.01 to 70 atm, or a combination thereof. Supply by etc.
The R-Fe-N magnetic material is produced for the first time through the above steps of nitriding and annealing. If this step is carried out using a gas that serves as a hydrogen source, it is possible to prepare an R-Fe-NH-based magnetic material.

(4) Fine pulverization step In the fine pulverization step, the above-mentioned R-Fe-N-based magnetic material or R-Fe-N-H-based magnetic material is pulverized to finer fine powder, or R-Fe-N- This is a step performed for the purpose of introducing the O component and the H component into the above-mentioned R—Fe—N magnetic material in order to obtain the HO magnetic material.
As a method of pulverization, in addition to the method mentioned in the above step (2), a dry / wet pulverizer such as a rotary ball mill, a vibrating ball mill, a planetary ball mill, a wet mill, a jet mill, a cutter mill, a pin mill, or an automatic mortar. And combinations thereof and the like are used. When introducing the O component or the H component, as a method of adjusting the introduction amount within the range of the present invention, a method of controlling the water content and the oxygen concentration in the finely pulverized atmosphere can be mentioned.
As a method for producing the rare earth-iron-nitrogen magnetic material of the present invention, a mother alloy having an R-Fe component composition is prepared by the method exemplified in the steps (1) or (1) and (2). Therefore, it is preferable to use the step of nitriding by the method shown in the step (3) and pulverizing shown in the step (4). In particular, the raw material alloy obtained in the step (1) or the raw material alloy obtained by crushing and classifying the raw material alloy by the method shown in the step (2) is subjected to an atmosphere containing at least one of an inert gas and a hydrogen gas. After heat treatment at 600 to 1300 ° C., nitriding is performed by heat treatment in the range of 200 to 650 ° C. in an atmosphere containing ammonia gas, and then nitriding results in deterioration of magnetic properties due to internal oxidation of the powder. A very small magnetic material can be obtained.

(5) Ceramic Material Mixing Step This step is a step of mixing the ceramic material with the rare earth-iron-nitrogen magnetic material obtained in (3) or (4). Ordinary mixers such as V-type mixers, tumblers, vibration mixers, shakers, drum mixers, locking mixers, shakers, rotary mixers, and the above-mentioned crushers and classifiers can be used. It is also possible to perform this step at the same time as the steps (1) to (3). A major feature of the present invention is that when nanoceramic powder is used as the ceramic material, not only the mixing becomes efficient but also the electromagnetic characteristics are improved.

(6) Orientation / Molding Process The high-frequency composite magnetic material of the present invention is used for various purposes such as molding a rare earth-iron-nitrogen magnetic material by adding other magnetic materials, ceramic materials, and resins. .. Above all, when the resin described above is blended, the magnetic material resin composite material for high frequency of the present invention is obtained. Further, when the magnetic material of the present invention is an anisotropic material, it is particularly recommended because a magnetic material having high magnetic properties or a magnetic material resin composite material is obtained by performing a magnetic field orientation operation at least once in this molding step. ..
As a method of solidifying a composite magnetic material obtained by adding other magnetic materials, ceramic materials, and resins to a rare earth-iron-nitrogen magnetic material and molding it, it is placed in a mold and cold-rolled. , It can be used as it is, or it can be subsequently formed by cold rolling, forging, shock wave compression molding, etc., but in most cases, it is sintered while being heat-treated at a temperature of 50 ° C. or higher. Perform molding. The heat treatment atmosphere is preferably a non-oxidizing atmosphere, and the heat treatment is preferably performed in a rare gas such as argon or helium, an inert gas such as nitrogen gas, or a reducing gas containing hydrogen gas. It is possible even in the atmosphere under the temperature condition of 500 ° C. or less. Further, it may be sintered under normal pressure or pressure, or may be sintered in vacuum.

This heat treatment can be performed at the same time as the compaction molding, and the pressure sintering method such as the hot press method, the HIP (hot isostatic press) method, and the SPS (discharge plasma sintering) method of the present invention can also be used. It is possible to mold magnetic materials. In order to make the pressurizing effect on the present invention remarkable, it is preferable that the pressing force in the heat sintering step is in the range of 0.0001 to 10 GPa. If the pressure is less than 0.0001 GPa, the effect of pressurization is poor and there is no difference between normal pressure sintering and electromagnetic characteristics. Therefore, pressure sintering reduces productivity, which is disadvantageous. Is preferable in avoiding the occurrence of. Further, it is preferable that the pressure is 10 GPa or less in order to avoid the problem that the pressurizing effect is saturated when the pressing force is exceeded and the productivity is only lowered even if the pressurizing effect is further increased.
In addition, a large pressurization imparts induced magnetic anisotropy to the magnetic material, which may deteriorate the inherent magnetic properties such as high magnetic permeability, or cause the maximum absorption frequency to deviate from the preferable range. Therefore, the preferred range of pressing force is 0.001 to 1 GPa, more preferably 0.01 to 0.1 GPa.

Furthermore, in many of the above methods, the surface of the magnetic material may be slightly decomposed and solidified. However, among the shock wave compression methods, the known underwater shock wave compression method is formed without decomposing the magnetic material. It is advantageous as a possible method.

The above step (3) or (3) → (4) or (3) → (5) or (3) → (4) → (5) When the rare earth-iron-nitrogen magnetic material powder and / or composite magnetic material powder obtained in the process is applied to a high-frequency magnetic material resin composite material, it is mixed with a thermosetting resin or a thermoplastic resin. It is molded by compression molding, kneading with a thermoplastic resin and then injection molding, and if necessary, further extrusion molding, roll molding, and / or calendar molding. At the time of the above mixing, a casting method in which a resin dissolved in a solvent is mixed with a magnetic powder and then the solvent is removed by vaporization or the like is also effective. For the above kneading, it is also effective to use a kneader or a single-screw or twin-screw extruder.

As for the type of sheet shape, for example, when applied to an electromagnetic noise absorbing sheet, a batch type sheet by compression molding having a thickness of 5 to 10000 μm, a width of 5 to 5000 mm, and a length of 0.005 to 1000 m, roll molding, calendar molding, etc. Roll-shaped sheet by.
When molding by the above method, if part or all of the steps are performed in a magnetic field, the magnetic particles may be magnetically oriented and the magnetic characteristics may be improved. There are three major methods of magnetic field orientation: uniaxial magnetic field orientation, rotating magnetic field orientation, and opposed magnetic field orientation.

Uniaxial magnetic field orientation means that a magnetic material or a magnetic material resin composite material that is in a movable state is usually subjected to a static magnetic field from the outside in an arbitrary direction to align the easy magnetization direction of the magnetic material with the external static magnetic field direction. Say. After that, usually, pressure is applied or the resin component is hardened to prepare a uniaxial magnetic field oriented molded product.
Rotating magnetic field orientation means that a composite magnetic material or magnetic material resin composite material that is in a movable state is placed in an external magnetic field that normally rotates in one plane, and the direction in which the magnetic material is difficult to magnetize is aligned in one direction. The method. The method of rotation is a method of rotating an external magnetic field, a method of rotating a magnetic material in a static magnetic field, a method of rotating neither an external magnetic field nor a magnetic material, but the strengths of a plurality of magnetic poles are synchronized and changed to make the magnetic field rotate. There is a method of forming a sequence that makes the magnetic material feel as if it were, and applying a magnetic field at any time, and a combination of the above methods. In extrusion molding and roll molding, two or more magnetic poles are arranged in the extrusion direction, and the strength or polarity of the magnetic field is changed so that the magnetic field that rotates when the composite magnetic material or magnetic material resin composite material passes is felt. The method of orientation is also broadly defined as rotational magnetic field orientation.

In the opposite magnetic pole orientation, the composite magnetic material or the magnetic material resin composite material is allowed to stand in an environment where the magnetic poles of the same poles face each other, or is moved by rotational or translational motion, or a combination thereof, so that the direction in which the magnetization is difficult is set. It is a method of aligning in the direction.
Uniaxial magnetic field orientation of high-frequency materials and high-frequency magnetic material resin composite materials with in-plane magnetic anisotropy improves magnetic permeability by 1 to 50%, and rotational magnetic field orientation and counter-magnetic field orientation of 1 to 200%. improves.
The magnetic field forming is preferably performed in a magnetic field of 8 kA / m or more, more preferably 80 kA / m or more, and most preferably 400 kA / m or more in order to sufficiently align the magnetic material with the magnetic field. The strength and time of the magnetic field required for magnetic field orientation are determined by the shape of the magnetic material powder, the viscosity of the matrix in the case of the magnetic material resin composite material, and the affinity with the magnetic material powder.

In general, the stronger the magnetic field is used, the shorter the orientation time is. Therefore, it is desirable to use a magnetic field of 400 kA / m or more for magnetic field orientation in roll molding or calendar molding in which the molding time is short and the viscosity of the matrix resin is high.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the present invention is not limited to these Examples and the like. For example, the present invention discloses in detail the electromagnetic characteristics in the range of 0.005 to 50 GHz according to Examples, and demonstrates that the magnetic material of the present invention has an excellent "function of interest". The materials of the invention are not limited to this range.

[Example 1]
A raw material alloy having an Nd _10.5 Fe _89.5 composition was prepared by annealing the ingot produced by the high-frequency melting method.
This raw material alloy was pulverized by a jaw crusher and then further pulverized by a cutter mill in an argon atmosphere to obtain a powder having an average particle size of about 60 μm. This Nd—Fe raw material alloy powder was charged into a horizontal tube furnace and heat-treated at 420 ° C. in a mixed air stream having a partial pressure of ammonia of 0.35 atm and a partial pressure of hydrogen gas of 0.65 atm for 1 hour to obtain an average particle size of about 30 μm. The composition was adjusted to Nd _9.1 Fe _77.3 N _13.2 . The magnetization value of this rare earth-iron-nitrogen magnetic material was 150 emu / g, and the magnetic anisotropy ratio was 0.86. Moreover, this magnetic material was a material of in-plane magnetic anisotropy.
Subsequently, the rare earth-iron-nitrogen-based magnetic material obtained above was jet-milled in an argon atmosphere to prepare an Nd-Fe-N-based magnetic material having an average particle size of about 2 μm. A polyamide ester ether resin having a polyamide segment having a solubility parameter value of 13.6 was blended therein in an amount of 9.9% by mass, kneaded at 150 ° C., further pulverized and classified to form a powder of 10 μm or more and 2 mm or less. A magnetic material resin composite material having a thickness of 1 mm was produced by forming the shape of the magnetic material resin composite material and then performing calendar molding. The density of the produced magnetic material resin composite material was 4.6, and the volume fraction of the magnetic material was 55% by volume.
The value of the real number term of the relative magnetic permeability at 0.005 to 100 MHz of the rare earth-iron-nitrogen magnetic material resin composite material obtained in this example is almost constant at 3.4 to 3.5, and is a complex relative permeability. The value of the imaginary term of magnetic permeability is as small as 0 to 0.7, and it can be used as a high-frequency amplification material in this region. The values of the real and imaginary terms of complex relative permeability at 10 GHz are 1.7 and 0.6, respectively, the value of the imaginary term of complex relative permeability at 50 GHz is 1.2, and the maximum absorption energy coefficient at that frequency. Reached 15 GHz. Therefore, it was found that the composite magnetic material for high frequency is suitable as an electromagnetic noise absorbing material in the region of 10 to 50 GHz. Further, the values of the real number term and the imaginary number term of the complex relative permittivity at 10 GHz are 25 and 4, respectively, and it was found that the material is also an electromagnetic wave absorbing material that is effective in absorbing electromagnetic waves from a distant field.
Was also measured in the three-terminal method, the volume resistivity of this sheet was 9 × 10 ⁷ Ωcm, quite magnetic material-resin composite material insulation was excellent good isolated dispersible, suitable high frequency magnetic material It turned out to be a resin composite material. As a result of analyzing this magnetic material resin composite material by an X-ray diffraction method, diffraction lines mainly showing rhombohedral crystals were observed.

[Example 2]
An Nd _9.1 Fe _77.3 N _13.2 series magnetic material having an average particle size of about 2 μm was prepared in the same manner as in Example 1.
Except for using a high-frequency composite magnetic material obtained by mixing 50% by mass of the Nd-Fe-N-based magnetic material obtained in this example and 50% by mass of carbonyl iron powder having an average particle size of 3.5 μm, the same as in Example 1. In the same manner, a magnetic material resin composite material having a thickness of 1 mm was produced. The density of the produced magnetic material resin composite material was 4.6, and the volume fraction of the magnetic material was 55% by volume.
The values of the real and imaginary terms of the complex relative magnetic permeability of the rare earth-iron-nitrogen magnetic material resin composite material obtained in this example at 10 GHz are 1.8 and 1.3, respectively, and the complex ratio at 50 GHz. The value of the imaginary term of magnetic permeability was 0.3. Compared with Example 1, the value of 10 GHz was very excellent, although it was inferior to the value of the imaginary term of the complex relative permeability of 50 GHz. Further, the values of the real number term and the imaginary number term of the complex relative permittivity at 10 GHz are 25 and 7, respectively, and it was found that the electromagnetic wave absorbing material is also effective in absorbing electromagnetic waves from a distant field.
Further, the volume resistivity of this sheet measured by the three-terminal method is 4 × 10 ⁹ Ωcm, which is a magnetic material resin composite material having extremely good insulation and excellent isolation and dispersibility, and is a suitable magnetic material for high frequency. It turned out to be a resin composite material.

[Comparative Example 1]
In Example 1, a sheet having a thickness of 1 mm was produced using soft magnetic ferrite powder, which is generally said to be suitable as a magnetic material for high frequencies, instead of the rare earth-iron-nitrogen magnetic material. The values of the real and imaginary terms of the complex relative permeability at 10 GHz were 0.5 and 0.4, respectively, which did not reach those of Examples 1 and 2, respectively. The value of the imaginary term of the complex relative permeability at 50 GHz was approximately 0 to 0.1, and it was found that the value could not be used in the ultra-high frequency region. The values of the real and imaginary terms of the complex relative permittivity at 10 GHz were 2 and 15, respectively.
Although both the magnetic permeability and the dielectric constant of the oxide magnetic material of Comparative Example 1 show values that can be used as a high-frequency magnetic material as compared with a metal material having a remarkable eddy current in the ultra-high frequency region, the present invention It was found that it was not as good as Examples 1 and 2.

[Examples 3 to 5]
Nd-Fe-N powders having an average particle size of 3 to 4 μm with various circularities were prepared in the same manner as in Example 1 except that the jet mill conditions (crushing pressure and amount of powder supplied) were changed.
The crushing pressure and the amount of powder supplied in each example were 1.0 MPa and 300 g / h in Example 3, 1.2 MPa and 300 g / h in Example 4, and 1.5 MPa and 100 g / h in Example 5, respectively. It was. The circularity of the obtained powder was 0.587 in Example 3, 0.761 in Example 4, and 0.737 in Example 5.
An epoxy resin was blended with these magnetic powders and cured at 150 ° C. to prepare a magnetic resin composite material of about 54% by volume.
The values of the circularity (φ) of the raw material powders of these examples and the imaginary term (μ ″) of the complex relative magnetic permeability at 10 GHz are as follows.
Example 3 φ = 0.587, μ ”= 0.78
Example 4 φ = 0.737, μ ”= 1.37
Example 5 φ = 0.761, μ ”= 1.54
It was found that when the circularity was lower than 0.6, the value of the imaginary term (μ ”) of the complex relative permeability was less than 1, and when it was higher than 0.7, it was higher than 1.

[Examples 6 to 9]
A solution prepared by dissolving various elastomer resins in a solvent was mixed with the rare earth-iron-nitrogen magnetic material prepared in Example 1, the solvent was cast, and then compression molding was performed by a hot press to prepare a magnetic resin composite material. .. The volume fraction of the magnetic powder at this time was adjusted to be about 30% by volume.
The measurement results of the imaginary term (μ ”) of the complex relative magnetic permeability at 10 GHz are shown below together with the solubility parameter with the higher solubility parameter in the various resin segments. The brackets shown are the solubility parameters (SP values).
Example 6 Polyamide (13.6) -polyether copolymer μ "= 0.72
Example 7 Polyester (10.7) -polyether copolymer μ "= 0.41
Example 8 Polyurethane (10.0) -polyether copolymer μ "= 0.38
Example 9 Silicon rubber (7.6) μ "= 0.12
Among various resins, the resin having a segment having a larger solubility parameter had a larger imaginary term (μ ”) of complex relative permeability at 10 GHz, and when the solubility parameter was 10 or more, it exceeded 0.3.

[Examples 10 to 12, Comparative Example 2]
The rare earth-iron-nitrogen-based magnetic material prepared in Example 1 was added with the nanopowder listed below, and the Pyrex glass container (Pyrex is a registered trademark) containing them was shaken 100 times to obtain the rare earth-. A composite magnetic material having a volume fraction of 70% by volume of the iron-nitrogen magnetic material was produced.
Subsequently, the value of the imaginary term (μ ") of the complex relative magnetic permeability at 10 GHz of the high frequency composite magnetic material obtained by compression molding this composite magnetic material with a pressing force of 1 GPa is shown below.
Example 10 Nanoferrite powder (particle size 5 to 50 nm) μ ”= 0.91
Example 11 Nanosilica powder (average particle size about 10 nm) μ ”= 1.73
Example 12 Nanoalumina powder (average particle size about 50 nm) μ ”= 1.58
The value of the imaginary term (μ ”) of the complex relative permeability at 10 GHz of the rare earth-iron-nitrogen magnetic material (Comparative Example 2) that was compression-molded without adding anything was 0.2.
From these results, even if only the rare earth-iron-nitrogen magnetic material is solidified as in Comparative Example 2, the absolute value of the complex relative permeability itself decreases due to the eddy current loss in the ultra-high frequency region. It does not have the excellent effect of the composite magnetic material according to Examples 10 to 12, which is a specific embodiment of the present invention, and shows better results than the metal-based magnetic material in which the magnetic permeability disappears. Even so, it was found that it does not become an excellent magnetic material for high frequency as in the present invention.

The present invention relates to transformers, heads, inductors, reactors, yokes, cores (magnetic cores), antennas, microwave elements, magnetic distortion elements, magnetic acoustics, etc. used in the high frequency region, which are mainly used in power equipment and information and communication related equipment. Magnetic materials used for magnetic materials such as Hall elements, magnetic sensors, current sensors, rotation sensors, electronic compasses, etc., such as elements and magnetic recording elements, especially wireless power supply (also called wireless power transmission or non-contact power transmission) Coil cores and antenna cores used in systems, as well as electromagnetic noise absorbing materials, magnetic materials such as electromagnetic wave absorbing materials and magnetic shielding materials that suppress obstacles due to unnecessary electromagnetic interference, and inductor elements such as noise removing inductors. The present invention relates to a composite magnetic material for high frequency, such as a material for use, a material for RFID (Radio Frequency Identification) tags, a material for noise filter, and a magnetic material for removing noise from a signal in a high frequency region.

Claims (21)

The crystal structure of the main phase contains at least one rare earth-iron-nitrogen magnetic material selected from hexagonal, rhombohedral, and tetragonal, and has an average particle size of 0.1 to 2000 μm. A composite magnetic material for high frequencies that is a powder. The composite magnetic material for high frequencies according to claim 1, wherein the rare earth-iron-nitrogen magnetic material is represented by the following general formula.
_{RxFe (100-x-y)} N y (1)
(However, in the formula, x and y are atomic%, 3 ≦ x ≦ 30, 1 ≦ y ≦ 30, and R is Y, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Lu. , At least one selected from Sm, and when Sm is contained, Sm is less than 50 atomic% with respect to the entire R component.) 0.01 to 50 atomic% of iron constituting the rare earth-iron-nitrogen magnetic material is Co, Ni, B, Al, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo. , In, Hf, Ta, W, Ru, Pd, Re, Os, Ir, Ag, Pt, which is replaced by at least one selected from, according to any one of claims 1 or 2. Composite magnetic material. Any of claims 1 to 3, wherein less than 50 atomic% of the nitrogen constituting the rare earth-iron-nitrogen magnetic material is replaced with at least one selected from H, C, P, Si, and S. The composite magnetic material for high frequency described in. The composite magnetic material for high frequency according to any one of claims 1 to 4, wherein the magnetocrystalline anisotropy of the rare earth-iron-nitrogen magnetic material is in-plane magnetic anisotropy. The composite magnetic material for high frequencies according to any one of claims 1 to 5, wherein the rare earth-iron-nitrogen magnetic material has a circularity of 0.6 to 1. The composite magnetic material for high frequency according to any one of claims 1 to 6, wherein the rare earth-iron-nitrogen-based magnetic material is contained in an amount of 1 to 99.999% by mass and a ceramic material is contained in an amount of 0.001 to 99% by mass. The composite magnetic material for high frequencies according to claim 7, wherein the ceramic material is a powder having an average particle size of 1 nm or more and less than 1000 nm. Fe, Ni, Co, Fe-Ni alloy, Fe-Ni-Si alloy, Sendust, Fe-Si-Al alloy, Fe in 1 to 99.999% by mass of the rare earth-iron-nitrogen magnetic material. Containing at least one selected from −Cu—Nb—Si based alloy, morphus alloy, magnetite, Ni—ferrite, Zn-ferrite, Mn—Zn ferrite, and Ni—Zn ferrite in 0.001 to 99% by mass. , The composite magnetic material for high frequency according to any one of claims 1 to 6. The composite magnetic material for high frequencies according to claim 9, wherein Fe is a carbonyl iron powder. The composite material for high frequencies according to any one of claims 1 to 10, which is magnetically oriented. A high-frequency magnetic material resin composite material containing the high-frequency composite magnetic material according to any one of claims 1 to 11 in an amount of 5 to 99.9% by mass and a resin in an amount of 0.1 to 95% by mass. The high-frequency magnetic material resin composite material according to claim 12, wherein the resin contains a segment having a solubility parameter of 10 to 15. The high-frequency magnetic material resin composite material according to claim 12 or 13, wherein the resin is a polyamide ester ether resin. An electromagnetic wave absorbing material including the high-frequency composite magnetic material according to any one of claims 1 to 11. An electromagnetic noise absorbing material including the high frequency composite magnetic material according to any one of claims 1 to 11. A material for RFID tags, which comprises the composite magnetic material for high frequencies according to any one of claims 1 to 11. A coil core for a wireless power supply system, comprising the composite magnetic material for high frequencies according to any one of claims 1-11. The rare earth-iron-nitrogen-based magnetic material is obtained by heat-treating an alloy containing R component and Fe component as main components in a nitrided atmosphere containing ammonia gas or nitrogen gas in the range of 200 to 650 ° C. The method for producing a composite magnetic material for high frequency according to 1. The rare earth-iron-nitrogen magnetic material obtained by the production method according to claim 19, or the rare earth-iron-nitrogen magnetic material obtained by further finely pulverizing the rare earth-iron-nitrogen magnetic material. The method for producing a high-frequency composite magnetic material according to claim 8, which is produced by mixing a powdered ceramic material having an average particle size of 1 nm or more and less than 1000 nm. The rare earth-iron-nitrogen-based magnetic material obtained by the production method according to claim 19 or 20 or the high-frequency composite magnetic material produced by the production method according to claim 19 or 20 is subjected to solubility parameters 10 to 15. The method for producing a magnetic material resin composite material for high frequency according to claim 12, which is produced by kneading with a resin containing segments and by at least one selected from compression molding, injection molding, and calendar molding.