Magnetic body, substrate equipped with magnetic body, electronic component, and method for manufacturing magnetic body

Abstract

The present invention addresses the first problem of providing: a magnetic material that is exceptional in any of moisture resistance, heat resistance, magnetic permeability, and hardness; and a method for manufacturing the magnetic material. The present invention addresses the second problem of providing a substrate equipped with a magnetic body, and an electronic component, in relation to the aforementioned magnetic body.　A magnetic body according to the present invention contains magnetic particles and a resin, wherein the metal atom content of the magnetic body is 35.0-50.0 atm% with respect to all atoms excluding hydrogen atoms and helium atoms in the magnetic body, the oxygen atom content of the magnetic body is 40.0-60.0 atm% with respect to all atoms other than hydrogen atoms and helium atoms in the magnetic body, and the carbon atom content of the magnetic body is 3.0-12.0 atm% with respect to all atoms excluding hydrogen atoms and helium atoms in the magnetic body.

Description

Magnetic body, substrate with magnetic body, electronic component, and method for manufacturing magnetic body

[0001] The present invention relates to a magnetic body, a substrate with a magnetic body, an electronic component, and a method for manufacturing a magnetic body.

[0002] As electronic devices become more compact and perform better, the integration density of electronic circuit boards is increasing. Under these circumstances, research is underway to develop substrates on which magnetic materials are mounted in any shape by using compositions containing magnetic particles.

[0003] For example, Patent Document 1 discloses "a soft magnetic powder composition characterized by comprising 80 to 93 wt % of a magnetic material as component (A) including at least one of sendust alloy powder, Ni-Zn ferrite powder, and Mn-Zn ferrite powder, and 7 to 20 wt % of a polymeric material as component (B)." Patent Document 1 also discloses a magnetic element manufactured by heating and kneading the soft magnetic powder composition, followed by processing and molding and cooling.

[0004] JP 2017-043749 A

[0005] Incidentally, magnetic materials are required to exhibit good magnetic properties even after undergoing a high-temperature, high-humidity test. The present inventors investigated the performance of a magnetic element (magnetic material) formed from the composition described in Patent Document 1 and found that the magnetic permeability fluctuated after the high-temperature, high-humidity test. This revealed that there is room for further improvement in moisture resistance. Further investigation into the performance of the magnetic material revealed that there is room for further improvement in heat resistance, as outgassing is likely to occur during reflow, and that there is also room for further improvement in magnetic permeability. Furthermore, magnetic materials are required to have excellent hardness as a basic performance.

[0006] Therefore, an object of the present invention is to provide a magnetic body that is excellent in all of moisture resistance, heat resistance, magnetic permeability, and hardness, and a method for manufacturing the same. Another object of the present invention is to provide a magnetic body-attached substrate and an electronic component related to the magnetic body.

[0007] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following configuration.

[0008] [1] A magnetic body comprising magnetic particles and a resin, wherein the content of metal atoms contained in the magnetic body is 35.0 to 50.0 atm% relative to all atoms in the magnetic body excluding hydrogen and helium atoms, the content of oxygen atoms contained in the magnetic body is 40.0 to 60.0 atm% relative to all atoms in the magnetic body excluding hydrogen and helium atoms, and the content of carbon atoms contained in the magnetic body is 3.0 to 12.0 atm% relative to all atoms in the magnetic body excluding hydrogen and helium atoms. [2] The magnetic body according to [1], wherein the resin comprises a cured product of an epoxy compound containing an aromatic ring. [3] The magnetic body according to [1] or [2], wherein the content of nitrogen atoms contained in the magnetic body is 0.05 to 2.0 atm% relative to all atoms in the magnetic body excluding hydrogen and helium atoms. [4] The magnetic body according to any of [1] to [3], wherein the metal atoms include Fe and Mn. [5] The magnetic body according to [4], wherein the metal atoms further include Co. [6] A substrate with a magnetic body, comprising a substrate having a hole, and the magnetic body according to any one of [1] to [5], disposed in the hole. [7] An electronic component, comprising the substrate with a magnetic body according to [6]. [8] A method for producing the magnetic body according to any one of [1] to [6], comprising: Step 1 of preheating a composition containing magnetic particles and a resin precursor or a resin at 100 to 170°C; and Step 2 of further heating the composition obtained in Step 1 at 180 to 220°C.

[0009] According to the present invention, it is possible to provide a magnetic body that is excellent in all of moisture resistance, heat resistance, magnetic permeability, and hardness, and a method for manufacturing the same. Furthermore, according to the present invention, it is possible to provide a magnetic body-attached substrate and an electronic component related to the magnetic body.

[0010] The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In the description of groups (atomic groups) in this specification, a notation that does not specify whether substituted or unsubstituted includes both unsubstituted and substituted groups, unless it is contrary to the spirit of the present invention. For example, the term "alkyl group" includes not only alkyl groups that do not have a substituent (unsubstituted alkyl groups) but also alkyl groups that have a substituent (substituted alkyl groups). Furthermore, the term "organic group" in this specification refers to a group containing at least one carbon atom.

[0011] In this specification, the word "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0012] In this specification, (meth)acrylate refers to acrylate and methacrylate, (meth)acrylic refers to acrylic and methacrylic, and (meth)acryloyl refers to acryloyl and methacryloyl.

[0013] In this specification, the "solid content" of a composition refers to the components that form a magnetic material. Therefore, when a composition contains a solvent (organic solvent, water, etc.), it refers to all components excluding the solvent. Note that liquid components are also considered to be solid content if they form a magnetic material.

[0014] In this specification, "boiling point" means the normal boiling point unless otherwise specified.

[0015] In this specification, the weight average molecular weight (Mw) is a polystyrene-equivalent value determined by gel permeation chromatography (GPC). The GPC method used in this specification is based on a method using an HLC-8020GPC (manufactured by Tosoh Corporation), TSKgel Super HZM-H, TSKgel Super HZ4000, or TSKgel Super HZ2000 (manufactured by Tosoh Corporation, 4.6 mm ID x 15 cm) as columns, and THF (tetrahydrofuran) as an eluent.

[0016] In addition, in this specification, unless otherwise specified, the substance corresponding to each component may be used alone or in combination of two or more. Here, when two or more substances are used in combination for each component, the content of that component refers to the total content of the substances used in combination, unless otherwise specified.

[0017] In this specification, the term "atm %" which indicates the content of each atom based on the atomic number is synonymous with "atomic %".

[0018] [Magnetic body] The magnetic body of the present invention is a magnetic body comprising magnetic particles and a resin, wherein the content of metal atoms contained in the magnetic body is 35.0 to 50.0 atm % relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, the content of oxygen atoms contained in the magnetic body is 40.0 to 60.0 atm % relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, and the content of carbon atoms contained in the magnetic body is 3.0 to 12.0 atm % relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms.

[0019] The magnetic body of the present invention having such a configuration is excellent in all of moisture resistance, heat resistance, magnetic permeability, and hardness. Although the details of the above-mentioned mechanism of action are not clear, the inventors speculate as follows: When the content of metal atoms contained in the magnetic body is less than 35.0 atm% relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, the magnetic body has poor magnetic permeability. On the other hand, when the content of metal atoms contained in the magnetic body is more than 50.0 atm% relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, the magnetic body has poor moisture resistance. Furthermore, when the content of oxygen atoms contained in the magnetic body is less than 40.0 atm% relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, the magnetic body has poor moisture resistance. On the other hand, when the content of oxygen atoms contained in the magnetic body is more than 60.0 atm% relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, the magnetic body has poor magnetic permeability. Furthermore, if the content of carbon atoms contained in the magnetic body is less than 3.0 atm% relative to all atoms in the magnetic body excluding hydrogen and helium atoms, the magnetic body will have poor hardness, while if the content of carbon atoms contained in the magnetic body is more than 12.0 atm% relative to all atoms in the magnetic body excluding hydrogen and helium atoms, the magnetic body will have poor heat resistance. The carbon atoms contained in the magnetic body are mainly derived from carbon atoms contained in the resin in the magnetic body, and the oxygen atoms and metal atoms contained in the magnetic body are mainly derived from oxygen atoms and metal atoms contained in the magnetic particles in the magnetic body. The magnetic body of the present invention is designed so that the respective contents (atm%) of metal atoms, oxygen atoms, and carbon atoms contained in the magnetic body fall within a predetermined range by adjusting the type and content of the resin and magnetic particles contained in the magnetic body, as well as the heating conditions during production of the magnetic body. In this specification, metal atoms also include semimetal atoms such as boron, silicon, germanium, arsenic, antimony, and tellurium.

[0020] The content of each atom in the magnetic material of the present invention can be detected by X-ray photoelectron spectroscopy (hereinafter also referred to as "XPS"). In this specification, XPS refers to a method for analyzing the content of each atom present on the surface of a measurement object (magnetic material) by irradiating the measurement object with X-rays and measuring the specific energy of the generated photoelectrons (content of each atom based on the atomic number: atomic %), and is intended to be an analysis method performed, for example, under the following conditions. Note that the measurement device and measurement conditions are not limited to these conditions as long as a similar analysis can be performed. Furthermore, due to the measurement principle of XPS, H element and element atoms cannot be detected, and H element and He element are not included in the measurement object elements. Apparatus: PHI Quantera-SXM (product name) apparatus manufactured by ULVAC-PHI, Inc. X-ray source: Monochromated Al Kα radiation (1486.6 eV, 25 W, 15 kV, beam diameter 200 μmφ) Measurement area: 200 μmφ Measurement conditions: Pass energy = 140 eV, step = 0.1 eV, number of accumulations 4 to 8 Ion beam: Ar-GCIB gun Measurement method: A magnetic material serving as a measurement sample is placed in the above apparatus, and ion sputtering is performed from one surface of the magnetic material to the other surface. Measurement is performed at a depth of approximately 50 nm from the surface of the magnetic material, with a photoelectron take-off angle of 45 degrees. Next, the peak area corresponding to each element is quantified, and the obtained peak area is converted to the atomic content (atomic %) of each atom based on the atomic number using the relative sensitivity coefficient.

[0021] In the following, the effect of the present invention may be said to be better when the magnetic body has better moisture resistance, better heat resistance, better magnetic permeability, and / or better hardness.

[0022] [Content of each atom contained in the magnetic body] The content of metal atoms contained in the magnetic body is 35.0 to 50.0 atm%, preferably 38.0 to 48.0 atm%, and more preferably 40.0 to 45.0 atm%, based on all atoms in the magnetic body excluding hydrogen atoms and helium atoms. As described above, metalloid atoms such as boron, silicon, germanium, arsenic, antimony, and tellurium are also included. The metal atoms contained in the magnetic body are not particularly limited, but in terms of superior magnetic permeability, it is preferable to contain at least one metal atom selected from the group consisting of Fe, Mn, Co, Zn, and Ni, more preferably Fe and at least one metal atom selected from Mn, Co, Zn, and Ni, and even more preferably Fe and at least one metal atom selected from Mn and Co. The metal atoms contained in the magnetic body preferably contain Fe and Mn because of their superior magnetic permeability, and most preferably contain Fe, Mn, and Co because of their superior magnetic permeability and moisture resistance. The metal atoms contained in the magnetic body also preferably contain Fe, at least one selected from Mn and Co, and Zn. The metal atoms contained in the magnetic body may also contain metal atoms other than at least one selected from the group consisting of Fe, Mn, Co, Zn, and Ni. Specific examples include Al, Si, Sc, Ti, V, Cu, Y, Mo, Rh, Pd, Ag, Sn, Sb, Te, Ba, Ta, W, Re, Au, Bi, La, Ce, Pr, Nd, Sr, Zr, Mn, Cr, Nb, Pb, Ca, and B. When the metal atoms contained in the magnetic material include metal atoms other than Fe, Mn, Co, Zn, and Ni, it is also preferable that the magnetic particles further contain one or more elements selected from the group consisting of Si, Cr, B, and Mo.

[0023] The lower limit of the content of at least one metal atom selected from the group consisting of Fe, Mn, Co, Zn, and Ni (when a plurality of metal atoms are contained, the total content thereof) is preferably 50.0 atm% or more, more preferably 70.0 atm% or more, and even more preferably 90.0 atm% or more, based on all metal atoms contained in the magnetic material. The upper limit is preferably 100 atm% or less, based on all metal atoms contained in the magnetic material.

[0024] The lower limit of the total content of metal atoms selected from the group consisting of Fe, Mn, Co, Zn, and Ni is preferably 30.0 atm% or more, more preferably 35.0 atm% or more, based on all atoms in the magnetic material excluding hydrogen atoms and helium atoms, and the upper limit is preferably 48.0 atm% or less, more preferably 46.0 atm% or less, and even more preferably 45.0 atm% or less, based on all atoms in the magnetic material excluding hydrogen atoms and helium atoms.

[0025] The lower limit of the Fe content is preferably 30.0 atm% or more based on all atoms in the magnetic material excluding hydrogen atoms and helium atoms, and the upper limit is preferably 48.0 atm% or less, more preferably 46.0 atm% or less, and even more preferably 45.0 atm% or less based on all atoms in the magnetic material excluding hydrogen atoms and helium atoms.

[0026] The lower limit of the Mn content is preferably 0.5 atm% or more, and more preferably 1.0 atm% or more, based on all atoms in the magnetic material excluding hydrogen atoms and helium atoms. The upper limit of the Mn content is preferably 10.0 atm% or less, and more preferably 6.0 atm% or less, based on all atoms in the magnetic material excluding hydrogen atoms and helium atoms.

[0027] The content of oxygen atoms contained in the magnetic material is 40.0 to 60.0 atm %, preferably 43.0 to 57.0 atm %, and more preferably 45.0 to 55.0 atm %, based on all atoms in the magnetic material excluding hydrogen atoms and helium atoms.

[0028] The content of carbon atoms contained in the magnetic material is 3.0 to 12.0 atm %, and preferably 5.0 to 9.0 atm %, based on all atoms in the magnetic material excluding hydrogen atoms and helium atoms.

[0029] The magnetic material may contain atoms other than metal atoms, oxygen atoms, and carbon atoms. Examples of such atoms include nitrogen atoms. The nitrogen atoms that the magnetic material may contain are preferably nitrogen atoms derived from nitrogen atoms contained in the resin. The content of nitrogen atoms contained in the magnetic material is preferably 0.05 to 2.0 atm%, more preferably 0.05 to 0.5 atm%, and even more preferably 0.07 to 0.3 atm%, based on all atoms in the magnetic material excluding hydrogen atoms and helium atoms.

[0030] [Characteristics of magnetic body] (Relative permeability) The relative permeability of the magnetic body at 60 MHz is preferably greater than 15, more preferably greater than 17, and even more preferably greater than 20. The upper limit is preferably 40 or less. The relative permeability of the magnetic body at 60 MHz can be measured using a high-frequency permeability measuring device (for example, "PER-01" manufactured by Keycom Co., Ltd.).

[0031] (Hardness) The Vickers hardness (HV) of the magnetic material is preferably more than 20 HV, more preferably more than 30 HV, and even more preferably more than 40 HV. The upper limit is preferably 80 HV or less. The Vickers hardness (HV) of the magnetic material is determined as the average value of the hardness values ​​at any 30 measurement points on the magnetic material using a hardness tester (for example, a "Micro Hardness Tester HM500" manufactured by Fisher Instruments).

[0032] (Thermal Weight Loss Rate) The thermal weight loss rate of the magnetic material is preferably less than 3%, more preferably less than 2%, and even more preferably less than 1%. The lower limit is preferably 0.1% or more. The thermal weight loss rate of the magnetic material is a value obtained by performing thermogravimetry using a thermogravimetric measuring device (for example, the "Q500" manufactured by TA Instruments) to determine the weight loss rate in a temperature range of 180 to 350°C, and deriving it based on the following mathematical formula (1). Formula (1) Thermal Weight Loss Rate (mass %) = {1 - (mass of sample at 350°C) / (mass of sample at 180°C)} x 100 The conditions for measuring the thermal weight loss rate are preferably a nitrogen atmosphere, a measurement temperature range of 23 to 500°C, and a heating rate of 10°C / min.

[0033] (Humidity Resistance) The change in relative permeability at 60 MHz (Δμ'), obtained by the following formula (2) after a magnetic material is left standing at a high temperature and humidity of 85°C and 85% for 500 hours, is preferably less than 0.1, more preferably less than 0.05, and even more preferably less than 0.01. The lower limit is preferably 0 or greater. Formula (2) Δμ'=1-μ'B / μ'A μ'A: relative permeability at 60 MHz before high temperature and humidity test μ'B: relative permeability at 60 MHz after high temperature and humidity test The relative permeability at 60 MHz of a magnetic material can be measured using a high frequency permeability measuring device (for example, "PER-01" manufactured by Keycom Corporation).

[0034] [Components Contained in Magnetic Material] The magnetic material contains magnetic particles and a resin. Each component will be described in detail below. <Magnetic Particles> The magnetic material contains magnetic particles. The magnetic particles usually contain metal atoms. In the magnetic particles, the metal atoms may be contained as an alloy containing the metal element, a metal oxide, a metal nitride, or a metal carbide.

[0035] The metal atoms are not particularly limited, but preferably contain at least one metal atom selected from the group consisting of Fe, Mn, Co, Zn, and Ni, in terms of superior magnetic permeability, more preferably contain Fe and at least one metal atom selected from Mn, Co, Zn, and Ni, and even more preferably contain Fe and at least one metal atom selected from Mn and Co. The metal atoms contained in the magnetic particles particularly preferably contain Fe and Mn, in terms of superior magnetic permeability, and most preferably contain Fe, Mn, and Co. The content of at least one metal atom selected from the group consisting of Fe, Mn, Co, Zn, and Ni (when multiple types are contained, the total content) is preferably 50 mass% or more, more preferably 60 mass% or more, and even more preferably 70 mass% or more, relative to the total mass of metal atoms in the magnetic particles. The upper limit of the content is not particularly limited, and is, for example, 100% by mass or less, preferably 98% by mass or less, and more preferably 95% by mass or less.

[0036] The magnetic particles may contain materials other than Fe, Mn, Co, Zn, and Ni, and specific examples thereof include Al, Si, S, Sc, Ti, V, Cu, Y, Mo, Rh, Pd, Ag, Sn, Sb, Te, Ba, Ta, W, Re, Au, Bi, La, Ce, Pr, Nd, P, Sr, Zr, Mn, Cr, Nb, Pb, Ca, B, C, N, and O. When the magnetic particles contain metal atoms other than Fe, Mn, Co, Zn, and Ni, it is preferable that the magnetic particles further contain one or more elements selected from the group consisting of Si, Cr, B, and Mo.

[0037] The shape of the magnetic particles is not particularly limited, and may be any of plate-like, elliptical, spherical, and irregular shapes, but spherical shapes are preferred in that the effects of the present invention are more excellent.

[0038] The magnetic particles are preferably ferrite particles. In addition to Fe, which constitutes iron oxide, the ferrite particles preferably contain at least one metal atom selected from the group consisting of Mn, Co, Zn, and Ni, and preferably contain at least one metal atom selected from the group consisting of Mn and Co. The ferrite particles may also contain materials other than Fe, Mn, Co, Zn, and Ni, and specific examples thereof include Al, Si, S, Sc, Ti, V, Cu, Y, Mo, Rh, Pd, Ag, Sn, Sb, Te, Ba, Ta, W, Re, Au, Bi, La, Ce, Pr, Nd, P, Sr, Zr, Cr, Nb, Pb, Ca, B, C, N, and O.

[0039] The volume average particle size of the ferrite particles is not particularly limited and is often 0.1 to 60 μm, and is preferably 5 to 55 μm, more preferably 10 to 50 μm, and even more preferably 20 to 50 μm, in terms of achieving better effects of the present invention. The volume average particle size of the ferrite particles is the so-called median diameter (D50), and can be determined based on a particle size distribution curve that represents the volume-based frequency distribution of the ferrite particles obtained using a laser diffraction / scattering particle size distribution analyzer (for example, the "LA960N" product manufactured by Horiba, Ltd.).

[0040] The crystal structure of the ferrite particles is not particularly limited, and examples thereof include spinel ferrite, hexagonal ferrite, and garnet ferrite, with spinel ferrite being preferred. Examples of spinel ferrite include Ni ferrite, Mn ferrite, Mn—Zn ferrite, Ni—Zn ferrite, Ni—Zn ferrite, Ni—Zn—Co ferrite, Mg—Zn ferrite, Cu—Zn ferrite, Ba—Ni ferrite, and Ba—Zn ferrite, with Mn ferrite, Mn—Zn ferrite, Ni—Zn ferrite, and Ni—Zn—Co ferrite being preferred.

[0041] A surface layer may be provided on at least a portion of the surface of the magnetic particle. By providing the magnetic particle with a surface layer, the magnetic particle can be endowed with a function according to the material of the surface layer. The surface layer may be an inorganic layer or an organic layer, and an organic layer is preferred.

[0042] As the inorganic layer-forming compound, metal oxides, metal nitrides, metal carbides, metal phosphate compounds, metal borate compounds, or silicate compounds (e.g., silicate esters such as tetraethyl orthosilicate, and silicates such as sodium silicate) are preferred because they can form a surface layer excellent in at least one of insulation, gas barrier properties, and chemical stability. Specific examples of elements contained in these compounds include Fe, Al, Ca, Mn, Zn, Mg, V, Cr, Y, Ba, Sr, Ge, Zr, Ti, Si, and rare earth elements. Materials constituting the inorganic layer obtained using the inorganic layer-forming compound include silicon oxide, germanium oxide, titanium oxide, aluminum oxide, zirconium oxide, and magnesium oxide, and the inorganic layer may be a layer containing two or more of these.

[0043] Examples of the organic layer-forming compound include acrylic monomers. Specific examples of the acrylic monomers include the compounds described in paragraphs 0022 to 0023 of JP 2019-067960 A. Examples of materials constituting the organic layer obtained using the organic layer-forming compound include acrylic resins.

[0044] The thickness of the surface layer is not particularly limited, but is preferably 3 to 1000 nm in order to allow the surface layer to exhibit its functions more effectively.

[0045] The magnetic particles may be used singly or in combination of two or more types. The content of the magnetic particles in the magnetic material (the total content when multiple types of magnetic particles are included) is preferably 93.0% by mass or more, more preferably 95.0% by mass or more, and even more preferably 96.0% by mass or more, relative to the mass of the magnetic material. The upper limit is preferably 99.0% by mass or less, more preferably 98.0% by mass or less, relative to the mass of the magnetic material.

[0046] The lower limit of the content of ferrite particles in the magnetic particles (the total content when multiple types of ferrite particles are included) is preferably 85.0 mass % or more, more preferably 90.0 mass % or more, still more preferably 95.0 mass % or more, and particularly preferably 98.0 mass % or more, based on the total mass of the magnetic particles. The upper limit is preferably 100 mass % or less.

[0047] The content of ferrite particles in the magnetic material (the total content when multiple types of ferrite particles are contained) is preferably 93.0% by mass or more, more preferably 95.0% by mass or more, and even more preferably 96.0% by mass or more, relative to the mass of the magnetic material. The upper limit is preferably 99.0% by mass or less, and more preferably 98.0% by mass or less, relative to the mass of the magnetic material.

[0048] <Resin> The magnetic material preferably further contains a resin. The resin is not particularly limited, and is preferably, for example, a resin formed by curing a thermosetting compound. The thermosetting compound is not particularly limited, and examples thereof include known thermosetting compounds, and epoxy compounds or oxetane compounds are preferred, with epoxy compounds containing an aromatic ring or oxetane compounds containing an aromatic ring being more preferred. Of the above thermosetting compounds, epoxy compounds containing an aromatic ring are more preferred because of their superior heat resistance. In other words, the magnetic material preferably contains a cured product of an epoxy compound containing an aromatic ring. The aromatic ring may be either an aromatic hydrocarbon ring or an aromatic heterocycle, but an aromatic hydrocarbon ring is preferred. The aromatic ring may be either a monocyclic or polycyclic ring. The number of aromatic rings in the epoxy compound and oxetane compound may be one or more, and may be, for example, 1 to 6.

[0049] The resin contained in the magnetic material may also contain resins that have been used as dispersants, thixotropes, etc. in magnetic compositions.

[0050] The resin may be used alone or in combination of two or more. The resin content (total content when multiple resins are included) in the magnetic material is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, relative to the mass of the magnetic material. The upper limit is preferably 20% by mass or less, more preferably 5.0% by mass or less, relative to the mass of the magnetic material.

[0051] <Other Components> The magnetic material may further contain other components in addition to the components described above. Examples of other components include known additives such as thixotropic agents, fillers such as silica, plasticizers, surfactants, and auxiliary agents (e.g., antifoaming agents, flame retardants, leveling agents, release promoters, antioxidants, fragrances, surface tension modifiers, and chain transfer agents).

[0052] [Magnetic Composition] The magnetic body can be formed from a magnetic composition (hereinafter also referred to as "composition"). The composition will be described below. <Magnetic Particles> The composition contains magnetic particles. The magnetic particles are synonymous with the magnetic particles described above, and the preferred embodiments are also the same. The content of the magnetic particles in the composition (the total content when multiple types of magnetic particles are contained) is preferably 93.0% by mass or more, more preferably 95.0% by mass or more, and even more preferably 96.0% by mass or more, based on the total solid content of the composition. The upper limit is preferably 99.0% by mass or less, more preferably 98.0% by mass or less, based on the total solid content of the composition.

[0053] The lower limit of the content of ferrite particles in the magnetic particles (the total content when multiple types of ferrite particles are included) is preferably 85.0 mass % or more, more preferably 90.0 mass % or more, still more preferably 95.0 mass % or more, and particularly preferably 98.0 mass % or more, based on the total mass of the magnetic particles. The upper limit is preferably 100 mass % or less.

[0054] The content of the ferrite particles in the composition (the total content when multiple types of ferrite particles are contained) is preferably 93.0 mass% or more, more preferably 95.0 mass% or more, and even more preferably 96.0 mass% or more, based on the total solid content of the composition, and the upper limit is preferably 99.0 mass% or less, more preferably 98.0 mass% or less, based on the total solid content of the composition.

[0055] <Binder Component> The composition preferably contains a binder component, which is typically one or more components selected from the group consisting of resins and resin precursors.

[0056] Examples of resin precursors include thermosetting compounds. Examples of thermosetting compounds include epoxy compounds and oxetane compounds. Epoxy compounds refer to compounds containing at least one epoxy group. Oxetane compounds refer to compounds containing at least one oxetanyl group. In epoxy compounds, the epoxy group may be fused with a cyclic group (such as an alicyclic group). The cyclic group fused with the epoxy group preferably has 5 to 15 carbon atoms. In the cyclic group, the portion other than the fused epoxy group may be monocyclic or polycyclic. One cyclic group may be fused with only one epoxy group, or two or more epoxy groups may be fused with one another. In oxetane compounds, the oxetanyl group may be fused with a cyclic group (such as an alicyclic group). The cyclic group fused with the oxetanyl group preferably has 5 to 15 carbon atoms. In the cyclic group, the portion other than the fused oxetanyl group may be a monocyclic or polycyclic ring. One cyclic group may have only one fused oxetanyl group, or two or more fused oxetanyl groups.

[0057] The epoxy compound and the oxetane compound may be any of a monomer, an oligomer, and a polymer. The epoxy compound is preferably a compound containing 2 to 10 epoxy groups. The oxetane compound is preferably a compound containing 2 to 10 oxetanyl groups. The molecular weight (or weight average molecular weight) of the epoxy compound and the oxetane compound is not particularly limited, but is preferably 2000 or less, for example. It is also preferable that the epoxy compound and the oxetane compound are liquid at 23°C.

[0058] Examples of epoxy compounds include epoxy resins that are glycidyl ethers of phenolic compounds (e.g., bisphenol A epoxy resins and bisphenol F epoxy resins), epoxy resins that are glycidyl ethers of various novolac resins (e.g., phenol novolac epoxy resins and cresol novolac epoxy resins), alicyclic epoxy resins, aliphatic epoxy resins, heterocyclic epoxy resins, glycidyl ester epoxy resins, glycidyl amine epoxy resins, epoxy resins obtained by glycidylating halogenated phenols, condensates of silicon compounds having epoxy groups with other silicon compounds, and copolymers of polymerizable unsaturated compounds having epoxy groups with other polymerizable unsaturated compounds. Examples of commercially available epoxy compounds include those described in paragraph

[0191] of JP 2012-155288 A, the contents of which are incorporated herein by reference. Commercially available epoxy compounds include Marproof G-0150M, G-0105SA, G-0130SP, G-0250SP, G-1005S, G-1005SA, G-1010S, G-2050M, G-01100, and G-01758 (epoxy group-containing polymers manufactured by NOF Corporation); ADEKA RESIN Other examples include EP-4000S, EP-4003S, EP-4010S, and EP-4011S (all manufactured by ADEKA Corporation); NC-2000, NC-3000, NC-7300, XD-1000, EPPN-501, and EPPN-502 (all manufactured by ADEKA Corporation); and JER1031S, JER871, and JER630 (manufactured by Mitsubishi Chemical Corporation).

[0059] Specific examples of bisphenol A epoxy resins and bisphenol F epoxy resins include ZX-1059 (manufactured by Nippon Steel Chemical & Material Co., Ltd.), 828US (manufactured by Mitsubishi Chemical Corporation), and ADEKA Resin EP-4000L (manufactured by ADEKA). Commercially available phenol novolac epoxy resins include JER-157S65, JER-152, JER-154, and JER-157S70 (all manufactured by Mitsubishi Chemical Corporation). Examples of polymerizable monomers or oligomers having two or more epoxy groups in the molecule include ZX1658GS (liquid 1,4-glycidylcyclohexane epoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd.), HP-4700 (naphthalene-type tetrafunctional epoxy resin, manufactured by DIC Corporation), and NC3000L (biphenyl-type epoxy resin, manufactured by Nippon Kayaku Co., Ltd.).

[0060] Examples of the epoxy compound include unsaturated compounds having an alicyclic epoxy group, such as those described in paragraph 0045 of JP-A No. 2009-265518.

[0061] Examples of the epoxy compound include monofunctional or polyfunctional glycidyl ether compounds, such as (poly)alkylene glycol diglycidyl ethers and glycidyl ether compounds of trivalent or higher polyhydric alcohols, such as glycerol, sorbitol, and (poly)glycerol.

[0062] The epoxy compound also includes a compound containing a caprolactone structure represented by the following formula (Z-1).

[0063]

[0064] In formula (Z-1), all of the six R's are groups represented by formula (Z-2E) below, or one to five of the six R's are groups represented by formula (Z-2E) below, and the remainder are groups represented by formula (Z-3E) below.

[0065]

[0066] In formula (Z-2E), m represents the number 1 or 2, X and Y each independently represent a hydrogen atom or a substituent (preferably an alkyl group, preferably having 1 to 3 carbon atoms), and * represents a bond. In formula (Z-3E), X and Y each independently represent a hydrogen atom or a substituent (preferably an alkyl group, preferably having 1 to 3 carbon atoms), and * represents a bond.

[0067] The epoxy compound also includes compounds represented by the following formula (Z-4) or (Z-5).

[0068]

[0069] In formulas (Z-4) and (Z-5), E is -((CH ２ ) ｙ CH ２ O)- or ((CH ２ ) ｙ CH (CH ３ )O)-, y represents an integer of 0 to 10, and X represents a group represented by the above formula (Z-3E) or a hydrogen atom. In formula (Z-4), the total number of groups represented by the above formula (Z-3E) is 2 to 4, m represents an integer of 0 to 10, and the total of all m's is an integer of 0 to 40. In formula (Z-5), the total number of groups represented by the above formula (Z-3E) is 2 to 6 (preferably 5 or 6), n represents an integer of 0 to 10, and the total of all n's is an integer of 0 to 60.

[0070] In formula (Z-4), m is preferably an integer of 0 to 6, more preferably an integer of 0 to 4. The sum of each m is preferably an integer of 2 to 40, more preferably an integer of 2 to 16, and even more preferably an integer of 4 to 8. In formula (Z-5), n is preferably an integer of 0 to 6, more preferably an integer of 0 to 4. The sum of each n is preferably an integer of 3 to 60, more preferably an integer of 3 to 24, and even more preferably an integer of 6 to 12. In formula (Z-4) or formula (Z-5), -((CH ２ ) ｙ CH ２ O)- or ((CH ２ ) ｙ CH (CH ３ )O)- is preferably in a form in which the terminal on the oxygen atom side is bonded to X.

[0071] Among the compounds represented by formula (Z-4) or formula (Z-5), pentaerythritol derivatives and / or dipentaerythritol derivatives are more preferred.

[0072] The epoxy compound also includes a compound having a structure in which N cyclic groups fused with epoxy groups are bonded via a linking group. N is an integer of 2 or more, preferably an integer of 2 to 6, and more preferably 2. The total number of atoms other than hydrogen atoms in the linking group is preferably 1 to 20, and more preferably 2 to 6. When N is 2, examples of the linking group include alkyleneoxycarbonyl groups.

[0073] The oxetanyl compound also includes a compound having a structure in which N cyclic groups fused with an oxetanyl group are bonded via a linking group. N is an integer of 2 or more, preferably an integer of 2 to 6, and more preferably 2. The total number of atoms other than hydrogen atoms in the linking group is preferably 1 to 20, and more preferably 2 to 6. When N is 2, examples of the linking group include an alkyleneoxycarbonyl group.

[0074] Specific examples of a polymer having an oxetanyl group in a side chain and a polymerizable monomer or oligomer having two or more oxetanyl groups in the molecule include Aron Oxetane OXT-121, OXT-221, OX-SQ, and PNOX (all manufactured by Toagosei Co., Ltd.).

[0075] Commercially available epoxy compounds and oxetanyl compounds include polyfunctional aliphatic glycidyl ether compounds such as Denacol EX-212L, EX-214L, EX-216L, EX-321L, and EX-850L (all manufactured by Nagase ChemteX Corporation). These are low-chlorine products, but non-low-chlorine products such as EX-212, EX-214, EX-216, EX-314, EX-321, EX-614, and EX-850 can also be used. In addition, Celloxide 2021P (manufactured by Daicel Corporation, a polyfunctional epoxy monomer) and EHPE 3150 (manufactured by Daicel Corporation, a polyfunctional epoxy / oxiranyl monomer) can also be used.

[0076] The composition may contain binder components other than the epoxy compound and the oxetane compound. Examples of other binder components include polyvinyl acetal resin, phenoxy resin, (meth)acrylic resin, ene-thiol resin, polycarbonate resin, polyether resin, polyarylate resin, polysulfone resin, polyethersulfone resin, polyphenylene resin, polyarylene ether phosphine oxide resin, polyimide resin, polyamideimide resin, polyolefin resin, cyclic olefin resin, polyester resin, and styrene resin. Commercially available polyvinyl acetal resins include, for example, "KS-1" manufactured by Sekisui Chemical Co., Ltd. Commercially available phenoxy resins include, for example, "YX7553BH30" (manufactured by Mitsubishi Chemical Corporation). Other binder components include the resins described in the examples of WO 2016 / 088645.

[0077] The binder component preferably contains at least one compound selected from the group consisting of an epoxy compound containing an aromatic ring and an oxetane compound containing an aromatic ring, and more preferably contains an epoxy compound containing an aromatic ring. The definition of an aromatic ring is as described above.

[0078] The content of the binder component (the total content when multiple binder components are included) is preferably 1.0 to 24 mass %, more preferably 1.0 to 15 mass %, even more preferably 1.0 to 12 mass %, particularly preferably 1.0 to 10 mass %, and most preferably 1.0 to 7 mass %, based on the total solid content of the composition.

[0079] <Dispersant> The composition preferably contains a dispersant. The dispersant is a resin that improves the dispersibility of magnetic particles and typically has functional groups (e.g., acid groups, basic groups, coordinating groups, and reactive functional groups) that can interact with the magnetic particles. Examples of acid groups include carboxylic acid groups, sulfonic acid groups, phosphate groups, and phenolic hydroxyl groups. Examples of basic groups include amino groups (groups in which one hydrogen atom has been removed from ammonia, primary amines, or secondary amines), imino groups, heterocycles containing N atoms, and amide groups. Examples of coordinating groups and reactive functional groups include acetylacetoxy groups, trialkoxysilyl groups, isocyanate groups, acid anhydrides, and acid chlorides. The dispersant is preferably a resin having an acidic group (in other words, an acidic dispersant) or a resin having a basic group (in other words, a basic dispersant), with a resin having a basic group (a basic dispersant) being more preferred.

[0080] When the dispersant has an acid group, the acid value of the dispersant is, for example, preferably 10 to 500 mgKOH / g, and more preferably 30 to 400 mgKOH / g.

[0081] The dispersant preferably contains a repeating unit containing a graft chain. That is, the dispersant is preferably a resin having a repeating unit containing a graft chain (hereinafter also referred to as "resin A"). In repeating units containing a graft chain, as the graft chain becomes longer, the steric repulsion effect increases, improving the dispersibility of magnetic particles. On the other hand, if the graft chain is too long, the adhesive force to the magnetic particles decreases, tending to reduce the dispersibility of the magnetic particles. For this reason, the graft chain preferably has a number of atoms excluding hydrogen atoms of 40 to 10,000, more preferably a number of atoms excluding hydrogen atoms of 50 to 2,000, and even more preferably a number of atoms excluding hydrogen atoms of 60 to 500. Here, the graft chain refers to the length from the base of the main chain (the atom bonded to the main chain in the group branching from the main chain) to the end of the group branching from the main chain.

[0082] Furthermore, the graft chain preferably contains a polymer structure, and examples of such polymer structures include a poly(meth)acrylate structure (e.g., a poly(meth)acrylic structure), a polyester structure, a polyurethane structure, a polyurea structure, a polyamide structure, and a polyether structure. In order to improve the interaction between the graft chain and the solvent and thereby enhance the dispersibility of the magnetic particles, the graft chain is preferably a graft chain containing at least one structure selected from the group consisting of a polyester structure, a polyether structure, and a poly(meth)acrylate structure, and more preferably a graft chain containing at least one of a polyester structure and a polyether structure.

[0083] Resin A may be a resin obtained using a macromonomer having a graft chain (a monomer having a polymer structure and bonding to a main chain to form a graft chain). The macromonomer having a graft chain (a monomer having a polymer structure and bonding to a main chain to form a graft chain) is not particularly limited, but a macromonomer having a reactive double bond group can be suitably used.

[0084] Commercially available macromonomers that correspond to the repeating units containing the graft chain and that are suitable for use in synthesizing Resin A include AA-6, AA-10, AB-6, AS-6, AN-6, AW-6, AA-714, AY-707, AY-714, AK-5, AK-30, and AK-32 (all trade names, manufactured by Toagosei Co., Ltd.), as well as Blemmer PP-100, Blemmer PP-500, Blemmer PP-800, Blemmer PP-1000, Blemmer 55-PET-800, Blemmer PME-4000, Blemmer PSE-400, Blemmer PSE-1300, and Blemmer 43PAPE-600B (all trade names, manufactured by NOF Corporation). Of these, AA-6, AA-10, AB-6, AS-6, AN-6, and Blenmer PME-4000 are preferred.

[0085] Resin A preferably contains at least one structure selected from the group consisting of polymethyl acrylate, polymethyl methacrylate, and cyclic or linear polyesters, more preferably at least one structure selected from the group consisting of polymethyl acrylate, polymethyl methacrylate, and linear polyesters, and even more preferably at least one structure selected from the group consisting of a polymethyl acrylate structure, a polymethyl methacrylate structure, a polycaprolactone structure, and a polyvalerolactone structure. Resin A may contain one of the above structures alone, or may contain a plurality of these structures. Here, the polycaprolactone structure refers to a structure containing a ring-opened ε-caprolactone structure as a repeating unit. The polyvalerolactone structure refers to a structure containing a ring-opened δ-valerolactone structure as a repeating unit.

[0086] When the composition contains resin A, the content of resin A is preferably 0.001 to 20.0 mass%, more preferably 0.01 to 15.0 mass%, still more preferably 0.05 to 10.0 mass%, and particularly preferably 0.05 to 5.0 mass%, relative to the total solid content of the composition.

[0087] A suitable embodiment of Resin A is a resin (hereinafter referred to as "Resin A1") containing a repeating unit containing a polyalkyleneimine structure and a polyester structure. The repeating unit containing a polyalkyleneimine structure and a polyester structure preferably contains a polyalkyleneimine structure in the main chain and a polyester structure as a graft chain.

[0088] The polyalkyleneimine structure is a polymer structure containing two or more identical or different alkyleneimine chains. Specific examples of the alkyleneimine chains include alkyleneimine chains represented by the following formula (4A) and formula (4B):

[0089]

[0090] In formula (4A), R Ｘ１ and R Ｘ２ each independently represents a hydrogen atom or an alkyl group. １represents an integer of 2 or more. *1 represents the bonding position with a polyester chain, an adjacent alkyleneimine chain, a hydrogen atom or a substituent.

[0091]

[0092] In formula (4B), R Ｘ３ and R Ｘ４ each independently represents a hydrogen atom or an alkyl group. ２ represents an integer of 2 or more. The alkyleneimine chain represented by formula (4B) is a polyester chain having an anionic group and the N ＋ The anionic groups contained in the polyester chains form salt bridges, thereby bonding the polymer to the polymer.

[0093] * in formula (4A) and formula (4B), and *2 in formula (4B) each independently represent a position at which the alkyleneimine chain is bonded to an adjacent alkyleneimine chain, or a hydrogen atom or a substituent. In particular, * in formula (4A) and formula (4B) preferably represents a position at which the alkyleneimine chain is bonded to an adjacent alkyleneimine chain.

[0094] R in formula (4A) Ｘ１ and R Ｘ２ , and R in formula (4B) Ｘ３ and R Ｘ４ each independently represents a hydrogen atom or an alkyl group. The alkyl group preferably has 1 to 6 carbon atoms, and more preferably has 1 to 3 carbon atoms. In formula (4A), R Ｘ１ and R Ｘ２ In formula (4B), R is preferably a hydrogen atom. Ｘ３ and R Ｘ４ are preferably all hydrogen atoms.

[0095] a in formula (4A) １ and a in formula (4B) ２ is not particularly limited as long as it is an integer of 2 or more. The upper limit is preferably 10 or less, more preferably 6 or less, even more preferably 4 or less, still more preferably 2 or 3, and particularly preferably 2.

[0096] In formula (4A) and formula (4B), * represents the bonding position to the adjacent alkyleneimine chain, or to a hydrogen atom or a substituent. Examples of the substituent include alkyl groups (e.g., alkyl groups having 1 to 6 carbon atoms). Furthermore, a polyester chain may be bonded as the substituent.

[0097] The alkyleneimine chain represented by formula (4A) is preferably linked to the polyester chain at the position *1 described above. Specifically, the carbonyl carbon in the polyester chain is preferably bonded at the position *1 described above. Examples of the polyester chain include polyester chains represented by the following formula (5A):

[0098]

[0099] When the alkyleneimine chain is an alkyleneimine chain represented by formula (4B), the polyester chain is anionic (preferably oxygen anion O － ) and the anionic group and N in formula (4B) ＋ It is preferable that the polyester chain forms a salt crosslinking group. An example of such a polyester chain is a polyester chain represented by the following formula (5B).

[0100]

[0101] L in formula (5A) Ｘ１ and L in formula (5B) Ｘ２ each independently represents a divalent linking group. The divalent linking group is preferably an alkylene group having 3 to 30 carbon atoms.

[0102] b in formula (5A) １１ and b in formula (5B) ２１ each independently represents an integer of 2 or more, preferably an integer of 6 or more, and the upper limit thereof is, for example, 200 or less.

[0103] b in formula (5A) １２ and b in formula (5B) ２２ each independently represents 0 or 1.

[0104] X in formula (5A) Ａ and X in formula (5B) Ｂeach independently represents a hydrogen atom or a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a polyalkyleneoxyalkyl group, and an aryl group.

[0105] The number of carbon atoms in the alkyl group (which may be linear, branched, or cyclic) and the alkyl group contained in the alkoxy group (which may be linear, branched, or cyclic) can be 1 to 30, and preferably 1 to 10. The alkyl group can further have a substituent, and examples of the substituent include a hydroxyl group and a halogen atom (examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom).

[0106] The polyalkyleneoxyalkyl group is R Ｘ６ (OR Ｘ７ ) ｐ (O) ｑ - is a substituent represented by R Ｘ６ represents an alkyl group, and R Ｘ７ represents an alkylene group, p represents an integer of 2 or more, and q represents 0 or 1. Ｘ６ The alkyl group represented by X Ａ In addition, R Ｘ７ The alkylene group represented by X Ａ Examples of suitable alkyl groups include groups in which one hydrogen atom has been removed from an alkyl group represented by the following formula: p is an integer of 2 or more, and the upper limit thereof is, for example, 10 or less, and preferably 5 or less.

[0107] Examples of the aryl group include aryl groups (which may be monocyclic or polycyclic) having 6 to 24 carbon atoms. The aryl group may further have a substituent, and examples of the substituent include an alkyl group, a halogen atom, and a cyano group.

[0108] The polyester chain is preferably a structure obtained by ring-opening a lactone such as ε-caprolactone, δ-caprolactone, β-propiolactone, γ-butyrolactone, δ-valerolactone, γ-valerolactone, enantholactone, β-butyrolactone, γ-hexanolactone, γ-octanolactone, δ-hexalanolactone, δ-octanolactone, δ-dodecanolactone, α-methyl-γ-butyrolactone, or lactide (which may be either the L- or D-form), and more preferably a structure obtained by ring-opening ε-caprolactone or δ-valerolactone.

[0109] The resin containing a repeating unit containing a polyalkyleneimine structure and a polyester structure can be synthesized according to the synthesis method described in Japanese Patent No. 5,923,557.

[0110] As a resin containing a repeating unit having a polyalkyleneimine structure and a polyester structure, reference can be made to the resin containing a repeating unit having a polyalkyleneimine structure and a polyester structure disclosed in Japanese Patent No. 5,923,557, the contents of which are incorporated herein by reference.

[0111] The weight average molecular weight of Resin A1 is not particularly limited, but is, for example, preferably 3,000 or more, more preferably 4,000 or more, even more preferably 5,000 or more, and particularly preferably 6,000 or more. The upper limit is, for example, preferably 300,000 or less, more preferably 200,000 or less, even more preferably 100,000 or less, and particularly preferably 50,000 or less.

[0112] Resins described in paragraphs

[0120] to

[0187] of WO 2022 / 202394 can also be suitably used as Resin A. Furthermore, examples of dispersants that can be used include the Marialim (registered trademark) SC series manufactured by NOF Corporation (e.g., SC-1015F, a polymer compound having a graft chain containing a polyoxyalkylene structure) and polyester polymer compounds (e.g., Hinoact T-6000 manufactured by Kawaken Fine Chemicals Co., Ltd.).

[0113] The dispersant may be used alone or in combination of two or more. When the composition contains a dispersant, the content of the dispersant (when multiple dispersants are contained, the total content) is preferably 0.001 to 20.0 mass%, more preferably 0.01 to 15.0 mass%, still more preferably 0.05 to 10.0 mass%, and particularly preferably 0.05 to 5.0 mass%, based on the total solid content of the composition.

[0114] <Thixotropic Agent> The composition may contain a thixotropic agent (rheology control agent). The thixotropic agent is a component that imparts thixotropic properties to the composition, i.e., high viscosity at low shear stress (shear rate) and low viscosity at high shear stress (shear rate). When the composition contains a thixotropic agent, the content of the thixotropic agent is preferably 0.01 to 10% by mass, more preferably 0.01 to 8.0% by mass, and even more preferably 0.01 to 6.0% by mass, based on the total solid content of the composition.

[0115] The thixotropic agent may be an organic thixotropic agent or an inorganic thixotropic agent, with the organic thixotropic agent being preferred.

[0116] (Organic thixotropic agent) When the composition contains an organic thixotropic agent, the content of the organic thixotropic agent is preferably 0.01 to 10 mass %, more preferably 0.01 to 8.0 mass %, and even more preferably 0.01 to 6.0 mass %, based on the total solid content of the composition. The organic thixotropic agents may be used alone or in combination of two or more.

[0117] Examples of organic thixotropic agents include compounds having one or more (preferably two or more) adsorption groups and further having a sterically repulsive structural group. The adsorption groups interact with the surface of the magnetic particles, causing the organic thixotropic agent to adsorb to the surface of the magnetic particles. Examples of the adsorption groups include acid groups, basic groups, and amide groups. Examples of acid groups include carboxy groups, phosphate groups, sulfo groups, phenolic hydroxyl groups, and their acid anhydride groups (such as acid anhydride groups of carboxy groups). Carboxy groups are preferred because they provide better effects of the present invention. Examples of basic groups include amino groups (groups in which one hydrogen atom has been removed from ammonia, primary amines, or secondary amines) and imino groups. Among these, the adsorption group is preferably a carboxy group or an amide group, and more preferably a carboxy group. The sterically repulsive structural group has a sterically bulky structure, which introduces steric hindrance into the magnetic particles to which the organic thixotropic agent has adsorbed, thereby maintaining an appropriate amount of space between the magnetic particles. As the steric repulsive structural group, for example, a chain group is preferred, a long-chain fatty acid group is more preferred, and a long-chain alkyl group is even more preferred. It is also preferred that the organic thixotropic agent has a hydrogen-bonding unit. The hydrogen-bonding unit is a partial structure that functions to build a hydrogen-bonding network between organic thixotropic agents and between organic thixotropic agents and other components. The organic thixotropic agent that contributes to the formation of the network may or may not be adsorbed to the surface of the magnetic particles. The hydrogen-bonding unit may be the same as or different from the above-mentioned adsorption group. When the hydrogen-bonding unit is the same as the above-mentioned adsorption group, a portion of the adsorption group bonds to the surface of the magnetic particles, and the other portion functions as a hydrogen-bonding unit. A carboxy group or an amide group is preferred as the hydrogen-bonding unit. A carboxy group as a hydrogen-bonding unit is preferred because it is easily incorporated into the curing reaction of the binder component, and an amide group is preferred because it provides better stability over time of the composition.

[0118] When the organic thixotropic agent is a resin, the resin organic thixotropic agent may or may not have a repeating unit containing a graft chain that can be contained in the dispersant described above. When the resin organic thixotropic agent is substantially free of a repeating unit containing a graft chain that can be contained in the dispersant described above, the content of the repeating unit containing the graft chain described above relative to the total mass of the resin organic thixotropic agent is preferably less than 2% by mass, more preferably 1% by mass or less, and even more preferably less than 0.1% by mass. The lower limit is 0% by mass or more.

[0119] The organic thixotropic agent is preferably one or more selected from the group consisting of polycarboxylic acids (compounds having two or more carboxy groups), polycarboxylic anhydrides (compounds having two or more acid anhydride groups formed by carboxy groups), and amide wax. These may be resins or non-resins. Furthermore, these may correspond to aggregation control agents and / or aggregation dispersants, which will be described later.

[0120] Examples of organic thixotropic agents include modified urea, urea-modified polyamide, fatty acid amide, polyurethane, polyamide amide, polymeric urea derivative, and its salt (such as carboxylate). Modified urea is a reaction product of an isocyanate monomer or its adduct with an organic amine. Modified urea is modified with polyoxyalkylene polyol (such as polyoxyethylene polyol or polyoxypropylene polyol) and / or alkyd chain. Urea-modified polyamide is, for example, a compound containing a urea bond and a compound having a medium-polarity group or a low-polarity group introduced at the end. Examples of the medium-polarity group or low-polarity group include polyoxyalkylene polyol (such as polyoxyethylene polyol or polyoxypropylene polyol) and alkyd chain. Fatty acid amide is a compound having a long-chain fatty acid group and an amide group in the molecule. These may be resins or other non-resins. These may also correspond to aggregation control agents and / or aggregation dispersants, which will be described later.

[0121] The molecular weight of the organic thixotropic agent (weight average molecular weight if the agent has a molecular weight distribution) is preferably in the range of 200 to 50,000. If the organic thixotropic agent has an acid value, the acid value is preferably 5 to 400 mg KOH / g. If the organic thixotropic agent has an amine acid value, the amine value is preferably 5 to 300 mg KOH / g.

[0122] Aggregation Control Agents Organic thixotropic agents include aggregation control agents. The aggregation control agent may be a resin or a non-resin material. The aggregation control agent functions to bind relatively dense aggregates such as magnetic particles, and further disperse binder components in the composition to form bulky aggregates. When the composition contains an aggregation control agent, the magnetic particles in the composition are prevented from hard caking, and bulkier aggregates are formed, which can improve redispersibility.

[0123] Examples of the aggregation control agent include cellulose derivatives, such as carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, hydroxypropylethyl cellulose, and salts thereof.

[0124] When the composition contains an aggregation control agent, the content of the aggregation control agent is preferably 0.01 to 10 mass %, more preferably 0.01 to 8.0 mass %, and even more preferably 0.01 to 6.0 mass %, based on the total solid content of the composition.

[0125] Agglomerating dispersants are also included as organic thixotropic agents. The agglomerating dispersant may be a resin or a non-resin material. Agglomerating dispersants adsorb to the surfaces of magnetic particles, separating the magnetic particles from one another, while maintaining a certain distance between the magnetic particles through interactions between the dispersants, thereby preventing the magnetic particles from agglomerating directly with one another. As a result, agglomeration of the magnetic particles is suppressed, and even if agglomerates are formed, the agglomerates are formed with a relatively low density. Furthermore, by dispersing a binder component in the composition, bulky agglomerates can be formed, which can improve redispersibility.

[0126] As the flocculating dispersant, alkylolammonium salts of polybasic acids are preferred. The polybasic acid may have two or more acid groups, and examples thereof include acidic polymers containing repeating units having acid groups (such as polyacrylic acid, polymethacrylic acid, polyvinylsulfonic acid, and polyphosphoric acid). Other examples of polybasic acids include polymers obtained by polymerizing unsaturated fatty acids such as crotonic acid. Alkylolammonium salts of polybasic acids can be obtained by reacting these polybasic acids with alkylolammonium. The salts obtained by such reactions usually contain the following partial structure: -C(=O)-N(-R １ ) (-R ２ —OH) where R １ is an alkyl group, R ２ is an alkylene group. As the alkylol ammonium salt of a polybasic acid, a polymer containing a plurality of the above partial structures is preferred. When the alkylol ammonium salt of a polybasic acid is a polymer, the weight average molecular weight is preferably 1,000 to 100,000, and more preferably 5,000 to 20,000. The polymer of the alkylol ammonium salt of a polybasic acid bonds to the surface of the magnetic particles and also forms hydrogen bonds with other aggregating dispersant molecules, allowing the main chain structure of the polymer to penetrate between the magnetic particles and separate the magnetic particles.

[0127] One preferred embodiment of the flocculating dispersant is amide wax, which is a dehydration condensation product of (a) saturated aliphatic monocarboxylic acids and hydroxyl group-containing aliphatic monocarboxylic acids, and (b) at least one of polybasic acids, and (c) at least one of diamines and tetraamines. The above (a) to (c) are preferably used in a molar ratio of (a):(b):(c)=1-3:0-5:1-6.

[0128] The saturated aliphatic monocarboxylic acids preferably have 12 to 22 carbon atoms. Specific examples include lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachidic acid, and behenic acid. The hydroxy group-containing aliphatic monocarboxylic acids preferably have 12 to 22 carbon atoms. Specific examples include 12-hydroxystearic acid and dihydroxystearic acid. These saturated aliphatic monocarboxylic acids and hydroxy group-containing aliphatic monocarboxylic acids may be used alone or in combination.

[0129] The polybasic acids are preferably dibasic or higher carboxylic acids having 2 to 12 carbon atoms, and more preferably dicarboxylic acids. Examples of such dicarboxylic acids include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, and 1,12-dodecanedicarboxylic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; and alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and cyclohexylsuccinic acid. These polybasic acids may be used alone or in combination.

[0130] The diamines preferably have 2 to 14 carbon atoms. Specific examples include ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, hexamethylenediamine, metaxylenediamine, tolylenediamine, paraxylenediamine, phenylenediamine, isophoronediamine, 1,10-decanediamine, 1,12-dodecanediamine, 4,4-diaminodicyclohexylmethane, and 4,4-diaminodiphenylmethane. The tetraamines preferably have 2 to 14 carbon atoms. Specific examples include butane-1,1,4,4-tetraamine and pyrimidine-2,4,5,6-tetraamine. These diamines and tetraamines may be used alone or in combination.

[0131] The amounts of diamines and tetraamines are adjusted according to the number of moles of saturated aliphatic monocarboxylic acid or hydroxyl group-containing aliphatic monocarboxylic acid and the number of moles of polybasic acids so that the total number of carboxy groups and the total number of amino groups are equivalent. For example, when n moles (n = 0 to 5) of aliphatic dicarboxylic acid, which is a polybasic acid, are used for 2 moles of aliphatic monocarboxylic acid, and the amount of diamine is (n + 1) mole, the acid and amine are equivalent.

[0132] The amide wax may be obtained as a mixture of multiple compounds having different molecular weights. The amide wax is preferably a compound represented by the following chemical formula (I). The amide wax may be a single compound or a mixture: A-C-(B-C) ｍ -A (I) In formula (I), A represents a dehydroxylated residue of a saturated aliphatic monocarboxylic acid and / or a hydroxy group-containing saturated aliphatic monocarboxylic acid, B represents a dehydroxylated residue of a polybasic acid, C represents a dehydrogenated residue of a diamine and / or a tetraamine, and m is 0≦m≦5.

[0133] One preferred embodiment of the aggregation dispersant is a compound represented by the following formula (II).

[0134]

[0135] In formula (II), R １ represents a monovalent linear aliphatic hydrocarbon group having 10 to 25 carbon atoms, and R ２ and R ３ each independently represents a divalent aliphatic hydrocarbon group having 2, 4, 6, or 8 carbon atoms, a divalent alicyclic hydrocarbon group having 6 carbon atoms, or a divalent aromatic hydrocarbon group; R ４ represents a divalent aliphatic hydrocarbon group having 1 to 8 carbon atoms, and R ５ and R ６ each independently represents a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms or a hydroxyalkyl ether group. １ ~L ３ each independently represents an amide bond; L １ and L ３ When is -CONH-, L ２ is —NHCO—, and L１ and L ３ When is —NHCO—, L ２ is -CONH-.

[0136] R １ is a monovalent linear aliphatic hydrocarbon group having 10 to 25 carbon atoms, and examples thereof include linear alkyl groups such as decyl, lauryl, myristyl, pentadecyl, stearyl, palmityl, nonadecyl, eicosyl, and behenyl groups; linear alkenyl groups such as decenyl, pentadecenyl, oleyl, and eicosenyl groups; and linear alkynyl groups such as pentadecynyl, octadecynyl, and nonadecenyl groups. １ is preferably a monovalent linear aliphatic hydrocarbon group having 14 to 25 carbon atoms, more preferably a monovalent linear aliphatic hydrocarbon group having 18 to 21 carbon atoms. The linear aliphatic hydrocarbon group is preferably an alkyl group.

[0137] R ２ and R ３ Examples of the divalent aliphatic hydrocarbon group having 2, 4, 6 or 8 carbon atoms in R include an ethylene group, an n-butylene group, an n-hexylene group, and an n-octylene group. ２ and R ３ Examples of the divalent alicyclic hydrocarbon group having 6 carbon atoms in R include a 1,4-cyclohexylene group, a 1,3-cyclohexylene group, and a 1,2-cyclohexylene group. ２ and R ３ Examples of the divalent aromatic hydrocarbon group in the formula include arylene groups having 6 to 10 carbon atoms, such as a 1,4-phenylene group, a 1,3-phenylene group, and a 1,2-phenylene group.

[0138] Among them, R ２ and R ３ is preferably a divalent aliphatic hydrocarbon group having 2, 4, 6 or 8 carbon atoms, more preferably a divalent aliphatic hydrocarbon group having 2, 4 or 6 carbon atoms, still more preferably a divalent aliphatic hydrocarbon group having 2 or 4 carbon atoms, and still more preferably a divalent aliphatic hydrocarbon group having 2 carbon atoms, in view of its excellent thickening effect. The divalent aliphatic hydrocarbon group is preferably a linear alkylene group.

[0139] R ４ represents a divalent aliphatic hydrocarbon group having 1 to 8 carbon atoms, and among them, a linear or branched alkylene group is preferred, and a linear alkylene group is more preferred, in terms of excellent thickening effect. ４ The carbon number of the divalent aliphatic hydrocarbon group in R is 1 to 8, and from the viewpoint of excellent thickening effect, it is preferably 1 to 7, more preferably 3 to 7, even more preferably 3 to 6, and particularly preferably 3 to 5. Therefore, R ４ is preferably a linear or branched alkylene group having 1 to 8 carbon atoms, more preferably a linear alkylene group having 1 to 7 carbon atoms, still more preferably a linear alkylene group having 3 to 7 carbon atoms, particularly preferably a linear alkylene group having 3 to 6 carbon atoms, and most preferably a linear alkylene group having 3 to 5 carbon atoms.

[0140] R ５ and R ６ Examples of the monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms in the formula (I) include linear or branched alkyl groups having 1 to 3 carbon atoms, such as a methyl group, an ethyl group, a propyl group, and an isopropyl group; linear or branched alkenyl groups having 2 to 3 carbon atoms, such as a vinyl group, a 1-methylvinyl group, and a 2-propenyl group; and linear or branched alkynyl groups having 2 to 3 carbon atoms, such as an ethynyl group and a propynyl group.

[0141] R ５ and R ６ Examples of the hydroxyalkyl ether group in the formula (I) include mono- or di(hydroxy)C groups such as a 2-hydroxyethoxy group, a 2-hydroxypropoxy group, and a 2,3-dihydroxypropoxy group. １－３ Examples include alkyl ether groups.

[0142] Among them, R ５ and R ６ are each independently preferably a monovalent aliphatic hydrocarbon group having 1 to 3 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, still more preferably a linear alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.

[0143] The compound represented by formula (II) is preferably a compound represented by the following formulas (II-1) to (II-9).

[0144]

[0145] Examples of the flocculating dispersant include ANTI-TERRA-203, 204, 206, and 250 (all trade names, manufactured by BYK Corporation); ANTI-TERRA-U (trade name, manufactured by BYK Corporation); DISPER BYK-102, 180, and 191 (all trade names, manufactured by BYK Corporation); BYK-P105 (trade name, manufactured by BYK Corporation); TEGO Disper 630 and 700 (trade names, manufactured by Evonik Degussa Japan Co., Ltd.); TALEN VA-705B (trade name, manufactured by Kyoeisha Chemical Co., Ltd.); and FLOWNON RCM-100, RCM-300TL, and RCM-230AF (trade names, manufactured by Kyoeisha Chemical Co., Ltd., amide wax).

[0146] When the composition contains an aggregating dispersant, the content of the aggregating dispersant is preferably 0.01 to 10 mass %, more preferably 0.01 to 8.0 mass %, and still more preferably 0.01 to 6.0 mass %, relative to the total solid content of the composition.

[0147] (Inorganic thixotropic agents) Examples of inorganic thixotropic agents include bentonite, silica, calcium carbonate, and smectite.

[0148] <Organic solvent> The composition preferably contains an organic solvent. The type of organic solvent is not particularly limited, and examples thereof include ester solvents (preferably acetate solvents), ketone solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents. The organic solvents may be used alone or in combination of two or more.

[0149] The lower limit of the boiling point of the organic solvent is preferably 55° C. or higher, and from the viewpoint of obtaining better effects of the present invention, is more preferably 80° C. or higher, and even more preferably 100° C. or higher. The upper limit of the boiling point of the organic solvent is not particularly limited, but is preferably 400° C. or lower, more preferably 250° C. or lower, even more preferably 225° C. or lower, particularly preferably 200° C. or lower, and most preferably 150° C. or lower.

[0150] Examples of organic solvents include acetone (boiling point 56°C), methyl ethyl ketone (boiling point 79.6°C), ethanol (boiling point 78.4°C), cyclohexane (boiling point 80.8°C), ethyl acetate (boiling point 77.1°C), and ethylene dichloride (boiling point 83.5°C), tetrahydrofuran (boiling point 66°C), cyclohexanone (boiling point 155.6°C), toluene (boiling point 110°C), ethylene glycol monomethyl ether (boiling point 124°C), ethylene glycol monoethyl ether (boiling point 135°C), ethylene glycol dimethyl ether (boiling point 84°C), propylene glycol monomethyl ether (boiling point 120°C), propylene glycol monoethyl ether (boiling point 132°C), acetylacetone (boiling point 140°C), cyclopentanone (boiling point 131°C), ethylene glycol Ethylene glycol monomethyl ether acetate (boiling point 144.5°C), ethylene glycol ethyl ether acetate (boiling point 145°C), ethylene glycol monoisopropyl ether (boiling point 141°C), diacetone alcohol (boiling point 166°C), ethylene glycol monobutyl ether acetate (boiling point 192°C), 1,4-butanediol diacetate ("1,4-BDDA", boiling point 232°C), 1,6-hexanediol diacetate ("1,6-HDDA", boiling point 260°C), 1,3-butylene glycol 1,3-BGDA, boiling point 232°C), propylene glycol diacetate (PGDA, boiling point 190°C), glycerol triacetate (boiling point 260°C), 3-methoxy-1-propanol (boiling point 150°C), 3-methoxy-1-butanol (boiling point 161°C), diethylene glycol monomethyl ether (boiling point 194°C), diethylene glycol monoethyl ether (boiling point 202°C), diethylene glycol dimethyl ether (boiling point 162°C), diethylene glycol diethyl ether (boiling point Examples of suitable solvents include propylene glycol monomethyl ether acetate (PGMEA, boiling point 146°C), propylene glycol monoethyl ether acetate (boiling point 146°C), N,N-dimethylformamide (boiling point 153°C), dimethyl sulfoxide (boiling point 189°C), γ-butyrolactone (boiling point 204°C), ethyl acetate (boiling point 77.1°C), butyl acetate (boiling point 126°C), methyl lactate (boiling point 144°C), N-methyl-2-pyrrolidone (boiling point 202°C), and ethyl lactate (boiling point 154°C).

[0151] When the composition contains an organic solvent, the content of the organic solvent is preferably 1.0 to 10.0% by mass relative to the total mass of the composition.

[0152] <Curing Agent> The composition may contain a curing agent. Examples of the curing agent include phenol-based curing agents, naphthol-based curing agents, acid anhydride-based curing agents, active ester-based curing agents, benzoxazine-based curing agents, cyanate ester-based curing agents, carbodiimide-based curing agents, and amine adduct-based curing agents. One type of curing agent may be used alone, or two or more types may be used in combination.

[0153] Specific examples of phenol-based curing agents and naphthol-based curing agents include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Chemical Industry Co., Ltd.; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-375", and "SN-395" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; and "LA-7052", "LA-7054", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", and "TD-2090-60M" manufactured by DIC Corporation.

[0154] Examples of acid anhydride curing agents include curing agents having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. anhydride, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and polymeric acid anhydrides such as styrene-maleic acid resins in which styrene and maleic acid are copolymerized. Examples of commercially available acid anhydride curing agents include "HNA-100," "MH-700," "MTA-15," "DDSA," "HF-08," and "OSA" manufactured by New Japan Chemical Co., Ltd., "YH306" and "YH307" manufactured by Mitsubishi Chemical Corporation, "H-TMAn" manufactured by Mitsubishi Gas Chemical Company, Inc., and "HN-2200," "HN-2000," "HN-5500," and "MHAC-P" manufactured by Hitachi Chemical Co., Ltd.

[0155] As the active ester curing agent, a compound having three or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, is preferably used. As the active ester curing agent, an active ester compound containing a dicyclopentadiene-type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of phenol novolac, or an active ester compound containing a benzoylated product of phenol novolac is preferred. Note that the "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentalene-phenylene.

[0156] Commercially available active ester curing agents include active ester compounds containing a dicyclopentadiene-type diphenol structure, such as "EXB9451," "EXB9460," "EXB9460S," "HPC-8000," "HPC-8000H," "HPC-8000-65T," "HPC-8000H-65TM," "EXB-8000L," and "EXB-8000L-65TM" (manufactured by DIC Corporation); active ester compounds containing a naphthalene structure, such as "EXB9416-70BK" and "EXB-8150-65T" (manufactured by DIC Corporation); and phenol novolac. Examples of active ester compounds containing an acetylated product of phenol novolac include "DC808" (manufactured by Mitsubishi Chemical Corporation); active ester compounds containing a benzoylated product of phenol novolac include "YLH1026" (manufactured by Mitsubishi Chemical Corporation); active ester-based curing agents that are acetylated products of phenol novolac include "DC808" (manufactured by Mitsubishi Chemical Corporation); and active ester-based curing agents that are benzoylated products of phenol novolac include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation).

[0157] Specific examples of benzoxazine-based curing agents include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation; "HFB2006M" manufactured by Showa Polymer Co., Ltd.; and "P-d" and "F-a" manufactured by Shikoku Chemicals Corporation.

[0158] Specific examples of cyanate ester-based curing agents include "PT30" and "PT60" (both of which are phenol novolac-type multifunctional cyanate ester resins), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazinated to form a trimer), all of which are manufactured by Lonza Japan Co., Ltd.

[0159] Specific examples of carbodiimide curing agents include "V-03" and "V-07" manufactured by Nisshinbo Chemical Inc.

[0160] Commercially available amine adduct curing agents include, for example, Amicure PN-23 and PN-50 (both manufactured by Ajinomoto Fine-Techno Co., Ltd.).

[0161] When the composition contains a curing agent, the ratio of the content of the binder component to the content of the curing agent is such that the equivalent ratio ("total number of epoxy groups and oxetanyl groups") / "number of reactive groups") of the epoxy groups and oxetanyl groups in the binder component to the reactive groups in the curing agent (active hydrogen groups such as hydroxyl groups in the curing agent) is preferably 30 / 70 to 70 / 30, more preferably 40 / 60 to 60 / 40, and even more preferably 45 / 55 to 55 / 45. When the composition contains a curing agent, the content of the curing agent is preferably 0.001 to 3.5 mass%, more preferably 0.01 to 3.5 mass%, based on the total solids content of the composition.

[0162] <Curing Accelerator> The composition may contain a curing accelerator. Examples of curing accelerators include triphenylphosphine, methyltributylphosphonium dimethylphosphate, trisorthotolylphosphine, and boron trifluoride amine complex. An example of a commercially available phosphate curing accelerator is Hishicolin PX-4MP (manufactured by Nippon Chemical Industry Co., Ltd.).Other examples of curing accelerators include 2-methylimidazole (trade name: 2MZ), 2-undecylimidazole (trade name: C11-Z), 2-heptadecylimidazole (trade name: C17Z), 1,2-dimethylimidazole (trade name: 1.2DMZ), 2-ethyl-4-methylimidazole (trade name: 2E4MZ), 2-phenylimidazole (trade name: 2PZ), 2-phenyl-4-methylimidazole (trade name: 2P4MZ), and 1-benzyl-2-methylimidazole (trade name: 1B2M Z), 1-benzyl-2-phenylimidazole (trade name: 1B2PZ), 1-cyanoethyl-2-methylimidazole (trade name: 2MZ-CN), 1-cyanoethyl-2-undecylimidazole (trade name: C11Z-CN), 1-cyanoethyl-2-phenylimidazolium trimellitate (trade name: 2PZCNS-PW), 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine (trade name: 2MZ-A), 2,4-diamino-6-[2'-undecylimidazole] midazolyl-(1')]-ethyl-s-triazine (trade name: C11Z-A), 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine (trade name: 2E4MZ-A), 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct (trade name: 2MA-OK), 2-phenyl-4,5-dihydroxymethylimidazole (trade name: 2PHZ-PW), 2-phenyl-4-methyl-5-hydroxy ... Examples of imidazole-based curing accelerators include hydroxymethylimidazole (trade name: 2P4MHZ-PW), 1-cyanoethyl-2-phenylimidazole (trade name: 2PZ-CN), 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine (trade name: 2MZA-PW), and 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct (trade name: 2MAOK-PW) (all manufactured by Shikoku Chemical Industry Co., Ltd.). Furthermore, examples of triarylphosphine-based curing accelerators include the compounds described in paragraph 0052 of JP-A-2004-43405.Examples of phosphorus-based curing accelerators in which triphenylborane is added to triarylphosphine include the compounds described in paragraph 0024 of JP 2014-5382 A. When the composition contains a curing accelerator, the content of the curing accelerator is preferably 0.0002 to 3.0 mass%, more preferably 0.002 to 2.0 mass%, and even more preferably 0.02 to 1.0 mass%, relative to the total solid content of the composition.

[0163] <Other Optional Components> The composition may further contain optional components other than the above-described components. Examples include a sensitizer, a co-sensitizer, a plasticizer, a diluent, an oil-sensitizing agent, a filler (e.g., silica particles), a surfactant, an adhesion aid (a silane coupling agent), and a rubber component. Furthermore, known additives such as auxiliaries (e.g., an antifoaming agent, a flame retardant, a leveling agent, a release accelerator, an antioxidant, a fragrance, a surface tension modifier, and a chain transfer agent) may be added as needed.

[0164] <Physical Properties of Composition> When the rotation speed (shear rate) of the rheometer is 0.1 (1 / s), the viscosity of the composition at 23°C is preferably 1 to 10,000 Pa s, more preferably 1 to 5,000 Pa s, and even more preferably 1 to 1,000 Pa s, from the viewpoint of better sedimentation stability of the magnetic particles. Here, the viscosity of the composition at 23°C can be measured using an MCR-102 (manufactured by Anton Paar).

[0165] <Method for producing the composition> The composition can be prepared by mixing the above-mentioned components by a known mixing method (for example, a mixing method using a stirrer, kneader, homogenizer, high-pressure emulsifier, wet grinder, wet disperser, or the like). When preparing the composition, the components may be blended all at once, or each component may be dissolved or dispersed in a solvent and then blended sequentially. The order of addition and working conditions when blending are not particularly limited. For example, when multiple types of other resins are used, they may be blended all at once, or each type may be blended in multiple batches.

[0166] [Method for producing magnetic body] The magnetic body of the present invention can be formed from the above-mentioned composition. As a method for producing the magnetic body of the present invention, a production method including steps 1 and 2 is preferable, since it can further reduce voids in the obtained magnetic body and, as a result, further improve the magnetic permeability of the magnetic body. Step 1: A step of preheating a composition containing magnetic particles and a resin precursor or a resin at 100 to 170°C. Step 2: A step of further heating the composition obtained in step 1 at 180 to 220°C.

[0167] Each step will be described below. [Step 1] Step 1 preferably comprises a composition layer forming step of forming a composition layer from the above-described composition, and a preheating step of preheating the composition layer at 100 to 170°C. <Composition Layer Forming Step> The composition layer forming step is preferably a step of applying a composition to the surface of a substrate or to holes (via holes, through holes, etc.; the holes may be through holes or blind holes) provided in the substrate to form a layer of the composition (composition layer).

[0168] (Substrate) Examples of the substrate include a glass substrate, a glass epoxy substrate (e.g., an FR-4 substrate), a silicon substrate, a resin substrate, and a substrate having a conductive layer. The substrate may be composed of a light-transmitting substrate such as a glass substrate. Examples of the substrate include tempered glass such as Gorilla Glass (manufactured by Corning Incorporated). In addition, examples of materials that can be contained in the substrate include the materials used in JP 2010-086684 A, JP 2010-152809 A, and JP 2010-257492 A. Examples of the resin substrate include polyethylene terephthalate (PET), polyethylene naphthalate, polycarbonate, triacetyl cellulose, cycloolefin polymer, and polyimide.

[0169] An example of a substrate having a conductive layer is a resin substrate having a conductive layer. An example of the conductive layer is a conductive layer used for circuit wiring. The conductive layer is preferably at least one selected from the group consisting of a metal layer (e.g., metal foil, etc.), a conductive metal oxide layer, a graphene layer, a carbon nanotube layer, and a conductive polymer layer, more preferably a metal layer, and even more preferably a copper layer or a silver layer. The conductive layer in the substrate having a conductive layer may be one layer or two or more layers. When the substrate having a conductive layer includes two or more conductive layers, the conductive layers may be the same or different, and preferably different. Examples of materials for the conductive layer include simple metals and conductive metal oxides. Examples of simple metals include Al, Zn, Cu, Fe, Ni, Cr, Mo, Ag, and Au. Examples of conductive metal oxides include ITO (indium tin oxide), IZO (indium zinc oxide), and SiO ２ Conductivity is defined as a material having a volume resistivity of 1×10 ６ It means that the volume resistivity is less than 1×10 ４ Preferably, the resistivity is less than Ωcm. When the conductive layer-containing substrate has two or more conductive layers, it is preferred that at least one of the conductive layers contains a conductive metal oxide. The substrate may or may not have holes.

[0170] (Method of Forming Composition Layer) As a method of applying the composition to the surface of a substrate and a method of filling holes provided in the substrate with the composition, various application methods can be applied, such as slit coating, inkjet coating, spin coating, cast coating, roll coating, screen printing, etc. When a composition layer is formed on the surface of a substrate, the film thickness of the composition layer is, for example, preferably 1 to 10,000 μm, more preferably 10 to 1,000 μm, and even more preferably 15 to 800 μm.

[0171] The composition used in step 1 may be the composition described above. The composition contains magnetic particles and a resin precursor or a resin. The resin precursor and resin typically correspond to the binder component, which is one of the components of the composition described above.

[0172] <Preheating Step> The preheating step is a step of subjecting the composition layer obtained in the composition layer forming step to a heat treatment at 100 to 170°C. Examples of the heating method in the heat treatment include heating methods using a hot plate and an oven. The heating temperature is more preferably 130 to 150°C. The heat treatment time is preferably 10 to 120 minutes, more preferably 20 to 90 minutes, and even more preferably 30 to 90 minutes.

[0173] [Step 2] Step 2 is a step of further heating the composition obtained in step 1 at 180 to 220°C. Specifically, step 2 is preferably a step of further main-heating the composition layer that has been subjected to pre-heating treatment in step 1 at 180 to 220°C (main-heating step). Examples of heating methods for the heat treatment include heating methods using a hot plate, a convection oven (a hot air circulation dryer), and a high-frequency heater. The heating temperature is more preferably 180 to 200°C. The heat treatment time is preferably 10 to 200 minutes, more preferably 30 to 120 minutes.

[0174] The heat treatments in steps 1 and 2 may be carried out either continuously or batchwise. Furthermore, after carrying out step 1 and before carrying out step 2, a step of cooling the composition (a step of cooling the composition layer) may be included. When the composition is cooled, the temperature of the composition layer after cooling (in other words, the temperature of the composition layer before being subjected to step 2) is preferably 15 to 40°C, more preferably 20 to 30°C. By carrying out step 2, the curing reaction of the composition layer is promoted and a magnetic body is formed.

[0175] Furthermore, when the composition layer forming step is a step of forming a composition layer in a hole provided in a substrate, it is also preferable to include a step 3, after carrying out step 2, in which unnecessary portions of the magnetic material obtained by step 2 that protrude from the substrate surface are removed by physical polishing to form a flat surface.

[0176] Furthermore, the method may include a step 4 of drilling holes in the magnetic material provided on the substrate after carrying out the step 3. The drilling can be carried out by using a drill, a laser, plasma irradiation, or the like.

[0177] Furthermore, after carrying out step 3 or step 4, step 5 may be included in which a conductor layer is formed by wet plating on at least a portion of the polished surface of the magnetic body in step 3 or on at least a portion of the surface of the magnetic body on which holes have been drilled in step 4.

[0178] [Substrate with magnetic body] The substrate with magnetic body of the present invention includes a substrate having a hole and a magnetic body arranged in the hole. Specific examples of the substrate in the substrate with magnetic body of the present invention include those exemplified in the upper section as substrates that can be used in the method for manufacturing a magnetic body of the present invention. The magnetic body corresponds to the magnetic body of the present invention. The substrate with magnetic body of the present invention can be manufactured by the method for manufacturing a magnetic body of the present invention using a substrate with a hole, as explained in the upper section.

[0179] [Electronic Component] The electronic component of the present invention includes the magnetic material described above. That is, the electronic component of the present invention may include the magnetic material described above as a part of the component. Examples of the electronic component include an inductor and an antenna. The electronic component may have a known structure.

[0180] The present invention will be described in more detail below based on examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the examples shown below. In the following, unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

[0181] [Various Components Contained in the Composition] The various components used in preparing the composition are listed below.

[0182] [Magnetic Particles] The magnetic particles shown in the "Magnetic Particles" column in Table 2 are shown below.・P-1: Mn-Zn ferrite (spherical magnetic particles, D50: 0.2 μm) ・P-2: Mn-Zn ferrite (spherical magnetic particles, D50: 1.0 μm) ・P-3: Mn-Zn ferrite (spherical magnetic particles, D50: 3.0 μm) ・P-4: Mn ferrite (spherical magnetic particles, D50: 41 μm) ・P-5: Mn ferrite (spherical magnetic particles, D50: 0.4 μm) ・P-6: Mn ferrite (spherical magnetic particles, D50: 4.0 μm) ・P-7: Ni-Zn-Co ferrite (spherical magnetic particles, D50: 40 μm) ・P-8: Product name "Kuamet 6B2" (manufactured by Epson Atmix Corporation, spherical magnetic particles, D50: 25 μm) P-9: Product name "AW02-08PF3F" (manufactured by Epson Atmix Corporation, spherical magnetic particles, D50: 3.0 μm)

[0183] [Thioctropic Agent] The various components shown in the "Thioctropic Agent" column in Table 1 are listed below. S-1: Product name "FLOWNON RCM-100" (manufactured by Kyoeisha Chemical Co., Ltd.) S-2: Product name "Tallen VA705B" (manufactured by Kyoeisha Chemical Co., Ltd.)

[0184] [Dispersant] The various components shown in the "Dispersant" column in Table 1 are shown below. S-3: The following compound (weight average molecular weight 10,000). The number attached to each repeating unit in the main chain represents the mass ratio, and the number attached to each side chain represents the number of repeats.

[0185]

[0186] S-4: Product name "Hinoact T-6000" (manufactured by Kawaken Fine Chemical Co., Ltd.) S-5: Product name "SC-1015F" (manufactured by NOF Corporation)

[0187] [Curing components] The various components shown in the "Curing components" column in Table 1 are listed below. S-6: Product name "ADEKA RESIN EP-4000L" (manufactured by ADEKA Corporation; corresponds to an epoxy compound containing an aromatic ring.) S-7: Product name "Denacol EX-614" (manufactured by Nagase ChemteX Corporation; corresponds to an epoxy compound containing no aromatic ring.) S-8: Product name "JER871" (manufactured by Mitsubishi Chemical Corporation; corresponds to an epoxy compound containing no aromatic ring.) S-9: Product name "ZX-1059" (manufactured by Nippon Steel Chemical & Material Corporation; corresponds to an epoxy compound containing an aromatic ring.) S-10: Product name "JER630" (manufactured by Mitsubishi Chemical Corporation; corresponds to an epoxy compound containing an aromatic ring.)

[0188] [Additives] The various components shown in the "Additives" column in Table 1 are listed below. S-11: Product name "Hishicolin PX-4MP" (phosphate-based epoxy curing accelerator, manufactured by Nippon Chemical Industry Co., Ltd.) S-12: Product name "2MZA-PW" (2-ethyl-4-methylimidazole (curing accelerator), manufactured by Shikoku Kasei Holdings Co., Ltd.) S-13: Product name "SO-C2" (silica particles, manufactured by Admatechs Co., Ltd.) S-14: Product name "KBM-573" (N-phenyl-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0189] [Solvent] The various components shown in the "Solvent" column in Table 1 are as follows: L-1: 1,6-HDDA (manufactured by Daicel Corporation) L-2: Glycerol triacetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) L-3: Butyl carbitol acetate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0190] [Measurement of element ratio of magnetic material] <Preparation of evaluation sample substrate (substrate with magnetic material)> A coating film was obtained by applying the composition shown in Table 1 to a Si wafer with a thickness of 0.7 mm using an applicator with a gap of 100 μm. The obtained coating film was then heated in an oven at 150° C. for 20 minutes, and then further heated in an oven at 180° C. for 90 minutes to cure the coating film, thereby preparing a substrate with magnetic material (substrate with cured film).

[0191] When application with an applicator was not possible, the composition was poured flat into a frame-shaped frame with a height of 1 mm and an inner width of 30 mm, and pressed to harden, thereby obtaining a coating film. The coating film was then heated in an oven at 150°C for 20 minutes, and then further heated in an oven at 180°C for 90 minutes to harden the coating film, thereby producing a substrate with a magnetic material (substrate with a cured film).

[0192] <Measurement of elemental ratio of magnetic material> The elemental ratio of the magnetic material was measured using the method described in the upper part. Specifically, the magnetic material of the substrate with the magnetic material was subjected to sputtering of approximately 50 nm on the sample surface using an Ar ion beam (acceleration voltage: 1 kV). Then, XPS measurement was performed using monochromated Al Kα radiation as the X-ray source and a photoelectron take-off angle of 45°. The peak areas of the photoelectron spectrum of the C 1s, N 1s, O 1s, Si 2s, Mn 2p 3 / 2, Fe 2p, Co 2s, Ni 2p, and Zn 2p 3 / 2 orbitals were quantified, and the obtained peak areas were converted to element concentrations using relative sensitivity coefficients (Note that in measurements from Example 2 onwards, when peaks of other elements were observed, quantification was performed using the peak areas of the photoelectron spectrum of orbitals that did not overlap with the peaks).

[0193] [Evaluation] [Magnetic permeability evaluation] A substrate with a magnetic material was produced using the same procedure as in <Production of evaluation sample substrate> above. Next, the magnetic properties (relative magnetic permeability (μ'A) at 60 MHz) of the magnetic material in the evaluation sample substrate was measured using PER-01 (a high-frequency magnetic permeability measuring device manufactured by Keycom Co., Ltd.). From the viewpoint of practicality, an evaluation result of "3" or higher is preferable, "4" is more preferable, and "5" is even more preferable. The results are shown in Table 3. <Evaluation criteria> "5": 20<μ'A "4": 17<μ'A≦20 "3": 15<μ'A≦17 "2": 10<μ'A≦15 "1": μ'A≦10

[0194] [Hardness Evaluation] A substrate with magnetic material was prepared using the same procedure as in <Preparation of Evaluation Sample Substrate> above. Next, the Vickers hardness (HV) of the magnetic material of the substrate with magnetic material was measured using a microhardness tester HM500 (manufactured by Fisher Instruments). The measurement was performed 30 times at different measurement locations on the magnetic material (cured film), and the average value was calculated. From the viewpoint of practicality, an evaluation result of "3" or higher is preferable, and "4" is even more preferable. The results are shown in Table 3. <Evaluation Criteria> "4": 30<HV "3": 20<HV≦30 "2": 10<HV≦20 "1": HV≦10

[0195] [Heat Resistance Evaluation] A substrate with magnetic material was prepared using the same procedure as described above in <Preparation of Sample Substrate for Evaluation>. Next, the magnetic material (cured film) portion of the substrate with magnetic material was scraped off with a spatula to obtain a powdered sample. The sample was weighed and subjected to thermogravimetric measurement using a thermogravimetric analyzer (TA Instruments Q500) to determine the weight loss rate over a temperature range of 180 to 350°C. The measurement conditions were a nitrogen atmosphere, a measurement temperature range of 23 to 500°C, and a heating rate of 10°C / min. The weight loss rate was calculated using the following formula (1): Weight loss rate (mass%) = {1 - (mass of sample at 350°C) / (mass of sample at 180°C)} × 100. From the perspective of practicality, a rating of "3" or higher is preferable, with "4" being more preferable and "5" being even more preferable. The results are shown in Table 3. <Evaluation criteria> "5": Thermogravimetric reduction rate <1% "4": 1% ≦ thermogravimetric reduction rate < 2% "3": 2% ≦ thermogravimetric reduction rate < 3% "2": 3% ≦ thermogravimetric reduction rate < 5% "1": 5% ≦ thermogravimetric reduction rate

[0196] [Evaluation of Humidity Resistance] Substrates with magnetic material were prepared using the same procedure as in <Preparation of Evaluation Sample Substrate> above. The substrates with magnetic material were then left to stand for 500 hours under high temperature and high humidity conditions of 85°C and 85% humidity. A PER-01 (a high-frequency magnetic permeability measuring device manufactured by Keycom Corporation) was used to measure the magnetic properties of the film in each evaluation sample substrate before and after the high temperature and high humidity test (relative magnetic permeability (μ'A) at 60 MHz before the high temperature and high humidity test, and relative magnetic permeability (μ'B) at 60 MHz after the high temperature and high humidity test). Δμ' was then calculated using the following formula, and the obtained value was used as an index of deterioration of the magnetic material due to the high temperature and high humidity test. Formula (2) Δμ'=1-μ'B / μ'A From the viewpoint of practicality, a rating of "3" or higher is preferable, with "4" being more preferable and "5" being even more preferable. The results are shown in Table 3.

[0197] <Evaluation criteria> "5": Δμ'<0.01 "4": 0.01≦Δμ'<0.05 "3": 0.05≦Δμ'<0.1 "2": 0.1≦Δμ'<0.2 "1": 0.2≦Δμ'

[0198] [Production and Evaluation of Magnetic Materials of Examples 2 to 10 and Comparative Examples 1 to 4] Evaluation sample substrates (substrates with magnetic material) of Examples 2 to 10 and Comparative Examples 1 to 4 were produced and evaluated in the same manner as in Example 1, except that the compositions for forming the magnetic materials were changed to compositions 2 to 10 and comparative compositions 1 to 4 shown in Table 1.

[0199] [Production and Evaluation of Magnetic Material of Comparative Example 5] [Preparation of Comparative Composition 5] 87 parts by mass of Mn—Zn ferrite, 3 parts by mass of Sendust alloy, and 10 parts by mass of ethylene-vinyl acetate resin were mixed and placed in a sealed container made of PTFE (polytetrafluoroethylene). The container was then sealed, and the mixture was dispersed at 50 G for 1 hour using a RAM (low frequency resonant acoustic mixer) manufactured by Resodyn Corporation, to prepare Comparative Composition 5.

[0200] [Preparation and evaluation of magnetic body of comparative composition 5] An evaluation sample substrate (substrate with magnetic body) of comparative example 5 was prepared and evaluated in the same manner as in Example 1, except that the composition for forming the magnetic body was changed to comparative composition 5.

[0201] Tables 1 to 3 are shown below. Table 1 shows the composition of each composition (excluding Comparative Composition 5) used to prepare the magnetic bodies of the Examples and Comparative Examples. Table 2 shows the elemental composition of the magnetic bodies obtained from each composition of the Examples and Comparative Examples. Each elemental composition is shown as the content (atm %) relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms. Table 3 shows the evaluation results of the magnetic bodies obtained from each composition of the Examples and Comparative Examples.

[0202]

[0203]

[0204]

[0205] The results in Table 3 clearly show that the magnetic bodies of the examples are excellent in all of moisture resistance, heat resistance, magnetic permeability, and hardness. Furthermore, a comparison of Examples 1 to 4 confirmed that when the carbon atom content of the magnetic body is 5.0 atm% or more relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, the hardness is superior. Furthermore, a comparison of Examples 1 to 4 confirmed that when the carbon atom content of the magnetic body is 9.0 atm% or less relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, the heat resistance is superior. Furthermore, a comparison of Examples 1 to 4 confirmed that when the metal atom content of the magnetic body is 38.0 atm% or more relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, the magnetic permeability is superior. Furthermore, a comparison of Examples 2 and 5 confirmed that when the magnetic body contains Co atoms, the magnetic permeability and moisture resistance are superior. Furthermore, a comparison of Examples 2 and 7 to 10 confirmed that when the resin contained in the magnetic body contains a cured product of an epoxy compound having an aromatic ring, the heat resistance is superior.

[0206] [Preparation and Evaluation of Magnetic Material of Example 101] [Preparation of Composition 101] The components listed in Table 1 were mixed to obtain the composition (parts by mass) shown in Composition 1 in Table 1, and then 3 parts by mass of 1,6-HDDA (1,6-hexanediol diacetate, manufactured by Daicel Corporation), 3 parts by mass of glycerol triacetate (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.), and 3 parts by mass of butyl carbitol acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to prepare Composition 101. [Preparation and Evaluation of Magnetic Material of Example 101] An evaluation sample substrate (substrate with magnetic material) of Example 101 was prepared and evaluated in the same manner as in Example 1, except that the composition for forming the magnetic material was changed to Composition 101, and the results were similar to those of the magnetic material of Example 1.

[0207] [Preparation and Evaluation of Magnetic Materials of Examples 102 to 110] Compositions 102 to 110 were prepared in the same manner as composition 101, except that composition 1 was changed to compositions 2 to 10. Evaluation sample substrates (substrates with magnetic material) of Examples 102 to 110 were prepared and evaluated in the same manner as in Example 1, except that the composition for forming the magnetic material was changed to compositions 102 to 110, and the results were similar to those of the magnetic materials of Examples 2 to 10.

Claims

1. A magnetic body comprising magnetic particles and a resin, wherein the content of metal atoms contained in the magnetic body is 35.0 to 50.0 atm% relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, the content of oxygen atoms contained in the magnetic body is 40.0 to 60.0 atm% relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms, and the content of carbon atoms contained in the magnetic body is 3.0 to 12.0 atm% relative to all atoms in the magnetic body excluding hydrogen atoms and helium atoms.

2. The magnetic body according to claim 1, wherein the resin comprises a cured product of an epoxy compound containing an aromatic ring.

3. A magnetic body according to claim 1 or 2, wherein the content of nitrogen atoms contained in said magnetic body is 0.05 to 2.0 atm % relative to all atoms in said magnetic body excluding hydrogen atoms and helium atoms.

4. The magnetic body according to claim 1 or 2, wherein the metal atoms include Fe and Mn.

5. The magnetic body according to claim 4, wherein the metal atoms further include Co.

6. A substrate with a magnetic material, comprising: a substrate having a hole; and the magnetic material according to claim 1 or 2, disposed in the hole.

7. An electronic component comprising the substrate with magnetic material according to claim 6.

8. A method for producing the magnetic material according to claim 1 or 2, comprising: step 1 of preheating a composition containing magnetic particles and a resin precursor or resin at 100 to 170°C; and step 2 of further heating the composition obtained in step 1 at 180 to 220°C.

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